• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Letter of transmittal
 Credits
 Main
 Index














Group Title: Annual report, University of Florida. Agricultural Experiment Station.
Title: Annual report for the fiscal year ending June 30th ...
ALL VOLUMES CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027385/00017
 Material Information
Title: Annual report for the fiscal year ending June 30th ...
Series Title: Annual report for the fiscal year ending June 30th.
Alternate Title: Florida Agricultural Experiment Stations annual report
Physical Description: 23 v. : ill. ; 23 cm.
Language: English
Creator: University of Florida -- Agricultural Experiment Station
Publisher: The Station
Place of Publication: Gainesville Fla
Publication Date: 1931
Frequency: annual
regular
 Subjects
Subject: Agriculture -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
 Notes
Statement of Responsibility: University of Florida, Gainesville, Florida, Agricultural Experiment Stations.
Dates or Sequential Designation: 1931-1967.
 Record Information
Bibliographic ID: UF00027385
Volume ID: VID00017
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltuf - AMF8114
oclc - 12029671
alephbibnum - 002452809
lccn - sf 91090332
 Related Items
Preceded by: Report for the fiscal year ending June 30th ...
Succeeded by: Annual research report of the Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida

Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Title Page
        Page 1
    Letter of transmittal
        Page 2
    Credits
        Page 3
        Page 4
    Main
        Page 5
        Page 6
        Page 7
        Page 8
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    Index
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Full Text










UNIVERSITY OF FLORIDA
GAINESVILLE, FLORIDA



AGRICULTURAL EXPERIMENT
STATION







45th ANNUAL REPORT
FOR THE FISCAL YEAR ENDING
JUNE 30, 1931








LIST OF DEPARTMENT REPORTS
Page
Report of Director .......................... .... .................................. 5
Report of Business Manager ............................... ...................... 14
Publications ...................................................................... 20
Library ........................................................... ............. 28
Agricultural Economics ............................................................ 30
Agronom y .............................. ..................................... . 33
Animal Husbandry ................................................. .............. 48
Chemistry ..................................... ................................ 57
Cotton Investigations ........................................................ ...... 67
Entomology ........................................ 70
Home Economics .................................................................... 81
Horticulture ..................................................................... 87
Plant Pathology .................................................................... 105
Citrus Experiment Station .......................... ............................. 124
Everglades Experiment Station ...................................................... 128
Sub-Tropical Experiment Station .................................................... 172
Tobacco Experiment Station .......................................................... 174






Hon. Doyle E. Carlton,
Governor of Florida,
Tallahassee, Florida.

Sir: I have the honor to transmit herewith the annual report
of the Director of the University of Florida Agricultural Experi-
ment Stations for the fiscal year ending June 30, 1931.
Respectfully,
P. K. YONGE,
Chairman, Board of Control.




Hon. P. K. Yonge,
Chairman, Board of Control.

Sir: I have the honor to transmit herewith the annual report
of the Director of the University of Florida Agricultural Experi-
ment Stations for the fiscal year ending June 30, 1931, and I
request that you transmit the same, in accordance with law, to
His Excellency, the Governor of Florida.

Respectfully,
JOHN J. TIGERT,
President, University of Florida.








EXECUTIVE STAFF
John J. Tigert, M.A., LL.D.. President of the
University
Wilmon Newell, D.Sc., Director
H. Harold Hume, M.S., Asst. Dir., Research
Sam T. Fleming, A.B., Asst.Dir., Administration
J. Francis Cooper, M.S.A., Editor
R. M. Fulghum, B.S.A., Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Secretary
K. H. Graham, Business Manager
Rachel McQuarrie, Accountant



MAIN STATION, GAINESVILLE

AGRONOMY
W. E. Stokes, M.S., Agronomist
W. A. Leukel, Ph.D., Associate
G. E. Ritchey, M.S.A., Assistant*
Fred H. Hull, M.S., Assistant
J. D. Warner, M.S., Assistant
John P. Camp, M.S., Assistant

ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Veterinarian in Charge
E. F. Thomas, D.V.M., Assistant Veterinarian
R. B. Becker, Ph.D., Associate in Dairy Inves-
tigations
W. M. Neal, Ph.D., Asst. in Animal Nutrition
C. R. Dawson, B.S.A., Assistant in Dairy In-
vestigations
CHEMISTRY
R. W. Ruprecht, Ph.D., Chemist
R. M. Barnette, Ph.D., Associate
C. E. Bell, M.S., Assistant
J. M. Coleman, B.S.. Assistant
H. W. Winsor, B.S.A., Assistant
H. W. Jones, M.S., Assistant

ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural Economist
Bruce McKinley, A.B., B.S.A., Associate
M. A. Brooker, Ph.D., Associate
Zach Savage, M.S.A., Assistant

ECONOMICS, HOME
Ouida Davis Abbott, Ph.D., Head
L. W. Gaddum, Ph.D., Biochemist
C. F. Ahmann, Ph.D., Physiologist

ENTOMOLOGY
J. R. Watson, A.M., Entomologist
A. N. Tissot, Ph.D., Assistant
H. E. Bratley, M.S.A., Assistant
E. F. Grossman, M.A., Asso., Cotton Insects
P. W. Calhoun, Assistant, Cotton Insects

HORTICULTURE
A. F. Camp, Ph.D., Horticulturist
Harold Mowry, B.S.A., Associate
M. R. Ensign, M.S., Associate
A. L. Stahl, Ph.D.. Assistant
G. H. Blackmon, M.S.A., Pecan Culturist
C. B. Van Cleef, M.S.A., Greenhouse Foreman

PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist
George F. Weber, Ph.D., Associate
R. K. Voorhees, M.S., Assistant
Erdman West, M.S., Mycologist

*In cooperation with U.S.D.A.


BOARD OF CONTROL
P. K. Yonge, Chairman, Pensacola
A. H. Blanding, Bartow
W. B. Davis, Perry
Raymer F. Maguire. Orlando
Frank J. Wideman, West Palm Beach
J. T. Diamond, Secretary, Tallahassee



BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY
L. O. Gratz, Ph.D., Associate Plant Pathologist
in Charge.
R. R. Kincaid, M.S., Asst. Plant Pathologist
W. A. Carver, Ph.D., Asso. Cotton Specialist
R. M. Crown, B.S.A., Asst. Agronomist, Cotton
Jesse Reeves, Farm Superintendent

CITRUS STATION, LAKE ALFRED
John H. Jefferies, Superintendent
Geo. D. Ruehle, Ph.D., Asst. Plant Pathologist
W. A. Kuntz, A.M., Asst. Plant Pathologist
B. R. Fudge, Ph.D., Assistant Chemist
W. L. Thompson, B.S., Assistant Entomologist

EVERGLADES STATION, BELLE GLADE
R. V. Allison, Ph.D., Soils Specialist in Charge
R. W. Kidder, B.S., Farm Foreman
R. N. Lobdell, M.S., Associate Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist--
H. H. Wedgeworth, M.S., Asso. Plant PatI.
B. A. Bourne, M.S., Associate Sugarcatfe Physi-
ologist
J. R. Neller, Ph.D., Associate Biochemist
A. Daane, Ph.D., Associate Agronomist
M. R. Bedsole, M.S.A., Assistant Chemist
SUB-TROPICAL STATION, HOMESTEAD
H. S. Wolfe, Ph.D., Asso. Horticulturist in Chg.
L. R. Toy, B.S.A., Assistant Horticulturist
Stacy 0. Hawkins, M.A., Assistant Plant
Pathologist



FIELD STATIONS

Leesburg
M. N. Walker, Ph.D., Asso. Plant Pathologist
W. B. Shippy, Ph.D., Asst. Plant Pathologist
K. W. Loucks, M.S., Asst. Plant Pathologist
C. C. Goff, M.S., Assistant Entomologist
J. W. Wilson, Ph.D., Assistant Entomologist
Plant City
A. N. Brooks, Ph.D., Asso. Plant Pathologist
R. E. Nolen, M.S.A., Field Asst. in Plant Path.
Cocoa
A. S. Rhoads, Ph.D., Asso. Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Asso. Plant Pathologist
West Palm Beach
D. A. Sanders, D.V.M., Associate Veterinarian

Monticello
Fred W. Walker, Assistant Entomologist
Bradenton
David G. Kelbert, Asst. Plant Pathologist








THE FLORIDA AGRICULTURAL EXPERIMENT STATION is a
part of the University of Florida College of Agriculture-it
is the research division of the College, which consists also
of the divisions of resident teaching and agricultural exten-
sion (including county and home demonstration agent work).
The Station works in cooperation with the office of Experi-
ment Stations, United States Department of Agriculture.
The Florida Agricultural Experiment Station was estab-
lished in the fall and winter of 1887 as a part of the old
Florida College of Agriculture which was then located at
Lake City. Its establishment followed the passage by Con-
gress on March 2, 1887, of the Hatch Act making funds
available to each state agricultural college for the establish-
ment of an agricultural experiment station. These funds
became available on October 1, 1887. On March 16, 1906,
Congress passed the Adams Act, which appropriated still
more moneys for state agricultural experiment stations.
With the passage of the Purnell Act, February 24, 1925,
federal funds for state experiment stations were further
increased. The State of Florida appropriates thousands of
dollars annually for the operation of the Experiment Station.
When the State Legislature of 1905 passed the Buckman
Act, all existing state institutions of learning were abolished
and in their stead were established the University of Florida
at Gainesville, the State College for Women at Tallahassee,
and the Florida A. & M. College for Negroes at Tallahassee.
The College of Agriculture became a part of the University
of Florida. As a consequence, in December, 1906 and the
first three months of 1907 the Agricultural Experiment
Station was transferred to Gainesville.
The Station now has four branch stations and seven field
laboratories, as shown on the staff page.










45th Annual Report for the Fiscal Year

Ending June 30, 1931





Dr. John J. Tigert,
President, University of Florida.
Sir: I have the honor to transmit herewith my report on the
work and investigations of the University of Florida Agricultural
Experiment Stations, together with the reports of the heads of
the several departments, for the fiscal year ending June 30, 1931.
Respectfully,
WILMON NEWELL,
Director.

INTRODUCTION
A summary of the activities of the various departments in the
Experiment Station and Branch Stations, and reports of the
progress that has been made with the projects under investigation
are given in the following pages.
The financial resources of the Experiment Stations for the fiscal
year just closed, including balances carried forward from the
previous year, have been as follows:
Federal Adams Fund ...........................$ 15,000.00
Federal Hatch Fund ............................. 15,000.00
State Funds, Main Station, Gainesville............. 321,064.29
State Funds, Citrus Station, Lake Alfred........... 16,190.25
State Funds, Everglades Station, Belle Glade......... 73,901.56
State Funds, Tobacco Station, Quincy................ 28,017.14
State Funds, Subtropical Station, Homestead....... 21,885.93
State Funds, Watermelon Investigations, Leesburg.. 11,184.44
Incidental Funds, Sales, Etc. ...................... 25,826.13
$528,069.74
Federal Purnell Funds, not included above.......... 60,000.00

SUPERVISION OF RESEARCH WORK
With the expansion of research work under way at the Main
Station and its branches during recent years, and the increasing
volume of research work conducted by the Teaching Division of






Florida Agricultural Experiment Station


the College of Agriculture, the problem of supervising and corre-
lating all research work has become a matter of major importance.
The Station has been fortunate in securing the services of H.
Harold Hume, who joined the Staff on March 1, 1931, as Assistant
Director, Research. Mr. Hume has also been appointed Assistant
Dean, Research, for the College of Agriculture and will devote
all of his time in connection with the supervision and direction of
research work in the entire College of Agriculture.

FIELD LABORATORIES
In addition to the Main Station and its branch stations, which
constitute the permanent locations for research activities, tem-
porary locations are selected from time to time for the conduct
of work on special problems requiring immediate field contact not
available at the permanent stations. At present such field sta-
tions, or laboratories, are in operation at the following points:
Hastings-For the investigation of diseases of Irish potatoes.
Cocoa--Certain diseases of citrus.
Bradenton-Tomato diseases.
Plant City-Diseases of strawberries.
Monticello-Insect pests of pecans.
Pierson-Insect pests of ferns and ornamentals.
West Palm Beach-Certain diseases of livestock.
Leesburg-Watermelon diseases and insect pests, and diseases
of ferns and ornamentals.
With the exception of the Leesburg Field Laboratory, there is
no permanent investment in land or buildings at field laboratories
and it is the Station's policy to close out the work at such points
and remove the personnel and equipment as soon as the purpose
for which the field laboratory was established has been accom-
plished.
At Leesburg, however, the Board of Control authorized the
acceptance of land offered by the local people as a site for the
laboratory and a permanent laboratory building and greenhouse
have been constructed. In view of these permanent investments,
the Leesburg Field Laboratory promises to become a permanent
site for such research activities as can be handled to best advan-
tage there. These will include, for the present, the investigation
of watermelon diseases and insect pests, and diseases of ferns and
ornamentals, as indicated above.
Reports of progress on the work at all field laboratories are in-
cluded in the reports of the various departments concerned.






Forty-fifth Annual Report, 1931


CHANGES IN STAFF
During the fiscal year ending June 30, 1931, the following
changes took place in the Station staff:
M. R. Bedsole was appointed Assistant Chemist, Everglades
Station, September 16, 1930.
B. A. Bourne was appointed Associate Plant Physiologist Sugar-
cane Investigations, September 15, 1930. Located at Everglades
Station.
Marvin A. Brooker, Assistant Agricultural Economist, was
granted leave without pay from February 1, 1931, to May 31, 1931,
to complete his residence requirements at Cornell University to-
wards his Doctor's Degree.
Dr. A. Daane was appointed Associate Agronomist at the Ever-
glades Station November 13, 1930.
J. B. Hester, Assistant Chemist, Soils, was granted leave with-
out pay September 15, 1930, to June 15, 1931. This leave was
later extended to July 1, 1932.
H. H. Hume was appointed Assistant Director, Research, March
1, 1931.
H. W. Jones was appointed Assistant Chemist, Soils, October 1,
1931, by transfer from the Synthetic Nitrogen Fellowship.
F. W. Kelley was appointed Greenhouse and Shop Foreman,
Everglades Station, July 1, 1930.
R. W. Kidder was appointed Farm Foreman at the Everglades
Station August 15, 1930.
Dr. J. R. Neller was appointed Associate Biochemist at the
Everglades Station September 8, 1930.
R. E. Nolen was transferred from the position of Laboratory
Assistant in Pecan Disease Investigations, Monticello, to the posi-
tion of Laboratory Assistant in Strawberry Disease Investiga-
tions, Plant City, July 1, 1930.
E. R. Purvis resigned as Assistant Chemist, Everglades Station,
September 15, 1930.
Dr. George D. Ruehle was appointed Assistant Plant Pathol-
ogist, with headquarters at the Citrus Station, July 1, 1930.






8 Florida Agricultural Experiment Station

Zach Savage was appointed Assistant Agricultural Economist
February 1, 1931.
A. N. Tissot, Assistant Entomologist, was granted leave without
pay from January 1, 1931, to September 1, 1931, for the purpose
of continuing his studies towards his Doctor's degree at Ohio State
University.
John L. Wann, Assistant Agricultural Economist, was trans-
ferred to the Teaching Division of the College of Agriculture
February 1, 1931.
Dr. H. S. Wolfe was appointed Associate Horticulturist, Sub-
Tropical Experiment Station, October 1, 1930. Appointed Asso-
ciate Horticulturist in Charge of the Sub-Tropical Station March
16, 1931.
Fred Yount resigned as Office Assistant at the Everglades Sta-
tion May 31, 1931.





SCOPE OF THE STATION'S WORK, JULY 1, 1930, TO JUNE 30, 1931.

A list of the principal projects carried on during the year is given below, arranged according to depart-
ments. Page reference is given to a brief discussion of the work under each project.


Department
AGRICULTURAL
ECONOMICS


AGRONOMY


















ANIMAL
HUSBANDRY


Project
Number Title Page
73 Agricultural Survey of Some 500 Farms in the General Farming Region of Northwest Florida 30
104 An Economic Study of Dairy Farming in Florida ..................................... 30
123 A Study of Florida Truck Crop Competition ........................................ 31
154 Farmers' Cooperative Associations in Florida ............................................. 31.
16 Peanut and Corn Fertilizer Experiments .............................................. 43
20 Plant Breeding-Peanuts .......................................................... 45
27 Pasture Experiments ..... .... ........................................ 35
43 Effect of Landplaster or Gypsum on Hay and Seed Production of Peanut Varieties .......... 45
53 Winter Legume Studies ........................................................... 45
54 Summer Cover Crop Studies ..................................... .................... 47
56 Variety Test Work with Farm Crops ....................................... .......... 34
97 Sources of Nitrogen and Rates of Application of Nitrogen as Top-Dressing for Oats ....... 40
100 Growth Behavior of Bahia Grass ................................................... 40
105 Improvement of Corn Through Selection and Breeding .............................. 42
106 Effect of Time of Planting of Corn on Forage and Grain Yields ......................... 43
107 Crop Adaptation Studies ........................................................... 33
120 Fertilization of Pasture Grasses ......... ........................................... 39
138 The Effect of Potash on the Yield and Quality of Peanuts ................ ............. 44
153 Date of Seeding and Phosphate Requirements of Winter Legumes and Their Effect upon Sub-
sequent Crops ................................................................... 46
158 Lysimeter Studies on Pasture Grasses .............................................. 39
159 Ratio of Organic to Inorganic Nitrogen in Mixed Fertilizers for Cotton ................ .. 45
163 Corn Fertilizer Experiments ............. ......................................... 43
174 A Study of Crotalaria as a Forage Crop .............................................. 47
176 Mutations Induced by Heating Seed Corn ............................................. 41
119 Paralysis of the Domestic Fowl................. ................... ..... ....... ... 56
122 The Cost of Wintering Steers Preparatory to Summer Fattening on Pasture .............. 54
133 Deficiencies in Feeds Used in Cattle Rations .......................................... 52
135 Soybean Silage for Dairy Cows...................................................... 51






Department

ANIMAL
HUSBANDRY
(Continued)




CHEMISTRY














COTTON INVEST
GATIONS




ENTOMOLOGY


Project
Number Ti tle
136 Comparison of Various Grazing Crops with Dry Lot Feeding for Pork Production.........
137 The Value of Grazing for Fattening Cattle in Beef Production .........................
140 Relation of Conformation and Anatomy of the Dairy Cow to Her Milk and Butterfat
Production .....................................................................
149 Anaplasmosis in Cattle ..............................................................
160 Fattening Fall Pigs for Spring Market...............................................
175 A Study of the Feeding Value of Crotalaria...........................................


a


*age
53
54

51
55
54
52

57

58
58

59
59
59
60
61
62
64
64
65

65

181
181
67
69
69


Dieback of Citrus ................. ................................................
Determination of the Effect of Varying Amounts of Potash on the Composition and Yield
and Quality of the Crop ..........................................................
Determination of the Fertilizer Requirements of Satsuma Oranges .......................
Determination of the Effect of Various Potash Carriers on Growth, Yield and Composition
of Crops .................. ................................... ....... ...
Study of Fertilizer Requirements of Citrus Trees When Grown on Muck Soils............
Composition of Crops as Influenced by Fertilization and Soil Types-Pecans..............
Effect of Various Fertilizer Formulas.............................................
Concentrated Fertilizer Studies........................................................
Determination of the Effect of Green Manures on the Composition of the Soil.............
Effect of Various Fertilizer Treatments and of Soil Amendments on Tomatoes............
Effect of Fertilizers and Soils on Composition of Truck Crops.........................
Study of Iodine Content of Florida Grown Crops .....................................
A Study of the Decomposition of Forest, Range and Pasture Growth to Form Soil Organic
M matter ...........................................................................

Variety Testing and Breeding ................................. .. ......................
Field Tests with Cotton-Spacing and Time of Planting Tests...........................
Control of Cotton Insects ......................................................
Cotton Diseases-Cotton Wilt ...................................................
Cotton Physiology-Nutrition and Growth.............................................
Studies in Inheritance of Cotton ....................................................

Florida Flower Thrips ............................................................
Root-Knot Investigations .............................................................
Introduction and Study of Beneficial Insects .......................................
Larger Plant Bugs on Citrus and Truck Crops ............................... .....
Studies of the Bean Jassid .......................................................





Department
ENTOMOLOGY
(Continued)






HOME
ECONOMICS







HORTICULTURE


Project
Number Title 1
60 The Green Citrus Aphid .............................................................
82 Control of Deciduous Fruit and Nut Crop Insects .....................................
108 Life History Studies of Pycnoscelus surinamensis L. ..................................
155 Mealy Bugs ................................. ........ ................... ..........
156 Green Spider (Tetranychus telarius) on Asparagus Plumosus ...........................
157 Insects of Ornamentals ......... ....................................................
162 Insects and Other Animal Pests of Watermelons ......................................
X Control of the Insect Pests of Stored Corn.............................................

69 Determination and Identification of Organisms which Cause the Spoilage of Canned Vege-
tables in the South ...............................................................
70 Determination of Whether Chlorophyll, Chlorophyll Alpha and Beta, and the Petroleum Ether
Extracts of the Yellow Pigments of Alfalfa Can Be Used as a Source of Vitamin A in
Animal Nutrition .................................... ........... .................
71 A Study of Some of the- Constituents of Citrus Fruits, Loquats, Roselle, and Guava: Pectin,
Oils and Glucosides .............................................................
142 The Relation of Growth to Phosphorus, Calcium and Lipin Metabolism as Influenced by the
Thymus ................ ....................... .................................
44 Field Studies of the Diseases Affecting the Pecan, Including Control Measures ............
45 Field Studies of the Insects Attacking the Pecan, Including Control Measures ............
46 Variety Response of Pecans to Different Soil Types, Localities, Etc. ....................
47 Cooperative Fertilizer Tests in Pecan Orchards .....................................
48 Variety and Stock Tests of Pecan and Walnut Trees .................................
49 Variety Tests of Grapes........................................................
50 Propagation, Planting and Fertilizing Tests with Tung Oil Trees........................
51 Observation and Testing of Various Citrus Hybrids ..................................
52 Testing of Native and Introduced Shrubs and Ornamentals and Methods of Their Propa-
gation .............................. ............................................
58 Variety, Propagation, and Planting Tests of Pear, Avocado, Japanese Persimmon, Fig and
Other Fruits ............................................... ........... ....................
59 Variety Tests of Berries (Rubus spp.) ..................................................
80 Cooperative Cover Crop Tests in Pecan Orchards ......................................
81 Tests of Different Stocks as Rootstocks for Satsuma Oranges ..........................
110 Phenological Studies on Truck Crops in Florida .....................................
111 Fundamental Physiology of Fruit Production ........................................
139 Avocado Maturity Studies ............. ... ..........................................


age
73
74
77
77
77
77
78
79


81

81

81

82
95
95 M
93 hd
93
94 4*
97 k
98 o
92
95
95
97
94
92
100
91 i
98







Department
HORTICULTURE
(Continued)

PLANT
PATHOLOGY




















CITRUS
EXPERIMENT
STATION



EVERGLADES
EXPERIMENT
STATION


Project
Numbe:
164
165

1
3
4
11
19
24
32
114
116
126
128
130
131
143

144
145
146
147
148
150
151
167

26
34
35
83
102
X

84
85
86


r Title I
Rejuvenation Experiments with Neglected Pecan Orchards .............................
Relation of Nitrogen Absorption to Food Storage and Growth.........................

