Proceedings of the 20th Annual meeting of the Caribbean Food Crops Society. St. Croix, U.S. Virgin Islands : October 21-...


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Proceedings of the 20th Annual meeting of the Caribbean Food Crops Society. St. Croix, U.S. Virgin Islands : October 21-26, 1984
Series Title:
Proceedings of the ... Annual meeting of the Caribbean Food Crops Society ...
Physical Description:
Caribbean Food Crops Society
Eastern Caribbean Center, College of the Virgin Islands ; Caribbean Food Crops Society
Publication Date:


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Source Institution:
University of Virgin Islands
Holding Location:
University of Virgin Islands
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All applicable rights reserved by the source institution and holding location.
Resource Identifier:
notis - AAA7020
notis - ABD6367
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Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
        Errata 1
        Errata 2
    Title Page
        Page i
    Front Matter
        Page ii
    Table of Contents
        Page iii
        Page iv
        Page v
        Page vi
        Page 1
        Page 2
    Presidential address : Innovative technologies for enhancing food production capabilities in the Caribbean
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
    Keynote Address : A new era of agriculture
        Page 9
        Page 10
    Closing remarks at the CFCS banquet, October 25, 1984
        Page 11
        Page 12
    Minutes : 20th Annual Meeting of Caribbean Food Crops Society
        Page 13
        Page 14
    Country and Historical Papers
        Page 15
        Page 16
        Small-scale agriculture in the United States Virgin Islands, 1930-1983
            Page 17
            Page 18
            Page 19
            Page 20
            Page 21
            Page 22
        The Decline of agriculture and projection of the number of farm units in the United States Virgin Islands
            Page 23
            Page 24
            Page 25
            Page 26
            Page 27
            Page 28
            Page 29
        The Caribbean food crop society : how it all started
            Page 30
            Page 31
            Page 32
    Technical Papers
        Page 33
        Page 34
        Defoliators and sap sucking insects of Pigeon-Pea in Barbados, West Indies
            Page 35
            Page 36
            Page 37
        Pigeon-Pea pod borers and their natural enemies in Barbados, West Indies
            Page 38
            Page 39
            Page 40
            Page 41
        Control of Harrot or fatal wilt of coconut palm
            Page 42
            Page 43
            Page 44
        Use of open versus closed systems in Caribbean prawn hatcheries
            Page 45
            Page 46
        Developing pest management strategies for small farmers based on traditional knowledge
            Page 47
            Page 48
            Page 49
            Page 50
        Small farming systems in Las Cuevas watershed, Dominican Republic
            Page 51
            Page 52
            Page 53
            Page 54
            Page 55
        Predators and parasites of insect pests on cantaloupe and asparagus bean, St. Croix, U.S. Virgin Islands
            Page 56
            Page 57
            Page 58
            Page 59
            Page 60
        Vagility and probability of survival in two weevils (Coleoptera, Curculionidae) the sugarcane rootstalk borer weevil ...
            Page 61
            Page 62
            Page 63
            Page 64
            Page 65
        Beekeeping in the Caribbean
            Page 66
            Page 67
        Etude de la matiere organiques des sols par fractionnement granulometrique ...
            Page 68
            Page 69
            Page 70
            Page 71
            Page 72
            Page 73
        Foliar analysis as a diagnostic technique in tropical horticulture
            Page 74
            Page 75
            Page 76
        Adaptation of CIMMYT's high protein quality corn varieties to Puerto Rico
            Page 77
            Page 78
            Page 79
            Page 80
        Some factors affecting the adoption of hand tractors by vegetable farmers in Trinidad
            Page 81
            Page 82
            Page 83
            Page 84
        Jojoba - an alternative agriculture in the Caribbean area
            Page 85
            Page 86
            Page 87
        Etude preliminaire a l'utilisation de deux baculovirus dan la lutte contre Spodoptera frugiperda en prarie guyanaise a Digitaria swazilandensis
            Page 88
            Page 89
            Page 90
            Page 91
            Page 92
        Biological basis for the breeding of better food yams
            Page 93
            Page 94
            Page 95
        Farmers' adaptations to production constraints and its implications for agricultural research : the case of rice production systems in the Dominican Republic
            Page 96
            Page 97
            Page 98
            Page 99
        Recent advances in research on control and biology of pickeworm and melonworm
            Page 100
            Page 101
            Page 102
        Nouvell strategie de protection des cultures vivrieres contre la fourmi attine Acromyrmex octospinosus (Reich) in Guadeloupe : les plantes resistantes a la defoliation
            Page 103
            Page 104
            Page 105
            Page 106
        Farming Systems : an effective methodology for rapid agricultural change
            Page 107
            Page 108
            Page 109
            Page 110
        A classification of farming systems in the Eastern District of Dominca
            Page 111
            Page 112
            Page 113
            Page 114
        Integrated dairy managment for the Caribbean
            Page 115
            Page 116
            Page 117
        Development and implementation of Greenhouse operations : a case study
            Page 118
            Page 119
        Agronomic characteristics of confectionery sunflower grown in Florida, USA
            Page 120
            Page 121
            Page 122
            Page 123
            Page 124
            Page 125
            Page 126
            Page 127
        The problem of cocomut mite, Eriophyes guerreronis (Keifer), in the coconut groves of Trinidad and Tobago
            Page 128
            Page 129
            Page 130
            Page 131
            Page 132
        Weed control in small farm systems
            Page 133
            Page 134
            Page 135
            Page 136
        Some perspectives on the role of aquaculture in the development of small farm systems for the Eastern Caribbean
            Page 137
            Page 138
            Page 139
            Page 140
            Page 141
            Page 142
            Page 143
        Prospects for control of the vector of lethal yellowing on small coconut farms
            Page 144
            Page 145
            Page 146
        Effects of high pH on Macrobrachium rosenbergii postlarvae
            Page 147
            Page 148
        Selecting appropriate equipmetn for small farms
            Page 149
            Page 150
            Page 151
            Page 152
            Page 153
        Experience with behaviour-modifying chemicals for insect control
            Page 154
            Page 155
            Page 156
            Page 157
        El cultivo del Name (Dioscorea spp.) y de Otoe (Xanthosoma spp.) en la Provincia de Herrera, Panama
            Page 158
            Page 159
            Page 160
            Page 161
        El cultivo del Tiquisque (Xanthosoma spp.) la Malanga (Colocasia esculenta), el Name (Dioscorea spp.) y el Platano (Musa sp AAB) en Costa Rica
            Page 162
            Page 163
            Page 164
            Page 165
            Page 166
            Page 167
            Page 168
        El cultivo del Queuisque (Xanthosoma spp.) y Platano (Musa sp AAB) en el Tropico Humedo y Bajo de Nicaragua
            Page 169
            Page 170
            Page 171
            Page 172
        Pest management and the vegetable farmer in Trinidad and Tobago
            Page 173
            Page 174
            Page 175
        Use of Bacillus thuringiensis in Pest Management of the tomato ecosystem in Trinidad
            Page 176
            Page 177
            Page 178
            Page 179
        USDA initiatives to assist small scale agriculture
            Page 180
            Page 181
        The quest for increased food production in the Caribbean
            Page 182
            Page 183
        Responses to several sub-tropical crops to applications of Humus and marine materials
            Page 184
            Page 185
        Non-traditional agriculture for the Caribbean
            Page 186
            Page 187
            Page 188
        Potential for beekeeping expansion in the Caribbean
            Page 189
            Page 190
            Page 191
        North American women and their children : valuable resources in food production
            Page 192
            Page 193
            Page 194
        Studies on soil and water management for small farmers on flat heavy soils in the Caribbean
            Page 195
            Page 196
            Page 197
        Weed competition in transplanted sweet peppers
            Page 198
            Page 199
        Development and characteristics of twining sweet potatoes
            Page 200
            Page 201
        Development of the sweet potato for increased usage in the Caribbean
            Page 202
            Page 203
            Page 204
            Page 205
        Native and introduced legumes in the Virgin Islands : soil improvement and livestock feed
            Page 206
            Page 207
        Potato (Solanum Tuberosum) variety and cost production trial at Mount Wilton, Barbados
            Page 208
            Page 209
            Page 210
            Page 211
        Lethal diseases of coconut palm in the Caribbean region
            Page 212
            Page 213
            Page 214
        Farming strategies for small farmers and limited resource farmers in North Florida through the 80's
            Page 215
            Page 216
        The IR-4 program
            Page 217
            Page 218
        Is it possible to find a third way between "Green Revolution" and traditional systems of agriculture?
            Page 219
            Page 220
            Page 221
        Some complements to prakken's theory of pigmentation of dry Phaseolus Vulgaris beans
            Page 222
            Page 223
        A cost analyss for establishing a Barbados cherry (Malpighia Punicifolia) orchard in Barbados
            Page 224
            Page 225
        The potential of vegetables for meeting World food needs
            Page 226
        Exposure of farm labor to pesticides
            Page 227
            Page 228
            Page 229
            Page 230
            Page 231
        Leucaena as a protein source
            Page 232
            Page 233
            Page 234
            Page 235
        Tilapia fry and fingerling production in small tanks
            Page 236
            Page 237
            Page 238
            Page 239
            Page 240
            Page 241
            Page 242
        Yield, agronomic characteristics and variability of 'regular maricongo' and 'dwarf plaintains' (Musa AAB) using tissue-cultured plantlets in St. Croix, USVI
            Page 243
            Page 244
        Testing the performance of banana cropping systems on farmers' holdings in the Windward Islands
            Page 245
            Page 246
            Page 247
            Page 248
        Social impediments to the cultivation of trees in Jamaica
            Page 249
            Page 250
        Farmland management and biosphere reserves in the lesser Antilles
            Page 251
            Page 252
            Page 253
        Introduction of clean Dioscorea Alata planting material into small farm systems of Dominica
            Page 254
            Page 255
            Page 256
            Page 257
            Page 258
        Respuesta del Nampi (Colocasia esculenta var. antiquorum) al espaciamiento baja dos condiciones de fertilidad
            Page 259
            Page 260
            Page 261
            Page 262
            Page 263
        Technical and economic parameters for the adoption of solar drying systems on small farms
            Page 264
            Page 265
            Page 266
        Breeding tomatoes for all seasons
            Page 267
            Page 268
            Page 269
            Page 270
        international food marketing stratedgies for island economies : a case of the Eastern Caribbean
            Page 271
            Page 272
            Page 273
            Page 274
            Page 275
            Page 276
            Page 277
            Page 278
        Post harvest losses in fruit and vegetables, their extent and methods of control
            Page 279
            Page 280
            Page 281
        Breeding and agronomic studies with sorghum in Puerto Rico
            Page 289
            Page 290
            Page 291
            Page 292
        Mosaic disease control on susceptible cucurbits in the West Indies
            Page 293
            Page 294
            Page 295
        Prospection de materiaux organiques utilisables en amendement du sol pour controler le Sclerotium Rolfsii Sacc.
            Page 296
            Page 297
            Page 298
            Page 299
            Page 300
        The USAID agroforestry systems : an alternative to meeting Haiti's food, fiber and fuel needs
            Page 301
            Page 302
            Page 303
            Page 304
        An integrated approach to small farmers' development in the OECS countries - the CARDATS experience
            Page 282
            Page 283
            Page 284
            Page 285
            Page 286
            Page 287
            Page 288
        Industrializing small-scale food processing
            Page 305
            Page 306
        Preliminary investigations for biological control of Brassolis sophorae in Guyana
            Page 307
            Page 308
    Translations of the Abstracts (Spanish)
        Page 309
        Page 310
        Page 311
        Page 312
        Page 313
        Page 314
        Page 315
        Page 316
        Page 317
        Page 318
        Page 319
        Page 320
    Translations of the abstracts (French)
        Page 321
        Page 322
        Page 323
        Page 324
        Page 325
        Page 326
        Page 327
        Page 328
        Page 329
        Page 330
        Page 331
        Page 332
        Page 333
        Page 334
        Page 335
    Back Cover
        Page 336
Full Text

Vol. XX


Sociedad Caribefia de Cultivos Alimenticios
Association Caraibe des Plantes Alimentaires


Published by


CFCS will not provide reprints of papers presented' in these PROCEEDINGS.
Duplication, in any form, is permitted on condition that full credit be given the


and that the date of publication and volume number be stated.

Contact address for information regarding CFCS:
CFCS Secretariat
P.O. Box 506

Isabela, PR 00662

Contact address for information regarding PROCEEDINGS:

CFCS Editors
R.R. 02, Box 10051, Kingshill
St. Croix, USVI 00850

CFCS is not responsible for the contents, style or quality of tables/illustrations of
submitted papers.

Our gratitude goes to the editors and translators of Spanish and French papers and

Carlos Cruz Luis Calduch S. Lugo
Rodrigue Aristide Ricardo Cortes M. Mangual

F. Abruna Agenol Gonzalez S. M. Medina
N. Acin H. Irizarry O. Ramierez
J. Arroyo George C. Jackson R. del Valle
The CFCS meeting was held in conjunction with the Caribbean Aquaculture Associa-
tion whose presentations are included in these PROCEEDINGS.

Page iii Paper No. 6: Dates should read "1930-1983" not "1930-1932."

iv Paper 3, Col 1: "Farmers'" not "Farmer's"; Paper 5, Col. 1: "(Reiche)" not
"Reiche"; Paper 6, Col. 1: Additional author-"J.R. Rich"; Paper 11, Col. 1:
"(Keifer)" not "Keifer'; Paper 5, Col. 2: "Platano" not "Plaatano."

v Paper 14, Col 1: Additional author-"M. Oakes"; Paper 3, Col. 2: "Respuesta"

not "Repuesta"; Paper 7, Col. 2: Additional author-'J.C. Royer."

68 In title: "Organique" not "Organiques"; "Enfoui" not "Enfoi".

100 Author's address: USDA-ARS-SR, Vegetable Laboratory, Charleston, SC, USA.
128 In abstract and text: "(Keifer)" not "Keifer".

158 In abstract: "30%" not "301s".

169 In abstract and text: "25%" not "251s".

206 In Materials and Methods: "Neonotonia" not "Neotonia".

225 Figures missing. See below and at right.

254 In title: "Dioscorea alata" not "Dioscorra Alata".

296 In title: "Sclerotium rolfsii" not "Sclerotium Rofsii".

Pages 309/321 Intro. pages of French and Spanish abstracts should be reversed.



Item Unit Quantity Price Cost

Variable Expenses

Trees Acre
Fertilizer Kg.
Herbicide Gal.
Misc. Acre


2.75 536.25
.40 60.00
86 172.00
50 50.00


Tree Planting Acre 1 66 66.00
Other Acre 1 45 45.00


Bulldozing &
Harrowing Acre
Mowing Acre
Interest on Variable
Expenses $
Total Variable Expense

Fixed Costs

Tractor Hr.
Land Acre
Vehicle Mile
Overhead $
Management $
Total Fixed Costs
Total Per Acre
Establishment Costs








10 240.00
100 100.00
.25 25.00
5% 65.48
5% 65.48
$ 495.96


Unit Quantity Price Cost



2.75 536.25
.40 60.00
86 172.00
50 50.00

1 106 106.00
1 66 66.00
1 45 45.00



Variable Expenses

Trees Acre
Fertilizer Kg.
Herbicide Gal.
Misc. Acre


Tree Planting


Bulldozing &
Harrowing Acre 1 150
Mowing Acre 3 x/Yr. 90
Irrigation Acre 25,000 gals. .0024/
Interest on Variable
Expenses $ 1,335.25 12%
Total Variable Expense

Fixed Costs




S 751.75


Total Fixed Costs
Total Per Acre
Establishment Costs


Item Unit Quantity Price

Variable Expenses




Tree Planting


Acre 195
Kg. 150
Gal. 2
Acre 351,000 Gal.

Acre 1

Acre 1
Acre 1
Acre 1

Bulldozing &
Harrowing Acre
Mowing Acre
Interest on Variable
Expenses $
Total Variable Expense

Fixed Costs

Total Fixed Costs
Total Per Acre
Establishment Costs









135 135.00
66 66.00
45 45.00






$ 875.36






System Item Group Cost % Of Total

Non-Irrigated Supplies $818 45%
Labour 111 6%
Machinery $505 28%
Land $100 6%
Interest, Overhead
Management $270 15%

Drip Irrigation Supplies $878 39%
S Labour 3217 10%
S Machinery $742 33%
Land S100 4%
Interest, Overhead
Management $309 14%

Micro-Spray Supplies $902 37%
Labour $246 10%
Machinery $859 36%
Land 8100 4%
Interest, Overhead
Management $321 13%

Sociedad Caribefia de Cultivos Alimenticios
Association Caralbe des Plantes Alimentaires


Vol. XX

Edited by
Robert Webb
Walter Knausenberger
Lisa Yntema

Published by
The Eastern Caribbean Center
College of the Virgin Islands
The Caribbean Food Crops Society

Copyright 01985
by the

The Caribbean Food Crops Society is not responsible for statements and
opinions advanced in its meetings or printed in its PROCEEDINGS; they
represent the views of the individuals to whom they are credited and are not
binding on the Society as a whole.

REPRINTS: Reprints may be made from this publication on condition that
full credit be given the PROCEEDINGS of the CARIBBEAN FOOD
CROPS SOCIETY and the authorss, and that the date of publication and
volume number be stated.

was printed in St. Croix, USVI, by Antilles Graphic Arts.
Layout and Typography by New Image Graphics, St. Croix, USVI.




Vol. XX


Foreword .................. .......... ..... ...... ....1
Arthur A. Richards, President
College of the Virgin Islands
CFCS Presidential Address:
Innovative Technologies for enhancing Food Production
Capabilities in the Caribbean. ........... ..... ............ .. 3
Darshan S. Padda, Vice-President
Research and Land-Grant Programs,
College of the Virgin Islands
CFCS Keynote Address:
A New Era of Agriculture .................... ...........9.. 9
Orville G. Bentley
Asst. Secretary for Science and Education
U.S. Department of Agriculture
Closing Remarks at the CFCS Banquet, October 25, 1984 ........... 11
Alejandro Ayala, Chairman
CFCS Board of Directors
Minutes- 20th Annual Meeting of the
Caribbean Food Crops Society ................................. 13

Small-Scale Agriculture in the U.S. Virgin Islands
1930-1932 ................ ................................ 17
Jerome McElroy, St. Mary's College
Notre Dame, IN, USA
Klaus de Albuquerque, College of Charleston
Charleston, SC, USA

The Decline of Agriculture and the Projection
of the Number of Farms in the U.S. Virgin Islands................23
Frank L. Mills, College of the Virgin Islands

CFCS-How it All Started ............... ................. 30
Hugh Miller, Founding Member

Defoliators and Sap Sucking Insects
of Pigeon-Pea in Barbados, W.I ............................. 35
M.M. Alam and I.H. Gibbs
Barbados, WI
Pigeon-Pea Pod Borers and Their Natural Enemies
in Barbados, W.I. ................ ........................ 38
M.M. Alam and I. H. Gibbs
Barbados, WI
Control of Hartrot or Fatal Wilt of Coconut Palm .................. 42
V.T. Alexander, Ministry of Agriculture
Suriname, South America

Use of Open Versus Closed Systems
in Caribbean Prawn Hatcheries .............................. 45
D.E. Alston, University of Puerto Rico, and
F. Ibaiez, Aquaculture Enterprises, Inc., Puerto Rico

Developing Pest Management Strategies for Small Farmers
Based on Traditional Knowledge .......................... 47
M.A. Altieri, University of California
Berkeley, CA, USA

Small Farming Systems in Las Cuevas Watershed,
Dominican Republic ....................... ............ 51
J. Alvarez, P.E. Hildebrand, and J.A. Nova
Santo Domingo, Dominican Republic

Predators and Parasites of Insect Pests on Cantaloupe
and Asparagus Beans, St. Croix, U.S. Virgin Islands ...............56
R.G. Bland, Central Michigan University, USA, and
W.I. Knausenberger, CVI Agricultural Experiment
Station, St. Croix, USVI

Vagility and Probability of Survival in Two Weevils
(Coleoptera, Curculionidae): The Sugar Cane Rootstock
Borer Weevil (Diaprepes abbreviatus L.) and the
Sweet Potato Weevil (Cylasformicarius F.) ....................... 61
L. Bonnefil-Bauduy,
Inter-American University, Puerto Rico

Beekeeping in the Caribbean ............... ................66
R.A. Breyer, Michigan State University, USA
E. Harris, and T. Sorhaindo
Ministry of Agriculture, Dominica, W.I.

Etude de la Matiere Organique des Sols
par Fractionnement Granulometrique.
1 Decomposition au Champ d'un Compost
Enfoui dans Plusieurs Types de Sols des Antilles ................ 68
M. Brossard, A. Balesdent, C. Feller,
A. Plenecassagne, et J.F. Turenne,
Laboratoire Matiere Organique et des Sols,
Martinique, F.W.I.

Foliar Analysis as a Diagnostic Technique
in Tropical Horticulture ................. ................... 74
G.A. Cahoon, Ohio State University, USA

Adaptation of CIMMYT's High Protein Quality
Corn Varieties in Puerto Rico ............... ................ 77
C. Cardona, L. WesseI-Beaver, and P. R. Hepperly,
College of Agricultural Sciences,
University of Puerto Rico
Some Factors Affecting the Adoption
of Hand Tractors by Vegetable Farmers in Trinidad ................ 81
W.G. Clark, Geo. F. Huggins & Co., Ltd., and
P.I. Gomes, University of the West Indies,
Trinidad, W.I.
Jojoba-An Alternative Agriculture in the
Caribbean Area ................... .................... 85
R.C. Cutting, Jr., R.C. Cutting & Co., MA, USA

Etude Preliminaire a 1'Utilisation de Deux
Baculovirus dans la Lutte Contre Spodoptera
frugiperda en Prairie Guyanaise a Digitaria
Swazilandensis ................... ... ............. 88
D. Dauthuille, etJ.F. Silvain,
Centre ORSTOM de Cayenne, Guyane Frangaise

Biological Basis for the Breeding of Better Yams ................... 93
L.M. Degras, Station d'Amelioration des Plantes,
INRA, Guadeloupe, F.W.I.

Farmer's Adaptations to Production Constraints,
and Its Implications for Agricultural Research;
The Case of Rice Production Systems in the
Dominican Republic ........................ ....... 96
F. Doorman, CENDA, and F. Cuevas Perez, ISA,
Dominican Republic, W.I.

Recent Advances in Research on Control and
Biology of Pickleworm and Melonworm ....................... 100
K.D. Elsey, J. Pena, J. Peterson, and T. Wehner
USDA-ARS, SR, U.S. Vegetable Laboratory,
Charleston, SC, USA

Nouvelle Strategie de Protection des Cultures
Vivrieres centre la Fourmi Attine Acromyrmex
octospinosus Reiche en Guadeloupe: les Plantes
Resistantes a la Defoliation. ................... ... ....... 103
G. Febvay, et A. Kermarrec
INRA, Guadeloupe, F.W.I.

Farming Systems: Effective Methodology for
Rapid Agricultural Change .................................. 107
E.C. French, E. Martinez, D.L. Schmidt, and M.E. Swisher
University of Florida, USA

A Classification of Farming Systems in the
Eastern District of Dominica ................................. 111
M. Genthon, French Technical Cooperation Office
Dominica, W.I.

Integrated Dairy Management for the Caribbean ................. 115
C.D Gibson, Michigan Stae University, USA, and
H. Hupp, College of the Virgin Islands, St. Croix

Development and Implementation of Greenhouse
Operations-A Case Study................................. 118
R.E. Gomez, USDA, Washington, DC, USA

Agronomic Characteristics of Confectionery
Sunflower Grown in Florida ................................ 120
V.E. Green, Jr., IFAS, University of Florida, USA

The Problem of the Coconut Mite Eriophyes guerreronis
Keifer, in the Coconut Groves of Trinidad and Tobago ............ 128
R. Griffith, Red Ring Research Division,
Ministry of Agriculture, Trinidad, W.I.

Weed Control in Small Farm Systems ............ . . ... 133
J.L. Hammerton, CARDI, St. Lucia, W.I.

Some Perspectives on the Role of Aquaculture in the
Development of Small Farm Systems for the
Eastern Caribbean............................. ............ 137
J.A. Hargreaves, CVI Agricultural Experiment Station
St. Croix, USVI

Prospects for Control of the Vector of Lethal Yellowing
on Small Coconut Farms .................. ......... ... 144
F.W. Howard, University of Florida, USA

The Effects of High pH on Macrobrachium
rosenbergii Postlarvae .................. ................... 147
C.G. Hummel, and D.E. Alston
University of Puerto Rico

Selecting Appropriate Equipment for Small Farms ................ 149
G.W. Isaacs, University of Florida, USA

Experience with Behavior-Modifying Chemicals
for Insect Control ............... ....................... 154
J.W. Jenkins, and C.C. Doane
Pest Select International, Inc., AZ, USA

El Cultivo del Name (Dioscorea spp.) y de Otoe
(Xanthosoma spp.) en la Provincia de Herrera, Panama............ 158
J. Jimenez and W.G. Rodriguez, CATIE, Costa Rica

El Cultivo del Tiquisque (Xanthosoma spp.), La Malanga
(Colocasia esculenta), el Iame (Dioscorea spp.) y el
Plaatano (Musa sp AAB) en Costa Rica ........................ 162
J. Jimenez, A. Rodriguez and W.G. Rodriguez
CATIE, Costa Rica

El Cultivo del Quequisque, (Xanthosoma spp.) y Platano
(Musa sp. AAB) en el Tr6pico Hufmedo y Bajo de Nicaragua ........ 169
J. Jimenez and W.G. Rodriguez, CATIE, Costa Rica

Pest Management and the Vegetable Farmer
in Trinidad and Tobago ................ .................. 173
M.T. Jones, Central Experiment Station
Trinidad, W.I.

Use of Bacillus thuringiensis in Pest Management
of the Tomato Ecosystem in Trinidad .......................... 176
M.T. Jones, Central Experiment Station
Trinidad, W.I.

USDA Initiatives to Assist Small scale Agriculture ................ 180
H.W. Kerr, Jr., USDA, Washington, DC, USA

The Quest for Increased Food Production
in the Caribbean ...................... ................ 182
M.A. Kigoda and M.G. Blase
University of Missouri, Columbia, MO, USA

Responses of Several Sub-Tropical Crops
to Applications of Humus and Marine Materials .................. 184
A.R. Kingman, Diversified Marketing Services
St. Thomas, USVI

Non-Traditional Agriculture for the Caribbean .................. 186
A. Krochmal and C. Krochmal
University of North Carolina, USA

Potentials for Beekeeping
Expansion in theCaribbean ................... ........ .189
C. Krochmal and A. Krochmal
University of North Carolina, USA

North American Women and Their Children:
Valuable Resources in Food Production ................. . 192
H.K. Light and D. Hertsgaard
North Dakota State University, USA

Studies on Soil and Water Management for Small Farmers
on Flat Heavy Soils in the Caribbean ........... . . ... 195
J.I. Lindsay, S.A. Simpson, and F.A. Gumbs
The University of the West Indies, Trinidad, W.I.

Weed Competition in Transplanted Sweet Peppers ............... 198
L.C. Liu, J. Gonzilez-Ibafiez, and M.R. Goyal
Agricultural Experiment Station, Puerto Rico

Development and Characteristics of Twining Sweet Potatoes........ 200
F.W. Martin, USDA-ARS, Tropical Agriculture
Research Station, Puerto Rico

Development of the Sweet Potato for Increased Usage
in the Caribbean ........................................ 202
F.W. Martin, USDA-ARS, Tropical Agriculture
Research Station, Puerto Rico

Native and Introduced Legumes in the Virgin Islands:
Soil Improvement and Livestock Feed .......................... 206
J.M. Matuszak, College of the Virgin Islands,
St. Thomas, USVI

Potato (Solanum tuberosum) Variety and Cost Production
Trial at Mount W ilton, Barbados .......................... 208
A. Maynard, MAFCA,
V. Ojeda, IICA,
and B. Clarke, MAFCA, Barbados, W.I.

Lethal Diseases of Coconut Palm in the Caribbean ................ 212
E. McCoy, University of Florida, USA

Farming Strategies for Small Farmers and Limited Resource
Farmers in North Florida Through the '80's ................... .. 215
G.A. McWhorter, Florida A&M University, USA

The IR-4 Program .............. ....................... 217
C.W. Meister, IFAS-University of Florida, USA

Is It Possible to Find a Third Way Between
"Green Revolution" and Traditional Systems
of Agriculture? ............................................ 219
C.M. Messiaen, INRA, Guadeloupe, F.W.I.

Some Complements to Prakken's Theory for Pigmentation
of Dry Phaseolus vulgaris Beans ............................... 222
C.M. Messiaen, G. Anais, and C. Vincent
INRA, Guadeloupe, F.W.I.

A Cost Analysis for Establishing a Barbados Cherry
(Ma/pighiapunicifolia) Orchard in Barbados ....................224
S. Michelini, FRESCA, Barbados, W.I.

The Potential of Vegetables for Meeting World Food Needs ........ 226
H.M. Munger, Dept. of Vegetable Crops and
Plant Breeding, Cornell University, USA

Exposure of Farm Labor to Pesticides ......................... 227
H.N. Nigg and J.H. Stamper
University of Florida, IFAS, USA
Leucaena as a Protein Source ................... .. ... .232
A.J. Oakes, St. Croix, USVI
Tilapia Fry and Fingerling Production in Small Tanks ............. 236
J.E. Rakocy and A. Nair, CVI
Agricultural Experiment Station, St. Croix, USVI

Yield, Agronomic Characteristics and Variability of
'Regular Maricongo' and 'Dwarf Plantains' (Musa AAB)
Using Tissue-Cultured Plantlets in St. Croix, USVI ............... 243
C. Ramcharan and A. Gonzalez, CVI
Agricultural Experiment Station, St. Croix, USVI
Testing the Performance of Banana Cropping Systems
on Farmers' Holdings in the Windward Islands................... 245
M.M. Rao, H. Murray, and J.E. Edmunds
WINBAN, St. Lucia, W.I.
Social Impediments to the Cultivation of Trees
inJam aica ............................ .................. 249
J.H. Rashford, the College of Charleston, SC, USA

Farmland Management and Biosphere Reserves
in the Lesser Antilles .............. ..................... 251
J. Riddle, Virgin Islands National Park
St. Thomas, USVI

Introduction of Clean Dioscorea alata Planting Material
into Small Farm Systems of Dominica ......................... 254
G. Robin, S. Bellon, B. Clarke,
H. Adams, and M. Genthon
CARDI and French Technical Cooperative
Dominica, W.I.

Repuesta del Nampi (Colocasia esculenta var.
antiquorum) al Espaciamiento bajo Dos Condiciones
de Fertilidad ......................... ................. 259
W.G. Rodriguez, J.M. Jimenez y J.M. Elizondo
CATIE, Costa Rica

Technical and Economic Parameters for the Adoption
of Solar Drying Systems on Small Farms ...................... .264
K. Sankat, University of the West Indies, Trinidad, W.I.

Breeding Tomatoes for All Seasons ........................ 267
J.W. Scott, W.L. George, Jr.
Gulf Coast Research & Education Center, Florida, USA

International Food Marketing Strategies for Island
Economies: A Case of the Eastern Caribbean .................... 271
S. Sentongo-Kabuka, Jr.
CVI, St. Thomas, USVI

Post-Harvest Losses in Fruits and Vegetables,
Their Extent and Methods of Control ............... ........ 279
R.K. Shukla, Dominica Agricultural
Marketing Board, Dominica, W.I.

An Integrated Approach to Small Farmers' Development
in the OECS Countries -The CARDATS Experience .............. 282
H. Singh and G. McSween, Caribbean Agricultural
Rural Development, Grenada, W.I.

Breeding and Agronomic Studies with Sorghum
in Puerto Rico ................ .........................289
A. Sotomayor-Rios and S. Torrest-Cardona
USDA-ARS. Tropical Agriculture Research Station
Puerto Rico

Mosaic Disease Control on Susceptible Cucurbits
in the West Indies. ................ ...................... 293
O.S. Lloyd Thomas, Ministry of Agriculture
Barbados, W.I.

Prospection de Materiaux Organiques Utilisables
en Amendement du Sol Pour Controler le Sclerotium
Rolfsii Sacc.................................. .............. .296
J.A. Toribio, Station de Pathologie Vegetale
INRA, Guadeloupe, F.W.I.

The USAID Agroforestry Systems--An Alternative
to Meeting Haiti's Food, Fiber and Fuel Needs ................... 301
A.H. Wahab, V. Cusumano and G.W. Koehler
SAID, Haiti

Industrializing Small-Scale Food Processing ................... 305
R.H. Walter, Cornell University, NY, USA

Preliminary Investigations for Biological Control
of Brassolis sophorae in Guyana ......... ............ 307
M.Yaseen, CIBC, Trinidad, W.I.

Translations of Abstracts (French) ............... .......... 309

Translations of Abstracts (Spanish) ................. ......... 321

i bLR



Arthur A. Richards
College of the Virgin Islands

In October of 1984 I had the distinct pleasure of welcoming a record number of partici-
pants to the annual meeting of the Caribbean Food Crops Society on St. Croix. I express a
great deal of pride on behalf of all the dedicated people of the College of the Virgin Islands
who organized and hosted the meeting activities. Further I express particular pride in the
fact that the 1984 conference was extremely successful in its objective to provide a forum for
knowledge to be shared among the region's professional work force concerned with the
problems of human welfare through agricultural improvements.
The College of Virgin Islands is very pleased to sponsor the publication of the pro-
ceedings of the 1984 meeting. It is hoped that this document would be of benefit in carry-
ing forward the concept of the Caribbean community as an interdependent entity striving
to resolve quality of life problems for all the citizenry. This document also represents a
milestone for the College because its publication represents the first formal output of CVI's
Eastern Caribbean Center.
The Center will be a collaborative endeavor between CVI and the people of the island na-
tions of the Eastern Caribbean, offering cooperative programs of study, research, and train-
ing. The Center, as proposed, is designed to address problems of the region by working
within the framework of established regional institutions, including the University of the
West Indies, by encouraging cooperation between the nations of the Eastern Caribbean and
the United States through this collaborative endeavor.
Documentation proves that the similarity of culture and language, the commonality of
problems, the existing family ties with the people of the Eastern Caribbean and a diversity
of expertise available at CVI, combine to make the Center uniquely suited to contribute
meaningfully to the educational, economic, and social development of the Eastern Carib-
bean, supplementing the efforts of the governments, other institutions and the people of
the region.
To accomplish this task, the College supports for the Center initiatives in five interdepen-
dent areas: agriculture and natural resources, human resource development training and
education, social and environmental research and development, telecommunications, and
scholarship assistance.
We look forward with great anticipation to the role of the College of the Virgin Islands
and its Eastern Caribbean Center to serve as a catalyst for educational, technical, scientific
and cultural interchange among the Caribbean Nations.


Presidential Address:

Innovative Technologies for Enhancing

Food Production Capabilities in the Caribbean

Darshan S. Padda
Vice-President for Research and
Land-Grant Programs
College of the Virgin Islands

Fellow agricultural scientists, it is a great privilege and honor for me to deliver this presidential
address at the 20th annual homecoming meeting of the Caribbean Food Crops Society. The first
general meeting of the Society was held on St. Croix from October 7 to 11, 1963 under the leader-
ship of the late Dr. R.M. Bond.
Since the first meeting of the Society, the Caribbean region has undergone major changes-
changes that are political, economic, social, demographic and technological in nature. There has
been welcomed economic and political progress in the Caribbean. This progress is generally ex-
pressed in statistics that are macroeconomic descriptions. But in actuality, these statistics translate
into human problems, problems of people: lack of opportunity for growth and inability to share
the prosperity.
In spite of a tremendous growth in tourism and tourist related industries, the majority of the
Caribbean people still live in rural areas that depend on agriculture. Their numbers are growing
each year. They seek a secure food supply, stable employment and the hope for upward mobility
so that they can have decent housing, education for their children and economic independence for
their families. They are looking for a road that will lead them toward these goals. For rural people
who love the land, agriculture can provide a stable, respectable, dignified and independent pur-
suit leading to the attainment of these goals. However, the Caribbean farmer, like any other
farmer in the world, cannot do it alone. He needs help. And we, the agricultural scientists, have
the obligation and opportunity to provide that help. The goal for us is clear. The food import bills
for Caribbean countries have more than doubled since 1975, while the average growth rate in the
agricultural sector has slumped to approximately 2% a year compared to 4 to 6% in the 1970s.
With half of the export earnings of 27 countries included in the Caribbean Basin Initiative (CBI)
coming from agriculture and with most of the population living in rural areas, a sound farm
economy is essential.


While discussing agriculture in the Caribbean, the important concept of 'microstate" must be
recognized. Simply put, the concept brings to focus problems and opportunities connected with
small size. An idea of the small nature of the economies in the English-speaking Caribbean can be
obtained from the fact that the total population of the 12 nation CARICOM is a little over 5
million. Only three members have populations exceeding the 250,000 mark: Guyana with over
800,000, Jamaica with 2 million and Trinidad and Tobago with a little over 1 million. Under the
microstate situation every function must be inter-dependent, and an integrated approach has to
be pursued to achieve results. This concept will help us to understand why farming system ap-
proach is the most appropriate for the small farms. When we discuss small farms we cannot think
only of introducing agricultural technology, but we should be concerned with the economic, social
and educational status of these farm families. We have to look at the total picture with respect to
the farm and farm family as a unit. Low incomes, teenage pregnancy, school dropouts, juvenile
delinquency, and disintegration of families into single-parent households are some real concerns
of the farm families and must be addressed as a part of the total package.
This paper discusses, in a broader sense than the title may imply, innovative technologies for
enhancing food production. The question before us is how to define innovative technology. It can
be defined as the introduction of new or unique methods to bring about change. But, it can be
asked--Why do we need innovative technologies; and what is wrong with our traditional
technologies? The necessity for innovation is dictated by two facts:
1. Our land and water resources are limited and under increasing competitive pressure from
developers; and
2. Food needs are increasing due to growth of resident and visitor populations.
Since we cannot enhance our natural resources we must enhance their productivity. Due to limited
land and water resources, competition and animosity has developed between agriculture and non-
agriculture industries in the Caribbean. What needs to be understood is that no single industry
can survive alone under microstate situations. Agriculture is needed to provide a stable economy
and employment for indigenous populations. Non-agricultural industries, especially tourism, are
needed to provide necessary capital for economic development and a ready market for agricultural
Before discussing specific technologies that are appropriate for the Caribbean, permit me to list
some of the food and agricultural issues that, in my opinion, are priorities in the Caribbean. These
1. Strengthening and diversification of agriculture;
2. Market identification and development;
3. Human resource development;
4. Natural resources and forestry;
5. Integrated rural development;
6. Appropriate mechanization and irrigation technology;
7. Pest and pesticide management; and
8. Development and transfer of technology.
The Caribbean area is very heterogeneous in nature. In addition to water that separates our
island nations, there are language differences, political differences and economic differences.
However, there are great similarities in agro-climatic factors, socio-cultural factors and ecological
The College of the Virgin Islands, through its Experiment Station and Extension Service, has
worked on these priority issues that I have mentioned and has developed appropriate technologies
to improve small and commercial farming systems in the Virgin Islands and other Caribbean
islands. I would like to share with you some of our work that has bearing on these priority issues.
Agriculture is no longer a simple enterprise involved in raising crops and animals. Modern
agriculture is an art, a business, a technology, and a way of life. Therefore, any strengthening and
diversification efforts should be in keeping with these factors. In 1972, we started with a series of
economic feasibility studies covering various agriculture enterprises. We selected certain enter-
prises which have stood the test of time and we initiated research and educational efforts to im-
prove those enterprises. For example, Senepol cattle were developed on St. Croix in 1917 by a
layman farmer. It was considered to be a good breed of cattle due to its docile nature, its resistance
to tropical pests and diseases and its excellent growth rate without any supplemental feeding.
However, due to the lack of characterization of the breed, it was sold for beef purposes for $200 to
$500 per head, depending on the age. Our programs have helped to organize the farmers into a
Senepol Association and have collected scientific data on the breed through performance and car-
cass evaluation. Within three years, St. Croix farmers exported their first shipment of Senepol cat-
tle at $2,000 to $5,000 per head. The innovation here was to develop the cattle as a breeding stock.
Other factors adversely affecting the local livestock industry were the high cost of imported feed
and lack of roughage during dry months. We started developing new technologies to alleviate
these problems. Grain and forage sorghum cultivars were introduced and tested. Within the first
three years a cultivar was recommended that yielded four times more than the locally grown one.
Production studies showed that spring planting produced significantly higher yields than fall plan-
ting. Additionally, sudan grass was found to be quick in regrowth, high yielding and to have good


resistance to lodging and insect pests. The roughage shortage during dry seasons was solved
through improving the forage value of local guinea grass that grows as a weed everywhere. An ap-
plication of 30 pounds nitrogen per acre improved the yield 1.5 times, with 4% higher digestible
proteins. We invited a U.S. company to come here to try bailing guinea grass, an endeavor which
proved to be highly successful. These may not look like sophisticated technologies, but they pro-
duced problem-solving results.
Agricultural Diversification
We explored the possibilities of growing grapes in the Virgin Islands, since only an intensive
crop with high income possibilities could prove profitable in such a location with high land value
and costly labor. With the introduction of tropical cultivars and proper vine management, en-
couraging results have been achieved. However, additional testing is needed before profitability
can be determined. There are many other crops that can be explored for possible commercial pro-
According to Dr. Noel Vietmeyer of the National Academy of Sciences, of the 80,000 species of
edible plants in the world, there are only 100 we grow to any reasonable extent and understand
scientifically. And of those 100 crops, only 20 to 22, most initially domesticated in the Stone Age,
basically feed the world. Rice, wheat and corn account for the bulk of calories and protein eaten.
No new major crop has been domesticated in 10,000 years. Dr. Ferguson of the University of the
West Indies echoed similar feelings through his paper entitled, "Some Underexploited Crops in
the Caribbean" presented at the seminar on agricultural research and small farm productions held
in Jamaica in December 1982. The participants at that seminar recommended that an agricultural
development effort in the Caribbean emphasize the proper utilization of existing technology,
create or adapt new technology when needed, and transfer this technology in the most effective
manner to the small farmers of the region.
Another enterprise with a tremendous potential for enhancing food production in the Carib-
bean is aquaculture. In the Virgin Islands we have studied three methods of tilapia culture.
Tilapia, a tropical, freshwater, food fish, is easily cultured in a wide range of systems. The culture
of tilapia in cages is the best method in areas with existing farm ponds. This method promotes
multiple use of a resource that is often under-utilized and allows diversification of a farming
operation. Pond culture is the best method in areas with a good source of water. It involves the
construction of shallow ponds that can be drained for harvesting. Pond culture of tilapia can be
readily integrated into a farming operation. Tilapia, a filter feeding fish that prefers vegetable pro-
tein, will grow well on agricultural by-products and animal manure. The nutrient enriched water
of fish ponds is ideal for irrigating crops. A third method being explored consists of a series of
tanks in which the fish cultured water is continually purified and reused. This is a closed recir-
culating system whose by-products include sludge which can be used for composting and high
waste nutrient levels that can be used as a nutrient source for vegetable hydroponics.
Market Identification and Development
A fundamental component of increased production of traditional crops or the development of
under-exploited crops, is the assurance that markets exist or are being developed to accommodate
such production. While developing marketing strategies in the Caribbean, overemphasis is given
to export, and tremendous local markets are left open for importers. In some countries, what is
produced is exported and what is consumed is imported. In the majority of cases, something has to
be exported to keep a balance-of-payment, and agricultural commodities are the only items
available for export. In the Virgin Islands, many years ago, we thought of developing 'Solo' papaya
production for shipping to mainland markets. Our commissioner of agriculture took a sample to
New York City and received an open offer from a broker to accept all that we could produce.
When the story hit the newspapers, telephones started ringing. The manager of Caneel Bay Hotel
on St. John questioned the need to ship to New York when he was importing large quantities of
'Solo' papayas for his guests.
Of course, we realize that as part of the U.S. we do not have to worry about balance-of-
payment. In the case of other Caribbean nations, the Caribbean Basin Initiative has offered duty
free access, since January 1984, to U.S. markets for certain goods produced in the Caribbean. I
participated in a recent Agricultural Marketing Workshop for the Caribbean Basin held in Miami,
Florida and observed a strong interest by U.S. importers to find out what agricultural commodities
they can expect from the Caribbean. Development of much needed infrastructure for storage and
processing of local foods is another avenue to explore in market development.
Human Resource Development
Development and transfer of technology at local levels is vital to any drive to modernize and
diversify agriculture in the Caribbean. No matter how much money is invested in the agriculture
sector, success or failure ultimately depends on the strength and development of human resource.
It is imperative that, while innovative technologies are explored for use in the Caribbean, the most
essential resource, the human factor, also be developed. Without it there can be no conversion of
knowledge to technology, no translation of technology to productivity, and no application of pro-
ductivity to an improved quality of life. In December, 1983, I participated in a UNICA-sponsored
workshop on teaching agriculture and was impressed with the recommendations made by the
group. I hope their recommendations can be implemented.


Natural Resources and Forestry
Most of the Caribbean nations have experienced tremendous growth in both permanent and
transient populations. In the Virgin Islands our population has, for example, doubled in the last
ten years. More and more land is being used for housing, roads and shopping centers. The natural
landscape is changing and trees are disappearing. In many Caribbean areas, these land changes
and clearing of vegetation are upsetting the ecological balance.
Preservation of genetic diversity in local plant and animal species is necessary to secure supplies
of food and preserve our natural resources and wild life. It is also necessary to ensure that the loss
of species does not impair the effective functioning of ecological processes. The preservation of
genetic diversity is both a matter of insurance and investment, necessary to sustain and improve
agricultural, forestry and fisheries production, to keep open future options as a buffer against harm-
ful environmental changes, and as the raw material for much scientific and industrial innovation.

Integrated Rural Development
In order to bring about any meaningful change in agricultural production in the Caribbean, an in-
tegrated rural development is of paramount importance. Caribbean farmers live in rural areas and, in
order to achieve success, priority must be given to involve them in policy making and implementa-
tion processes. Access of rural communities to land, water and other natural resources must be im-
proved. Small rural farmers' access to inputs like seeds, plants, machines, chemicals, markets and
services need to be improved. Delivery structures and institutions that are responsive to farmers'
needs must be established. Special programs to meet rural women's education and training needs
must be given priority. Non-farm rural activities and educational facilities for farm children and
adults must be developed. Greater equity in economic opportunities must be insured in order to
enable small farmers to play an important role in increasing food production. Skyrocketing land
values are squeezing the small farmer out of business, and the national governments must take
steps necessary to ensure that young people who choose to farm have access to land.
Appropriate Mechanization and Irrigation Technology
The use of large size machinery has proven to be inappropriate for most field operations on
small farms and the shallow tropical soils of the Caribbean. Machinery and equipment for small
farms need to be developed on a priority basis. Farmers need to be offered short training courses in
operations and maintenance of farm machines and tools. Mechanization of farms will make farm-
ing more attractive to young people, for if we expect our youth to practice farming, the old tradi-
tional ways have to change and agriculture has to turn into a technology-based business enterprise.
The use of trickle or drip irrigation has revolutionized crop production in the tropics. Surface ir-
rigation results in loss of water and sprinkler systems encourage disease development on crop
foliage. Drip irrigation provides an optimum amount of water to the root zone on a continuous
basis. Our irrigation specialist has produced unbelievable yields of 92.6 tons/ha of tomatoes and
103.6 tons/ha of watermelons.
Pest and Pesticide Management
People love the Caribbean for its year round warm climate and, in fact, the U.S. Virgin Islands
are referred to as an American paradise. Unfortunately, pests also find it a paradise and love it. I
remember a few years ago we were discussing priorities for agricultural research in the Caribbean
and Mr. Dean Davis, a former Agricultural Research Service Area director, asked Jose Vincent
Chandler, who is a highly respected agricultural scientist in Puerto Rico, as to what, in his opinion,
is a priority issue in Caribbean agriculture. Jose thought for a while and said, "If somebody could
develop a pill that could be put in the soil and all plant pests would be controlled I would be very
happy." This illustrates the importance of plant protection in the Caribbean. Keeping in mind the
need for pest control and a sensitivity to the use of chemicals that could hurt fragile ecosystems, in-
tegrated pest management is the most viable solution. Authoritative identification of pest,
beneficial and non-target organisms is fundamental to effective pest management. We are pro-
viding diagnostic and referral services on insects, plant diseases, nematodes and weeds, to our
clientele in the Virgin Islands. Also, in tropical climates pesticides deteriorate easily and proper
storage use and disposal safeguards need to be developed.
Development and Transfer of Technology
Effective research and extension are vital to any drive to modernize agriculture in the Carib-
bean. Whereas we must be aware of the large body of knowledge available at major universities
and international agricultural research centers around the world, we must awaken to the fact that
testing that knowledge under local conditions, demonstration of new technology, and finally the
adoption of new practices by the Caribbean farmer is our responsibility. We need to develop
regional research efforts in certain areas. However, the experimental and demonstration work on
each island is still the basic need. Additionally, continuing education of the farmer in all areas of
agriculture, including production, post-harvest technology and marketing, is of paramount im-
portance. We need vocational agriculture schools, junior colleges, and internship programs for
senior undergraduates and graduate students. Most of the students from the Virgin Islands go to
mainland universities for advanced college educations in agriculture and home economics, but we


keep in touch with them and encourage them to return home for summer jobs every year. This
provides mutually beneficial interaction and local experience for prospective research and exten-
sion workers. Another area needing immediate attention is improving communication between
scientists and extension workers in the region. Teleconferences and other modern communication
technologies need to be used.
In conclusion, let me emphasize that Caribbean agricultural scientists need to have a broad
awareness which includes areas like biotechnology, electronic technology, technologies and produc-
tion systems to encourage increased efficient use and conservation of natural resources, new food
preservation and storage techniques, understanding the ecological components of the agricultural
production system and increasing awareness of social implications in technology development.
However, the need of the day is an interdisciplinary approach to solve farm problems. We need to
look at the whole without over-emphasizing the parts. We need to improve the whole farm rather
than just crop production, animal production or marketing. In view of this need, farming system ap-
proach and on-the-farm testing approach are the most appropriate strategies for upgrading
agriculture in the region. The agricultural development effort at the national level should include
formation of an Agricultural Development Council. This Council should serve as an umbrella to
cover all aspects of agriculture in research, extension, education, marketing, regulation and policy
issues. Agriculture Development Councils should develop a national agenda for agricultural develop-
ment. In the same way, there has to be regional coordination effort to multiply our limited resources
and avoid costly duplication. The UNICA's commission on agriculture drafted a plan of action along
these lines.
My friends, the secret of keeping the agriculture industry in the Caribbean alive is integration
and coordination. Let us work together, as our task is big and choices limited. In a region where
there is quite enough that divides us, let us cherish whatever unites us and work as partners in pro-
gress towards satisfying the food needs of our people, while protecting the environment and con-
serving our natural resources of soil, water, flora and fauna.



OCT 2 3 U4

Dr. Darshan S. Padda
President, Caribbean Food Crops Society
Director, Land-Grant Programs
College of the Virgin Islands
P.O. Box L, Kingshill
St. Croix, Virgin Islands 00850

Dear Dr. Padda:

I have asked Assistant Secretary Bentley to extend my personal greetings
to you and the members of the Caribbean Food Crops Society on the
occasion of the twentieth annual meeting of the Society.

For two decades the Society has provided important leadership in the
development of agriculture in the Caribbean. There have been many
changes in this area in the past twenty years. It is appropriate to
note that the challenges of change have been met by the agricultural
leadership of the area.

