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














Group Title: Annual report, University of Florida. Agricultural Experiment Station.
Title: Annual report for the fiscal year ending June 30th ...
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Permanent Link: http://ufdc.ufl.edu/UF00027385/00023
 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: 1937
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: VID00023
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
    Credits
        Page 2
    Letter of transmittal
        Page 3
        Page 4
    Main
        Page 5
        Page 6
        Page 7
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    Index
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Full Text









GAINESVILLE, FLORIDA



AGRICULTURAL EXPERIMENT

STATION




Annual Report
FOR THE FISCAL YEAR ENDING
June 30, 1937








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
Harold Mowry, M.S.A., Asst. Dir., Adm.
J. Francis Cooper, M.S.A., Editor
Jefferson Thomas, Assistant Editor
Clyde Beale, A.B.J., Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager
K. H. Graham, Business Manager
Rachel McQuarrie, Accountant

MAIN STATION, GAINESVILLE
AGRONOMY
W. E. Stokes, M.S., Agronomist**
W. A. Leukel, Ph.D., Agronomist
G. E. Ritchey, M.S.A., Associate*
Fred H. Hull, Ph.D., Associate
W. A. Carver, Ph.D., Associate
John P. Camp, M.S., Assistant
Roy E. Blaser, M.S., Assistant
ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Animal Husbandman**
R. B. Becker, Ph.D., Dairy Husbandman
L. M. Thurston, Ph.D., Dairy Technician
W. M. Neal, Ph.D., Asso. in An. Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian
N. R. Mehrhof, M.Agr., Poultry Husbandman
W. W. Henley, B.S.A., Asst. An. Husb.*
W. G. Kirk, Ph.D., Asst. An. Husbandman
R. M. Crown, M.S.A., Asst. An. Husbandman
P. T. Dix Arnold, B.S.A., Assistant Dairy
Husbandman
L. L. Rusoff, M.S., Laboratory Assistant
Jeanette Shaw, M.S., Laboratory Technician
CHEMISTRY AND SOILS
R. V. Allison, Ph.D., Chemist**
R. W. Ruprecht, Ph.D., Chemist
R. M. Barnette, Ph.D., Chemist
C. E. Bell, Ph.D., Associate
R. B. French, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant
ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural Economist**
Bruce McKinley, A.B., B.S.A., Associate
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Assistant
ECONOMICS, HOME
Ouida Davis Abbott, Ph.D., Specialist**
C. F. Ahmann, Ph.D., Physiologist
ENTOMOLOGY
J. R. Watson, A.M., Entomologist**
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist and
Acting Head of Department
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Horticulturist
R. J. Wilmot, M.S.A., Specialist, Fumigation
Research
R. D. Dickey, B.S.A., Assistant Horticulturist
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist**
George F. Weber, Ph.D., Plant Pathologist
R. K. Voorhees, M.S., Assistant
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Assistant Botanist
Stacy O. Hawkins, M.A., Assistant Plant
Pathologist
SPECTROGRAPHIC LABORATORY
L. W. Gaddum, Ph.D., Biochemist
L. H. Rogers, M.A., Spectroscopic Analyst


BOARD OF CONTROL

Geo. H. Baldwin, Chairman, Jacksonville
Oliver J. Semmes, Pensacola
Harry C. Duncan, Tavares
Thomas W. Bryant, Lakeland
R. P. Terry, Miami
J. T. Diamond, Secretary, Tallahassee

BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY
L. O. Gratz, Ph.D., Plant Pathologist in
Charge
R. R. Kincaid, Ph.D., Asso. Plant Pathologist
J. D. Warner, M.S., Agronomist
Jesse Reeves, Farm Superintendent
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Horticulturist in Charge
John H. Jefferies, Superintendent
W. A. Kuntz, A.M., Asso. Plant Pathologist
Michael Peech, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Asst. Entomologist
Walter Reuther, B.S., Asst. Horticulturist
EVERGLADES STATION, BELLE GLADE
A. Daane, Ph.D., Agronomist in Charge
R. N. Lobdell, M.S., Entomologist
F' D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Physiologist
G. R. Townsend, Ph.D., Assistant Plant
Pathologist
J. R. Neller, Ph.D., Biochemist
R. W. Kidder, B.S., Asst. Animal Husbandman
W. T. Foresee, Ph.D., Asst. Chemist
B. S. Clayton, B.S.C.E., Drainage Engineer*
SUB-TROPICAL STATION, HOMESTEAD
H. S. Wolfe, Ph.D., Horticulturist in Charge
W. M. Fifield, M.S., Asst. Horticulturist
Geo. D. Ruehle, Ph.D., Asso. Plant Pathologist
W. CENTRAL FLA. STA., BROOKSVILLE
W. F. Ward, M.S.A., Asst. An. Husbandman
in Charge*

FIELD STATIONS
Leesburg
M. N. Walker, Ph.D., Plant Pathologist in
Charge
W. B. Shippy, Ph.D., Asso. Plant Pathologist
K. W. Loucks, M.S., Asst. Plant Pathologist
J. W. Wilson, Ph.D., Associate Entomologist
C. C. Goff, M.S., Assistant Entomologist
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
Cocoa
A. S. Rhoads, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
Monticello
Sam O. Hill, B.S., Asst. Entomologist*
Bradenton
David G. Kelbert, Asst. Plant Pathologist
Sanford
E. R. Purvis, Ph.D., Assistant Chemist,
Celery Investigations
Lakeland
E. S. Ellison, Meteorologist*
B. H. Moore, A.B., Asst. Meteorologist*
In cooperation with U.S.D.A.
** Head of Department.