Gumming of Citrus .......................... ........ ...... ... ....................
Melanose and Stem-End Rot of Citrus..................................... ...........
Investigation of Pecan Diseases-Pecan Scab ........................................
Citrus Canker .............. ..................................... ...............
Downy Mildew of Cucurbits ............................ ............................
Citrus Scab and Its Control ...................................................
Citrus Blight, or Chronic Wilt............ ............. ............................
D diseases of Citrus A phids ................ ................ ...........................
Nailhead Spot of Tomatoes ........................................................
Investigations Relative to Certain Diseases of Strawberries of Importance to Florida......
Investigation upon the French Bud, Crimps, or Briar Bud Disease of Strawberries ........
Investigations of Diseases of White Potatoes ................ .............................
Control of Late Blight of Irish Potatoes ..................................................
Investigation of Brown Rot of Potatoes and Related Plants Caused by Bacterium solana-
cearum EFS ..................................... ..............................
Investigation of and Control of a Fungous Disease of Tomatoes Caused by Stemphylium sp.
Investigation and Control of a Disease of Corn Caused by Physoderma zeae-maydis ........
Investigation of Seedling, Stalk and Ear Rot Diseases of Corn Caused by Diplodia spp.....
Investigation of Seedling, Stalk and Ear Rot Diseases of Corn Caused by Fusarium spp....
Investigation of Diseases of Ferns and Ornamental Plants .............................
Fusarium Wilt of Watermelons ............................ .....................
Diseases of W atermelons .............................. .... ......... ........
A Study of the So-called "Rust" of Asparagus phlmosus ................................

Citrus Progeny and Bud Selection.................................. .............
Propagation Experiments with Citrus Plants of Various Kinds ..........................
Tests of Introduced and New Varieties and Hybrids of Citrus and Near-Citrus ............
Cover Crops and Green Manure Studies in Citrus Groves ..............................
Citrus Variety Tests, Including Rootstocks ............... .............. ........
Grove Cultivation Experiments ............................. .......................


'age
94
92

105
107
112
108
113
110
112
112
113
116
118
118
120

120
113
122
122
123
121
114
115
121

124
125
125
126
127


Forage, Truck and Field Ciop Trials.................... ........................... 139
Fruit and Forest Tree Trials............. ............ .. ......................... 141
Field Fertilizer Experiments......................................................... 143






Department

EVERGLADES
EXPERIMENT
STATION
(Continued)










TOBACCO
EXPERIMENT
STATION


Project
Numbe
87
88
89
90
124
125
168

169

170
171
172
173
25
33

57
74
79
101
117
152


SUB-TROPICAL
EXPERIMENT
STATION


r Title I
Insect Pests and Their Control .........................................................
Soil Investigations ...................................................................
Drainage Studies ............................. ...............................
Soils and Crop Studies, Including Rotation, Fertilizer and Cultural Practice Experiments..
Studies Relative to Plant Pathological Problems of the Everglades......................
Investigations Relative to the So-called "Yellows" of Beans ...........................
The Role of Special Elements in Plant Development upon the Peat and Muck Soils of the
Everglades ..................................................................... ..
Studies upon the Prevalence and Control of the Sugar Cane Moth Stalk Borer (Diatraea
saccharalis) in South Florida .......................... ...... ....................
Studies upon the Prevalence and Control of Rodents under Field and Village Conditions....
Cane Breeding Experiments .........................................................
General Physiological Phases of Sugarcane Investigations ..............................
Agronomic Phases of Sugarcane Investigations ......................................


'age
149
152
153
154
156
158

159

160
161
165
168
168


Field and Laboratory Studies of Tobacco Diseases ..................................... 176
Variety Tests of Cigar Wrapper Tobacco for Resistance to Black Shank (Phytophthora
nicotianae Breda de Haan) ............................................... .... 178
Variety Tests and Breeding Experiments of Cotton ................................ 181
Field Tests with Cotton-Spacing and Time of Planting Tests .......................... 181
Cotton Physiology-Nutrition and Growth.............................................
Studies in Inheritance of Cotton....................................................... 183
Fertilizer Experiments with Shade Tobacco.......................................... 183
Studies on the Effects of Certain Chemical Elements on the Growth and Leaf Quality of
Shade-Grown Cigar Wrapper Tobacco.............................................. 184

No approved research projects at close of fiscal year.
Report of Progress ................... ............................................. 172







14 Florida Agricultural Experiment Station


REPORT OF BUSINESS MANAGER

Following is a report of the credits received and expenditures
vouchered out of various Experiment Station funds for the year
ending June 30, 1931.

STATION INCIDENTAL FUND

Receipts
Balance 1929-30 ............................ $ 5,656.99
Receipts July 1, 1930--June 30, 1931........... 20,169.14

$ 25,826.13
Expenditures
Salaries .................................... $ 1,500.00
Labor ....................................... 2,100.76
Stationery and office supplies .................. 58.48
scientific supplies ............................ 110.25
Feeds ............................... ....... 347.00
Sundry supplies .............................. 407.11
Fertilizers .................................. 101.07
Communication service ....................... 6.25
Travel ...................................... 293.72
Transportation of things ...................... 290.57
Publications ..............................
'Heat, light, power ............................ 299.57
Furniture ................................ .... 384.15
Library ..................................... 6.00
Scientific equipment ..........................
Livestock .................................... 1,437.15
Tools ........................................ 339.08
Buildings, alterations ........................ 5,332.29
Contingent ................................... 247.73
Balance ..................................... 12,564.95

$ 25,826.13







Forty-fifth Annual Report, 1931 15

MAIN STATION

Receipts

Balance 1929-30 ............................. $ 53,819.29*
Receipts 1930-31 ........................... 267,245.00
$321,064.29

Expenditures

Salaries ................. .................. $ 140,509.97
Labor ....................................... 37,348.62
Stationery and office supplies .................. 4,428.07
Scientific supplies ............................ 7,249.49
Feeds ....................................... 8,883.89
Sundry supplies ............................. 6,975.51
Fertilizers ................................... 4,626.52
Communication service ........................ 2,937.62
Travel ..................................... 14,845.60
Transportation of things ...................... 2,011.06
Publications ................................. 15,960.00
Heat, light, power ........................... 7,484.81
Furniture ................................... 6,827.98
Library .................................... 4,090.19
Scientific equipment ......................... 4,453.30
Livestock .................................... 686.93
Tools ............... ........................ 10,301.33
Buildings, repairs .......................... 29,301.09
Contingent .................................. 1,901.20
Balance ..................................... 10,241.11
$321,064.29

*Balance shown in previous annual report was $52,015.50. On account of
the fact that supplemental list of vouchers submitted to Board in August
was carried forward for payment, this balance was finally $53,819.29, as
shown herewith.







16 Florida Agricultural Experiment Station

CITRUS STATION

Receipts
Balance 1929-30 .............................$ 240.25*
Receipts 1930-31 .............................. 15,950.00

$ 16,190.25

Expenditures
Salaries .................................. ... $ 5,800.00
Labor ....................................... 4,196.60
Stationery and office supplies ................ 130.35
Scientific supplies ............................ 324.13
Feeds ........ .............................. 490.23
Sundry supplies .............................. 685.96
Fertilizers .................................. 1,303.53
Communication service ....................... 103.60
Travel ...................................... 357.13
Transportation of things ...................... 41.95
Publications ..................................
Heat, light, power ............................ 489.58
Furniture ............... .................... 327.46
Library ...................................... 42.31
Scientific equipment .......................... 338.87
Livestock .................................
Tools ....................................... 546.32
Buildings, repairs ............................ 912.58
Contingent ................................... 99.65
B balance ..................................

$ 16,190.25

*Balance shown in previous annual report was $175.50. On account of
fact that supplemental list of vouchers submitted to Board in August was
carried forward for payment, this balance was finally $240.25, as shown
herewith.







Forty-fifth Annual Report, 1931 17

EVERGLADES EXPERIMENT STATION

Receipts
Balance 1929-30 ............................. $ 5,801.56*
Receipts 1930-31 ............................ 68,100.00
$ 73,901.56
Expenditures
Salaries .................................. $ 27,306.43
Labor ........................................ 12,209.53
Stationery and office supplies .................. 222.90
Scientific supplies ......................:..... 2,056.01
F eeds ....................................... 91.52
Sundry supplies ............................. 3,446.12
Fertilizers ................................... 617.16
Communication service ........................ 248.32
Travel ...................................... 1,325.08
Transportation of things ...................... 632.55
Publications ...............................
Heat, light, power ............................ 2,817.38
Furniture ................................... 4,263.12
Library ...................................... 854.61
Scientific equipment .......................... 1,466.37
Livestock .................................
Tools ....................................... 5,597.55
Buildings, repairs ............................ 10,627.51
Contingent .................................. 111.23
B balance ..................................... 8.17
$ 73,901.56

Everglades Incidental
Balance 1929-30 ............................$ 3,480.60 $ 3,480.60

Expenditures
Labor ...................... ...............$ 25.00
Balance ...................................... 3,455.60
$ 3,480.60

*Balance shown in previous annual report was $3,930.78. On account of
the fact that supplemental list of vouchers submitted to Board in August
was carried forward for payment, this balance was finally $5,801.56 as shown
herewith.







18 Florida Agricultural Experiment Station

SUB-TROPICAL STATION
Receipts
Balance 1929-30 .............................. $ 6,885.93*
Receipts ..................................... 15,000.00

$ 21,885.93
Expenditures
Salaries .................................... $ 4,800.00
Labor ....................................... 5,305.90
Stationery and office supplies .................. 56.49
Scientific supplies ........................... 559.81
F eeds ......................................
Sundry supplies ............................. 1,082.55
Fertilizers .................. ................ 338.83
Communication service ....................... 87.29
Travel .................. .................. 733.38
Transportation of things ...................... 257.17
Publications .................................
Heat, light, power ............................ 591.45
Furniture .................................... 667.49
Library ...................................... 117.21
Scientific equipment .................. ....... 548.41
Livestock ................................... 168.30
Tools, implements ............................ 1,881.49
Buildings, repairs ............................ 4,584.12
Contingent .................................. 102.49
Balance ...................................... 3.55

$ 21,885.93
*Balance shown in previous annual report was $6,843.90. On account of
fact that supplemental list of vouchers submitted to Board in August was
carried forward for payment, this balance was finally $6,885.93, as shown
herewith.
TOBACCO EXPERIMENT STATION
Receipts
Balance 1929-30 ............................. $ 2,417.14
Receipts 1930-31 ............................. 25,600.00

$ 28,017.14
Expenditures
Salaries .................................... $ 8,799.99
Labor ....................................... 4,746.42
Stationery and office supplies .................. 97.11
Scientific supplies ............................ 106.91
Feeds ....................................... 344.51
Sundry supplies .............................. 1,401.17
Fertilizers ................................... 739.93
Communication service ........................ 100.45
Travel ....................................... 382.35
Transportation of things ...................... 294.94
Publications .................................. .95
Heat, light, power ............................ 574.13
Furniture .................................... 192.83
Library ..................................... 242.22
Scientific equipment .......................... 25.76
Livestock .................................... 135.00
Tools ....................................... 1,578.83
Buildings, repairs ............................ 7,926.75
Contingent ................................. 306.95
Balance ...................................... 19.94

$ 28,017.14







Forty-fifth Annual Report, 1931 19

WATERMELON DISEASE INVESTIGATIONS

Receipts

Balance 1929-30 ............................ $ 1,184.44*
Receipts 1930-31 ............................ 10,000.00
$ 11,184.44

Expenditures

Salaries .................................... $ 5,600.00
Labor ..................................... 1,325.95
Stationery and office supplies ................... 80.62
Scientific supplies ............................ 548.51
Feeds ....................................... .90
Sundry supplies .............................. 432.90
Fertilizers ................................... 346.67
Communication service ....................... 42.74
Travel ...................................... 518.27
Transportation of things ...................... 18.20
Publications ..............................
Heat, light, power ............................ 101.81
Furniture .................................... 637.40
Library ...................................... 23.36
Scientific equipment .......................... 390.56
Livestock ....................................
Tools, implements, etc. ........................ 205.38
Buildings, repairs ............................ 742.09
Contingent ................................... 9.39
Balance ..................................... 159.69
$ 11,184.44

*Balance shown in previous annual report was $1,172.54. On account of
fact that supplemental list of vouchers submitted to Board in August was
carried forward for payment, this balance was finally $1,184.44, as shown
herewith.







Florida Agricultural Experiment Station


PUBLICATIONS

The work covered in this report represents that done in ap-
proximately one-half time by the editors and mailing clerks;
they devoted the other half of their time to work for the Agricul-
tural Extension Service.

BULLETIN EDITING

The number of bulletins, 20, published by the Experiment
Station during this fiscal year is almost double the number
printed during any other similar period. With continued work
by members of the staff, information of great value is being
obtained. This information is being made available to the public
in bulletin form as rapidly as possible. The Station has now
published a total of 237 bulletins.
The 20 bulletins published by the Station this year amounted
to 1,222 pages; 200,000 copies were printed. Copy for these
bulletins was edited and layouts were made by the Editors.
Following is a list of bulletins issued during the fiscal year,
showing titles, pages and number of copies of each:

Bul. Title Pages Edition
218 Fertilizer Experiments with Truck Crops......... 88 10,000
219 Growth Behavior and Maintenance of Organic Foods
in Bahia Grass ................................ 56 4,000
220 Effect of Seed Potato Treatment on Yield and Rhiz-
octonosis in Florida from 1924 to 1929............ 36 4,000
221 The Tung-Oil Tree .................. ...... 64 12,000
222 Potato Dusting and Spraying Experiments in
Florida, 1924-1929 ..................40 4,000
223 Miscellaneous Tropical and Sub-Tropical Florida
Fruits ............................ ... 92 15,000
224 Florida Truck Crop Competition I................ 170 8,000
225 Diseases of Watermelons in Florida.............. 52 12,000
226 Development of Strains of Cigar Wrapper Tobacco
Resistant to Blackshank ....................... 48 5,000
227 Citrus Propagation ............................ 48 15,000
228 Native and Exotic Palms of Florida .............. 72 12,000
229 Diseases of Citrus in Florida .................... 212 15,000
230 Spraying and Dusting Cucumbers for the Control
of Downy Mildew from 1925 to 1930............. 60 8,000
231 I-Salt Sick, Its Cause and Prevention; II-Mineral
Supplements for Cattle ......................... 24 10,000
232 Florida Truck and Garden Insects............... 116 20,000
233 Determination of the Winter Survival of the Cotton
Boll Weevil by Field Counts .................... 48 5,000
234 The Two-Spotted Mite on Asparagus Plumosus.... 20 5,000
235 Crimp-A Nematode Disease of Strawberries...... 28 5,000
236 Swine Production in Florida..................... 60 20,000
237 General Properties of Some Semi-Tropical Fruits
of Florida ................................... 32 10,000






Forty-fifth Annual Report, 1931


SUMMARY OF BULLETINS

Brief summaries of the principal points covered in the different
bulletins follow:
218. Fertilizer Experiments with Truck Crops. (J. J. Skin-
ner and R. W. Ruprecht, pp. 68, Figs. 19.) Gives results of expe-
riments in fertilizing celery and lettuce on Leon fine sand, toma-
toes on calcareous Glade soil, and truck crops with manganese
sulphate on calcareous Glade soil.
219. Growth Behavior and Maintenance of Organic Foods in
Bahia Grass. (W. A. Leukel and J. M. Coleman, pp. 56, Figs. 17.)
Reports results of a comparative study of the growth behavior,
production of top growth, variation in weight of stolons and
roots, and the difference in percentages and quantities of organic
stored foods in these plant parts of Bahia grass when such plants
were cut frequently, when allowed to grow to maturity and cut
in the seed stage of growth, and when grown to maturity and sub-
jected to no cutting treatment.
220. Effect of Seed-Potato Treatment on Yield and Rhizocto-
nosis in Florida from 1924 to 1929. (L. O. Gratz, pp. 36, Figs. 2.)
While rhizoctonosis occurs to some extent in Florida, the results
reported in this bulletin show that treatment of seed potatoes
with corrosive sublimate, hot formaldehyde, or organic mercury
compounds is not justified.
221. The Tung-Oil Tree. (Wilmon Newell, Harold Mowry, and
R. M. Barnette, pp. 64, Figs. 33.) Describes the tree, cites its
relationships and adaptability, lists the uses of tung oil, describes
early plantings in Florida, gives hints on varieties, culture, ex-
pressing the oil, diseases and insects.
222. Potato Spraying and Dusting Experiments in Florida,
1924 to 1929. (L. O. Gratz, pp. 40, Figs. 3.) Reviews results of
six years' experimental work in spraying and dusting for the
control of late blight, early blight, tip-burn, and hopper-burn.
Indications are that both methods are profitable, but spraying
gives better control at less cost.
223. Miscellaneous Tropical and Sub-Tropical Florida Fruits.
(Harold Mowry and L. R. Toy, pp. 92, Figs. 74.) Discusses
climatic restrictions, propagation, and culture of these plants.
Describes in detail 42 species, with references to 52 other species.
224. Florida Truck Crop Competition I. Inter-State and
Foreign. (C. V. Noble and Marvin A. Brooker, pp. 170, Figs. 73.)
Tabulates shipments of principal truck crops from different
sources during time each crop is being shipped from Florida, thus






Florida Agricultural Experiment Station


giving idea of areas which compete with Florida. Crops covered
are string beans, cabbage, celery, cucumbers, eggplants, lettuce,
green peas, peppers, early white potatoes, strawberries, tomatoes,
watermelons, cantaloupes, cauliflower, and onions.
225. Diseases of Watermelons in Florida. (M. N. Walker and
George F. Weber, pp. 52, Figs. 30.) Describes the different dis-
eases attacking watermelons and, where known, gives control
measures. Also discusses cold, wind, and sand injury, handling
melons, seed disinfection, and fungicides and their application.
226. Development of Strains of Cigar Wrapper Tobacco Re-
sistant to Blackshank (Phytophthora nicotianae Breda de Haan.)
(W. B. Tisdale, pp. 48, Figs. 12.) Reports methods and results
of experiments in developing strains of cigar wrapper tobacco
resistant to blackshank.
227. Citrus Propagation. (A. F. Camp, pp. 48, Figs. 29.) A
well illustrated treatise on citrus propagation.
228. Native and Exotic Palms of Florida. (Harold Mowry,
pp. 72, Figs. 66.) Bulletin 184 revised and brought up-to-date,
with new species listed. Contains sections on propagation, plant-
ing, and fertilizing.
229. Diseases of Citrus in Florida. (A. S. Rhoads and E. F.
DeBusk, pp. 212, Figs. 101.) Discusses the different diseases of
citrus trees and fruit, giving control measures where known. Also
discusses cultural practices in relation to disease prevention.
230. Spraying and Dusting Cucumbers for the Control of
Downy Mildew from 1925 to 1930. (George F. Weber, pp. 60,
Figs. 1.) Reports results of a number of tests with different
sprays and dusts; shows which are most effective.
231. I-Salt Sick, Its Cause and Prevention; II-Mineral Sup-
plements for Cattle. (R. B. Becker, W. M. Neal, and A. L. Shealy,
pp. 24, Figs. 13.) Reports the discovery of the cause of salt sick,
with a method for preventing and curing the trouble. Lists the
mineral supplements needed by cattle, and the part each mineral
plays.
232. Florida Truck and Garden Insects. (J. R. Watson, pp. 116,
Figs. 59). Discusses the insects attacking various truck and gar-
den crops, and gives measures for the control of these pests.
233. Determination of the Winter Survival of the Cotton Boll
Weevil by Field Counts. (Edgar F. Grossman and P. W. Cal-
houn, pp. 48, Figs. 18.) Compares the survival of caged weevils
with the appearance of weevils in a field, as determined by actual
counts, showing that the field count method is more accurate than
the cage method.







Forty-fifth Annual Report, 1981


234. The Two-Spotted Mite (Tetranychus telarius L.) on
Asparagus Plumosus. (J. W. Wilson, pp. 20, Figs. 6.) Outlines
the distribution of the pest, host plants, injury, seasonal history,
habits, and dispersion. Discusses climatic, natural, and artificial
control.
235. Crimp-A Nematode Disease of Strawberries. (A. N.
Brooks and R. E. Nolen, pp. 28, Figs. 5.) Reports experiments
which show that crimp is caused by a microscopic nematode.
Lists control measures.
236. Swine Production in Florida. (A. L. Shealy and W. J.
Sheely, pp. 60, Figs. 33.) Contains sections on breeds, caring for
the herd, feeding, slaughtering, marketing, and disease and para-
site control.
237. General Properties of Some Semi-Tropical Fruits of Flor-
ida. (0. D. Abbott, pp. 32, Figs. 5.) Describes the general pro-
perties, with particular reference to food value, of avocados, per-
simmons, papayas, citrus fruits, guavas, and mangoes.

PRESS BULLETINS

Fifteen new press bulletins were printed and 14 old ones were
reprinted during the year. Approximately 3,000 of each were
run at a printing. The list of press bulletins printed or reprinted
follows:
No. Title Author
427 Blackberries and Dewberries ........................Harold Mowry
428 Pumpkin Bugs in Citrus Groves .......................J. R. Watson
429 Spraying for Citrus Whitefly ......................... J. R. Watson
430 The San Jose Scale ..................................J. R. Watson
431 Gummosis and Psorosis of Citrus Trees............. Arthur S. Rhoads
432 Treatment of Gummosis and Psorosis of Citrus Trees, Arthur S. Rhoads
433 The Blakemore Strawberry ............. A. N. Brooks and R. E. Nolen
434 Poisoning Cotton Boll Weevils ............... Edgar F. Grossman
435 Powdery Mildew of Crape Myrtle .....................Erdman West
436 Orange Rust of Blackberries ........................Erdman West
437 Brown Patch of Lawns and Golf Greens and Its Control..Geo. F. Weber
438 Pear Blight and Its Control .........................Geo. F. Weber
439 Fig Rust and Its Control ...........................Geo. F. Weber
440 Formaldehyde Seed Treatment for Loose and Covered
Smuts of Oats .................................... A. H. Eddins
Bulletin List.
227 Bud-Worm, or Corn Ear-Worm (Reprint) ..............J. R. Watson
324 Gassing the Corn Weevil (Reprint) ................... J. R. Watson
327 How to Poison Ants (Reprint) ...................... J. R. Watson
338 Use Sulphur for Red Spiders (Reprint) ...............J. R. Watson
373 Spray Schedule for Peaches (Reprint), Carl B. James and J. R. Watson
384 Asparagus Plumosus (Reprint) ......................Harold Mowry
398 Crotalaria as a Soil Builder (Reprint), W. E. Stokes and W. A. Leukel
400 Preparation of Bordeaux Mixture (Reprint) ........... Geo. F. Weber
415 Plants Susceptible and Resistant to Root-Knot (Reprint) J. R. Watson






Florida Agricultural Experiment Station


416 The Control of Root-Knot in Seedbeds (Reprint) .......J. R. Watson
417 Foot-Rot of Citrus Trees and Its Treatment (Reprint)
Arthur S. Rhoads
420 Disinfectant Pastes and Washes for Treating Bark Dis-
eases of Citrus Trees (Reprint) .................Arthur S. Rhoads
421 The Cause and Control of Melanose (Reprint) ......Arthur S. Rhoads
422 The Cause and Control of Citrus Scab (Reprint) .... Arthur S. Rhoads

BULLETIN DISTRIBUTION
The distribution of bulletins to libraries, scientific workers, and
the public is handled in the mailing room, which is a part of the
editorial department. During the year approximately 75,000
copies of Experiment Station bulletins were distributed, most of
them to Florida farmers and farm women. Thousands of copies
of press bulletins were sent to news and farm papers and inter-
ested people.
To save expense, bulletins are not sent to a general mailing list.
A "notify" list is maintained, and when a new bulletin is issued,
a card announcing it is sent to this list. The bulletin is then sent
on special request in response to this card or otherwise.