The progress which has been made is the result of a team effort. The
U.S. Department of Agriculture's Science and Education Agencies, the
Caribbean Association of Universities, the Food Crops Society and the
farmers have worked together for the common goals of improving agriculture.

Thank you for your efforts in the past and I know we can look forward
with great confidence to the future.


".Q4 S6z


Keynote Address:

A New Era of Agriculture

Orville G. Bentley
Assistant Secretary for Science and Education
U.S. Department of Agriculture

It is an honor to represent my colleagues in the Science and Education agencies of the U.S. Department of
Agriculture and Secretary Block at this 20th Annual Meeting of the Caribbean Food Crops Society here in St.
Croix. Secretary Block has asked me to bring his special greetings to your group, and I am pleased to read this
statement from him now.
Program planning and coordination are critical steps in developing a sound, effective system of research,
teaching, and extension education in agriculture and our food production system. Our system of publicly-sup-
ported programs in agricultural research is a joint undertaking, involving the federal, state, and local govern-
ments. This week-long conference is an outstanding demonstration of the vitality of this approach and of its
dedication to public service. These efforts are made all the more impressive when they include active and viable
linkages to the private sector as well. We salute the Agricultural Experiment Station, the Extension Service, the
College of the Virgin Islands, and members of the Caribbean Food Crops Society on their past contributions
and the leadership these groups are giving to agriculture in the Caribbean Basin Region.
I want to say that this cooperative effort involves several agencies of the Department of Agriculture, includ-
ing, of course, the Agricultural Research Service (ARS), the Animal and Plant Health Inspection Service
(APHIS), and undoubtedly others.
True, these occasions are for reflection, and perhaps a bit of self-indulgence on our part. But most important-
ly, this is a time for a realistic stock-taking and a time to direct our thoughts to the future and the opportunities
and challenges it holds.
My personal involvement with the programs in the Caribbean region is limited, but I did have the oppor-
tunity to work with the fine people at the College of Agriculture at the University of Puerto Rico in Mayaguez.
This was when I was Dean of the College of Agriculture at the University of Illinois.
The University of Puerto Rico was a partner with Illinois University in the International Soybean Research
Program (INTSOY) and provided a valuable tropical and semi-tropical component for the program. One of the
side benefits of this program to me was the opportunity to know and work with Chancellor Sol Alemany and
Dean Ayala.


I have also visited the Agricultural Research Service's Tropical Research Station at Mayaguez, and note there
has been extensive involvement in this week's session of Agricultural Research Service (ARS), Cooperative State
Research Service (CSRS), and Extension Service (ES) personnel, reflecting their participation in plans to
strengthen the President's Caribbean Basin Initiative. Dr. Darshan Padda, Director of the Experiment Station,
and Vice-President for Research and Land Grant Program at the College of the Virgin Islands, has an important
role in these activities.
In the brief 25-year history of the College of the Virgin Islands, I'm told there have been only two presidents,
and that Dr. Arthur Richards, the current president, is native-born. The college is part of the land-grant
system-in the 1862 category-and, along with the Experiment Station is performing a valuable service as a
part of the nation's research and education system.
This seems to be a most appropriate time to recognize the importance of agricultural research and education.
Almost 200 years ago President George Washington said: "I know of no pursuit in which more real and impor-
tant services can be rendered to any country, than by improving on its agriculture-its breed of useful
animals--and other branches of a husbandman's cares." We find similar statements by Jefferson, and others
right on through the years.
Today we are aware of the importance of continually training skilled scientists and technicians in the
agricultural sciences so that we can improve production efficiency-bottom line profitability-in agriculture.
We are well aware that we can no longer focus all of our attention on localized problems and situations. We
operate in a worldwide marketplace, and we face reality.
Let's look at some of the things we are doing right now to help meet research and education needs in this im-
portant Caribbean area. Publicly supported agricultural research in the United States' part of the Caribbean is
conducted mainly by the U.S. Department of Agriculture's Science and Education research arm, the
Agricultural Research Service, and the agricultural experiment stations operated by local governments.
Through the Cooperative State Research Service (CSRS)--also one of the Science and Education agencies-
the Department helps support high priority tropical and subtropical agricultural research. This is accomplished
through a Special Research Grants program to agricultural experiment stations in the Caribbean area.
The CSRS Tropical and Subtropical Research Grants are, with your cooperation, helping to solve high priority
research problems that will not only assist the Caribbean area toward becoming more self-sufficient in feeding
itself, but will also have a spill-over effect of assisting other tropical and subtropical areas of the world.
You will recall that tropical and subtropical research is authorized under the Agricultural Trade Assistance
Act of 1966. During the World Food Conference in Rome in 1974, U.S. policy statements made clear that the
United States cannot feed the world, but that it would assist developing countries in strengthening their own
production capabilities.
In keeping with this commitment, we are working together to develop two principal research centers. One
operates in the Western Region and principally involves the Universities of Hawaii and California and the
Guam Agricultural Experiment Station and is known as the Pacific Basin Advisory Group.
Studies on vaccine development for ruminant anaplasmosis and identification and characterization of
geminiviruses occurring in the Caribbean Basin are being made at the Florida Agricultural Experiment Station.
There is a cooperative grant to the Puerto Rico and Florida Agricultural Experiment Stations on improving
tomatoes under high temperature and humidity. These are part of 42 grants totaling $1,490,000 awarded to the
Caribbean area in 1984 by CSRS.
Cooperative Extension programs began in the Virgin Islands in 1972, when the University received land-grant
status. Before that there was a federal extension program. All Extension programs in the area are active-agricul-
ture, natural resources, community and rural development, 4-H, and home economics and human nutrition.
Home gardening continues to grow in popularity because of continued rising costs of food, plus the desire for
fresh, high quality produce. About 200 families planted gardens for the first time last year.
Whole milk is the only agricultural product where supply nearly meets demand on St. Croix and it generates the
largest part of agricultural receipts for the territory. Rangeland constitutes about 75 % of all land now devoted to
agricultural production in the islands. Most rangelands are poorly managed, and Extension is working with pro-
ducers to survey these lands and determine their condition.
Pest management scouting services and training programs have been available in the Islands only a few years.
Local agriculture is rebuilding, and farm enterprises have increased 80% since 1970. Pests typically reduce yield
as much as 35 to 70%. Extension is involved in developing pest management systems.
The National Agricultural Library (NAL) in Beltsville, Maryland, provides many useful services to the Carib-
bean Basin countries. Under a mutually beneficial program, NAL exchanges USDA publications for publica-
tions from institutions in a number of Caribbean countries. As a part of its general international services, it also
provides photocopies of journal articles, and answers reference questions from agriculturalists in these countries.
As a major participant in the FAO-sponsored AGRIS information system, NAL is working with these countries
to build a major international database. Its single most important contact, however, comes in cooperation with
the Agency for International Development (AID).
NAL administers funds from AID to provide a heavy volume of library services, especially current awareness
service and document delivery, to AID missions, individual scientists, and major institutions in the Caribbean,
such as the Caribbean Agricultural Research and Development Institute. We hope you will take advantage of
this agricultural information source.
I hope this brief sketch of the Department of Agriculture's cooperative endeavors in the Caribbean Basin is
enough to whet your appetites to learn more about programs of benefit to us all. And I hope you are convinced
of USDA's keen interest in and sustained support for agriculture in the Caribbean Basin.



Closing Remarks at the CFCS Banquet

October 25, 1984

Alejandro Ayala
Chairman, CFCS Board of Directors

Master of Ceremonies, former Commissioner Henry, Mr. President of CFCS, Lieutenant-
Governor Brady, President Richards, Commissioner Williams, Under-Secretary Bentley, other
members at the head table, ladies and gentlemen: it has been, indeed, a real privilege to share this
extraordinary St. Croix Homecoming Week with all of you. It has been very fitting to celebrate
this Twentieth Annual Meeting of the Caribbean Food Crops Society on this beautiful island.
After all, St. Croix was the cradle of the Caribbean Food Crops Society. We were born here, and
here we are after 21 years, celebrating our coming of age.
Many changes have taken place throughout the Caribbean during this interval. Agricultural
science, in particular, has grown enormously. The potential for increased food production in the
Caribbean Basin has been duly recognized. During this period, our Society has been actively pur-
suing its objectives and has been filling a gap by providing a mutually beneficial interchange of
knowledge, by creating institutional linkages, and by strengthening working relationships among
scientists and agriculturalists who are often isolated. This relative isolation arises mostly from
geographical factors, but also sometimes from differences in culture and language, or because of
financial limitations. The Caribbean Food Crops Society has been, over the years, overcoming
these constraints and creating the needed environment for collaborative efforts.
We can all feel very proud of CFCS achievements throughout the years. The small group that
the late Dr. Richard Bond, Hugh Miller, Arnold Krochmal and others among the founding fathers
gathered together in 1963, has become the core of a truly great professional society, unique in
many ways. The society that they envisioned has grown to productive maturity. I am happy that
some of the founding fathers have been here during this homecoming week to share and enjoy the
harvest of the blessings forthcoming from the seed they planted 21 years ago. They should feel
proud of their achievement. I am particularly happy that we have been able to pay them our
respects and our tribute on this memorable occasion. Those that followed them, and in due time
took over the leadership of the Society, also deserve our recognition. I am happy that President
Padda provided for that since the very inception of this Twentieth Annual Meeting.
A review of the history of CFCS, including the financial constraints under which it has operated,
reveals that reaching this age has required tremendous inputs and insight from some particular in-
dividuals. This reaching of age is, by itself, an amazing achievement. Just looking at the program
of this meeting and at the number and quality of the papers presented, one can assess the substan-
tial and sustained growth and strength of CFCS. More important yet is the recognition that CFCS
has achieved throughout the years: the high regard that it commands and the esteem that it has
earned. In the Caribbean Basin, in Canada, in the United States of America and elsewhere, the
CFCS has indeed earned a valuable reputation. In the years ahead, I expect that as a group, we will
be looking into further opportunities for regional interchange and cooperation. This will involve
technology development and technology transfer and other items stemming from this pool of
talent and resources that is today the Caribbean Food Crops Society.
This may be the best time to publicly and collectively recognize and commend the efforts of one
of our foremost and outstanding Caribbeanists in putting our Society on the front pages, so to
speak. He comes as a gift from ancient, historical India to the Caribbean. He has done wonders, in
a short span of time, with the Agricultural Research and Extension programs at the College of the
Virgin Islands. He has developed, together with President Arthur Richards, a conceptual approach
leading to the more encompassing and broader role of the College of the Virgin Islands in the
Eastern Caribbean. I can assure this man that, at the University of Puerto Rico, we stand ready to
cooperate with him in this task. I can also assure him that CFCS will be ready to provide the re-
quired assistance and support. I am firmly convinced that in his new role as Vice-President of
Research and Land-Grant Programs of the College of the Virgin Islands, he will be able to provide
the leadership necessary to successfully pursue that concept. Ladies and gentlemen, as you realize,
I am referring to our distinguished President, Dr. Darshan Padda.


We might as well take advantage of this opportunity to express our sincere appreciation to Dr.
Padda, to Commissioner Williams, and to all of those in the College and in the Department of
Agriculture who worked so hard in planning and conducting this excellent meeting. I am sure that
all of your agree that it has been a remarkable meeting, with more than 120 papers and a record at-
tendance of 210, including 152 from outside of the U.S. Virgin Islands. A most memorable
meeting, we should call it. It is a fitting celebration of a Twentieth Annual Meeting which at the
same time, involves the elements of homecoming, of really coming back to our roots. And, this is
precisely the way we have been feeling while here: that we are home, at the home of CFCS. We all
have enjoyed not only the meeting as such, but the gracious hospitality of a wonderful people.
May I express, on behalf of the members of CFCS, our appreciation to all of them.
Mr. President, members and guests of CFCS: it has been my privilege to participate in this
meeting and in this banquet. Thank you.




20th Annual Meeting of

the Caribbean Food Crops Society

(Plenary Business Session)
Held at Hotel-on-the-Cay
St. Croix, U.S. Virgin Islands
October 26, 1984

The 20th Annual Meeting of the Caribbean Food Crops Society
(Plenary Business Session) was held at Hotel-on-the-Cay, Chris-
tiansted, St. Croix, October 26, 1984. The meeting was brought
to order by 1983-84 CFCS president Dr. Darshan S. Padda at
11:15 a.m. Minutes of the 19th CFCS Annual Meeting held in
Puerto Rico in September 1983, were presented by Dr. Miguel
Lugo-Lopez, moved for acceptance by M. Alam (Barbados) and
seconded by A. Petersen (St. Croix).
President Padda greeted those assembled and thanked officers
of the CFCS and members for making the meeting such a success
for the 228 persons registered. He pointed out that part of the
success could also be attributed to the flexibility of the organiza-
tion which allowed for changes and adaptations to be made
where necessary. He said there had been many volunteers to host
Annual Meetings in the future.
Secretary Carlos Cruz's report was delivered in his absence by
organizing chairman Walter Knausenberger. Information included:
1. For the first time in years, all Proceedings volumes for re-
cent past meetings are available. Thanks to the assistance
of the College of Agricultural Sciences, University of Puer-
to Rico, three volumes have been published for the 17th,
18th and 19th annual meetings held in Caracas ('81), Bar-
bados ('82) and Mayaguez ('83) respectively.
2. The new constitution has been corrected and retyped in
accordance with the changes made at the business meeting
during the 19th Annual CFCS Meeting in Puerto Rico.
3. The Secretary and Treasurer attended a meeting of the
organizing committee held on St. Croix in February 1984.
It was most helpful.
4. The Secretariat contacted CARDI about serving as 1985 host
for CFCS since it was that organization's 10th anniversary.
5. As a result of a drive by the St. Croix organizing commit-
tee, there were many new members enrolled.
6. Only a single issue of a Newsletter was issued, because the
St. Croix organizers were doing a fine job in keeping the
membership informed.
The Treasurer's Report follows.


August 1, 1983 September 30, 1984

Balance: August 1, 1983

Sale of Proceedings
Sustaining Membership
IICA Contribution
Barbados CFCS Committee

Office Supplies
Secretarial Help
Office Expenses
Contribution to St. Croix
Organizing Committee
Publication of Proceedings
(Venezuela, Barbados,
Puerto Rico)

Balance September 30, 1984






$ 6,517.88



Miquel A. Lugo-Lopez

$ 6,877.66

$ 8,175.44

Patrick N. Williams, the V.I. Commissioner of Agriculture,
served as co-host and vice president of CFCS. After greeting
members, he suggested that the by-laws be amended to include
provision for the election of a president-elect who would also
serve as a board member, to work closely with the incumbent
president, thus giving continuity and stability to the organiza-
tion. Some discussion of the pros and cons followed. No ap-
propriate provision is in the present constitution, and the general
consensus was it should be pursued, but no action was taken.
Dr. St. Claire Forde of Trinidad announced that CARDI has
offered to serve as the 1985 host. This offer was accepted by en-
thusiastic acclamation.
Nominations were received for Board of Directors membership
and officers. The new slate by acclamation comprised the follow-
ing for 1985:
St. Claire Forde, President, Trinidad
Carlos Cruz, Secretary
Miguel Lugo-Lopez, Treasurer
Board of Directors
Darshan S. Padda, Chairman
Alejandro Ayala, Puerto Rico
Ronald Baynes, Barbados
Lucien Degras, Guadeloupe
Freddy Leal, Venezuela
Ivan A. Nicholaas, Aruba
Joseph R. Suah, Jamaica
A special report was delivered by John Cropper (Barbados) on
the Caribbean Agriculture Information Needs special interest
meeting held Tuesday evening, October 23, 1984, attended 45

members of CFCS. The main thrust was the need to improve
interchange of iAformation between countries of the Caribbean.
This interchange would include information on research person-
nel, current information projects of member countries, an up-to-
date bibliography and information outreach to agriculturists.
Working recommendations included:
1. In recognition of the importance of promoting the inter-
change of information between agricultural workers in the
Caribbean, the Caribbean Food Crops Society will prepare
a directory of research workers and their projects as a first
step towards a comprehensive Caribbean Agricultural In-
formation System.
2. The information unit of INRA in Guadeloupe has agreed
to coordinate this activity and to seek financial support for
its completion.
3. We wish to recommend that two volunteers in each coun-
try who are members of the Society undertake the compila-
tion of national directories using a standardized format.
4. The INRA Documentation Center has agreed to collate,
index and distribute the directory to all countries
represented in CFCS.
For the Caribbean Aquaculture Society (whose annual meeting
was held jointly with the CFCS meeting), newly elected president
Andrew S. McGinty thanked members of the plenary business
meeting for the opportunity to meet with CFCS and proposed
that the two societies continue to meet concurrently.
The CFCS gavel, newly prepared by the St. Croix organizers to
commemorate the 20th Annual Meeting, was passed by 1984
president Darshan S. Padda to president St. Claire Forde. The
meeting was adjourned at 12:30 p.m.




Small-Scale Agriculture

in the United States Virgin Islands, 1930-1983

Jerome L. McElroy
Associate Professor of Economics
Saint Mary's College
Notre Dame, IN 46556

Over the past half century, United States Virgin Islands
agriculture has deteriorated because of the phase-out of com-
mercial sugar and escalating resource competition from
tourism, construction, government and export manufactur-
ing. Increasing dualism has resulted with a few large farms
dominating in cattle, dairying, and sorghum, while a very
large number of small (less than 50 acres) farms have increas-
ingly specialized in vegetables, field crops, fruits and nuts,
poultry, and small livestock. Since 1960 these small-scale
holdings have dominated the production of sheep, goats,
hogs, poultry, eggs, avocados, bananas, coconuts, grapefruits,

Klaus de Albuquerque
Research Fellow
Institute of Applied Socio-Economic Research
Papau, New Guinea, and
Associate Professor of Sociology
The College of Charleston
Charleston, SC 29429

limes and lemons, mangoes, oranges, and papayas. In terms of
gross output shares, farms of 3-9 acres have consistently been
the most productive while 10-19 acre farms have been the least
productive. Output per acre comparisons reveal that farm sizes
of under 3 acres and 3-9 acres warrant special policy focus
because of their relatively superior productivity and their ex-
treme.resource constraints.
Keywords: United States Virgin Islands, small-scale
agriculture, modernization, intensive farming, relative pro-

Agriculture in the United States Virgin Islands (USVI), like the
territory's economy, is distinguished by its small scale. Yet, there
is little information available quantitatively detailing the growth
of small-scale farming and its contribution to total agricultural ef-
fort in the territory. In addition, although research conducted
primarily by the College of the Virgin Islands Agricultural Experi-
ment Station has emphasized the small-farm sector (College of
the Virgin Islands, 1980), there is little clear evidence to deter-
mine which small farm size(s) is(are) most efficient and deserving
of special policy attention.
This study is a partial response to some of these deficiencies. It
has three parts. The first presents a contextual overview of USVI
agriculture from 1930 to 1983. The second profiles small-scale
farming in the territory and discusses respective patterns of
specialization. The third examines the relative productivity of the
four smallest-scale farm sizes for policy purposes. In deference to
the United States Census of Agriculture data employed through-
out, we have attempted to keep the conclusions fairly general
because of the dangers of misreporting, the general absence of
written records, and other commonly associated problems/errors.
In addition, we have tried to take some account of small-number
distortions in the data interpretation.

Historical Trends
Since the United States' purchase of the Danish West Indies in
1917, agriculture has steadily deteriorated as a result of the inevi-
table forces of economic modernization. This decline has acceler-
ated especially since 1960 because of the territory's phase-out of
commercial sugar production, intensified resource competition
from tourism, construction, government, and export manufac-
turing, and a widespread pattern of suburbanisation to accom-
modate rising population densities caused by intense immigra-
tion pressures (McElroy and De Albuquerque, 1980). Similar
declines in the face of industrialization have been noted
elsewhere in the Caribbean (Bryden, 1974; Beckford, 1975;
Daubon and Robinson, 1975; Jainrain, 1976; Bourne and Weir,
1980; Hope, 1981; McElroy and De Albuquerque, 1984).


These trends are detailed in Table 1. Since the period during
which the agricultural census is taken is generally July 1 to June
30, sometimes the date of the data (1960, 1975, 1983) cor-
responds to the year following the date of the census (1959, 1974,
1982). The half century since 1930 has witnessed sharp reductions
in total farm acreage, average farm size, harvested cropland, and
agricultural employment. In addition, there have been
measurable declines in agriculture as the main occupation of
farmers as well as predictable increases in the percent of farm
operators engaged primarily (200 + days per year) in off-farm
employment. The data also demonstrate drastic declines in the
use of hired labor, partly as a result of sugar's demise, but also
because of more lucrative job opportunities in tourism, construc-
tion, and so on. For example, both government and tourism
employment rose from roughly 20% of the total in 1960 to 33%
and above 40% respectively in 1982 (McElroy and Tinsley, 1982).
Several rural sector adjustments have taken place during this
long-period encroachment. First has been the increased use of
tractors and fertilizer as substitutes for labor and more traditional
farming and animal husbandry practices (Table 1). A second has
been the noticeable shift away from cropping toward animal
husbandry/poultry-a common Caribbean index of declining ef-
fort and rural marginalization (Richardson, 1983). For example,
the percentage of all farmland in pasture increased from 55% to
77% between 1930 and 1983, while the percent of all farms pur-
chasing livestock/poultry rose from roughly 20 to 70%. Third,
while the percentage of farm operators as owners and on-farm for
ten years increased over the period, the proportion of new farm
operators (2-4 years on farm) steadily declined, indicating
agriculture's waning attractiveness. While the two increases seem
to indicate a growing farming tradition, they may also reflect the
difficulties of selling real estate because of conflicting multiple-
family ownership claims and archaic tenure practices held over
from the Danish colonial period.
The most significant alterations have occurred in farm size and
acreage distributions. Table 2 sketches the broad contours of a
process of growing dualism consisting of an increasing number of


TABLE 1. Selected agricultural indices, U.S. Virgin Islands: 1930, 1960, 1975, 1983.

1930 1960 1975 1983

No. of farms 329 501 327 303
Acreage in farms 68,322 44,062 24,703 20,824
Average farm soze (acres) 207.7 87.9 75.5 68.7
% Agricultural employment 33.2 7.2 0.5 0.5
Harvested cropland (acres) 6,895 4,272 751 819
Harvested cropland/Total acres 10.1 9.7 3.0 3.9
Land in pasture/Total acres 55.31 48.8 62.6 76.8
% Farms with tractors 2.4 6.0 13.1 18.2
% Farms with hired labor 55.3 30.3 33.9 27.7
% Farms purch. livestock/poultry feed 19.1 24.8 67.3 70.0
% Farms using fertilizer 2.4 11.6 19.9 21.8
% Operators with agriculture as main
occupation 67.0 NA 35.5 43.6

% Operators working 200+ days off farm
% Operators who are farm owners
% Operators 10 years or more on farm
% Operators 2-4 years on farm

21.91 46.5 34.3 45.5
44.3 77.0 85.9 80.2

41.6 56.9 58.1


25.61 20.8 17.7 15.5

SOURCES: U.S. Census of the Population for the Virgin Islands, 1930, 1960,
1970, 1980; U.S. Census of Agriculture for the Virgin Islands,
1930, 1959, 1974, 1982. Bureau of the Census, Washington.

very small units juxtaposed alongside a very few large-scale com-
mercial tracts. For example, between 1930 and 1983, the percen-
tage of smallest holdings (under three acres) rose from less than
3 % of all farms to one-quarter of the total. Farms under ten acres
rose from roughly one-third to two-thirds of the total. In 1983,
84% of all farms in the territory were less than 50 acres in size.
On the other hand, the number of large farms-175 acres or
more in the small-island context-fell from one-third of the total
to less than 6%. While acreage in the largest commercial opera-
tions (1000 + acres) grew from one-third to nearly half the total,
the overall acreage contained in the relatively economic medium-
sized farm types (175-259 acres, 260-499 acres, 500-599 acres)
dropped sharply from approximately 60% of the total in 1930 to
31% in 1983.
Table 3 records the impact of these long-run changes on farm
production. The trends indicate the demise of sugar previously
noted and declining significance for cattle, field crops,
vegetables, and some of the more land-intensive fruits/nuts like
coconuts and pineapples. On the other hand, data also show in-
creased output of bananas, avocados, citrus, small livestock,
poultry, and poultry/dairy products. Much of this expansion has
occurred after 1960, a recent agricultural resurgence detailed
elsewhere (De Albuquerque and McElroy, 1983). In summary,
USVI agriculture adapted to a half century of land/labor en-
croachment by contracting farm size and effort, some substitu-
tion of capital inputs, and modifying the composition of output
to suit the constraints of predominantly small-scale holdings and
domestic in contrast to export demand, leaving the largest com-
mercial tracts to further specialize in cattle and dairy products.
Similar changes have occurred throughout many other East
Caribbean islands (Bourne and Weir, 1980).

TABLE 2. Distribution of farm size and acreage, U.S. Virgin Islands: 1930, 1960, 1975, 1983.


1930 1960 1975 1983
Farm Size
% total % total % total % total % total % total % total % total
farms acres farms acres farms acres farms acres

Under 3 2.4 0.1 11.1 0.2 33.3 0.5 24.8 0.6
3-9 34.6 0.8 39.7 2.5 28.7 2.1 37.6 2.9
10-19 10.3 0.7 17.4 2.7 10.7 1.8 10.7 2.0
20-49 10.5 1.5 11.4 4.2 10.1 3.8 11.2 5.0
50-99 4.6 1.4 8.4 6.6 5.8 5.7 5.9 5.7
100-174 4.3 2.8 3.6 5.5 4.0 6.4 4.0 6.9
175-259 8.9 9.6 2.0 4.7 2.1 6.2 1.6 5.4
260-499 11.6 20.2 2.6 10.9 2.4 12.2 2.0 11.0
500-999 8.5 29.3 2.0 15.8 0.9 7.9 1.3 14.7
1000 and over 4.3 33.6 1.8 46.9 1.8 53.3 0.9 45.8

Totall 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Under 10 37.0 0.9 50.8 2.7 62.0 2.6 62.4 3.5
Under 50 57.8 3.1 79.6 9.6 82.8 8.2 84.3 10.5
Under 100 62.4 4.5 88.0 16.2 88.6 13.9 90.2 16.2
175-999 29.0 59.1 6.6 31.4 5.4 26.3 4.9 31.1
175 and over 33.0 92.7 8.4 78.3 7.2 79.6 5.8 76.9

SOURCES: U.S. Census of Agriculture for the Virgin Islands, 1930, 1959, 1974, 1982. Bureau of the
Census, Washington.
May not sum exactly because of rounding error.


TABLE 3. Selected acreage and crop production, U.S. Virgin Islands, 1930, 1960,
1975, 1983.

1930 1960 1975 1983

Sugar cane (acres) 5,823 3,676 4 3
Sorghum (acres) -- 3,531 403
Selected field crops (acres)1 68 98 29 46
Selected vegetables (acres)2 48 32 36 43
Selected fruits/nuts harvested:
Avocados 14,700 37,945 16,561 31,874
Coconuts 27,008 26,107 46,376 18,066
Bananas (bunches) 6,790 20,539 4,785 11,532
Grapefruits (Ibs.) 1,280 1,375 9,750 4,615
Limes/Lemons (Ibs.) 11,640 29,860 35,009 12,472
Oranges (Ibs.) 3,840 3,758 21,055 6,246
Plantains (bunches) 823 401 284 950
Pineapples (boxes) 2,404 1,407 596 74
Mangoes 407,683 173,457 217,807 209,845
Selected Livestock/Poultry
Sheep 1,533 2,152 3,122 2,882
Goats 1,476 2,334 4,162 4,035
Hogs 860 1,297 1,454 2,404
Cattle 12,252 8,383 6,106 5,672
Chickens sold 2,817 3,860 8,669 20,071
Eggs sold (doz.) 4,353 92,050 315,023 284,107
Milk sold (qts.) 494,492 565,781 3,126,063 1,858,145
SOURCE: See Table 2.
lCorn, dry beans, cassava, sweet potatoes, taniers, yams
2Carrots, okra, onions, peppers, egg plant, squash, tomatoes,green beans,

Small-Scale Agriculture
Table 4 provides a review of the impact of this shift from more
extensive to more intensive cultivation patterns orI the four
smallest-scale farm sizes reported in the Census of Agriculture:
under 3 acres, 3-9 acres, 10-19 acres, and 20-49 acres. These data
indicate that the percentage of total acreage in harvested
cropland contained in these small farms increased from 17% of

the total in 1960 to over 60% by 1983. As a consequence, in
terms of the percentage of commercial farms (sales of $2,500),
these four small-holding types dominated the field crops,
vegetable, fruit/nut, and poultry sectors. Between 1960 and
1983-even given the normal caveats associated with interpreting
percentages from very small numbers-under the pressures of en-
croachment and rising inflation, these trends generally inten-
sified with some noticeable differences in sub-specializations. For
example, in 1983 over half of all commercial field crop farmlands
were under 3 acres as were over one-third of all vegetable farms.
In 1983 in addition, 50% of all commercial fruit/nut farms were
3-9 acres in size as were about 80% of all poultry farms. The
other major shift was the dramatic increase in the proportion of
small-scale farm types which together rose from 40% in 1960 to
nearly 75% in 1983.
The above information is helpful in interpreting the differing
small-farm profiles and their respective patterns of resource
utilization assembled in Table 5. First, in contrast to the average-
sized farm of 70-90 acres, these smaller holdings maintained con-
siderably higher acreage shares in cropland and predictably lower
acreage shares in pastures. Their consistently high levels of
woodland/other (roads, buildings, unused lots) is largely due to
the diseconomies of scale associated with their relatively small
sizes. Second, because of their small scale, proportionately fewer
of these small units used tractors and hired labor. These dif-
ferences, however, became less clear in 1983, perhaps partly as
the result of increasing sophistication and modernization as well
as more intensive cultivation of the small-scale specializations in
field crops, vegetables, fruits/nuts and so on.
Third, within the four small-farm classes, increasing scale tends
to be associated as expected with increasing use of tractors, hired
machines, hired labor, rising levels of commercial sales, and fall-
ing levels of part-time (200 + days work off-farm) effort. These
trends reflect not only economies of scale in input utilization,
gradations in farming effort, and perhaps a changing pattern of

TABLE 4. Distribution of harvested acreage and commercial' farms by crop and farm size, U.S. Virgin Islands: 1960, 1975, 1983.

Under 3 ac. 3-9 acres 10-19 acres 20-49 acres TOTAL 0-49 as % of
0-49 acres All Farms All Farms

Harvested cropland (acres)
1960 30 310 222 179 741 4,272 17.3
1975 27 113 61 79 280 751 37.3
1983 53 200 82 174 509 819 62.1
% of total commercial farms:
Crops 1960 6.7(4)2 33.3(20) 21.7(13) 10.0(6) 43 60 64.2
1975 -- -- --
1983 57.1(4) 42.9(3) -- 7 7 100.0

Veg. 1960 16.7(1) 50.0(3) 33.3(2) -- 6 6 100.0
1975 22.2(2) 33.3(3) 22.2(2) 11.1(1) 8 9 88.9
1983 35.7(5) 21.4(3) 21.4(3) 14.3(2) 13 14 92.9

Fruits 1960 15.6(5) 34.4(11) 18.7(6) 25.0(8) 30 32 93.8
& Nuts 1975 29.0(9) 25.8(8) 9.7(3) 9.7(3) 23 31 74.2
1983 25.4(15) 50.8(30) 8.5(5) 6.8(4) 54 59 91.5

Poul. 1960 21.4(3) 21.4(3) 28.6(4) 14.3(2) 12 14 85.7
1975 33.3(6) 11.1(2) 22.2(4) 16.7(3) 15 18 83.3
1983 20.0(1) 80.0(4) -- 5 5 100.0

Live- 1960 8.3(4) 10.4(5) 12.5(6) 8.3(4) 19 48 39.6
stock 1975 15.4(16) 17.3(18) 12.5(13) 14.4(15) 62 104 59.6
1983 17.9(20) 28.3(32) 11.6(13) 15.2(17) 82 112 73.2

SOURCE: See Table 2.
1Commercial farms indicate sales of $2,500 per year.

2Absolute number of farms in parentheses


TABLE 5. Selected characteristics of small farms, U.S. Virgin Islands: 1960, 1975,

Under 3 ac. 3-9 ac. 10-19 ac. 20-49 ac. Fars

Ave. size farm (ac.)
1983 1.6 5.2 13.1 30.3 68.7
1975 1.1 5.5 12.8 28.6 75.5
1960 1.4 5.4 13.6 32.4 87.9
% Acreage in cropland
1983 50.4 41.1 28.0 32.9 8.8
1975 30.6 34.6 22.0 27.6 10.0
1960 39.5 44.2 42.1 30.8 25.7
% Acreage in pasture
1983 18.8 36.5 43.5 49.1 76.6
1975 21.0 35.6 44.0 41.0 62.6
1960 8.6 22.0 32.6 38.7 48.8
% Acreage in woodlands, etc.
1983 30.8 22.4 28.5 18.0 14.6
1975 48.4 29.8 34.0 31.4 27.4
1960 51.9 33.8 25.3 30.4 25.6
% Operators on farm
(2-4 years)
1983 24.0 11.4 12.5 20.6 15.5
1975 24.8 10.6 25.7 15.2 17.7
1960 35.7 17.6 19.5 17.5 20.8
% Operators born in USVI
1983 57.3 64.9 71.9 67.6 66.3
1975 67.9 76.6 60.0 60.6 69.1
1960 69.6 55.3 55.2 49.1 57.5
% Operators working 200 or
more days off farm
1983 53.3 53.5 37.5 35.3 45.5
1975 36.7 31.9 54.3 30.3 34.3
1960 50.0 51.3 35.6 42.1 46.5
% Farms using tractors
1983 5.3 8.8 25.0 29.4 18.2
1975 2.8 5.3 14.3 30.3 13.1
1960 0.0 1.0 1.1 3.5 6.0
% Farms using machines
1983 22.7 37.7 43.8 55.9 39.6
1975 13.8 16.0 11.4 27.3 23.2
1960 12.5 19.6 23.0 24.6 19.4
% Farms hiring labor
1983 12.0 21.1 25.0 44.1 27.7
1975 17.4 29.8 22.9 48.5 33.9
1960 12.5 32.6 29.9 26.3 30.3
% Farms purchasing feed
1983 64.0 66.7 59.4 58.8 70.0
1975 77.1 57.4 51.4 63.6 67.3
1960 25.0 22.1 28.7 22.8 24.8
% Farms purchasing fertilizer
1983 25.3 22.8 18.8 20.6 21.8
1975 11.9 23.4 28.6 24.2 19.9
1960 5.4 8.5 13.8 14.0 11.6
% Commercial farmsl
1903 65.3 68.4 71.9 76.5 71.6
1975 34.9 59.6 54.3 63.6 54.1
1960 30.4 22.6 37.9 38.6 36.3
SOURCE: See Table 2.
1Commercial farms indicate sales of $2,500 per year.

TABLE 6. Distribution of total livestock and poultry production by small farm
size. U.S. Virgin Islands, 1960 and 1983'.

Under 3 acres 3-9 acres 10-19 acres 20-49 acres Total under

S of total cattle
1983 1.5 2.6 1.6 5.6 11.3
1960 0.1 1.0 1.1 2.3 4.5
% of total hogs
1983 22.6 38.4 5.8 9.9 76.7
1960 17.2 25.1 10.8 10.6 46.5
% of total sheep
1983 13.5 15.2 5.3 24.9 58.9
1960 1.1 19.1 6.3 7.3 33.8
% of total goats
1983 13.5 30.3 14.1 17.8 75.7
1960 11.1 20.4 15.8 17.1 64.4
% of total chickens
4 months and over
1983 5.g 88.2 1.5 2.9 98.4
1960 5.9 44.3 13.1 3.8 67.1
% total turkeys and
other poultry
1983 42.6 39.5 7.2 89.3
1960 18.8 32.5 27.4 1.0 79.7
Total eggs sold (doz.)
1983 0.7 99.0 (D)2 (D)2 99.7
1960 1.1 39.7 11.3 0.9 53.0

SOURCE: See Table 2

All figures 3re percentages ocf total territorial trodjction.
2Data rot reporter because disclos.r. t;uid re.l] inr individual farn identification.


specialization toward small livestock, but also some institutional
distortions. For example, the extent of commercial farming (sales
of $2,500) has certainly been affected by inflation. In addition,
the increasing usage of hired machines/custom work may partly
be influenced by the increased availability of subsidized clear-
ing/spraying, etc., services provided by the USVI Department of
Agriculture. Moreover, the comparatively high pasture acreage
share of the two larger small-farm types (10-19 acres and 20-49
acres) may partly reflect merely "running a few goals" to avoid
taxation and reduce the cost of holding land for speculative pur-
poses. Land in the USVI certified as agricultural is eligible for a
95 % property tax exemption and a 90% farm income tax refund.
These measures were implemented to retain land in agriculture
but do not prevent realty speculation since on small farms with
limited farm effort and income "the capital gain that can be
realized is so much larger than the value of the tax break. .. "
(D. Padda, et al. 1978).
Finally, it is noteworthy that the smallest holdings of under 3
acres over the entire period were operated by the highest percen-
tage of young farmers (2-4 years on farm). This can be primarily
explained by the very minimal entry barriers assumed for such
small farms in terms of relatively low startup costs, capital re-
quirements, and labor effort. However, in conjunction with a
sharp decline in the proportion of operators born in the Virgin
Islands recorded only for farms under 3 acres between 1960 and
1983 (Table 5), this uncharacteristically large percentage of young
small farmers may partly reflect the impact of massive West In-
dian migration to the territory during the 1960's tourism and con-
struction boom (De Albuquerque and McElroy, 1982). The
sharply falling levels of new farmers for most all farm classes be-
tween 1960 and 1983 indicate not only the increasing attrac-
tiveness of nonfarm alternatives, but also the consequences of ris-
ing population densities and an accomodative pattern of subur-
ban sprawl on realty values and hence rising entry barriers.

Relative Productivity
Tables 6 and 7 present data on the relative importance of the
small-farm sector in the territory's agricultural economy, and on
the differing productivity of the four small-farm classes.
Although these small-scale holdings contained approximately on-
ly 10% of the total agricultural land, by 1983 they accounted for
the bulk of production in hogs, goats, sheep, chickens, other
poultry, and eggs. In every case, their share of production in-
creased over the 22-year period with the largest gains in hogs,
sheep, and poultry products. By 1983 small farms produced
three-fourths of all hogs and goats in the USVI and over 90% of
poultry products. Regarding fruits/nuts, the data available (1983
only) show that the small-farm sector accounted for 90-95 % of all
limes/lemons and papayas, 80-90% of avocados and oranges,
and 70-75% of all bananas, coconuts and grapefruits.
Within the four small-farm classes, 3-9 acre plots
demonstrated highest shares of total output in hogs, goats,
chickens, and eggs while-again in terms of gross output
shares-20-49 acre units dominated cattle and sheep raising, and
under 3 acre units dominated other poultry (Table 6). The
numerous 3-9 acre holdings, containing over one-third of total
farms in 1983, also dominated the production of fruits/nuts:
specifically avocados, bananas, coconuts, mangoes, and oranges
(Table 7). The 20-49 acre holdings dominated grapefruits and
limes/lemons while plots under 3 acres accounted for the highest
production of papayas. In summary, these data identify the 3-9
acre holdings as the most productive in terms of the gross output
contribution to the insular economy for the limited
livestock/products examined. This is not surprising since such
units contain almost half of the labor (as measured by number of
farm operators) in the small-farm sector and 28% of the acreage

(computed from Table 2). The experience of other Caribbean


islands confirms the production patterns observed above, i.e.,
that small farms account for a majority of the food crop,
vegetable and fruit and nut production (Bourne and Weir,
Determining the relative efficiency of small farms was plagued
not only by census data limitations but also by the unavailability
of acceptable local estimates for allocating acreage to specific
crops and livestock rearing in the highly mixed intercropping
systems characteristic of the USVI. These factors precluded the
utilization of more sophisticated efficiency criteria commonly
employed elsewhere to assess productivity in mixed farming (Har-
wood, 1979). As a result, two crude measures were constructed:
output and/or livestock per acre and output per tree of bearing
Tables 8 and 9 present the results. In the first case, relative effi-
ciency was estimated for 1983 by dividing the total output pro-
duced by each farm size for each fruit/nut selection by the respec-
tive acreages in fruit/nut production for each farm size classifica-
tion. According to this method, the smallest scale of under 3 acres
was most efficient, achieving the highest production per acre in
every fruit/nut category. A similar analysis of livestock productiv-
ity-total number of sheep/goats/hogs/cattle divided by total
acreage in pasture and grazing land-generated similar results.
With the exception of bananas, coconuts, and grapefruits, 3-9
acre holdings were second in efficiency. However, although these
findings do capture the intensity of effort on the two smallest-
scale classifications, they should be accepted guardedly because of
the aggregative nature of the methodology, which ignores inter-
cropping patterns and variations in land quality, and because of
the assumption of constant output quality, especially with respect
to livestock, across farm size categories.
In the second experiment, the ratios of harvested fruit/nut
production to respective trees/hills of bearing age were calculated
for each farm size for only two years for which census data were
available, 1975 and 1983. Although the figures in Table 9 in-
dicate some large productivity differences for the same farm sizes
across the two years-perhaps due to topographical variations,
tree stock maturity differentials, and/or the vagaries of
weather-the overall results generally suggest that sizes of under
3 acres and 20-49 acres were relatively most efficient in non-citrus
and citrus products respectively, while units of 10-19 acres were,
with some exceptions, least efficient.

In summary, these analyses of relative productivity, confined
by the limitations of crop selection imposed by census data, sug-
gest that in terms of gross output contributions to the territorial
economy farms of 3-9 acres were generally superior in small
livestock and non-citrus fruit/nut production while farms of
20-49 acres were superior basically in citrus produce and sheep
and cattle. In terms of relative efficiency or production per acre
and per tree/hill of bearing age, farms of under 3 acres were most
efficient across all tests with differentials clearest in non-citrus
fruit/nut products while farms of 20-49 acres demonstrated their
comparative advantage in citrus. In all cases, farms of 10-19 acres
scored the lowest performance.
Such findings should assist policy-makers in view of:
1. The resource constraints that circumscribe such efforts and
call for prioritizing;
2. Escalating USVI food imports which have risen from $5
million in 1960 to over $80 million presently (Government
of the Virgin Islands, 1980:26);
3. The long period of USVI agricultural decline; and
4. The common problems infesting agriculture here and
elsewhere in the region (Belisle 1983).

However, because of the rudimentary nature of the analysis and
numerous data gaps, the primary implication of the study is to


TABLE 7. Distribution of selected fruits/nuts production by small-farm size. U.S.
Virgin Islands, 1982.

Under 3 ac. 3-9 ac. 10-19 ac. 20-49 ac. Total

% Avocados 21.7 35.3 9.3 21.9 88.2
% Bananas (bunches) 17.1 29.5 17.0 6.1 69.7
% Coconuts 10.7 24.0 12.4 22.9 70.0
% Grapefruits (Ibs.) 17.3 16.0 10.0 32.6 75.9
% Limes/Lemons (Ibs.) 23.3 25.6 7.9 38.1 94.9
% Mangoes 8.9 25.8 5.0 17.1 56.8
% Oranges (Ibs.) 11.6 37.9 3.5 28.4 81.4
% Papayas (Ibs.) 33.1 30.1 11.8 18.6 93.6

SOURCE: U.S. Census of Agriculture for the Virgin Islands, 1982. Bureau
of the Census, Washington.

TABLE 8. Selected fruits/nuts and livestock per acre by small farm size. U.S.
Virgin Islands, 1983.

Under 3 ac. 3-9 ac. 10-19 ac. 20-49 ac.
Total acres in
fruits/nuts 38 170 65 148
Output per acre:
Avocados 182 66 46 47
Bananas (bunches) 52 20 30 5
Coconuts 51 26 34 28
Grapefruits (Ibs.) 21 4 7 10
Limes/lemons (Ibs.) 77 19 15 32
Mangoes 492 319 160 243
Oranges (Ibs.) 19 14 13 12
Papayas 42 9 9 6
Total acres in pasture
and grazing land 22 217 182 506
Total cattle, sheep,
goats, and hogs 1,564 2,735 952 1,995
Total livestock per acre 71 13 5 4

SOURCE: See Table 7.

TABLE 9. Ratios of harvested output to trees of bearing age for selected
fruits/nuts. U.S. Virgin Islands, 1975 and 1983.

Under 3 acres 3-9 acres 10-19 acres 20-49 acres

1983 29.0 22.3 17.4 44.8
1975 38.7 14.8 25.9 12.1
Bananas (bunches)
1983 0.55 0.44 0.16 0.38
1975 0.70 0.54 0.43 1.29
1983 9.4 10.3 3.7 5.4
1975 22.8 10.4 7.5 7.8
Grapefruits (Ibs.)
1983 22.2 10.3 4.9 31.3
1975 7.1e 2.3 7.9 10.7
Limes/Lemons (lbs.)
1983 12.0 7.3 8.9 22.4
1975 24.6 15.4 13.5 25.0
1983 82.0 47.7 34.6 94.4
1975 61.4 66.0 19.4 8.7
Oranges (lbs.)
1983 12.3 15.0 8.8 15.0
1975 7.1 7.8 2.6 10.5
1983 8.6 2.7 2.2 7.8
1975 8.5 4.5 5.4 3.4

SOURCES: U.S. Census of Agriculture for the Virgin Islands, 1974 and 1982.
Bureau of the Census, Washington.

clearly point up the general need for more serious survey research
to uncover actual small-scale mixed cropping patterns, ad-
justments to constraints, levels of farm effort and productivity,
and so on (W. Shaner et al., 1982). In particular, these findings
suggest that the two smallest scale farm classifications deserve fur-
ther scrutiny not only because of their relatively superior efficien-

cy and output performance, but also because one of the most
glaring deficiencies identified in the territory is the existence of
large tracts of "essentially semi-abandoned" agricultural land
(Government of the Virgin Islands, 1980:61) highly suitable for
the kinds of intensive small-farm crop cultivation documented

1. Beckford, G. 1975. Caribbean rural economy. Caribbean Economy. In-
stitute of Social and Economic Research, Kingston,Jamaica. pp. 77-91.
2. Belisle, F. 1983. Tourism and food production in the Caribbean. Ann.
Tour. Res. 10:497-513.
3. Bourne, C., and C.C. Weir. 1980. Overview of small farming in the LDC's.
Small Farming in the Less Developed Countries of the Commonwealth Caribbean.
Caribbean Development Bank, pp. 312-326.
4. Bryden,J. 1974. Impact of the tourist industries on the agricultural sectors:
the competition for resources and food demand aspects. Proc. 9th W.I. Agric. Conf.
pp. 153-161.
5. College of the Virgin Islands. 1981. 1980 Annual Report: Agricultural Ex-
periment Station, Cooperative Extension Service. St. Croix, USVI.
6. Daubon, R. and W. Robinson. 1975. Changes in consumption patterns
during economic development: Puerto Rico, 1940-1970. Soc. and Econ. Studs.
7. De Albuquerque, K., andJ. McElroy. 1982. West Indian migration to the
U.S. Virgin Islands. Intnl. Migr. Rev. 16(1):61-101.
8. 1983. Agricultural resurgence in the U.S. Virgin Islands. Carib.
Geog. 1(2):121-132.
9. Government of the Virgin Islands. 1980. Policy guidelines for the develop-
ment of agriculture. USVI Dept. of Agriculture, St. Thomas, USVI.
10. Harwood, R. 1979. Small farm development: Understanding and improv-
ing farming systems in the humid tropics. Westview Press, Boulder, CO.

11. Hope, K. 1981. Agriculture and economic development in the Caribbean.
Food Policy 6(4):253-265.
12. Jainrain, I. 1976. Trade and underdevelopment: A study of small Carib-
bean countries and large multinational corporations. Institute of Development
Studies, Georgetown, Guyana.
13. McElroy,J., and K. De Albuquerque. 1980. Residential patterns in the U.S.
Virgin Islands. So. Atl. Urban Studs. 5:287-306.
14. 1984. The British Colonies, in J. Hopkins (ed.) Latin America
and Caribbean Contemporary Record III:1983-1984. Holmes & Meier, New York
15. McElroy,J., andJ. Tinsley. 1982. The U.S. Virgin Islands, in S. Seward and
B. Spinrad (eds.), Tourism in the Caribbean: The Economic Impact. International
Development Research Centre, Ottawa, Canada, pp. 23-65.
16. Padda, D. 1978. Virgin Islands agricultural development study. College of
the Virgin Islands, St. Croix, USVI (Mimeo).
17. Richardson, B. 1983. Caribbean migrants: Environment and human sur-
vival on St. Kitts and Nevis. University of Tennessee, Knoxville.
18. Shaner, W., P. Philipp, and W. Schmehl. 1982. Farming systems research
and development: Guidelines for developing countries. Westview Press, Boulder,
19. United States Department of Commerce. (Various years.) U.S. Census of
the population for the U.S. Virgin Islands. Bureau of the Census, Washington, DC.
20. United States Department of Commerce. (Various years.) U.S. census of
agriculture for the U.S. Virgin Islands. Bureau of the Census, Washington, DC.



The Decline of Agriculture

and Projection of the Number of Farm Units

in the United States Virgin Islands

Frank L. Mills
College of the Virgin Islands

The collapse of the sugar industry in the Virgin Islands in
1966 ushered in a period of decline in agriculture which has
persisted till the present. Despite the government's efforts to
increase production, the agrarian domain has been under
relentless siege by competing industrial, commercial and social
interests. The paper is presented in three sections. The first
gives, and discusses, basic quantitative parameters of the
decline in agriculture over the last 20 years. The second makes
use of a stochastic model-absorbing Markov chains-to pro-
ject the decline in the distribution and the total number of

There is hardly any doubt that in the minds of the majority of
the residents of the Virgin Islands, agricultural activity should
constitute one of the major components of the economy of the
territory. Until the recent past, i.e., about twenty years ago, most
native Virgin Islanders had known little more than the
monoculture of sugar cane that had dominated the economy
from colonial days. And for many other residents of the Carib-
bean, agriculture had always featured prominently in their island
economies. The period that begins about 1960 can be described
as a watershed in agricultural production in the Virgin Islands,
for despite recent efforts to restore agrarian-based activities to a
higher level than it has been in the last decade, there appear to be
signs of an irreversible trend to a decreasing role for agriculture.
This tendency to a reduced performance of agriculture can be
broadly ascribed to three initial and interrelated factors: the col-
lapse of the sugar industry in 1966, the impact of tourism and
heavy industry, the population pressure on limited space.
The Virgin Islands Company (VICO) that was created by the
Federal Government in 1934 was done with the express purpose
of stimulating the economy by the operation of a sugar, rum and
hotel business. Its successor in 1949 was the Virgin Islands Cor-
poration (VICORP), which the Congress prohibited from any fur-
ther production of rum. The production of sugar proved to be
unprofitable, and VICORP sold off or conveyed its assets to the
local government. This ensured the demise of the sugar industry
in 1966. The early 1960s was marked by a rapid increase in
tourism, and many hotels and tourist recreation facilities were
built on land that was previously in the agricultural domain, in-
cluding an 18-hold golf course and a condominium complex in
St. Thomas, and two golf courses in St. Croix. The net result was
that many agricultural workers drifted into the tourist industry as
unskilled workers, and the demand for more cheap labor per-
sisted for more than a decade.
The supply of labor for the increasing number of tourist
facilities and for the burgeoning construction industry was met
largely through migrant labor from the Eastern Caribbean and
from the U.S. mainland. The demand for housing grew concomi-
tantly, and inroads into abandoned rural farm land or


farm units over the next 20 years. The third section details
those causative factors that may explain the decreasing perfor-
mance in agriculture. These latter include the impact of the
abandonment of sugar production, the development of
tourism, the increase in industrial and commercial activities,
competition from imported foodstuffs, the policies of govern-
ment, the unavailability of land, the lack of trained personnel,
the shortage of labor, inadequate supplies of water, and insuf-
ficient marketing facilities. The paper concludes with a call for
a conscious policy commitment by the government.

agricultural lands adjacent to urban areas were readily given over
to public housing complexes and other expressions of residential
housing needs.
Hence it is quite clear that agrarian land has been under persis-
tent siege by competing commercial and social interests, and this
continues to be the case in the mid-1980s. The objective of this
work is, therefore, to explore two issues. The first is an examina-
tion of the major characteristics of farming in the territory
through an analysis of agricultural census data. The second is a
projection of the number of farming units in five-year periods till
the year 2000. The approach that is taken below is to discuss,
first, some of the attributes of Virgin Islands agriculture which
will lay the groundwork for the succeeding section. The second
step is to present the salient features of the stochastic model- ab-
sorbing Markov chains-that is used in the projection of the
distribution of farm units. After a presentation of the future pat-
tern of decline, an attempt will be made to provide reasonable
answers to why farming is on a continual decline in the Virgin

Attributes of Virgin Islands Agriculture
The most appropriate point of departure for a discussion of
recent performance in agriculture appears to be the hiatus in ac-
tivity of the early 1960s. Prior to that time, sugar and cotton pro-
duction, raising livestock, and truck farming were the primary
enterprises in farming, with the latter confined principally to St.
Thomas. The artificially sound VICORP collapsed when it could
no longer produce rum, and thus the sugar industry was the ma-
jor casualty in 1966. This, therefore, led to the abandonment of
large tracts of agricultural land and the retirement from this in-
dustry of hundreds of acres of prime land. The evidence for this
may be seen in the Census of Agriculture data for 1960 and 1970,
which show not only a decrease in the number of farms, but also
in the number of acres that remained productive. The 1982 Cen-
sus of Agriculture in the Virgin Islands defines a 'farm' "as a
'place' of three acres or more on which any field or forage crops
were harvested or vegetables were harvested for sale during the
12-month period between July 1, 1982 and June 30, 1983, or on


TABLE 1. Selected characteristics of Virgin Islands farming: 1960 to 1982.

Farm Units
Produc- Z Farms
Growth tive Producing
Year No. Z Change Factor Acreage for Sale

1960 501 44062 60.3
1964 466 -7.0 0.93 39539 49.1
1970 212 -54.5 0.45 20470 48.6
1975 327 54.2 1.54 24703 54.1
1978 378 15.6 1.16 24397 46.6
1982 303 -19.8 0.80 20824 71.6

rate of
change -10.6% -9.6% -16,2%

Note. The data in column 2 are respectively from the U.S.
Census of Agriculture, Virgin Islands of the United States,
U.S. Bureau of the Census.

which there was a combined total of ten or more fruit or nut trees
or plants, any livestock, or ten or more poultry at the time of
enumeration. Places of less than three acres were counted as farms
if their sales of agricultural products amounted to at least
$100, or if they could normally be expected to produce
agricultural products in sufficient quantity to provide sales
amounting to at least $100 ... The definition of a farm for 1982
was the same as in all previous census, except the one for 1950"
(U.S. Bureau of the Census, 1983, p. iv). In fact, Table 1 shows
that the total number of farms in 1964, 466, was reduced to less
than half in 1970 when only 212 remained. And concomitantly,
the total productive acreage recorded the largest decline in the
last 25 years, a change of 52.7% or a growth factor of 0.473.
The pattern of change that is reflected by the data of Table 1 is
one of decline, but this has not been consistent from one quin-
quennium to the next. First, it is noted that overall there is a
10.6% rate of decrease per period between 1960 and 1982, in the
number of farm units in the territory. The table also shows that
the decline has not been constant: the third and fourth columns
of percent changes and growth factors respectively express uneven
rates of decrease and increase. The average period-to-period per-
cent change is therefore 9.6%. The acreage devoted to farming
is related to the number of units under production, and the data
thus reflect the same type of increase and decrease. Overall, the
average rate of decrease between periods is 16.2%.
The most recent census records the largest percentage since
1960 of the total number of farms that produce for sale, versus
those that produce for home consumption only. Whereas about
six out of ten farms were producing for sale in 1960, the rate in
1982 was seven out of ten.

Census documents group most of the farm data by size
categories. It is therefore useful to examine, by comparison, the
frequency distributions of the last five quinquennial censuses to
determine if the number of farm units in each of the categories
remains basically the same from one census year to the next, or if
they increase or decrease. The last decennial census of agriculture
in the Virgin Islands was taken in 1960. The first quinquennial
census of agriculture was taken in 1964. For the 1969 quinquen-
nial census, the data were collected in 1970 to coincide with the
decennial Census of Population and Housing. In 1976 Congress
authorized censuses for 1978 and 1982 "to adjust the data
reference year to coincide with the 1982 Economic Censuses .
after 1982, the agriculture census will revert to a 5-year cycle"
(U.S. Bureau of the Census, 1983, p. iv.). The data in Table 2 il-
lustrate that, whereas the percentages of the number of farms

TABLE 2. Percentage of Virgin Islands farms by size: 1964 to 1982.

Size of farms
(in acres) 1964 1970 1975 1978 1982

Less than 3 10.3 31.1 33.3 24.1 24.8
3 to 9 42.0 25.9 28.8 38.9 37.6
10 to 19 16.1 11.3 10.7 14.3 10.6
20 to 49 10.5 11.8 10.1 9.0 11.2
50 to 99 6.8 7.6 5.8 5.0 5.9
100 to 174 5.2 3.3 4.0 2.1 4.0
175 to 259 2.2 1.4 2.1 2.1 1.6
260 to 499 3.0 3.3 2.5 2.4 2.0
500 to 999 2.4 1.9 0.9 0.8 1.3
1000 or over 1.5 2.4 1.8 1.3 1.0

100.0% 100.0% 100.0% 100.0% 100.0%
(466) (212) (327) (378) (303)

over 100 acres in size have remained rather constant, the numbers
in the smallest category (of less than three acres) have varied
remarkably. Among the number of farms over 1,000 acres, there
were 1.5% in 1964, and 1.0% in 1982. In 1964, 10.3% of the
farms were less than three acres in size, and this number tripled
to 31.1% by 1970. The largest percent of 33.3 was recorded in
1975, and the most recent count listed 24.8%. No other category
registered this degree of variation in the proportion of farms in
intercensal periods. The large increases between 1964 and 1975
may probably be explained by the dismemberment of some of
the sugar plantations that ceased sugar cane production in 1966.
It was of further interest to examine the five distributions to
determine statistically if it can reasonably be said that, basically,
the same distribution of the percentage of farms was maintained
in each of the census years from 1964-1982. The chi-square test of
homogeneity is utilized to establish if the differences between the
distributions can be ascribed to a chance process. The validity of a
statistical test of significance on population data may have crossed
the reader's mind. However, the attempt is not to generalize here
to a larger population; it is merely to rule out the 'chance process'
alternative as an explanation for the observed differences. See
Blalock (1979, p. 242). The computed chi-square and associated
probability of p = .00011 suggest that the populations are
neither identical nor homogeneous, and that chance is not
responsible for the observed differences. In fact, the test confirms
that the largest differences are between 1964 and 1970, and these
may be attributed to the agrarian change in sugar production that
characterized the period.
Commensurate with the decline in farm unit numbers was a
decrease in the number of acres devoted to productive
agricultural practices. Table 1 recorded a quinquennial decrease
of 16.2% over the period, and Table 3 illustrates the percentage
of agrarian land that was distributed among the various size
categories. Typical of most farming systems throughout the
Caribbean, less than 1% of the total farm acreage in 1982 was
found on 25 % of the farms under three acres, and for most years,
more than half of the total agrarian land was confined to farms
over 1,000 acres in size. While the percentage of the acreage on
farms of less than three acres tripled from 1964 to 1970, i.e., from
0.2% to 0.6%, the actual amounts were 69 (1964) and 117 acres
(1982). However, the percentage in almost all categories from 3
to 999 acres decreased between 1964 and 1970. The category that
registered an increase was farms over 1000 acres: from 39.2% in
1964 to 54.7% in 1970. The last census marks the first time in
about 15 years that the percentage of farms in the largest category
is less than 50%, 45.7% in fact.



TABLE 3. Percent distribution of Virgin Islands farms by acreage: 1964 to 1982.

Size of farms
(in acres) 1964 1970 1975 1978 1982

Less than 3 0.2 0.4 0.5 0.5 0.6
3 to 9 2.6 1.3 2.1 3.0 2.9
10 to 19 2.5 1.4 1.8 2.8 2.0
20 to 49 3.8 4.0 3.8 4.4 5.0
50 to 99 5.7 5.3 5.7 5.4 5.7
100 to 174 8.0 4.1 6.4 3.8 6.9
175 to 259 5.3 3.0 6.2 7.1 5.4
260 to 499 13.1 12.7 12.3 12.8 11.1
500 to 999 19.6 13.1 7.9 8.8 14.7
1000 or over 39.2 54.7 53.3 51.4 45.7
100.0% 100.0% 100.0% 100.0% 100.0%
(39539) (20470) (24703) (24397) (20824)

A chi-square test of homogeneity was conducted on the
distributions (of the actual number of acreages) to determine if
the population remained homogeneous throughout. The large
chi-square value produced an associated p less than .0000. One is
fairly certain that the distrubtions have changed substantially
over time. The computed adjusted residuals, however, suggests
that factors other than the abandonment of sugar production in
1966 may have been responsible for the departures from
homogeneity in the system.
It was also of interest to examine the distribution of farm
operators by age group, since with the public financial support
for young farmers in recent years, one would normally expect the
youthful age groups to reflect these entrants. A 'farm operator' is
defined as a "person who operates a farm, either by doing the
work himself/herself or by directly supervising the work. The
operator may be the owner, a member of the owner's household,
a hired manager, or a tenant, renter, or sharecropper .. ." (U.S.
Bureau of the Census, 1983, p. A-1). First, however, Table 4
reflects that, since 1969, the average age of farm operators is
becoming older, not younger. There does not appear to be any
substantial movement of youth into farming, and it is to be
observed from the table that the percentage of operators over 55
has increased since 1974.
In order to test further the supposition that the age structure of
recent years should reflect a change from that of the past, the
populations of the last five censuses were tested by a chi-square
test of homogeneity to establish if the differences between the
observed distributions were due to chance. The computed chi-
square and associated probability (p = .293) lend strong evidence
that there is no substantive departure from homogeneity of the age
structure over time, and that the differences observed are most like-
ly due to a chance process. This outcome was indeed surprising,
and a possible explanation is explored later in the paper.
A final attribute of the farming pattern is the number of farms
that have been recorded which produce for home consumption,
and those which produce for sale. The last column in Table 1 in-
dicates that there is no real constancy in the proportion of sale
holdings, but it does appear extraordinary that over the years no
more than about two out of three holdings are devoted to pro-
duction for sale, or that more than one-third of the designated
farm units produce for home consumption only.
Thus, the major factors that characterize farming in the Virgin
Islands present clear evidence that the overall industry is in a state
of decline, both in terms of the total number of acres devoted to
productive agriculture, and the number of farm units involved in
this production. The following section is therefore given over to a

TABLE 4. Percent distribution of Virgin Islands farms by age group: 1964 to,1982.

Age group 1964 1970 1975 1978 1982
Less than 25 0.7 0.9 2.1 1.1 2.0
25 to 34 6.1 9.4 6.1 6.3 4.0
35 to 44 19.3 22.6 16.5 19.0 18.2
45 to 54 28.2 20.3 25.4 22.0 22.8
55 to 64 25.0 27.9 27.0 28.1 28.6
65 and over 20.7 18.9 22.9 23.5 24.4
100.0% 100.0% 100.0% 100.0% 100.0%
(466) (212) (327) (378) (303)

Average age 53.5 51.8 52.4 54.0 55.0
Note. Base data derived respectively from the U.S.
Census of Arriculture. Virgin Islands of the United
States, U.S. Bureau of the Census.

discussion of the Markov chain model used in the projection of the
total number, and distribution, of farm units in the years ahead.

Projection of Future Size Distributions

Basic Elements of the Markov Chain Process
The areal organization of functional units through time, and
the paths they are likely to follow in future time periods, have
often arrested the interest of the geographer, be they units of
settlement, industry, or farms (Collins et al., 1974; and Collins,
1975). In a similar vein, agricultural economists share a common
interest, as is evident from the works of Judge and Swanson
(1961), Dovring (1962), and Krenz (1964). The application of
the Markov chain model to spatially distributed time-varying data
is contingent on the definition of a set of mutually exclusive states
or categories which comprise the total distribution and the area
under study. It also assumes that movements of units between
states over time can be considered as a stochastic process, i.e., in
any given sequence of events, the outcome of each movement
depends on chance. The process can be in only one state at a
given time and it moves successively from one state to another.
And the probability that the process moves from S, to Sj depends
only on the state S, that it occupied before the move. For com-
plete details on the estimation of the fundamental matrix and
related statistics, see Kemeny and Snell (1976, pp. 43-50).
The states used in this study are the classifications used by the
Bureau of the Census:


Size of farm (acres)

S, ................... .............Less than 3
S2 ............... ................. 3 to 9
S3 .............................. l10 to 19
S4 ............................... 20 to 49
Ss ............................. 50 to 99
S6 ........................... 100 to 174
S7 ........................ ...... 175 to 259
Ss ............... .. ........ 260 to 499
S9 ................................ 500 to 999
SIo ........................... 1000 or over

Within a given set of states, it is generally possible to estimate
the probabilities (p,) of observations moving from one state to
another. Such probabilities of movements for a given time period
can be summarized in a transition matrix, the elements of which
denote the probability of moving from state S, to Sj in the next



TABLE 5. Estimated transition probabilities of farms from 1978 to 1982.

States S S S S S S 8 S S S S
0 1 2 3 4 5 6 7 8 9 10
S 1 0 0 0 0 0 0 0 0 0 0
S .176 .824 0 0 0 0 0 0 0 0 0
S .224 0 .776 0 0 0 0 0 0 0 0
S .352 0 0 .593 .055 0 0 0 0 0 0
S 0 0 0 0 .912 .088 0 0 0 0 0
S 0 0 0 0 0 .790 .210 0 0 0 0
8 0 0 0 0 0 0 1 0 0 0 0
8 .250 0 0 0 0 0 0 .625 .125 0 0
S .333 0 0 0 0 0 0 0 .556 .111 0
S 0 0 0 0 0 0 0 0 0 1 0
S .400 0 0 0 0 0 0 0 0 0 .600

step. The transition matrix, in addition to the initial starting
state, completely defines the Markov process; i.e., with the
foregoing information, it is possible to determine the outcome of
the process at the n'h step.

Estimation of the Transition Matrix
The efficient estimation of transition probabilities often
presents a major technical problem because such estimates de-
pend on the quality of the data available. However, three alter-
native approaches are possible: statistical estimation from micro-
unit data, from aggregate data, and from conceptual considera-
tions (Collins et al., 1974). This study, following Krenz (1964),
adopts a conceptual approach to the estimation of transition pro-
babilities. The Bureau of the Census does not provide data on in-
dividual farm units in the quinquennial censuses, and only
enumerates farms in one of the several categories given above. By
making use of detailed information on the life of farms in the
Virgin Islands, patterns of behavior are assumed and rules subse-
quently adopted in order to determine the transition pro-
babilities. In this regard, the following assumptions are made.

First, it is presumed that most farm operators in the Virgin
Islands would want to expand their acreage if it is possible to do
so. Second, it is more likely that medium to average size farms
will expand because of financial resources available, and because
of economies of scale, than it is that small farm units will increase
their acreage. Third, any increase in farm size is likely to proceed
gradually by the acquisition of adjacent property. Such incremen-
tal aggregation is likely to be a function of the availability of
agriculturally zoned land, and of reasonable financial ar-
rangements for purchasing land. Fourth, individual farms are not
likely to decrease their unit size voluntarily, particularly because
of the problems of economies of scale. Rather, it is more probable
that a farm will go out of business than exist as a reduced entity.
It is on the basis of these assumptions that the following two rules
are adopted in determining the transition of farms from one state
to another.
An increase in the number of farms in any state S;, from one
time period to the next, comes from the next smaller state, Si-. A
decrease in the number of farms in any state indicates a move-
ment to So, a state of demise. The application of these rules of
behavior to the data at hand produces the transition matrix that is
utilized below. One advantage of the transition matrix is that it
provides useful insights into the movements of farms that are not
readily available from other types of projection models.


TABLE 6. The fundamental matrix of mean five-year periods

The Application of Absorbing Chains
In the movement of farms between states discussed above, it
was indicated that states So is that state in which all farms that go
out of business eventually end up, and the assumption was that
they remain there. Such a state in a Markov chain is defined as an
absorbing state if it is impossible to leave it. A chain is therefore
absorbing if it has at least one absorbing state and from every
state it is possible to go to an absorbing state (Kemeny et al.,
1962). With one absorbing state in this study, that of going out
of business, the model employed here is an absorbing Markov
chain. The application of the theory of absorbing Markov chains
thus permits one to generate very useful answers to a number of
questions (Kemeny et al., 1962; Bartholomew, 1982).
First, what percentage of farms that are in a given state S, (or
size category) are likely to be amalgamated with farms in a larger
size category Sj after five years? This question can be answered by
examining the coefficients of the transition matrix. Second, for
any farm of a particular size, how long is it likely to stay within its
size classification before it amalgamates with another? Such a
question can be answered from the elements of a fundamental
matrix. Thus, the coefficients of this matrix give the mean
number of years (of five-year duration) in each transient state for
each possible nonabsorbing starting state.
Third, on average, how long does it take before a farm in a
given size category is absorbed or goes out of business? The sum
of all the entries in a row of the fundamental matrix will give the
total length of (five-year) time periods that a farm is likely to sur-
vive before going out of business. Fourth, what, in absolute
numbers, is the distribution of farms, according to size
categories, likely to be in five years, in ten years, or in n years?
Or, how many farms in total will there be in five, ten, or n years?
Of the two alternative methods for projecting these numbers, use
is made of that which multiplies the distribution of farms in the
base year, 1978, by the canonical form of the transition matrix P
to generate the projected distribution for one period; then the
result is postmultiplied by P for the needed number of periods
(Krenz 1964). For complete details on the estimation of the fun-
damental matrix and related statistics, see Kemeny and Snell
(1976, pp. 43-50).

Empirical Results
The frequencies used to estimate the transition matrix were
derived from the census data of 1978 and 1982, and by the ap-
plication of the rules stated previously. The particular quality of
the Virgin Islands census data dictated that only the data for 1978
and 1982 could be utilized in the generation of the transition


TABLE 7. Projected numbers and distributions of farms, with 1978
as the transition base.

Year S S S S S S S S S S Total cline
1 2 3 4 5 6 7 8 9 10
1978 91 147 54 34 19 8 8 9 3 5 378
1982 75 114 32 34 18 12 5 6 4 3 303 75

1987 62 88 19 33 17 16 3 4 5 2 249 54
1992 51 69 11 31 16 19 2 3 5 1 208 41
1997 42 52 7 29 16 23 1 2 5 1 178 30
2002 35 40 4 27 15 26 1 1 6 0 155 23
Note. Data for 1978 and 1982 are actual census data and
are included for comparative purposes.

matrix. This in itself is statistically acceptable since the theory in-
dicates that the outcome or form of a given distribution-that of
1982, say-is dependent only on the outcome or distribution of
the immediately preceding one-that of 1978-and that the
dependence is the same at all stages (see Judge and Swanson,
1961, p. 2). The transition probabilities shown in Table 5 permit
certain insights into the dynamics of farm movements in the
Virgin Islands. The matrix reflects many zero elements, an ob-
vious indication of the lack of data on individual farms from one
category to another.

Row So suggests that no new farms have been entering farming,
according to the assumptions above, and column So, an absorbing
state, reveals that from all categories except S4, Ss, S6. and S9
farms are going out of business. The principal diagonal contains
relatively large coefficients, which tend to indicate a degree of
stability in farm size. The nonzero elements in row S1 signify that
approximately 18% of the farms of less than three acres go out of
farming in any five-year period. Of this same group, about 82%
will remain in the same size category. Similarly, about 35% of
the farms in S3 (10 to 19 acres) are likely to go out of business in a
five-year period, about 59% are likely to stay in the same size
group, and about 6% are likely to amalgamate with farms in S4
(20 to 49 acres). None of the farms in S4, Ss and S6, between 20 to
174 acres, is likely to go out of business; in fact, farms in S, show
total stability. In addition, all farms between 20 and 500 acres
show tendencies to expand (with the exception of those in S6).
On the contrary, the largest farms exhibit the greatest inclination
to founder: four out of ten farms over 1,000 acres are likely to fail
in any five-year period.

The elements of the fundamental matrix permit additional in-
sights into the behavior patterns of farms: they give the mean
number of five-year periods in each size category before going out
of business, depending on the starting state. Thus, in Table 6,
row S, indicates that the mean number of years for a farm of less
than three acres to exist before going out of business is about 28
(5.69 x 5) years. Similarly, it is about 22 years that farms be-
tween 3 and 10 acres will exist before their demise. For farms be-
tween 10 and 20 acres, however, the length of time they are likely
to stay in that size category is 12 years before being amalgamated
with a larger farm. In its higher size classification, it is likely to
stay there for about eight years before amalgamating again, and
so on. Thus, the total length of time a farm operation is likely to
stay in a given category is provided by the sum of elements of the
fundamental matrix. These values are shown in the last column
(Table 6). Thus, in the long run, farms in S6 (100 to 174 acres)
and S9 (500 to 999 acres) will, on the average, exist only for five
years before going out of business, while those in S4 (20 to 49
acres) have the longest life, on the average.

The Projection of Farm Unit Numbers
Information on the projected number and distribution of
farms is not only important to present farmers, but also to
younger people who may be contemplating, or training for farm-
ing as a career, as well as to public administrators in the formula-
tion of agricultural policy. It was pointed out previously that the
transition matrix, when pre-multiplied by the base year distribu-
tion of farms, produces the projection for the following time
period. Continual post-multiplication of the results by the transi-
tion matrix gives the projections for as many years as desired. The
base year selected for projection is that of 1978, and the projected
numbers and distributions are shown in Table 7.
The overall pattern of decline recorded earlier is confirmed by
the results of this stochastic model. Of the 303 farm units in
operation in 1982, only 249 are projected to be in operation by
1987. About 54 of the current ones will probably cease farm
operations. As shown, the small farms between 3 and 10 acres
will continue to contain the largest absolute number of farms in
any size category. However, because the base data show increases
in the number of farms between 1978 and 1982 of sizes 175 to
259 acres, and of 500 to 999 acres, these are the only categories in
which increases are suggested over the next 20 years. Never-
theless, these increases occur at a decreasing rate over time. By
about the year 2000, almost all of the largest farms would have
become extinct, and those between 175 and 500 acres would
almost all have gone out of existence. Farms below 175 acres in
general will tend to have a much longer life and will persist in the
system beyond those over 175 acres. If current trends continue,
there is likely to be only about 155 farms altogether in the system
by the year 2000, a decline from 754 in 1950, and from an all-
time (recent) high of 828 in 1940.

Explanation of the Decline in Farm Numbers
The agrarian tradition in the territory of which older Virgin
Islanders speak may be traced in recent times to that period
around 1933 when the repeal of prohibition in the United States
increased the demand for sugar, molasses and rum, and in 1934
when the Federal Government created the Virgin Islands Com-
pany to stimulate the economy through the operation of sugar,
rum, and hotel businesses. The initial expansion of agricultural
activities led to the creation of a large number of farms in 1940,
and increases in acreage under the plough reached its zenith in
1950, but the rate of growth was not sustained for long. Not even
another breath of life by the Federal Government in 1949 could
insure a sustained level of development based on agriculture.
Thus was initiated another spiral of decline in this industry which
persists to the present. The foregoing analysis addressed several
quantitative dimensions of the decline, and in this section, an ef-
fort will be made to provide reasonable answers to why? this
decline has been taking place. In so doing, an examination will
be made of the impact of the abandonment of sugar production,
the development of tourism, the increase in industrial and com-
mercial activities, the competition from imported foodstuffs, and
the effect that policies or actions of government have had.
When in 1949 VICORP was succeeded by VICO without the
blessing of Congress in the continuation of rum production, it
was left with the unprofitable sugar plantations, hotel and public
utilities (Miller, 1979). By 1965, it was clear that the industry was
feeling its death throes, since the single sugar mill in St. Croix
had been sold by VICORP to a private concern, and the terms of
sale required operation only until the end of the 1965-66 crop. At
the close of the season, the owner announced that the factory
would cease operations due to the substantial losses that were sus-
tained in the previous year. This implied the elimination of the
sugar industry involving over 4,000 acres of cane land, 113 farms,
and a gross farm return of more than $600,000 in a single year
(Blaut et al., 1965).



An alternative for cane farmers proved problematic for two
reasons. First, they had little experience with other crops after
generations of monocultural sugar production, and many had
neither the capital to convert to new crops nor reliable markets for
such crops. Second, demand for land for residential uses was so
great that much of their land would have been sold for urban uses
if the farmers did not have an alternative replacement of their in-
come loss from the extinct cane industry. Even though it was
recommended that "sugar be replaced by other agricultural enter-
prises," and that ". .. every possible step be taken to retain, and
reconstruct, the agriculture of St. Croix, provided only that the
reconstructed agricultural industry must prove itself profitable"
(Blaut et al., 1965), the abandonment of sugar led to a rapid and
irreversible change from a predominantly rural, agricultural land-
scape to an urbanized or suburbanized one. That the number of
farms decreased from 501 in 1960 to 466 in 1970 (Table 1), and
produced the largest percent change of 54.5% in the study
period, and farm acreage dropped from 35,539 to 20,470 acres, a
change of 48.2%, are clear indicators that the stage may have
been set for an irrevocable decline.
The unprecedented growth of tourism in the 1960s served to
impact on agriculture in at least three ways. It created a huge de-
mand for labor, it induced considerable growth in population,
and it exerted pressure on the land resource. As the number of
tourist facilities increased to accommodate the rising tide of
tourists, economic opportunities multiplied and attracted the
seasonally employed sugar workers and the unemployed. Given
the social stigma that clings tenaciously to farm work throughout
the region, many a farm laborer willingly traded his overalls for a
bellboy's garb. Not only was income from sugar associated with
low-wage employment tourism was considered prosperous. This
led one government official to observe that "income from tourism
over the past five years has more than tripled the combined
returns from rum and raw sugar production" (Economic Policy
Council, 1979).
The construction industry, spurred by the rising need to
accommodate tourists, contributed to the decline of agriculture
in two ways. In the first place, it too created its own demand for
labor, which served to entice labor from farming. Secondly, the
demand was met primarily by immigrant labor. The great influx
of these workers increased the need for housing so acutely that
there was little alternative but to encroach on agricultural land.
This was the case in St. Thomas where public housing complexes
and an 18-hole golf course and condominium complex speeded
the transition from rural to urban uses. In St. Croix, two golf
courses had the same effect. Thus the suburbanization that Blaut
et al. (1965) advised against became a reality. In lamenting the
epitome of this process, one report noted that since the early
1960's, agricultural land on St. Thomas had dwindled to a mere
1,448 acres. It continued: "The encroachment of residential ...
development has brought this about and is worsening the situa-
tion The potentials for any large-scale development on St.
Thomas are very low" (Virgin Islands Planning Office, 1977).
In view of the limited land resource in the Virgin Islands, it is
fair to say that any plan for agriculture would recognize that one is
dealing with an irreplaceable natural resource that is not only scarce
but expensive. And that once agrarian land is committed to an
alternative use, it is extremely improbable that it will ever be
reconverted to productive agrarian use. This is perhaps most likely
to be so for land that is used for commercial or industrial uses.
While the major inroads into agrarian land use came from
tourist facilities and commercial establishments on St. Thomas
and St. John, two major industrial complexes characterized the
diminution in St. Croix. Despite the fact that some 18,689 acres

are in agricultural use there (U.S. Bureau of the Census, 1982),
and it still has potential for expansion of farming activities, grave
concerns are being expressed about future development. Trends

indicate that "St. Croix is showing signs of a pre-industrialization
mood, and that agricultural development may fall off through
the leasing or sale of large tracts to industrial companies ((Virgin
Islands Planning Office, 1977). In St. Thomas, both commercial
and business usage exceed the zoned acreage, and in St. Croix,
the increasing industrial base-with a possible additional oil
refinery -will necessitate a substantial increase in consumption of
the once highly productive agricultural land. Consensus for this
view is summarized in this statement: "It is government policy
which eventually determines where emphasis should be placed.
In the Virgin Islands today business and commercial
developments are top-ranking with industrial [sic] or even above.
Agriculture, on the other hand, is ranked lowest in priority"
(Virgin Islands Planning Office, 1977).
An additional set of factors which help to explain the decline of
agriculture is what McElroy refers to as the "complex of both
internal and external forces" (1979). His delineation includes the
traditional high volume export-import orientation embedded in
the local economy, together with a combination of relative afflu-
ence, urbanization and supermarket tastes. The territorial status
of the Virgin Islands and its geographic proximity provide
relatively easy access to, and penetration by, a volume of
comparatively low-cost suppliers of a variety of foodstuffs, includ-
ing staple items like eggs, chicken, milk, pork, beef and their
derivatives, as well as vegetables (fresh, refrigerated and tinned).
Despite the fact that there is no commercial production of
vegetables in the islands and 99% of the food consumed is im-
ported (Department of Agriculture, 1980), a visiting trade mission
found cause to express concern over the lack of consistent
marketing practices ranging from quality control through regular
delivery and distribution routines (Economic Policy Council, 1979).
Even though an official agricultural policy document does not
exist, there is little question that the impact of government action
on agriculture in the territory has been considerable. It is also evi-
dent, however, that there is no consistency in policy, for while
one branch may proclaim the positive steps by the administration
to promote agrarian development, another may at the same time
deplore its apparent regressive actions.
In reference to the economic policy which contributed to the
alienation of prime agrarian tracts after 1966, to heavy industry
and ". .. which indirectly spawned widespread suburban sprawl
by sponsoring labor-intensive tourism, federal highway construc-
tion and laissez-faire finance and realty practices .. .", McElroy
(1979) called this an "anti-agricultural policy" that was responsi-
ble for the ".. annual declines recorded in the number of farms
in operation and in the amount of acreage under cultivation."
While the Department of Agriculture (1980) stated that "the
basic mission of agriculture is self-sufficiency in food
production," the Economic Policy Council (1979) believed that
"there is no chance of the Virgin Islands ever becoming self-
sufficient in food." This latter is given credence by the Planning
Office's belief that agriculture is lowest among government's
Varying views of agriculture have been expressed as a "vogue-
like preoccupation with self-sufficiency" (McElroy, 1979) and as a
sector ". of our economy which manages to receive loving
remarks, supportive statements and other types of accolades, but
little of the money, and less and less active interest on the part of
the general populace. Everyone wants the output of the farms,
but little of the work involved" (Economic Policy Council, 1979).
The Department of Agriculture (1980) records that efforts to
revitalize agriculture have intensified because of an increasing
dependence on imported food, concerns over energy conservation
and competing land use, the emergence of several back-to-the-
land subcultures, and a realization that agriculture is an integral
component of the territory's economic development. Yet there is
an apparent contradiction in the kind of public evidence which



suggests that 91% of Virgin Islanders surveyed feel that it is "im-
portant" or "very important" for government to exert efforts to
expand agriculture (Mills, 1979), and the conclusion by the
Department of Agriculture that very few young people are cur-
rently involved in, or entering, farm production (1979). It iden-
tified the obstacles in the path of new farmers to be the
unavailability of land, inadequate capital, and lack of
technological assistance. Padda (1979) also singled out the lack of
trained personnel, a shortage of labor, inadequate supplies of
water and insufficient marketing facilities as factors that inhibit
the development of agriculture and which contribute to its
decline. Still, the moribund state of agriculture in the territory
cannot be attributed to a lack of effort on the government's
behalf as the following evidence indicates.
Existing policy includes the following initiatives taken by

1. A sorghum production subsidy in the form of a direct pay-
ment of $40.00 per acre to farmers who cultivate land in
2. A 95% exemption from real property taxes for land of-
ficially certified in use for agriculture;
3. A 90% reduction of tax on income derived from
agriculture to any applicant who is certified;
4. The provision of a number of direct services to small farms
(like land preparation, fertilizer, seeds, and slips);
5. The enforcement of zoning and building regulations to
minimize the relentless pressure from residential and com-
mercial encroachment (Mills, 1983); and

6. The acquisition of land primarily for farming purposes,
such as the purchase of the Harvland property for $6.4
In the final analysis, it is patently obvious that, given the over-
whelming priority accorded to tourism in the local economy,
agriculture in general will never be able to compete as a viable
enterprise in the market place in the foreseeable future. Yet this is
not to be considered an endorsement of a dirge over agriculture.
On the contrary, it is to emphasize that it would be misleading to
treat agriculture solely as a business in the market economy. The
severely limited land resource dictates that even at the cost of heavy
subsidization by both the local government and federal farm pro-
grams, agrarian land should be protected from further encroach-
ment by nonfarm uses. The simple view is that land devoted to
agriculture is a far more desirable use than the several other com-
peting uses with their potential for closing off the "commons,"
introducing visual blight, or despoiling the environment.
The frustration of agricultural officials is clear evidence that the
existing package of tax incentives, subsidized in-kind services,
and input prices are quite inadequate to stave off the continual
infringement on agrarian land. It appears that nothing short of a
full and conscious policy commitment by the highest levels of
government, expressed in deeds and not political rhetoric, re-
garding the role that agriculture is to perform in the future
economy of the Virgin Islands, will arrest the persistent slide that
will make agriculture, by the year 2000, a thing of the past. For it
is worth repeating that once agricultural land is committed to an
alternative use, it is extremely unlikely that it will ever be re-
turned to the productive agricultural domain.

1. Bartholomew, D.J. 1982. Stochastic models for social processes. (3rd ed.).
New York: John Wiley & Sons.
2. Blalock,Jr., H.M. 1979. Social statistics. New York: McGraw-Hill Book Co.
3. Blaut,J.M., F.X. Mark, and A.E. Dammann. 1965. Report to the Governor
of the United States Virgin Islands on the reconstruction of the agriculture economy
of St. Croix. Virgin Islands: College of the Virgin Islands, Caribbean Research In-
4. Collins, L. 1975. An introduction to the Markov chain analysis. Norwich:
University of East Anglia, Geo Abstracts, Ltd.
5. Collins, L., R. Drewett, and R. Fergfuson. 1974. Markov models in
geography. The Statistician 23(3/4):179-209.
6. Dovring, F. 1962. Farm size data: Frequency distribution, interpolation,
and projection. (Res. Rep. No. AERR-50): Illinois: Agricultural Experimental Sta-
tion, University of Illinois College of Agriculture.
7. Economic Policy Council. 1979. Economic policy guidelines: Vol. 2,
Background narrative. Virgin Islands: Department of Commerce.
8. Judge, G.G., and E.R. Swanson. 1961. Markov chains: Basic concepts and
suggested uses in agricultural economics. (Res. Rep. No. AERR-49): Illinois:
Agricultural Experimental Station, University of Illinois College of Agriculture.
9. Kemeny, J.G., A. Schleifer, Jr., J.L. Snell, and G.L. Thompson. 1962.
Finite mathematics with business applications. NewJersey: Prentice-Hall, Inc.
10. Kemeny, J.C., and J.L. Snell. 1976. Finite Markov chains. New York:
11. Krenz, R.D. 1964. Projection of farm numbers for North Dakota with
Markov chains. Journal of Agricultural Economics Research 16(3):77-83.
12. Miller, R.W. 1979. The Virgin Islands Economy. Washington, DC: Office
of Territorial Affairs, Department of the Interior.
13. McElroy, J.L. Agricultural policy in a scarce and fragile environment. In:
D.S. Padda (Ed.), 9th Annual Agriculture and Food Fair of the Virgin Islands,
1979, pp. 17-20. Virgin Islands: V.I. Department of Agriculture and College of the
Virgin Islands Cooperative Extension Service.

14. Mills, F.L. 1979. Public evidence for a vigorous agricultural program. In:
D.S. Padda (Ed.), 9th Annual Agriculture and Food Fair of the Virgin Islands,
1979, pp. 9-11. Virgin Islands: V.I. Department of Agriculture and College of the
Virgin Islands Cooperative Extension Service.
15. Mills, F.L. 1983 (May). Land-use change in a microstate: The case of the
U.S. Virgin Islands. Paper presented at the meeting of the Caribbean Studies
Association, Santo Dominigo, Dominican Republic.
16. Padda, D.S. 1979. Developing a viable agriculture industry in the U.S.
Virgin Islands. In: D.S. Padda (Ed.) 9th Annual Agriculture and Food Fair of the
Virgin Islands, 1979, pp. 24-16. Virgin Islands: Department of Agriculture and Col-
lege of the Virgin Islands Cooperative Extension Service.
17. U.S. Bureau of the Census. 1961. U.S. Census of Agriculture: 1959. 1(54),
Virgin Islands. Washington, DC: U.S. Govt. Printing Office.
18. U.S. Bureau of the Census. 1966. Census of Agriculture: 1966. 1(53),
Virgin Islands. Washington, DC: U.S. Govt. Printing Office.
19. U.S. Bureau of the Census. 1972. 1969 Census of Agriculture: 1(53), Virgin
Islands. Washington, DC: U.S. Govt. Printing Office.
20. U.S. Bureau of the Census. 1977. 1974 Census of Agriculture: 1(54), Virgin
Islands of the United States. Washington, DC: U.S. Govt. Printing Office.
21. U.S. Bureau of the Census. 1980. 1978 Census of Agriculture: 1(54), Virgin
Islands of the United States. Washington, DC: U.S. Govt. Printing Office.
22. U.S. Bureau of the Census. 1983. 1982 Census of Agriculture: 1(54),
Geographic Area Series, Virgin Islands. Washington, DC: U.S. Govt. Printing Of-
23. Virgin Islands Planning Office. 1977. Land use and housing elements: U.S.
Virgin Islands. V.I.: Office of the Governor.



The Caribbean Food Crop Society

How it All Started

Hugh C. Miller
A Founding Member

How pleasant it is to recall the years which followed close on
the end of World War II! Years which witnessed the creation of
many cooperative institutions reflecting man's eagerness to share
experiences and activities with his comrades.
The mood of the times found expression in many publications
but perhaps the most widely circulated of these was Wendell
Wilkie's One World.
During the war, the menace of the German U-boats which
had, at one time, threatened to isolate the Caribbean islands
from supplies from outside the area, had been effectively blunted
by the activities of a Caribbean Commission-representing the
nations which exercised sovereignty over most of the Caribbean
Islands in those days. This Commission had organised movement
of supplies up and down the Caribbean island chain with
minimal exposure to the submarine threat. So impressive was the
success achieved by the Commission in this activity that the
member governments decided, despite the pressures and preoc-
cupations of World War II, to expand Caribbean cooperation in-
to the social, educational and economic fields.
But for the individual islands, the early post-war period
ushered in the era of the "Winds of Change" and the emergence
of movements towards independence and national sovereignty.
Reflecting these developments, the Caribbean Commission
with membership drawn from metropolitan countries exercising
sovereignty in the area, was replaced in 1961 by the "Caribbean
Organisation" with membership drawn from the Federation of
the West Indies, the Commonwealth of Puerto Rico, the Virgin
Islands of the United States, France for its departments in
Guyana, Martinique and Guadeloupe, the Netherlands Antilles,
Surinam and Guyana. The governments of Great Britain, the
United States of America and The Netherlands were represented
in the Council of the Organisation as "observers."
Itself a creature of the trend toward international cooperation,
the Caribbean Organisation established as its main objective the
promotion of cooperation, sharing of knowledge and experience
between member countries, and exploring and exploiting oppor-
tunities for united action on a broad cultural, social and economic
Among the areas to which special attention was addressed were
intra-Caribbean trade and sharing of agricultural experience and
research. In pursuit of these objectives the Caribbean Organisa-
tion with the cooperation of the government of the Com-
monwealth and the University of Puerto Rico organised in
February 1962 a demonstration tour in Puerto Rico on the pro-
duction and marketing of vegetables and food crops.
Some 70 participants representing 21 Caribbean countries, and
including research and extension specialists, farmers and other
persons with an interest in the production, processing and/or
marketing of food crops and farm supplies attended the five-day


With the help of the translating services provided by the Carib-
bean Organisation, papers were circulated and discussion
facilitated between persons who previously had been separated by
differences of language as well as by metropolitan affiliation.
It is not surprising that, by the time the tour had ended, con-
siderable interest had been generated in the idea of creating
facilities for securing, on a permanent and continuing basis,
cooperation and sharing of experience and knowledge between
scientists and farmers and, indeed, all persons within the Carib-
bean area interested in any aspect of food production and
Among the tour participants, Dr. Richard Bond, Officer in
Charge of the U.S. Federal Experiment Station at Kingshill, St.
Croix, in the U.S. Virgin Islands and Dr. Arnold Krochmal, Hor-
ticulturist attached to the Station, decided to take positive action
to secure the establishment of the facilities needed.
With characteristic enthusiasm and persistence, Arnold
Krochmal, aided and abetted by his chief, set about the task of
securing support and active assistance from the Caribbean
Orgnisation and certain key personnel within the Caribbean
region who enjoyed wide respect and repute.

The Caribbean Organisation readily placed secretarial,
translating and interpreting services fully at the disposal of the
small team (A. Krochmal, F. Aponte Aponte and Hugh Miller),
which had begun working to establish a society or association to
achieve the objectives sought. As a result, contact was made with
important agricultural leaders in the Caribbean countries served
at that time (1963) by the Organisation. The planners were great-
ly encouraged by the many warm expressions of agreement and
enthusiastic promises of support which they received.

Accordingly, the date for an inaugural meeting for establish-
ment of the society was set as May 3, 1963 to be held at the offices
of the Secretariat of the Caribbean Organisation in Hato Rey,
Puerto Rico. Invitations for attendance were issued to all those
persons who had expressed interest.
A number of persons responded advising inability to travel to
Puerto Rico to attend but asking that their interest in the forma-
tion of the Society and willingness to seek membership be noted.

The Inaugural Meeting
The inaugural meeting was duly convened. In attendance were
persons resident in St. Croix, U.S. Virgin Islands, ten persons
resident in Puerto Rico, one person representing Barbados, and
four persons representing the Secretariat of the Caribbean


The meeting agreed that the main objective to which the Socie-
ty should be dedicated "is the improvement of Caribbean nutri-
tion and living standards" and stated that "to this end the Society
would seek to:
1. Stimulate and assist in research and the dissemination of
information on food crop production processing and
marketing in the Caribbean area.
2. Provide a consultant service aimed particularly at assisting
the smaller territories in the area.
3. Encourage cooperation between agricultural experiment
stations and between research and extension workers in the
area of Caribbean agriculture.
4. Work in close cooperation with the Caribbean Organisa-
tion and other regional organizations dedicated to the pro-
motion of cooperation between the countries of the Carib-
bean area."
At the inaugural meeting a decision was taken that annual
meetings of the Society would be rotated between the various
countries represented in its membership.

The meeting also agreed that membership should be open to
all persons in sympathy with the aims of the Society and that
there should be (i) Active members paying dues of US$5.00 per
annum; (ii) Sustaining members paying a minimum of
It was decided that Honorary Membership could be awarded to
persons who, in the opinion of the Board of Directors, had made
outstanding contributions to the achievement of the objectives
sought by the Society.
It was also agreed that all persons attending the inaugural
meeting and Dr. G.P. Tiggelman of Surinam should be tested as
founding members. The list of founding members is as follows:

Founding Members of the Caribbean Food Crop Society

Dr. R. M. Bond

Dr. Arnold Krochmal

Mr. A. de K. Frampton

Mr. Francisco Aponte Aponte

Mr. Miguel Gonzilez Flores

Dr. J. Velez Fortufio

Dr. H. Azzam

Dr. Jorge Mejia Mattei

Mr. Carlos D. Colerado

Mr. C.P. Erskine Lindo

Officer in Charge
Federal Experiment Station,
St. Croix, U.S. Virgin Islands
Horticulturist Federal
Experiment Station,
Kingshill, St. Croix, U.S.V.I.
Chief Agricultural Officer,
Horticulturist Agriculture
Extension Ser., University of
Puerto Rico
Horticulturist Agriculture
Ext. Services, University of
Puerto Rico
Head Plant Breeding Dept.
Agr. Exp. Station, University
of Puerto Rico
Plant Breeder, Agriculture
Experiment Sta., University
of Puerto Rico
Director, Division of
Marketing Regulation,
Ministry of Agriculture and
Commerce, Puerto Rico
Representative of Agriculture
Chemicals, The Shell Co.
(P.R.), Ltd.
Chief Admin. Officer,
Central Secretariat
Caribbean Organisation

Mr. G.C.L. Gordon Development Officer (Social
Affairs), Central Secretariat,
Caribbean Organisation
Mr. A.J. Seymour Development Officer (Culture
and Information)
Central Secretariat
Caribbean Organisation
Mr. G.P. Tiggelman Director of Agriculture
Mr. H.C. Miller Development Officer (Natural
Resources) Central Secretariat
Caribbean Organisation
The Meeting elected the persons listed below to serve as the
first Board of Directors of the Society.
President Dr. Richard M. Bond
The United States Virgin Isls.
Vice President F. Aponte Aponte
The University of Puerto Rico
Other Directors Hugh C. Miller of the
Caribbean Organisation
Dr. Arnold Krochmal of the
United States Virgin Islands
Dr. H. Azzam of the
Agriculture Experiment Sta.,
University of Puerto Rico
A. de K. Frampton of
R. Osbourne of Jamaica
The inaugural meeting was then adjourned. A short meeting
of the Board of Directors was convened and at this meeting Mr.
H.C. Miller was elected Secretary and Dr. A. Krochmal,
Treasurer, to serve until the first annual General Meeting.
Second Meeting of the Board of Directors
The second meeting of the Board of Directors of the Society
was held at the Central Secretariat of the Caribbean Organisation
on May 14, 1963.
At this meeting draft articles of Association and regulations
were approved for legal documentation.
The president proposed and the meeting agreed that in view
of the short period of time normally needed to secure registration
in St. Croix, the Society should be registered in that island.
It seems that this decision was later found impractical of im-
plementation, and that registration of the Society as a legal entity
was delayed until the early 1980s, during the tenure of Dr. Ale-
jandro Ayala as president.
It was decided that the first Annual General Meeting of the
Society would be held in St. Croix, U.S. Virgin Islands, on Oc-
tober 7th to 11th, 1963.
Between Inauguration and the first Annual General Meeting,
Dr. Krochmal devoted considerable effort and skill to promoting
the development of an active service of expert technology transfer
directed mainly at the smaller territories of the West Indies
Federation. He eagerly sought out problems, discovered ap-
propriate experts who would assist and raised funds and exploited
all possible means to secure that the necessary assistance was
given. For his pioneering efforts and his skill in securing financial
assistance, in the difficult early years of the Society's life, we owe
him a great debt. Indeed, he played a dominant role not only in
the conception of the Society but in its pre-natal, infant and early
childhood stages.
On the occasion of the Society's Coming of Age, it is fitting
that we all pay special homage to Arnold Krochmal- to his vi-
sion, his dedication and to the zealous and assiduous activity on
behalf of the Caribbean Food Crop Society, which he displayed
all the time he served in this region of the world.



At our First Annual General Meeting held in St. Croix in Oc-
tober 1963, Arnold Krochmal was elected secretary/treasurer and
in that position he continued to provide dedicated and energetic
service to the Society until his transfer from the area in 1964 when
these duties of secretary/treasurer were transferred to Dr. George
Samuels and later shared between Dr. George Jackson serving as
secretary and George Samuels serving as treasurer.

The invaluable services rendered to the Society by these
distinguished scientists and by our present treasurer Dr. Miguel
A. Lugo-Lopez and secretary Carlos Cruz, are well known and ap-
preciated by the great majority of our membership. To all these
gentlemen, as well as to our past presidents and members of our
board of directors, we all, I am sure, would wish to pay fitting
tribute on this the twenty-first anniversary of the establishment
of the Caribbean Food Crop Society.




Defoliators and Sap Sucking Insects of Pigeon-Pea

in Barbados, West Indies

M. M. Alam I. H. Gibbs
CARDI/Sugar Technology Research Unit
Edgehill, St. Thomas, Barbados, W.I.

Like most other crops, pigeon-peas are attacked by several
insects, some of which cause heavy crop losses. These pests re-
quire special attention to arrest their damage, while others
cause limited damage and need few or no control measures.

During these studies, from twenty-two pest species recorded
in Barbados, eight were feeding on leaves, and fourteen suck-
ing sap from leaves, stems and pods. A number of indigenous
natural enemies attacking these pest were also recorded.

1. Velvet Bean Caterpillar, Anticarsia gemmatalis (Hubner)
In Barbados, occasional outbreaks cause serious defoliation on
peigeon-pea and beans.
The adults are 1.3-1.8mm long, with a wing span ranging from
3.3-4.0cm. Forewings are pale greyish-brown; a narrow pale line,
with a dark margin on either side of it, traverses both wings
diagonally. The larvae are relatively slender, either green marked
with longitudinal lines, or more brownish, with more prominent
longitudinal lines. Eggs are ribbed, circular and dome-shaped.
The eggs are laid in clusters on the leaves. The larvae which
move with a looping action, feed on the leaves, and after
cdefoliating one plant, they move on to another. When disturbed,
they drop to the ground with pulsating movements. Pupation oc-
curs in the soil or among the debris on the ground.
The pest is widely distributed in the Caribbean, the United
States of America and Latin America.
It also feeds on beans (Phaseolus spp., Phaseolus vulgarir),
woolly pyrol (Phaseolus mungo), bonavist bean (Lablab niger
[ = Dolichos lablab]), peanut (Arachis hypogaea), sugarcane (Sac-
charum officinarum), wild dolly (Macroptilium lathyroides),
shame bush (Mimosa spp.) and several other cultivated and wild
Indigenous natural enemies include Carinodes havanensis
(Cameron) (Ichneumonidae) and Brachymeria ovata (Say)
(Chalcididae)- Parasites. Cycloneda sanguinea (L.) (Coc-
cinellidae); Chrysopa sp., Chrysopa lanata (Banks) and Chrysopa
limitata (Navas) (Chrysopidae); and Polistes barbadensis
(Richards) (Vespidae)- Predators.
The eggs of A. gemmatalis are parasitised by an introduced
species, Telenomus remus (Nixon) (Scelionidae) and the larvae by
Bracon sp. prob. hebetor (Say) (close to Bracon brevicornis
[Wesmeal]) (Braconidae).

2. A Leaf-tip roller, Caloptilia sp. (Lepidoptera:Gracillari-
This is a minor pest. A single egg is laid in a slightly curled
leaf-tip. On hatching, the larva rolls up the leaf tip further and
secures it with a silken thread, thus forming a hollow tube in
which to feed. As the larva grows in size, the leaf roll is also
Initially the larva lacerates the leaf cells and sucks the exuding
sap. At a later stage it feeds on parenchyma. Owing to the small
size of the larva, the actual damage to the leaf is negligible, but
the infested leaves, due to lack of photosynthesis, eventually die
and fall prematurely. Pupation occurs in the leaf roll.
In Barbados, it is parasitised by Asympiesella sp. (Eulophidae).