NEWS STORIES
News stories and other forms of newspaper publicity were
largely used in carrying knowledge from Experiment Station
workers to the people of Florida. Hints are given as they become
timely, and new discoveries are announced from time to time.
The Agricultural News Service, issued and distributed weekly
by the Agricultural Extension Service, carried from three to six
or more stories each week about the Station and its workers,
either news or advice suggestions. These stories are largely re-
printed in the state newspapers.
Special stories to newspapers-particularly dailies-and farm
papers were sent from time to time. Also considerable informa-
tion was distributed to state dailies through the Associated Press
from copy furnished by this office.
Questions and answers about Florida farming subjects-the
questions coming from farmers and growers and many of the
answers being supplied by Station workers-were used weekly
in two state dailies and over the radio on WRUF; similar ques-
tions were used monthly by a Florida farm publication.
Two stories about the Station were supplied to the University
of Florida alumni magazine, one to a Southern farm paper, and
five to two Florida farm papers. The Editor conducted a page de-
voted to timely talks about farm work for the month in each of







Forty-fifth Annual Report, 1931


three different state farm papers. Many of the suggestions used
in these came from Experiment Station workers and were cred-
ited to them.

RADIO

Forty-five minute radio programs were put on the air over
WRUF each week day during the year. While this is an Exten-
sion activity of the Editors, Experiment Station workers were
called on for talks, and responded freely, making a total of 156
talks during the year, or an average of 13 a month. This afforded
them another opportunity of reaching Florida people with timely
and valuable information. Once each week from five to ten ques-
tions and answers were read as a part of the farm program, most
of the answers coming from Station workers.

SCIENTIFIC AND POPULAR ARTICLES
Among the articles contributed to scientific and other publica-
tions by Experiment Station workers during the fiscal year end-
ing June 30, 1931, were the following. Copy on these was not
handled by the Station Editors:

A New Diplodia Ear Rot of Corn--A. H. Eddins.
Phytopathology, Vol. 20, pages 733-742, 1930.
A New Plant Food for the Buckeye Butterfly-A. N. Tissot.
Florida Entomologist, Vol. XIV, No. 3, page 52, 1930.
A New Haplothrips from Panama-J. R. Watson.
Florida Entomologist, Vol. XV, No. 1, pages 11-12, 1931.
An Australian Tree for Florida-Harold Mowry.
Florida Grower, November, 1930.
Anthracnose of Strawberry Caused by Colletotrichum fragariae-A. N.
Brooks.
(Abst.) Phytopathology, Vol. 21, page 113, 1931.
Act Now and Have Fresh Vegetables-M. R. Ensign.
Florida Grower, February, 1931.
Biology of the Mexican Cotton Boll Weevil, V. Diurnal Observations of the
Emergence of Boll Weevils from Their Hibernation Quarters-E. F.
Grossman.
Florida Entomologist, Vol. XIV, No. 3, pages 45-52, 1930.
Biology of the Mexican Cotton Boll Weevil, VI. Some Humidity and Tem-
perature Effects on Development and Longevity-E. F. Grossman.
Florida Entomologist, Vol. XIV, No. 4, pages 66-71, 1930.
Bottom Rot of Cabbage Caused by Corticium vagum B. & C.-G. F. Weber.
(Abst.) Phytopathology, Vol. 21, page 117, 1931.
Brown Spot of Tobacco Caused by Alternaria longipes-W. B. Tisdale and
R. F. Wadkins.
Phytopathology, Vol. 21, pages 641-660, 1931.
By-Products of Dairy Research-R. B. Becker.
Proceedings of Association of Southern Agricultural Workers, Feb-
ruary, 1931.








Florida Agricultural Experiment Station


Cicadas Severely Damaging Asparagus plumosus-J. W. Wilson.
Florida Entomologist, Vol. XIV, No. 3, pages 41-44, 1930.
Composition of Florida Avocados-A. L. Stahl.
Proceedings of Florida State Horticultural Society, 1931.
Crimp, a Nematode Disease of Strawberries-A. N. Brooks.
(Abst.) Phytopathology, Vol. 21, page 113, 1931.
Crotalaria and Pumpkin Bugs-J. R. Watson.
Proceedings Florida State Horticultural Society, Vol. XLIII, pages
100-105, 1931.
Crotalaria as a Summer Cover Crop for Pecan Orchards-G. H. Blackmon.
Proceedings National Pecan Association, September, 1930.
Euvanessa Antiopa-The Mourning Cloak-H. E. Bratley.
Florida Entomologist, Vol. XV, No. 1, page 7, 1931.
Freezing the Juice of Tangerines-A. F. Camp.
Florida Grower, March, 1931.
Fumingation Research in Florida-A. F. Camp (co-author, R. J. Wilmot).
State Plant Board Monthly Bulletin, Vol. XV, Nos. 5, 6, 7, 8, 1930-31.
Grove Heating-A. F. Camp.
Proceedings Florida State Horticultural Society, October, 1930.
How to Grow Japanese Persimmons-Harold Mowry.
Florida Grower, December, 1930.
Influence of Inorganic Nitrogen Compounds on Reaction and Replaceable
Bases of Norfolk Sand-R. M. Barnette and J. B. Hester.
Soil Science, Vol. 30, pages 431-437, 1930.
Insect Enemies of the Cotton Boll Weevil-E. F. Grossman.
Florida Entomologist, Vol. XV, No. 1, pages 8-10, 1931.
Lightning Injury of Potatoes-G. F. Weber.
Phytopathology, Vol. 21, pages 213-218, 1931.
Observations on Certain Virus Diseases of Potatoes as Observed in Florida
and Maine-L. O. Gratz and E. S. Schultz.
American Potato Journal, Vol. 7, pages 187-200, 1930.
Ornamental Trees-Harold Mowry.
The Citrus Industry, November, 1930.
Ornamental Trees of Florida-Harold Mowry.
The Florida College Farmer, January, 1931.
Peanut Breeding-W. E. Stokes and F. H. Hull.
Journal of the American Society of Agronomy, Vol. 22, No. 12, De-
cember, 1930.
Pecan Growing in Florida-G. H. Blackmon.
Florida Grower, August, 1930.
Reduced Costs in Control of Aphids-W. L. Thompson.
Proceedings Florida State Horticultural Society, Vol. XLIII, pages
106-114, 1931.
Refrigeration Work in the Experiment Station-A. F. Camp.
Proceedings Florida State Horticultural Society, October, 1930.
Relation of Feed to Bone Strength in Cattle-R. B. Becker and W. M. Neal.
Proceedings American Society of Animal Production, 1930, pages
81-88.
Small Fruits-Harold Mowry.
Proceedings Florida Grape Growers' Association, July, 1930.
Some New Bases for Weather Forecasting-M. R. Ensign. (B. F. Dostal, co-
author.)
Proceedings Florida State Horticultural Society, 1931.
Some Phases of the Florida Citrus Situation-C. V. Noble.
Proceedings Florida State Horticultural Society, 1930, pages 115-122.








Forty-fifth Annual Report, 1931


Some Physiological Studies of Phytomon.s ritri-K. W. Loucks.
Journal Agricultural Research, Vol. 41, pages 247-258, 1930.
Tibicen davisi Smith and Grosbeck (Cicadidae), A New Pest of Economic
Importance-J. W. Wilson.
Floiida Entomologist, Vol. XIV, No. 4, pages 61-65, 1930.
The Mineral Analysis of a 19-Year-Old Marsh Seedless Grapefruit Tree-
R. M. Barnette, E. F. DeBusk, J. B. Hester and H. W. Jones.
The Citrus Industry, Vol. 12, No. 3, page 5, 1931.
The Tung-Oil Tree in Florida-Harold Mowry.
Proceedings Florida State Horticultural Society, October, 1930.
Time of Hatching 1 irst Generation Boll Weevils Relative to Appearance of
Blossoms-P. W. Calhoun.
Florida Entomologist, Vol. XIV, No. 4, pages 72-75, 1930.
Transmission of Spindle Tuber of Potatoes Through the Usual Commercial
Practices-L. O. Gratz and E. S. Schultz.
Proceedings of American Potato Association, page 17, 1930.
Tropical Agriculture and Research-Harold Mowry.
New York Herald-Tribune, July 6, 1930.
Tung Oil-Harold Mowry.
Proceedings of Association of Southern Agricultural Workers, Feb-
ruary, 1931.
Tung Oil Experiments-Harold Mowry.
The Tung Oil Magazine, December, 1930.
Why Our Crops Are Different-M. R. Ensign.
Florida Grower, July, 1930.
Winter Survival of Immature Stages of the Boll Weevil-E. F. Grossman.
Florida Entomologist, Vol. XV, No. 1, pages 13-14, 1931.






Florida Agricultural Experiment Station


REPORT OF THE LIBRARIAN
The fiscal year just ended has been the busiest one in the history
of the Library. With the addition of new projects and new
workers, the work of the Library has had to develop along new
lines also. The graduate students of the College of Agriculture
have carried on much of the work connected with the preparation
of their theses in the Library.
The question of space has been a serious one for some time.
Near the close of the fiscal year it was arranged for the Library
to take over an adjoining room, formerly used as an office, and
this has been converted into a reading room which will accom-
modate 30 persons. By releasing table room in the stack room,
four additional double-faced stacks have been erected which give
present relief from the congested condition of the shelves. It has
been possible to retain in the stack room small side tables which
are convenient for persons using considerable material from
the shelves.
The circulation of material to the workers stationed at the
branch and field laboratories has proved most satisfactory. It
has entailed a considerable amount of additional work and corre-
spondence, but has made it possible for the distant workers to
keep up with the literature relating to their projects. It has also
been most effective in bringing the distant workers into closer
contact with the Library so that they have felt free at all times
to call on it for assistance.
Routine work has been almost more than the present staff could
care for. It is necessary to have some one in constant attendance
at the charging desk and the shelf-work has increased accord-
ingly. The librarian and the cataloger have to attend to the cleri-
cal and stenographic work and keep the desk and shelves, except
as relieved by two student assistants who have worked for part
time in the Library this year. Under these conditions cataloging
and bibliographical work cannot keep up to date, although splen-
did progress has been made.
Through the medium of the inter-library loan hundreds of
references have been borrowed for the use of research workers,
when the reference was not available here. As usual the librarian
and staff of the Library of the United States Department of
Agriculture have rendered every possible assistance, as have also
the Library of Congress, the Library of the War Department, the
Cornell University Library, and others.






Forty-fifth Annual Report, 1931


With the impetus given Pan-American relations by the Institute
held here during the past fiscal year and the attendance at the
University of students from Pan-American countries, an in-
creased interest is being shown in the literature relating to the
agriculture and horticulture of the South American countries
and the island groups. Every effort is being made to secure all
available literature to cover these fields. The subject of tropical
and semi-tropical agriculture has been one that has held the
attention of the Library for some years, and its collection of
literature along these lines will continue to grow in importance.
An unprecedented number of bulletins, serials, periodicals and
continuations have been received for the year, totalling 15,226.
pieces. Since much of this has to be treated in the same way that
bound volumes are, the work in connection with caring for it has
been very heavy. During the year, 1,102 bound volumes have
been accessioned, making a total of 8,112 bound volumes, while
13,294 catalog cards, prepared and typed in the Library, have
been added to the card catalog. Material was assembled from
unbound bulletins, serials, etc., for 749 volumes and was sent to
the bindery for binding. These volumes are included in the total
number of accessions for the year. Forty-five volumes were pre-
pared and sent to the bindery for the various departments.
No articles have been published by the librarian as she is
devoting all available time to work on a history of the agriculture
of Florida. Two radio talks on "Rural Libraries for Florida"
were, however, published in The Florida Grower.






Florida Agricultural Experiment Station


AGRICULTURAL ECONOMICS

AGRICULTURAL SURVEY OF SOME 500 FARMS IN THE GENERAL
FARMING REGION OF NORTHWEST FLORIDA
Purnell Project No. 73 C. V. Noble, Leader

Work has again been halted on the interpretation of data from
the Jackson County area, for it has been decided that a represen-
tative sample survey of the original 500 farms should be taken
for another year. The original survey was made for the year
1925, a year of good financial returns for that area. A re-survey
was made for the year 1928 covering a sample of the first survey.
This was a year of low financial returns. Since there were such
great differences in the returns from individual enterprises for
the two years, the third survey seems essential before definite
recommendations are made as to the most profitable type or types
of farm organization for this area over a period of years.

AN ECONOMIC STUDY OF DAIRY FARMING IN FLORIDA
Purnell Project No. 104 Bruce McKinley, Leader
The analysis of the data covering the 249 Florida dairy farms
has continued throughout the year. In addition to the specific
measures used in studying the data, and mentioned in the last
annual report, some of the new methods of attack have been:
1. Comparisons of dairies selling milk wholesale with those
retailing their milk, principally as to: (a) Costs of production
per hundredweight; (b) labor income of the operators; (c) milk
production per cow; (d) size of dairy, measured by number of
cows; and (e) man-labor requirements.
2. Relation of labor efficiently to milk production, size of herd
and other factors.
3. Relation of feed costs per cow to the total cost of producing
milk, labor income and other factors.
4. The breeds of cows used.
5. The ages of cows kept in the herds.
6. The methods and the rate of replacement of dairy cows, in-
volving the purchase, sale and death rate of cows and the replace-
ment by home raised heifers.
7. Some factors indirectly connected with the dairy have also
been studied, such as: (a) Operator's business history; (b) age
of operator; (c) relation of education of operator to labor income






Forty-fifth Annual Report, 1931


received; (d) "cost of operating automobiles, trucks and tractors
on these dairy farms; (e) use of fertilizers on these dairy farms;
and (f) value of home products furnished the operators.
The manuscript has been prepared and has passed through
several revisions.

A STUDY OF FLORIDA TRUCK CROP COMPETITION
Purnell Project No. 123 C. V. Noble and M. A. Brooker,
Leaders
As stated in the last annual report, this study was divided into
the two parts:
Florida Truck Crop Competition I. Inter-State and Foreign.
Florida Truck Crop Competition II. Intra-State.
The first mentioned study is now being printed and will soon
appear as Bulletin 224. It was possible to include data covering
the 1929-1930 season before this study went to press.
The Intra-State study is in manuscript form and it is.the hope
that it will soon be sent to the printer.

FARMERS' COOPERATIVE ASSOCIATIONS IN FLORIDA
Purnell Project No. 154 H. G. Hamilton, Leader
At the beginning, of the fiscal year complete data on 45 and
part data on 25 cooperative associations had been obtained. This
year the data were completed on the 25 incompleted records and
complete data were secured on 311 other cooperative associations.
Data covering the principal operations, where available, have now
been practically completed on 381 cooperative associations. These
associations have been grouped according to principal commodi-
ties handled. The number of associations in each group together
with the date organized are shown in Table I. Perhaps not more
than 50 per cent of these associations are active at the present
time.







32 Florida Agricultural Experiment Station

*
TABLE I.-NUMBER AND KIND OF COOPERATIVE ASSOCIATIONS ORGANIZED IN
FLORIDA EACH YEAR THROUGH THE 1929-30 SEASON

Year Livestock Percent
Organ- Citrus & Livestock Truck Subsidi- Miscel- Total of
ized Products Crops aries laneous Total
1889 1 .... .... 1 .3
1892 1 .... .. .. 1 .3
1894 1 .. .. 1 .3
1899 .. .1 1 .3
1909 97 .. 97 25.4
1910 6 .. .. 7 1.8
1911 1 1 .3
1912 5 .. 1 .. 1 7 1.8
1913 1 .. 2 .. 1 4 1.0
1914 7 .. 1 .. 3 11 2.9
1915 11 .. 4 .. 2 17 4.5
1916 5 .. 2 2 1 10 2.6
1917 3 .. 2 .. .. 5 1.3
1918 3 10 .. .13 3.4
1919 4 1 3 .. 3 11 2.9
1920 8 .2 .. 2 12 3.1
1921 4 1 5 .. 1 11 2.9
1922 1 2 4 1 .. 8 2.1
1923 3 1 11 .. 2 17 4.5
1924 22 1 4 1 2 30 7.9
1925 2 1 2 2 1 8 2.1
1926 3 6 7 1 1 18 4.7
1927 1 6 11 2 5 25 6.5
1928 2 3 8 .. 3 16 4.2
1929 4 3 12 4 9 32 8.4
*1930 3 5 6 1 2 17 4.5
Total 199 30. 99 14 39 381 100.0

*Twelve of these organized too late to operate during the 1929-30 season.

The data secured on each of these associations have been
transferred to a work sheet. Factors of efficiency have been com-
puted for each of the cooperative associations.






Forty-fifth Annual Report, 1931


AGRONOMY
During the year agronomy experimental work progressed
satisfactorily with very few changes.
The Forage Crops Office of the United States Department of
Agriculture installed an Arnold drier for studies on the artificial
curing of Crotalaria and other hay crops. A head house and
Arcola heating plant was added to the agronomy-chemistry
greenhouse. A combine was loaned to the department by the
Caterpillar Tractor Company for use in experiments looking to
the harvesting of Crotalaria seed by machinery.
Agronomy phases of cotton investigations formerly handled
by the Cotton Department were transferred to the Department of
Agronomy December 4, 1930, and most of the cotton experimental
work was placed at the Quincy Station this spring.
Two new projects were started during the year: (1), a study of
.Crotalaria as a forage crop, in cooperation with the Forage
Crops Office, USDA, and (2) mutations induced by heating seed
corn, in cooperation with the Cotton Department.
About 7,000 pounds of Crotalaria spectabilis seed were saved
and sold to farmers of the state. The seed were distributed by the
Agricultural Extension Service.

CROP ADAPTATION STUDIES*
Hatch Project No. 107 Geo. E. Ritchey, Leader
Introduction Garden
There were 411 plantings of different kinds of plants made in
Gainesville during the season of 1930 and 1931. They were classi-
fied as follows: Pigeon peas, 30; Crotalaria, 87; grasses, 75;
miscellaneous, 125; and winter crops, 94.
One hundred of the former pigeon pea introductions were dis-
carded on the basis of non-seeding, scanty foliage, and nematode
injury. There are indications that at least some varieties are
resistant to nematode. A selection of Bahia grass made by F. H.
Hull showed signs of being resistant to Helminthosporium dis-
ease and these are being propagated in the advanced plots.

Advanced Work
In an attempt to find a use for some of the promising pigeon
peas one acre was fenced and cattle were grazed on them. The


*In cooperation with Forage Crop Office, USDA.






Florida Agricultural Experiment Station


cattle did not show a liking for them. This is being repeated this
summer.
An acre of Crotalaria striata also was fenced and cattle were
turned into the lot. The cattle refused to eat the Crotalaria. This
test is being continued with eight other species growing in the
same pasture.
Plants showing special promise are being propagated in larger
plats with a view of obtaining planting material for field tests.
A garden similar to the garden at Gainesville, except on a
somewhat smaller scale, has been planted at the Quincy Station,
and another at the Belle Glade Station, to give the plants a test
under the conditions at those places.

VARIETY TEST WORK WITH FIELD CROPS*
Hatch Project No. 56 G. E. Ritchey and W. E. Stokes, Leaders
Cowpea Date of Planting and Variety Test
Eight varieties of cowpeas were run in a date of planting test.
These included the Black Eye, Blue Goose, Brabham, Brown Eye,
Black Crowder, Conk, Florida Clay and Iron.
The Conk gave the heaviest yields when planted in March. All
others gave higher yields when planted in April. The highest
total yields were obtained from the Conk in the March and June
plantings and from the Brabham in the April and May plantings.
The Iron variety stood third in rank in yield.
Thirteen varieties are being used in the test in 1931.
Soybean Date of Planting and Variety Test
The Biloxi, Laredo, Mammoth Yellow and Otootan varieties
of soybeans, also an unnamed variety bearing S.P.I. number 72049
were used in the test. They were planted the first of each month
from February to May. The highest yields of the Laredo, Mam-
moth Yellow and Number 72049 were obtained from the April
planting. The Biloxi gave the highest yields from the plots planted
in March while the plots of Otootan planted in February and
March gave the highest yields, there being little difference in the
yields of the two months.
The same varieties are included in the same test in 1931.
Sorghum and Millet Tests
In this test sorghum (Early Amber), Pearl millet and German
millet were used. The plats were divided and a portion was
*In cooperation with Forage Crop Office, USDA.






Forty-fifth Annual Report, 1931


clipped three times during the summer, another portion was cut
twice, and the remainder was cut at the end of the season.
Of these, Pearl millet cut three times during the season yielded
highest-25,657 pounds green weight per acre. The German
millets gave the lightest yields. The Pearl millet seemed to give
higher yield when cut more often, while the sorghums made heav-
ier yields when cut only once during the season.
The experiment is being continued during the season of 1931
with six additional crops being added.

Cooperative Corn Variety Tests
The results of all corn variety tests conducted by the Florida
Experiment Station are summarized each season and the most
promising varieties are selected for further tests in cooperation
with farmers in various counties in Central and Northwest
Florida. Twelve of these tests located in 10 counties are in
progress.
This procedure places the varieties under a wide range of soil
and moisture conditions, therefore the results obtained should
give some indication of the best "general purpose" corn for the
state.
In addition to the above variety test work the following crops
were in variety tests: Peanuts, oats, rye, and sugarcane.

PASTURE EXPERIMENTS*
Hatch Project No. 27 G. E. Ritchey and W. E. Stokes, Leaders
During the last year the following pasture studies have been
in progress: I. Competitive studies. II. The influence of ferti-
lizers on yield and composition of grasses. III. The influence of
frequency of mowings on yield and composition of grasses. IV.
The carrying capacity of pasture. V. The influence of various
fertilizer formulas on the yield of pasture. VI. Comparison of
native and improved pastures, comparison of burned and un-
burned native pastures, and comparison of methods of land prep-
aration previous to seeding improved pasture plants. This last
phase is being conducted in cooperation with the Animal Hus-
bandry Department and the Penney-Gwinn Corporation on 770
acres of the corporation's land under lease to the State Board of
Education.


*In cooperation with Forage Crop Office, USDA.






Florida Agricultural Experiment Station


I.-Competitive Studies
There has been little change in the sod since the last report.
The experiment is being continued, however, and observations are
being made.

II.-The Influence of Fertilizers on Yield and Composition of Grasses
This experiment has been continued as previously planned;
namely, Bahia grass, carpet grass and centipede grass plats were
treated with ammonium sulfate at the rate of 250 pounds per
acre and others with a 9-7-5 fertilizer at a rate which furnished
an equivalent amount of nitrogen. Each plat is adjacent to a
check plat which received no treatment. The experiment was
duplicated on two types of soil, namely fine Norfolk sandy soil
and a gravelly phase of Norfolk soil.
The results are similar to those of 1929 except that in all three
grasses the gravelly phase of Norfolk soil seems to have produced
the heaviest yields. There, seems.to be very little if any difference
between the yields of the plats treated with ammonium sulfate
and those treated with the complete fertilizer. There is how-
ever a substantial increase in the yields of the fertilized over the
unfertilized plats, the increase varying from about 25 to 100%.
This experiment is being continued in 1931.

III.-The Influence of Frequency of Mowing on Yield and Composition
of Grasses
Duplicated plats fertilized with ammonium sulfate at the rate
of 250 pounds per acre were mowed at 10-, 20- and 30-day inter-
vals. Each plat was accompanied by a check which was mowed
at the same interval but was given no fertilizer treatment. Table
II gives the results which indicate that except in the carpet grass
there was little if any difference in the yield of the plats of the
same grass mowed at different intervals. The carpet grass mowed
at 30-day intervals seems to have produced the higher yields.
There does, however, seem to be a higher percentage of nitrogen
in the grasses mowed every 10 days over those at 20- and 30-day
intervals. The data indicate that the more frequent mowings
supply a product richer in nitrogen and probably a greater amount
of total protein than those mowed less frequently. The difference,
however, is so slight that it is doubtful if it is significant.
The experiment is being continued during 1931.







Forty-fifth Annual Report, 1931


TABLE II.-GRASS CUTTINGS FROM INTRODUCTION GARDEN, NORFOLK MEDIUM
SAND. AVERAGE OF TWO PLATS FOR SEASON 1930. FERTILIZED WITH
AMMONIUM SULPHATE AT RATE OF 150 POUNDS PER ACRE IN
THREE APPLICATIONS. CHECKS NOT FERTILIZED.

Gain over Check
Interval Dry Weight % Nitrogen Nitrogen Lbs. Lbs.
of Lbs. per acre average Lbs. per acre per Ave. N
Grass cutting -- -- -- acre % par
(Days) Fert. Check Fert. Check Fert. Checkdrywt. N. acre

Bahia.... 10 1,579 1,293 2.09 2.12 33.5 27.3 286 -.03 5.2

Bahia.... 20 1,559 1,301 1.73 1.93 26.1 25.0 258 -.19 1.1

Bahia.... 30 1,523 1,234 1.66 1.71 24.5 18.2 289 -.05 6.3

Carpet... 10 934 801 2.12 1.88 20.4 15.5 133 .24 4.9

Carpet... 20 1,020 820 1.97 1.91 20.5 15.8 200 .06 4.7

Carpet... 30 1,119 809 1.64 1.62 18.2 12.7 310 .02 5.5

Centipede 10 697 404 1.35 1.28 9.5 5.1 293 .07 4.4

Centipede 20 754 269 1.23 1.19 9.0 3.0 485 .04 6.0

Centipede 30 690 537 1.29 1.19 8.9 6.5 153 .10 2.4

*Calculated from each cutting and its analysis.

IV.-The Carrying Capacity of Pastures Planted to Different Sorts of Grasses
The grazing experiment did not give as gratifying results as
were hoped for. The poor results no doubt were due to abnormal
weather conditions, a poor grade of steers, and to the fact that
the cattle had to be dipped every two weeks.
Each 31/2-acre pasture was grazed by four steers in 1930 in-
stead of five as in 1929. The centipede pasture which was not
used in 1929 was used in 1930. The cattle were placed on the
pasture March 23 and removed November 14.
Table III gives the 1930 results of the test. It will be noted
that cattle on the centipede pasture made much the best gains,
with Bermuda ranking second and the mixture and carpet giving
the least gains.







Florida Agricultural Experiment Station


TABLE III.-RESULTS OF GRAZING TESTS WITH BEEF CATTLE ON VARIOUS
PASTURE GRASSES AT THE FLORIDA EXPERIMENT STATION, 1930.
(IN COOPERATION WITH ANIMAL HUSBANDRY DEPARTMENT)

Average Average Pounds Average Total
initial daily of beef live wt. gain of
Pasture weight gain per produced gain per 4 steers
of steer per steer for on pasture
steers pounds acre season 235 days

Bahia........... 569 .423 113.7 99.5 398

Bermuda........ 571 .485 130.5 114.2 457

Carpet.......... 552 .212 57.1 50.0 200

Centipede....... 526 .636 170.8 149.5 598

Mixture.......... 601 .202 54.2 47.5 190

NOTES: Pastures 3.5 acres each grazed 4 steers per pasture. Each pas-
ture fertilized twice with nitrate of soda-50 pounds per acre each time.
Steers were put on pasture March 23; taken off November 14. Average gain
per steer for entire lot of 20 was 92.1 pounds each. Land rent, $4.00 per acre.
Fertilizer cost, $3.50 per acre. Average return per acre, after deducting fer-
tilizers and rent charges, showed a loss of 17 cents.

The experiment is being continued during 1931, using four
steers (two grade Angus and two scrubs) on each pasture. To
June 30, 1931, the cattle on the Bermuda pasture are showing the
greatest gains with those on the centipede following closely.

V.-The Influence of Various Fertilizer Formulas on the Yields of Pasture
This experiment which was outlined in the spring of 1930 was
laid out on a plat of Bahia grass. The experiment comprises 21
fertilizer formulas varying in the plant food constituents. The
plats were mowed each month and yields taken.
Only one year's results have been obtained but these yields
indicate that nitrogen is the limiting factor; also that phosphate
in connection with nitrogen is essential in producing the maxi-
mum yields.







Forty-fifth Annual Report, 1931


VI.-Comparison of Native and Improved Pastures, Comparison of Burned
and Unburned Native Pastures, and Comparison of Methods of Land
Preparation Previous to Seeding Improved Pasture Plants
The improved pastures (seeded to carpet, Dallis, Bahia and
lespedeza) gave better gains than the native pastures.
Burned native pastures gave better gains than unburned native
pastures.
Double disking gave a better stand and growth of grasses than
single disking. Single disking the land gave a better stand and
growth of grasses than seeding behind a burn with no disking;
and, seeding behind a burn gave a better stand and growth than
seeding in the rough.

FERTILIZATION OF PASTURE GRASSES
Hatch Project No. 120 W. A. Leukel, Leader
As previously reported, the higher ash content in Bahia, centi-
pede and carpet grasses kept in a growing vegetative condition
in comparison with such grasses grown to maturity indicated a
higher mineral content. This surmise was substantiated by
mineral analyses. Grasses kept in a vegetative growth condition
through fertilization, cutting and irrigation showed a higher
percentage of calcium, magnesium, phosphorus and potassium
than such grasses in a more mature growth condition. Plants
not cut frequently even when fertilized showed a gradual decrease
in mineral percentage as they approached the more mature growth
stages.
Nitrate Accumulations in Pasture Grasses
The different forms of nitrogen including nitrates in the top
growth of Bahia grass when fertilized heavily with nitrate of
soda showed no marked difference from similar compounds in the
top growth of grasses not so treated.
Bahia grass plants grown under greenhouse conditions in soils
with different moisture contents thus far show little variation in
nitrates when fertilized with nitrate of soda. Increased nitrogen
available appears to be reflected in increased growth and not in
accumulation of nitrates in the plants.

LYSIMETER STUDIES ON PASTURE GRASSES
Hatch Project No. 158 W. A. Leukel, Leader
As previously reported, grasses grown in lysimeters and fer-
tilized showed a downward trend in percentage of nitrogen from
the different cutting treatments in the following order: cut fre-






Florida Agricultural Experiment Station


quently, less frequently, cut in seed stage, and not cut. Analyses
for phosphorus and potassium show a similar variation.
The quantity of nitrates in the leachings collected from these
lysimeters at intervals during the growing season was in the
reverse order. This phase is being conducted in cooperation with
the Chemistry Department.

GROWTH BEHAVIOR OF BAHIA GRASS
Hatch Project No. 100 W. A. Leukel, Leader

The study of root growth behavior of Bahia grass was under-
taken in addition to results previously reported. A large, vigorous
root growth was produced by plants during the more mature
growth stages. Plants cut frequently produced a more fibrous
and less extensive root growth. The latter plants retained a more
constant root growth from fall to spring. Plants grown to matu-
rity during the summer showed a slight decrease in root weight
from fall to spring. A further study of root growth behavior is
being made by observing their growth in a large soil container
with glass on one side. Soil temperature records are being taken
and compared with actual soil temperatures. Thus far observa-
tions show prospects for interesting results.
A study of the deposition and utilization of mineral compounds
in pasture grasses is to be undertaken in connection with this
work.

SOURCES OF NITROGEN AND RATES OF APPLICATION OF
NITROGEN AS TOP-DRESSING FOR OATS
State Project No. 97 W. E. Stokes and J. D. Warner, Leaders

In the sources of nitrogen test, nitrate of soda again proved
the most satisfactory source of nitrogen as a top-dressing for
oats, with calcium nitrate a close second.
In the rates of nitrogen tests using nitrate of soda as a top-
dressing for oats the tests at Gainesville show that 100 pounds per
acre gave the most profitable returns per dollar invested, while
the 300 pound per acre rate gave the greatest total yield of oats
and also the greatest total yield of oats and straw combined.
Results of experiments conducted in Leon and Jackson counties
on Orangeburg sandy loam soils show that oats and rye respond
in a marked degree to applications of nitrate of soda. This will
be noted in Table IV.
It will be noted that the Fulghum variety of oats produced







Forty-fifth Annual Report, 1931


more seed than the Appler variety, but the Appler variety pro-
duced more straw.
Hastings Blue Stem wheat and Tennessee Beardless barley have
proven failures from the standpoint of seed production for the
past two seasons. These crops are very susceptible to attacks of
rust which causes loss of foliage and shriveled seeds.

TABLE IV.-RESULTS OF TOP-DRESSING SMALL GRAINS WITH NITRATE OF
SODA, 1930-31.

Fulghum Oats Appler Oats Abruzzi Rye Blue Stem Wheat

Treatment Wt. in Bushels Wt. in Bushels Wt. in Bushels Wt. in Bushels
Sheaf per Sheaf per Sheaf per Sheaf per
per acre per acre per acre per acre
acre acre acre acre

No top-dressing....... 1,237 14.4 1,597 12.0 2,462 7.0 1,123 1.9

50 lbs. nitrate of soda.. 2,352 29.7 2,904 18.2 3,778 9.1 1,456 2.0

100 lbs. nitrate of soda. 3,598 46.0 4,574 30.0 4,743 11.6 1,676 1.5

150 lbs. nitrate of soda. 4,016 49.1 5,372 32.3 4,418 11.5 1,878 3.1
150 lbs. nitrate of soda.
50 lbs. muriate potash.. 3,973 48.6 5,953 38.7 4,456 10.5 1,909 3.3

200 lbs. nitrate of soda. 4,108 52.5 5,881 37.4 5,479 13.6 2,290 3.7


MUTATIONS INDUCED BY HEATING SEED CORN
State Project No. 176 E. F. Grossman, Leader
Work under this project has been conducted cooperatively by
the Cotton and Agronomy departments.
Three varieties of corn (Zea mays) were subjected to heat
treatment extending from 560 to 800 C. in temperature and from
5 to 360 minute periods of time. Germination tests showed that
some treated seed could withstand an exposure to 800 C. for 10
minutes, 790 C. for 15 minutes, and corresponding exposures for
lower temperatures until at 560 C. a treatment for 360 minutes
did not affect germination. Treated seed planted in the field
yielded 93 plants which showed a striping similar to the heredi-
tary type known as japonica. Extended tests in flats kept in a
greenhouse yielded many striped plants. The striping was largely







Florida Agricultural Experiment Station


confined to plants grown from seed treated at the higher tempera-
tures, namely, 700 C. to 830 C. The striping is probably cyto-
plasmic, consisting of the destruction or inactivation of the
chloroplasts.

IMPROVEMENT OF CORN THROUGH SELECTION AND BREEDING
Puinell Project No. 105 F. H. Hull, Leader
Selection within self-fertilized lines and their recombination:
This work is now in the fifth year. The 1931 planting consists
of 1,500 inbred ear-rows representing approximately 500 inbred
lines. These are planted in duplicate. Self-pollination and selec-
tion are being continued this season. Combination of inbreds for
testing their hybrid progeny will not be begun until 1932.
Corn Breeding by the Ear-row Method: The combinations from
the Tisdale and Wilson ear-row tests are included in the 1931
yield test. An ear-row test with Whatley Prolific is being run
this year at Gainesville, Quincy and Belle Glade. This variety
has been one of the best in previous variety tests. The main points
of selection are to be long, tight husks, hard kernels, low weevil
infestation and good yield.
Sweet Corn Breeding: The aim in this work is to produce
sweet corn which is in other respects similar to our best white
dent roasting ear varieties. The method used is a system of
backcrossing or outcrossing. The first crosses were made in 1928.
In 1931 second generation hybrids which were sweet were out-
crossed or backcrossed to good type roasting ear varieties. The
sweet corn segregating from these crosses will be pure sweet but
will carry "75% of blood" of corn which has proven to be good
roasting ear type in Florida. It is not possible to tell how many
more crosses need be made to the adapted type of roasting ear
corn. The sweet corn thus produced may be used directly for
commercial growing. It may also serve as foundation stock for
further work in sweet corn breeding by more specialized methods.
Yield Tests: The 1931 yield test is combined with Project No.
106. It includes 25 different plantings at five different dates.
Records are to be taken on yield of grain, roasting ears and silage,
and on a number of the more important characteristics of the
varieties. The report on previous yield tests is found under
Project No. 56 summarized with other yield tests from various
parts of the state.
General: Records of soil and air temperatures, relative humid-
ity, precipitation and solar radiation are being continued.







Forty-fifth Annual Report, 1931


EFFECT OF TIME OF PLANTING CORN ON FORAGE AND GRAIN
YIELD
State Project No. 106 W. E. Stokes and J. P. Camp, Leaders
In the date of planting test of corn two varieties are used, Early
Yellow Dent and Florida Flint. The 1930 crop from plantings the
15th of February, March, April, May and June, show the highest
yield of silage from the March planting of both varieties while
for yield of corn the March planting of the Early Yellow Dent
and the February planting of the Florida Flint show highest
yields.
For 1931 planting season 25 different corns are in the date of
planting test.
CORN FERTILIZER EXPERIMENTS
State Project No. 163 J. D. Warner, Leader
The results of the six experiments conducted in Central and
Northwest Florida during 1930 show that the response of corn
to applications of nitrogen, phosphorus and potash varied with
the soil type and moisture conditions. Nitrogen proved to be the
most deficient element in most of the soils under investigation.
However, on Tifton soils nitrogen did not stimulate yields in the
absence of potash while on still other soil types the growth and
yield of corn did not respond to any fertilizer treatment.
Two additional experiments were started in 1931, making a
total of eight experiments covering eight soil types in Central
and Northwest Florida. As these experiments increase in age
sufficiently to establish a rating of the various fertilizer treat-
ments, other soil types will be studied.
Sources of Nitrogen for Side-Dressing
Five sources of nitrogen are in comparative tests in coopera-
tion with farmers in Leon, Gadsden and Washington counties.
Nitrogen from each source was applied at the rate of 16 and 32
pounds per acre on triplicate 1/20-acre plots when the corn was
from 35 to 45 days old. Results from these tests should give some
indication of the most efficient source of nitrogen for side-dress-
ing corn in Northwest Florida.
PEANUT AND CORN FERTILIZER EXPERIMENTS
Hatch Project No. 16 W. E. Stokes and J. P. Camp, Leaders
This project was continued with the results showing that, on
Norfolk deep sandy land at Gainesville, no kind or amount of
fertilizer used paid a profit on Spanish peanuts.







Florida Agricultural Experiment Station


The corn sources of nitrogen fertilizer experimental work be-
ing conducted on deep phase Norfolk sandy land at Gainesville
using cottonseed meal, nitrate of soda, sulfate of ammonia, leuna-
salpeter, calurea, urea, compohumus and calcium nitrate as
sources of nitrogen with and without phosphate and potash shows
that nitrogen alone on this type of soil usually pays more profit
on field corn than does a complete fertilizer. Phosphate and
potash in connection with the various sources of nitrogen in some
instances gave slightly higher yields of corn than where only
nitrogen was used, but in most instances this increase was not
enough to be profitable.
Organic sources of nitrogen used were not profitable on field
corn grown on the type of soil being used in this experiment.

EFFECT OF POTASH ON YIELD AND QUALITY OF SPANISH
PEANUTS
State Project No. 138
W. E. Stokes, W. A. Leukel and J. P. Camp, Leaders

This project in which 35 formulas with phosphoric acid con-
stant at 10 percent and varying in percentage of potassium
(K20) from 0 to 16 and percentage of nitrogen from 3 to 6 is
still being conducted. The yield of peanuts from the variously
treated plots has varied considerably. In some cases a treatment
would appear to increase the peanut yield five to eight bushels
per acre over that of no treatment, but in no case did the increase
in yield pay a profit over the cost of the fertilizers. One phase of
this project is being conducted in the Spanish peanut area of
Jackson County in 1931. This has to do with varying the potash
from 0 to 12 percent by 4 percent increments, while the nitrogen
and phosphorus are held constant at 3 and 10 percent, respec-
tively.
Laboratory analyses were made on peanuts grown under differ-
ent fertilizer treatments, namely, 5-10-12, 3-10-2, 3-10-0 and no
fertilizer treatment. Little variation was shown in composition
in regard to carbohydrate, protein or oil content of these differ-
ently treated peanuts. Some variation was shown in the refrac-
tive index of the oil from the differently treated nuts but the
acidity and the iodine number or the Reichert Meissl number
were quite uniform. Peanut plants receiving higher applications
of potash appeared to produce a better grade of nuts than plants
not so treated.







Forty-fifth Annual Report, 1931


EFFECT OF LANDPLASTER OR GYPSUM ON HAY AND SEED
PRODUCTION OF PEANUT VARIETIES
Hatch Project No. 43 W. E. Stokes and J. P. Camp, Leaders
On the old test area where landplaster (CaSO4. 2H0O) has been
used on peanut varieties on the same land for a number of years
the increase in yield of seed peanuts due to landplaster is now
very slight, whereas landplaster on peanuts on land not pre-
viously landplastered gave profitable increases in yield with Flor-
ida Runner and Jumbo peanuts but not with Spanish, Valencia,
and Virginia bunch peanuts.

PLANT BREEDING-PEANUTS
Hatch Project No. 20 F. H. Hull, Leader
Breeding by Selection: The seven selected strains of Spanish
peanuts mentioned in last year's report are being further tested
and the supply of seed is being increased for distribution.
Breeding by Hybridization and Selection: This work is being
continued as previously outlined. About 40 hybrid progenies are
growing under observation in 1931. A new introduction from
Brazil, probably Arachis prostrata, has been added to our collec-
tion, and is growing under observation.

RATIO OF ORGANIC TO INORGANIC NITROGEN IN MIXED
FERTILIZER FOR COTTON
State Project No. 159 J. D. Warner, Leader
During the 1930 season four widely separated tests were car-
ried to completion. The results for the one season indicate that
inorganic nitrogen was slightly more efficient than organic nitro-
gen in stimulating yield. However, it is likely that the extremely
dry season on three of the experiments obscured any differences
that normally would have occurred.
Experiments now in progress at the Main Station, the Quincy
Station, and in cooperation with J. C. Smith, farmer in Walton
County, should throw more light on the comparative efficiency
of the two forms of nitrogen.

WINTER LEGUME STUDIES*
Hatch Project No. 53 Geo. E. Ritchey, Leader
This project includes the following lines of studies: I. Date
of turning of winter peas and vetch. II. Date of planting winter

*In cooperation with Forage Crop Office, USDA.






Florida Agricultural Experiment Station


peas and vetch. III. Crop rotation systems using vetch. IV.
Rate of seeding winter peas and vetch. V. Superphosphate fer-
tilizer studies. VI. Preliminary cover crop field plat tests.
The field upon which the first five experiments are located is
badly infested with nematode and rhizoctonia so that a light crop
of vetches and peas was realized in both 1930 and 1931. Yields of
corn following the cover crops were taken and as only one year's
results have been obtained no reliable data are available. The
results, however, indicate that even though the yield of cover crops
is low an increase in production of the following crop may be
expected.
VI.-Preliminary Cover Crop Field Plat Tests
Sixteen of the winter cover crops which haa shown up well in
the introduction garden in 1929 and 1930 were planted in small
field plats in the autumn of 1930. Yields were taken in the spring
of 1931. Of these the heaviest yields were made by the imported
hairy vetch and the tangier pea. The tangier pea yielded over 8
tons of green material per acre and produced a considerable
amount of seed. It is a promising crop for the light sandy soils.
Plantings will be made next fall to give it further trial.

DATE OF SEEDING AND PHOSPHATE REQUIREMENTS OF WINTER
LEGUMES AND THEIR EFFECT UPON SUBSEQUENT CROPS
State Project No. 153 J. D. Warner, Leader

This project is being continued as outlined in previous reports.
Whole-hearted support from county agents and farmers during
the last year have made possible further study of the response of
winter legumes to phosphate on the principal soil types of Central
and Northwest Florida. Seventeen tests embracing 427 plots
which occupy 35 acres of land were carried to completion so far
as the cover crops are concerned. In most cases these crops are
being followed by corn, the yields to be taken as a measure of the
value of the cover crops.
The data for the past season serve to strengthen those of the
previous year in that the response of Austrian winter peas,
Monantha vetch and hairy vetch to phosphate ranged from slight
to a very marked increase in growth, depending on soil type and
fertilization of previous crops.
The yield of corn following the winter cover crops of 1930 was
in some cases twice as much as where no cover crops were turned
under and in all tests a consistent marked increase was noted.






Forty-fifth Annual Report, 1931


Seedings of cover crops made during the month of October
gave the earliest and most satisfactory growth.

SUMMER COVER CROP STUDIES*
Hatch Project No. 54 Geo. E. Ritchey, Leader

Crotalaria grantiana, C. incana, C. intermedia and C. lanceo-
lata were planted in rows in the field to determine their behavior
under the field conditions with a view of determining their value
as a cover crop and also to test their seeding qualities. The
Crotalaria intermedia and C. lanceolata both produced good
growth and seeded well. The seed was picked and saved. The
C. grantiana seeds well but the pods adhere without dehiscing
readily, making it possible to harvest and thresh. The growth of
C. grantiana was good. The Crotalaria incana failed to produce
seed and the growth was unsatisfactory.

A STUDY OF CROTALARIA AS A FORAGE CROP**
State Project No. 174 Geo. E. Ritchey, Leader

The object of the project is to determine whether or not it is
possible to use profitably any of the species of Crotalaria as forage.
An Arnold hay drier has been purchased by the Bureau of
Plant Industry, and is installed near the Crotalaria fields. The
drier will be used in drying several crops, in making cost account
studies, and other records will be kept to determine as nearly as
possible the cost of drying efficiency of the machine in hay pro-
duction and quality of hay produced by it.
About 15 acres has been sown to different Crotalaria species
which will be cut and run through the drier the coming summer.
The hay thus produced will be used in a cattle feeding experiment
by the Animal Husbandry Department. The hay will be com-
pared with standard alfalfa hay.
*In cooperation with Forage Crop Office, USDA.
**In cooperation with Bureau of Plant Industry, USDA.






Florida Agricultural Experiment Station


ANIMAL HUSBANDRY

DAIRY HERD MANAGEMENT
Tick eradication in this area was completed under federal super-
vision, and it is anticipated that if no reinfestation occurs, federal
quarantine on the movement of cattle will be removed probably
about December 1, 1931, on the Experiment Station farm in
Alachua County. Milk records are being tabulated to determine
the slight effect of dipping upon milk production. The herd con-
tinues to be federal accredited as free from tuberculosis. Agglu-
tination tests are being applied regularly in maintaining the herd
free from contagious abortion.


Fig. 1.-Dipping vat on the Experiment


-S n gr

Station grounds.