3. The Sugarcane Root-borer, Diaprepes abbreviatus (L.)
Generally this is a minor pest, but during outbreaks, pigeon-
pea is a favorite host plant on which the adults congregate, mate,
feed and lay eggs. During such times the plants are heavily
Alam (1976) reported on the general behavior, life-cycle, alter-
nate host plants, and discussed various methods of control.
Besides the indigenous and exotic natural enemies reported by
Alam (1976), three additional parasite species, viz. Tetrastichus
sp. prob. haitiensis (Gahan) and Horismenus sp. prob. cupreus
(Ashm.) (Eulophidae) and Ufens sp. (Trichogrammatidae), at-
tacking the eggs of Diaprepesfamelicus (Gyll.) on Citrus spp., in
Montserrat, were introduced into Barbados. As D. abbreviatus
tends to lay eggs on citrus leaves, these parasites were released in
citrus orchards, but no recoveries were made.
As the adults are attracted in large numbers to pigeon-pea,
maize and citrus, these plants may be sprayed with a fast acting,
non-residual insecticidess, such as Malathion, Dibrom (naled),
Dimecron, Elecron, Ekalux or Pyrethrins (Fewkes, 1979).
Soil treatment with persistent organochlorine insecticides such
as Chlordane, applied at the rate of 1 kg. a.i. /ha against first and
second instar larvae, 3 kg a.i./ha against third instar larvae and
Heptachlor, 7 1/ha of 3E concentration (also available as the
granular formulation) have been tried and recommended (Alam,
1976). Chemicals should be incorporated into the soil during
preparation of the land immediately before or at planting.

4. Promecops lunatus (Fhs.) (Coleoptera:Curculionidae).
The adults fray the leaf edges of the crop. A heavy attack causes
serious damage. The biology and natural enemies have not been
Chemical control as for Diaprepes is applicable for this species.

Sucking Insects
1. The Green Stink-bug, Nezara viridula (L.) (Hemiptera:
In Barbados this is a minor to negligible pest. The adults and
nymphs suck sap from tender leaf-stalks and pods.
Adults are green, shield shaped and rather flattened dorsally.
The egg is about 1mm high and cylindrical, about 1.3 times as
high as wide. It is creamy-yellow at first, changing to orange
before hatching. The eggs are laid on the leaf surface in rows
forming a hexagonal cluster of about 30 to 100 eggs. The incuba-
tion period is about 5 days. The newly hatched nymphs remain
clustered for a day near the egg-shells, then gradually disperse
and start sucking the cell sap from the leaves. They pass through
five moults before reaching the adults stage. The nymphal stage


lasts for 20-43 days. Mating starts one to two days later, and egg-
laying beginning in a further two to three days.
The pest is pan tropical and is present in all islands of the
Lesser Antilles and all the warmer parts of the Americas. It has
also been recorded in cotton (Gossypium barbadense), sweet
potato (Ipomoea batatas), beans (Phaseolus spp.), tomato
(Lycopersicon esculentum), pepper (Capsicum annuum), okra
(Hibiscus esculentus), squash (Cucurbita spp.), eggplant
(Solanum melongena), spider plants (Cleome spinosa and
Cleome viscosa), stinking miss (Gynandropsis gynandra) and
several other cultivated and wild plants.
In Barbados and the East Caribbean islands, the eggs are
parasitised by Trissolcus (= Asolcus) sp., Trissolcus (= Asolcus)
basalis (Wollaston) and Telenomus sp. (Scelionidae).

2. The Green and Brown Stink-bug, Edessa meditabunda
(F.) (Hemiptera:Pentatomidae).
Generally this is a minor pest. The nymphs and adults suck sap
from the stems and pods.
Adults are bright green, somewhat polished. Eggs are about
1mm high, pale green, approximately spherical.
The eggs are laid on the leaves, usually in a cluter of about
fourteen, arranged in two rows of seven eggs each. These hatch in
about five days. Newly hatched nymphs are orange-yellow, with
dark markings, These remain congregated near the empty egg-
shells for some time and then disperse and start feeding. There
are five nymphal instars. The life-cylce occupies about a month.
The pest has been reported from Trinidad, the Leeward and
Windward islands, Haiti and Suriname. It also attacks beans
(Phaseolus spp.), cotton (G. barbadense), eggplant (S.
melongena), Black nightshade (Solanum nigrum), wild tomato
(Solanum torvum), okra (H. esculentus), tomato (L.
esculentum), citrus (Citrus spp.), English Clammy cherry (Cordia
alba and Cordia obliqua), white broomweed (Parthenium
hysterophorus) and several other cultivated and wild plants.
The eggs are parasitised by Trissolcus sp. and Telenomus sp.

3. The Leaf-hoppers, Empoascafabae (Harris) and Empoasca
fabalis (DeLong) (Hemiptera:Cicadellidae).
These are important pests. The nymphs and adults suck sap
from the leaves and pods. Because of their abundance and role as
disease carriers, these pests need special attention.
The adult is about 3mm long, slender and wholly green. The
egg are laid into the stems or in the leaf midribs. Incubation
period is about ten days. The young nymphs are bright green,
feed on the underside of the leaves, and run rapidly if disturbed.
Before reaching the adult stage, the insect passes through five in-
stars in 12 to 15 days. Four days after mating, the female starts
laying eggs. An individual female lays two to three eggs at a time,
and may live for three to four weeks. The insect is capable of
transmitting a virus disease of beans (bean yellows).
These species are widely distributed in the Lesser Antilles and
have also been recorded from beans (Phaseolus spp., P. vulgaris),
woolly pyrol (P. mungo), bonavist bean (L. niger = D. lablab),
and a number of cultivated and wild plants.
Fennah (1947) reported Anagrus empoascae (Doz.)
(Mymaridae) as an egg-parasite, in the West Indies. C. sanguinea
and Nephus sp. (Coccinellidae) and Chrysopa sp., C. lanata and
C. limitata, feed on nymphs and adults.

4. A Cottony-cushion Scale, Icerya sp. prob. purchase
This is generally a minor pest but occasionally large popula-
tions occur on ratoon plants. The nymphs and adults suck sap
from the stems. During heavy infestations, leaves and stems are
covered with characteristic white, fluted, cylindrical insects. In-

tested leaves turn yellow and many of them drop prematurely.

Young, heavily infested shoots die quickly. The scale produces
enormous amounts of honeydew, which under dry climatic condi-
tions, look like white globose cyrstals.
The mature female is 4-8mm in length, and is covered with
white wax. The anterior and posterior filaments are long and
thick, the remainder very short, not pointed. A large, white,
fluted egg sac produced by the female can be two and a half times
larger than the scale insect. The large egg sac produces 600-800
reddish eggs, over two to three months.
The eggs hatch in a few days. The newly hatched nymphs are
reddish-brown in color and pass through three instars before
reaching the adult stage. The young crawlers settle on leaves and
twigs with some initial yellowish wax formation, and soon acquire
a reddish-brown color. The full-grown insects settle, often in
large numbers, on the branches, twigs and young shoots. Sexual
differentiation takes place during the second instar. Males are
The pest is distributed in the Caribbean, and has been
reported from Puerto Rico, the Lesser Antilles and Trinidad.
It has also been recorded on citrus (Citrus spp.), guava
(Psidium guajava), Spanish oak (Inga laurina), saman (Samanaea
saman), shrubs (Acacia spp., and Acaciafarnesiana), Locust berry
tree (Byrsonima coriacea var. spicata), Barbados evergreen (Ficus
retusa var. nitida), an erect herb (Acalypha poiretii), and several
other cultivated wild plants.
The predators recorded in Barbados are Chilocorus cacti (L.),
Diomus sp. and Rodolia cardinalis (Muls.) (Coccinellidae), which
prey upon nymphs and adult females.
5. Black scale, Saissetia oleae (Bernard) (Hemiptera:
This pest is believed to be of African origin and has spread
throughout the world. The females and nymphs suck sap from
the stems of pigeon-pea. The female is about 4mm long and
2.5mm high, dark-brown or black in color.
A female lays about 1,000-4,000 eggs under its body. Freshly
laid eggs are white in color, changing to orange or brown in color
later. The young nymphs are flat, elongate-oval and pinkish-
brown in color. The crawlers begin feeding a few hours after
emergence. Whereas the adults usually occur on shoots and
twigs, the crawlers prefer to settle on the underside of the leaves
and on shoot tips. The males, which are rare, pass through a
pupal stage. Ordinarily, reproduction occurs without fertiliza-
It has been reported from the Greater and Lesser Antilles and
The pest has also been recorded on cotton (G. barbadense and
Gossypium hirsutum), guava (P. guajava), citrus (Citrus spp.),
hog plum (Spondias mombin), oleander (Nerium oleander),
avocado (Persea americana), small red trubba (Solanum
ficifolium), Barbados or Indian almond (Terminalia catappa),
henna (Lawsonia inermis), black-eyed susan (Thunbergia alata
and Thunbergiafragrans).
In Barbados, it was parasitised by Lecaniobius cockerellii
Ahmead (Eulophidae).

6. A number of minor leaf sucking pests recorded were:
Saissetia coffee (Walker), Saissetia hemispherica (Targioni-
Tozzetti), Asterolecanium cajanus and Asterolecanium pustulans
(Cockerell) (Asterolecaniidae), Howardia biclavis (Comstock)
(Diaspididae), Megalotomus rufipes (Westwood) (Coreidae),
Aphis sp. (saphididae), Liriomyza sp. (Agromyzidae), and
Tetranychus sp. (Tetranychidae).

Amongst the defoliators, the velvet bean caterpillar, Anticarsia
gemmatalis (Hub.), the sugarcane root-borer, Diaprepes ab-
breviatus (L.) and Promecops lunatus (Fhs.), occasionally appear

in large numbers causing serious damage to the crop.


The eggs of A. gemmatalis are parasitised by Telenomus remus
(Nixon) and the larvae by Bracon sp. prob. hebetor(Say) (close to
Bracon brevicornis [Wesmeal]).
During outbreaks, the adults of the sugarcane root-borer, D.
abbreviatus are attracted in large numbers to pigeon-peas, maize
and citrus; these plants may be sprayed with fast acting, non-
residual pesticides, like Malathion, Dibrom (naled), Dimecron,
Elecron, Ekalux or Pyrethrins.
For the control of grubs in the soil, more persistent organo-
chlorines such as Chlordane and Heptachlor should be incorpor-
ated into the soil during land preparation before or at planting.
Amongst the sucking insect pests, the Green Stink bug,
Nezara viridula (L.) and the Green and Brown Stink bug, Edessa
meditabunda (F.) cause some damage to the crop; while the leaf-
hoppers, Empoasca fabae (Harris) and Empoasca fabalis
(DeLong), are the vectors of "Bean Yellows" virus and need
special attention.

The cottony-cushion scale, Icerya sp. prob. purchase (Maskell),
black scale, Saissetia oleae (Bernard) and other pests, appear
mostly on ratoon crops. Pest populations should not be allowed
to develop to serious levels, and infested plants should be sprayed
or destroyed.

1. Alam, M.M. 1976. Recent outbreak of sugarcane root-borer and white grubs
in Barbados. Proc. Meeting West Indies Sug. Tech., 1976, Jamaica, pp. 97-111.
2. Fennah, R.G. 1947. The Insect Pests of Food-crops, in the Lesser Antilles.
Dept. Agric. for the Windward Islands, St. George's, Grenada and Dept. Agric. for
the Leeward Islands, St. John's, Antigua.
3. Fewkes, D.W. 1979. Report on a visit to Barbados 14th to 16th February,
1979. Tate and Lyle Ltd., Reading.



Pigeon-Pea Pod Borers and Their Natural Enemies

in Barbados, West Indies

M. M. Alam I. H. Gibbs
CARDI/Sugar Technology Research Unit
Edgehill, St. Thomas, Barbados, W.I.

In Barbados, three pests, Heliothis virescens (F.), Fundella
cistipennis (Dyar) and Callosbruchus chinensis (L.) inflict
serious damage to pigeon-pea pods. Over the years it was
estimated that some 60% pods were destroyed annually.
Although a number of indigenous natural enemies were
recorded attacking eggs, larvae and pupae of these pests, their
populations were usually too low for adequate control.
Between 1968 and 1983, a number of parasite species were
introduced from India, Pakistan, Uruguay, U.S.A. and the

Eastern Caribbean islands; 17 for the control of H. virescens,
seven for F. cistipennis and two for C. chinensis. Of these, two
species, Bracon hebetor (Say), from India and Bracon sp.
prob. hebetor (Say) (close to Bracon brevicornis [Wesmeal]),
from St. Vincent, became established against Heliothis and
Fundella. The levels of parasitism by the latter species ranged
from 2.1 70%, avg. 16.4%, between April and December

The pigeon-pea (Cajanus cajan) is a cultivated annual or peren-
nial shrub grown in many tropical and sub-tropical countries for
its green or dry seeds. In the Caribbean in general and in Bar-
bados in particular, it is planted on the borders of sugarcane
fields. In recent years, because of the greater demand for this
commodity, pure stands are also grown.
In Barbados, the most important pests are the pod-borers, a
noctuid, Heliothis virescens (F.), a pyralid, Fundella cistipennis
(Dyar) and a bruchid, Callosobruchus chinensis (L.).
Between 1968 and 1976, several parasites and predators were
introduced by the Ministry of Agriculture, Food and Consumer
Affairs, from India, Pakistan, Uruguay and the United States of
America, through the Commonwealth Institute of Biological
Control (CIBC), West Indian Station, Trinidad (see Appendix 1
-3). Some of these became established, but their populations re-
mained low.
Since 1977, a search was carried out by the Caribbean
Agricultural Research and Development Institute (CARDI) for
natural enemies of pigeon-pea pod borers, H. virescens and F.
cistipennis; the bruchid, C. chinensis and certain other important
pests throughout the region.
From a number of egg, larval and pupal parasites recorded in
the Eastern Caribbean islands, a Bracon sp. (solitary) attacking F.
cistipennis, and a Bracon sp. prob. hebetor (Say) (close to Bracon
brevicornis [Wesmeal]) a gregarious ecto-larval parasite attacking
H. virescens and F. cistipennis in St. Vincent; a Bracon sp.
(gregarious ecto-larval parasite) on F. cistipennis and An-
cylostomia stercorea (Zell.) in Antigua, St. Kitts, Nevis, Montser-
rat and St. Lucia; and Apanteles etiellae (Viereck) (solitary) at-
tacking F. cistipennis and A. stercorea in St. Kitts, Nevis and
Montserrat, were of greater importance for the control of these
pests, in the countries where these were absent. Of these, Bracon
sp. prob. hebetor and Bracon sp. (gregarious) were mass bred in
the laboratory on Trachylepidia fructicassiella (Rag.) larvae.
These two species were released in pigeon-pea plots throughout
the island, and recoveries were made in the field. It appears that
at present the former species is the most effective, attacking up to
44% Heliothis and up to 70% Fundella larvae in the field.
Observations on the permanent establishment of these two
parasites and their effect on the pod-borer populations are conti-
nuing. Bracon sp. prob. hebetor has also been introduced into
Antigua, St. Kitts, Dominica and St. Lucia.


Trichospilus diatraeae (Cherian and Margabandhu), a pupal
parasite of various pests in India, was introduced into Barbados
against Fundella and Heliothis spp. The parasite seems to prefer
pests pupating on the leaves of their host plants, and attacked
Pseudoplusia includes (Walker) on tomato, Diaphania
(= Margaronia) hyalinata (L.) on cucurbits and Palpita hyalinata
(L.) on French Willow. Heliothis spp., which pupate in the soil,
and Fundella in pigeon-pea pods, thus escaped parasitism.

Pod-Borers and Their Natural Enemies
Heliothis virescens (F.) (Lepidoptera : Noctuidae) is a serious
pest of pigeon-pea in Barbados and other Eastern Caribbean
The larvae bore into the pods and destroy the developing
seeds. In addition to H. virescens, Fundella cistipennis (Dyar)
also attacks the pods. The average pod damage recorded between
1969 76 ranged from 27.8 90.5%, average 61%.
H. virescens is always more abundant than F. cistipennir,
although the latter becomes more prevalent during January to
The egg of H. virescens is creamy-white, dome shaped, with a
small conical micropile at its apex. The sides are grooved with
long and short ridges. They are laid singly on buds, flowers and
young pods. Initially the newly hatched larva feeds on the leaf
surface, flowers, buds and pods, and later bores into the pod. A
single larva can damage most of the seeds in a pod. The full-
grown larva leaves the pod and pupates in the soil.
The life-cycle was studied in the laboratory at 26.3C + 0.2C
and 88% relative humidity. The incubation period lasts three
days. Generally there are five or six larval instars and in a few in-
stances, seven. During these studies, 57.1% larvae moulted six
times; 38.1%, seven times and 4.8% eight times. The time taken
by various instars is given in Table 1.
The pest has been recorded on a wide range of cultivated and
wild plants, including cotton (Gossypium barbadense), tomato
(Lycopersicon esculentum) and sweet potato (Ipomoea batatas).
During these studies, the natural enemies were recorded in
Barbados as listed in Table 2.
Because of inadequate control by indigenous natural enemies,
some seventeen species of parasites and one predator were ob-
tained from India, Pakistan, Uruguay, Arizona (U.S.A.), St.
Vincent and Antigua, W.I. (see Appendix 1).


TABLE 1. Life-cycle of Heliothis virescens, studied in Barbados, W.I.

RangE Av. ri. Range Average
Incubation 3 3 5th instar 2 12 6
Ist instar 3 6 3.7 6th 5 10 8.2
2nd .5 7th 12
3rd 1 7 3.1 Pr-pupal
period 1 4 3
4th 1 i 3.3 Pupal
period 13 19 15.6
Total larval Larval and
period 17 30 21.8 pupal period 32 49 39.9
Complete life-cycle
(i.e. egg laying
to adult emergence) 35 52 42.9

TABLE 2. Natural enemies of Heliothis virescens, in Barbados, W.I.


TABLE 3. Time (hrs.) for the development of the parasite, Bracon sp. prob. hebetor
(Say) (= Bracon brevicornis [Wesmeal]) on H. virescens larvae under laboratory con-


Incubation period 43 0.4 35.24 47.12
Larval period
(three larval instars) 48 0.9 42.00 54.00
Pre-pupal period 47 0.6 41.00 50.00
Pupal period 128 3.0 116.00 150.00
Total development period 266 5.0 267.00 1 5

Most of the parasites obtained from overseas were released
directly in the field, while a few species viz. Apanteles
marginiventris (Cresson), Bracon hebetor (Say), Bracon sp. prob.
bebetor (Say) (= Bracon brevicornis [Wesmeal]), Campoletis
chloridae (Uchida), Campoletis flavicincta (Ashmead) and
Eucelatoria bryani (Sabrosky) were bred in the laboratory, and
some of these were released over a long period of time.
1. Apanteles marginiventris (Cresson) was obtained from the
Indian and Pakistan Stations of CIBC during 1970 and
It is a solitary larval parasite, attacking first and second
instar larvae of Heliothis and Spodoptera species. The
female inserts a single egg into the larval body, and the
parasite develops internally. The full-grown grub emerges
from the larval body and spins a white silken cocoon for
Between 1970 and 1980, it was recovered from the larvae
of Spodoptera eridania (Cramer) on Beta vulgaris and
Solanum melongena.
2. Bracon hebetor (Say), a gregarious, ecto-larval parasite was
introduced from the Indian Station of CIBC during 1970
and 1975, for trials against Heliothis spp. and F. cistipennis.


A small culture was built, and some 3,000 adults were
released in pigeon-pea plots. The parasite was first
recovered in 1973, when 3.0 17.5%, average 7.5% larvae
of H. virescens were parasitised. The average percentage
parasitism was 2.4 in 1974, 6.3 in 1975 and 9.2 in 1976.
3. Bracon sp. prob. hebetor (Say) (very close to Bracon
brevicornis [Wesmeal]). In St. Vincent during February
1983, the parasite attacked medium to full-grown larvae of
H. virescens and Ancylostomia stercorea (Zell.), in pigeon-
pea pods. Some of the field collected material was brought
to Barbados, a culture established and its biology studied.
The parasite mates soon after emergence. The male with
its wings extended laterally, pursues and mounts the
female, quickly bends the abdominal tip and inserts its
aedeagus. During this effort it occasionally vibrates its
wings, while the female remains quiet. The male may re-
quire a number of attempts before it mates successfully.
Mating lasts from one to two minutes. Both male and
female mate several times.
Soon after mating, the female actively searches for host
larvae. On encountering a caterpillar, the parasite sudden-
ly ceases movement and thrusts her abdomen with the
oviposter extended forward between her legs. Maintaining
this position, she gradually moves nearer to the caterpillar,
and with a gentle sting paralyses it instantly. Thereafter,
she may feed on the body wound at intermittent intervals
for several hours, before laying eggs on it. The eggs are laid
loosely on any part of the body.
The biology of the parasite was studied in the
laboratory. The details are given in Table 3.

Between 21 March and 12 April, 1983, 4,500 adult para-
sites were liberated at Fairy Valley, Christ Church. From
April to December 1983, a further 25,870 adults were re-
leased in other parts of the island, and work is continuing.
The parasite was first recovered from Fairy Valley on 19
April, 1983, when 35.2% of the larvae of H. virescens were
parasitised. The overall parasitism ranged from 3.9% to
The initial recoveries show that the parasite may build
up higher populations during wet weather when the pest
population will also increase, and the green pods, a prefer-
red site for attacking the host will also be in greater
4. Campoletis favicincta (Ashmead), a native of Uruguay,
was obtained through the Commonwealth Institute of
Biological Control, West Indian Station, Trinidad, during
August 1981, for trials against Heliothis and Spodoptera
species. The parasite was cultured on Spodoptera larvae,
because of their convenient mass production in the
The parasites mate soon after emergence. The male ac-
tively pursues the female, moving its antennae and wings
vigorously and grasping her with its forelegs, bends the ab-
domen anteriorly and inserts the aedeagus. Mating lasts for
1.50 to 3.35 minutes. Both sexes mate several times.
Mated females show reluctance to mate again, but male(s)
pursue them to remate. Sometimes, over-mating kills the
Usually the female requires a two to three days
preoviposition period after mating, but if the hosts are
available earlier, she will parasitise them. Progeny from
these will be exclusively male.
The parasite prefers two to four day old larvae, but
under forced conditions, it also attacks five to six day old



Ir- clcgramna r. f-ciatum YerK.
2Ia2on sp.
Paras erola (=Perisierola)
sp. prob. nigfriferur (Ashmead)
ArchTtc s tnarnrrtrjs (Townsend)
Arh'-ra'-; nrilii-ntris Wulp
Cclo,;eao a sa:i-irnea (L.)
Npohus sp.
SChryopa sp.
Ch_)yopa laratua Bks.
Chrysraa I imitata Nav.
Polistes barbadensis Richards

Larval parasite

Larval-pupal para.
Preys upon eggs
and young larvae
do -
do -
do -
do -
Preys upon larvae


During 1981, seven generations were produced in the
laboratory. In all, 8,181 Spodoptera larvae (i.e. S.
eridania, S. frugiperda, S. latisfascia and S. sunia) were ex-
posed to the parasite females. Of these, 2,830 (34.6%)
were successfully parasitised. From 2,830 parasite cocoons,
1,656 (58.5%) produced adults, of which 1,332 (80.4%)
were males and 324 (19.6%) were females. All species of
Spodoptera were successfully parasitised.
The female actively approaches the caterpillar, vibrating
its wings and antennae vigorously, and with a quick jab in-
serts a single egg into the larval body. If the host larva in-
itially escapes attack, the female pursues it until it is suc-
Parasitised larvae continue to feed for a few days, before
gradually losing their appetite; growth is arrested and the
larvae become sluggish.
The parasite's life-cycle was studied on S. latifascia, S.
eridania and S. frugiperda. The development period on
these hosts is given in Table 4.

TABLE 4. Life-cyce of Campoletis favicincta (Ashmeand), in three Spodoptera spp.

Development stages Host
of C. flavicincta S. latifascia S. eridania S. frugiperda
Egg-larval period (days) 11.6 + 0.31 10.6 + 0.12 .9.3 + 0.32
Pupal period (days) 6.1 + 0.25 6.0 + 0.07 6.0 + 0.19
Total development
period (days) 17.7 + 0.24 16.6 + 0.13 15.3 + 0.27

These studies show that on S. frugiperda development
took place in the shortest period, but because of its can-
nibalistic habit, was not a suitable host for mass rearing in
the laboratory. Instead, S. eridania, which can be bred very
easily in the laboratory, was used.
Between November 1981 and May 1982, 1,137 adults
(260 females and 877 males) were released in pigeon-pea,
maize, sorghum and alfalfa fields. No recoveries were
made from pigeon-pea fields.
5. Campoletis chloridae (Uchida), a native of India and
Pakistan, was obtained during 1968, 1971, 1975 and 1982,
through CIBC, Trinidad. Its general behaviour is similar to
that of C.Flavicincta. When reared on the larvae of S.
eridania, the egg-larval period occupied 9 to 11 days
(average 10.6 days) and the pupal period lasted for 5 to 7
days (average 6 days). The total development took 14 to 18
days (average 16.6 days).
Between October 1982 and March 1983, 976 laboratory
bred adults (207\females and 769 males) were liberated in
pigeon-pea and other crop fields. In April 1983, two emp-
ty cocoons were recovered from a pigeon-pea pod.
6. Eucelatoria bryani (Sabrosky)-This parsite was obtained
from Arizona (U.S.A.), through CIBC, Trinidad, in 1972,
and was multiplied in the laboratory.
The flies mate readily. Mated females require a 7 to 8
day gestation period. Mature flies were then dissected
under a binocular microscope, and the parasite maggots
placed on the host caterpillar with the aid of a camel hair
brush. These then penetrate into the host body. After 4 to
7 days feeding, four or more full-grown parasite larvae
emerge from a single host and form puparia. The pupal
period lasts for 7 to 10 days.
Out of 2,330 parasitised larvae of H. virescens, 3,408
puparia were obtained, and 2,225 adults (1,358 males and
867 females) were released in pigeon-pea plots. No
recoveries were made.

Fundella cistipennis (Dyar) (Lepidoptera : Pyralidae) is another
pod-borer of pigeon-peas. It also attacks the pods of beans
(Phaseolus spp.), cowpea (Vigna unguiculata), seaside bean
(Cannavalia maritima) and stinking bush (Cassia occidentalis).
The larvae also bore into the stems of V. unguiculata and C. oc-
The eggs are ovate, shallowly domed dorsally, flattened against
the substratum ventrally and chorion ornamented with a network
of elongated polygons. Whitish in colour when freshly laid, they
later assume a pinkish colour. They are laid singly on the buds,
flowers and young pods.
The larva is creamy-white, often tinged with pink, with a dark
brown head capsule. The newly hatched larva feeds outside the
pod for a few hours before boring into the pod, where it attacks
the developing seeds. Pupation usually occurs inside the pod
within a tough silken cocoon slightly projecting outside the pod.
The exposed portion of its cocoon is concealed by debris. The
total life-cycle lasts for 35 to 44 days.
The natural enemies recorded in Barbados are listed in Table 5.

TABLE 5. Natural enemies of Fundella cistipennis (Dyar), in Barbados.

Trichogrammatidae T. fasciatum Egg-parasite
Braconidae Bracon sp. Ecto-larval para.
Bethylidae Parasierola (=Perisierola)
sp. nigrifemur (Ashmead)
Tachinidae Stomatoimyia ipse Walker Larval parasite
Coccinellidae C. sanguine Preys upon eggs
and young larvae
Chrysopidae Chrysopa sp. do -
C. lanata do -
C. limitata do -

The populations of these natural enemies were usually too low
to provide adequate control.
Between 1968 and 1983 nine parasite species (six from CIBC,
Trinidad, and one each from India, St. Vincent and Antigua)
were obtained and released in pigeon-pea plots (see Appendix 2.)
From those nine species, only two parasites, vis. B. hebetor
from India and Bracon sp. prob. hebetor (= B. brevicornis) from
St. Vincent were recovered in the field.
The average levels of parasitism by B. hebetor were 8% in
1973, 1.3% in 1974 and 8% in 1975 and 1976; the highest level
of parasitism recorded at one locality was 46.6%.
Bracon sp. prob. hebetor, was first released in March 1983.
Between April and December 1983, the range of parasitism
recorded was 2.1% to 70% (average 16.9%).

Seed beetle Callosobruchus chinensis (Linnaeus) (Col-
eoptera : Bruchidae) has been recorded in the Greater and Lesser
The bruchid is a serious pest, attacking seeds in the field as well
as in storage. The larvae develop inside the dry peas and beans.
During these studies, out of 10,350 dry pods examined, 7,280
were infested by four species of Coleoptera and two of Lepi-
doptera. The most abundant of these was the bruchid.
The adult is about 3mm long, greyish-black with white mark-
ings and two raised ivory spots at the middle of the hind margin
of the prothorax.
The eggs are laid on the pods in the field or on the seeds in
storage, and hatch in 4 to 6 days. On hatching, the larvae bore in-
to the seeds. More than one larva can survive in a single seed and
they mature in about three weeks. Pupation occurs within the



seeds. The pupal stage lasts for 7 to 10 days, and the adults may
remain in the seed for three days or longer.
The main natural enemies recorded in Barbados were: Dinar-
mus vagabundus (Timberlake) and Zatropis sp. nr. bruchivorus
(Ashmead) (Pteromalidae).
During 1975 and 1976, two parasites, D. vagabundus and
Dinarmus basalis (Rondani) were received from the Indian Sta-
tion of CIBC. Of these, 2,211 adults of the former and 1,300 of
the latter were released in the field. Although a few recoveries
were made, it is not known if the parasite(s) were indigenous or

Minor Seed Pests
A few insects of minor economic value, found damaging the
seeds were: Brachyacmapalpigera (Wlsm.) (Gelechiidae), Cathar-
tus quadricollis (Guer.) (Silvanidae), Pityophthorus xylotrupes
(Eichhoff) (Scolytidae), Trogoderma anthrenoides (Sharp)
(Dermestidae), Loberus sp. (Languriidae) and Stilbus sp.


In Barbados, three pests, Heliothis virescens (F.), Fundella
cistipennis (Dyar) and Callosobruchus chinensis (L.) inflict
serious damage to pigeon-pea pods. Over the years it was
estimated they destroy some 60% of the pods annually.
Although a number of indigenous natural enemies were
recorded attacking eggs, larvae and pupae of these pests, their
populations were usually too low for adequate control.
Between 1968 and 1983, a number of parasite species were in-
troduced from India, Pakistan, Uruguay, U.S.A. and the Eastern
Caribbean islands; 17 for the control of H. virescens, nine for F.
cistipennis and two for C. chinensis. Of these, two, species,
Bracon hebetor (Say) from India and Bracon sp. prob. hebetor
(Say) (close to Bracon brevicornis [Wesmeal]) from St. Vincent,
became established against Heliothis and Fundella. The levels of
parasitism by the latter species was 3.9% to 44.4% (average
35.2%) on H. virescens and 2.1% 70% (average 16.9%) on F.
cistipennis, between April and December 1983.

APPENDIX 1. Exotic natural enemies introduced against Heliothis virescens (F.),
between 1968-83, into Barbados, W.I.

Natural enemy Country/ Year No.Relea- Status
origin introduced sed

Trichogramma achaeae Nagaraja India 1972 40,000 N.R.
and Nagarkatti
**Trichogramma chilotraeae India 1972-73 24,000 R.
Nagaraja and Nagarkatti
Trichogrammatoidea armigera India 1972, 1974
Nagarkatti and 1975 14,000 N.R.
**Campoletis chloridae Uchida India and 1968,1971-
Pakistan 72,1975 &
1982 2,280 R.
**Campoletis flavicincta Uruguay 1981-82 1,330 R.
(Ashmead) (through CIBC, (338 females
Trinidad) and 992 males)
Eriborus sp. India 1975 Figure not N.R.
***Apanteles marginiventris India and 1970 and 5,700 R.
(Cresson) Pakistan 1975
**Bracon hebetor (Say) India 1970 and 2,700 R.
***Bracon sp. prob. hebetor (Say) St. Vincent
(close to Bracon brevicornis
(Wesmeal)) 1983 12,000 R.
(lab. bred)
***Trichospilus diatraeae Cherian India 1972 25,000 R.
and Margabandhu (lab. bred)
Drino imberbis Wiedemann India 1968-70 1,580 N.R.
and 1975
Eucarcelia illota Curran India 1968-69 1,100 N.R.
Eucelatoria sp. India 1970 F.N.A. N.R.
Eucelatoria bryani Sabrosky Arizona 1972-73 2,225 N.R.
(USA, via (867 females)
CIBC, T'dad)
Exorista fallax Meigen India 1968 60 N.R.
Goniophthalmus sp. India 1968 15 N.R.
Rhinocoris marginatus Fab. India 1970-71 50 N.R.

R. = Recovered. N.R. = Not recovered
** = Recoveries not consistent. *** = Established permanently


APPENDIX 2. Exotic natural enemies introduced against Fundella cistipennis
(Dyar), between 1968-84, into Barbados, W.I.

Natural enemy Country/ Year Norele- Status
origin introduced ased

Bracon sp.
Bracon cajani Mues.


Bracon thurberiphagae (Mues.) Trinid.d

**Bracon hebetor (Say) India

***Bracon sp. prob. hebetor (Say) St. Vince
(very close to Bracon
brevicornis (Wesmeal))
Apanteles etiellae Viereck Trinidad
and St. K

and 1974
and 1974
1970 and
mnt 1983






1968-69 and 244 N.R.

Phanerotoma bennetti Mues. Trinidad 1969-70
Eiphosoma annulatum (Cresson) Trinidad 1968-70

Parasierola (=Perisierola)sp. Trinidad 1968

117 N.R.

394 Already
in B'dos

79 -do-

APPENDIX 3: Exotic natural enemies introduced against Callosobruchus
chinensis L., firing 1975-76, into Barbados, W.I.

Natural enemy Country/ Year No. rele- Status
origin introduced asked

Dinarmus basalis (Rondani)
Dinarmus vagabundus (Timb.)


1975-76 2,200 N.R.
1975-76 1,300 Alrea-
dy pre-

R. = Recovered N. R. = Not recovered
** = Recoveries not consistent *** = Established permanently


Control of Hartrot or Fatal Wilt of Coconut Palm

V. T. Alexander P. Kastelein
P.O.B. 160, Palm Research Center
Ministry of Agriculture
Paramaribo, Suriname, South America

Hartrot, or fatal wilt of coconut considered to be caused by
the constant association of flagellate Phytomonas in the
phloem of the diseased palm, is a potential danger affecting
the progress of the economically important palm culture in
Suriname and this region. In our attempts to control the
disease, the results of field experiments revealed that
periodical application of the insecticide Endrin around the
coconut palms and weed control in the coconut plantations,
checks the rapid spread of the disease. These indications on a

practical scale proved that the same Endrin treatment applied
only to the surrounding trees of a diseased palm, after killing
the affected palm as soon as initial symptoms are noticed, and
weed control in plantations where the disease was endemic
checks this disease more or less on a permanent basis after
about nine months of commencement of the treatment.
Keywords: Coconut; hartrot; fatal wilt; flagellates;
Phytomonas; control.

Hartrot or fatal wilt of coconut was first recorded in Suriname
by Drost (1908). This disease has been observed in both
economically important coconut and oil palms.. Now it is
widespread in South America and the Caribbean Region. In
1976, Parthasarathy et al. identified the flagellate Phytomonas in
the phloem of the diseased coconut palm. Since then the cons-
tant association of these flagellates with this disease has been well
This disease is characterized in coconuts by the yellowing of
leaves starting from the oldest and then progressively affecting
the younger ones. This is followed by dropping nuts; the im-
mature ones fall initially and are followed by the mature ones.
The next phase is a blackening of female flowers and browning of
the younger inflorescences. Finally, a rot of the spear takes place
and the spear leaf topples over emitting a foul smell. The apical
region also rots with a similar odour. The course of the disease,
from initial symptoms to the complete death of the plant, takes
place in a period of 6 to 12 weeks. There is no recorded case of
recovery after the initial symptoms occur. This disease has poten-
tial for rapid spread which endangers the palm industry of South
America and the Caribbean.
From research, mainly on applied aspects conducted in
Suriname for the last few years, we are able to identify preventive
measures to control the rapid spread of the disease in coconut
plantations. These measures have also been successfully extended
to farmers' fields. The basic aspects of the disease still remain to
be fully investigated.

Four different trials were conducted in experimental stations,
two of them with different chemicals and the other two by con-
trolling weeds. On a practical scale, trials were conducted in four
different locations, three of them in experimental fields and one
in a private farmer's holding.

Chemical Trials
The first trial in La Poule (PO 86), Endrin, Furadan and
Chestnut compound were used. The second trial in Jenny (VP
548), Endrin and Sevin were used.


Endrin 20% was applied at the rate of 80cc in 5 to 10 litres of
water once in two months to wet the soil around the base of the
tree in a circle whose circumference was m for the tree.
Furadan 5% granule, at a dose of 280g per tree, was applied
once in four months to the soil around the base of the tree in a
circle whose circumference was im for the tree.
Thirty grams of Chestnut compound was dissolved in a little
hot water and a solution was made with 9 litres of cold water and
used as a soil drench. This was also applied once in four months.
Sevin 85 %, at a rate of 6g per litre of water per palm, was sprayed
on the crown once in three months.
Untreated palms were included in both experiments which
were laid out in a randomized block design. The treatments were
replicated six and five times in the first and second experiments,
respectively. The first trial commenced during May 1979, and
after 20 months of experimentation the results were analysed.
The second experiment was started in October 1979 and ended in
March 1983 when the results were reviewed.

Weed Control Trials
The first trial in La Poule (PO 86) was started in May 1979, and
the results were checked after 20 months. The second in Jenny
(VP 599) started in May 1980, and the results were analysed at
completion in September 1983.
Weed control was done either by hand or herbicides whenever
necessary to keep the area completely free of weeds. In non-
weeded control plots, only the tree circle was kept free of weeds.
In the four trials on a practical scale, the first in Brokobaka (BR
18) was conducted in 1979, the second in Coebiti (CO 40) in
1981, the third in a private field at Uitkijkpolder (VP 609) in
February 1983, and the fourth in Jarikaba (VP 596) in August
Regular observation for disease was made in all trials. In the
first two, application of Endrin was done as a soil drench around
the base of hartrot affected and surrounding non-affected palms
in every case of disease incidence. In the third and fourth
trials,the affected tree was killed by pouring undiluted Gramax-
one in three or four holes around the trunk of the palm as soon as
the initial symptoms were noticed. The bases of surrounding trees
were drenched with Endrin as in the previous case. In all these
trials weeding was practiced at regular intervals.


In the first chemical trial (PO 86) it is shown that among the
chemical treatments, application of Endrin significantly prevents
the spread of hartrot disease (Table 1).

TABLE 1. Incidence of hairot in coconut palms in trial one (PO 86) in different
chemical treatments.

Treatments lumber treated % dead

Bndrtn (Insecticide) 96 12
Furadan (lematictde) 96 41
Chestnut compound (Fungictde) 92 35
Control 88 44

++ Significant at 1% level L.S.D. = 21.5 for treatments

In trial 2 (VP 548), the Endrin treatment again proves to be
highly effective in controlling hartrot disease. In both the above
trials, Furadan, Chestnut compound and Sevin are not effective
and are similar to the controls (Table 2).

TABLE 2. Incidence of hartrot in coconut palms in trial two (VP 548) in Endrin
and Sevin treated plots.

Treatments lumber treated % dead

Endrin 43 7"'
Sevin 44 64
Control 40 70

++ Significant at 0.1% level L.S.D. 50 for treatments

The results of the first weed control trial (PO 86) indicate that
complete weed control in coconut plots is also very effective in
checking the disease (Table 3).

TABLE 3. Incidence of hartrot in coconut palms in weed control trial one (PO 86).

Treatments lumber treated % dead

Complete weed control 64 7"
1o weed control 60 62

+ Significant at 1% level L.S.D. = 2.5 for treatments


In the second weed control trial (VP 599), with similar
treatments as above, the results indicate that complete weed con-
trol in coconut gardens significantly decreases the incidence of
hartrot (Table 4).

TABLE 4. Incidence of hartrot in coconut palms in weed control trial two (VP 599).

Treatments lumber treated % dead

Complete weed control 52 36.5+
No weed control 54 51.4

+ Significant at 5% level L.S.D. = 11.1 for treatments

The results of several trials to control hartrot or fatal wilt of
coconut indicate the possibility of effective control of this malady
by applying certain chemical and cultural practices.
Among the chemicals, the insecticide Endrin significantly
reduced the incidence of the disease. This may be due to the type
of chemical, for Endrin is a chlorinated hydrocarbon, while Sevin
is carbamate insecticide. Furadan is also a carbamate compound
(Thomson, 1977) but used as a nematicide, and Chestnut com-
pound is fungicide. Endrin is more persistent in its effects than
Sevin and Furadan and may, therefore, better eliminate the vec-
tor or vectors involved in transmission of the disease. Further, En-
drin has been applied at more frequent intervals, i.e., once in
two months, Sevin once in three months and Furadan once in
four months. The ineffectiveness of Furadan and Chestnut com-
pound may be due to non-involvement of nematodes or fungi in
the cause of this disease. The vector, or vectors, and the infective
stage-like nymph may be confined to subterranean feeding on
the roots of grasses and coconut (Eden-Green, 1978), and thus
the frequent soil application of Endrin may have been more ef-
fective than Sevin applied on the crown.
This finding is quite in agreement with that of Lopez et al.
(1975) for controlling 'Marchitez sorpresiva,' a wilt disease of oil
palm in Colombia associated with Phytomonas sp., a sieve
restricted protozoan flagellate, by Endrin application. Further,
Desmier de Chenon (1984), who suspects Lincus StMl. as the
possible vector, mentioned that this species does not appear
capable of flying and is mainly terricolous. Thus, when both
nymphae and adults move down the stem after the appearance of
the first disease symptom on the palm, they pass through the cir-
cle treated with Endrin and the insecticide becomes effective
against them.
Similarly, weed control also is effective in controlling the
disease. The role of weeds in the etiology of the disease is not
clear yet. They may serve as host plants for the pathogen, pro-
bably Phytomonas staheli (Kastelein et al., 1984). Weeds may
provide the natural habitat for the vector or vectors (Griffith,
1980). The presence of weeds may have some beneficial
physiological effects on the flagellates in the palms, especially in
the roots. Thus, by removing these, better control of the disease
is obtained.
In practical application of these results, it has been found that
a combination of Endrin application and weed control more or
less permanently stops this disease in areas where it was endemic.
In this case, Endrin is applied only to surrounding trees of an in-


In the first trials on practical application, 123 out of 608 bear-
ing palms died of hartrot in the period from 1975 to 1979. The
treatments were started in early 1979, and there were no new
cases after the end of that year.
In the second trial with 240 coconut palms, the hartrot in-
cidence was as follows:


Number of trees
died of hartrot


In this case, the treatment was started late in 1981 and was con-
tinued when a fresh case was noticed. As the results indicate,
there was a sharp decline in the incidence of hartrot after the
commencement of the treatment and finally the disease disap-
In the third trial in a cultivator's field, the results were as

fected palm. Thus, the amount of the insecticide used and the
number of times applied is very much reduced. This saves both in
the cost and risk involved. Similar results have been reported for
oil palm in Colombia, where a combination of weed control and
insecticide spraying reduced 'Marchitez sorpresiva' from 53%
(control) to 2 %, while weed control alone reduced the disease in-
cidence to 13% and insecticide application alone to 35% (Mena
et al., 1975).

Although these results are of special significance at this junc-
ture, research must be continued to identify safer methods and
chemicals which can be used to control the disease. Further
research must be able to specify cultural and serological methods
for identification of the pathogen, determination of the vector(s)
and proof of pathogenicity through Koch's postulates.

January 1983
February '83
March '83
April '83
May '83
June '83
July '83
August '83
September '83
October '83
November '83

Number of
trees affected


Thus of 398 bearing palms, 44 (11%) were lost due to the
disease through October 1983. Nine months after commencing
the treatment in February 1983, the disease ceased to occur in
that field.
In the fourth trial, in an experimental field using 280 four-
year-old palms, the disease first started in August 1983 on one
tree and the first treatment was given. In March and April 1984
two and one more palm were affected respectively, and the treat-
ment was repeated. Since then there were no new cases.

Thanks are due to Mr. M.A. Palmtak for his invaluable assistance in the field.
1. Desmier de Chenon, R. 1984. Research on the genus Lincus Stal, Hemiptera
Pentatomidae Discocephalinae and its possible role in the transmission of Marchitez
of oil palm and Hart-Rot of coconut. Olkagineaux 39(1):1-6.
2. Drost, A.W. 1908. Jaarverslag over 1907. Insp. Landb. Surin. 19-20.
3. Eden-Green, S.J. 1978. Rearing and transmission techniques for Haplaxius
sp. (Hom. Cixidae), a suspected vector of lethal yellowing disease of coconuts. Ann.
appl. Biol. 89:173-176.
4. Griffith, R. 1980. The transmission of micro-organisms associated with
Cedros wilt of coconut. J. Agric. Soc. of Trinidad and Tobago LXXX(4):303-310.
5. Kastelein, P., C. Karyosemito, and P. Segeren. 1984. The role of weeds in
the incidence of'hartrot' or 'fatal wilt' of palms: III. Enumeration of weeds as host of
the protozoa Phytomonas (Trypanosomatidae) and attempts of culturing the
flagellates. De Surin. Landb. 32(1):25-42.
6. Lopez, G., P. Genty, and M. Ollangnier. 1975. Control preventive de la
'Marchitez sorpresiva' del Elaeis guineensis en America Latina. Olagineux
7. Mena, E., C. Cardona, G. Martinez, and O.D. Jimenez. 1975. Oil palm
sudden wilt. Rev. Colomb. Ent. 1,1.
8. Parthasarathy, M.V., W.G. van Slobbe, and C. Soudant. 1976.
Trypanosomatid flagellates in the phloem of diseased coconut palm. Science
9. Thomson, W.T. 1977. Agricultural chemicals. Book I. Insecticides. Thom-
son publications. P.O. Box 7967. Fresno, CA 93727.


Use of Open Versus Closed Systems in

Caribbean Prawn Hatcheries

Dallas E. Alston
Department of Marine Sciences
University of Puerto Rico-Mayaguez Campus
Mayaguez, PR 00708 USA

The culture ofMacrobrachium rosenbergii, the giant Malay-
sian prawn, has led to Caribbean culturists starting hatcheries
to produce postlarvae as stock. Two systems are primarily
employed: open, which utilize continuous or batch exchange
of water, and closed, which recirculate the water. Open
systems are generally safer since water exchanges can be made
as needed. A disadvantage of open systems is that the hatchery

El cultivo de Macrobrachium rosenbergii, el camar6n
gigante de Malasia, ha obligado a los cultivadores del Caribe a
empezar sus propios criaderos para la producci6n de postlarvas
para la cria. Los sistemas abiertos y cerrados son los dos prin-
cipales metodos usados. Los sistemas abiertos utilizan flujo
continue del agua o cambios frecuentes de esta. La ventaja de
este sistema esta en el poder eliminar aguas contaminadas

Mrcrobrachium rosenbergii, the giant Malaysian prawn, has
become an increasingly important culture organism in the Carib-
bean region. Currently, there are prawn farms in Costa Rica, the
Dominican Republic, Honduras, Jamaica, Martinique, Panama,
and Puerto Rico. Most of the culturists prefer to establish a local
hatchery to produce their own stock of postlarvae since importa-
tion on a large scale is prohibitive.
Macrobrachium hatcheries require brackish water with
salinities ranging from 12 to 19 ppt. Two systems are primarily
employed: open, which utilize continuous or batch exchange of
water, and closed, which recirculate the water. There are many
designs and methods for culture. The choice of a suitable system
should be determined by the availability of a good water source,
the distance from the hatchery to the growout ponds, and the in-
itial investment.

Open Systems
Open systems are often a logical choice for the majority of
prawn hatcheries since the initial investment is often lower than
for closed systems. A good supply of uncontaminated fresh and
saline water is needed. The site of the open system thus
necessitates that the hatchery be located near a saline water
source, since considerable amounts of water are used in con-
tinuous or batch exchanges of water.
The intensive labor involved in the culture of the larvae results
in considerable capital input during the culture period. However,
if problems arise during the culture, an open system provides for
complete exchange of the culture water, a practice which may
often save the larvae.
The hatchery should have a total water storage of at least dou-
ble the larval tank volume. This capacity allows for adequate
water storage for the mixing of the brackish water and provides
space for storing postlarvae before distribution to ponds (New
and Singholka, 1982).


Fernando Ibanfez
Aquaculture Enterprises, Inc.
Call Box 5000 Caja 449
San German, PR 00753 USA

must be located sufficiently near a source of saline water.
Closed system hatcheries can be situated far from the coast,
since the addition of both fresh and saline water is minimal.
Disadvantages of closed systems are the higher initial costs and
difficulty in eliminating contaminated waters.

en un moment determinado. Los sistemas cerrados recirculan
el agua. Los criaderos de sistema cerrado pueden ser instalados
lejos de la costa, ya que el uso de agua dulce y salada es
minimo. Las desventajas de este sistema se deben al incremen-
to del costo inicial y al problema de deshacerse del agua de
cultivo cuando surgeon problems. Los sistemas abiertos
utilizan cambios continuous de agua o en poca cantidad.

Surface water should be filtered before use in the hatchery.
The filtration process should include a sand filter and then a
smaller mesh filter near the mixing tank (New and Singholka,
1982). Tap water can often be used without filtration, since most
of the water has been treated for human use. Care must be taken,
however, to remove the residual chlorine from the water.
Ideal sites would be where the wells could be drilled to various
depths to either saltwater or freshwater strata (New and
Singholka, 1982). This could be done along the coast where salt-
water intrusion occurs and forms a wedge beneath the freshwater
strata. Care must be taken if surface water supplies for fresh or
saltwater are to be used. These waters are subject to contamina-
tion and salinity variations. If the hatchery location requires use
of surface water, the water should be carefully checked for
pesticides (New and Singholka, 1982).
Other water quality parameters should also be monitored.
Prawn larvae require water of extremely high quality because they
are particularly susceptible to toxic ammonia, and to bacterial
and fungal infections (Aquatic Farms, 1979). Postlarvae are
especially susceptible to nitrite and nitrate, both in terms of acute
and chronic toxicity (New and Singholka, 1982). Sublethal effects
of nitrite at levels as low as 1.8 ppm with prawn larvae have been
reported. Reports are that hardness of less than 100 ppm CaCO3
are suitable for freshwater (New and Singholka, 1982).
Two techniques of open systems are generally employed in
prawn hatcheries. These two methods have been described by
Aquatic Farms (1979) as follows:
Green Water Method
Phytoplankton is cultured in separate tanks to precondition the
water prior to introduction into the larval rearing tanks. Every
other day, the phytoplankton-rich water is used to replace 50 to
75% of the volume in the larval tanks. With this method, the
phytoplankton continuously "condition" the water (presumably
by taking up the metabolic wastes of the larvae and other food
organisms), and shade the larvae from strong sunlight.


Partial Change (or Clear Water) Method
This practice involves utilizing continuous or batch exchanges
of clear water in the larval tanks. With this technique, 75% or
more of the waste is exchanged daily, either by continuous
flushing or by a daily rapid purge, and the accumulation of toxic
metabolites in the larval tanks is prevented without the necessity
of culturing phytoplankton. However, the water usually requires
pretreatment or conditioning and the larval tanks must be shaded
from direct sunlight.
A major disadvantage of the open system is the necessity of an
adequate supply of both fresh and saline water. Thus, care must
be taken to insure that the water sources will remain uncontami-
nated. If water is not of suitable quality, considerable expense to
treat the water for hatchery use may incur. Pumping costs may
also be high. Another disadvantage of an open system is that the
hatchery might be located far from the growout facility.

Closed Systems
Closed system hatcheries can be situated far from the coast,
since the addition of both fresh and saline water is minimal.
Closed systems are useful in areas with freshwater and energy
shortages (New and Singholka, 1982). Such systems usually in-
volve filters and other water quality improvement apparatus to
improve the quality, so construction expense may be higher.
Seawater is usually transported to the hatchery site. This opera-
tion is costly, so water conservation is essential in the system. Ar-
tifical seawater has been used but this practice is usually expen-
sive (New and Singholka, 1982). Most closed systems, however,

still need a 25% exchange of their water each week. This is
because of the buildup of nitrate, which is the least toxic end pro-
duct of nitrification, but which can still affect larvae when in high
An innovative use of brine water from salt ponds has been
reported by Tunsutapanish (1980a; as reported by New and
Singholka).The use of brine reduces the amount of water that has
to be transported to the hatchery. The brine can be diluted at the
hatchery. The water from salt ponds contains few or no
pathogenic organisms. However, more research is needed before
this source is utilized extensively. Dunaliella salina, a green algae,
is frequently present in these salt ponds. The effect of this algae
on prawn larvae is unknown.

Open and closed systems have both advantages and disadvan-
tages. Open systems are safer, since the contaminants can be
washed out. Closed systems are also designed to remove con-
taminants, but the use of filters and other water quality ap-
paratus becomes necessary. The location of either system should
take into consideration the effects from hurricanes or other
tropical storms prevalent in the Caribbean.

1. Aquatic Farms, Ltd. 1979. Multiple-use options for a prawn hatchery on
Guam. Prepared for the Government of Guam, Department of Commerce, Project
Number 07-6-02028.
2. New, M.B. and S. Singholka. 1982. Freshwater prawn farming. A manual
for the culture ofMacrobrachium rosenbergii. Food and Agriculture Organization of
the United Nations, Fisheries Technical Paper Number 225.



Developing Pest Management Strategies

for Small Farmers

Based on Traditional Knowledge

Miguel A. Altieri
Division of Biological Control
University of California, Berkeley 94720

For centuries traditional farmers have kept pest damage
within acceptable levels by employing a wide variety of
cultural practices based on local lore and resources. One such
practice is the use of polycultures. Factors involved in pest
regulation in polycultures include: increased parasitoid/pre-
dator populations, available alternative prey/hosts for natural
enemies, decreased colonization and reproduction of pests,
feeding inhibition or repellency from non-host plants and
prevention of movement and emigration. These elements of

natural pest control built into small farming systems should be
examined, so that the valuable ones are retained in the course
of agricultural modernization. Thus, traditional knowledge
must be considered to guide changes and attain optimum
yields in regions with low-input agriculture. All development
approaches should be village-based, with emphasis on self-
sufficiency, use of local resources and indigenous agricultural

Traditional farming systems represent centuries of accumu-
lated experience of interacting with the environment, by farmers
without access to scientific information, external inputs, markets,
capital, institutional services and high quality natural resources
(de Janvry, 1981). Such skills, using locally available energy and
materials, have often translated into farming systems with sus-
tained yields (Wilken, 1977; Egger, 1981). Western agricultur-
alists, however, often have curious perceptions of these systems
and their productivity potential, considering small farms to have
low productivity. Therefore, obtaining "bigger yields" becomes
the goal, and the justification for claiming the necessity of
technology transfer and institutional innovation (Alverson,
1984). Although productivity per unit of land may seem low,
peasants may obtain a high level of productivity from other
resources that are scarcer or more essential. Little attention is paid
by researchers to the ecological context and cultural organization
of agriculture. Not surprisingly, few significant technological
packages, capable of yielding increased net returns, have been
successfully offered to the majority of peasants (deJanvry, 1981).
Improvement of peasant income by increasing agricultural pro-
duction through the use of expensive purchased inputs may no
longer be appropriate. Alternatively, what may be more ap-
propriate is to promote strategies centered on self-sufficiency in
production, so that the dependency of peasants on costly inputs
and industrial technology is minimized. To develop such systems,
traditional "know-how" must be assessed to guide the use of
modern agricultural science to progressively and carefully im-
prove the productivity of small farming systems. Such
assessments have gradually increased in the last decade (see
Altieri, 1983, and references cited therein) and many of them
have provided the basis for successful rural development projects.
An example is the development of alley cropping in Nigeria, in
which selected leguminous trees and shrubs are planted in
association with food crops to accelerate soil-nutrient regenera-
tion, thus shortening the fallow period required for shifting
cultivation (Wilson and Kang, 1981). Another example is the
replacement of the traditional lucerne undersown in barley fields
of the Bolivian highlands with vetch (Vicia villosa) to increase
forage production after the grain harvest (Augstburger, 1983).
Evaluations of the dynamics of insect, weed, and pathogen
populations and of the methods of pest control commonly used
in traditional farming systems are few. The scattered information
of pests in subsistence agriculture is mostly of an anthropological
nature and does not provide quantitative details about the effects


of various cultural control practices on pest dynamics or about the
ecological mechanisms involved in the regulation of specific pests
(Matteson et al., 1984). Most of our understanding about the ef-
fects of crop diversity on pest incidence derives from experimental
measurements often obtained in isolation from the total context
of farming systems and of social reproduction.

Pest Management in Traditional Agriculture
The magnitude of pest problems in traditional agriculture is in
part a matter of perspective, because subsistence farmers may
have low yield expectations and tolerate relatively high pest losses
(Brown and Marten, 1984). Pests are tolerated because they are
either regarded as fellow creatures entitled to a share of the crop,
or merely because certain animal or plant "pests" are used for
food or other purposes. Many weeds are used by farmers as food,
medicine, animal fodder, fuelwood, etc. (Datta and Banertee,
1978). In fact, peasants in tropical Mexico manage a "nonweed"
concept; non-crop plants are classified according to use potential
and complementary positive effects on the one hand, and
negative effects on soil, pests and crops on the other (Chacon and
Gliessman, 1982).
Some traditional cropping systems exhibit built-in pest sup-
presssion mechanisms resulting from the integrated interaction of
factors such as:
1. arrangement of crops in time and space;
2. composition and abundance of non-crop vegetation within
and around fields;
3. species and genetic diversity of crops;
4. soil characteristics;
5. the surrounding environment; and
6. the type and intensity of cultural management.
Pest populations may fluctuate depending on their degree of
association with one or more of the vegetational components of
the system or their sensitivity to change in crop patterns, soil
management, etc. Although pest losses in traditional agriculture
can reach 40% (Brown and Marten, 1984), these losses fall in the
same range in modern agriculture, despite its use of chemical
pesticides. When pesticides are removed from modern systems,
losses can often approach 100% (Schwartz and Klassen, 1981).
Conversely, in traditional systems, pest damage is kept within
certain bounds by a variety of management practices based on
locally available resources.
Temporal and spatial crop diversity which characterizes tradi-
tional polycultures often results in lower pest incidence. The fac-


tors and mechanisms involved in this regulation are the subject of
active research (see Risch et al., 1983; Altieri and Letourneau,
1982, and references cited therein). For example, paddy rice
systems of southeast Asia are characterized by high genetic diver-
sity, which confers at least partial resistance to pest attack.
Farmers exchange seeds because they observe that any particular
variety tends to accrue pest problems if grown on the same land
for several years (King, 1927). In the Andes, farmers grow as
many as 50 distinct varieties of potatoes in their fields. The
maintenance of this wide genetic base is adaptive since it reduces
the threat to crop loss due to pests and pathogens which are
specific to particular strains of the crop (Brush, 1982). The clear-
ing of comparatively small plots, typical of shifting cultivation, in
a matrix of secondary forest vegetation permits easy migration to
the crops of natural control agents from the surrounding jungle.
Shade from forest fragments still standing in new fields reduces
shade-intolerant weeds and provides alternate food and shelter
for beneficial insects (Matteson et al., 1984).
These built-in pest suppressive mechanisms are complemented
by environmental manipulations conducted by farmers as part of
their farming operations. Thus farmers, in addition to inter-
cropping and use of resistant varieties, utilize cultural practices
such as crop rotation, synchronous planting, increased seeding
rates and changing time of planting (Litsinger et al., 1980). For
example, Pangasinan farmers in the Philippines planting mung-
bean after rice, often sow at increased densities and delay plan-
ting for one or two months to avoid flea beetles during the early
growth stages. Sowing of cowpeas into standing rice stubble in-
terferes with host finding by bean flies, thrips and leafhoppers.
Many farmers also place branches of plants (Glaricidia sepium
and Cordia dichtoma) within or beside the fields as pest
repellants (Litsinger et al., 1980).
In China peasants utilize a variety of cultural practices to con-
trol diseases in rice and wheat. Stripe rust of wheat is kept under
control by utilizing local varieties, postponement of sowing
winter wheat to reduce the chance of autumnal infection, increas-
ed frequency of irrigation and eradication of wheat ratoons.
Fusarium is reduced in wheat by avoiding the use of fertilizers of
high nitrogen content and proper water management (Chiu and
Chang, 1982).
In shifting cultivation systems, weeds can be controlled by
farmers provided that weed densities are relatively low and fallow
periods long. Long fallow periods effectively suppress annual
grasses and troublesome perennials. Burning can delay the need
for weeding up to five weeks after planting, while weeding is
recommended within two weeks after planting in unburned crop-
lands (Akobundu, 1980). In tropical Mexico, farmers utilize a
legume cover crop (Stizilobium sp.) in the off-season to smother
weeds (Gliessman, pers. comm.). The adoption of cropping pat-
terns which provide rapid canopy cover minimize weed competi-
tion. Intercropping short season crops such as maize and melon
with longer season crops such as corn and cassava can help prevent
buildup of weed species.
Improving Pest Control Systems
Procedures for determining appropriate technologies for small
farmers through the farming systems approach (Shaner et al.,
1982) have been adapted to develop insect-control recommenda-
tions by IRRI's scientists (Altieri, 1984). The methodology in-
1. understanding farmers' current perceptions of pests, insect
control practices and resources available for control;
2. determining yield losses for each crop growth stage;
3. matching key pests to measured yields;
4. selecting appropriate insect-control technology;
5. testing the technology on farmers' fields over several years;

6. evaluating the costs and returns of the technology.


So far the methodology has centered around the quantification of
yield losses for each growth stage of the crop by successively om-
mitting insecticide protection during each stage, while providing
control in the others. Results of these trials provide information
on the correct timing of insecticide applications. It does not pro-
vide an idea of insect dynamics and damage at various growth
stages when using farmers' management, thus excluding those
farmers who wish to maintain their traditional management and
those who cannot afford purchase of inputs (Altieri, 1984).
Researchers at IRRI recognize that no matter how strategies of
chemical pest control are approached, farmers will have to spend
more money (Litsinger et al., 1980). Given the economic cir-
cumstances facing developing countries (i.e., external debt,
transportation costs, international commodity price fluctuations,
etc.) effective non-chemical means of pest control, both in-
novative and traditional, should be thoroughly explored and
preferred: resistant crop varieties, augmentation and conservation
of natural enemies, cultural control, natural botanical insec-
ticides, microbial pesticides, etc. (Matteson et al., 1984).

Management Possibilities
Polyculture management is basically the design of spatial and
temporal combinations of crops in an area. There are many pos-
sible crop arrangements and each can have different effects on
insect, weed and pathogen populations. For insects, the attrac-
tiveness of crop habitats in terms of size of field, nature of
surrounding vegetation, plant densities, height, background col-
or and texture, crop diversity, weediness, etc. are subject to
In intercrop systems, the choice of a tall or short, early- or late-
maturing, flowering or non-flowering companion crop can
magnify or decrease the effects on particular pests (Altieri and
Letourneau, 1982). The inclusion of a crop that bears flowers dur-
ing most of the growing season can condition the buildup of
parasitoids, thus improving biological control. Similarly, the in-
clusion of legumes or other plants supporting populations of
aphids and other soft-bodied insects that serve as alternate
pre/hosts can improve survival and reproduction of beneficial in-
sects in agroecosystems. The presence of a tall associated crop such
as corn and sorghum may serve as a physical barrier or trap to
pests invading from outside the field. The inclusion of strongly
aromatic plants (i.e., onion, garlic, tomato, etc.) can disturb
mechanisms of orientation to host plants by several pests.
The date of planting of component crops in relation to each
other can also affect insect interactions in these systems. An
associated crop can be planted so that it is at its most attractive
growth stage at the time of pest immigration or dispersal, divert-
ing pests from other more susceptible or valuable crops in the
mixture. Planting of okra to divert flea beetles (Podagria spp.)
from cotton in Nigeria is a good example (Perrin, 1980). Corn
planted 30 and 20 days earlier than beans reduced leafhopper
population on beans by 66% compared with simultaneous plant-
ing. Fall armyworm damage on corn was reduced by 88% when
beans were planted 20-40 days earlier than corn, when compared
to the simultaneously planted intercrop (Altieri and Letourneau,
We still understand little of how spatial arrangements (i.e.,
row spacings) of crops affect pest abundance in intercrops. For ex-
ample, it has been noted that there is a greater reduction in
damage to cowpea flowers by Maruca testulalis in intra-row rather
than inter-row mixtures of maize and cowpea (Matteson et al.,
1984). Selection of proper crop varieties can also magnify insect
suppression effects. In Colombia, lower whorl damage by
Spodopterafrugiperda was observed in corn associated with bush

beans, than in corn mixed with climbing beans. In the same
trials, maize hybrid H-207 seemed to exhibit lower Spodoptera


damage than H-210 hybrid, when intercropped with beans.
Clearly, much further work is needed before appropriate crop
mixtures and row spacings are to be achieved.
The manipulation of weed abundance and composition in in-
tercrops can also have major implications on insect dynamics
(Altieri, 1983). When weed and crop species grow together, as it
is commonly observed in traditional cropping systems, each plant
species hosts an assemblage of herbivores and their natural
enemies, thus trophic interactions become very complex. Many
weeds offer important requisites for natural enemies such as alter-
nate prey/hosts, pollen or nectar as well as microhabitats which
are not available in weed-free monocultures. Relevant weeds that
support rich natural enemy faunas include the perennial stinging
nettle (Urtica dioica), Mexican tea (Chenopodium ambrosioides),
camphorweed (Heterotheca subaxillaris) and goldenrod (Solidago
altissima) (Altieri and Whitcomb, 1979). In the last 20 years,
research has shown that outbreaks of certain types of crop pest are
more likely to occur in weed-free fields than in weed-diversified
crop systems. Crop fields with a dense weed cover and high diver-
sity usually have more predaceous arthropods than do weed-free
fields. Ground beetles, syrphids, lady beetles (Coccinellidae) and
other predaceous insects are especially abundant in weed-diversi-
fied systems. Relevant examples of cropping systems in which the
presence of specific weeds have enhanced the biological control of
particular pests can be found in Altieri and Letourneau (1982).
These observations suggest that selective weed control may
change the mortality of insect pests caused by natural enemies.
The ecological basis for obtaining crop-weed mixtures which
enhance insect biological suppression awaits further development.
In traditional agroecosystems, the dispersion of crop plants in
species rich or genetically diverse mixtures restricts the spread of
pathogens. Such diversity gives a measure of stability in that the
failure of some species or genotypes due to diseases may be com-
pensated by the improved performance of others (Thresh, 1982).
Proper inclusion of immune or resistant crop plants in the mix-
tures can impede pathogen spread and increase the separation
between susceptible plants. Growing of tall plants together with
shorter crops can significantly decrease the spread of diseases by
either acting as a barrier to the free spread of propagules or by in-
terfering with the movement of insect vectors. For example, in
Japan, radish mosaic decreased when radishes were sown between
rows of rice, and pigeon peas in Haiti were protected from virus
diseases when grown between rows of tall sorghum (Palti, 1981).
There is also evidence that some plant mixtures adversely affect
nematode populations. Marigolds (Tagetes spp.) offer great
potential for nematode reduction through toxic action in inter-
crops (Visser and Vythilingam, 1959). Intercropped Crotalaria,
itself susceptible to nematode attack, diverts nematodes
(Radopholus similis) from other crops and then interferes with
the nematode life cycle within its roots (Palti, 1981).
Although traditional intercropping appears to offer con-
siderable potential as a means of increasing crop dominance over
weeds, there is much room to improve the effectiveness of weed
control in intercrops by manipulating crop diversity, spatial ar-
rangement, soil fertility, relative proportions of component
crops, and use of competitive cultivars. In shifting cultivation
systems, the natural regeneration of forest vegetation can be
replaced by a legume cover crop such as Psophocarpuspalustaris,
Centrosema pubescens and others which provide excellent
vegetation cover to the exclusion of weeds (Akobundu, 1980).
Similarly, weeds can be effectively suppressed in intercropping
systems by the use of low-growing crops (i.e., melon and sweet
potato) which quickly shade the soil surface thus minimizing
weed growth. Legumes intersown between maize rows offer the
opportunity for improving soil fertility, crop yield and weed con-
trol on otherwise impoverished soils of the humid tropics
(Akobundu, 1980). Crop density can be easily manipulated to

promote crop dominance over weeds in intercrops. Highest Com-
bined crop yields and the greatest degree of weed suppression
were obtained from a sorghum/pigeon pea mixture with a nor-
mal density of pigeon pea sown with a twice normal population
of sorghum (Shetty and Rao, 1981).

Extension of Appropriate Pest Management Practices
to Small Farmers
Generally in developing countries, the extension approach
consists of researchers developing recommendations, preferably
with continuous suggestions and critical input from farmers via
the extension service. Thus, extension agents are the principal
link between researchers and farmers. They reach farmers
through demonstrations, training courses, follow-up visits, often
with local pilot farmers as examples and demonstrators for others.
Seeds, pesticides, equipment, subsidies, credit, etc. are part of
the "package deals" and must be available at the proper time and
at an accessible place (Matteson et al., 1984). So far, the few
technological breakthroughs made in peasant farming, have in-
evitably been accessible to those peasants of recognized ability
and to those most favored in terms of control of resources and ac-
cess to markets, roads and credit (de Janvry, 1981). Moreover,
due to the heterogeneity of peasant farmers, global recommenda-
tions have proven to be seriously unfit for the majority of small
farmers who are usually confined to marginal areas. Thus, the
recommendations have only been, confined to accommodated
peasants that enjoy better soils, natural resources, and institu-
tional support.
If rural development is indeed successful among small farmers,
technical and organizational strategies must emphasize:
1. improvement of use-efficiency of local resources;
2. minimization of dependency on purchased inputs and in-
dustrial technology;
3. satisfaction of self-sufficient production; and
4. organization of peasants to enhance their cooperation for
economic and social survival.
There are several non-profit groups in the developing world em-
phasizing the "bottom up" or "grassroots" approach to rural
development. These groups, meagerly funded and isolated from
the mainstream agricultural colleges and ministries, have an
ecological vent relying on resource conserving technologies that
promote nutrient cycling, natural pest control and soil conserva-
tion (Altieri, 1983). The establishment of modular systems in
Tabasco, Mexico (Gliessman et al., 1981) and of improved high
land cropping systems in Bolivia (Augstburger, 1983) are suc-
cessful examples. The establishment of a self-sufficient ex-
perimental small farm (0.5 ha.) in Chile (CET, 1983), where
most of the food requirements of a family of scarce capital and
land can be met, has had great impact. Groups of peasants com-
ing from local and distant areas live in CET's farm for variable
periods of time, learning through direct participation in the far-
ming operations, all the organic production practices (i.e., com-
posting, raised beds, intercropping, etc.), farm designs, planting
dates, proper varieties, etc. After their training farmers are given
a basic package of seeds and then return to their communities to
teach their neighbors the new methods, and thus apply the
model in their own lands.
In the Peruvian Andes, "Grupo Talpuy" has been rescuing and
recording the knowledge of local farmers about farming practices
(i.e., mixed cropping, use of potato varieties, crop rotations, fer-
tilization, etc.), traditional crops utilized, use of non-crop plants,
etc., which is then synthesized and later disseminated in written
form (a low cost magazine called Minka) throughout the rural
areas (Minka, 1981). Each issue treats a different subject (i.e.,
mixed cropping, Andean crops, local herbal medicine, soil con-
servation, agricultural tools, low-cost house construction, etc.) in
a very simple manner, illustrated with a number of drawings and



graphics. The idea is that many efficient technologies have
originated and are used in very local areas, and can be extended
to other farmers in remote areas through the distribution of the
magazine. The objective is to make resources, and particularly the
resource of knowledge, widely available. Minka emphasizes the
use of resources that are locally available and that do not require
specialized knowledge for their control. In this way, farmers can
be selective in choosing technologies or practices that have
worked for other peasants that share similar levels of capital, land
base and natural resources.

It appears that there are several misconceptions in the highly
touted current view of traditional farming and the recipes for
making them "more productive." In a case study from small
farms in Botswana, Alverson (1984) convincingly shows that
many of the views on small farms are seriously flawed and
ideologically motivated, and that technology transfer is both un-
profitable and destructive of numerous indigenous institutions.
He argues that there is great potential for increased production

within traditional agriculture as it is currently practiced, with
minor changes in crop management practices and farm organiza-
The few examples of grassroots, bottom-up rural development
programs currently undergoing in the Third World suggest that
the process of development and diffusion of appropriate
technologies for peasants must meet at least three criteria:
1. utilize and promote autochthonous technologies;
2. emphasize use of local and indigenous resources; and
3. be a self-centered, village-based effort with the active par-
ticipation of peasants.
The ensemble of traditional crop protection practices used by
small farmers represents a rich resource for modern workers seek-
ing to create pest management systems that are well-adapted to
the ecological and socio-economic circumstances of peasants.
Clearly, not all traditional crop protection components are effec-
tive of applicable, therefore modifications and adaptations may
be necessary, but the foundation of development should be in-
digenous. Evidence suggests that in traditional farming systems,
the critical factor in the efficient use of scarce resources and in the
lowering of risks is diversity (Harwood, 1979). Maintenance of
biological diversity in these systems should then be the founda-
tion of any pest management strategy.

1. Akobundu, 1.0. 1980. Weed control strategies for multiple cropping
systems of the humid and subhumid tropics, pp. 80-100 in Weeds and their control
in the humid and subhumid tropics. I.O. Akobundu (ed.). Inter. Inst. Trop.
Agric., Ibadan, Nigeria.
2. Altieri, M.A. and W.H. Whitcomb. 1979. The potential use of weeds in the
manipulation of beneficial insects. Hort. Science 4:401-405.
3. Altieri, M.A. and D.K. Letourneau. 1982. Vegetation management and
biological control in agroecosystems. Crop Protection 1:405-430.
4. Altieri, M.A. 1983. Agroecology: The scientific basis of alternative
agriculture. Division of Biological Control, Univ. of Calif., Berkeley. 162 p.
5. Altieri, M.A. 1984. Pest management technologies for peasants: a farming
systems approach. Crop Protection 3:87-94.
6. Alverson, H. 1984. The wisdom of tradition in the development of dry-land
farming: Botswana. Human Organiz. 43:1-8.
7. Augstburger, F. 1983. Agronomic and economic potential of manure in
Bolivian valleys and highlands. Agric. Ecosyst. and Environment 10:335-346.
8. Brown, BJ. and G.G. Marten. 1984. The ecology of traditional pest
management in southeast Asia. Working Paper. East-West Center, Honolulu,
9. Brush, S.B. 1982. The natural and human environment of the central
Andes. Mountain Research and Development 2:14-38.
10. Centro de Educacion y Tecnologia. 1983. La huerta campesina organic.
Inst. de Estudios y Publicaciones Juan Ignacio Molina, Santiago-Chile. 45 p.
11. Chacon,J.C. and S.R. Gliessman. 1982. Use of the "non-weed" concept in
traditional tropical agroecosystems of south-eastern Mexico. Agroecosystems 8:1-11.
12. Chiu, W.F. and Y.H. Chang. 1982. Advances of science of plant protection
in the People's Republic of China. Ann. Rev. Phytopathol. 20:71-92.
13. Datta, S.C. and A.K. Banerjee. 1978. Useful weeds of West Bengal rice
fields. Econ. Bot. 32:297-310.
14. deJanvry, A. 1981. The agrarian question and reformism in Latin America.
The Johns Hopkins Univ. Press, Baltimore. 311 p.
15. Egger, K. 1981. Ecofarming in the tropics-characteristics and poten-
tialities. Plant Res. and Develop. 13:96-106.
16. Gliessman, S.R., E.R. Garcia and A.M. Amador. 1981. The Ecological basis
for the application of traditional agricultural technology in the management of
tropical agro-ecosystems. Agroecosystems 7:173-185.

17. Harwood, R.R. 1979. Small farm development: Understanding and improv-
ing farming systems in the humid tropics. Westview Press, Boulder, CO. 160 p.
18. King, F.H. 1927. Farmers of Forty Centuries. Cape, London.
19. Litsinger,J.A., E.C. Price and R.T. Herrera. 1980. Small farmer pest control
practices for rainfed rice, corn and grain legumes in three Philippine provinces.
Philipp. Entomol. 4:65-86.
20. Matteson, P.C., M.A. Altieri and W.C. Gagne. 1984. Modification of small
farmer practices for better pest management. Ann. Rev. Entomol. 29:383-402.
21. Minka. 1981. Issues No. 5, 6, and 7. Grupo Talpuy, Huancayo, Peru.
22. Palti, J. 1981. Cultural Practices and Infectious Crop Diseases. Springer
Verlag, Berlin.
23. Perrin, R.M. 1980. The role of environmental diversity in crop protection.
Prot. Ecol. 2:77-114.
24. Risch, S.J., D. Andow and M.A. Altieri. 1983. Agroecosystem diversity and
pest control: Data, tentative conclusions and new research directions. Environ. En-
tomol. 12:625-629.
25. Shaner, W.W., P.F. Phillipp and W.R. Schmehl. 1982. Farming systems
research and development: guidelines for developing countries. Westview Press,
Boulder, CO. 414 pp.
26. Schwartz, P.H. and W. Klassen. 1981. Estimate of losses caused by insects
and mites to agricultural crops. In CRC Handbook of Pest Management in
Agriculture. D. Pimentel (ed.), 1:15-77. CRC Press, Boca Raton, FL.
27. Shetty, S.V.R. and W.R. Rao. 1981. Weed management studies in
sorghum/pigeonpea and pearl millet/groundnut intercrop systems-some observa-
tions. Pp. 239-248 in Proc. Int. Workshop on Intercropping. ICRISAT, Patanchew,
28. Thresh, J.M. 1982. Cropping practices and virus spread. Ann. Rev.
Phytopathol. 20:193-218.
29. Visser, J. and M.K: Vythilingam. 1959. The effect of marigolds and some
other crops on the Pratylenchus and Meloidogyne populations in tea soil. Tea
Quarterly 30:30-38
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Husbandry. Butterworths, London.



Small Farming Systems in

Las Cuevas Watershed, Dominican Republic

J. Alvarez
Food and Resource Econ. Dept.
University of Florida, B. Glade, FL

P.E. Hidebrand
Food and Resource Econ. Dept.
University of Florida, Gainesville, FL

J.A. Nova
State Secretariat of Agriculture
Santo Domingo, Dominican Republic

Farming systems in the watershed are described. Data were
gathered by a multi-disciplinary team during the summer of
1982. Sample size was 182. Farming systems identified were
(1) irrigated with a rice base, (2) rainfed with an annual crop
base and minor permanent crops, and (3) predominantly cof-
fee farms which were not studied in detail. Irrigated farming
systems consisted of sole crops of beans, peanuts and maize in
addition to rice. Rainfed systems consisted of both sole crops
and crop mixtures of beans, maize and pigeon peas. Predomi-
nant crop mixtures are beans-maize, beans-pigeon peas, and

beans-pigeon peas-maize. Peanuts are predominantly sole
cropped. Unique to these systems are: (1) the "convite"
system-a social form of labor sharing for harvest; (2) bean
trading between rainfed and irrigated systems to maintain
fresh seed; (3) peanuts to provide cash; available as a loan
from the processing plant. Rainfed systems and increasing
population pressures subject the watershed to high rates of soil
erosion and resulting siltation downstream.
Keywords: farming systems; crop systems; crop associations;

Most islands in the Caribbean are experiencing ecological prob-
lems of uncommon magnitude. Small territories and population
pressures are pushing farmers to marginally productive steep-
lands. The Dominican Republic is no exception. Antonini et al.
(1981) have summarized the problem in the following manner:
The Dominican Republic today is faced with serious prob-
lems of erosion due to the widespread practice of slash-
and-bum agriculture and the prevalence ofshallow soils on
steep slopes. Substantial amounts of top soil are lost due
to poor management practices and there results greatly
reducedsoil fertility and crop productivity ... As a conse-
quence of increasing population pressure and a depleting
resource base, the farm-pasture-fallow cycle is rapidly be-
ing shortened, the land's capability for sustained produc-
tivity is diminishing, andincreasingly more marginal lands
are being brought under cultivation and extensive use. The
results of this deterioration of the Dominican steeplands is
affecting not only farmers within the high watersheds, but
it is also influencing the government's ability to develop
and maintain water resources for meeting energy,
agricultural and human needs (p.4).
Solving these problems is no easy task. But it seems obvious
that knowing the resources and farming practices prevalent in
these areas provides a good starting point for developing conser-
vation policies. For that reason, this paper describes the farming
systems in Las Cuevas watershed of the Dominican Republic.
The results reported are part of a multi-disciplinary research ef-
fort sponsored by the State Secretariat of Agriculture of the
Dominican Republic, the Association of Caribbean Universities
and Research Institutes, and the University of Florida. The final
objective of this inter-institutional agreement was to develop an
integrated management and protection plan for Las Cuevas


The Study Region
Las Cuevas watershed is located on the southwestern flank of
the Cordillera Central and covers approximately 600 km2. An-
tonini et al. (1981, pp. 16-19) have described some of the region's
most important characteristics.
More than 80% of the watershed is mountainous with elevations
ranging between 2,200 and 2,800 m. Plateaus and interior
lowlands account for about 13%, while the rest of the area con-
sists of flood plains and river terraces.
Dry subtropical conditions prevail in the westernmost portion

where the average temperature is 24.5"C and the mean annual
rainfall is about 750 mm. These conditions exist in 12% of the
total area. A wet subtropical life zone covers 15% of the basin,
with more humid conditions but still irregular rainfall distribu-
tion. Some 52% of the area is characterized by low montane wet
forest, with irregular rainfall and periodic frosts. The very wet low
forest accounts for 18% of the area, where mean annual
precipitation is 55% higher than evapotranspiration. Finally, 3%
of the watershed is very wet montane forest in the eastern por-
tion, with average temperatures of 17.7"C and mean annual
precipitation of 1,750 mm. Frosts are more frequent and average
rainfall exceeds evapotranspiration by 60%.
The population of the watershed is 85 % rural and 15 % urban.
Population estimates for 1981 were 39,411 inhabitants, with an
average density of 65 persons per km2. The population is ex-
pected to double by the year 2,000.
About 7,000 families live in the study region. More than half
live in small rural settlements (100 to 2,500 persons) in the hills
or along the terraces and flood plains adjoining the Las Cuevas
river and its tributaries. The greatest number of families live in
isolated hamlets and small agricultural villages. One road con-
nects these villages with Padre Las Casas, the only urban center in
the area, and most interconnecting dirt trails become impassable
during the rainy season.


The study area was visited by a multi-disciplinary group in
March, 1982. All members were placed on small teams and a type
of "sondeo" following Hildebrand (1981) was conducted. The
results of this visit provided valuable input for developing a ques-
tionnaire which was pre-tested near the end of June. Once the
questionnaire was redesigned, the final interviews were con-
ducted during the month of July.
The relevant population used was 5,609 households existing in
Las Cuevas watershed according to the 1980 population census.
Systematic sampling methods as outlined by Mendenhall et al.
(1971) were used to draw the sample size. The key variable in the
design was the level of household income, and accuracy of the
systematic sample was based on the assumption of random
household income and the advantages of systematic sampling in
the field work (Mendenhall et al., 1971). From the total popula-
tion of 5,609 households, a sample of 286 was selected. Because
the survey was multipurpose, 104 sampled households did not
operate any agricultural enterprise. Thus, the final sample for
this study included 182 agricultural households.
For the purpose of this analysis, relevant classification criteria
were needed. Ruthenberg (1980) has outlined this need as
In the process of adopting cropping patterns andfarming
techniques to the natural, economic and socio-political
conditions of each location and the aims of the farmers,
more or less distinctfarm systems have developed. In fact,
nofarm is organized exactly like any other, but farmspro-
ducing under similar natural, economic and socio-institu-
tional conditions tend to be similarly structured. For the
purpose of agricultural development, and to devise mean-,
ingful measures in agricultural policy, it is advisable to
group farms with similar structural properties into classes.
It is important in this context that relevant classification
criteria are used and no single criterion allows the forma-
tion of meaningful classes (p. 14).
The cropping patterns and farming systems found in the water-
shed were analyzed by clustering the most important crops of the
watershed with homogeneous technology and characteristics. The
classification was based on relevant factors such as irrigated and
rainfed land, type of land preparation, type of planting, level of
input usage, yields and crop cycles.
The final classification of the farming systems included:
1. short-cycle sole crop systems on irrigated land (beans, rice,
peanuts and maize) or on rainfed land (beans, maize,
pigeon peas and peanuts);
2. short-cycle crop mixtures on rainfed land (beans-maize,
beans-pigeon peas and beans-pigeon peas-maize);
3. permanent sole crop system (coffee); and
4. permanent crop mixture system (coffee-bananas).

Both large and small farms are found throughout the water-
shed although half of them contain 3 ha or less land. Excluding
the nine largest farms with 64% of the area, average farm size is
about 5 ha. Slightly over half the farms had only one parcel; the
others were divided into two or three parcels (Table 1). Half the
land area is in pasture, forest or bush and only 10% is in annual
(short season) crops (Table 2).
Coffee is the most important crop and is sole cropped on 675
ha (Table 3). It is associated with bananas on another 71 ha and
with a mixture of other crops on 5 ha. Rice and peanuts are only
sole cropped, 78% of the beans are sole cropped, but only 18%
of the maize and 10% of the pigeon peas are grown alone (Table
4). The most important annual crop associations are bean-pigeon
pea, bean-pigeon pea-maize and bean-maize (Table 5).

TABLE 1. Land distribution by numbers of parcels on each farm and percentage of
total area in Las Cuevas watershed, Dominican Republic, 1982.

Farms Total area
Number of
parcels Number Percentage Ha. Percentage
1 100 55.0 941 36.1
2 67 36.8 967 37.1
3 15 8.2 697 26.8

Total 182 100.0 2605 100.0

TABLE 2. Land uses found in the 182 surveyed farms in Las Cuevas watershed,
Dominican Republic, 1982.

Classification Area (ha) of total

Short-cycle crops 255 9.8
Permanent crops (excluding
coffee and coffee-banana) 49 1.9
Coffee and coffee-banana 746 28.6
Fallow land 203 7.8
Pasture, forest or bush 1352 51.9

Total 2605 100.0

TABLE 3. Land use by sole crop systems in the 182 surveyed farms in Las Cuevas
watershed, Dominican Republic, 1982.

Percentage of total
Crop Area (ha) Including coffee Excluding coffee

Rice 23 2.4 7.8
Beans 181 18.7 61.6
Peanut 18 1.8 6.1
Maize 7 0.7 2.4
Pigeon pea 5 0.5 1.7
Coffee 675 69.7-
Other 60 6.2 20.4

Total 969, 100.0 100.0

TABLE 4. Land use by crops grownalone and associated in the 182 surveyed farms
in Las Cuevas watershed, Domincan Republic, 1982.

Area (ha) Percentage of crop
Crop Sole cropped Associated Sole cropped Associated

Beans 181 51 78.0 22.0
Maize 7 31 18.4 81.6
Pigeon pea 5 43 10.4 89.6
Coffee 675 71 90.5 9.5



sloping land. Soil loss is minimal for permanent crop systems
which are prepared and planted only once over many years. The
following sections describe these farming systems.

Short-cycle Sole Crop Systems on Irrigated Land
These systems are located on lowlands. The four crops rotated
include rice, beans, peanut and maize (Table 6).
Rice is planted once a year, maize and peanuts are planted
twice and beans three times. Land preparation is the same for the
four crops: with oxen and a plow. For 0.6 ha of rice, a nursery bed
of 10 m, where 45 kg of seed are broadcast, is prepared.
Although four major types of farming systems emerged from
the classification, this paper is concerned mainly with short-cycle
sole and associated crop systems on irrigated and on rainfed land.
The emphasis placed on these systems is related to soil conserva-
tion concerns. Short-cycle crop systems require land preparation
one to three times a year. This permits soil erosion when farming

TABLE 5. Associations of beans, maize and pigeon pea in the 182 surveyed farms in
Las Cuevas watershed, Dominican Republic, 1982.

Association Area (ha)

Bean-pigeon pea 17

Bean-pigeon pea-maize 16

Bean-maize 10

Other bean associations 8

Other pigeon pea associations 10
Other maize associations 5

Total bean associations 51

Total pigeon pea associations 43

Total maize associations 31

Rice transplanting by hand occurs one month after land
preparation. A seed drill with a mule is used to plant the other
three crops. Seed rates are about 73 kg ha- 1 for rice, between 73
and 87 kg ha I for beans and for peanuts and maize 73 and 22
kg ha 1, respectively.

Fertilization practices are absent in peanuts and maize.
However, from 145 to 363 kg ha I urea are applied twice to rice,
and urea or the formula 15-15-15 are used on beans at a rate of
between 73 and 254 kg ha .

Weeding is done with machetes in all four crops. No insec-
ticides are applied to either rice or maize. Beans receive an ap-
plication of insecticide mixed with liquid N, while powdered in-
secticide is applied once to peanuts.
Harvesting dates vary among the four crops and wide yield
fluctuations are present. In the case of beans, most of the farmers
harvest by "convite." Under this system, the owner of the farm
prepares a large meal for the men, women and children working
in the harvest and no cash payment is involved. The people are
willing to provide their labor because they receive the same help
when they harvest their own crops. This is a system of mutual ex-
change of labor for mutual help among the farmers and is carried
out in a festive mood. The "convite" is also practiced in other
systems where beans are involved; i.e., beans as sole crop and
crop mixtures on rainfed land. Perhaps one contributing factor is
the more complex harvesting and packaging process involved in
bean harvesting. After being pulled by hand, the dry plants are
collected over a canvas and mules are passed over them to thresh
out the grains. Then the grains are cleaned and sacked.
Marketing for beans and maize is through middlemen at the
farm gate on these lowland farms where access to roads is more
general. Rice is sold to local millers. All peanut production is
bought by "La Manicera," which is the only peanut processing
plant in the country. This company finances all peanut produc-
tion and deducts that money at harvest time. Farmers feel that
peanut production is not profitable but they plant this crop as a
means of obtaining cash from the loan to subsist during the
period when they do not have another feasible choice.

TABLE 6. Characteristics of short-cycle sole crops systems on irrigated land in Las Cuevas watershed, Dominican Republic, 1982.

Land Preparation Planting Fertilization
Rate Rate

Weeding Harvestin

Crop Rotation Time Means Time Means (kg ha-1) Time Type (kg ha-1) Time Means Pesticides Time (kg ha-1) Marketing

Rice (R) B P Feb.- Oxen Apr.- Hand 73 May(l) Urea 145-363 May- Hand None Aug- 1450-3630 Local millers
with May June(1) Jun.(machete) Sep.
March Flow

Bran (B) R B March Oxen Apr. Seed 73-87 May Urea 73-254 May Hand 1 applic. Jul) 72L-1452 Middlemen
Aug. with Sep. drill Oct. or Oct.(machete) of insect. Dec. at farm gate
Dec. plow Jan. with Feb. 15-15-15 Feb. mixed with March
mule liquid

Peanut(P) R B M March Oxen Apr. Seed 73 None May Hand 1 applic. July 544-1452 Processing
Aug. with Sep. drill Oct.(machete) of powdered Nov plant
plow with insect.

Maize (M) B P March Oxen
Aug. with

Apr. Seed
Sep. drill

May Hand None


Aug. 363-2250

at farm gate




Short-cycle Sole Crop Systems on Rainfed Land

Table 7 shows that bean, maize, pigeon pea and peanut are the
main short-cycle sole crop systems grown on rainfed land. With
the exception of pigeon peas, which is grown only once a year,
crops can be planted twice each year. Land preparation starts in
March for all crops; the second time for bean, maize and peanut
is in August. It is performed by hand with a machete in the case
of pigeon pea, while an oxen with plow or a machete are used for
the other crops.

Planting occurs within a month after the land has been
prepared. All crops are planted by hand with a machete although
in some cases peanut planting is done with a seed drill and a
mule. Seed rates for bean, maize, pigeon pea and peanut are 73,
43, 14, and 80 kg ha 1, respectively. Some of the farmers who
harvest beans in July-August provide bean seed to those who
plant in September with the agreement that when these farmers
finish their harvest in December, they will return an extra 50% of.
the seed borrowed. Under this system, the farmers harvesting in
July and August conserve the germination quality of the seed and
obtain a 50% bonus. The farmers planting in September need no
cash for seed purchases. *

The use of fertilizers and pesticides is not common. Weeding is
done during the same time of the year for all crops and is per-
formed with a machete. Yields are lower than those obtained on
irrigated land owing in part to the occurrence of periodic
Marketing under these systems, in which are produced on the
more accessible rainfed lands, is very similar to that for irrigated
systems. Peanut production is sold to "La Manicera" under the
same contract discussed above. The other three crops are sold to
middlemen who come with their trucks to purchase the output at
the farm gate or nearest road. Sometimes, pigeon peas are
transported by mules to be sold in the nearest market.

Short-cycle Crop Mixture Systems on Rainfed Land
Bean-maize, bean-pigeon pea, and bean-pigeon pea-maize
(Table 8) are the three most important crop mixtures found on
rainfed land. They are grown only once a year with the exception
of bean-maize which is produced twice each year. The bean-
pigeon pea-maize crop mixture is mostly found on more remote
farms in the uplands. Farmers argue that under this system, if
one crop fails it is still possible to obtain some production from
the others; that is, this system guarantees them the possibility of
a certain amount of food for their families.

TABLE 7. Characteristics of short-cycle crops systems on rainfed land in Las Cuevas 1 watershed, Dominican Republic, 1982.

Land preparation
Crop Rotation Time Means

Time Means (kg ha)

Fertilization Harvesting
and Weeding Yield 1
Pesticide Time Means Time (kg ha ) Marketing

Bean March Oxen w/plow or April Hand 73 Rarely May Hand July 167-725 Middlemen
Aug. hand (machete) Sept. (machete) used Oct. (machete) Dec. at farm gate

Maize March Oxen w/plow or April Hand 43 Rarely May-June Hand Aug.- 363-1183 Middlemen
Aug. hand (machete) Sep. (machete) used Oct-Nov.(machete) Sept. at farm gate

Pigeon pea March Hand April Hand 14 None May-June Hand Jan. 363-1088 Middlemenat
(machete) (machete) (machete) (for 2-3 farm gate or
months) in mules to
nearest market

March Oxen w/plow or April Seed drill 80
Aug. hand (machete) Sep. w/mule or
hand (machete)

None May Hand July 239-624
Oct .(machete) Dec.

TABLE 8. Characteristics of short-cycle crop mixture systems on rainfed land in Lasi Cuevas watershed, Dominican Republic, 1982.

Land Preparation

Crop mixture Rotation Time Means

Planting Fertilization We. Harvesting
Rate I and eednYield
Time Means (kg ha ) Pesticide Time Means Time (kg ha- ) Marketing

Bean-maze March Oxen w/plow or April Hand Bean: None May Hand Bean: 181-725 Middlemen
eahand (machete) (machete) 50-73 (machete) July at farm gate
P.Pea: P. Pea: 145-617
7-15 Nov.-Feb.

March Oxen w/plow or March Hand Bean: None April Hand Bean: 290-653 Middlemen
Bean-maize Aug. hand (machete) Sep. (machete) 50-73 Oct. (machete) July; at farm gate
Maize: Nov-Dec.
15-22 Maize: 218-580

March Oxen w/plow or
hand (machete)

April Hand Bean:
(machete) 43-65

None Continu- Hand Bean: 109-377 Home
ously (machete) Julyconsum
P.Pea: 240-435 conuptIn
Maize: 196-363




Bean-pigeon pea-


Land preparation takes place in March for all crops. A second
crop of bean-maize requires land preparation in August. For all
systems, the land is prepared with oxen and plow or with a
Planting is done with a machete, opening a small hole in the
soil and dropping in the seed. Seeding rates are similar in all
systems except that less bean seed is used in the bean-pigeon pea-
maize association.
Fertilizers and pesticides are not used in these systems.
Weeding is done by hand with a machete and, in the case of
bean-pigeon pea-maize, is a continuous activity carried out by all
members of the family.
Yields vary among the three crop mixtures and from those ob-
tained on sole crop systems. Output of bean-maize and bean-
pigeon pea is sold to middlemen. The production from the bean-
pigeon pea-maize crop mixture is consumed at home.

This paper has described the small farming systems in Las
Cuevas watershed of the Dominican Republic. Several important
characteristics, some of them unique in this area, were found.
The role of crop associations in these farming systems was a
relevant finding. For example, 82% of the maize and 90% of the
pigeon peas are grown in association with other crops. Further-
more, all output from the bean-pigeon pea-maize association is
devoted to home consumption.
Two systems of mutual help among the farmers were also
found. One consists of the exchange of bean seed between those
harvesting in July-August and those planting in September.
The former conserve the germination quality of the seed and ob-

tain a 50% bonus, while the latter do not need cash for seed pur-
chases. The "convite" system is the means by which farmers
harvest their bean crops without incurring labor expenses.
Farmers are willing to provide their labor because they receive the
same help when they harvest their own crops.
Peanut production, although not profitable, is carried out as a
means of obtaining cash from a loan to subsist during the period
when they do not have another feasible choice.
Although a relatively small amount of all the land in the water-
shed is devoted to short-cycle crops, these systems produce high
rates of soil erosion that are unacceptable. Increasing population
pressures are likely to worsen this problem. The importance of
these systems to the farmers' diets preclude any policy that would
prohibit their future production. Perhaps the problem could be
alleviated by the development of improved technology that
would bring about increased production in the uplands on a
smaller land area.

1. Antonini, G., K. Ewel, R. Fisher, J. Sartain, P. Hildebrand, T. McCoy, H.
Safa and I. Russo. 1981. Integrated training and research program in natural
resources management for the Dominican Republic with special applications for Las
Cuevas watershed. Gainesville, FL: University of Florida Press.
2. Hildebrand, P.E. 1981. Combining disciplines in rapid appraisal: the
sondeo approach. Agr. Adm. 8:423-432.
3. Mendenhall, W., L. Ott and R. Scheaffer. 1971. Elementary survey sampl-
ing. Second Ed. North Scituate, MA: Dusbury Press.
4. Ruthenberg, H. 1980. Farming systems in the tropics. Oxford, New York:
Oxford University Press.



Predators and Parasites of Insect Pests on

Cantaloupe and Asparagus Bean,

St. Croix, U.S. Virgin Islands

R. G. Bland
Biology Department
Central Michigan University
Mt. Pleasant, MI 48859

Cantaloupe (Cucumis melo L.) and asparagus beans (Vigna
unguiculata subsp. sesquipedalis [L.] Verdc.), were sampled
weekly for insect pests and their predators and parasites during
the spring dry season. The three major pests of cantaloupe
were melonworms (Diaphania hyalinata L.), melon aphids
(Aphis gossypii Glover), and powdery mildew (Erysiphe sp.).
Fire ants(Solenopsis geminata F.) became serious secondary
pests by tending aphids. All four pests required chemical con-
trol. Syrphid, chrysopid, and coccinellid larvae preyed on

W. I. Knausenberger
College of the Virgin Islands
Agricultural Experiment Station
P.O. Box 920, Kingshill
St. Croix, U.S. Virgin Islands 00850

aphids but these predator populations were very low and
developed too slowly to exert significant control. Two
ichneumonid, one chalcid, and one tachinid species were
reared from melonworm pupae and one of the ichneumonids,
Agrypon caribbaeum Bland, occurred in sufficient frequency
to consider its use as a biological control agent.
Keywords: Aphis craccivora, Aphis gossypii, asparagus beans,
cantaloupe, cowpea aphid, Diaphania hyalinata, Liriomyza
sativae, melon aphid, melonworm, parasites, predators.

Cowpea aphids (Aphis craccivora Koch) were the major pests
on asparagus beans, but fair to good control was achieved on
most plants from natural population increases of syrphid,
chrysopid, and coccinellid larvae, and wasp parasites. Fire ants,
leafhoppers (Empoasca sp.), and vegetable leafminers (Liriomyza
sativae Blanchard), were secondary pests.
Only 6% of the fruit and vegetables consumed in the U.S.
Virgin Islands are grown locally (Mullins and Bohall, 1974).
These. crops are produced in gardens for home use or in small
commercial plots and sold at roadside stands or small, local
grocery stores. The College of the Virgin Islands Agricultural Ex-
periment Station and Cooperative Extension Service and the
Virgin Islands Department of Agriculture continuously en-
courage island residents to establish more and improved home
gardens and small farms to decrease dependence on imported
food, provide local income, and reduce food costs.
St. Croix has more level and open terrain than the other two
U.S. Virgin Islands and historically had been the center of the
sugarcane industry. Eighty percent of this island is classified as
subtropical, dry forest zone (Ewel and Whitmore, 1973). The re-
maining 20% is a region of steep slopes in the northwest corner
and is classified as a subtropical, moist forest zone. The dry forest
zone is the major agricultural region. The average maximum and
minimum temperatures are 30 annd 23C, ad the average an-
nual rainfall near the experiment station is ca. 110 cm. However,
irregular rainfall and high evapotranspiration typically cause a
moisture deficit January through April so that crops are subject to
periodic drought since ground and surface waters are not readily
available for irrigation.
Cantaloupe, Cucumis melo L., is a nutritious and popular food
on St. Croix. The vines are able to tolerate fairly low moisture
conditions although disease can be a major problem during the
wet season. Different varieties of this crop have been tested for
productivity at the St. Croix experiment station.
Vigna unguiculata subsp. sesquipedalis (L.) Verdc., a subspecies
of black-eyed peas (cowpeas or southern peas), is known as
asparagus bean, Bodie bean, snake bean or yard-long bean. The


plant is grown in Southeast Asia and some areas of Africa and the
West Indies (excluding the U.S. Virgin Islands) primarily for its
immature pods which may attain a length of 1 m under optimum
growing conditions (Purseglove, 1968). Asparagus beans are a
climbing or bush-type annual, day-neutral, and tolerate heat and
relatively dry conditions better than Phaseolu vulgaris L., the
common bean. However, asparagus beans require a higher rain-
fall than the drought-tolerant, common black-eyed peas
(Purseglove, 1968).
This research was conducted at the College of the Virgin
Islands Agricultural Experiment Station (CVIAES), St. Croix.
The objectives were to obtain data on insect pest, predator, and
parasite populations on experimental plantings of cantaloupe
and asparagus beans as the crops developed during the spring dry

The Experiment Station soil is a Fredensborg clay loam, a
highly calcareous, friable soil with a pH of 8 and 1.5 to 2.0%
organic matter. It is very low in nitrogen, sulfur, and iron, and
moderately low in phosphorous, copper, and manganese.
Cantaloupe v. 'Top Mark,' was seeded January 18, 1982, in
shallow lm2 depressions 2 m apart in 20 m rows. The six rows
were spaced 2 m apart. Young plants were thinned to two per
depression. Insect and other arthropod populations were
monitored weekly on the entire plant surface and specimens were
collected by hand for preservation or parasite rearing.
Asparagus beans (Yates Co., New Zealand) were planted
January 18, 1982, in shallow 0.1 m2 depressions spaced 0.6 m
apart in rows with 1 m centers. Rows were kept weed-free and the
climbing vines were tied to poles. All insects on a plant sample
were counted weekly. A plant sample consisted of one trifoliate
leaf (including the petiole) near the bottom, middle and top of a
plant, and the length of the main stem. The first true leaf of a
newly emerged seedling substituted for a trifoliate. During the
first four weeks after seedling emergence 96 plants were sampled
weekly and thereafter 24 plants formed a plant sample, the
reduction in number due to the increased plant size.