Herd sires are continuing to be proved through official produc-
tion records, in cooperation with the breed associations. The
following Register of Merit and Advanced Registry records were
completed during the year:
Majesty's Creole's Sue 491753-9 yr. 1 mo..... 8,564 4.84% 414.82 lbs. fat
Lasifoso's University Belle 572518-7 yr. 2 mo.. 9,292 4.45% 413.70 lbs. fat*
Sophie's Majesty's Heiress F 715637-3 yr. 6 mo. 8,526 -5.58% 475.73 lbs. fat
Majesty's Sophy's Pogis 744139-2 yr. 11 mo.... 6,234 5.87% 365.87 lbs. fat
*Subject to final checking by American Jersey Cattle Club.







Forty-fifth Annual Report, 1931


Sophy's Noble Queen Ann 768051-2 yr. 10 mo.. 7,878 4.91% 386.59 lbs. fat
Sophy's Fontaine Mary 768053-2 yr. 4 mo.... 6,344 5.23% 331.96 lbs. fat
Wexford Majesty Heiress 768054-2 yr. 2 mo... 6,398 5.08% 325.23 lbs. fat
Florida's Majesty Noble Lass 792758-2 yr. Imo. 6,594 4.96% 327.19 lbs. fat
Renie of Rock Springs 130035-mature........ 9,920 4.35% 432.0 lbs. fat

All cows were milked twice daily.
Herd records are being assembled for important studies with
relation to milk production. Among these is the relationship of a
low-calcium ration to lactation, compared with a similar ration
supplemented with bonemeal. Strength of bones as an approxi-
mate index of state of mineral storage is also under observation.
A richly-bred Jersey bull was donated to the Experiment Sta-
tion by William R. Kenan, Jr., Lockport, New York. This bull is
sired by Sophie 19th's Victor 171861, and from a very good
Register of Merit daughter of Pogis 99th of Hood Farm 94502,
one of the most famous cows of the Jersey breed.

BEEF HERD MANAGEMENT
During the past fiscal year a small beef herd was obtained by
this department. A good purebred Hereford bull was purchased
to head the herd, while the female stock consists of nine scrub
cows. It is hoped that more scrub cows may be added to the herd
in the future until a sufficient number is obtained to produce steers
of known breeding for use in grazing tests conducted coopera-
tively with the Agronomy Department. By having a herd of this
kind it will be possible also to show very definitely the advantages
of using a pure-bred bull on scrub cows in herd improvement work.

SWINE HERD MANAGEMENT
The swine herd management as practiced by the department
includes the use of annual grazing crops for the pigs and breeding
herd to prevent loss from internal parasites, since cultivation de-
stroys the worm eggs. The sows are bred to produce two litters
per year, one litter the latter part of February and the other the
latter part of August. During the past year a large number of
high class pigs have been produced. These pigs are used in
experiments in finishing hogs for market.

COOPERATIVE BEEF CATTLE GRAZING STUDIES
Through an agreement with the J. C. Penney-Gwinn Corpora-
tion a beef cattle grazing experiment is now being conducted at
Penney Farms, Florida. During the past year four lots of steers







Florida Agricultural Experiment Station


were used in these studies. Lots I and II consisted of 28 steers
each whire Lots III and IV were made up of five steers each. The
steers in Lot I were grazed on a 240-acre natural range pasture
which had been burned a few weeks prior to grazing. Lot II
steers were grazed on an adjoining 240-acre natural range pasture
which was not burned. Lot III steers were grazed on a 40-acre
pasture which was sown to improved pasture grasses, the grass
seed being sown broadcast. Lot IV steers were grazed on a 40-
acre area in which the grass seed were sown in strips.
The steers in Lot I made continuous gain until about the first
of July when they began to lose weight; however, the steers in
this lot did not lose weight as rapidly as did the steers in Lot II,
the unburned pasture. The total loss in weight of the steers in
Lot II was far greater for the entire grazing season than for those
in Lot I.
The steers in Lots III and IV, the improved pasture areas, con-
tinued to gain in weight until about November 1. Lot IV steers
made slightly greater gains than those in Lot III.
During the 1931 grazing season, Lots I and II were stocked to
14 steers each instead of 28 steers as last year and two additional
pastures were provided, each pasture consisting of 105 acres.
These pastures were burned and stocked to five steers each. The
steers will remain on these pastures for the entire year. The area
designated as Pasture No. 5 will be burned annually while Pas-
ture No. 6 will be grazed unburned. The steers on all lots are
weighed every 28 days. These tests should show the effects of
burning as influencing yields in beef production.
The work on this project is being conducted in cooperation
with the Agronomy Department.

DIAGNOSTIC LABORATORY REPORT
During the year 750 diagnoses were made of animal diseases,
the majority of cases being poultry. Some of the unusual findings
in poultry are given. One infestation of the Northern feather
mite, Liponyssus sylviarum (Can. & Fanz.) was diagnosed and
the parasite's identification confirmed by Dr. H. E. Ewing,
United States Department of Agriculture, Bureau of Entomology.
Caspillaria retusa, the small thread-like worm found in the intes-
tinal tract, was encountered in several birds and from all indica-
tions this parasite is on the increase in poultry of Florida. An
infestation of Ascarides was found in wild quail. The following
seven species of poultry tapeworms were encountered: Hymen-






Forty-fifth Annual Report, 1931


olepis carioca, Davainea cesticillus, Davainea tetragona, Dava-
inea proglottina, Davainea echinobothrida, Taenia infundibulum
and Amoebotaenia sphenoides. Birds affected with small blood
tumors of the skin have been presented for diagnosis from three
flocks in the state. These tumors were diagnosed as cavernous
angiomas. One of the birds held for observations showed pe-
riodic transudation hemorrhage from the comb and wattles.

VETERINARY SERVICE
Veterinarians in this department devote part of their time in
diagnosing and treating diseases which occur in the horses of the
University Field Artillery Unit, R. O. T. C., and in the livestock
belonging to the College Farm and Agricultural Experiment
Station.
RADIO TALKS
A number of popular reports of experimental work in dairying,
dairy herd management, swine feeding and management, beef
cattle management, and diseases of livestock and poultry have
been broadcasted over WRUF during the year.

RELATION OF CONFORMATION AND ANATOMY OF THE DAIRY COW
TO HER MILK AND BUTTERFAT PRODUCTION*
State Project No. 140 R. B. Becker, Leader
Measurements and records were obtained during the year of
four mature Jersey cows, Nos. 81, 120, 188 and 218, past useful-
ness in the Station dairy herd. To date, this station has con-
tributed a total of 11 such records to W. W. Swett, leader of the
cooperative project, Bureau of Dairy Industry, Washington, D. C.
Others will be added during the coming year.

SOYBEAN SILAGE FOR DAIRY COWS
Hatch Project No. 135 R. B. Becker, Leader
Biloxi soybeans were drilled at the rate of 38.5 lbs. per acre on
March 19, 1930. A yield of 87/8 tons per acre was harvested and
ensiled 133 days from date of planting. Methods outlined in the
1930 annual report were followed in securing further data con-
cerning silo capacity and changes that occur in the ensiling pro-
cess, with similar results.
Eight cows were used in the second feeding trial, comparing
*In cooperation with Bureau of Dairy Industry, USDA.






Florida Agricultural Experiment Station


soybean silage with No. 1 federal graded alfalfa hay, by the
regular double-reversal method. Computation of the results shows
that 3.10 pounds of soybean silage, moist weight, were equivalent
to one pound of alfalfa hay. No effect could be detected upon odor
and flavor of milk produced by these two feeds. The cow consumed
2.33 pounds of salt and 0.66 pounds of feeding bonemeal per head
each month during the feeding trial. Biloxi soybeans are being
grown this year for the third feeding trial.

A STUDY OF THE FEEDING VALUE OF CROTALARIA
Hatch Project No. 175 W. M. Neal and R. B. Becker, Leaders
Plans have been approved to begin a comparison of several
species of Crotalaria as feed for cattle, in cooperation with the
Agronomy Department and the Office of Forage Crops and Dis-
eases, USDA. The work will involve palatability, digestibility,
and comparative feeding trials according to standard methods.

DEFICIENCIES IN FEEDS USED IN CATTLE RATIONS
Purnell Project No. 133 W. M. Neal, A. L. Shealy and
R. B. Becker, Leaders
Field studies and cooperative field trials using mineral supple-
ments with so-called "salt sick" cattle have been continued. Bone-
meal proved ineffective to correct the condition. In certain in-
stances, forms of iron supplement were effective; in others, iron
plus copper were required. Some forms of both of these sub-
stances are injurious to cattle, hence judgment must be used in
administering them.
Additional cases of salt sick are being produced in the con-
trolled feeding trials. Forms of iron and copper supplements are
being compared. Calves used in this work are being donated by
Oscar Thomas, local dairyman.
Samples of native grasses were analyzed, and show a lower iron
content on affected than on healthy ranges. Samples of sufficient
size are being collected to obtain copper analyses. Soil types are
being identified and compared in cooperation with Dr. O. C. Bryan.
Histological studies of organs of affected cattle are being con-
ducted in cooperation with Dr. C. F. Ahmann.
A brief preliminary popular bulletin, dealing with the imme-
diate practical phase of cause and prevention of salt sickness, has
been published as Bulletin 231, I. Salt Sick: Its Cause and Pre-
vention, II. Mineral Supplements for Cattle.








Forty-fifth Annual Report, 1931


COMPARISON OF VARIOUS GRAZING CROPS WITH DRY-LOT
FEEDING FOR PORK PRODUCTION
Hatch Project No. 136 A. L. Shealy, Leader

Five fields of two acres each were planted to the following crops
to be used in finishing hogs for market: (1) Spanish peanuts and
corn, (2) Spanish peanuts alone, (3) corn alone, (4) chufas, (5)
Spanish peanuts and sweet potatoes. The crops in the first three
fields were ready for grazing by July 1, while grazing was de-
ferred on the last two areas until August 13. On July 1, 1930, 32
shotes were divided into four lots of eight each, designated as
Lots I, II, III and VI. The shotes in the first three lots were al-
lowed to graze the following field crops: Lot I, Spanish peanuts
and corn; Lot II, Spanish peanuts alone; Lot III, corn alone. The
shotes in Lot VI were fed a fattening ration consisting of 10 parts
corn and 1 part fish meal, this ration being fed in a dry lot. The
shotes averaged 81 pounds each and were of uniform size and
breeding.
On August 13, 1930, 24 pigs were divided into three lots of eight
each, designated as Lots IV, V and VII. The shotes in Lot IV
were turned in a two-acre field of chufas while those in Lot V
were allowed to graze in a field planted to Spanish peanuts one
acre and sweet potatoes one acre. The shotes in Lot VII were
fed 10 parts corn and 1 part fish meal, the feed being given in a
dry lot. During the grazing season the shotes which were fin-
ished on Spanish peanuts and sweet potatoes made the greatest
gain while those on Spanish peanuts and corn ranked a close
second.
Since the prevailing custom in this state when finishing shots
on chufas is to graze chufas alone, it was decided to follow that
practice even though chufas were decidedly unbalanced as a feed,
due to their low protein content. The shotes in this lot were al-
lowed to graze for a 90-day period and the eight shotes gained a
total of 226 pounds. Since many chufas remained unharvested
after the 90-day test period, it was decided to give fish meal as
a protein supplement to balance the ration. The fish meal was
fed in a self-feeder, and in a subsequent 58-day period the eight
shotes made a total gain of 600 pounds. It required 340 pounds
of fish meal to balance the ration in order to make this gain. It
appears from this test that it is necessary to supplement chufas
with fish meal (or tankage) to obtain economical gains. Further
studies along this line will be made in future tests.







Florida Agricultural Experiment Station


FATTENING FALL PIGS FOR SPRING MARKET
State Project No. 160 A. L. Shealy, Leader
Three fields of two acres each were planted to the following
crops to be used in finishing hogs for market: (1) runner peanuts,
(2) chufas, (3) oats. On December 16, 32 pigs were divided into
four lots of eight each, designated as Lots I, II, III and IV. The
shotes were allowed to graze the following field crops: Lot I, pea-
nuts; Lot II, chufas; Lot III, oats. The chufas were supple-
mented with fish meal while the oats were supplemented with
corn plus fish meal. Lot IV was fed 10 parts corn and 1 part fish
meal, the feed being given in a dry lot. The experiment was con-
ducted for a 60-day period. The shotes fattened on peanuts made
the greatest gains during this particular test period. The experi-
ment will extend over a period of five years.

THE VALUE OF GRAZING FOR FATTENING CATTLE IN BEEF
PRODUCTION
Hatch Project No. 137 A. L. Shealy, Leader
During the grazing season of 1930, 10 grade Hereford and 10
scrub steers were divided into five lots of four each and grazed on
five 3.5-acre pastures as follows: Lot I, mixture of carpet, Ber-
muda, Bahia, and Dallis grasses; Lot II, Bahia grass; Lot III,
centipede grass; Lot IV, Bermuda grass; Lot V, carpet grass.
Two grade Herefords and two scrubs were put in each pasture.
For this particular grazing season the steers on the centipede
grass pasture made the greatest gains, while those on Bermuda
grass ranked second. The grazing season began March 23 and
ended November 14, 1930. No supplemental feed was given; how-
ever, the steers had access at all times to common salt and feed-
ing bonemeal. The 1931 grazing season began March 28. Ten
grade Angus and 10 scrub steers are being used for this year's
studies. The work on this project is being conducted in cooper-
ation with the Agronomy Department.

THE COST OF WINTERING STEERS PREPARATORY TO SUMMER
FATTENING ON PASTURE
State Project No. 122 A. L. Shealy, Leader
Twenty steers were put on test December 18, 1930, and fed for
90 days. The steers received peanut hay as roughage plus a
grain mixture of equal parts ground snap corn and ground velvet
beans. The following data show the results of the test:






Forty-fifth Annual Report, 1981


Number of steers on test ................................. 20
Amount of hay eaten per steer per day ..................... 11.8 pounds
Amount of grain eaten per steer per day................... 3.23 pounds
Cost of peanut hay ...................................... 20.00 per ton
Cost of grain mixture .............................$... 30.00 perton
Cost of hay per steer per day .............................$ .118
Cost of grain mixture per steer per day ................... $ .048
Total cost per steer per day ...................... ...... $ .166
Initial weight of entire lot of 20 steers..................... 10,667 pounds
Weight at close of feeding period ......................... 11,405 pounds
Gain during feeding period.............................. 738 pounds
Average gain per steer for entire feeding period............ 36.9 pounds

It was desired to give sufficient feed to enable the steers to
make only slight gains. The steers were weighed once each week
during the feeding period.

ANAPLASMOSIS IN CATTLE
Purnell Project No. 149 D. A. Sanders, Leader

During the past year it was determined that the most common
blood-sucking external parasites affecting cattle in the area under
observation are various species of horseflies, stable flies, horn-
flies, mosquitoes, and ticks. During this period opportunity was
afforded to study two outbreaks of anaplasmosis as it exists in
nature under field conditions. Experiments on the transmission
of anaplasmosis are being conducted, and in these tests healthy
animals from the Station herd at Gainesville are being used.
After arriving at the isolation pens these animals are housed
under insect-proof conditions for a time corresponding to the in-
cubation period of anaplasmosis, after which they are exposed to
the attacks of the suspected vectors which have previously been
allowed to feed on diseased cattle. Constant observations for
many weeks are made on the animals thus exposed and records
of the temperature, pulse, respirations, number of red blood cor-
puscles, amount of hemoglobin, presence of anaplasmata, and
other symptoms of anaplasmosis are obtained. Further experi-
mental work will be necessary before it can be definitely stated
what relation, if any, these parasites have in the transmission of
the disease. It is evident that a study of several generations of
some of these external blood-sucking parasites will be necessary
in this investigation in order to determine what stage or stages
of the suspected parasite may transmit the infection.






Florida Agricultural Experiment Station


PARALYSIS OF DOMESTIC FOWL
State Project No. 119 E. F. Thomas, Leader

As in previous years, the major part of the work on this project
has consisted of attempting to transmit the disease to healthy
birds and to birds known to be infected with coccidiosis. Bac-
terial cultures taken from the intestinal tract of paralyzed birds
have been grown and injected intraperitoneally, intramuscularly,
and subcutaneously into healthy birds, but no cases of paralysis
have been produced. Further, such cultures have been introduced
in large doses into the gizzards of birds known to be infected with
coccidiosis with negative results. Macerated brain and nerve
tissues taken from paralyzed birds have been injected intraperi-
toneally, intramuscularly, and subcutaneously into birds of sus-
ceptible age with no cases of paralysis resulting. All these studies
will be continued in an effort to determine the cause of the disease.
Fowl paralysis has been diagnosed in 32 counties representing
every section of the state. Post-mortem examinations and de-
tailed records have been made on 111 cases. These records show
that all the paralyzed birds were affected with an enteritis in the
duodenal portion of the intestine; 63 were infected with coccidia;
41 had roundworms (Ascaridia lineata) ; 52 showed tapeworms
present; and 18 showed some enlargement of the femoral nerves.
Numerous other lesions were encountered, but they occurred so
inconsistently that they were not considered important.
Since coccidia have been found in a large number of the para-
lyzed birds, and since the control of these protozoan parasites is
apparently very important in the control of paralysis, experiments
are being conducted to determine how long coccidia oocysts will
live in the soil under natural conditions for this state. It is im-
possible to draw any definite conclusions at this time since work
has been in progress for only a short period of time.






Forty-fifth Annual Report, 1931


CHEMISTRY

In addition to the work reported on the various projects, 1,309
samples from the Agronomy Department were analyzed for mois-
ture and nitrogen content. A considerable number of soil samples
were tested for acidity and phosphate content for individuals in
the state. As usual a number of samples of rock were tested for
lime and phosphates and samples of water for iron content.
The work on urea carried on through a fellowship established
by the Synthetic Nitrogen Products Corporation was completed
and presented as a thesis for the Master of Science degree by
H. W. Jones in June, -1931. This is now in preparation for pub-
lication.
DIEBACK OF CITRUS
State Project No. 21 B. R. Fudge, Leader
The work of this project was carried on largely with material
from the Snell Grove near Lake Alfred. This grove is planted
on typical ridge soil set with Valencia oranges. It has been badly
affected with dieback for several years. The field and laboratory
work has been planned to study the difference in chemical com-
position between normal and dieback-affected trees. Previous
work had indicated that nitrogen played an important part in the
development of dieback, hence the past year's work has laid
special emphasis on the determination of forms of nitrogen in the
various tissues of both normal and dieback-affected trees.
The following nitrogen fractions are being determined: total
nitrogen, coagulable nitrogen, ammonia, nitrate, proteose, amide,
humin, basic and alpha amino-nitrogen.
The most notable differences found have been in the nitrogen
content of the stems of dieback-affected trees. These stems con-
tain about three times as much nitrogen as is found in normal
stems. Increased nitrogen was found also in the dieback-affected
leaves, but the differences were not as great as in the stems.
This difference is largely due to nitrate nitrogen though there is
also slightly more ammonia nitrogen in the dieback stems and
leaves. No significant differences in organic nitrogen compounds
have yet been found.
Analyses of the juice from normal and dieback fruit showed no
significant differences in nitrogen content. The normal fruit,
however, contained more acid and more sugar and had a much
higher osmotic pressure than did fruit from dieback trees.






58 Florida Agricultural Experiment Station

Studies are also being made on the carbohydrate and mineral
content of these tissues.

DETERMINATION OF THE EFFECT OF VARYING AMOUNTS OF
POTASH ON THE COMPOSITION AND YIELD AND THE
QUALITY OF THE CROP
Hatch Project No. 22 R. W. Ruprecht, Leader

The experiments with citrus at Lake Alfred were continued.
The low potash plots continue to have a better color than do the
high potash plots. No consistent differences in yield between the
plots has been found. This year the 3% and 5% potash plots out-
yielded the higher potash plots.
Fruit from all of the plots was placed in cold storage to de-
termine the keeping qualities. After six weeks no difference in
rate of decay was found between the different plots. In deter-
mining the specific gravity of the oranges it was found that those
from the 10% plots had a higher specific gravity than did those
from the 3% or 5% plots.
Sugar and acidity determinations on samples of the fruit show
no differences due to the amounts of potash. Mineral analyses
are under way but have not been completed. Due to lack of fa-
cilities no records regarding effect of the different amounts of
potash on the size or quality of the fruit could be obtained.
In the Irish potato experiment increasing the amount of potash
to 10 % in the formula increased the yield over the plots receiving
the same source of nitrogen and 5% of potash, but did not in-
crease the yield over the plots where urea was used as a source
of nitrogen, and 5% of potash was used.

DETERMINATION OF THE FERTILIZER REQUIREMENTS OF
SATSUMA ORANGES
Hatch Project No. 36 R. W. Ruprecht, Leader

The experiment at Marianna was continued as outlined in the
1929 Annual Report. The trees made a good growth and set a
small crop of fruit. Growth measurements showed no outstand-
ing differences due to fertilizer treatment.
A new Satsuma experiment duplicating the Marianna experi-
ment was begun at Penney Farms, the Penney Farms people fur-
nishing all of the fertilizer materials.







Forty-fifth Annual Report, 1931


DETERMINATION OF THE EFFECT OF VARIOUS POTASH CARRIERS
ON GROWTH, YIELD, AND COMPOSITION OF CROP
Hatch Project No. 37 R. W. Ruprecht, Leader
The experiment with citrus at Vero Beach on the East Coast
was discontinued at the request of the cooperator.
The yield records of this grove seem to indicate that for pine-
apple oranges any of the three sources of potash, high and low
grade sulfate or muriate, can be successfully used. The highest
yields have been obtained with a combination of muriate and sul-
fate. In the case of Valencia oranges and Marsh Seedless grape-
fruit, the highest yields have been obtained with the high grade
sulfate with little difference between the muriate and low grade
sulfate. In the case of Marsh Seedless grapefruit the use of
muriate and sulfate both during the year has in some cases
brought the yield almost as high as with the high grade sulfate.
With Valencia oranges, however, the yield where both sources of
potash were used is about the same as where muriate alone was
used.
The various sources of potash have had no appreciable influence
on the sugar and acid content, or size of the fruit. A more com-
plete analysis of these fruits is under way.
The grove at Lake Alfred bore a fair crop of fruit for the first
time. Samples were obtained and analyzed.

STUDY OF FERTILIZER REQUIREMENTS OF CITRUS TREES
WHEN GROWN ON MUCK SOIL
State Project No. 66 R. W. Ruprecht, Leader
The experiment was continued as outlined in previous reports.
Due to improved water control the trees at no time during the
year suffered from too much water. As a consequence they have
greatly improved. A general application of bluestone was made
at the time of the May application of fertilizer.

COMPOSITION OF CROPS AS INFLUENCED BY FERTILIZATION
AND SOIL TYPES-PECANS*
State Project No. 67 R. W. Ruprecht, Leader
The work on this project was continued as outlined in previous
reports. Samples of pecans were obtained from all but three of
the experiments. One experiment was discontinued.
*In cooperation with Bureau of Chemistry and Soils, USDA.






Florida Agricultural Experiment Station


Increasing amounts of fertilizer or increasing the percentage
of nitrogen does not seem to influence the protein or fat content
of the nuts. As stated in previous reports the source of nitrogen,
whether organic, or inorganic, apparently does not influence the
composition of the nut. Increasing the amount of potash in the
fertilizer has not as yet influenced the size of nut nor the per-
centage of fat or protein.
In general the nuts this year were larger than in the previous
year, regardless of fertilizer treatment.