Nearly 7.5 cm of rain fell during the 10-week study. The
average daily temperature was 29*C.

Only 69% of the seeds germinated, and during the following
two weeks 12% died from damping-off (Rhizoctonia suspected).
Powdery mildrew (Erysiphe sp.) developed into a severe problem
by the time the first fruit was approximately 8 cm in diameter.
The mildew first appeared 17-18 days after seedling emergence
and was observed on the underside of most leaves one week later.
One or more fungicide sprays are needed when the first symp-
toms appear, otherwise the basal leaves die and leaf death slowly
progresses distally on the vine until only the distal third or less of
a plant remains green 12 weeks after seedling emergence.

Melonwornis (Pyralidae)
Eggs of the melonworm, Diaphania hyalinata (L.), first ap-
peared three and a half weeks after seedling emergence and 22%
of the leaves had one or more eggs on them at this time. One
week later 36% of the plants had larvae, 31% of the leaves had
feeding damage and 12% of the leaf surface was eaten (Fig. 1).
By the fifth week after emergence 63% of the plants had melon-
worms, and an average of 3.2 larvae occurred per plant. Larvae
were on 89% of the plants by the sixth week and thereafter all
plants were infested.

FIG. 1. Melonworm larvae on cantaloupe.

3 4 5 6 7 8
Weeks After Seedling Emergence

By the sixth week the ovipositional rate of the increasing adult
population caused moderate-size plants (35-40 leaves/plant) with
3-5 melonworms to develop economically threatening popula-
tions two weeks later with 43-74 larvae and 20% of the total leaf
surface eaten (leaf number ranged from 83-136/plant). If no in-
secticides were used at this point the plants would be heavily or
completely skeletonized in about three more weeks.
Only 73% of the field-collected pupae were viable and 49% of
these were parasitized. Seventy percent of the parasitism resulted
from a new species of ichneumon wasp, Agrypon caribbaeum-
Bland. Rearing of this larval parasite for potential biological con-
trol of melonworms is being conducted by the USDA-ARS
Southern Region U.S. Vegetable Laboratory, Charleston, South
Carolina (personal communication, Kent D. Elsey). A. carib-
baeum is described by Bland (1984).


A second ichneumon, Eiphosoma dentator (F.), accounted for
only 3% of the emerged parasites. It ranges from southern U.S.
and the West Indies to South America and is common in the
tropics (Krombein et al., 1979). Most of its hosts are in the
Pyralidae, subfamily Pyraustinae, but it had not been recorded as
a melonworm parasite.
Nearly 15% of the parasites were a chalcid wasp, Brachymeria
ovata Say, a known pupal parasite of melonworms. It occurs
throughout most of the U.S. and Mexico and has been recorded
.from the West Indies (Thompson, 1955; Krombein et al., 1979).
A tachinid fly, Nemorilla pyste Walker formed 12% of the
parasite complex. It is found in most of North America including
Mexico and has been recorded as a melonworm parasite (Arnaud,

Leafminer Flies (Agromyzidae)
The vegetable leafminer, Liriomyza sativae Blanchard, first ap-
peared in cotyledons four days after seedling emergence and, by
the following week when the leaves were open, nearly 50% of the
cotyledon surface was mined. The third week after emergence
when up to three pairs of leaves were open, most of the mines
were on the first pair of leaves and averaged 0.5 mines per leaf.
New miner damage decreased by the fourth week and damage
appeared negligible thereafter.

Aphids (Aphididae)
Melon aphids, Aphis gossypii Glover, first appeared on the
ventral leaf surfaces ten days after seedling emergence and the
population increased rapidly thereafter. The population was
localized on a few vines at first but spread to all plants by the
sixth week. No aphid-infested young plants (6-20 leaves) survived
to bear fruit unless they were sprayed with an insecticide. Leaves
of young plants with high aphid populations (ca. 40 aphids/16
cm2 leaf surface) curled downward and the plants became
stunted. Aphid control is needed before leaf curling begins.
Older plants (with more than 85 leaves) with moderate to high
infestation grew poorly. Complete spray coverage of a leafs ven-
tral surface is important for effective control, but this can be dif-
ficult to accomplish due to the horizontal position of leaves and
their proximity to the ground.
Aphidophagous syrphid larvae, Pseudodoros clavatus F., first
appeared four weeks after seedling emergence (two weeks after
aphids were first recorded). However, the syrphid population in-
creased at a slow rate and occasional clusters of 3-5 larvae/leaf
were not observed until nearly ten weeks had passed and signifi-
cant aphid damage had occurred. Even at this time the syrphid
population was too low (1 larva/42 leaves) to exert sufficient con-
trol of the high aphid population.
Lacewing larvae, Chrysopa sp., were occasionally observed after
the ninth week, but their population never exceeded 1 larva/85
leaves. Lady beetle larvae, Cycloneda sanguinea Casey, were less
common and averaged 1 larva/428 leaves.

Ants (Formicidae)
Workers of the fire ant, Solenopsis geminata F., were first
observed on plants four days after seedling emergence and the
ant population increased parallel with the aphid population.
Plants with the highest aphid populations generally had large
numbers of ants tending the aphids. It was not uncommon to
find a leaf with 400 aphids and 75 ants. Occasionally ants were
observed transporting aphids. On young plants (6-20 leaves) ants
frequently covered part to nearly all of the basal leaves with soil
while they tended the aphids. Ant control would probably reduce
aphid dispersal and increase their susceptibility to parasites.


Coreid Bugs (Coreidae)
Two specimens of Anasa scorbutica F. were recorded. This
species has been reported as an occasional pest of melons in Puer-
to Rico (Wolcott, 1948).

Asparagus Beans
Damping-off (R. solani suspected) killed 5% of the seedlings.
Nearly 50% of the deaths occurred during the first four days after
emergence; the disease ceased 19 days after emergence. Powdery
mildew (Erysiphe sp.) occurred on the basal third of ca. 75% of
the plants 45 days after emergence. It was visible on most leaves
by the last harvest date (70 days after emergence) and ca. 50% of
the leaves had fallen by this time. It was difficult to determine if
fungicide applications would have been cost-effective because
leaf-drop from water stress and early senescence are complicating
factors. Asparagus beans are reported to be disease-susceptible
although less so than common beans (Martin and Ruberte, 1980).

Aphids (Aphididae)
The cowpea aphid, Aphis craccivora Koch, first appeared four
days after seedling emergence and reached a peak population of
155 individuals per plant sample approximately one week prior to
the first harvest (Table 1). One week later the population had
decreased by over 90% to 8.5 aphids per sample, followed by a
slight increase during the remainder of the harvest period.
Aphids were concentrated on the main and lateral stems, the
underside of the leaves near the petiole and, toward the end of
the harvest period, on the basal half of nearly-mature pods.
Aphid damage varied depending on the age of the bean plant
and the aphid population. Ten days after seedling emergence
when the second pair of trifoliate leaves were expanding, high
populations of 50-150 aphids on the entire plant were recorded
on some seedlings. These plants became stunted and did not
resume growth until the aphid population was nearly eradicated
by predators six weeks later. The plants then grew rapidly and
produced a crop; although the plant size was only about 75%
and the yield less than 50% of the average plant.
Bean plants that developed moderate to high aphid popula-
tions (6-20 aphids per plant sample; plant height was 80-110 cm)
four weeks after emergence were able to tolerate aphid damage
reasonably well for an additional three weeks. Some leaf curling
and growth reduction occurred, but few pods had aphids on
them. After this time, predators greatly reduced the aphid
population on ca. 75% of the plants with high populations.
Parasitized aphids and parasitic wasps were also observed but not
collected. Plants that still had high aphid populations at harvest
also had aphids on the basal half of the pods that were ready for
picking. The pods were slightly curled and generally unacceptable
because of the crushed aphids left on the pod during picking.
Plants with low aphid populations four weeks after emergence
(1-5 individuals per plant sample) grew well and the size and crop
yield were satisfactory (approximately 4400 kg/ha or 4000
lb/acre). The pods were generally aphid-free.

Aphid Predators
P. clavatus larvae (Syrphidae) appeared ten days after plant
emergence and reached a peak population of 38 larvae per plant
sample five weeks later (one week prior to harvest) (Table 1). The
maximum populations of syrphid larvae and aphids were record-
ed on the same sampling date although the aphids had nearly
reached this peak the previous week, whereas syrphid larvae were
less than half their maximum population at that time. One week
later (at harvest) the syrphid population had decreased by 85%
and the aphids by over 90%. No syrphids were recorded during
the remaining two weeks on plant samples although they were
observed on other bean plants in the rows.

Chrysopa sp. larvae (Chrysopidae) with a white, waxy covering
were first recorded 24 days after seedling emergence. The popula-
tion increased to 25 larvae per plant sample two weeks later and
peaked at 65 larvae per plant sample the following week which
was the same date as the maximum aphid population (one week
before harvest) (Table 1). By the next week the lacewing popula-
tion had declined 81% ,along with an even greater reduction in
the aphid population. Adult lacewings were not commonly
C. sanguinea adults (Coccinellidae) were first recorded 24 days
after seedling emergence. They reached a maximum number of
nine per plant sample three weeks later when/the aphid popula-
tion peaked, and rapidly decreased thereafter (Table 1). Unlike
lacewing adults, lady beetle adults were much in evidence. Larvae
were not recorded until nearly seven weeks after seedling
emergence and their population peaked two weeks later, during
the middle of harvest, at seven larvae per plant sample. Lady bee-
tle larvae continued the predation pressure as the impact of the
syrphid and lacewing larvae declined during the last three weeks
of harvest.

Ants (Formicidae)
S. geminata were tending cowpea aphids and the ant popula-
tions increased parallel to the aphid populations. The ant
number peaked at 6.3 individuals per plant sample during the
same two weeks of maximum aphid populations (Table 2) and
declined rapidly thereafter. Small ant nests were common at the
base of bean seedlings with the highest aphid and ant numbers,
but gradually declined as the plants matured so that few nests
were still present by the time harvest occurred. Ants did not cause
any direct damage to bean plants although nests at the base of
seedlings may have increased soil dessication.

TABLE 1. Population development of aphids and aphid predators on asparagus

Mean No. Specimens per Plant Samplea
Aphis Pseudodoros Chrysopa Cycloneda sanguine
craccivora clavatus sp. adults larvae
Date larvae larvae
1/28b 2.5
2/4 4.6 1
2/11 23.3 2
2/18 40.6 12 1 2
2/25 43.8 13 2 2
3/5 151.3 16 25 4
3/11 155.2 38 65 9 1
3/19c 8.5 5 12 0 6
3/25 18.3 4 1 7
4/11 16.4 7 6

aA plant sample consisted of 1 trifoliate (including petiole) near the
bottom, middle and top of plant, and the length of the main stem. The
first true leaf substituted for a trifoliate on newly emerged plants.
N=96 for weeks 1-4 and n=24 thereafter.
bSeedlingsemerged Jan. 24-25, 1982.
CFirst harvest was March 22, 1982.



Leafhoppers (Cicadellidae)
A population of pale green leafhoppers (Empoasca sp.)
developed parallel to the aphid and ant populations, reaching a
peak of two per plant sample nearly two weeks prior to the first
harvest and then rapidly declining (Table 2). Most of the popula-
tion was concentrated below 45 cm on the plant and single
leaflets in this height range averaged two individuals each.
Damage symptoms occurred as weak chlorotic areas on some
leaves, but otherwise the damage from leafhoppers appeared

Leafminer Flies (Agromyzidae)
L. sativae first appeared four days after seedling emergence and
produced an average of 2.5 mines per leaflet (range, 1-17) one
week later (Table 2). At that time and during the following week
approximately 16% (range, 1-50%) of the leaf surface was
damaged. As plant growth progressed over the next three weeks,
these percentages declined and then began to slowly increase to
infestation levels similar to the second and third week of growth.
Leaf damage was confined to the basal /4 of the plant during the
last 2/3 of the growth period. By the time the harvest was com-
pleted, mines had also appeared in the middle and terminal
leaves apparently due to an increase in population from a new
generation. Immediate destruction of the plants should help
limit this new population.
The effect of leafminers on plant growth was difficult to
estimate because leaves with mines did not turn brown or drop
off. During the ten weeks between emergence and last harvest,
18% of the leaves were infested and about 7% of their surface
was mined by larvae. However, between the third and eighth
week the percentage of leaves mined was low because of the rapid
production of new leaves and an apparent plateau in the leaf-
miner population growth. In general, the impact on plant growth
appeared to be minimal. Johnson et al. (1983) noted that

TABLE 2. Population development of secondary insect pests on asparagus beans.

Mean No. per Plant Samplea
Solenopsis Empoasca sp. Liriomyza sativae
geminata e of leaf f mines/leaflet
Date w/damage
1/28b 0.6 0.04 (1 0.02
2/4 1.9 0.08 16 2.5
2/11 1.8 0.6 15 1.1
2/18 2.4 1.0 3 1.0
2/25 4.3 1.3 1.5 0.3
3/5 6.3 1.2 2 0.3
3/11 5.6 2.0 3 0.7
3/19c 0.7 0.5 7 1.5
3/25 0.8 0.5 12 1.6
4/11 0.6 0.4 10 2.0

A plant sample consisted of 1 trifoliate (including petiole) near the
bottom, middle and top of plant, and the length of the main stem. The
first true leaf substituted for a trifoliate on newly emerged plants.
N=96 for weeksl-4 and n=24 thereafter.
Seedlings emerged Jan. 24-25, 1982.

SFirst harvest was March 22, 1982.


although L. sativae mining in tomato leaves could greatly reduce
the photosynthesis rate, it may not reduce the rate to a level that
decreases fruit production.
WaspS in the family Braconidae (Opius sp.) and Eulophidae
(Diaulinopsis sp. and Chrysonotomyia sp.) were observed
parasitizing leafminer larvae in the field and adult wasps were
reared from leafminer pupae. In one instance 42 adult leafminers
and 20 wasps emerged from one group of leaves.

Miscellaneous insects and mites
Table 3 lists all insects and mites recorded on asparagus beans.
Those not previously discussed were observed sporadically.

TABLE 3. Arthropods collected from asparagus beans.

Plant feeders
Thripidae Thrips
Pentatomidae Stink bugs
Nezara viridula (L.) Southern green stink bug
Thyanta sp.
Delphacidae Planthoppers
Sogata sp.
Cicadellidae Leafhoppers
Empoasca sp.1
Agallia albidula (Uhler)1
Aphididae Aphids
Aphis craccivora Koch Cowpea aphid
Chrysomelidae Leaf beetles
Ceratoma ruficornis Oliver
Noctuidae Noctuid moths
Spodoptera sp. an armyworm
Agromyzidae Leafminers
Liriomyza sativae Blanchard Vegetable leafminer
Tetranychidae Red spider mite
Tetranychus sp.
Miscellaneous feeders
Pselaphidae Shortwinged mold beetle
Formcidae Ants
Solenopsis geminata (F.) Fire ant
Halictidae Halictid bees
Chrysopidae Green lacewings
Chrysopa sp.
Coccinellidae Lady beetles
Cycloneda sanguinea Casey
Syrphidae Flower flies
Pseudodoros clavatus (F.)1
Tachinidae Tachina flies
Braconidae Braconid wasps
Opius sp.
Eulophidae Eulophid wasps
Diau/inopsis sp.1
Chrysonotomyia sp.'

'Not listed in Miskimen and Bond (1970).


Chemical pest control does not always offer the small farmer
engaged in traditional subsistence farming a sufficient increase in
productivity to compensate for the costs of applying insecticides
over a whole field (Brader, 1982). Pesticide usage has primarily
benefited larger farmers with substantial cash crops. Although
subsistence farming is uncommon in the U.S. Virgin Islands,
there are small home gardens and some small cash crop farms.
The CVIAES and Cooperative Extension Service have encouraged
these endeavors and are continuing to apply simplified integrated
pest management principles where possible.
Melonworm control on cantaloupe by the ichneumon A. carib-
baeum may be feasible and its future use will depend on ex-
perimental field releases currently planned. Satisfactory aphid
control on cantaloupe from predators and parasites did not occur
and insecticides were needed when the plants were young or leaf-
curling and death would soon follow on these relatively sensitive
plants. Ant control measures such as bait applications or soil
drench treatment of nests may help to delay aphid population
buildup. This would provide more lead time for natural control
agents to establish high populations.
In contrast to cantaloupe, moderate to good aphid control on
asparagus beans by natural enemies did occur, although there
may be a high degree of risk unless predator populations are
monitored. Asparagus bean seedlings with high initial aphid
populations (50- aphids per entire plant) grew poorly and
mature plants with high populations had inferior quality pods
and aphid masses on the basal portions of the pods. The use of
insecticides for aphid control is warranted in these cases. Plants
with moderate to high aphid populations (6-20 per plant sample)
four to seven weeks after emergence developed severe infestations
as harvest approached but most of the aphids were killed by

predators and parasites over a one- to two-week period. Syrphid
larvae initiated aphid predation followed shortly by lacewing lar-
vae and lady beetle adults. One week before the simultaneous
peaks of these predator populations, the rapidly developing
aphid population reached a plateau apparently because predation
coupled with wasp parasitism were nearly equal to aphid
reproduction. Lady beetle larvae continued the predation
pressure and the aphid population declined dramatically along
with the adult lady beetles and lacewing and syrphid larvae. In
this case it is difficult to determine whether an insecticide should
be used when the aphid infestation becomes severe or whether a
farmer could monitor the natural enemy populations to deter-
mine if they will be effective in controlling the aphids.
Augmentation of the natural enemy population with releases
of predators (especially lacewings and lady beetles) or perhaps
with parasites when the plants have low to moderate aphid
populations may make insecticide application to asparagus beans
unnecessary. The cost to purchase and apply these natural control
agents, if a source were available, would need to be competitive
with insecticide costs. In addition, encouraging non-pest aphid
species that are specific to plants that border the crop fields would
help maintain higher endemic populations of predators and
parasites that may in turn respond more efficiently to aphid in-
festation of a crop. A survey of the aphid species on local weed
and non-weed plants may be useful in determining what host
plants to seed in border areas or as intercrops. The development
and dissemination of simple, practical methods such as these for
the small farmer are needed. In a recent review, Matteson et al.
(1984) deal with the problems of pest management in small farm-
ing systems and conclude that traditional cropping practices often
supply a basis for improved pest control that can be adapted to
the existing socioeconomic conditions.

The following research entomologists of the Systematic Entomology Laboratory,
U.S.D.A., identified specimens for this study: J.P. Kramer (Cicadellidae), M.B.
Stoetzel (Aphididae), P.M. Marsh (Braconidae), E. Grissell (Chalcididae), M.E.
Schauff (Eulophidae), D.R. Smith (Formicidae), F.C. Thompson (Syrphidae), and
D. Wilder (Tachinidae). H. Townes, American Entomological Institute, and C.
Dasch, Muskingum College, identified the ichneumon wasps.

1. Arnaud, P.H. 1978. A host-parasite catalog of North American Tachinidae
(Diptera). USDA Misc. Pub. 1319.
2. Bland, R.G. 1984. Agrypon caribbaeum, a new species of ichneumon wasp
(Hymenoptera: Ichneumonidae) from the U.S. Virgin Islands. Ann. Ent. Soc.
Amer. 77:29-31.
3. Brader, L. 1982. Recent trends of insect control in the tropics. Ent. Exp. &
Appl. 31:111-120.
4. Ewel,J.J., andJ.L. Whitmore. 1973. The ecological life zones of Puerto Rico
and the U.S. Virgin Islands. For. Serv. Res. Paper ITF-18.

5. Johnson, M.W., S.C. Welter, N.C. Toscano, I.P. Ting, J.T. Trumble.
1983. Reduction of tomato leaflet photosynthesis rates on mining activity of
Liriomyza sativae (Diptera: Agromyzidae). J. Econ. Ent. 76:1061-1063.
5. Krombein, K.V., P.D. Hurd, Jr., D.R. Smith, and B.D. Burks. 1979.
Catalog of Hymenoptera in America North of Mexico. Vol. 1-3. Smithsonian In-
stitution Press, Washington, DC.
6. Matteson, P.C., M.A. Altieri, W.C. Gagne. 1984. Modification of small
farmer practices for better pest management. Annu. Rev. Ent. 29:383-402.
7. Martin, F.W., and R.M. RubertE. 1980. Techniques and plants for the
tropical subsistence farm. USDA Agric. Rev. & Man. S-8.
8. Miskimen, G.W., and R.M. Bond. 1970. The insect fauna of St. Croix,
United States Virgin Islands. New York Academy of Sciences Scientific Survey of
Porto Rico and the Virgin Islands. Vol. 13, Part I.
9. Mullins, T., and R.W. Bohall. 1974. Fruits and vegetables: production and
consumption potentials and marketing problems in the U.S. Virgin Islands. V.I.
Agric. Exp. Stn. Rep. No. 2.
10. Purseglove, J. 1968. Tropical Crops. Dicotyledons. Longman, London.
11. Thompson, W.R. 1955. A catalogue of the parasites and predators of insect
pests. Section 2, host parasite catalog. Part 3, hosts of the Hymenoptera (Calliceratid
to Evaniid). Commonwealth Institute of Biological Control, Ottawa, Canada.
12. Wolcott, G.N. 1948. The insects of Puerto Rico.J. Agric. Univ. Puerto Rico



Vagility and Probability of Survival in

Two Weevils (Coleoptera, Curculionidae):

the sugarcane rootstalk borer weevil

(Diaprepes abbreviatus [L.]) and the

sweet potato weevil (Cylas formicaius [F.])

ILonce Bonnefil, Ph.D.
Inter American University of Puerto Rico
243 Viena Street, College Park, Rio Piedras, PR 00921

The sugarcane rootstalk weevil borer Diaprepes abbreiviatus
(L.) moves freely among numerous plant hosts within Puerto-
rican agroecosystems. The sweet potato weevil, on the con-
trary, appears circumscribed to the family Convolvulaceae.
The fecundity, life cycle and longevity of the two insects were
probed to unveil the biological nature of vagility. Diaprepes
fecundity was greatly enhanced by the shift from wild to

cultivated hosts, development was not influenced appreciably,
and longevity was greater in the sedentary species. It is assum-
ed that vagile populations are briefly boosted by host shifts
even ending in expansion thrusts though longevity is not
necessarily extended. Under sedentary conditions populations
are generally low but stable.

Historical Recount of Diaprepes and Cylas
as Agricultural Pests
Beavers et al. (1978) have compiled an extensive bibliography
of the sugarcane rootstalk weevil borer Diaprepes abbreviatus
which spanned the period from 1903 to 1978. For about 30 years
there was a near-loss of interest in the insect pest. Interestingly
enough, this lapse coincides with the period between the release
of the organochlorine insecticides for use by the public and their
ultimate banning. These pesticides when applied to the soil af-
forded a perfect control of Diaprepes which thus became inconse-
Around 1979, however, the absence of the chemicals started to
be felt through a recrudescense of the weevil borer. A survey by
the U.S. Department of Agriculture revealed that 82,000 of the
115,000 acres of sugarcane in Puerto Rico were infested by the in-
sect. The annual production of 1,000,000 metric tons/year was
reduced to an estimated 150,000 metric tons/year, representing a
loss of $73 million (Beavers et al., 1978).
Diaprepes was accidentally introduced into the United States
presumably in 1964 and the infestation has risen steadily since
(Woodruff, 1964; Selhime and Beavers, 1972). The weevil is now
a serious problem in Florida where it inflicts considerable losses to
the ornamental plants industry of between $140 and $150
million/year. Emergency Federal regulations took effect in Puerto
Rico, making it compulsory that all exports of ornamental plants
to the United States be certified by the U.S. Department of
Agriculture. According to T. Dorney of the SanJuan Star (1970),
30 of the 47 growers of ornamentals were quarantined and could
not export their products. The $10 million-a-year business seem-
ed to be in serious jeopardy with 63% of the producers unable to
ship to the mainland plants, plant parts and cut flowers. It could
have been said that the law was too restrictive, but hundreds of
millions of dollars worth of sugarcane products, citrus plants and
fruits, vegetables and ornamentals, were at stake in Florida and it
was imperative to prevent the spread of the pest to other states of
northern United States.


An evaluation of the damage of the sweet potato weevil in
Puerto Rico could not be found. Generally Cylasformicarius in-
fests the vines, tubers and roots of sweet potato and is found occa-
sionally on morning glory (Ipomea learii (Pexton,) bay hops
(Ipomea pescapreae [L.]). In commercial plantings many tubers
were found to be tunnelled, even totally honey-combed, offering
a repulsive appearance, foul odor and bitter taste. But in Puerto
Rico, sweet potato is not of great economic importance and the
losses caused by Cylas may not be considered significant except
for such academic aspects as the one discussed hereafter.

Description of the Insect Pests
The so-called sugarcane rootstalk borer weevil Diaprepes ab-
breviatus (L.) is a fairly large otiorhynchid beetle (Coleoptera,
Curculionidae). It has a stout abdomen, a trapezoidal thorax one
quarter longer than wide, a narrow head with small arched com-
pound eyes and clubbed antennae distinctly elbowed. The body
is black but colored scales impart to the insect a whole variety of
hues. Individuals collected or reared on different hosts did show
some consistency in coloration but not enough to separate diet
groups. Adult size was equally variable in both sexes, ranging
from 0.85cm to 1.90cm.
The genus Diaprepes is apparently indigenous to the Carib-
bean area with species occurring in Central America and most of
the West Indies. It does not appear to extend into South America
or the United States (Fennah, 1942). Abbreviatus appears to be
the main species occurring in Puerto Rico, Haiti and the Lesser
Antilles with a series of other species occurring on other islands.

The Life Cycles of the Two Weevils
In its development, Diaprepes goes through a complete
metamorphosis. The oval elongate eggs are laid in clusters of
about 30 between leaves tightly held together by a sticky,
transparent, elastic film. The total number of eggs produced by
one female during her life is about 5,000 (Wolcott, 1936 and
1948). The incubation is fairly uniform, lasting an average of


seven days. Upon hatching, the minute larvae cross the leaf sur-
face with a "galloping" motion and reaching the edge, drop to
the ground. On the soil surface they may wander for a while and
finally penetrate the soil in search of tender rootlets on which to
feed. These larvae are small, legless and white, with a distinct
head pattern of yellow and gray. The color of the head, however,
is generally not as deep as that of other larvae found in the soil
along with Diaprepes.
The sweet potato weevil is also an otiorhynchid beetle, but
considerably smaller than Diaprepes. It is shiny looking,
somewhat like a large ant (hence its specific name). Its elongate
snout and head are blue-black as well as the rounded elytra. The
thorax and legs are reddish brown (hence the sub-specific name
of elegantulus).
The reproductive cycle of Cylas is probably not well understood
because of the cryptic behavior of the insect. The larval and pupal
phases develop within vegetable tissues and cannot be observed.
It is not known just where fertilization occurs in nature, though it
is assumed that it occurs mostly in the open. Promptly after fer-
tilzation the female starts burrowing into the plant leaves, stem
and junction point of developing tubers. A study of egg distribu-
tion within whole plants from a highly infested field revealed
that the eggs are distributed in an ascending order, precisely in
the sequence indicated above (Bonnefil, 1983, unpublished
The minute, white, kidney-shaped eggs are laid at the bottom
of shallow depressions carved by the ovipositing female in the
aerial parts or directly at the offshoot, of young tubers. It is possi-
ble that they are laid within the tunnels inside mature tubers. It
is known that the eggs hatch in about seven days, that the larval
instars sum up about three weeks, and the pupal stage another
week inside the tuber.
One generation of the weevil lasts one month in the field or in
storage. It is suspected that the adult may live up to eight mon-
ths. It is also known to fly up to one mile in search of food. Flight
is not an important mode of dissemination, which is done mostly
through the planting of infested cuttings. It has been shown that
adults freed by cutting open a tuber or some other part of the
sweet potato plant showed no dispersive urge, but lingered
around or, at most, moved to the nearest planting. No reference
was found in the literature as to the fecundity of the sweet potato
weevil on sweet potato or any alternate host plant.

To investigate the fundamental nature of vagility, the two
weevils were to be sampled according to selected biological
criteria on their apparently preferred and two incidental hosts, as
shown in the following scheme:
1. Biological criteria (fecundity, oviposition, incubation, hat-
ching success), related to Diaprepes abbreviatus (L.) reared
and maintained on:
a. Orange (Citrus sinensis [Osbeck]), Gereniales, Rutaceae
b. Pigeon pea (Cazanus indicus [Spreng.]), Rosales,
c. Papaya (Carica papaya [L.]), Violales, Caricaceae
d. Mother-of-cocoa (Gliricidia sepium [Jacq.]) Steud Rosales,
2. Biological criteria (fecundity, oviposition, incubation, hat-
ching success), related to Cylas formicarius (F.) reared and
maintained on:
a. Sweet potato (Ipomea batatas [Lam.]), Polemiales, Con-
b. Morning glory (Ipomea learii [Paxton]), Polemiales, Con-
c. Bay hops (Ipomea pescapreae [L.] [Sweet]), Polemiales,

3. Comparisons using the biological criteria results for Diaprepes
abbreviatus (L.):
a. Favorite host (citrus) vs. incidental host (pigeon pea)
b. Wild host (mother-of-cocoa) vs. cultivated host (citrus).
4. Comparison between the vagile and the sedentary weevils or
the consequences of vagility.
A study of the preceding scheme showed that the vagile weevil
was found on plants belonging to widely spaced orders, while the
sedentary weevil was found on plants of the same order and fami-
In all cases, the plant hosts were arbusts or, at most, small
trees, easily found in the vicinity of the university campus. To
assure an ample supply of fresh plant material, arrangements
were made to grow the plants in neighboring yards.
Diaprepes adults were collected at two experimental stations of
the University of Puerto Rico where the insects had been reported
in good numbers on a variety of hosts. They were transported in
plastic containers with screen covers and fed the leaves of the
plants on which they had been captured. The adults of Cylas were
carefully extirpated from the stolons or tubers of the selected
The plastic containers were kept cool and upon arrival at the
university were introduced in a constant-conditions chamber in
which temperature was maintained at 75"F (23.8"C) and light
programmed at 12 hours of light and 12 of darkness. The adults
of Cylas, by copulating pairs, were introduced into plastic snap-
boxes covered with adhesive black plastic to simulate darkness.
On the lower side of the snapboxes 6mm dia holes were drilled
through which 7cm-long sections of stolons would be placed,
wrapped in cotton to avoid damage. The free ends of the sections
were placed in florists' waterpicks filled with 1% sucrose solution.
Probes for the two weevils were made simultaneously, and all
fresh plant material was renewed every three to four days. As
changes were made, observations were recorded.
The main objectives of the research project were largely ful-
filled. Unforeseen difficulties could be overcome, thus a sizable
amount of original data could be gathered. An aspect was added
to the original layout which provided valuable information as to
the annual cycle of infestation of the sugarcane weevil borer. It
had been hypothesized that wild hosts carried over the infestation
from one crop year to the next (more in the case of the vagile in-
sect), residual populations surviving on the wild hosts scattered
among the cultivated blocks.
The pattern turned out to be exactly that. In the case of
Diaprepes, mother-of-cocoa was used as a typical wild host and
morning glory in the case of Cylas. Eggs are laid by both insects in
the known manners, the larvae drop to the ground and penetrate
the soil, taking advantage of the spring rains (April, May) which
loosen the soil surface and impart humidity. The sweet potato
weevil is carried with the infested cuttings and, as the plants start
to grow, first infest the stolons and later the starting tubers.
The criteria of comparison for fecundity, development and
longevity were chosen as follows:
1. Total numbers of eggs laid throughout the residence of the in-
sects in laboratory;
2. Duration of oviposition;
3. Daily rate of oviposition;
4. Average duration of oviposition;
5. Percent live larval births; and
6. Total days lived in the laboratory.
Although computer service was available for the statistical
analysis of the data, it was decided to proceed the traditional way
for the benefit of readers interested in statistical methodology.
The method followed was that of unpaired observations of un-
equal variances. The hypothesis of equal variances was tried and
then given up.



A "t'" was calculated according to a formula by Cochran and
Cox (1957). The prime indicates that the criterion is not
distributed as the Student's "t."
The few data obtained from the sweet potato weevil are related
to the total of eggs laid in the laboratory, the duration of oviposi-
tion and the total of days lived in the laboratory.

1. The total number of eggs laid by Diaprepes on the wild host
(mother-of-cocoa) does not differ significantly from the
number laid on citrus, indicating that the two hosts are about
equally suitable to the insect which, thus, can shift from one
to the other without any significant change in the size of its
populations. These are significantly enhanced coming from
the wild to the cultivated host.

2. Citrus is therefore an excellent host species for Diaprepes. In
fact, in Florida when the insect became established, it never
attacked sugarcane, but became a serious pest of citrus. In
agroecosystems of Puerto Rico this species may serve as a
breeding site, maintaining the Diaprepes population at a high
level. Pigeon peas, papaya and vegetables contribute
presumably much less to the abundance of that insect.
3. Pigeon pea proved to be more suitable than the wild host,
although not as good as citrus. It topped mother-of-cocoa for
all the criteria considered (Table 6). It does not withstand well
the attack of Diaprepes, and especially young plants may be
severely damaged. The plant is very prone to develop fungi
which will damage the eggs of the insect at an early stage.
4. Papaya is unquestionably a poor host and may contribute only
little to the population of the insect. That host was worst for
all the criteria considered.

TABLE 1. Biological criteria (fecundity, oviposition, incubation, hatching success) related to Diaprepes abbreviatus (L.) reared
and maintained on orange leaves (Citrus sinensis [Osbeck]). Temperature 75"F (23.8*C), R.H. 80%.

(11 Oct-)( 3 Nov.-)( 7 Dee )(
(29 Nov.)( 3 Dec. )(23 Feb. )(
( 1982 )( 1982 )( 1982 )(

1. Total eggs laid in
2. Duration of oviposition
3. Average daily oviposi-
4. Average duration of in-
5. Number of live births
6. Percent hatch
7. Number days lived in

3 Nov.-)(7 Dec 82-)(7 Dec.-)(3 Nov.-)
6 Dec. )(2t, Jan. )(31 Jan.)(15 Mar.)
1982 )( 1983 )( 1983 )( 1983 )

144 230 225 655 274 1544

26 13 20 12

10.26 11.07 11.50 18.75

11.20 15.00 24.00 22.60

901 43 72 103
55.75 29.86 31.30 42.70
41 83 78 31

34 10 133

19.26 27.40 10.80

24.60 24.60 18.70

73 43 645
11.14 15.60 11.70
51 53 34

TABLE 2. Biological criteria (fecundity, oviposition, incubation, hatching success) related to Diaprepes abbreviatus (L.) reared
and maintained on papaya (Caica papaya [L.]). Temperature 75"F (23.8C), R.H. 80%.

(P-P-A to)
(P-P-G )
( July 2,)
( 1982 )

(P-P-A to E)
(August 2. )
( 1982 )


P-P-A lib )
Oct 11 to)
Oct 28, )
1982 )

1. Total eggs laid in la-
2. Duration of oviposition (days)
3. Average daily oviposition
4. Average duration of incuba-
5. Number of live births
(. Percent hatch
7. Number days lived in la labo-


P-P-A to)
P-P-G )
(May 14,)
( 1982 )















TABLE 3. Biological criteria (fecundity, oviposition, incubation, hatching success) related to Diaprepes abbreviatus (L.) reared
and maintained on pigeon pea (Cajanus indicus (L.]) leaves. Temperature 75"F (23.8"C), R.H. 80%.

(7 Oct.82)(18 Oct.-) (6 Dec.-)(18 Dec.-)(18 Oct )(18 Oct.)
(25 Jan. )( 6 Dec. ) (17 Jan.)(23 Dec. )(11 nov.)( 3 Dec.)
( 1983 )(- 1982 ) ( 1983 )( 1982 )( 1982 )( 1982 )

Total eggs laid in laboratory
Duration of oviposition
Average daily oviposition
Average duration of incubation
Number of live births
Percent hatch
Number days of adult life in

370 143



125 21 10
13 2 7
9.61 10.50 1.42
15 16.50 -
3 8 4
2.40 38.00 25.00

TABLE 4. Biological criteria (fecundity, oviposition, incubation, hatching success) related to Diaprepes abbreviatus (L.) reared
and maintained on "mother-of-cocoa" (Gliricidia sepiumJacq.] Steud.). Temperature 75"F (23.8"C), R.H. 80%.

( P-MR-A-1-a ) (P-MR-11-c ) (P-MR-.-d )
(21 Oct.- 17 Dec) (7 Dec 82-14) (7 Dec 82- )
( 1982 ) (March 1983 ) (5 April 1983)

1. Fotal eggs laid in laboratory 149 955 385
2, Duration of oviposition 6 73 119
3. Average daily oviposition 24.80 13.08 3.23
4. Average duration of incubation 17.30 19.19 16.80
5. Number of live births 45 269 112
6. Percent hatch 30.20 28.16 29.90
7. Number days of adult life in 53 94 124

TABLE 5. "t" values of all the comparisons and their significance. Vagility and survival of Diaprepes abbreviatus (L.).
Temperature 75F (23.8*C), R.H. 80%.

Biological criteria

Host tabulated t Degrees
plant 5% 1% freedom



1. Focal eggs laid in laboratory

2. Duration of oviposition period

3: Average daily oviposition

4. Avt-'rage duration of inIcubation

5. Number of live births

(J. Percent hatch

7. loLal days lived in laboratory

Mother-of-cocoa )
Orange leaves2 )
Mother-of-cocoa )
Orange leaves )
Mother-of-cocoa )
Orange leaves )
Mother--of-cocoa )
Orange leaves )
Mother-of-cocoa )
Orange leaves )
Mother-of-cocoa )
Orange leaves )
Mother-of-cocoa )
Orange leaves )



2.3b 3.49

2.36 3.49

2.36 3.49

2.36 3.49

2.36 3.49

2.36 3.49

2.36 3.49



3. 10"





-. siAnificanc at 5% level; 1/ Gliricidia sepium (Jacq.) Steud 2/ Citrus sinensis Osbeck


TABLE 6. "t" values of all comparisons and their significance. Vagility and survival of Diaprepes abbreviatus (L.).
Temperature 75F (23.80C), R.H. 80%.

Host Ta

Biological criteria

ibulated t Degrees
5% 1% freedom

Calculated "t"


1. Total eggs laid in laboratory Orange leaves) 2.36 3.49
Pigeon pea

Orange leaves) 2.36
Pigeon pea )

2. Duration of oviposition pe-

3. Average daily oviposition

4. Average duration of incuba-

5. Number of live births

6. Percent hatch

2. 44*


Orange leaves) 2.36 3.49
Pigeon pea )

Orange leaves) 2.36
Pigeon pea )


Orange leaves) 2.36 3.49
Pigeon pea )
Orange leaves) 2.36 3.49
Pigeon pea )

7. Total days lived in laboratory Orange leaves) 2.36 3.46
Pigeon pea )




2.7 6-

I significant at 5% level Orange: Citrus sinensis Osbeck Pigeon pea: Ca anus indicus L.

TABLE 7. Biological criteria (fecundity, oviposition, incubation, hatching success, longevity) related to the sweet potato
weevil Cylasformicarius on sweet potato (Ipomea batatas [Lam.]).

1 2' 3 4 5 7' 9 '10 '11 '12 '13 '14

1. Fotal eggs laid in the
2. Average duration of ovi-
position period
3. Fotal days lived in labo-

I 1 1

54 19 19

'253' '177' 253' 177253'253'127'253'253'177'223'253'253'
'253' 253'253'177' '253'253'127'253'127'253'253'177'253'

1. Alfieri, S.A.,Jr. 1972. Status report on the sugarcane rootstalk borer weevil.
Citrus Ind. 2:11, 30.
2. Beavers,J.B., and A. G. Selhime. 1975. Population dynamics of Diaprepes
abbreviatus L. in an isolated citrus grove in central Florida. J. Econom. Entomol.
3. Beavers, J.B., R.E. Woodruff, S.A. Lovestrand, and W.J. Schroeder. 1979.
Bibliography of the sugarcane rootstalk borer weevil, Diaparepes abbreviatus. ESA
Bulletin: Vol 25, No.1.
4. Bonnefil, L. 1971. Biological interactions ofEmoascaphaseola Oman with
selected leguminous hosts. Ph.D. thesis. Dis. Abst.
5. Domey, I. 1979. Push to bar "vaquita" from U.S. poses no problem for
island plant exports. The San Juan Star, Tuesday, May 29.


6. Norman, P.A.'et al. 1974. Feeding damage to five citrus rootstalks by larvae
of Diaprepes abbreviatus (Coleoptera, Curculionidae) Fla. Entomol. 57:296.
7. Price, P.W. 1975. Insect Ecology. Wiley Inter-Science Publication. John
Wiley and Sons, New York.
8. Simmonds, F.J. 1953. Insect pests of sugarcane in the French Antilles. Top.
Agric. 30:122-7.
9. Schesler, W.C. 1980. Statistics for the biological sciences, second edition.
Addison Wesley Publishing Co., Buffalo, NY.
10. Wolcott, G.N. 1936. The life history of Diaprepes abbreviatus at Rio
Piedras, P.R. J. Dept. Agric. P.R. 17(3):265-270.
11. Woodruff, R.E. 1964. A Puerto Rican weevil new to the United States (Col-
eoptera, Curculionidae). Fla. Dept. Agric., Div. Plant and Entomol. Circ. 30:1-12.



Beekeeping in the Caribbean

Richard A. Breyer
Box 157, Stephenson, MI 49887

The potential for the production of honey and related pro-
ducts for the Caribbean is great. The climate, flora and de-
mand for an economical, locally produced sweetener provide
an ideal setting for expanded production. Start-up and on-
going expenses are minimal compared to most agricultural
endeavors. Although management is needed, anyone with a
desire can learn the necessary skills. Recently, a technical
assistance program between Dominica and Michigan State
University catalyzed developments for the industry on that

E. Harris and T. Sorhaindo
Ministry of Agriculture
Roseau, Dominica

island. Field level Agriculture Extension Agents from the two
countries worked together to identify potential producers,
provide training, and encourage the development of producer
support systems. Such a technical assistance program could be
continued with Extension Agents and experienced volunteer
beekeepers who would help local beekeepers improve their
skills, create new products and reteach other beginning
beekeepers. A joint program to pool expertise and interests
could be developed and is worth exploring.

A sweetner is a universal need. The honey bee is, and will con-
tinue to be a source of sweetner. The honey bee has the ability to
successfully make a sweetner from the nectar of flowers with but
limited expense and guidance from man.
It appears there is room for all Caribbean nations to increase
production of honey and bee products. Their setting is great; the
opportunity exists that this industry can become an important
part of all Caribbean nations' small farming efforts. The Carib-
bean has the flora, climate, and most important, is virtually a
disease-free environment for the honey bee. The Africanized bee
has not invaded most of the Caribbean Island nations. These
distinct advantages give a solid base upon which to build.
The economics of honey production for family use are
favorable. Honey can be used as a sugar substitute. Based on the
Dominican honey prices of September 1983, and the potential
production from that nation's bee industry, a colony of bees
could produce approximately 200 pounds per year with a retail
value of over $1,000 Eastern Caribbean currency (EC). Even at
the depressed U.S. prices of honey, the value of one colony in
production in Dominica would be approximately $540 EC.
Typing honey would give these nations the opportunity to in-
crease foreign exports. There is a demand in other nations of the
world for tropical honey. Types of honey, or blends of tropical
honey could become a novelty produced in the Caribbean and
marketed in other nations of the world. Good marketing efforts
are necessary and need further development. Becoming a
beekeeper is rather inexpensive, especially when we compare it to
most other agricultural endeavors. At present in the Caribbean,
honey production is the most economical, reliable agricultural
enterprise. The basic equipment, a hive tool, smoker and veil,
costs about $65 EC $24 U.S. The cost of a complete hive is about
$400 EC, or $148 U.S. Therefore, the basic equipment necessary
for one hive is approximately $465 EC or $172 U.S. Production
from one hive the first year should range between 6 and 10
gallons. The second year the production should increase to its full
potential range of 12 to 20 gallons. At the current price of $75 EC
per gallon, this would indicate a return to a Dominican
beekeeper of a range of $1,400 to $2,250 EC, or $521 to $833
U.S. per hive.
After the basic equipment expenses and extractor rental, the
cost of production would be $467 EC or $173 U.S. This would
give a net over a two-year period of $348 to $660 U.S. These
figures do not take into consideration any transportation charges,
home use of honey, and other miscellaneous costs such as bottles.


Currently, discarded beer and liquor bottles are used. This
substantiates the fact that the small farmer, by integrating a col-
ony of bees into his farming system, can increase the well being of
his family through the use of honey for his own family diet, by
selling it, or a combination of the two.
Beekeeping does not deplete the soil nor reduce the country's
resources. It adds to the well being of agriculture by its presence.
Trees produce more fruit, plants more flowers, and bees as
pollinators increase the success of most agricultural crops.
With a personal desire and persistence, most anyone can learn
the basic skills of beekeeping in just a few lessons. These basic
skills, along with the guidance of an experienced person such as
an Extension Bee Officer, makes success possible.
Early in 1983, Mary Andrews, Michigan State University Direc-
tor of International Extension Training, was contacted by Errol
Harris, Deputy Chief Agriculture Officer, Ministry of
Agriculture, Division of Agriculture, Dominica, for assistance to
revitalize and further develop the Dominican bee industry.
Therefore, my mission to work with existing beekeepers and to
train new beekeepers in Dominica developed.
My background is in general agriculture. In Michigan, my
responsibility is County Extension Director for Menominee Coun-
ty, Michigan. This is where beekeeping became a hobby for me.
The Upper Peninsula has a lot of agriculture and could be
classified as a area.
After arriving in Dominica, the local Extension Officers ar-
ranged a tour of the entire island so that I would become better
acquainted with their bee industry, agriculture and Dominican
people. Through these same officers, an awareness program using
radio, newspaper and word of mouth was conducted to identify
Dominicans that were interested in beekeeping. This was com-
pleted during the first week spent in Dominica. During this time
existing beekeepers were identified and a personal visit was made
to each to become acquainted, answer questions, discuss tech-
niques and their problems. We also talked about markets for
honey and determined local beekeepers' needs. A mailing list was
developed an an inventory of hives and equipment of each
beekeeper was completed. Information was also gathered to
determine how large the industry could expand. Based on these
visits and the information gathered, three sessions for the experi-
enced beekeepers were scheduled. A general session was held for
them to become acquainted and for me to present some tech-
niques that they may consider adopting. It appeared that
management should be refined before production would in-


crease. There was a problem with the wax moth that needed to be
addressed. Two additional meetings dealt with approved prac-
tices, discussed the potential of new marketing methods and
explained various honey products and how they were made. A
decision was made at one of the meetings to form a steering com-
mittee to develop a honey cooperative. Since that time, one has
been established by the Dominican beekeepers.
In another series of classes that ran concurrently with ex-
perienced beekeeping classes, those interested in becoming
beekeepers were given the opportunity to attend two different
class sessions. One series of classes was held during the morning
for those that were not employed and an identical session was
held late in the afternoon and on weekends for those that had
conflicting work schedules. All class sessions used slides, equip-
ment displays, demonstrations, and field trips as part of the
presentation. Each student had the opportunity to help collect
swarms and to work a hive. There were also demonstrations with
hands-on opportunity to make all equipment necessary to
become a beekeeper. A local beekeeper was trained and engaged
to demonstrate how to make a hive body, frames and foundation
with class members assisting to learn the skills. Class members did
construct their equipment.
Techniques in collecting a colony from a tree were
demonstrated and once the colony was collected it was given to
the student who found it. Swarms were also collected and became
the property of the persons) who discovered them. All class
members attending had the opportunity to learn a wide range of
these skills. Each session of the class grew larger in number of par-
ticipants, indicating a growing interest.
There are a large number of unmanaged wild colonies in
Dominica due to the hurricanes that devastated apiaries and the
land in 1979 and 1980. Also, because of a lack of management by
existing beekeepers, a lot of wild colonies were established from
swarms. These, of course, were of no great benefit and in some
instances, a nuisance to people.
The beginning beekeeper classes included Dominicans from all
walks of life. Bankers, youth, business people, small farmers and
even one gentleman 86 years of age enrolled in the beginning
course of study and completed it. An indication of the success of
this venture can be illustrated by the increase in the number of
hives and beekeepers. An example -one person, Charles Stevens,
had four hives established from swarms as a result of taking the
Beginning Beekeepers Course. He began the course without any
hives. A hive and the equipment had the value of approximately
$400 EC. Today the number of colonies found on Dominica has

increased from the original 405 in September of 1983 to over
1,200, according to Tony Sorhaindo who took an actual count in
September of 1984.
Prior to leaving Dominica, a curriculum and lesson plan was
developed for the Organization of American States (O.A.S.), of-
fering beekeeping training to Dominican 4-H youth. Also, a set
of slides was provided through the efforts of Tony Sorhaindo,
New Crops Extension Officer, Roger Hoopingarner, Entomology
Youth Programs, Apiculture and Crop Pollination Specialist of
Michigan State University, and myself, to be used by the instruc-
tor. There were 18 4-H youths who completed the more intense
three-month session taught by a local beekeeper and Tony
Sorhaindo. The Chief Extension Officer, Errol Harris, a
beekeeper himself, has offered each student who satisifactorily
finished the O.A.S. course assistance to secure his(her) own hive.
Most of the Dominican bee industry expansion this past year
was from finding and capturing colonies from hollow trees, cliffs,
buildings, etc., and by division of existing colonies.
Dominica and most of the Caribbean nations are free of disease
and the Africanized bee has not invaded the islands. Every con-
ceivable effort should be made to keep it that way. This is a small
farm industry that can develop from within a nation. Additional
skills in packaging, typing honey, queen rearing and marketing
are major needs. In addition, a package industry could be
developed for not only the Caribbean nations, but for export.
Central extraction and packaging of honey is important for both
domestic and foreign markets. Import constraints should pro-
bably be explored to keep the Caribbean nations free of disease
and the Africanized bee.
An existing monthly newsletter sent to all youth on the island
was expanded to include information on bees to help the youth
learn about the importance of bees and how to identify swarms,
wild colonies and to whom to report them.
The bee industry of Dominica is on the move. It was fun and
rewarding to be a part of what has happened and to assist in
guiding future efforts.

1. Breyer, R.A., R. Hoopengarner, C.A. Sorhaindo. 1983. Dominican
Beekeeping. 80 slides.
2. Gentry, C. 1982. Small Keeping Beekeeping. M-17.
3. Jaycox, E.R. 1981. Beekeeping in the Midwest. Circular 1125.



Etude de la Matiere Organiques des Sols

par Fractionnement Granulometrique

1 Decomposition au Champ d'un Compost Enfoi

dans Plusieurs Types de Sols des Antilles*

M. Brossard, J. Balesdent, C. Feller
A. Plenecassagne and J. F. Turenne
ORSTROM BP 81, Lab. Matieres Organiques des Sols
97201 Fort de France (Martinique)

Les auteurs presentent une methode d'etude de la matiere
organique du sol qui permet, par granulometrie, de separer
trois fractions vegetales et une fraction organo-minerale.
Son application a une etude cinetique de la decomposition
annuelle d'un compost dans plusieurs types de sols met en
evidence que les seules variations significatives observees con-
cernent les fractions vegetales. A titre de comparison, les

autres techniques habituellement utilis~es pour I'etude de la
matiere organique des sols (extractions chimiques ou
hydrolyses acides) ne font apparaitre aucune variation
significative des formes de l'humus et de l'azote organique.
Mots-cles: Matiere organique du sol, fractionnement
granulometrique, formes humus et azote, vertisol, sol fer-
siallitique, sol peu evolue sur ponce.

*Recherche menee avec l'aide d'un financement CORDET 1981 : action
"Recyclage de la Matiere Organique."

Les resultats presents font parties de recherches visant a
valoriser les residus organiques (ruraux ou urbains) en agronomie.
En Martinique et en Guadeloupe, la culture de canne a sucre
permet de disposer de residus organiques sous forme de bagasse
et de vinasse. Les cultures maraicheres qui se sont fortement
developp6es depuis une dizaine d'annees dans ces deux miles indui-
sent une diminution du stock organique du sol ce qui, a terme, ris-
que de modifier Fensemble des proprietes physiques chimiques et
biologiques du sol. Aussi des essais au champ ont ete mis en place
dans plusieurs situations pedologiques afin de tester l'effet d'ap-
ports annuels de bagasse compostee sur quelques proprietes du sol
et en particulier sur I'evolution du stock organique.
L'etude comporte un suivi pluriannuel pour I'estimation du
stock organique et un suivi saisonnier (la premiere annie) pour la
measure de la cinetique de decomposition du compost enfoui. Ce
sont les resultats de premiere annie qui sont presents ici.
Les methodes les mieux adaptees a l'Ftude de la cinetique de
decompostion de matiere vegetale enfouie et de son incorpora-
tion aux matieres organiques du sol mettent en oeuvre l'utilisa-
tion de materiaux vegctaux marques (14C et/ou 15N). Pour les
residus de rcolte en milieu tropical on peut citer les travaux de
Jenkinson et Ayanaba (1977), Sauerbeck et Gonzalez (1977),
Feller (1981) et Feller et al. (1983).
Toutefois, ces methodes sont couteuses et difficiles d'utilisa-
tion. Par ailleurs, les techniques habituelles de caracterisation des
matieres organiques du sol sont de nature chimique (extractions
acido-alcalines et hydrolyses acides) et ne permettent pas de
distinguer les fractions vegetales de la matiere organique du sol
de l'humus du complex organo-mineral. Des separations
prealables densimetriques a l'aide de liqueurs denses organiques
(Duchaufour et Jacquin, 1966) ou minerales (Dabin, 1971) sont
parfois utilisees pour isoler les residus vegctaux "libres" de la
matiere organique "liee" (humus ss.). Ces methodes offrent
toutefois l'inconvenient d'etre soit, peu efficaces pour cette separa-
tion, soit de solubiliser avec les reactifs organiques ou mineraux
utilises une fraction des residus vegetaux et/ou de I'humus.


Depuis quelques annees se multiplient les travaux sur la
matiere organique des sols A partir de methodes bases sur de
simples fractionnements granulometriques (ou parfois granulo-
densimetriques) du sol sous eau (par ex. Bruckert et al., 1978;
Feller, 1979; Ladd et al., 1977; Tiessen et Stewart, 1983). L'un
des objectifs de ces recherches est de separer le mieux possible les
fractions vegetales (a divers degrees d'humification) du complex
organo-mineral et des composes hydrosolubles du sol. Nous il-
lustrons ici l'interet de cette demarche pour l'etude de la cineti-
que de decomposition d'un compost enfoui dans divers types de
sols tropicaux (Antilles).
A titre de comparison et de complement les matieres humi-
ques (Dabin, 1971) et I'azote-amine (Bremner, 1965) de sols sont
egalement doses.


L'experimentation agronomique
L'tude est menee en Martinique. Elle consiste en une etude par
couples : comparison sur differences stations de parcelles
cultivees en aubergine ou tomate, ayant requ ou non du compost.
Les differences stations, essais, et resultats agronomiques sont
resumes dans le tableau 1. Les donnees detaillees sont dans :"Ac-
tion CORDET, Recyclage de la Matiere Organique" (1984).

Les Sols
Trois types de sols sont studies : vertisol, sol fersiallitique et sol
peu evolue sur ponce.
Ils sont dcrits par Colmet Daage et Lagache (1965). Les
caracteristiques des horizons (0-20 cm) des sols des parcelles
suivies apparaissent dans le tableau 2. Les prelevements (0-20 cm)
sont effectues a la beche : environ 50 repetitions par traitement
pour le temps 0 et 20 repetitions ensuite (environ 60 kg de terre),
analyse sur une aliquote (environ 5 kg) tamisees a 2 mm.


Le Compostage
Il est mene en aerobie (3 mois) partir d'andains* retournes
reglierement (3 semaines) forms de bagasse additionn&e de
vinasse (neutralisee ~ la chaux) et d'engrais azotes. Les elements
solubles ne sont pas recycles. Le compost obtenu (tableau 3) est
former 80% de debris vegetaux de tailles superieures a 2 mm. Son
rapport C/N est de 49 et la teneur en Matieres Humiques Totales
(extraction Na4 P207 0, 1 M + NaOH O, 1, pH 12) est de
27,6%. Ce compost est riche en cendres (37%) et ses teneurs en
K (5 %o) et Ca (6%o) sont relativement levees par suite des ap-
ports de vinasse et de chaux.

La Matiere Organique du Sol
Fractionnement granulometrique : separation de fractions
vegetales, minerales, organo-minerales et solubles.
La methode est modifiee de celle de Feller (1979), avec utilisa-
tion d'ultra-sons, et consiste a separer par agitation et tamisages
successifs du sol sous eau a 2000, 200 et 50pim les fractions
suivants (Fig. 1):
1. Les fractions de tailles superieures a (F >50) dans les-
quelles la matiere organique se pr6sente essentiellement
sous forme de residus vegetaux (FO-2000, FO 200-2000,
FO 50-200,) a diverts degrees d'humification. De facon
simplifiee, dans la suite de ce texte, ces fractions seront
dites "fractions vegctales."
2. Une fraction dite organo-minerale (Fo-50) de taille 0-50
Jm composer essentiellement de micro-agregats organo-
3. Une fraction dite "hydrosoluble" (W) correspondent aux
eaux de fractionnement a teneur negligeable en C et N
dans cette etude et don't il n'est pas tenu compete.
Une bonne separation entire les fractions F > 50 et F (0-50) n'est
possible que si les agregats organo-mineraux de tailles superieures
a 50 Jm sont detruits. Cette destruction est obtenue par agitation
du sol sous eau (2 h) en presence de billes de verre, suivi, si
necessaire, d'un traitement aux ultra-sons (26 Khz, 10 mn).
Pour les fractions de tailles superieures a 50 jm, une separation
en fractions organiques (FO) et minerales (FM) peut etre faite
manuellement par agitation de melange et entrainement par
l'eau de fractions vegetales legeres. La separation est en general
pour F 50-200. Aussi, dans ce travail la separation FO-FM pour F
50-200 n'a pas et6 effectuee.

Extractions des Matieres Humiques Totales MHT: la methode est
celle de Dabin (1971) sur sol tamise a 2mm. Trois extractions suc-
cessives sont faites par H3P04 2M (acides fulviques libres AFL et
matieres legeres ML) NA4P207 O, 1M (matieres humiques totales
pyro. MHTp) et NaOH O, IN (matieres humiques totales soude
MHTs) respectivement. Ne seront presents ici que les resultats
correspondent a la some MHTp + MHTs.

Dosage de la-azote a-amine, N-aNH2 : la methode, Bremner
(1965) consiste en une hydrolyse acide du sol 0-2 mm (HCI 6N,
12 h) et du dosage des fractions suivants : azote ammoniacal
(N-NH2), sucres amines (N-hexo.) et azote insoluble (N-ins.).
Ne sont presents ici que les r6sultats de la fraction dominant

TABLEAU 1. Caracteristiques generales des differentes stations et des essais
etudi6s. Resultats agronomiques.

Localisation Ste Anne Lareinty Precheur
Pluviom6trie moyenne 1400 1800 1500
annuelle (mm)
Type de sol vertisol sol sol peu 6volue
fersiallitique sur ponces
Culture aubergine aubergine tomato
Fertilisation (Kg/ha)
P205/K20 /N 250/900/540 250/900/540 125/380/250
Traitement (a) T BC T BC T BC
Dose moyenne
compost enfoui 0 20 0 20 0 20
Rdt 16re anne 117 122 104(xx) 10,0() 107(xx) 9,4(xx)
(fruits T/ha)
(x) T = traitement temoin (sans compost)
BC = traitement avec bagasse composite enfouie
(xx) fletrissement bacterien ou cryptogamique

TABLEAU 2. Principals caracteristiques physiques, mineralogiques et chimiques
des horizons de surface (0 20 cm). Valeurs moyennes.

Station n 2 3 4

Type de sol

Pluviometrie moyenne
annuelle mm ,
Analyse mecanique % (vm)
A (0-2)
LF (0-20)
LG (20-50)
SF (50-200)
SG (200-2000)
Mineraux argileux


pH eau

C %,

N X-


Sx 100

Vertisol Sol fersiallitique

1400 1800

65 56
12 23
5 7
13 9
6 4

Smectite Smectite



6,2 .5,9
5,2 5,0

15,7 .. 18,2
.1,45 1,84
10,8 9,9

42,0 30,0

Sol.peu evolut
sur ponces



Halloysite ou
metahalloysi te






da = density apparmnte, c carbon, N azote, CEC w capacity d'echange cationique,
S = some des bases echangeables

Dosages C et N : c et N sont doses par voie seche a l'aide d'un
Analyseur Elementaire C,H,N,O,S, Carlo Erba mod. 1106.

*Pour 5 t de bagasse fraiche il faut 1,5 m3 de vinasse (neutralisee par 3,5
kg de chaux), 5 kg de sulfate d'ammonium, 5 kg d'uree, 1 kg de terre
(pour ensemencement).


TABLEAU 3. Composition du compost au moment de l'enfouissement.

C N C/N Cendres Fe203 A1203 Ca Mg K Na
%. % pyro soude o %0 % .o %.

343 7.08 49 2.5 25.1 378 33.4 53.6 5.73 0,56 5.37 0.OQ

(t) MHT : natiCres humiques totales extraites au pyrophosphate Na 0,1 M pyroo) puis a la soude
0.1 N (soude) exprimnes en carbon % du carbon total.


FIG. 1. Schema du fractionnement granulometrique.

Separation des fractions
Tamisage sous eau 3 A2000
Agitation de 50 g M0 sol
+ 300 ml 120
+ 3 bills de verre. 50 t/3m3
Ultra-sons 6 33, 50+D m
Tanis 200 p --

Tamis 50pm --

Tailles (p-) Fractions
20D00 F 20i FO 2000 debris irgtaux tr3s grossiers
2000 F 'FM 2000 gra.:er;

/FO 2D0-2000 debris vPgetaux grossicrs
2CO ZCM F 00-2000\M
5FO 50-2CO D bris vMgetaux fins
50 ZO F 50-200".
FH 50-Z00 sables fins

0 50 F 0-50 co,-plexe organo-mineral

W Fraction hydrosoluble
La some des fractions de tailles superieures A 50 pm est represented par :
F > 50 = F 2O00 + F 20-2C00 F 50-ZOO

FIG. 2. Variations saisonnieres des stocks organiques (0-20 cm), stations 2, 3 et 4.

Station Traltement
-O- T
---- T
,mg C-g-Isol T
t- BC

0 -0r- BC


130 200 300 400 T jour.

Variations saisonnieres des teneurs en carbon total de
l'horizon (0-20 cm)
Les teneurs determinees sur un prelevement moyen de
l'horizon (0-20 cm) incluent le sol (0-2 mm) plus les residus
vegetaux FO 2000 de talles superieures a 2 mm (donc le compost
au temps to, just apres son enfouissement).
Les variations saisonnieres sont representees Fig. 2.
On peut considerer, compete tenu de la variability de la measure
(liee d'abord a la variability des prelevements), que pour toutes:
les stations les courbes BC et TG se rejoignent a 200 jours. La
difference AC, a chaque instant entire BC et T des teneurs en car-
bone total represente-t-elle le carbon compost ("C-compost")
non encore mineralise?
La variability de la teneur en carbon total est due a
l'heterogeneite initial des sols independamment des traitements
("variabilite-sol") et a celle de la repartition du compost apres en-
fouisement ("variabilite-compost) (_1 mgC.g-'sol) et d'une
variabilite-sol (l-mgC.g-'sol). Cette derniere est independante
du traitement (Action CORDET, 1984).
Les differences entire BC et T des productivites vegetales donc,
probablement, des apports racinaires ne sont pas a prendre en
compete. En effect, pour la station 2 la productivity vegetale est
identique pour les deux traitements, et pour les stations 3 et 4 les
productivites vegetales sont tres faibles (fletrissements).
En conclusion, la difference AC1 integre l'ensemble des
variabilites de I'experimentation, en particulier la "variabilite-sol"
qui est independante des traitements. Celle-ci ne devrait donc
pas etre prise en compete pour I'etude de la decomposition du
compost. Par ailleurs, il ne semble pas y avoir d'effet specifique
du compost sur le developpement racinaire. Aussi, nous mon-
trons ci-dessous que le "C-compost" peut etre estime a chaque in-
stant par la difference AC2 entire BC et T des fractions de tailles
superieures a 50 jm pour les stations 2 et 3, et par la difference
AC2 entire BC et T des fractions organiques superieures a 200 jm
pour la station 4.

Decomposition du compost : etude par fractionnement
granulometrique de la matiere organique du sol.
Les resultats (mgC.g-' sol) sont detailles dans le Tableau 5, et
presents de fapon synthetique sur la Fig. 5 (AC2 en pourcentage
de AC2 initial).


Nature des fractions et rapports C/N: Pour les vertisol et sol fer-
siallitique (St. 2 et 3), l'observation a la loupe binoculaire et au
microscope confirm que la matiere organique de F > 50 est
essentiellement consituee de debris vegetaux a divers degrees
d'humification et ne content pratiquement plus d'agregats
organo-mineraux. Les rapports C/N de ces fractions sont
superieurs a 15 (compris entire 15 et 35) done tres different du
rapport C/N de F 0-50. Cette derniere est surtout formee de
micro-agregats, son rapport C/N varie de 8 a 10. En premiere ap-
proximation la coupure a 50 pam spare done bien les residus
vegetaux plus ou moins humifies du complex organo-mineral.
Par contre, pour le sol peu evolue sur ponce (st. 4) on ne peut
assimiler le carbon des fractions F > 50 a celui des seuls residus
vegetaux car:

1. Les agregats organo-mineraux sont plus stables et contami-
nent en particulier la fraction F-50-200 (confirmation par
les rapports C/N compris entire 10 et 12).
2. Les sables ponceux ont des teneurs en carbon non
negligeables et des rapports C/N bas (9 a 11) indiquant
une absorption de composes humiques.

Estimation du "C-compost" restant a chaque instant : Stations 2
et 3 Nous venons de voir que la coupure a 50 pm spare bien le
complex organo-mineral des residus vegetaux. Par ailleurs, il est
necessaire de contr6ler que le "C compost" n'enrichisse pas la
fraction F 0-50 au course de la decomposition.
Lors d'etudes anterieures (Feller, 1981) il a ete montre qu'au
course de la decomposition annuelle d'un compost marqu 14C les
transfers vers la fraction 0-50 /pm etaient faibles et non decelables
par les seuls dosages chimiques. Le Tableau 4 present les teneurs
(mgC.g-'sol) en carbon des fractions F 0-50 pour l'ensemble des
traitements (st 2 et 3). II n'apparait pas, pour un meme type de
sol, et toutes dates de measures confondues de differences inter-
parcellaires notables. Les moyennes saisonnieres varient de 10%
pour tous les traitements ce qui confirm I'absence de variability
lie a un effet compost pour cette fraction.
On peut done estimer le "C-compost" restant a chaque instant
par la difference AC2 entire BC et T des teneurs en carbon de
l'ensemble des fractions de tailles superieures a 50 jm (F > 50).
Des lors, la variability de la measure n'est que de 20% du com-
post initial.



TABLEAU 4. Variations des teneurs (mg C.g sol) de la fraction F 0-50 pour les TABLEAU 5. Teneurs en carbon, mgC/g sol, et rapports C/N des fractions gran-
differentes stations et different traitements. ulometriques superieures a 50 mm pour l'ensemble des traitements.

Station date F 0-50 (ma.C.g-lsol)
S pr6levement -------- ---------------------- --
(t jours) T BC
2 t 6 9,8 12,6
t 102 12,0 11,5
t 188 12,5 12,5
t 230 12,2 12,3
t 381 12,5 13,3
moyenne 11,8 1,14 12,4 0,65
3 t 4 15,4 17,9
t 90 14,1 15,9
t 258 17,0 16,3
t 425 12,8 14,0
moyenne 14,8 + 1,8 16,0 1,6
4 t 7 4,2 3,l
t 64 3,6 5,2
t 102 3,5 4,1
t 230 3,4 3,9
t 396 4,2 3,9
moyenne 3,8 0,4 4,0 0,75

Station 4 L'observation des fractions et leurs rapport C/N mon-
trent que l'on ne peut considerer l'ensemble des fractions F > 50
comme n'etant former que de residus vegetaux. Aussi AC2 =
"C-compost," sera ici representE par la difference a chaque ins-
tant entire T et BC, de la some des fractions FO 2000 + FO
200-2000. Le reste, FM 200-2000 + F 50-200 + F 0-50, represen-
tant I'ensemble des fractions organo-minerales et minerales du
sol. Dans ces conditions pour la station 4, le "C-compost" est
estimE par defaut.

Cinitiques de decomposition du compost et
transferts de matieres

La Fig. 3 regroupe les variations des differences (BC-T) des
teneurs en carbon de chaque fraction, et ce, pour les 3 stations.
Pour permettre la comparison des stations qui n'ont pas la
meme teneur initial en C-compost dans l'horizon 0-20 les
resultats sont exprimes en "C-compost" pourcentage de
"C-compost" initial de I'horizon 0-20 (AC2 initial).

Stations 2 et 3
1. Elles presentent un comportement analogue mais different
nettement de la station 4 ou la decomposition du compost
est beaucoup plus rapide (Fig. 3a et b).
2. La decomposition de C-compost (Figg. 3) suit une loi ap-
proximativement lineaire d'equation :
"C-compost" = 99,0 0,264 t C en pourcentage "C-com-
post initial t en jours
3. Selon la taille des fractions, les variations sont tres
differentes. La comparison des courbes FO 2000 et FO
200-2000 (Fig. 3a et b) indique pour les 100 premiers
jours, non seulement un mineralisation de C-compost
(diminution de F > 50), mais aussi un transfer de carbon
des fractions superieures a 2 mm vers les fractions de taille
200-2000 .m (division du compost).
4. Les variations pour FM 200-2000 et F 50-200 sont faibles ce
qui implique probablement un faible transfer de
"C-compost" initial vers ces fractions.
5. Le rapport "C/N-compost" (Fig. 4) passe d'environ 45 to
a 17 a 200 indiquant une forte humification du compost
residuel a 200 jours. Cette variation peut etre exprimee par
l'equation :
"C/N-compost" # 42,9 -0,172 t + 2,83 10=t2 (t en jours)


Station Date de T C
prflvewent Fractions
(t jours) igC/9 ol C/N mgC/g sol C/N

t6 FO 2000 0,19 30,0 .,78 56.0
FO 200-2000 0.46 26,4 2.65 37.6
FM 200-2000 0,31 14,6 0,20 14.8
F 50-200 0,96 18,6 1,36 19,6
Total F 50 1,92 19,7 6,99 34,7
t10? FO 2000 0,14 24,0 0,41 27,0
FO 200-2000 0,96 17,3 3,63 28,5
FM 200-2000 1.33 11,6 2,11 15.0
F 50-200 1,98 16,0 2.52 13,8
Total F 50 4,41 14,6 8,67 18.7
t188 FO 2000 0,57 16,8 1,08 24,0
FO 200-2000 0.52 16,8 2.27 18,6
FM 200-2000 1.24 12,1 0.49 15.1
F 50-200 2,50 17,0 2,75 15.2
Total F 50 4,84 15,3 6,59 17.4
t230 FO 2000 0,33 18,2 0.54 20,8
FO 200-2000 0,49 20,7 1,56 21,9
FM 200-2000 0,42 16,5 0,57 17,5
F 50-200 1,70 16,2 2,02 15.3
Total F 50 2,94 17.2 4,69 17,5
t381 FO 2000 -
FO 200-2000 0.81 21,7 0,60 18,4
FM 200-2000 0,58 21.2 0.55 11.1
F 50-200 1.32 28,0 2,38 15,3
Total F 50 2,71 24,4 3,53 15,0
3 t4 FO 2000 0,25 39.5 1,21 59.5
FO 200-2000 0,35 14,5 0,97 21,6
FM 200-2000 0,39 15.1 0.59 17,0
F 50-200 2,47 16,2 2.17 18,2
Total F 50 3,46 16,6 4,94 22,6
t90 FO 2000 0,11 32,7 0,39 45.1
FO 200-2000 0.46 18,0 1,35 22.3
FM 200-2000 0.52 23.1 0.51 18,8

F 50-200 1,81 17,1 2,71 16.4
Total F 50 2.90 18,3 4,61 17,7

t258 FO 2000 0,34 29,2 0,75 18,1
FO 200-2000 0,27 20.1 0,21 21,1
FM 200-2000 0,62 21,0 0,45 19,3
F 50-200 1,99 19,4 1.94 18.3
Total F 50 3,22 20,5 3,35 19.1
t425 FO 2000 0.58 27.4 0.58 26.2
FO 200-2000 0,76 21,5 0,76 19,4
FM 200-2000 0,41 14,5 0.42 13,2
F 90-200 2,22 13,2 1,98 16,2
Total F 50 3,97 15,6 3,74 17.3
4 t7 F 2000 0,17 31.7 1,51 51.0
FO 200-2000 0,55 17,8 1,24 17,9
FM 200-2000 0,93 8.7 1,69 13,4
F 50-200 1,23 1 1.30 14,3
Total F 50 2.88 11.7 5,74 18,2
t64 FO 2000 0,36 24,5 0,33 36.6
FO 200-2000 1.11 22,6 0,94 17,6
FM 200-2000 1,20 11,3 0,82 11.8
F 50-200 1,51 14,9 1,43 15.4
Total F 50 4,18 15,4 3.52 15,7
1102 FO 2000 0.15 19,3 0.15 29.2
FO 200-2000 0,44 13,8 0,78 17.3
FM 200-2000 1.09 9,6 1,12 12,5
F 50-200 1,06 10,2 1,42 11,6
Total F 50 2.74 10,7 3,47 13.5
t230 FO 200 0,3' 19,3 0,27 19,4
FO 200-2000 0,70 14.8 0.61 16.0
FM 200-2000 0,96 6.5 0,63 5.7
F 50-200 1.21 12,0 1,26 14,0
Total F 50 3,23 10,3 3,77 14,9
F396 FO 200 0,76 18,6 0,57 18,5
FO 200-2000 0.87 14,6 0,83 15,4
FM 200-2000 1,05 0.80 6,3
F 50-200 1,42 11,1 1.78 12.5
Total F 50 4,10 3.98 11,2

Station 4
1. La decomposition du compost dans le sol sur ponce est ex-
trement rapide, quasi total en 100 jours.
2. C'est peut-&tre le seul sol oi il y ait transfer de
"C-compost" vers les fractions minErales et organo-
minerales puisque la valeur AC3 (mgC.g-'sol) telle que:
AC3 = (CFM-200-2000+cF50-200+CFO-50)5B'-(CFM200-2000
passe de -0,33 (done proche de O) a to, a + 1,16 (t64),
0,96 (t102) 0,27 (t230) et -0,12 (t390). Ce transfer est
done sensible entire to et tlO0. On revient aux valeurs in-
itiales en une annee.


FG. 3. Repartition du carbone-compost dans les fractions superieures a 50 mm.


FO 2000

FO 200-2000

FM 200-2000

F 50-200

F> 50

C(% C initial)

50 3a

A A,?

) olvision
du compost


C(% C initial) St. 2
0 St. 3

St. 4
30 3c

10 *



0 I
o ( \ 3e

0) \

A .-A *- t Jours
0 100 200 300 400

FIG. 4. Variations des rapports C/N des fractions superieures a 50 mm ou des frac-
tions superieures a 200 mm.


I gender St. 2, BC

0 St. 3, BC

Some des fractions sup6rieure s 50 pm

Some des fractions suptrieures A 200 pm


t jours
auv2 nn Annc~

x \

\ \

30 5


FIG. 5. a) Variations saisonnieres de la teneur moyenne en composes humifi6s
(MHT % CT) des sols (0-2 mm).





3 6Ct- eC

4 T





Etude des formes de l'humus et de l'azote organique
Les resultats sont presents sur la Fig. 5 et exprimes pour les
matieres humiques (MHT) totales en pourcentage C total (sol 0-2
mm) et pour l'azote a-amine (Na-NH2) en pourcentage N total
(sol 0-2 mm). Y a-t-il variations saisonnieres des formes de
'humus et de I'azote organique par suite d'un apport de com-

Etude MHT (Fig. 5a) : quel que soit le type de sol, jusqu'a 300
jours, on n'observe aucune variation significative entire les
traitements T et BC. La seule variation notable concern a t396
I'augmentation de MHT pour le traitement BC, station 4. Cette
augmentation relative ne correspond pas a la period de transfer
(0-200 jours) de C-compost vers les fractions minerales et organo-
minerales (cf. 3.2.b). II est done difficile d'interprhter cette varia-
tion par un "effet compost" et la variability des prelevements et
des measures doit etre envisagee.

Etude N-a-NH2 (Fig. 5b) : Pour les memes raisons que ci-dessus
les variations qui sont relativement importantes sont difficile-
ment interpretables.

FIG. 5b) Variations saisonnieres de lazote aminE (N-aNH{ % NT) des sols
(0-2 mm).






01 0 200 300 400



Un fractionnement granulometrique du sol permet par com-
paraison entire traitements temoin T et compost BC de suivre la
decomposition in situ de l'apport organique.

Les vertisol et sol fersiallitique (stations 2 et 3) montrent une
meme evolution du compost dans le sol. La disparition de
P'amendement organique carbonn) suit une function lineaire et
est total en un an. Toutefois, il est possible de distinguer une
phase de division et de decomposition tres rapide de 0 a 100 jours
puisque le debris de tailles grossieres (superieures A 2 mm et
representant 80% de l'apport organique) ont complement
disparu a 100 jours et sont en parties retrouves sous forme plus
fine (200 2000 pm). Toutefois, l'incertitude des measures ne

permettent pas de deceler une augmentation de la fraction
organo-minerale (0-50 Mm) ni des variations significatives et/ou
interpretables des differentes formes de I'humus et de l'azote
organique au course de la decomposition de l'amendement organi-

Dans le sol peu evolue sur ponce (station 4) la decomposition du
compost est plus rapide. A 64 jours le compost a disparu totale-
ment des fractions de tailles superieures a 50 am, et on note un
transfer de C-compost entire 0 et 100 jours vers les fractions
minerales et organo-minerales, de tailles inferieures a 200 /m. La
difference entire T et BC redevient nulle au bout d'une annEe.
L'etude des formes de I'humus n'a pas permis de preciser la
nature des composes humifies concerns puisqu'aucune variation
n'est observe par cette methode dans l'intervalle de temps 0-200


1. Action CORDET. 1984. Le recyclage de 'la matiere organique. Rapp. mult.,
ORSTROM-Martinique, en course de redaction.
2. Bremner, J.M. 1965. Organic forms of nitrogen, in "Methods of soil
analysis" C.A. Black Ed., Am. Soc. of Agron., Madison, WI 1238-1255.
3. Bruckert, S., F. Andreux, A. Correa, KJ.M. Ambouta, et B. Souchier.
1978. Fractionnement des agretats applique A l'analyse des complexes organo-
mineraux du sol. Trans. 11th Int. Cong. Soil Sci. 6:88-89.
4. Colmet, Daage F. and P. Lagache. 1965. Caracteristiques de quelques
groups de sol derives de roches volcaniques aux Antilles frangaises. Cah.
ORSTROM, sir. PEdol. 3:91-121.
5. Dabin, B. 1971. Etude d'une methode d'extraction de la matiere humique
du sol. Sci. du Sol, bull. AFES, 1:47-63.
6. Duchaufour, Ph. et F. Jacquin. 1966. Nouvelles recherches sur I'extraction
et le fractionnement des composes humiques. Bull. E.N.S.A. Nancy 8(1):3-24.
7. Feller, C. 1979. Une methode de fractionnement granulometrique de la
matiere organique des sols. Application aux sols tropicaux a textures Grossieres, tries
pauvres en humus. Cah. ORSTOM, ser Pedol., 17:339-346.

8. Feller, C. 1981. Transormation de residus de recolte marques (paille C'4
N'", compost C'4) et devenir de i'azote-engrais (ure N'") dans un agrosystime
tropical. Rapp. mult. ORSTOM-Cadarache, 64 p.
9. Feller, C., M. Cheval, et F. Ganry. 1981. Decomposition et humification de
residus veg6taux dans un agrosysteme tropical. I. Influence d'une fertilisation azotee
(uree) et d'un amendment organique (compost) sur la repartition du carbon et de
I'azote dans different compartments d'un sol sableux. Agron. Trop. 26(1):9-17.
10. Feller, C., G. Guiraud,J.M. Hetier, and C. Marol. 1983. Study by size frac-
tionation of organic matter in a cultivated tropical soil fertilized with labelled crop
residues ('4C, "N) and urea "N. Inter. J. Trop. Agri. 1(2):123-130.
11. Jenkinson, D.S., and A. Ayanaba. 1977. Decomposition of carbon-14
labelled plant material under tropical conditions. Soil. Sci. soc. Am.J. 41:912-915.
12. Ladd,J.N.D.,J.W. Parsons, and M. Amato. 1977. Studies of nitrogen im-
mobilization and minerailzation in calcareous soils. I Distribution of immobilized
nitrogen amongst soil fractions of different particle size and density. Soil Biol.
Biochem. 9:309-318.
13. Sauerbeck, D.R., and M.A. Gonzalez. 1977. Field decomposition of
carbon-14 labelled plant residues in various soils of the Federal Republic of Germany
and Costa-Rica. In "Soil Organic Matter Studies," IAEA-FAO, Vienne, 1:159-168.
14. Tiessen H., andJ.W.B. Stewart. 1983. Panicle-size fractions and their use
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tion in size fractions. Soil Sci. Soc. Am.J. 47:509-514.



Foliar Analysis as a Diagnostic Technique

in Tropical Horticulture

G. A. Cahoon
Department of Horticulture
Ohio Agricultural Research and Development Center
The Ohio State University, Wooster, OH 44691

A brief history of the development of foliar analysis as a
diagnostic technique for horticultural crops is reviewed and
discussed. Terminology, together with a basic discussion of the
components necessary to operate a successful foliar analysis
program for growers, is presented. Some standard values, as

they relate to 'normal' growth of selected tropical and sub-
tropical horticultural crops, are listed.
Keywords: foliar analysis, plant analysis, leaf analysis, petiole
analysis', diagnostic techniques, plant nutrition, nutrient

Foliar analysis has been an active research procedure since the
late 1930's. Some of the early comprehensive studies of impor-
tance to us today were conducted on horticultural crops such as
citrus, apples, grapes, peach, tomato, and potato and others. The
goal of these studies, then, as well as now, was to develop a
method whereby the nutritional status of the plant can be ac-
curately determined. As we have gained knowledge and ex-
perience, developed equipment and techniques, fertilizer pro-
grams based upon foliar analysis have been devised which
resulted in increased production and quality. Early researchers
such as T. Wallace (Great Britain), P. Prevot (France), W.
Reuther (USA), H.F. Clements (USA), A. Kenworthy (USA), M.
Maume (France), C. Bould (Great Britain), G.T. Nightingale
(USA) have given us much insight into this procedure and
deserve credit as the pioneers in the field. The definition of foliar
analysis, as used here, includes the terms tissue analysis, leaf
analysis, petiole analysis, and plant analysis, somewhat inter-
changeably. Although it is possible to use rapid tissue tests, the
procedure is declining in popularity and is not developed or
discussed further in this presentation.

Modern Methods and Equipment
During this early period, chemical analysis procedures were
time-consuming, tedious and sources of considerable error. To-
day, although the equipment is relatively expensive, much pro-
gress has been made and it is possible to run accurate and rapid
analyses of many elements on a wide range of tissues. However,
accurate chemical analysis of a tissue is only one part of the
diagnostic technique we call foliar analysis. Sampling procedures,
including collection, preparation and interpretation of the data
are still vital components and the ultimate success of the tech-
nique generally depends on how accurately they are handled.
Depending upon the tissue and time of sampling, leaf age and
condition, drying and grinding procedures, etc., considerable
variability can be introduced and are major sources of error.
Regardless of the difficulties of past and present research,
much of the progress and development of current information on
nutrition of horticultural crops can be attributed to the use of
foliar analysis. For example, before the general use of foliar
analysis many fertilizer experiments were conducted to determine
the effectiveness of a given type and rate of fertilizer on yield and
quality of a crop. Yet because there was no 'common denom-
inator,' or means of judging the relative nutrient status of the
plant, much of the reference value was lost for anything but
localized conditions. On the other hand, through the use of foliar
analysis, the relationship between nutrient content of a specific


tissue, yield and quality has been utilized. This has been suffi-
ciently reliable from year to year and from one soil type or
cultural condition to another, that standards for many crops have
been developed. Conducting field fertilizer experiments today
without using foliar analysis is, in this author's opinion, almost
inexcusable. For the commercial fruit producer, failure to take
advantage of such an important tool is an invitation to failure.
Thus, within the scope of this discussion, some of the fundamen-
tal procedures will be discussed whereby both researchers and
growers can avail themselves of this technique.

Definition of Terms
Nutritional studies of individual elements indicate that defi-
ciencies or excesses can limit growth. However, it soon becomes
obvious to the researcher that the concentration of one element
within a plant cannot be changed very much without influencing
another to a degree that growth may be affected. The term used
for this is called nutritional interaction. Some of these interac-
tions become very dominant on certain crops. For example, the
relationship between potassium and magnesium on grapes is very
obvious in any studies with either element. In recent years,
studies on nutrient interactions have led to the development of
procedures such as the DRIS system (Diagnosis and Reconmmen-
dation Integrated System).
A definition of terms for all the nutrient elements as used in
this discussion can be defined as follows:
Deficient: Plants are in the deficient range if they show
visible leaf symptoms or distinctive decreases in yield and
quality can result.
Low: Plants are in the low range if the amount of an ele-
ment present in the plant is inadequate to produce op-
timum yield or quality.
Sufficient: Plants are in this range if it is doubtful that
further additions or reductions of the element will result in
a desirable increase of growth, yield, or quality.
Somewhere within this range is the absolute optimum,
which together with the combination of the other elements
present, will produce the most desirable production.
High: Plants are in this range if the level of the element
present in the plant is higher than necessary to produce op-
timum yield, growth or quality. This amount may indicate
unfavorable quality relationships or an imbalance of other
Excess: A plant contains an excess amount of an element if
visible leaf symptoms are present or definite reductions in
yield, vigor, or quality result.


General Use of Foliar Analysis
for Tropical and Subtropical Crops
My main goal today is to discuss the feasibility of using foliar
analysis to diagnose nutritional problems of tropical crops.
However, I have conducted only a minor portion of my research
under a tropical environment. Therefore, my knowledge of many
of your conditions is very limited. Hopefully, a discussion of
foliar analysis fundamentals, regardless of the crops used, will be
of value to you.
Extensive nutritional studies have been conducted on several
important tropical and subtropical crops such as bananas, pineap-
ple, citrus, oil palm and sugarcane. A review of the literature ap-
pears to indicate that foliar analysis data is available. However,
there are many additional horticultural crops of lesser importance
that have received only minor attention. Assuming that your in-
stitution wanted to set up a diagnostic service program as soon as
possible, how easy would it be to develop a database for some of
these crops? Personal experience, as well as a review of the
literature on foliar analysis, shows that at least two procedures can
be effectively used:
1. Conduct a routine foliar analysis survey of the crops under
2. Conduct some field experiments either concurrent with or
following the survey.
Through the first procedure, general levels can be established,
such as those presented in Table 1. If this information is combin-
ed with visual symptoms, growth ratings, quality evaluations and
indications of general plant condition, then much usable data can
be obtained quite rapidly. Some of the obvious errors created by
this procedure are that if soils do not provide an adequate cross-
section of nutritional conditions, i.e., mostly deficient or ex-
cessive amounts of certain elements (copper, boron, zinc, etc.)
are present, then adequate nutritional levels cannot be sampled.
However, in most areas there is an adequate range of condi-
tions, and foliar nutrient levels can readily be related to yield and
quality. Visual deficiency or excess symptoms can also help in-
dicate minimum levels.
Once approximate levels have been established by the survey
data, then field experiments should be conducted. Plantings
thought to be low or deficient in certain nutrients can be utilized
as effective experimental sites and corrective measures applied.
The results of your survey data can thus be verified and refined.
Without any previous history on a crop, what can be learned
from a foliar analysis? One of the very desirable associations that
can be used effectively is to compare plants growing in a satisfac-
tory vigorous condition with plants not growing well or those that
exhibit visual symptoms and those that do not. Some of the pit-
falls to be avoided here are: (1) do not take samples from ob-
viously diseased or physically injured plants; and (2) avoid plants
with known herbicide or chemical damage. Under either condi-
tion, nutrient concentrations will be obtained that are mean-
ingless because the primary cause of poor growth, etc., is not due
to nutrition, but to the injured or diseased condition. Drought,
salinity, poor drainage, and saturated soil conditions also offer
pitfalls that will lead to false interpretations of the foliar analysis
Thus, even though little or nothing is known about the re-
quired nutrient level of a crop, if comparisons are made using
healthy plants as your base, then some fundamental deductions
can be made. It has been the author's experience that within
reasonable limits somewhat typical levels of nitrogen,
phosphorus, potassium and other nutrients can be expected in
the average leaf or petiole of a plant (Table 1). There are notable
exceptions to this, but they become readily apparent with normal
sampling procedures for a given crop.

TABLE 1. Foliar nutrient levels associated with dry weight of some fruit crops.
--------------------------------------- -------------------ppn------------
Crop N P K Ca Mg Mn Fe B Cu Zn
Mango 1.4/2.0 .14/2.0 .7/1.1 1.8/2.6 .25/.35 30/150 70/120 35/100 5/15 25/50
(M. indica)
Guava 1.5/2.4 .15/3.0 .7/1.1 1.8/2.6 .25/.40 30/150 50/120 35/100 5/15 25/50
(P. guajava)
Litchi 1.9/2.6 .14/2.0 1.0/1.5 2.0/3.0 .30/.55 30/150 50/130 35/100 5/15 20/50
(L. chinensis)
Fig 1.8/2.0 .12/.18 1.0/1.5 3.0/5.5 .40/.70 25/50 50/120 35/100 5/15 25/50
Orange 2.0/2.6 .12/.18 1.2/1.7 3.0/5.5 .26/.60 25/50 50/120 35/100 5/10 25/50
Mandarin 2.8/3.0 .15/.26 .9/1.1 3.0/5.5 .26/.60 25/50 50/120 30/100 5/10 25/50
Grapefruit 1.5/2.2 .15/.26 .6/1.5 3.0/5.5 .26/.60 25/50 50/120 35/100 5/10 25/50

Three basic criteria should be combined when establishing a
foliar analysis procedure. They include: (1) a sample taken from a
leaf, petiole, or other easily identified tissue; (2) the position on
the plant should be equally easy to identify (first fully mature leaf
on current season's growth or mid-shoot leaf on the spring flush
of growth, etc.; (3) the tissue (leaf or petiole) should be in an 'ac-
tive' position on the plant (a leaf well exposed to ambient
sunlight on a fruiting shoot, etc.); (4) the time of sampling
should be a well-defined phenological period (mid-season or at a
specified number of days following bloom, veraison, etc.).

Relative Importance of Nutrient Elements
As a general rule the element of greatest concern in nutrition
studies is obviously nitrogen because it relates so strongly to yield
and quality. Most of our cultivated crops require additions of
nitrogen in one form or another in order to produce satisfactory
yield. Legumes are the major exception. The second element of
major concern would probably be potassium, especially in our
higher rainfall soils. Phosphorus, although very necessary for
plant growth, is generally not of major concern for fruit crops,
although for vegetables it frequently is in second position in
general fertilizer recommendations. Around the world, deficien-
cies or excesses of minor elements such as boron, zinc, and copper
play an important role in developing adequate yield and quality.

Development of a Grower Foliar Analysis Program
Ohio has had a grower service program since 1964. During this
period many thousands of samples have been sent to the
laboratory for analysis and the results returned to the growers
with recommendations. Some comments relating to this ex-
perience may be appropriate at this time.

Development of a Questionnaire. In most programs, the nutri-
tional specialist for a laboratory takes the sample, analyzes it and
completes the service by returning the information to the grower
with his recommendations. In Ohio, we have allowed the grower
to fill out a questionnaire (Fig. 1), take his own samples, and
send them to the laboratory.
With the development of computers, it seems as though much
of our information must be in abbreviated form. Thus, the use of
the information questionnaire, such as the one shown (Fig. 1),
has been reduced to the bare essentials. The original question-
naire developed for fruit crops in Ohio allowed the grower to in-
dicate conditions he saw in his plantings, but not interpret the
problem (nutritional or otherwise).
Kits are distributed to all county or district offices and depart-
ments. Only when the grower uses the kit and sends in the sam-
ple is he charged a fee. Thus, the kits are available in quantity at
a number of locations. Instructions for their use are attached. At
least 60 units (leaves, petioles, etc.) are requested per sample.
This is an attempt to make the grower get a good cross-sectional
sample of his planting. Turn-around time in the Ohio program
generally takes about 3-5 days. By the time the samples arrive on
my desk, five days have generally passed. For sample analyses on
which growers rapidly need the information, transmittal of
results may be by telephone. It must be recognized that in many



cases, especially for tree fruits, samples taken one year may not be
used until the appropriate season of the next year. However, with
increased speed of analysis the trend has been to get the informa-
tion back to the grower just as rapidly as possible, and then apply
the needed elements during the same season. This should be
even more important in the tropics than in temperate regions.
Standards for each crop are printed by the computer in the defi-
cient, low, sufficient, high and excess ranges previously indicated
(Fig. 2).
The importance of time of sampling, leaf age, and sampling
position must be continually emphasized to the grower. Three
basic criteria are frequently combined when establishing a
research or grower foliar analysis sampling procedure. They in-
clude: (1) a sample is taken from recent fully matured leaves (if
the petiole is used, it is from this type leaf); (2)the leaf should be
exposed to ambient sunlight conditions much of the time and
where applicable be on a fruiting shoot; (3) the time of sampling
should be about mid-season or a specified number of days follow-
ing bloom or another well-defined phenological period. The
research database developed for such crops is, therefore, tied to
these three conditions and all grower samples taken for this pur-
pose should conform to them.

Concurrent Research Programs
In the development of any foliar analysis service program a
concurrent research program is also extremely important. Many
problems as they are found in grower plantings, need to be incor-
porated into a research program for solutions. More problems
seem to be identified every year by the Ohio grower foliar analysis
program than can be resolved. Each year's results provides the
researcher with an updated survey as to nutritional conditions for
the crops sampled.
An applied nutritional research program can and must provide
the following information: (1) recommended nutrient ranges that
will reflect differences in growth, yield and product quality; (2)
effects of rates of fertilizer application for specific soil types, etc.
In this area, it is very necessary to conduct such experiments on
grower plantings in order to get reliable data; (3) a criterion for
proper sampling procedures that will most efficiently utilize the
database developed.
The use of a companion tool, soil analysis, has not been
discussed. It is well known that good soil testing methods are also
a desirable means of providing the grower with an additional tool
for his fertility program. For tree crops, it has been the general
feeling that foliar analysis provides a better indicator of what the
plant is actually absorbing than does soil analysis. However, in
the establishment of any crop, soil testing should be used before
planting or concurrent with foliar analysis where a problem is in-
volved. Basic modifications in the fertility and pH of the soil prior
to planting can then be made. In Ohio, a combined use of soil
and plant analysis has never been mandatory. However, we do of-
fer both programs. Independent analysis and recommendations

FIG. 2 The completed results form, with typical
recommendations, used by the Research Extension
Analytical Laboratory (REAL), Wooster, Ohio.

FIG. 1. Questionnaire used by the Ohio Research Extension Analytical Laboratory
(REAL), Wooster, Ohio.

rITUllRNllS I'III LLEANVEII LEMoltimA Hotoeura, Saops. No.
Ohio Cooperative Extension Service The Ohio State Univeity
and Ohio Agricultural Resarch and Development Center, Cooperating
Name: IGro,* Nam (If otnr mnte at lfJ):
Str t. RoutL: Coumty:
Citn: __ .Ohhio .nYLSmpleIdentification: i
Telehone Number:

L TYPE OF CROP: I(I Fra (2) Greonhao Va
. a CROP_

- PLANT APPEARANCE: (Checkl (1) Norn
(2) Abn<
D SOIL: (1) Fine or Medium Texture (clay an
pemt) (4) Container. Bed. Bench or I
average rainfall) (3) Normal (4) Low

OIL HI.TORYI Date Resovd
ibl 13(utedo Vtrables () Numrtry-Oad () Nuraw-Everrun I()Flonn
CULTIVAR (Variety)
(2) It Other. Describe

rl __ ,(Describe)
(0 to 99%)
d silt) (2) Coarse Texture (sandy) (3) Organic muck or
Pot Mixture
(1) Excessive (due to poor dninage) (2) High (due to above

PH O RATE: (1) Lbs/Acre (2) Lbs./Plant
LIME TEST INDEX (" 13) LbsJCu. Yd. (4) Ppm
SPhoshous Phosphorus (P2051
Potasium Potassium (K20)
Calcium Ag. Ground Limestone
SOIL TEST BY: 1. O.S.U., 2. Other Phosphorus (P2055
DATE TESTED: 19__ Potaosium (K 0)
SOIL TYPE (MAPPING) NUMBER j Ag. Ground Limestone

for both soil and plant analysis is not without its problems;
especially when a grower uses both and receives conflicting infor-
mation. For example: soil test indicates the potassium is low, but
the plant analysis indicates it is quite satisfactory (the amount
that is in the plant tissue must take precedence over the soil
levels, is a position I have always assumed). Discussions in grower
meetings, short courses, etc., have been necessary to help the
grower recognize that the best fertilizer program includes all the
information that he can get his hands on. This includes soil
testing, plant analysis, visual observations, previous experience,
the research information available on the crop involved, etc.
With the justification that they all offer some benefits, as well as
some sources for error, we will continue to study and develop
such methods to help the growers increase the quality and quan-
tity of their crops.

wOOST'!. O"'O Awl _
CtOwr10NO 1S02 K 00.84 XX X B 0020 XXXXXXXXXX
T SAH sO00S0 (I)Ca 01.32 XXXXXXXXXXXXX Cu 0010 txxxxxxxxxxXXXXX
DATtnEiNTo 07/25/80 11 s 0048


w RD 1
BOOSTER, OO10 44691
80 PCT.

P 12 Ibs/A 4S.0 0 0
K 169 Ibs/A LIHE O lbs.
OM 2 SALTS 24 S5.0 0 0
BY OSU LIME 0 lbs.
YEAR 1980


Adaptation of CIMMYT's High Protein

Quality Corn Varieties to Puerto Rico

C. Cardona L. Wessel-Beaver P. R. Hepperly
College of Agricultural Sciences
Mayaguez, Puerto Rico

Six modified endosperm opaque-2 corn varieties from
CIMMYT were evaluated at Lajas and Isabela, Puerto Rico in
1983. Two Puerto Rican varieites, Mayorbela and Diente de
Caballo, were used as checks. Opaque-2 (o2) corn normally
has soft endospoerms, while modified varieties approach the
appearance of normal corn. The subplots of each variety were a
check, benomyl treatment, and Fusarium moniliforme silk in-
oculation. Traits measured included incidence of seedborne
fungi, plant and ear heights, visual ear infection, ear lengths
and diameter, yield and 500 kernel weight, and modification.
Yields and modification of the CIMMYT varieties were similar

to that of the traditional (non o2) varieties. F. moniliforme
was found to be the most important seedborne fungus. The
inoculation technique was found to increase incidence of F.
monoliforme and should be useful for evaluating large
numbers of families in a selection program. Improvement of
yield and adaptability of CIMMYT's materials is needed for
viable commercial production of these varieties. On the basis
of this evaluation, S1 recurrent selection has begun in two
modified o2 varieties.
Keywords: Zea mays L., maize, opaque-2, modified
opaque-2, Fusarium monoliforme.

Since the discovery of opaque-2 (o2) endosperm mutant by
Mertz et al. (1964), many directions of research have been tried in
order to efficiently utilize the gene's ability to increase lysine and
tryptophan levels, thus improving corn protein quality. Early on,
some researchers were discouraged by undesirable characteristics
such as lower grain yield, poor consumer acceptance, and suscep-
tibility to machine harvest damage, insects and ear rots (Diaz,
1972; Gulya et al., 1979; Lambert et al., 1969; Pinstrup-
Anderson, 1971; and Warren, 1978). Since the 1970's much work
has been directed towards the use of genetic modifiers that improve
the endosperm texture of o2 corn, giving it a more normal ap-
pearance and hardness. CIMMYT (Centro Internacional de Mejora-
miento de Maiz y Trigo) has used this approach to develop its
"quality protein maize" (QPM) populations (Vasal et al., 1980).
Although once a widely grown crop, very little corn is presently
grown in Puerto Rico. Nevertheless, large quantities of corn are
imported as feed for the livestock, pork, and poultry industries
(Puerto Rico Department of Agriculture, 1979-80). Furthermore,
as fewer acres are planted to sugarcane, alternate crops and rota-
tions of crops must be considered. Local production of corn
varieties with improved protein quality could reduce the amount
of corn and protein supplements that are presently imported for
monogastric animals such as swine and poultry.
The primary objective of this research was to compare the
adaptation of six modified endosperm o2 corn varieties to two
traditional varieties in Puerto Rico. Other objectives were to:
1. Determine the susceptibility of modified o2 and tradi-
tional varieties to ear infection by Fusarium moniliforme,
comparing natural and artificial inoculation;
2. Select the best modified o2 varieties for use in a S1 family
recurrent selection program; and
3. Determine which agronomic characteristics should be in-
cluded in a selection program.