EFFECT OF VARIOUS FERTILIZER FORMULAS
State Project No. 94 R. W. Ruprecht, Leader
The citrus experiment at Lake Harris studying the time of ap-
plication and amounts of phosphoric acid was curtailed by the
elimination of the tangerine trees. The owner cut these down
as they were budded on sour stock and had never made a satis-
factory growth. The oranges and grapefruit have made a good
growth and have set a good crop of fruit. Due to a misunder-
standing no records of fruit yield were obtained.
At Lake Alfred the source of nitrogen plots produced good
crops of excellent quality, especially of pineapple oranges. The
sulfate of ammonia plots again produced the largest yield of
pineapple oranges, with nitrate of soda second. Shortly after
the first of the year quite a distinct difference was noted between
Plots 1 and 6, and 2 and 7. In both cases Plots 6 and 7, receiving
phosphoric acid from steamed bone meal, had a better appearance
than the corresponding plots receiving superphosphate. The
oranges from these two plots were also judged to be the best,
based on external appearances. Preliminary partial chemical
analyses of the fruit showed no marked differences. Detailed
analyses have not been completed.
Grapefruit gave a higher yield from nitrate of soda than from
sulfate of ammonia. The yields from both the inorganic sources
were much higher than the yield from the dried blood plot, and
slightly higher than that from the combination of inorganic and
organic nitrogen plot. The most outstanding result is the rapid
recovery of Plots 5 and 10 since the source of nitrogen was
changed from manure to equal parts of ammonia from nitrate of
soda and sulfate of ammonia. These plots are now among the
best in the grove.
Five new experiments comparing organic and inorganic sources
of nitrogen were started during the year. The nitrogen for these






Forty-fifth Annual Report, 1931


experiments is being furnished by the manufacturers. These ex-
periments are located at the following points: Leesburg, Avon
Park, Port Mayaca, Homestead and Ft. Pierce. Four of these
soils are different from that found at Lake Alfred.
The experiment with Irish potatoes at Hastings was continued.
Due to wet weather, no top-dressing of nitrate of soda was ap-
plied. The plots receiving all the ammonia from urea again had
the largest yield, with the plots receiving 1/2 urea and /2 fish
scrap second highest. The single sources of nitrogen, nitrate of
soda, sulfate of ammonia, leunasalpeter and urea produced as
good yields as these same materials when used with organic
sources. Cutting down the amount of phosphate to one-half the
usual amount did not materially affect the yield.
The tomato experiment at Bradenton comparing sources of ni-
trogen was continued. Unfavorable weather cut down the yield
materially. The outstanding results were the poor growth made
by the calcium nitrate plots. The plots receiving all the nitrogen
from nitrate of soda likewise made a poorer growth than did those
.receiving other sources of nitrogen. However, when calcium
nitrate was used in combination with other sources, no detri-
mental results were noted. In fact, the best plots were those
where calcium nitrate was used to supply part of the nitrogen.

CONCENTRATED FERTILIZER STUDIES*
State Project No. 95 R. W. Ruprecht, Leader
The concentrated fertilizer experiment at Lake Alfred, con-
ducted in cooperation with the USDA, was continued. All of the
plots made a good growth and produced a fair crop of fruit. No
outstanding differences are apparent either in yield of fruit or in
the acid and sugar content of the fruit.
Due to lack of funds no active cooperation was taken with the
USDA in the truck crops experiments.
The citrus experiments at Lake Harris comparing urea, leu-
nasalpeter and sulfate of ammonia were continued. The tanger-
ine blocks were eliminated as the trees were cut down. All of
the trees made a good growth and have set a heavy crop of fruit.
No yield records were obtained due to a misunderstanding. No
harmful effects have as yet made their appearances.


*In cooperation with Bureau of Chemistry and Soils, USDA.







Florida Agricultural Experiment Station


DETERMINATION OF THE EFFECT OF GREEN MANURES ON THE
COMPOSITION OF SOIL
Adams Project No. 96 R. M. Barnette, Leader
The work on this project has been continued along the same
lines of investigation as previously followed. The main studies
include:
1. Observations made on the field experiments of the Agron-
omy and Horticultural departments.
2. Lysimeter studies on crop rotations.
3. Small tank studies on the methods of handling cover crops.
4. Small concrete plot studies on crop rotation.
The progress made on the various phases of these studies may
be summarized as follows:
1. Field Experiments: Samples of the soil of the cover crop ex-
perimental plots of the Agronomy Department at Lake Alfred
were taken at the beginning of the experiment and five years
later. Analyses of these soil samples show that, in the case of
each of the plots, regardless of the cover crop, the surface soil
lost organic matter and nitrogen during the course of the five
years. An average loss of approximately 20% in the organic
matter of the plots during the first five years, regardless of the
quantity of the cover crop returned to the soil, has been found.
On the basis of these results it appears that it is impossible to
maintain the organic matter content of the deep sandy soils
under the cultural practices prevalent at the Lake Alfred Station
despite the fact that a definite cover cropping system is being
followed. A heavily mulched block of trees has been added to the
experiment in an effort to maintain the organic matter content
of the system under this management and to study the effects of
mulching upon the growth and soil conditions. It appears that
organic matter must be supplied from outside the area under
culture to maintain adequately a decomposing soil organic matter
complex on these lighter types of dry upland soils.
Samples of soils from a cover crop experiment on the University
farm have been collected to follow the effect of different methods
of handling the cover crops (both summer and winter) on the
organic matter content of deep sands planted to pecan trees.
This experiment is in cooperation with the Horticultural De-
partment. The plan of the experiment calls for the following
different methods of handling: (1) Mulching with winter and
summer cover crops; (2) incorporation of winter and summer
cover crops; and (3) clean culture. The experiment calls for plots







Forty-fifth Annual Report, 1931


with and without ordinary fertilizer ingredients. After the exper-
iment has been carried out for some time, additional soil samples
will be taken and all the samples subjected to analyses. The
Horticultural Department will follow the response of the pecan
trees to the various treatments.
2. Lysimeter Experiments: The rotation experiments have
been continued on the soils of the large lysimeters. The amount
of leaching continues to be cut down by the higher yielding cover
crops and by winter covers of oats or vetch or Austrian peas.
Corn responds according to the season to the incorporation of
both summer and winter cover crops. The largest response of
corn is from a combination of summer and winter cover crops
(especially winter legumes).
3. Small Tank Studies: The experiment is conducted with
small galvanized iron tanks of Norfolk sand, with and without
rough lemon seedlings growing in them. These are subjected to
different handling of both the leguminous and non-leguminous
cover crops (Crotalaria striata and Natal grass). On some of
the tanks the cover crop is used as a mulch and on others it is
incorporated lightly with the surface soil. The non-leguminous
cover crop tanks receive an application of sodium nitrate. All
tanks received an application of phosphoric acid and potash in
the form of superphosphate and sulfate of potash. The periodic
leaching of nitrates and potash are being studied subsequent to
the application of the cover crop and the fertilizer. In a series
of tests on the leachings no appreciable amounts of phosphoric
acid were found coming through the two and one-half foot depth
of soil. Nitrates applied as nitrate of soda leached readily from
the soils of the tanks without trees. The soils of the tanks in
which Crotalaria has been incorporated showed a greater loss of
nitrogen than those in the tanks on which Crotalaria was used as
a mulch material.
Immediately after application, potash leached uniformly from
all the tanks. After the first large and rather uniform loss, pot-
ash was leached to the greatest extent from the tanks having the
organic matter incorporated but without trees. The soil of the
tanks in which organic matter was either incorporated or used as
a mulch showed a large absorption of the potash, evidently due
to the decomposing organic matter. This is significant in view
of the fact that the effect of the decomposing organic matter on
the available organic constituents of the soil is not fully appre-
ciated.






Florida Agricultural Experiment Station


It appears that the effect of the organic matter cannot be at-
tributed to only the effect which it has upon possible physical
and bacteriological properties of sandy soils, but that its effect
extends to the availability of mineral constituents as well. In
this connection, the potash supply to the tree and its absorption
by the tree seems to be definitely correlated with the presence of
a decomposing organic complex in or on the soil. This statement
is made for the sandy soils and does not necessarily apply to the
heavier types of soils in colder climates.
No correlation has been found between the solubility and ab-
sorption of phosphoric acid and the presence of a decomposing
organic complex.
4. Small Concrete Frame Rotation Studies: The rotation ex-
periment on the soils of the small concrete frames has been con-
tinued. A very satisfactory crop of hairy vetch was obtained fol-
lowing the incorporation of a summer cover of Crotalaria (Cro-
talaria spectabilis). The effect of the incorporation of the winter
cover crop upon the subsequent corn crop was found to be season-
al, dependent primarily upon the distribution of rainfall.
Dry weights of Crotalaria spectabilis decreased approximately
50 % by allowing the material to remain on top of the soil from
fall until early spring. Despite the fact that a relatively large
quantity of organic matter was returned to the soil.
The results of the two-year rotation experiment conducted by
the Agronomy Department have been compiled and placed in bul-
letin manuscript form, together with the soil data collected during
the course of the experiment.

EFFECT OF VARIOUS FERTILIZER TREATMENTS AND OF SOIL
AMENDMENTS ON TOMATOES
Hatch Project No. 112 R. W. Ruprecht, Leader

With the publication of Station Bulletin 218, Fertilizer Experi-
ments with Truck Crops, work on this project has been brought
to a close.

EFFECT OF FERTILIZERS AND SOILS ON THE COMPOSITION OF
TRUCK CROPS
State Project No. 141 R. W. Ruprecht, Leader

The work on this project is carried on with samples obtained
from some of the experiments reported in Project 94 and from
experiments carried on by the USDA.






Forty-fifth Annual Report, 1931


Preliminary analyses seem to indicate that the amount and
source of the fertilizer does not have an appreciable influence on
the composition of truck crops.

STUDY OF THE IODINE CONTENT OF FLORIDA GROWN CROPS
State Project No. 161 W. H. Conner, Leader

The work on this project was discontinued at the close of the
fiscal year due to lack of funds. The amount contributed by the
Florida Iodine Commission fell short $400.00 of the amount prom-
ised, so that it was necessary to carry on the work with state
funds the last four months.
A preliminary mimeographed report was issued the first of Feb-
ruary. A final report is in progress of preparation. A total of
26 different fruits and vegetables were analyzed. In comparing
the iodine content of these samples with the iodine content of
similar crops grown in South Carolina, no outstanding differences
were found except in the case of lettuce. A total of 110 samples
from 19 different localities in the state were obtained last year,
while this past season only 89 samples from eight different locali-
ties were obtained. This past season's results have been uni-
formly lower than those of the previous season. With the data
available it is impossible to determine whether this is due to
weather or some other conditions.
The experiments show that the iodine content can be very ma-
terially increased by the use of as little as 5 pounds of potassium
iodide per acre. Fish meal, when used as the source of nitrogen,
in one case also caused a marked increase in the iodine content.
No satisfactory determinations were made on citrus fruits due
to the lack of appropriate apparatus. In view of the probability
of the work being discontinued it was deemed inadvisable to pur-
chase these special pieces of apparatus.

A STUDY OF THE DECOMPOSITION OF FOREST, RANGE AND
PASTURE GROWTHS TO FORM SOIL ORGANIC MATTER*
Adams Project No. 166 R. M. Barnette, Leader
The major temporary problem of the project has been to de-
termine the effect of annual burning of "cut-over" and forest
lands on the development of the organic horizons of the soils. To
date some 200 samples from the comparable burned and unburned
*In cooperation with Southern Forest Experiment Station, USDA.






Florida Agricultural Experiment Station


areas have been submitted by the Southern Forest Experiment
Station for analyses. Nitrogen, carbon, hygroscopic water, loss
on ignition, replaceable lime and magnesia and the pH value of
water suspensions have been determined on these samples of
soil. The results of these analyses have been criticized and dis-
cussed with members of the staff of the Southern Forest Experi-
ment Station. The analyses appear to show that the effect of
annual fires on the different soil types must be considered on the
basis of the soil type.
A definite small increase in the amounts of nitrogen and carbon
in the different horizons of the sands and related well-drained
soil types apparently may be attributed to the burning over of
these types of annual fires.
The effect of the burning over of the heavier types of upland
soils and of the flatwoods soils is not so definite. On these types
the burning evidently has no, or extremely little, effect on the
organic matter of the soils. There is as much organic matter as
measured by nitrogen and carbon in the different horizons of the
burned as in the unburned soils.
The effect of burning on the organic horizons of the soil ap-
pears to be associated with ecological adaptations subsequent to
burning. Where vegetation is more or less definitely limited by
burning, as on the high sands and closely related types, there ap-
pears to be a definite effect on the organic horizons of the soils.
Where a succession of vegetation is possible, the vegetation sub-
sequent to burning seems to be adequate to maintain the organic
matter in the different horizons of the soil.
Studies on the soils of the large lysimeters sodded to Bahia
grass and cut at different intervals have been continued. The
more frequently cut Bahia grass sod appears to utilize more effec-
tively applications of sodium nitrate than do the less frequently
cut sods.






Forty-fifth Annual Report, 1931


COTTON INVESTIGATIONS
It is proposed, with the close of the present fiscal year, to as-
sign the different lines of cotton investigational work to the de-
partments concerned and discontinue a separate Cotton Depart-
ment. As of July 1, 1931, Dr. A. F. Camp, who has been in charge
of Cotton Investigations, is relieved of further responsibility in
this connection and his report, below, will be the final report from
the Cotton Department as such.
All cotton breeding work was transferred to the Tobacco Sta-
tion at Quincy in February, 1931. Dr. W. A. Carver, leader of
these projects, and R. M. Crown, Field Assistant, moved their
headquarters to the Tobacco Station with the transfer of the
work to that point. (The work on cotton insects is being con-
tinued at Gainesville.)
The following projects are involved in the transfer, and reports
of progress on these projects will be found under the report of
the Tobacco Station:
Project 57, Variety Testing and breeding.
Project 74, Field Tests with Cotton--Spacing and Time of
Planting Tests.
Project 101, Studies in Inheritance of Cotton.

CONTROL OF COTTON INSECTS
State Project No. 75 E. F. Grossman, Leader
A comparison of the emergence of the cotton boll weevil from
hibernation cages with the spring appearance of weevils in cotton
fields, started in 1926 and continued through 1930, was completed.
(Page 42, 1927 A. R.; page 40, 1928 A. R.; page 50, 1929 A. R.;
page 65, 1930 A. R.; Bulletin 233, pages 1-47, June, 1931.)
Though weevils emerged from artificial hibernation quarters pre-
pared in hibernation cages during a period extending from Febru-
ary to September, the appearance of weevils which emerged from
their natural hibernation quarters in the woods was usually lim-
ited to the latter part of May and the month of June. Counts of
weevils appearing in selected cotton fields provide accurate means
for forecasting weevil survival and abundance, whereas data ac-
cumulated from weevil emergence from hibernation cages fail
to do so.
During the latter part of November, 1930, 6,900 weevils con-
fined in eight small screen cages were placed in a constant tem-






Florida Agricultural Experiment Station


perature room maintained at 54" F. On June 30, 212 days later.
223 weevils, or 3.23 percent, were still living. In 1928, 10 percent
of 36,000 weevils lived for 236 days at 47" F.
To determine whether boll weevil damage is more likely to oc-
cur when there is a lack of uniformity among cotton plants in the
time they begin to blossom, the date on which each plant pro-
duced its first blossom was determined. Seven 100-plant blocks
of upland cotton and two 100-plant blocks of Sea Island cotton
were examined daily. The percent of the plants blooming in
certain specified periods after the first plant blossomed were
recorded as follows: 7 days, 25 percent; 11 days, 50 percent; 16
days, 75 percent; and 23 days, 90 percent for six of the upland
cotton plots. These blocks represented conditions fairly similar
to those found on farms where good cultural practices were used
in producing cotton on sandy loam soils. Obviously, such irregu-
larity among plants in time of beginning to blossom is an unde-
sirable characteristic under boll weevil conditions.
Six calcium arsenate-syrup mixtures of varying concentra-
tions of calcium arsenate, syrup and water were tested in the field
to determine their resistance to being washed off the plants by
rainfall. Specific amounts of the mixtures were placed on cotton
leaves and in the buds of cotton plants, respectively, and the resi-
due analyzed for arsenic after exposure to varying weather con-
ditions for different periods of time. Ninety percent or more of
the arsenic was washed off large leaves by rains varying from
0.1 to 0.3 inch. About 50 percent of the arsenic was lost over a
period of four or five days in the absence of rainfall. Where the
poison was applied to the succulent terminal buds the resistance
to washing shown by the syrup mixtures was much greater. An
average of 30 percent of the arsenic remained on the buds after
1.71 inches rainfall. No striking difference in the resistance to
washing was shown by any one of the six mixtures. In general,
the arsenic found on the leaves or in the terminal buds was
roughly proportional to the amount used.
A short series of toxicity tests was conducted by feeding speci-
fied numbers of boll weevils on the poisoned terminal buds. No
noticeable difference in toxicity was shown by the different mix-
tures. The composition of the syrup mixtures tested, arranged
in order of pounds of calcium arsenate, gallons of water and gal-
lons of syrup, respectively, was as follows:
1:3:1; 1:2:1; 1:1:1; 2:1:2; 2:1:1; 3:1:1.






Forty-fifth Annual Report, 1931 69

COTTON DISEASES-COTTON WILT
State Project No. 78 ................ Leader

This project has been discontinued. Work on resistance to wilt
is being continued at the Tobacco Station as a phase of Project
No. 57, Variety Tests and Breeding Experiments with Cotton.

COTTON PHYSIOLOGY-NUTRITION AND GROWTH
State Project No. 79 ................ Leader

With the transfer of Dr. M .N. Walker to watermelon disease
investigations at the Leesburg Field Laboratory, the study of the
chemical constitution of cotton plants at different stages of
growth and under different treatments of nitrates was suspended.
Nutrition and growth studies, involving fertilizer tests, are be-
ing planned for future work under this project.







Florida Agricultural Experiment Station


ENTOMOLOGY
FLORIDA FLOWER THRIPS
Adams Project No. 8 J. R. Watson, Leader

The Florida flower thrips was scarcer during the spring on
citrus blooms, tomato blooms, etc., than at any time since this
project was started. This was undoubtedly due to the cold, damp
weather of the winter and early spring-conditions very unfa-
vorable for the development of thrips. Because of this scarcity,
no experiments on the control of the flower thrips were conducted.
The survey of the Thysanopterous fauna of the state has been
continued, with special reference to the food plants and the eco-
logical distribution of the species. Especial attention has been
given to those infesting sugarcane. They are often quite abund-
ant underneath the leaf sheaths of the sugarcane and other
grasses. Their direct feeding seems to be of little consequence,
but there is some evidence that they may be the carriers of dis-
ease.
We have been determining all the Thysanoptera collected by
the P. Q. C. A. of the Department of Agriculture.

ROOT-KNOT INVESTIGATIONS
Adams Project No. 12 J. R. Watson, Leader

Most of the work under this project this year has been a con-
tinuation of the cultural means of control, which consists in grow-
ing immune plants on the ground during the summer under con-
ditions of frequent cultivation and freedom from weeds, a method
of eradication developed in this state. During previous years the
rigid application of this means of dealing with root-knot has uni-
formly resulted in commercial control. Most of the work during
the past year has been with Crotalaria spectabilis, as this plant
yields much better to this method than do velvet beans. One
rather heavy infestation of root-knot has been found on Crota-
laria striata.
The degree of control obtained by simply allowing a volunteer
crop of Crotalaria to grow after the vegetable crop without culti-
vation is also being investigated. All the varieties of Crotalaria
of which we could obtain seed are being grown on heavily infested
plots to test their susceptibility to root-knot.







Forty-fifth Annual Report, 1931


INTRODUCTION AND STUDY OF BENEFICIAL INSECTS
Hatch Project No. 13 W. L. Thompson, Leader

Cryptolaemus montrousieri
In November, 1930, a colony of Cryptolacmus ladybeetles was
received from the Agricultural Experiment Station of California
for the purpose of aiding in the biological control of mealybugs
attacking citrus and bulbs. During the past winter and spring
the beetles were reared on mealybugs, which in turn were reared
on potato sprouts. Up to June 30, more than 40 colonies had
been distriubted over the citrus belt. In the laboratory these
beetles, adults and larvae, were observed feeding on aphids, cot-
tony cushion scale and the false cochineal insect. The life cycle
of this beetle required approximately 30 days in May and June.
In the Citrus Experiment Station grove, beetles were liberated in
two different plots. Ant nests were destroyed in one plot and al-
lowed to remain undisturbed in the other, to determine whether
ants are a factor in the welfare of the beetles. It is hoped that
these beetles will also aid in the control of mealybugs attacking
bulbs in storage.
These beetles have also been raised at Gainesville by Mr. Brat-
ley, and especial attention has been given to the observation of
the possible foods for the Cryptolaemus. It is obvious that the
larger the range of food of these beetles the better will be the
chances of their becoming permanently established, and also of
their usefulness. Experiments have shown that these beetles will
feed on practically all species of mealybugs in the state, including
the false cochineal scale on cactus. The adults, however, cannot
be raised on this insect, since their feet become entangled in the
cottony mass and they perish, but it makes a very favorable host
for the larvae of the Cryptolaemus, and is very easily raised.
They have taken readily to the mealybugs that grow on the roots
of sumac and ragweed. These have served as emergency rations
for the beetles in our work. They will also feed on many species
of aphids. They have completed their entire life history on the
citrus aphid.
Sugarcane Borer
Observations of the cane borer are being continued. The plot
of cane on the Citrus Station grounds had less than 1 percent
infestation last fall. Additional plantings of various varieties
have been made in cooperation with the Everglades Experiment
Station.







Florida Agricultural Experiment Station


LARGER PLANT BUGS ON CITRUS AND TRUCK CROPS
State Project No. 14 H. E. Bratley, Leader

The past year a general survey of the plant bug was made and
some life history work continued. The Southern green stink bug,
Nezara viridula, was by far the most plentiful, with the leaf-
footed plant bug, Leptoglossus phyllopus, second.
In the fall of 1930, where cowpeas were followed by Crotalaria,
there seemed to be a fairly heavy infestation of the Southern
green stink bug, although in a few scattered areas the leaf-footed
plant bugs were more numerous. These cover crops being in
citrus groves, considerable damage was done to the citrus, espe-
cially where improper cultural methods were practiced. Even
when these bugs were very plentiful, with proper methods of
cutting the cover crop, very little damage to the citrus was noted.
The parasites were well distributed over the state, but were not
plentiful enough to hold the bugs in check. The feather-legged
fly and another rather large Tachina fly were responsible for this
good work.
In the early spring both of these plant bugs were plentiful on
thistles. The Leptoglossus phyllopus seem to have a special liking
for this plant, especially after it starts the shooting of the flower-
ing stem. They may be found on it from the time it appears
until the crop of seed has ripened.
A good course to follow would be to destroy these thistles for
some distance about a grove or trucking area. The favorite food
of these large plant bugs seems to be cowpeas, and Crotalaria
when young pods are present. Many of the bugs used in life-
history work were killed by diseases. These seem to be much
more prevalent and destructive to the bugs when confined than
in the field. A few other bugs have been reared and identified,
but the damage caused by them is slight in comparison with the
two mentioned.

STUDIES OF THE BEAN JASSID
Adams Project No. 28 A. N. Tissot, Leader

This work was continued up to the time Mr. Tissot left (Jan. 1,
1931). As a result of his work it would seem that the pyrethrum
compounds are the only insecticides which can be recommended
for the control of jassids. Although they are higher in price than
nicotine compounds, the kill they give is so much better that their







Forty-fifth Annual Report, 1931


use on such a high priced crop as early fall beans is fully justified.
The work has demonstrated also the importance of a fallow or
burned-over area around the edge of a bean field to check the
immigration of jassids into the field from the outside. The rec-
ommendations in this respect have been quite generally followed
by bean growers.

THE GREEN CITRUS APHID (Aphis spiraecola)
Adams Project No. 60 W. L. Thompson and L. W. Zeigler,
Leaders

During the past year the citrus aphid investigations have been
continued along the same lines as during the last three years with
the exception of a few minor changes in taking records.
The general aphid infestation was very light. Less than 1 per-
cent of the spring flush of growth on oranges was infested and
approximately 3 percent on tangerines. (These figures were ob-
tained from weekly records from three typical groves in the Lake
Alfred section.) The peak of aphid reproduction was reached
during the week of March 23, four weeks later than last year.
Although there was an excess of rain during January and Feb-
ruary, the average temperature was below normal and little or no
succulent growth was present on oranges and tangerines during
November, December and January.
Aphid predators were rather scarce until late in the spring.
The syrphid fly, Syrphus wiedemanni, was more abundant than
usual and Baccha clavata rather scarce. The blood red ladybeetle,
Cycloneda sanguinea immaculate (Fab), was not so abundant as
last year, but the Southern two-spotted ladybeetle, Olla abdomi-
nalis var., was more abundant than it has been since 1928. Em-
pusa fresenii, the fungus which attacks the aphids, was very
scarce during the whole aphid season.
Artificial Control: A shale oil used at 1 to 50 gave a kill less
than 50%. When combined with dry lime-sulfur as recom-
mended, a 98% kill was obtained but succulent foliage was se-
verely burned. Kaloil, a combination of penetrol and pyrethrum,
did not give a satisfactory control-Kaloil 1 to 1,000, 65% kill;
1 to 800, 70% kill; 1 to 600, 80% kill. A combination of lime-
sulfur, 1 to 40, penetrol 1/ percent, and black leaf 40, 1 to 3,000,
gave a 99% kill with no burning.
In addition to the work of Mr. Thompson, Mr. Tissot continued
his work on aphids until he left in late December, since which






Florida Agricultural Experiment Station


time his work has been carried on by Mr. Zeigler. His survey
of the Aphidae of Florida is about ready for publication. It will
contain descriptions of 20 new species of aphids.
The citrus aphid work has been carried on in close coordination
with the work on the melon aphid by Mr. Goff.
The work of the year has again demonstrated the great im-
portance of the winter cleanup of aphids as a preventive of a
general infestation in the spring. If the groves can be kept free
of aphids until the middle of March when the general flight takes
place, the damage to the first flush of growth in the spring will
not be heavy except possibly in the case of tangerines. The gen-
eral spring flight was about a week later than usual this year,
commencing about the 20th of March. The studies during the
past winter have given further support to the previous observa-
tion that the character of the weather during December and es-
pecially January is the most important factor in determining
whether aphids will be numerous in the spring. If the mean
temperature for the month of January is below 60, and particu-
larly if it is at the same time dry, the chances are very much
against a heavy infestation.

CONTROL OF DECIDUOUS FRUIT AND NUT CROP INSECTS
State Project No. 82 Fred W. Walker, Leader

Nut Case-Bearer: The experiments with dormant sprays for
the control of the nut case-bearer, Acrobasis sp., were continued.
Some of the emulsions tried out were not so promising as the
experiments showed last year. One emulsion, however, is out-
standing, showing from 90.7 to 97.5% kill in the laboratory tests
and 87.7% kill in the field without any injury to the buds.
The experiments with stomach poisons were continued with
the same results that were obtained before. The results in all
experiments have been negative, showing that the use of ar-
senicals for the control of this insect is a waste of time and ma-
terial.
The nut case-bearer was late in emerging this year and in most
localities not so numerous as last season.
Eighty thousand Trichogramma minutum, an egg parasite of
the nut case-bearer, were liberated in two groves at Monticello.
These were liberated too late for the majority of the eggs of the
nut case-bearer, but recoveries have been made from the eggs of
the leaf case-bearer.







Forty-fifth Annual Report, 1931


Leaf Case-Bearers: Three species of leaf case-bearers belong-
ing to the genus Acrobasis are found in the groves and nurseries
around Monticello. One feeds almost exclusively on the seedling
nursery stock, the other two are generally found in the groves
and only in limited numbers in the nurseries.
The experiments with summer sprays for the control of the
leaf case-bearer were continued with good results. The work on
this insect has progressed far enough that a bulletin manuscript
can be prepared. The results of the various sprays tested show
that almost any arsenical stomach poison is suitable for the con-
trol of this insect, provided the work is thoroughly,done and the
underside of the leaves well covered. The use of a spreader in
the mixture or a spray pump delivering a high pressure at the
nozzle will add to the percentage of kill. Checks also were made
on sprays applied by the different growers. These checks show
a varying percentage of kill according to the thoroughness of ap-
plication.
A heavy infestation of the predaceous mite Pediculoides sp. was
found on larvae of the leaf case-bearer in West Florida. The per-
centage of parasitism is also higher there, so this may account
for the scarcity of these insects in most of the West Florida
groves.
Shuckworm: The studies and experiments on the shuckworm,
Laspeyresia caryana, were continued throughout the year.
The burying experiments show that the insect can be controlled
by the plowing under of the husks provided the work is done after
the majority of the larvae have pupated. This is generally be-
tween the 1st and 15th of March. By far the best method of con..
trol, however, is the gathering of the nuts on sheets and piling
the husks in piles for burning as soon as dry enough.
A survey of shuckworm infestation at harvest time in the Mon-
ticello area showed an average of 65.9% of the nuts infested with
the larvae of the shuckworm. Green nuts collected at harvest
time at Tallahassee showed an infestation of 91.7%.
Black Hickory Aphid: This insect, Melanocallis fumipennella,
is beginning to be one of the major pests of the pecan. Last sea-
son considerable damage was done by the aphids in defoliating
the trees. This not only caused a reduction in the crop on the
infested trees last season, but caused the loss of the crop on those
trees this season from lack of pollination. The damage done by
this insect evidently is due to some toxic substance injected into
the tissues of the leaf while the insect is feeding. The leaves first






Florida Agricultural Experiment Station


turn yellow, then reddish brown and then soon curl up and fall to
the ground. The toxic substance injected into the leaves probably
destroys the chlorophyll.
The black aphid shows a decided preference for certain varie-
ties, mostly those with dense foliage. There is little preference
shown as to position on the leaves, however, as they feed on both
surfaces of the leaves. The shady portions of the trees are usually
most heavily infested.
Experiments in the control of this insect were conducted last
season with fair results. Unfortunately, the materials are much
too expensive for general use in a pecan grove. Experiments are
now being conducted with lime-sulfur sprays for the control of
this insect. Laboratory tests with this material show a high per-
centage of kill even with a fairly weak solution.
Cigar Case-Bearer: This insect, Coleophora caryaefoliella, is
of little importance in the eastern part of Florida but is one of
importance around Pensacola and Milton where it sometimes de-
foliates the trees. As the insect is a leaf miner it is impossible to
get a satisfactory control with stomach poisons. Experiments have
been conducted with various contact insecticides in both field and
laboratory with negative results. This is not surprising, however,
since the insect is resistant even to fumigation with cyanide.
Twig Girdler: This insect, Oncideres cingulatus, did consid-
erable damage in most of the groves around Monticello last season.
As many as 100 twigs were cut from some trees. Life history stu-
dies are being carried on.
Miscellaneous Pecan Insects: Studies are being conducted on
practically all of the pecan insects in the vicinity of Monticello.
Blueberry Fruit Worm: This insect, Acrobasis vaccinii, is do-
ing considerable damage to the blueberry crop in some sections.
Around Milton some of the plantings show around 60% loss, at
Monticello one planting shows from 15 to 25% loss. Life history
studies are being carried on with the object of working out a suit-
able and economical method for the control of this insect. The prob-
lem was started too late this year for much to be done on it; how-
ever enough was learned of the habits of the insect that relief can
be had by the growers who use a cultural method of control and
destroy the overwintering pupa cases on the surface of the ground.
The insect is single brooded and spends the winter in a case of
sand and silk placed on the surface of the ground underneath the
leaves.






Forty-fifth Annual Report, 1931


LIFE HISTORY STUDIES OF THE ROACH WHICH IS THE
INTERMEDIATE HOST OF MANSON'S EYEWORM
State Project No. 108 A. N. Tissot, Leader

This roach is Pycnoscelus surinamensis Linn. The project has
been inactive during the year.

MEALYBUGS
State Project No. 155 J. R. Watson, Leader

Work on this project during the past year has centered around
the raising of Cryptolaemus ladybeetles and their liberation in
groves and ornamental plantations. Many hundreds of ladybeetles
have been raised and these have been distributed mostly in citrus
groves, but some have been liberated among insects of ornamen-
tals, mostly on bulbs, coleus, etc.
A further report on this work is found under Project 13, with
which it was merged.

GREEN SPIDER ON ASPARAGUS PLUMOSUS
State Project No. 156 J. W. Wilson, Leader

Work under this project relating to the green spider, Tetrany-
chus telarius L., has been about concluded and bulletin 234, The
Two-Spotted Mite on Asparagus Plumosus, has been prepared for
publication.
It has been demonstrated that this mite can be controlled either
by sprinkling the ferns twice a week or by two applications of a
white oil, such as "Volck," at an interval of about a week. This
mite has been carried into the Leesburg section, where it is pres-
ent in half a dozen ferneries.

INSECTS OF ORNAMENTALS
State Project No. 157 J. W. Wilson, Leader

An investigation has been made of an outbreak of cicadas on
Asparagus plumosus at Jupiter. The cicada was identified and
its life history was in part determined. It was found that the
eggs were deposited in the slats of the sheds from which the lar-
vae undoubtedly dropped to the ground. It was found that these
eggs were highly parasited but the parasites have not as yet






Florida Agricultural Experiment Station


emerged from the eggs collected. The application of water un-
der pressure to the beds proved a very effective method of con-
trolling this cicada. It is believed that this is the first applica-
tion of the principles of hydraulic mining to economic entomology.
The cicadas washed from the roots and washed around in the sand
were either killed or were so far removed from the roots as to be
unable to re-establish themselves. The resultant stirring of the
soil was very beneficial to the Asparagus.
An investigation of the caterpillars of Asparagus has been
started, with Mr. C. C. Goff assisting in the work during the slack
season for melon aphids.
Mr. Bratley has investigated the life history and control of sev-
eral insects of ornamentals, mostly caterpillars, including the ole-
ander defoliator, the rubber tree defoliator, and the phyllanthus
measuring worms.


INSECT AND OTHER ANIMAL PESTS OF WATERMELONS
State Project No. 162 C. C. Goff, Leader

On May 20, 1930, life history work was started on the melon
aphis. These aphids were raised on young melon plants in pots
and were covered with lantern chimneys. They were kept in the
insectary, a small building roofed over but with the sides of screen
only, giving free air circulation. It was not until about the
first of July that a hygrothermograph was available so that this
work is being continued until the work has been carried on a full
year with a complete record of temperature and humidity.
One series was made up by selecting the first born of each gen-
eration. Fifty-one generations were born from May 20, 1930, to
May 20, 1931. Forty-six of these completed their life cycle. A
second series was run selecting the last born of each generation.
The same aphid was used to start this series as was used in the
first-born series. Seventeen generations were born and 16 of
these completed their life cycle.
From these two series the following averages for the year were
obtained:
Days
Average development period ...................................... 7.2
Average reproductive period ............................. ...... 15.6
Average post-reproductive period ................................. 5.2
Average length of life ............................................ 28.0
Average number of young born to each individual ................... 67
Average number born per day during reproductive period .............. 4.3






Forty-fifth Annual Report, 1931


A third series was run in the greenhouse during the winter to
get a comparison with those outside. From November 4, 1930,
to May 20, 1931, the average temperature in the greenhouse was
73" F. while the average temperature in the insectary was 60.6 F.
During this time there were 30 generations born in the green-
house and 20 born in the insectary.
In one field the aphids were found to live and reproduce through-
out the winter on Eupatorium petaloideum. This was in a rather
low place and the temperature must have been a few degrees be-
low freezing two or three times.
This spring the aphids were not abundant, although all the
growers dusted their fields at least once. A 2 percent dust made
from 50 percent free nicotine and with lime as the carrier gave
good commercial control in the experimental field. A light tin
funnel was fastened on the end of the duster and used while the
plants were small. This makes it possible to dust regardless of
the wind.
Mice have caused considerable trouble to the growers by dig-
ging up the seed, in some cases making it necessary to replant a
second or third time. A strychnine poisoned bait of scratch con-
trolled the mice in the experimental field where a great deal of
damage was done the year before. Poisoning the watermelon
seeds was not successful, as the mice peeled off and discarded the
outer portion, eating only the inner part of the seed. They, there-
fore, ate a large number of seeds before getting enough poison to
kill them.
As the watermelon season is closing, work is being done on the
life history of the caterpillars attacking ferns and on the control
of these insects.

CONTROL OF THE INSECT PESTS OF STORED CORN
State Project No. X E. F. Grossman, Leader

Control of the insect pests of stored corn was attempted by ap-
plying heat to the stored corn. The lethal amounts of heat nec-
essary to kill all stages of the insects commonly infesting corn in
Florida; the amount of heat the corn itself could withstand with-
out injury to subsequent germination or plant vigor; and the pos-
sibility of heating a mass of corn to the necessary temperature
were determined.
An exposure to 50' C. (122 F.) for one hour will kill all stages
of the insect pests of stored corn. Ten minutes at 80 C. (176' F.)






80 Florida Agricultural Experiment Station

will injure the corn seed, but five hours at 59" C. (138.2 F.) does
not injure the germination or subsequent plant growth.
Slip-shucked corn cannot be effectively heated for controlling
the insect pests of stored corn. Shucked corn, however, when
spread to a depth of three feet on the flooring constructed on the
lowest tiers of a tobacco barn, can be effectively heat-treated with
an 18-hour exposure; spread to a depth of 21/2 feet, after 13
hours, if the air temperature in the tobacco barn is maintained
at a minimum temperature of 83" C. (181.4* F.).






Forty-fifth Annual Report, 1931


HOME ECONOMICS

DETERMINATION AND IDENTIFICATION OF THE ORGANISMS
WHICH CAUSE THE SPOILAGE OF CANNED VEGETABLES IN
THE SOUTH
Purnell Project No. 69 Ouida Davis Abbott, Leader
The experimental work on this project has been completed. A
bulletin manuscript will be prepared shortly.


DETERMINATION OF WHETHER CHLOROPHYLL, CHLOROPHYLL
ALPHA AND BETA, THE PETROLEUM-ETHER EXTRACTS OF
THE YELLOW PIGMENTS OF ALFALFA, CAN BE USED
AS A SOURCE OF VITAMIN A IN ANIMAL NUTRITION
Purnell Project No. 70 Ouida Davis Abbott, Leader
Work for the past year has been concentrated on the prepara-
tion of carotin and xanthophyll, and the feeding of these pig-
ments to rats as a source of vitamin A. It has been found that
when carotin was fed at the rate of .003 to .005 mgs. per rat per
day it promoted growth and prevented xerophthalmia in rats on a
vitamin A-free diet, while xanthophyll fed at the same levels had
no effect. A similar effect was observed when the oil obtained
by extracting corn pollen with petroleum ether was fed at low
levels.
A study has been made of the blood changes which occur in
rats on a vitamin A-deficient diet. It has been found that there is
a striking decrease in the polymorphic nuclear and an increase
in the mylocytes in the blood of rats on a diet deficient in vitamin
A. There is also a change in the color of the hemoglobin and a
decrease in the blood volume.


A STUDY OF SOME OF THE CONSTITUENTS OF CITRUS FRUITS,
LOQUATS, ROSELLE, AND GUAVA: PECTINS, OILS AND GLUCOSIDES
Purnell Project No. 71 Leonard W. Gaddum, Leader

The work on the pectins has been practically completed; the re-
sults will appear in a bulletin manuscript to be prepared in the
near future.
Pectin extraction has been carried out according to some four
different methods, the pectin obtained being tested as to viscosity,
jell strength, etc.







Florida Agricultural Experiment Station


The composition of the citrus fruits studied (orange, grape-
fruit, kumquat, lemon) was found to be closely similar in regard
to degree of methylation, calcium pectate content, ash, acidity
and pH. On the other hand, the pectin made from kumquats and
oranges was distinctly lower in jellying power than that made
from lemons and grapefruit.
The pectin prepared from the early green fruit was found to
be more alike in composition than that prepared from the later
green fruit or from ripe fruit. Also, the pectins made from the
early grapefruit showed much closer jellying power and viscosity
than that from the more mature fruit.
The comparison of the properties of the various pectins is dif-
ficult without the use of tables and graphs and consequently this
will be reserved for the bulletin.

THE RELATION OF GROWTH TO PHOSPHORUS, CALCIUM AND
LIPIN METABOLISM AS INFLUENCED BY THE THYMUS
Purnell Project No. 142 C. F. Ahmann, Leader

Method of Thymectomy
A modification of the usual method of thymectomy has made
it possible to remove the thymus by cutting one rib, while here-
tofore it had been necessary to cut two and sometimes three
ribs.
A special study has been made of several anesthetics in this
operation. It has been found that intraperitoneal injection of
barbitol, 300 mgs. per kilo of body weight, gave the most satis-
factory results. The animals used were rabbits.

Effects of the Removal of the Thymus
The Effect on Growth: The effect on growth was determined
by weight and also by measurement of the long bones. It has
been shown that animals thymectomized at an early age, three
to four weeks of age, make nearly the same growth as the con-
trols up to the age of five months, or when sexual maturity is
reached. As sexual maturity is approached the thymectomized
animals fail to make the gain in weight which the control ani-
mals make. At the age of eight months the average weight of
the control animals in this study was 25% greater than the av-
erage weight of the thymectomized animals. The growth in
length of the controlled animals was 18% greater than the growth
in length of the thymectomized animals.






Forty-fifth Annual Report, 1931


The Effect on the Age of Sexual Maturity: It was found in
every case that the male and female thymectomized animals be-
came sexually mature at an earlier age than the control animals.
In one case the thymectomized animal arrived at sexual maturity
six weeks earlier than the control.
The Effect of Thymectomy on the Size of the Offspring: The
average weight of one-month-old rabbits from control animals
was 240 grams, that of offspring from thymectomized rabbits
was 204 grams. This represents about a 15% difference.
The Effect on the Ca., P., and Lipin Content of the Blood: The
results thus far indicate an increase in blood cholesterol following
thymectomy and a decrease in the lecithin content of blood. The
results on Ca. and P. have been inconsistent, with a tendency,
however, to a lowering of the blood P.

The Effects of Intra-Peritoneal Injection of Certain Thymus Extracts
Acid extracts of fresh and desiccated thymus produce a marked
rise in blood P. Alkaline extracts, however, produce a drop in
blood P.
The Effect of the Removal of the Testes
This study has shown that the thymus of a castrated animal
is larger than that of a control animal of the same age and con-
dition. It is also shown that the age, when involution of the
thymus takes place, is greater in castrated animals than in con-
trols. Rats and chickens were used in this study.

Effect of Deficient Diets on the Size of the Thymus
Feeding experiments with deficient diets have shown that the
thymus is the gland to first show any gross change. Complete
atrophy except for a few microscopic remnants has been brought
about by these diets. Thus the condition of the thymus is an in-
dex to the state of nutrition of an animal.

OTHER STUDIES
In addition to Purnell Projects 69, 70, 71 and 142, the Depart-
ment of Home Economics Research has two cooperative projects
and six minor projects for which no funds have been allotted.
Realizing the practical importance of these projects, the regular
labor and the departmental staff have worked on them at night
and at spare times. The material for the work has been con-
tributed by other departments. Progress reports are as follows:






Florida Agricultural Experiment Station


Cooperative Projects: C. F. Ahmann, Leader
1.-Histologic Studies of Salt Sick Cattle.
Histologic studies are being made on tissues from salt sick
cattle used in Purnell Project 133 of the Department of Animal
Husbandry.
2.-A Study of Crotalaria as a Forage Crop for Rabbits.
(Office of Forage Crops and Diseases and Department of Agron-
omy cooperating.) Work has just begun on this project.

Minor Projects:
1.-To Determine an Effective Way to Prevent the Develop-
ment of Rancidity in Pecans.
In an attempt to prevent the development of rancidity in pecans
the following methods are being tried: (1) Preservation of the
nuts in dark glass bottles in an atmosphere of (a) hydrogen,
(b) nitrogen; (2) vacuum, 25 cm., (3) canned by heating in an
autoclave 45 minutes at 15 pounds pressure. The pecans are
stored at 400 F. and at room temperature to note the effect of
temperature on the prevention of rancidity.
2.-A Comparison of the Cooking Qualities and Chemical Com-
position of Two Varieties of Potatoes Grown in Florida,
Spaulding Rose and Bliss Triumph.
It has been found that the Spaulding Rose has a thin cortical
layer and external medullary area uniform in density, and a
small internal medullary area which has a fairly even distribution
of starch. A potato possessing the above characteristics be-
comes mealy when cooked. Having a relatively narrow cortical
layer this breaks apart and falls off when it is boiled. This potato
should be used for French frying, potato chips and for baking.
The Bliss Triumph has a relatively wide cortical layer, and an
internal medullary area poorer in starch than the Spaulding Rose;
therefore the Bliss has a tendency to become soggy when baked.
Experiments are now in progress to determine the relation of the
temperature and time at which these two varieties are stored
to the development of sufficient sugar to make them unfit for
potato chips. The temperatures at which the potatoes are stored
are 31, 42 and 60 degrees F.
3.-Can a Good Quality of Table Vinegar Be Made from the
Juices of Citrus Fruits and from the Juice of Blackberries?






Forty-fifth Annual Report, 1931


Vinegar has been made from the following fruit juices: orange,
grapefruit, tangelo and blackberry. It has been found that a
combination of tangelo with either grapefruit or orange gives a
better vinegar than either juice alone. The acid content of the
vinegar made in 1930 is as follows: tangelo and orange, 7%;
tangelo and grapefruit, 6%; orange and grapefruit, 5%; orange,
4%, and grapefruit, 3%. The juice to which tangelo juice was
added fermented more vigorously and a higher yield of alcohol
was produced either with or without sugar than when any other
combination was used. The sugar content of all the fruit juices
on which experiments were conducted was too low to produce a
vinegar containing 4.5 % acetic acid, the amount required by law
before a condiment can be classed as a vinegar; therefore, one
pound of sugar was added to each gallon of juice.
An organism has been isolated from orange juice which fer-
ments alcohol to acetic acid very rapidly. Acetic acid fermenta-
tion usually proceeds slowly and often a fermentation period of
from 6 to 12 months is required to produce a vinegar containing
4.5% acetic acid; however, with the inoculum used in this work
acetic acid fermentation was complete in two months with the
above results.

4.-Hair-Eating in Rabbits.
A number of rabbits from different parts of the State were
sent to this department for examination. These rabbits were in
an emaciated condition. The hair had come off in patches, and
they were weak and malnourished. Upon close examination and
observation, it was found that when several rabbits were kept
in the same hutch they ate the hair from one another. As the
chief amino-acid in hair is cystine, it was assumed that the lack
of this acid might be responsible for the above symptoms. The
rabbits were divided into three groups. Group No. 1 received
200 mgs. cystine in addition to the regular grain ration; No. 2
received a supplement of dried skimmilk; and No. 3 was put on
the regular stock food which contained dried skimmed milk and
alfalfa. With an improved diet the hair eating stopped and all
the rabbits gained in weight. At the end of four months all of
the rabbits were in a well-nourished condition. The animals
which received the cystine as a supplement had made gains com-
parable to those on the milk and the regular stock food. It
seems logical to conclude that the lack of cystine was the cause
of this condition.