Six modified (hard and vitreous) endosperm o2 corn varieties
from CIMMYT, and two Puerto Rican varieties (Mayorbela and
Diente de Caballo) were evaluated in trials planted in March and
May 1983, in Lajas and Isabela, Puerto Rico, respectively. Diente
de Caballo is a tall, late, floury type, while Mayorbela is earlier
and shorter with a flint kernel type. A split plot design, with


eight varieties arranged in a randomized complete block design
and three subtreatments, was used. The subplots were:
1. A check not sprayed or inoculated;
2. A treatment with the fungicide Benomyl, but
uninoculated; and
3. Artificial inoculation with Fusarium moniliforme.
The whole plots were randomized except for the normal varieties
which were either placed downwind from 02 varieties and/or
were surrounded by an o2 bulk to minimize normal contamina-
tion of the o2 varieties.
The twelve row whole plots were divided into four rows per
subplot. Row length was 5.1 m with plants spaced 26 cm apart
(about 43,200 plants per hectare). Fertilizer was preplant incor-
porated at a rate of 56 kg ha-' of 15-5-10 with 175 kg ha-' of
nitrogen sidedressed at five weeks after planting in the form of
urea. Furadan (1.7 kg ha-' of actual ingredient) was preplant in-
corporated and insecticides (Lannate and Sevin) applied weekly
or biweekly as needed. Trials were irrigated as needed. Lasso and
Round-up were used for weed control. The center two rows (ex-
cluding end plants) in each subplot were hand harvested.
At Lajas, the fungicide Benomyl was sprayed on the ears and
silks when the first varieties began to flower and ten days later. At
Isabela one application of Benomyl was used at ten days after first
flowering (when all varieties were flowering). Inoculation of F.
moniliforme was carried out by a modification of a technique us-
ed by Warren (1978). A suspension of spores was brushed onto
silks cut with a scissors to a length of about 2.5 cm. The silks were
then covered with a pollination shoot bag. In Lajas a total of 20
plants in two rows were inoculated at 10 and 20 days after first
flowering (the average of the two dates is used in this report). In
Isabela only one inoculation was made.
Traits measured were days to 50% anthesis, plant and ear
height, ear length and diameter, number of moldy kernels, per-
cent of ear area damaged by insects (primarily ear worm), grain
yield, 500 kernel weight, percent endosperm modification,
degree of endosperm modification (reference 10 with technique
modified to a 0 to 5, opaque to normal, scale), percent germina-
tion and seedborne fungi.
Data were subjected to analyses of variance separately and over
locations. Treatment means were compared using a protected
LSD (F-LSD) (Carmer and Swanson, 1971).


Significant differences due to location were found for most
traits except for 500 kernel weight and modification (not shown)
(Table 1). Isabela was the more productive environment.
Very few differences among varieties were found (Tables 2 and
3). Number of moldy kernels varied significantly among varieties
with White H.E. o2 being most susceptible to infection and local
variety Diente de Caballo the least susceptible. Although the
Puerto Rican varieties were less ear rot susceptible and taller than
modified o2 varieties, in general the modified varieties per-
formed well. Percent and degree of modification did not vary
among varieties, with all varieties showing excellent levels of
edosperm modification (Table 3). It appears that the o2 modifiers
are relatively stable over different environments. Our results show

Table 1: Location means of agronomic traits averaged over seven corn
varieties planted in March (Lajas) and May (Isabela), 1983.

Trait Lajas Isabela X LSD
Earworm (percent of
ear damaged)1 6.3 0.1 3.2 0.99
No. of moldy kernels
per ear1 3.8 8.3 6.1 1.12
Plant height (cm) 150 189 170 6..54
Ear height (cm) 67 83 75 3.09
Ear length (cm)1 12.6 14.1 13.3 .54
Ear diameter (cm)1 4.2 5.1 4.6 0.55
Days to 50% anthesis 61 55 57.6 1.03
Yield (kg ha-1)2 3054 3888 3472 427.6
500 kernel weight (g)1 122.6 132.9 126.9 4.65 (n.s.)
1Averaged over all subplot treatments.
2Averaged over check and benomyl treated subplots.
n.s. = No significant differences among locations according to F-test.
LSD = Least significant difference at 0( = 0.05.

Table 2: Means of various agronomic traits over two
varieties *


Diente de caballo2


White HE-o2

Amarillo Dentado

Tuxpefo-1 QPM


Amarillo Dentado QPM

Amarillo Cristalino QPM

that those varieties with a high percent modification also have in-
dividual kernels with a high degree of modification. It will not be
necessary to select directly for endosperm modification in a selec-
tion program aimed at improving adaptation of these materials in
Puerto Rico. Very poorly modified families should nevertheless
be eliminated in a selection program.
No variety by location (i.e., genotype by environment) interac-
tions were found for any trait (not shown). This means that
varieties responded similarly at both locations for all traits
although location means were often different. This would nor-
mally suggest that testing at one location would be sufficient
when testing these traits and varieties. However, lack of a variety
by location interaction may be due in part to lack of sufficient
precision in determining possible differences between varieties.

Table 3: Percent and degree of endosperm modification in two normal and
six modified c2 corn varieties averaged over two locations 1

Variety Percent Modification Degree of Modification3
Diente de Caballo2 96.7 3.7a
Mayorbela 100 5.0
White H.E. 02 95.8 4.1
Amarillo Dentado 99.5 3.9
Tuxpefo-1 QPM 98.1 4.0
Pool 23 99.4 4.1
Amarillo Dentado QPM 98.4 4.0
Amarillo Cristalino 100 4.2
Mean 98.7 4.2

iValues are means over two locations (Lajas and Isabela) and three subplot
2Mean over three treatments at Lajas only.
3Ratings from 0 to 5 (opaque to normal).

locations for six modified o2 and two normal corn

Moldy Insect Days to Plant Ear Ear Ear Grain kernel
;ernels damage 50% height height length diameter yield weight
(no.) (%) anthesis (cm) (cm) (cm) (cm) (kg/ha) (g)

2.4 6.1 64 194 100 13.3 4.6 3030 172.3

4.6 3.5 56 182 91 14.4 3.9 3963 137.6

10.5 3.5 59 177 79 14.3 5.3 3652 124.9

5.2 2.9 58 173 76 13.4 4.9 3583 125.7

6.9 3.0 58 158 64 13.2 4.6 3372 130.6

4.8 2.5 58 165 71 12.9 4.8 3139 122.6

3.5 2.8 58 165 70 12.4 4.7 3378 125.3

7.0 4.1 57 168 71 12.8 4.3 3215 121.7

X 6.1 3.2 58 170 75 13.3 4.6 3472 126.9

LSD 1.8 2.1 1.9 12.2 4.5 .98 1.0 800.0 8.7
(n.s.) (n.s.) (n.s.) (n.s.)

Values are means from Lajas and Isabela, Puerto Rico with the exception of Diente de Caballo. Averaged
over subplots as indicated in Table 1.
Mean from Lajas only. These menias are not included in the overall mean.
n.s. = No significant differences among varieties according to F-test.
LSD = Least significant difference at rd = 0.05.




Artificial inoculation with F. monliforme was successful in in-
creasing number of moldy kernels and incidence of seedborne F.
moniliforme compared to the check (natural inoculation) (Table
4). Visual infection can perhaps be increased by increasing the
number of inoculations, thus making this technique even more
useful for selection purposes. The fungicide Benomyl was not ef-
fective in reducing visual nor seedborne F. moniliforme com-
pared to the check, nor did it significantly increase grain yield
(Table 4).
Table 5 shows that F. moniliforme was the most important
seedborne fungus both in Isabela and Lajas. Incidence of most
seedborne fungi was greater in Lajas. Conditions in Isabela were
very dry in the 1983 growing season.
Significant subplot treatment by location interactions were
found for moldy kernels, earworm damage, ear diameter, and

grain yield (Table 6). Earworm damage was virtually nonexistent
for all subplot treatments in Isabela, while there were significant
differences among treatments at Lajas. In the combined analysis
(Table 4) no differences among subtreatments were found. The
artificial inoculation technique was much more effective in
Isabela even though only one application was used, thus causing
a significant interaction. Grain yields were not different among
treatments at Lajas but varied sharply in Isabela. The reason for
this interaction of treatment and location is not understood.
Based on the results of these trials two modified o2 varieties,
Amarillo Cristalino QPM and Tuxpefio-1 QPM, have been
chosen to undergo S1 family recurrent selection. Grain yield, ear-
ly maturity and plant height will be used in an independent cull-
ing levels selection scheme. Poorly modified families will be

Table 4: Means of subplot treatments averaged over seven corn varieties planted at two locations in
March (Lajas) and May (Isabela), 1983.


No. of moldy kernels

Earworm (% of ear

Ear length (cm)

Ear diameter (cm)

Grain yield (kg ha

Fusarium moniliforme
(number of colonies
per 50 seed)

(without fungicide)
without inoculation)







Benomyl treated
(without inoculation)







(without Benomyl)














.35 (n.s.)

4.6 0.65

3510 272.9 (n.s.)



Only traits exhibiting significant differences among treatments are included, except for grain

LSD = Least significant difference at = 0.05.

N/A = Treatment not included.

Table 5: Location means for seedborne fungi and percent germination averaged
over all varieties.

Lajas Isabela X LSD
Fusarium moniliforme 58.6 22.8 40.7 5.27
Penicillium spp.
(green type) 22.5 18.8 20.6 7.6 (n.s.)
Penicillium spp.
(yellow type) 8.8 6.0 7.4 3.06 (n.s.)
Aspergillus spp. 11.1 6.4 8.8 2.94
Trichoderma spp. 7.6 3.0 5.3 5.6 (n.s.)
theobromae 0.9 2.0 1.4 0.79
Total 123.4 97.5 110.4 33.4 (n.s.)
% Germination2 68.2 93.9 81.1 4.5

1Table includes only those fungi found at both locations. Means are
average number of colonies per 50 seeds, over three subtreatments.
2Percent germination in laboratory.
LSD = Least significant difference at Q = 0.05.
n.s. = No significant differences among locations.


Table 6: Location means for traits showing significant subplot treatment by
location interaction.

No. of Ear Grain
Earworm moldy diameter yield
Treatment Location Damage (%) kernels (cm) (kg ha-1)

'Check Lajas 5.7 3.5 4.2 3147
Isabela 0.1 6.9 4.4 272?
Benomyl Lajas 9.1 2.8 4.2 3097
Isabela 0.1 6.0 5.1 3971
Inoculation Lajas 4.0 4.6 4.2 N/A
Isabela 0.1 12.6 5.8 N/A

N/A = Not applicable


The authors wish to thank Mrs. Carmen Teresa Ramlrez and Miss Luz
Gonzilez for their technical help.

1. Carmer, S.G., and M.R. Swanson. 1971. Detection of differences between
means: A Monte Carlo study of five pair wise multiple comparison procedures.
Agron. J. 63:940-945.
2. Diaz Castro, G. 1972. The importance of the husk and the opaque-2 gene
in studies of insects in stored grain. (In Spanish). Agric. Tec. Mex. 3:153-156.
3. Gulya, TJ., C.A. Martinson, and L.H. Tiffany. 1979. Ear-rotting fungi
associated with opaque-2 maize. Plant Dis. Rept. 63:370-373.
4. Lambert, RJ., D.E. Alexander, andJ.W. Dudley. 1969. Relative perform-
ance of normal and modified protein (opaque-2) maize hybrids. Crop. Sci.

5. Mertz, E.T., L.S. Bates, and O.E. Nelson. 1964. Mutant gene that changes
protein composition and increases lysine content of maize endosperm. Science.
6. Pinstrup-Anderson, P. 1971. The feasibility of introducing opaque-2 maize
for human consumption. Technical Bulletin, CIAT, No.1.
7. Puerto Rico Department of Agriculture. 1979-80. Facts and figures in Puer-
to Rico's agriculture. pp. 8, 28, 32 and 79.
8. Vasal, S.K., E. Villegas, M. Bjarnason, B. Gelau, and P. Goertz. 1980.
Genetic modifiers and breeding strategies in developing hard endosperm opaque-2
materials, in: Improvement of quality traits of maize for grain and silage use, (Eds.
W.G. Pollmer and P.H. Phipps). The Hague, The Netherlands: Martinus Nijhoff
Publ., pp. 37-73.
9. Warren, H.L. 1978. Comparison of normal and high lysine inbreds for
resistance to kernel rot caused by Fusarium moniliforme. Phytopathology.
10. Wessel-Beaver, L. and R.J. Lambert. 1982. Genetic control of modified en-
dosperm texture in opaque-2 maize. Crop. Sci. 22:1095-1098.



Some Factors Affecting the Adoption of Hand Tractors

by Vegetable Farmers in Trinidad
Based on post graduate research carried out in the Department of Agricultural Extension,
Faculty of Agriculture, The University of the West Indies, Trinidad and Tobago,
by the senior author.

William G. Clarke
Agriculture Department, Geo. F. Huggins & Co. Ltd.
Port of Spain, Trinidad

There is scope for reducing the level of labour required by
vegetable farmers by use of small machines. Thirty-five
farmers from the main vegetable growing area who purchased
hand tractors were interviewed along with 35 farmers who did
not purchase and who were matched with the purchasers for
location of farm, ethnic background and age. A 34-question
interview schedule covered farm-related, innovation-related,

P. I. Gomes
Department of Agricultural Extension
The University of the West Indies
St. Augustine, Trinidad

personal and social variables. Agricultural training, source of
information, size of farm, tenure and relative advantage were
positively related to adoption of hand tractors. The high cost
and scarcity of labour was not a factor affecting adoption
Keywords: Adoption; hand tractor; market gardening

Trinidad and Tobago, like many countries in the Caribbean, is
attempting to come to terms with a high and rising food import
bill accompanied by declining agricultural production. The wind-
fall profits of oil provided the foreign exchange to pay for the ris-
ing expectations of a population enjoying an increased standard
of living and suffering from the consequent inflation..
The oil industry and other non-agricultural sectors of the
economy were able to support the level of wages that the
agricultural sector could not afford and therefore could not ob-
tain. At the same time farmers also expected the level of financial
return that was necessary for them to keep pace with fast rising
prices and to participate in the improved standard of living in the
economy of which they are a part. This was especially critical in
farming areas within proximity of urban communities. Vegetable
farming in County St. George, Trinidad, is one such area where
vegetable farmers reside and cultivate their crops close to the
capital city Port of Spain, their principal market.
The Ministry of Agriculture has identified the high cost and
scarcity of labour as a constraint to agricultural production
(Ministry of Agriculture, 1979). In the case of County St. George,
what appeared to be the obvious solution to the farm labour
problem was the mechanization of small vegetable plots that are
traditionally cultivated under a labour intensive system.
The single axle or hand tractor, also described as a "walking"
tractor or power tiller, was considered to be the answer to the
problems of mechanization of small vegetable plots (Carr, 1970;
Harvey, 1983).
The hand tractor has emerged as being best for rotavating
which confines its use to situations where primary tillage is not re-
quired or can be provided by a large tractor. When compared
with the capital outlay for a large tractor, ownership of a hand
tractor is within closer reach of a small farmer. The timing of
operations in vegetable production is critical, especially under
rain fed conditions. Ownership of a hand tractor would give
farmers some control over their operations and allow them to take
advantage of short periods of favourable weather. McMillan
(1967) reported that hand tractors were demonstrated to farmers
in the Aranguez area, the principal market gardening district in
County St. George, Trinidad, since 1966.


The availability of hand tractors and exposure of these
machines to vegetable farmers have not led to their widespread
adoption. This study sets out to identify some of the factors
which are related to the adoption use of the hand tractor in
County St. George.

Materials and Methods
County St. George is one of seven counties in the island of
Trinidad. In work done by Ali et al. (1973), County St. George
was described as the largest vegetable producing area in the coun-
try. At the end of 1980, there were 1,143 registered farmers. Over
70 percent of these farmers depended on agriculture as their only
source of income. The data shows that 67.1% of the farming
population was 40 years old and above. The average farm size was
about 1 ha. This was due to the fact that most farming operations
were performed manually, limiting the size of plot to that which
one family can effectively cultivate. Primary and secondary tillage
are carried out by large tractors on a contract basis.
The present study covered the period January 1977 to
December 1980. Two models of hand tractors were available on
the local market; the 3.73 kW Wolseley and the 5.97 kW Grave-
ly. The period chosen was influenced by the availability of data
from the firms marketing these units and the limitation of time
and other resources.
Commercial vegetable production in County St. George is
generally confined to the River Estate Soil Series on which 89% of
the vegetable farmers are located. In this study, the population of
vegetable farmers was stratified on this soil type.
A list of the purchasers of hand tractors who farmed on this soil
type was compiled using the names and addresses obtained from
the firms marketing the hand tractors. Each purchaser was matched
with a non-purchaser on the basis of location of farm, ethnic
background and age, resulting in a sample size of seventy farmers.

Note: Mention of a tradename in this paper does not constitute an endorsement of
the product over other products not mentioned.
See Appendix.

TABLE 1. Adoption category by level of agricultural training received.

Adoption Level of Agricultural Training Received
Adoption---- -- ---- -- ---
Category None Other Field School Total
Days Garden

Adopters 19 1 3 12 35
Non-Adopters 26 2 5 2 35

T o t a 1 45 3 8 14 70

X2 (0.05) = 12.06 Three (3) degrees of freedom
Probability at the .001 level

The innovation to be adopted was the hand tractor. The
dependent variable was the adoption of the hand tractor by
vegetable farmers. The indicators used to measure this variable
were as follows:
Adopters: those farmers who had purchased the hand trac-
Non-Adopters: those farmers who had not purchased the
hand tractor.
The independent variables were treated as follows:

Personal and social variables
1. Age: Was used to identify any possible trends in the
population and to match non-adopters with adopters.
2. Ethnic background: This was also used for identification
and compilation of the sample.
3. Level offormal education: Attendance at any institution
of learning ranging from primary to tertiary.
4. Level of agricultural training: Exposure to information
and techniques specifically related to agriculture.
5. Size of household: Taken to be the nuclear family unit.
The following categories were use: Small--2 persons and
less; Medium- 3 to 5 persons; and Large 6 and more per-
6. Attachment to agricultural organizations: Whether a
farmer is a member of an organized farmers' group and at-
tendance at meetings were determined.
7. Source of information: Refers to the number of contacts
by which a farmer obtained his initial exposure to the in-

Farm related variables
1. Farm size: The number of hectares cultivated by the
farmer on a regular basis. The following categories were
used: Small-less than 1 ha; Medium-1 to 2.2 ha; and
Large-more than 2.2 ha.
2. Tenure: Security of tenure was classified into five
categories: family land, rental, leasehold ownership,
freehold ownership, and other.
3. Praedial larceny: Respondents' perception of the level of
loss from their farms.
4. Home to farm distance: This variable was also used in mat-
ching respondents for the sample.
5. Time spent in farming: The respondent's perception of
the proportion of the day actually spent on the farm.
6. Use of Family Labour: This was taken as an indication of
the amount of manual labour available to the farmer.
7. Use ofHiredLabour: This factor was used to determine the
extent to which farmers utilized hired labour. Two or less
man days per week was classified as low. More than 4 man
days per week was regarded as high.

TABLE 2. Adoption category by number of contacts used as source of information.

Adoption Number of Contacts
Category One Two Three Four & Total

Adopters 2 8 22 3 35
Non-Adopters 4 16 12 3 35

To t a 1 6 24 34 6 70

X2 (0.05) = 13.2 Three (3) degrees of freedom
Probability at the .01 level

Innovation related variables
1. Custom use of large tractor: It was assumed that the level
of acceptance of the hand tractor was affected by the extent
to which farming operations were hired out to large trac-
2. Relative advantage of the innovation: The following four
sub-dimensions of relative advantage were measured by
the perception of respondents: saving of time and effort;
low initial cost; lower perceived risk; and degree of
economic profitability.
A 34-question interview schedule was designed to obtain infor-
mation covering the independent variables listed above. Data
giving other characteristics of the population were also included.
Use was made of fixed alternative and open ended questions. Per-
sonal questions were placed towards the end of the interview
schedule in order to minimize the amount of information that
would be lost should the interview be terminated as a result of
these questions.
Based on a literature review and the theoretical framework, the
following hypotheses were proposed for testing:
The adoption of hand tractors by vegetable farmers is positively
related to:
1. level of formal education of adopters;
2. level of agricultural training of adopters;
3. level of attachment to agricultural organization;
4. land tenure of adopters;
5. time spent in farming as perceived by adopters;
6. level of use of family labour as perceived by adopters; and
7. the following subdimensions of relative advantage of the
innovation as perceived by adopters: a saving of time and
effort; low initial cost; lower risk; and degree of economic
The adoption of hand tractors by vegetable farmers is negatively
related to:
1. size of household of adopters;
2. farm size of adopters;
3. level of praedial larceny from the farm; and
4. custom use of large tractors.
The adoption of hand tractors by vegetable farmers is related to:
1. the source of information of adopters; and
2. the level of utilisation of hired labour by adopters.
The hypotheses were tested by the chi square test which was
used to examine the relationships between different factors.

Results and Discussion
The respondents ranged in age from 27 to 56 years old and
74.3% of the respondents were 40 years old and above. Sixty-
nine respondents (98.6%) were of East Indian descent. Since
these two variables were used to classify the respondents no con-
clusion with regards to adoption can be made.



TABLE 3. Adoption category by size of farm.

Adoption Category Farm Size
Small Medium Large Total

Adopters 5 22 8 35
Non-Adopters 22 11 2 35

T o t a l 27 33 10 70

X2 (0.05) = 17.96 two (2) degrees of freedom
Probability at the .001 level.

The following characteristics of the population were obtained
from the study. Of the respondents, 22.8% had no formal educa-
tion, therefore the adoption behaviour of these farmers may not
be influenced by written material about the innovation. The
percentage of adopters who did not receive any formal education
is 14.3% as compared with 31.4% of the non-adopters, giving a
positive relationship between formal education and adoption
which was not significant. On the other hand, 45.8% of the
adopters received some agricultural training compared with
25.7% of the non-adopters, showing a positive relationship be-
tween agricultural training and adoption (Table 1). This was
found to be very significant when the hypothesis was tested.
It was found that more adopters had small households while
there were more non-adopters with medium and large house-
holds, indicating that non-adopters had a larger source of family
labour for manual farm work.
More non-adopters (62.9%) were attached to agricultural
organizations than adopters (51.4%). It was also found that more
non-adopters attended meetings than adopters. This negative
relationship may indicate that the organizations were not in-
volved with matters of interest to adopters.
The principal source of information of the hand tractor was
another farmer: 91.4% of the respondents first saw the hand trac-
tor at another farm and 62.9% first heard of the hand tractor
from another farmer. This seems to indicate the level of credibili-
ty and/or the level of farmer contact with extension and other
personnel. Three and more contacts were used as sources of infor-
mation by 71.5 % of the adopters and 57.1% of the non-adopters
(Table 2). A positive and significant relationship was found be-
tween number of contacts used as a source of information and
The mean farm size was 1.6 ha. The modal size of adopters'
farms was 2 ha, while the modal size of non-adopter's farms was
0.8 ha. Small farms were cultivated by 62.9% of the non-
adopters and 14.3% of the adopters (Table 3). The positive rela-
tionship between farm size and adoption may be due to the fact
that non-adopters could not afford to purchase hand tractors
because of the lower scale of return from their smaller size plots.
There was a very significant and positive relationship between
farm size and adoption.
There was a uniform distribution between adopters and non-
adopters in the categories of leasehold and freehold tenure. More
adopters than non-adopters rented farm plots and more non-
adopters farmed family land. No clear relationship between type
of tenure and adoption was indicated.
A low level of praedial larceny was reported by 71.4% of the
respondents based on their perception of level of loss. There was
no observable difference between the level of loss reported by
adopters and that by non-adopters.
None of the respondents lived on their farms. This variable was
used to match adopters and non-adopters, therefore no relation-
ship with adoption behaviour was established.


TABLE 4. Adoption category by type of tenure of farmland occupied.

Adoption Category Type of Tenure
Family Rental Long Term Total

Adopters 1 28 6 35
Non-Adopters 8 22 5 35

T o t a 1 9 50 11 70

X2 (0.05) 15.12 two (2) degrees of freedom
Probability at the .001 level.

Ninety percent of the respondents spent all of their time farm-
ing. This is in keeping with the background study that over 70%
of these farmers depended on agriculture as their sole source of
income. There was no observable difference between the time
spent farming by adopters and non-adopters.

More adopters assessed their use of family labour as low, in
keeping with information above that adopters had small house-
holds. This gives a negative relationship between use of family
labour and adoption. More adopters also used a higher level of
hired labour than did non-adopters, possibly because of their
lower utilisation of family labour and cultivation of larger plots as
mentioned above.
All respondents hired large tractors for weeding before tillage,
ploughing and rotavating. There is an apparent inconsistency in
that 100% of the adopters use large tractors for rotavating and at
the same time own hand tractors which are primarily used for
rotavating. Farmers explained that the large tractor is not used for
every crop but at 2-4 year intervals when the soil becomes dif-
ficult for the hand tractor. In St. Vincent where the Gravely hand
tractor was used for rotavating, it was reported that ploughing
was necessary when the soil became compacted (Anonymous,
1981). Harvey (1983) also found that these machines have their
greatest potential in situations where no primary tillage was

All adopters reported that one reason for purchasing the hand
tractor was the time they expected to save in carrying out opera-
tions, 82.8% regarded the saving of effort as their reason and
91.4% wanted to increase their income. Only 2.9% of the
adopters saw the unavailability of labour as their reason for pur-
chasing the hand tractor.
One reason given by 72.3% of the non-adopters for not pur-
chasing the hand tractor was the price. On the other hand, 60%
of the adopters regarded the purchase of the hand tractor as a
sure investment and 91.4% thought that they increased their
profit since using the hand tractor.
Rotavating was the main operation for which 100% of the
adopters used the hand tractor. This was also the main operation
that 97.1% of the non-adopters thought could be carried out
with the machine. No adopter used the hand tractor for
ploughing, although the ploughing attachment for the machine
could have been purchased on the local market. This observation
is in keeping with the view that the machine is unsuitable for
primary tillage operations (Harvey, 1983).
There was acceptance of the hand tractor by all adopters for
banking (formation of ridges and furrows). Most adopters
(97.1%) also used the machine for inter-row weeding. Some
measure of inter-row cultivation is achieved during inter-row
weeding. Some measure of inter-row cultivation is achieved dur-
ing inter-row weeding.


On testing the hypotheses presented above, the following fac-
tors were found to be positively related to the adoption of hand
1. Level of agricultural training;
2. Number of contacts used as a source of information;
3. Size of farm;
4. Type of tenure of farmland occupied; and
5. The following subdimensions of relative advantage of the
a. saving of time and effort;
b. lower perceived risk; and
c. degree of economic profitability.
The following factors did not influence the adoption of hand
1. Size of household;
2. Attachment to agricultural organizations;

3. Praedial larceny;
4. Time spent in farming;
5. Use of family labour;
6. Use of hired labour;
7. Custom use of large tractor; and
8. The relative advantage of low initial cost of the hand tractor.

The study has shown that the hand tractor can be an acceptable
means of mechanizing small vegetable farms within the limita-
tions of its suitability to some farm operations. It is important to
note that the study did not find the high cost and scarcity of
labour as a factor influencing the adoption of the hand tractor.
This could be explained by the fact that family labour was able to
cope with the labour requirements of small farms studied.
The rate of adoption of the innovation was not included in this
study because of the lack of individual farm records. Future work
should be done while an innovation is being adopted.

The authors thank the participating farmers for their cooperation; Drs. R.A.I.
Brathwaite, W. Harvey and Messrs. I. Bekele and S. Harryram for technical
assistance; Miss J. Marine and Miss A. Veira for assistance in preparation of the
script; and the staff and management of Geo. F. Huggins & Co. Ltd., who made the
presentation of this paper possible. Special gratitude is hereby expressed to Professor
T.H. Henderson who inspired and guided this research work.

1. Ali, R., V. Thomasos, K. Morton-Gittens, W. Augustin-Coryat, K. Beckles,
and G. Bally. 1973. Land capability studies, Phase II, Trinidad and Tobago Report
No. 3--Agriculture in County St. George, Ministry of Planning and Development,
Government of Trinidad and Tobago. p. 5.
2. Anonymous. 1981. Walking tractors in St. Vincent, CARDI Courier 1(2):2
Caribbean Agricultural Research and Development Institute, Information Unit,
3. Carr, T.W.A. 1970. Engineering application in horticulture. First Intera-
tional Seminar on Agricultural Engineering, U.W.I. St. Augustine. p. 241.
4. Harvey, W. O'N. 1983. Mechanization for improved crop production.
Paper presented at Agro-Tech '83. New technologies in food production for the
eighties and beyond. U.W.I. Faculty of Agriculture, St. Augustine, Trinidad and
Tobago, June 26-30, 1983.
5. Ministry of Agriculture, Lands & Fisheries, Republic of Trinidad and
Tobago. 1979. White paper on agriculture 1978. Government Printery, Trinidad
and Tobago. 96 pp.
6. McMillan, A.A. 1967. The development of market gardening in Aranguez,
Trinidad. Unpublished Ph.D. thesis. U.W.I. Library. p. 361.


Prices of selected tractors and attachments on the local market at December 1980.
Make Power (kW) Attachments Price

Wolseley 3.73 Unit with rotors $ 2,335.60
Brushcutter 837.50
Sicklemower 1,725.75
Furrower 89.46
Roadwheels 542.20

Graveley 5.97 Unit with roadwheels 4,105.00
Brushcutter 1,200.00
Sicklemower 1,400.00
Rotavator 1,300.00
Plough 1,600.00
Cart 1,000.00
Ride on Seat 1,000.00
Planting Drill 475.00

Ford 35.06 Unit 26,577.00
Brushcutter 3,2257.00
Rotavator 4,220.79
Discplough 4,395.00

John Deere 39.54 Unit 28,500.00
Brushcutter 3,825.00
Discplough 4,400.00
Rotavator 8,100.00


Jojoba-An Alternative Agriculture

in the Caribbean Area

Ralph C. Cutting, Jr.
R.C. Cutting & Co.
P.O. Box 273, Belmont, MA 02178

The need for a substitute for sperm whale oil and for a
lubricant to replace depleting fossil fuel reserves has been a
strong incentive for the development of jojoba, a plant native
to the southwestern U.S. and northern Mexico. Its popularity
now is based upon its ability to grow in soils of marginal fer-
tility, needs little water, withstands salinity and seems not to
need fertilizers and chemical treatments. Jojoba can be grown,
but can we afford to produce a crop? How much will it cost to
produce? What will it yield? What will it sell for once produc-
tion increases? These are major questions. Continuing research
is needed to determine optimum plant spacing, male-to-

female ratios, fertilization, weed-disease-insect control, culti-
vation and harvesting techniques. Answers to these questions
take time and continuing genetic breeding must be done
before consistently high yielding can be expected. The cost of
producing jojoba appears to be economically feasible now,
based upon existing knowledge. Plantations now-need to be
developed on large enough scales to demonstrate jojoba grow-
ing feasibility. This system will provide a basis for establishing
this industry in the Caribbean when the need for raw materials
becomes acute.

JOJOBA: What is it?
A 45-ton 75-foot long sperm whale and a desert bush share a
natural miracle: both produce highly prized unsaturated oils that
have a multitude of industrial and consumer product uses. But
because the hunted leviathan is an endangered species, its oil
cannot be imported into the United States. Actually jojoba is a
better natural substitute. An acre of jojoba could replace the oil
taken from 30 sperm whales.
Jojoba (pronounced ho'ho'ba) is a shrub of the Sonoran
Desert that has recently received widespread attention. Its
almond-shaped seeds contain an oil for which many uses have
been suggested. Much of the popular attention jojoba has re-
ceived is due to the fact that jojoba can be substituted for sperm
whale oil.
An important industry based on utilization of jojoba is now
present in the southwestern U.S., Mexico and Israel. New ex-
perimental plantations exist in Brazil, Argentina, Spain, India,
Paraguay, Chile, West Australia, Italy and Sudan. Two factors
point optimistically toward a successful jojoba industry:
1. Extensive stands of jojoba exist throughout the southwest-
ern U.S. and northern Mexico in numerous suitable loca-
tions with a minimum of irrigation.
2. A wealth of scientific literature and laboratory tests indicate
considerable potential for a variety of jojoba products.

General Information
The native habitat of jojoba is in the Sonoran Desert of
Arizona, California, and Mexico covering 100,000 square miles
between latitudes 25 degrees and 31 degrees North. Extended,
this area would be in the Bahamas and Southern Florida. There
are many populations varying from a few individuals to several
hundred per acre, and some populations where millions of in-
dividual plants occur. In the Sonoran Desert this dioecious (male
and female flowers occur on separate plants) evergreen shrub
generally occupies elevations between 2,000 and 4,000 feet.
However, in Baja, California and some locations in Sonora it oc-
curs at sea level. Rainfall throughout its range is 5" to 18" annual-
ly. Temperatures range from highs of 115"F. to lows of 15 F.,
but seedlings are sensitive to frosts. Jojoba is considered an im-
portant year-round forage plant for many desert animals. It is also
excellent browse for game and livestock, and the seeds are util-
ized by birds and rodents. However, seed meal is highly toxic to
humans and most animals unless detoxified.


Potential Uses
The oil is actually a liquid wax made of straight-chain acids and
alcohols that are difficult and expensive to artificially produce.
Small manufacturers are using all they can lay their hands on to
produce high-priced cosmetics like moisturizers, conditioners,
shampoos, sun screens, and after-shave lotion.
In its solid state, jojoba oil can be a cheaper replacement for
carnauba wax, beeswax, and other plant-derived waxes now sell-
ing for up to $2 per pound. This shorter term market is a billion
dollar one itself; imports of carnauba and beeswax to consuming
nations total 20,000 tons.
Sperm whale oil used to be the best natural, high-pressure lubri-
cant available, but now jojoba can tolerate higher tensions without
breaking down and is faster migrating. It requires little or no refim-
ing and is easily sulfurized into lubricants for auto transmissions,
heavy machine parts, and even artificial hearts. As a crankcase ad-
ditive, some vehicles have increased gas mileage by 13%.
Solid jojoba wax is almost identical to polyethylene and can be
mixed with it for cheaper manufacturing of petrochemical-based
plastics. Other uses include detergents, auto and floor waxes, inks,
carbon ribbon coatings, candles, linoleum, varnish, protective
coatings on fruit and paper containers, and sizing for yard goods.
One pharmaceutical manufacturer uses jojoba oil as an ex-
cellent antifoaming agent in the production of penicillin and in
the making of tetracycline. Even the oil extracted meal has value
as an animal feed supplement, yielding 20-30% protein and as a
high-nitrogen fertilizer.

Total production figures for 1984 are not currently available
but should exceed 500,000 pounds of oil .. nowhere enough to
meet demands from cosmetic firms, small oil companies, and
larger corporations doing industrial research and production.
However, pricing for jojoba oil is running at $40-$50 per gallon in
55 gallon drums and during this most recent season seed pricing
remains high at $5-$7 per pound. It takes about 21/2 pounds of
seed to make one pound of oil using current methods of extrac-
tion. There are 7.2 pounds of oil to the gallon. Thus, jojoba oil
selling for $6-$8 per pound makes jojoba the highest priced
agricultural product in the world with the exception of opium
and marijuana.
Current research shows that an acre of plantation jojoba can
produce up to 3,750 pounds of seed when the plants have


reached maturity. Therefore, if you had just one acre producing
only 3,000 pounds it would gross $9,000 to $16,500 in existing
dollars. That is exciting to growers! But let's be realistic and
understand that forecasts by experts for 1990 estimate four
million pounds of jojoba oil to be available, and economists
believe that pricing for seed and oil must drop due to this in-
creased supply and that oil will sell for $1.50-$3.00 per pound by
the mid-1990's. Their predictions are based upon late '70's dollars
and don't count on inflation. If we assume $1.05 per pound for
jojoba seed in 1990 and a yield of 3,000 pounds per acre, the
gross profit per acre would be over $3,150 which is very high
when compared to other cash crops.

Long-Term Investment
An investment in the planting of jojoba must be considered as
a long-term proposition. Forecasts show that an acre of jojoba
should return $1,125 gross cash yield in the fifth year, gradually
increasing to just over $3,150 in the tenth year. We are assuming
750 producing females per acre, each averaging four pounds of
production in the tenth year. Realistically, there should be no
production during the first four years, with plant yield in the
sixth year averaging one pound and increasing to four pounds by
the tenth year.

Jojoba: How to Grow It
There are many unanswered questions regarding jojoba's
domestication as a monoculture crop. Anyone deciding to grow
jojoba should do so with a clear understanding of the risks in-
volved. In fact, all commercial plants should be considered
research projects. Much agricultural research is needed to deter-
mine aspects ofjojoba cultivation such as spacing, male-to-female
ratios, disease and insect control techniques, control chemicals,
water requirements, fertilizer requirements, tissue culture
methods, and sex identification characters. Further, many of
these aspects will vary depending on local temperature, precipita-
tion, and soil type. The following comments and suggestions for
growing jojoba are based on data obtained from farmers and
published sources.

Land Preparation
In nature, jojoba usually is restricted to well-drained, coarse
mixtures of gravel and clay desert soils. Thus, most well-drained
soils should be suitable for jojoba cultivation. The amount of
land preparation necessary depends upon the site condition and
type of irrigation system to be employed. Precise leveling is not
very necessary with sprinkler or drip irrigation systems. I highly
recommend drip irrigation using biwall tubing in the Caribbean
area due to reduced water losses by evaporation.

What to Plant
The basic materials available for planting are seed, seedlings,
and propagated material. Each of these materials offers certain
advantages which are highlighted below. In every case the source
of parent material should be known. The chances of a plantation
yielding large quantities of seed are substantially increased if the
parent is located in a similar environment.

Direct Seeding
Many large plantations have been planted by direct seeding
with the seed placed about one inch below the surface. Soil
should be moist several feet below the surface and should be
amply watered from the time of planting until shoots emerge.
Maintenance of soil moisture is important to provide fast and
deep growth of the tap root, although poorly drained water-
saturated soil will cause the seed to rot and will drown the seed-
ling. The major factor of direct seeding is the reduced cost. The
major disadvantage is possible lack of a uniform stand due to to

low rates of seed germination.


Potted jojoba seeds germinate in almost any well-drained soil
or soil moisture. A mixture that has worked well consists of 25%
topsoil, 25% sand, 25% peatmoss and 25% bark soil conditioner
by volume. Jojoba seed should germinate in one to two weeks if a
morning soil temperature of 80-85 F. is maintained. Jojoba may
be transplanted after three to six weeks in a hothouse. Older
plants have the advantage of hardiness at the time of transplant
and thus may have a higher first year survival rate. A variety of
seed pots are available commercially. Most common are cylin-
drical plastic or square open-ended cardboard sleeves. However,
losing plants from root damage has been a problem. In addition,
pulverized paper or milk-carton type pots which will decompose
if planted directly in the ground (so manufacturers claim) have
been designed. The major advantage to planting a seedling is
that you have planted something that is growing and should con-
tinue to grow, whereas seeds will not all germinate and grow.
Further, the rodent problem is not as severe with seedlings.

Propagated Material
Cuttings-Jojoba has been propagated by making stem tip cut-
tings of new growth. All leaves should be left on the cutting ex-
cept for the length of the stem that is placed in the rooting
medium. A rooting hormone is helpful. Place cuttings in ver-
miculite or sand and, if possible, keep them under mist condi-
tions or keep the root medium saturated. Rooting by this method
may take approximately 30 days and is often successful without
.expert attention.
Tissue culture-Tissue culture is a highly specialized laboratory
technique. Plants are cultivated on a culture medium from shoot
tips, lateral buds, and nodes of mother plants. Although still in
an experimental stage, tissue culture potentially offers a
"prescription approach" to plant selection whereby combinations
of disease resistance, high yield, growth form, site specificity, and
sex determination could be controlled.

How to Plant
Plant spacing is one of the major unknown factors. Researchers
differ in opinion as to how many rows and plants of jojoba to
have per acre. The most widely accepted approach is to have 800
to 900 shrubs per acre with a ratio of female to male of 6:1, or 750
female plants. With this technique, rows would be 10 feet apart
with plants spaced 5 feet apart in each row. Some have gone to 5
foot spacing of rows 20 feet apart so that they could intercrop.
Others have found an intercrop detrimental to growth. Plant and
row spacing continues to be guesswork. In the second and third
year after planting seeds, remove excess or unhealthy plants. You
must wait two or three years before thinning because until the
shrubs flower, you cannot tell whether they are male or female.
Females have a small, bell-shaped blossom while males have a
cluster of tiny flowers.

Native jojoba populations have been known to grow in areas
with less than 12 inches of rainfall per year, but little is known
about their ability to produce seed during periods of drought.
Plantation may survive and produce seed in areas with only 15 to
20 inches of rainfall, but areas with less rainfall will almost cer-
tainly require supplemental irrigation.

Natural populations of jojoba grow in areas of marginal fertili-
ty. Greenhouse experiments indicate that jojoba responds to

nitrogen and phosphorus treatments.


Enough cultivation should be provided throughout the years to
reduce the competition from weeds, whose growth will be
enhanced by irrigation. Pre-emergent herbicides have been used
with some success.

Male:Female Ratios
Jojoba is a wind-pollinated plant. Only the females produce
the seed; the males provide the pollen. Thus both male and
female plants are necessary in the plantation. Since light breezes
carry the pollen several feet, male plants should be present every
few feet on the row ranging from 1 male to 7 females to a 1:5
ratio. The optimum number of male plants per acre and their
planting pattern may have to be determined on the basis of
prevailing wind direction, velocity and frequency.

Seed Production
Since jojoba is still a wild species, the response of individual
plants to cultivated conditions will vary greatly, and it can be ex-
pected that seed productivity will vary greatly between female
shrubs. The first year of blooming should occur during the plant's
second or third winter. The first seed set will amount to only a
handful with seed production increasing each year until plant
maturity at 10 to 12 years of age.

At present, most native stands are hand-harvested. Mechanical
harvesting on some plantations is being attempted using
modifications of existing fruit and nut picking equipment such as
plastic nets, sweepers, vacuums, or shakers. Continuing work is
being done with improvements on such equipment.
Exaggerated claims about the ease of growing jojoba commer-
cially could not be further from the truth. Jojoba will grow with
very little care and sparse water, but the key word is commercial.
There are many factors involved in developing a plantation that
has consistent commercial yield, which is vital to any cash crop.

Site selection is the key to maximum commercial yield. Early
Caribbean commercial producers will benefit most from current
high prices. A price drop will improve prospects for those with
the foresight to plan for it. With careful planning and ongoing
Management of a jojoba investment, your plantation just might
turn you into a unique sort of oil tycoon who capitalizes on a
renewable resource instead of drilling holes in the ground or
destroying majestic sea creatures.

Status ofJojoba Growing in the U.S. Virgin Islands
The original intention of attempting to grow jojoba on St.
Croix was to have the oil source near existing commercial markets
on the U.S. East Coast, thereby reducing transportation costs of
either seeds or oil. Through the assistance of Dr. Darshan Padda
of the C.V.I. and the Extension Service, two experimental plots
were made available for the planting of seeds, each on successive
years. Each plot was approximately one-half acre in size. The
1981 plantings were started in seed pots while the 1982 plantings
were directly seeded into the ground. In both cases, minimum at-
tention was given to the seedlings after they germinated, i.e., on-
ly rainfall watering, no fertilizer and minimum cultivation. This
was really a difficult test but we wanted them handled under
almost adverse situations. The three year old shrubs, now over a
meter tall, have blossomed and need only to be culled and sorted
by sex to increase production and to allow additional experimen-
tation to occur.
Another one-half acre planting was made by direct seeding
through the helpful assistance of the Department of Agriculture
in St. Croix. I was advised of total failure of this attempt due to
the cows in an adjacent pasture succeeding in breaking down a
fence and eating the seedlings.

The encouragement and assistance of the University of Arizona, Office
of Arid Lands Studies in Tucson, Arizona, is greatly appreciated. Much
helpful information was provided by them, as regards current projects
and past histories.


Etude Preliminaire a I'Utilisation de Deux Baculovirus

dans la Lutte Contre Spodopterafrugiperda

en Prairie Guyanaise a Digitariz swazilandensis

D. Dauthuille
Entomologie Appliquee, ORSTOM BP

Deux baculovirus, une granulose (GV) et une polyedrose nucleaire
(NPV) ont ett isoles parmi les pathogenes presents sur Spodoptera
frugiperda (J.E. Smith) en Guyane frangaise. Les tests realises au
laboratoire montrent que la granulose provoque une mortality larvaire
differed accompagnee d'une augmentation du nombre de states larvaires.
Une reduction de consommation est observable chez les larves atteintes
de cette maladie. La mortality survient plus rapidement pour les larves
atteintes de polyedrose nucleaire. Les deux germes provoquent une mor-

J. F. Silvain
165 Cayenne 97323 Guyane Frangaise

talite plus important sur des larves de jeunes states. La presence des
germes dans les conditions naturelles reste insuffisante pour reguler les
populations larvaires de Spodoptera frugierda sur prairies artificielles I
Digitaria swazilandensis Stent, suggerant la necessity d'une intervention
en vue de proteger cette culture. Les modes d'utilisation des deux
baculovirus sont envisages pour la lutte contre Spodopterafrugiperda en
prairie guyanaise.

Spodoptera frugiperda (J. E. Smith) est le principal ravageur
des graminees cultivees en Guyane frangaise. Ses digits, allant
parfois jusqu' k la defoliation total, sont frequemment observes
sur praires artificielles, sur mats et sur riz. Sa presence quasi per-
manente au course de l'ann&e (Silvain et Thiberville, 1983), et son
extreme polyphagie (Pitre et al., 1983) en font un obstacle au
developpement agricole de cette region.
Parmi les moyens mis en oeuvre pour lutter centre ce ravageur,
les insecticides chimiques assurent un control efficace en culture
de mats (Janes et Greene, 1969, Harrel et al., 1977). Cependant
des traitements repetes a matiere active, sont souvent necessaires
a l'obtention de bons resultats (Janes, 1973.)
Les doses employees doivent etre augmentees lorsque la density
et la hauteur du feuillage presentent des valeurs levees (Young,
1979), ce qui est les cas dans les prairies artificielles a Digitaria
swazilandensis Stent. Ces considerations, et les phenomenes de

resistance de plus en plus frequemment observes vis-a-vis des in-
secticides chimiques, impliquent I'elaboration d'une stategie de
lutte integrfe contre Spodoptera frugiperda. Les en-
tomopathogenes ont a jouer un role important dans l'application
d'un tel concept. Parce que frequemment responsables
d'epizooties naturelles (Gardner and Fuxa, 1980), sans danger
pour l'environnement (Burges et al., 1980), specifiques
(FAO/OMS, 1973), faciles a produire et a appliquer (Shieh and
Bohmfalk, 1980), les baculovirus ont fait l'objet d'une attention
toute particulicre de notre part.

Pathologies des Infections a Baculovirus
Parmi les sept baculovirus ayant une action pathogene sur
Spodoptera frugiperda (Tableau 1), les deux viroses, granulose
GV et polyedrose nucleaire NPV, propres a l'insecte, sont
presents en Guyane Francaise.

TABLEAU 1. Liste des baculovirus pathogenes de Spodoptera frugiperda.


S. frugiperda GV
Heliothis armiger GV

S. frugiperda NPV
H. armiger NPV
Autographa californica NPV
Trichoplusia ni NPV
Mamestra brassicae NPV


Steinhaus 1957
Hamm 1982

Chapman and Glaser 1915 *
Hanm 1982
Benton and Reichelderfer 1973
Benton and Reichelderfer 1973
Ferron et al. 1983

* Virus presents en Guyane frangaise



Cas de la granulose Les larves atteintes de granulose prennent
I'aspect caracteristique decrit par Hamm (1968). La presence du
germe se traduit par un allongement de la duree de vie larvaire.
Pour des larves de deuxieme stade alimentees durant 24 heures
sur des feuilles de Digitaria swazilandensis traitees par trempage
dans une suspension de granules, la mortality survient en
moyenne 3,14 jours apres le temps de nymphose moyen des te-
moins (Tableau 2). Le temps letal 50 (TLso) est compris entire 18
et 20 jours post inoculation (Fig. 1). Cette augmentation de la
durEe de vie larvaire s'accompagne d'une augmentation du nom-
bre de mues.

Les larves infectees peuvent ainsi frequemment atteindre des
states 8 et 9. Un dixieme stade a meme tet obtenu apres inocula-
tion, toujours par ingestion de larves du troisieme stade (Tableau
3). La presence du germe se traduit done par un stress analogue a
celui observe lorsque les larves ont une alimentation non adapt&e
(Pencoe and Martin, 1981) ou insuffisant (Labrador S., 1967).

Une reduction notable de consommation est observee chez les
larves ayant contract la maladie, bien que la taille finale atteinte
par celles-ci soit parfois bien superieure a celle des larves temoins.
Les tailles des capsules cephaliques des larves effectuant une serie
de mues surnumeraires presentent des valeurs s'ecartant de celles
observees sur les temoins sains. Ce resultat montre l'extreme
prudence don't il faut user lors d'une determination precise des
states larvaires de chenilles presentant des affections virales.
Comme cela est frequemment le cas chez les larves atteintes de
baculovirus, la mortality baisse lorsque fl'gedes larves augmente.
La mortality observable pour des larves de deuxieme stade nour-
ries pendant 24 heures sur feuillage traiter l'aide d'une solution
virale titrant 17, 12 mg de chenille granulos&e par ml, est de 97, 7
% (Fig. 2). Ce taux passe a 90 % lorsque des states 3 sont
utilises. Aucun effect letal n'est observe lorsque des states 5 sont
soumis au meme protocole experimental. Pour un stade donne,
la mortality provoquee par GV augmente en function de la dose
d'application (Fig. 3).

TABLEAU 2. Comparaison des dur6es de developpement larvaire post traitement
de S. frugiperda mourant de granulose ou atteignant le stade nymphal.

Duree de developpement larvaire post traitement en jours Durde

9 10 12 14 15 16 17 18 19 20 21 22 23 24 25 26 27 myenne

traitees 1 1 1 1 1 4 4 6 4 6 2 2 3 2 2 1 1 19,09
Nombre de larves
t4moins 2 6 3 9 15,95

Traitement effect~ per 8o au stade 2.

FIG. 1. Evolution de la mortality larvaire de S frugiperda par GV au course du temps.

I 100
Mortalit] cumulde %



10 Dur4e de d4veloppement larvaire
I post traitement en jours.
8 10 12 14 16 18 20 22 24 26
TL 50
TN = Temps a partir duquel tous lea thmoins se sont nymphoses.



TABLEAU 3. Nombre de states effectues par des larves de S. frugiperda ayant ou non subi un traitement (GV), au stade 3.

Nuafro da ttad final
atteint par ler larves Moyenne
6 7 8 9 10

timoins 0 20 0 0 0 7
Nombre de larves
granulosdes 1 7 8 1 1 7,66

Mortality %


FIG. 2. Evolution de la mortal-
ite larvaire de S. frugiperda pro-
voquie par une solution de GV, 50-
en function du stade d'applica-
tion per os.


2 3 5 Stade larvaire

FIG. 3. Evolution de la mortality larvaire de S. frugiperda en function de la dose pour des larves trait&es au stade 1.

Mortality % (probit)







10 DBLC Droite de RBgresslon Lindaire Calcul4e.

5-07 6 Log do (g de larv rano

3,38 4,07 4,76 547 6,16 Log dose (as de larve granuloade/ml)