Florida Agricultural Experiment Station


5.-Jellying Properties of Certain Varieties of Grapes and
Blackberries Grown at the Experiment Station.
Jellies have been prepared from the following varieties of black-
berries and grapes: Blackberries:- Marvel, Haupt, Oregon.
Grapes:-Lukfata, Husman, Munson, Jacquez, Sabinal, Salaman-
der, Champanel, Elvicand, and Jaeger. Using the same pro-
cedure in all cases, it has been found that the Marvel blackberry
makes a less desirable jelly than either the Haupt or Oregon, and
that the Husman grape was the least desirable grape for jelly
making. These experiments are being repeated this year.
6.-Hookworm Studies.
A study is being made to determine the constancy of the num-
ber of hookworm ova passed from time to time by a hookworm-
infested subject. These individuals have been under observa-
tion for a period of two months. Our data show that very little
variation has occurred. Subject D.P. has had constantly a count
of 1 or 2 ova per slide since the beginning of the study. Subject
M.P. has varied between 12 and 16 ova per slide. Subject B.P.
had an ova count of 23 to 26 for a period and then the count in-
creased to 39 to 45. This count has been constant for four weeks.







Forty-fifth Annual Report, 1931


HORTICULTURE
REFRIGERATION STUDIES
The cold storage plant, which was started during the fiscal
year 1929-30, was largely completed by December, 1930, with the /
exception of some changes and adjustments that have had to be
made in the operation of the plant since that time. The plant as
finished contains six experimental cold storage rooms, each with
a capacity of approximately 1,000 cu. ft. and each one under au-
tomatic temperature control, using a closed bunker system with
blower operated by the room thermostat. The bunkers are cooled
by means of brine circulated from the brine tank and are con-
trolled at approximately 4 below room temperature by means of
a Fulton sylphon valve. The transfer of air to the room is
made by means of a blower fan operated by the room thermostat
and when the fan is off the opening is automatically closed by
means of a shutter. The range of control is approximately 1 F.
The rooms were put into operation at the following temperatures:
300, 36, 42, 480, 54, and 600 F. During the winter months it
was necessary to add at times a small amount of heat to the
rooms at 540 and 600 when outside temperatures fell so low as to
bring the outside temperature below the specified room tempera-
ture.
In addition to the experimental cold storage rooms, two freez-
ing storage rooms were provided, one for operation at 0 F. and
one for operation at 100 F. These rooms are cooled by direct ex-
pansion rather than by means of the brine system.
In the spring of 1931, it was found necessary to install a quick
freezer which would be suitable for experimental work and at
the same time have a considerable capacity. For this purpose a
shell and tube brine cooler was utilized in connection with a small
brine tank 2 ft. wide, 4 ft. long and 1 ft. deep. A small brine
pump served for brine circulation and the equipment was put in
so as to utilize it with either the small or the large compressor by
hand operation. In ordinary operation, the amount of brine in
the system does not exceed 30 gallons and the equipment is very
flexible in that the temperature can be brought down very quickly
to the desired point but, owing to the small brine capacity, ac-
curate control is somewhat difficult, this latter point being over-
balanced by the quickness with which the equipment can be
brought down to the required temperature.
Containers are frozen immersed in brine. Those that have lids






Florida Agricultural Experiment Station


that might leak are immersed to the lid by inserting them in
holes in a metal plate which is kept at the level of the brine sur-
face, the holes in the plate catching the lid or the shoulder where
the lid fits. Four and 6-oz. containers can be frozen easily in 30
minutes at temperatures around -20 F. and larger containers
in proportionately more time. Freezing in this way has been
found to produce an excellent frozen product in that the crystals
are very small and separation of the solids very slight.
A large amount of experimental work was carried out in this
plant during the latter part of the fiscal year and this work was
of an exploratory nature preliminary to the laying out of projects.
Some of the results of these experiments are given in this report.
Several experiments on grapefruit storage were carried out.
Pitting of grapefruit was found to be closely allied with tempera-
ture. Of the temperatures used, 420 F. seemed to produce the
maximum amount of pitting, although there was almost as much


Fig. 2.-Cross-section of Marsh Seedless grapefruit from cold storage ex-
periments, showing internal breaking down due to pressure in packing.







Forty-fifth Annual Report, 1981


at 360. At 480 F. no pitting at all appeared in some lots of fruit
and a very slight pitting, of no commercial importance, appeared
in one or two lots of fruit. At 300 F. no pitting occurred, except
an occasional very light-colored pit which did not injure the fruit
for commercial purposes. The fruit softened excessively, how-
ever. Generally speaking, of the temperatures used, 480 F.
seemed to be most favorable to the fruit itself, in that pitting
was prevented and the fruit kept in normal shape. Decay was
very high, however, and, unless this could be controlled, this tem-
perature would be too high for commercial storage and some
means would have to be taken to overcome pitting at the lower
temperatures.
An internal breakdown such as is illustrated in Fig. 2 occurred
in all lots of grapefruit that were packed with a bulge pack and
put in storage under pack or after having been packed for some
time. This breakdown occurs in the pulp when the fruit has been
flattened due to pressure, and is probably due to the pressure put
on the fruit by the bulge pack. The flattening of the fruit breaks
up the delicate tissue underneath the rind and results in a drying
out and disintegration. This breakdown was extremely bad in
a lot of Marsh Seedless and is probably aggravated by the fact
that the center of the fruit is open and the fruit consequently
does not have the same outward resistance that a fruit of the
seedy type has. This breakdown of Marsh Seedless was, at the
end of one month, so extensive as to make the fruit undesirable
commercially. The flattened spots were soft and, on cutting, re-
vealed a broken-up mass of tissue that had the appearance of
decay but was not actually infected. A soft decay which gave
the decayed area a sort of semi-transparent appearance was
found at 360 and 300 F., and attention of the Plant Pathology De-
partment called to it. On examination, it was found to be due to
blue mold but there was no surface sporulation and the fruit
would go completely soft without spores forming.
Experiments were carried on by one of the graduate students
on various types of wrappers for oranges. Cellophane and alum-
inum foil were found to decrease greatly the amount of water
lost from the fruit as compared with paper, waxed paper, parch-
ment or oiled paper wraps. The fruit under such conditions kept
in a more natural condition than did the fruit under any of the
paper wrappers, in that shriveling and drying was prevented. In
one lot of Pineapple oranges, however, in which no aluminum
foil was used, the cellophane appeared to increase the amount of







Florida Agricultural Experiment Station


decay over that found in the paper wraps. This work is being
continued on a large scale.
Sweet potatoes from the College of Agriculture storehouse
which had started to sprout in the spring were placed in storage
at all the ordinary temperatures and were found to keep until
summer in first-class condition in the 540 and 600 F. rooms and
the sprouting was stopped. At 48 F. the fruit kept less well
and by July 1 was showing about 50% softening. Potatoes at
420, 360 and 300 F. softened very quickly. A temperature be-
tween 540 and 600 F. would seem to be highly satisfactory and is
in line with other experimental work.
In all storage work with grapefruit and oranges, the amount of
decay was excessive and arrangements are being made with the
Plant Pathology Department for cooperative work along this line.
A large number of experiments were carried on with frozen
orange juice and the decision was reached that paper containers
of the type now available are not highly suited to experimental
work, in that too many variables are presented which may have
an effect upon the keeping quality of the juice. With this in
mind, provision has been made for freezing in glass, capping
either under vacuum or under various gases, and in enameled tin
capped under vacuum or any gases desired.
This equipment was put in at the end of the fiscal year and was
not used extensively during the current season. Preliminary ex-
periments with it, however, have been highly satisfactory. The
ordinary type of glass tumbler was found to freeze in brine with-
out breakage. The experiments with orange juice indicated the
importance of removal of air from the product and the rapid
freezing of the product in order to prevent heavy precipitation of
solids on thawing, giving a juice in which the solids have a curdy
appearance. This has been found to be remedied by rapid freez-
ing or by jarring or rotating the container during the period of
freezing. Material was frozen rapidly at a temperature of -15 F.
Extensive experiments are planned for the coming season on
frozen orange juice. Tangerine juice was found to keep well un-
der frozen storage and to be more easily handled than orange
juice from that standpoint. In trials it was favored over orange
juice practically without exception. It is thought that it would
be more highly adapted to soda fountain use than to home use, as
it is too sprightly for a breakfast drink. Tangelo juice was also
found to be very satisfactory and to stand up well under frozen
storage.






Forty-fifth Annual Report, 1931


The freezing of fruits other than citrus was tried out as ex-
tensively as possible and Youngberries were found to be unusu-
ally well adapted to freezing. Youngberries put up in either 25
or 30 percent syrup and frozen kept their shape well, lost a mini-
mum of material to the syrup and had a marked raspberry flavor
when fully thawed. All those sampling the product found it very
desirable and the deterioration due to contact with air or con-
tainer was very small.
Florida Missionary strawberries frozen in 371/ % syrup in less
than one hour retained their original appearance on thawing, with
only a slight softening. The color was that of the fresh berry.
It is believed that this product may have considerable value for
very high-grade preserves and similar products, as the berry is
much more natural in appearance than is the ordinary cold-pack
strawberry.
Plans are under way to carry on this line of work very ex-
tensively during the coming season.


FUNDAMENTAL PHYSIOLOGY OF FRUIT PRODUCTION
State Project No. 111 A. F. Camp, Leader

Due to the large amount of time necessary in getting the cold
storage project under way, work on this physiology project was
largely held up during the fiscal year. However, some experi-
ments were carried out.
A careful chemical study was made of oranges and grapefruit
from rough lemon and sour stocks. The fruit used in this experi-
ment came from the Lake Alfred Station from the rootstock ex-
periment. The trees were of the same age and in adjoining rows
and subject to exactly the same treatment. In addition to this,
the original buds of each variety came from the same tree. The
fruit from the rough lemon stock was found to be lower in sugar,
acid and solids than that from sour orange stock throughout the
season. This work is being continued.
The study of the effect of soil temperature on the germination
of citrus seeds was continued, and extensive experiments were
run with sour orange, rough lemon, grapefruit and sweet orange.
The optimum of germination was found to be between 30 and 35
degrees Centigrade and the upper limits for germination of
growth below 400 C. The results of these experiments are now
being compiled for publication.







Florida Agricultural Experiment Station


OBSERVATION AND TESTING OF VARIOUS CITRUS HYBRIDS
Hatch Project No. 51 Harold Mowry, Leader

No additions have been made to the citrus hybrid plantings
and none of the older ones have fruited other than those previous-
ly reported. As the fruit of most of the hybrids having Poncirus
trifoliata parentage are inedible, present work with these is being
confined mainly to the determination of their adaptability and
value as rootstocks.

TESTS OF DIFFERENT STOCKS AS ROOTSTOCKS FOR SATSUMA
ORANGES
Hatch Project No. 81 Harold Mowry, Leader

On like soils and under the same cultural treatment, Satsuma
scions on the Rusk citrange rootstock continue to show a superi-
ority in growth and cold-resistance over those worked on other
rootstocks.
Little or no difference is apparent in the type or the rate of
growth in 7-year trees of the Wase and Owari varieties budded
on P. trifoliata rootstocks.

RELATION OF NITROGEN ABSORPTION AND STORAGE TO GROWTH
AND REPRODUCTION IN CITRUS AND PECANS
Adams Project No. 165 A. F. Camp and G. H. Blackmon,
Leaders
Citrus
Work on this project was started early in the year and citrus
seedlings were grown in Hoagland's solution and a modified Hoag-
land's solution in which half of the nitrogen was furnished as the
ammonium radical. At first the seedlings in the unmodified so-
lution made the best growth, but later these developed a marked
boron deficiency and those in the solution in which part of the
nitrogen was furnished as ammonium surpassed them. Some of
the plants showing boron deficiency were treated with traces of
boron and made a marked recovery.
The root systems of the plants in the modified solution were
very much thickened and shortened and very scant as compared
to those in the unmodified solution. It is probable that this is
due to the solution being too acid, though very small differences
were found when pH determinations were made. This work is
being continued.






Forty-fifth Annual Report, 1931


Pecans
The first series of pecan seedlings were placed in Hoagland's
nutrient solution, but there was no growth response at all. The
roots blackened and the plants died.
The second lot of seedlings were placed in 20 representative
solutions of the 84 Tottingham series. These are being run paral-
lel with the same number of solutions in which ammonium sulfate
is substituted for potassium nitrate. No conclusions can be made
at this time.

VARIETY RESPONSE OF PECANS TO DIFFERENT SOIL TYPES,
LOCALITIES, ETC.
State Project No. 46 G. H. Blackmon, Leader
There is a general tendency on the part of growers to confine
pecan plantings to three or four varieties. These will vary with
the locality but Stuart and Success are included in most of the
late plantings, the other one or two being selected from Money-
maker, Moore, Curtis, Kennedy, Schley, and a few others.
The behavior of varieties previously reported has been noted
during the year.
Austrian winter peas and hairy vetch are planted in many or-
chards as a winter cover, and Crotalaria spectabilis as a summer
cover crop.

COOPERATIVE FERTILIZER TESTS IN PECAN ORCHARDS
State Project No. 47 G. H. Blackmon, Leader
Owing to a very severe infestation of nut case-bearer in 1929,
prospects for a heavy crop of nuts did not materialize. However,
in most of the experiments there was a fairly good production
of nuts and the fertilized trees generally gave a much better yield
than the unfertilized ones.
Tree growth in most instances was greater in fertilized plots
than in unfertilized ones. The growth is determined by girth
measurements taken during the early spring of each year. In
this connection it should be stated that the area of the cross-sec-
tion has been used instead of the circumference of tree trunk.
This has been found a much more accurate indication of growth
than where the girth only is used.
During the drouth of May and June of 1931 the trees receiving
6 percent ammonia and more had a darker green foliage and
made a better twig growth than those receiving 4 percent and less.







Florida Agricultural Experiment Station


VARIETY AND STOCK TESTS OF PECAN AND WALNUT TREES
State Project No. 48 G. H. Blackmon, Leader

The trees in the variety orchard have made a satisfactory
growth during 1930. There is a light set of nuts on many of the
trees this year.
The western varieties that show extreme susceptibility to
pecan scab are Cline, Harbin, Sims, and Sovereign.
The average green weight of Crotalaria spectabilis on Septem-
ber 20 was 25,600 pounds per acre. This material was cut into
the soil with a tractor disk on September 22. The soil was planted
to Austrian winter peas in October. The green material, which
averaged 9,800 pounds per acre, was disked into the soil in April.

COOPERATIVE COVER CROP TESTS IN PECAN ORCHARDS
State Project No. 80 G. H. Blackmon, Leader

There was a fairly good set of nuts on the bearing trees included
in this project growing in the winter legume plots and a some-
what lighter nut set on the trees in the winter non-legume and
check plots. While the bloom and set were satisfactory, a very
light yield was harvested due to the severe infestation of the nut
case-bearer which destroyed almost all of the crop. All of the
nuts, with the exception of a very few pounds, were produced by
the trees in the winter and summer legume plots.
The Crotalaria spectabilis in the two experiments in Jefferson
County average 9,700 and 11,500 pounds of green weight per acre,
respectively.
Monantha vetch produced the greatest tonnage of green ma-
terial, there being 33,000 pounds per acre, while hairy vetch and
Austrian winter peas produced 32,000 and 28,000 pounds, respec-
tively.
A pecan planting has been made on the Experiment Station
farm to be used in connection with this project.

REJUVENATION EXPERIMENTS WITH NEGLECTED PECAN
ORCHARDS
State Project No. 164 G. H. Blackmon, Leader

The trees included in this project are making satisfactory
growth. There was a very light yield of nuts, largely due to in-
sect damages.






Forty-fifth Annual Report, 1931


FIELD STUDIES OF THE DISEASES AFFECTING THE PECAN,
INCLUDING CONTROL MEASURES
State Project No. 44 G. H. Blackmon, Leader
This project is being dropped from its listing in the Horticul-
tural Department. All work on pecan diseases is being conducted
by the Plant Pathology Department.

FIELD STUDIES OF THE INSECTS ATTACKING THE PECAN,
INCLUDING CONTROL MEASURES
State Project No. 45 G. H. Blackmon, Leader
This project is being dropped from its listing in the Horticul-
tural Department. All work on insect pests of pecans is being
conducted by the Entomology Department.

TESTING OF NATIVE AND INTRODUCED SHRUBS AND ORNA-
MENTALS AND METHODS OF THEIR PROPAGATION
Hatch Project No. 52 Harold Mowry, Leader

Tree's not common in Florida which are making a thrifty
growth include the cork oak, Quercus suber, maidenhair, Ginko
biloba, and the Moline and Chinese elms, Ulmus spp. The blight-
immune chestnut, Castanopsis delavayi, apparently is not adapted.
The blossoms of the Japanese ornamental flowering Prunus
species are unusually attractive, making the plants of value as
ornamentals wherever they may be adapted. Results of several
years' growth with several varieties have been as follows:
Fairly Thrifty No Thrift or Dead
Prunus serrulata-Shirofugen P. serrulata-Fukurokuju
Prunus yedoensis-Yoshino P. serrulata-Senriko
P. serrulata-Naden
P. serrulata-Fugenzo
P. serrulata-Mikururmagaeshi

VARIETY, PROPAGATION AND PLANTING TESTS OF PEAR,
AVOCADO, JAPANESE PERSIMMON, FIG AND OTHER FRUITS
Hatch Project No. 58 Harold Mowry, Leader

Of 21 varieties of plums planted in 1926 few have shown a de-
gree of adaptability that would make them of value for either
home or market planting. The tests were made on Norfolk soils.
Native wild plum, Prunus americana, trees were interplanted
as an aid in pollination to those varieties blossoming during the







Florida Agricultural Experiment Station


same period. After five seasons' growth the varietal adaptability
has been as follows:


Thrifty Growth
Excelsior
Kelsey
*"Samonii"
*Satsuma
*"Texas" (unknown origin)
Wickson


Apparently Not Adapted; Poor Growth
or Dead
Abundance
*Burbank
*Chabot
*Italian Prune
*McRae
*Red June
*Terrell
*Prunus ansu
*Prunus bokhariensis
*Prunus glandulosa
*Prunus hortulana
*Prunus salicina (Jap. plum)
*Prunus salicina (Wright's Early)
*Prunus salicina (Alpha)
sp. FPI 47935 (hybrid)


Two of the later Japanese persimmon introductions, FPI 58971
and 58972, have fruited. The former is of large size, tomato-
shaped-some fruits nippled at apex; 10 seeds; pollination con-
stant; light-fleshed; soft; astringent until ripe; quality good.
Prolific. Ripens late October. The tree of the latter resembles
the Tamopan variety in foliage and uprightness. Fruit medium
in size; constricted irregularly near stem end; partially quadran-
gular in shape, some with four distinct longitudinal indentations
or creases; pollination constant; few seeds; light-fleshed; sweet;
quality akin to Tamopan. Prolific. Ripens late October and
early November.
Several Mexican avocado seedlings are fruiting. One last sea-
son produced fruit of very good quality and of fair size, the av.
erage weight being one-half pound and the length 41/2 to 5 inches.
The ripening season is in late August.
In the older pear plantings, the growth of the varieties has been
as follows:


Good
tChinese Sand (Pineapple)
Conkleton
tHood


Fair
t"Good Christian"
**LeConte
**Keiffer
**Garber


Poor
**Mendel
t"Unknown No. 1"
Harbin
Mugden


Several other hybrids and varieties have not yet reached an age
that would definitely determine their adaptability and blight re-
sistance.
On the Station test grounds it has not been possible to secure

*Have not fruited
tSome blight infection. **Severe blight infection.







Forty-fifth Annual Report, 1931


a growth in blueberry, Vaccinium virgatum, plants comparable
to that in the northwestern section of the state. The plants lack
in vigor and after four years in the field, with ample cultural at-
tention, none has attained a height exceeding 31,/ feet.

VARIETY TEST OF GRAPES
Hatch Project No. 49 Harold Mowry, Leader
There have been no material changes in the results of the va-
riety test from those reported last year. Additions have been
made to the planting for the purpose of determining results that
may be had from different methods of pruning.

VARIETY TEST OF BERRIES
Hatch Project No. 59 Harold Mowry, Leader
During the past seven years several varieties and species of
berries (Rubus) have been grown on the test grounds. The soils
in the test plots are of the Norfolk series. A summation of the
results is given below:
Best Fair Poor or Worthless
Marvel Dallas Blowers
Advance Manatee Cory Thornless
McDonald Early Harvest
Ness Eldorado
Young Erie
"Oregon" Haupt
Himalaya
Lucretia
Mays (Austin)
Mercereau
Rathbun
Robison
Snyder
Thornless Austin
Rubus ellipticus
Rubus fraxinifolius
Rubus glaucus
Rubus macrocarpus
Rubus niveus

Blackberry plants grown from root cuttings taken from plants
of the Marvel variety infected with the double-blossom disease
and from plants showing no evidence of the disease were planted
in parallel rows 8 feet apart. After three years all except two
of the plants grown from infected plants showed infection. None
of those from disease-free plants showed evidence of the disease.
Although not as yet conclusive, this would show that at least
temporary freedom from the disease may be had by taking root
cuttings only from plants which have fruited and shown no dou-






Florida Agricultural Experiment Station


ble-blossom for several seasons. Seedling plants of the Marvel
variety have shown no more resistance than plants gathered from
random sources.
PROPAGATION, PLANTING, AND FERTILIZING TESTS WITH
TUNG-OIL TREES
Hatch Project No. 50 Harold Mowry, Leader
Seedling trees of Aleurites montana in their seventh year, al-
though growing vigorously, continue to bear little or no fruit. A
budded tree, on A. fordi rootstock, is fruiting prolifically.
Hybrid trees of A. fordi x A. montana are making a vigorous
growth but do not surpass thrifty trees of either parent. The
hybrids in their vegetative characteristics strongly resemble A.
montana, the male parent. They have not yet fruited.
A cooperative experimental planting comprising 38 test plots
has been included in the investigational work with the tung-oil
tree. These experimental plantings include comparative tests of:
Budded and seedling trees of two tree types.
Severe pruning (cutting back) and no pruning at time of trans-
planting.
Close and wide spacing in field planting.
One, two, and three year nursery stock for field planting.
Mulching and clean culture.
Field-grown seedlings (no transplanting) and transplanted
nursery stock.
Cover crops-four kinds.
Fertilizers, embracing eight sources of organic and seven of
inorganic nitrogen, alone or in mixtures of varying quantity.
AVOCADO MATURITY STUDIES
Purnell Project No. 139 A. L. Stahl, Leader
Work on this project was continued in a similar manner to that
of the previous season. A detailed study was made throughout
the entire growth cycle of the fruit of the changes taking place
in the composition of twelve important Florida avocado varieties
grown in three different sections of the state.
In an effort to find some better and easier method of testing
maturity or ripeness in the avocado than the oil content method,
a complete analysis of the fruit was made, including specific grav-
ity; moisture; oil and fat; total sugar; protein; crude fiber; ash;
percent of seed, skin and edible pulp; and pressure tests. Many
interesting and valuable results were obtained.
The fruit of all varieties tested shows a very small oil and fat




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