LIST OF DEPARTMENT REPORTS
Page
R report of D director .................... ..... ........... ....... ..... ............... .. ............. 5
Report of Business Manager ........... ...................... ......................... .... .... 14
Editorial and M ailing Departm ent ........................................................................ .................. 22
Library ...................................... .. ....................... ...................... ............... ... 29
Agricultural Economics ................................... ........... ........ ...... .......... 30
Agronomy .................... .......................................-- 35
A nim al H usbandry ................................. ........... ........................................ ............. ........ 50
Chem istry and Soils ....................... ................................................................... ................. ..... 6
H om e E conom ics ......................... .............. ........................................... .. ... 75
H horticulture .................... ................ ...... ............................................................... 78
P lant P anthology .................................... ....................................... ......... ....................... ........ 93
Spectrographic Laboratory ...,.................. ................................. ......... ....................... ..... 113
Federal-State Horticultural Protection Service ............................................. ...... 115
Citrus Station ........................................... .................................... ................... ............... 122
E verglades Station ........................ ....................................... ................... .... ..-............ 137
N north Florida Station ............................ ......... ............................ ................ ..... 160
Sub-Tropical Station ........................................ ......................... .............. ..... . .... 171
W est C central F lorida Station ...................... ....................................................................................... 179









Hon. Fred P. Cone,
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 Experiment Stations
for the fiscal year ending June 30, 1937.
Respectfully,
GEORGE H. BALDWIN,
Chairman, Board of Control.








Hon. George H. Baldwin,
Chairman, Board of Control

SIR: I have the honor to transmit herewith the annual report of the
Director of the University of Florida Agricultural Experiment Stations
for the fiscal year ending June 30, 1937, 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.










Golden Anniversdry

of the Florida Agricultural Experiment Sta-
tions will be celebrated in 1938. Established
at Lake City in 1888, transferred to Gaines-
ville in 1905-06, for 49 years the institution
has been


Serving Florida larming

Its investigators have made notable achieve-
ments during half a century of delving into
the realm of the unknown and emerging with
the practical. Estimates have been made
that the Station's research is saving and
earning 25 million dollars annually for Flor-
ida farmers.



UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
WILMON NEWELL, Director
GAINESVILLE, FLORIDA









Report for the Fiscal Year Ending

June 30, 1937







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 Sta-
tions, together with the reports of the heads of the several departments,
for the fiscal year ending June 30, 1937.
Respectfully,
WILMON NEWELL,
Director.






During the past fiscal year the work of the Experiment Stations has
been substantially along lines inaugurated previously. In addition to
Main Station activities, comprising the work of nine research depart-
ments, specialized lines of investigations have been continued at the four
branch stations and eight field laboratories. A detailed review of the work
and progress of each of the several departments and field stations is
given under their respective headings on the following pages.
IMPROVEMENTS AND LAND ADDITIONS
At the Main Station a tract of farm land of some 91 acres was added
to holdings adjoining University properties. Construction was nearly com-
pleted at the end of the year on the dairy products laboratory building-- ,
a Public Works Administration project.
A laboratory building and a small greenhouse unit were erected at
Hastings. Land for the site-1 acre-was donated by the Hastings Potato
Growers' Association.
An addition to the laboratory building was completed which greatly
enlarges the working space and facilities of the Citrus Experiment Station.
RANGE CATTLE BRANCH STATION
The 1937 Legislature (Chapter 18562-No. 856) authorized the estab-
lishment of a branch experiment station in Hardee County for the purpose
of conducting research in the production of livestock and the improvement
of pasturage.
No funds were appropriated for carrying out the provisions of the Act.







Florida Agricultural Experiment Station


CHANGES IN STAFF
L. M. Thurston was appointed Dairy Technologist July 1, 1936.
Walter Reuther was appointed Assistant Horticulturist, Citrus Experi-
ment Station, July 1, 1936.
Warren O. Johnson, Alfred L. Lorenz, Ray T. Sherouse, and Leonard G.
Pardue, Jr., were appointed Assistant Meteorologists November 1, 1936.
Roy E. Blaser was appointed Assistant Agronomist January 15, 1937.
Sam O. Hill was appointed Assistant Entomologist, Pecan Insect In-
vestigations, February 1, 1937.
R. V. Allison was appointed Chemist and Head of Department of Chem-
istry and Soils, March 1, 1937.
W. T. Foresee was appointed Assistant Chemist, Everglades Experiment
Station, April 19, 1937.
Margaret Crown, Mailing Clerk, died May 27, 1937.

FINANCIAL RESOURCES
Financial resources, from both Federal and State appropriations, of
the Agricultural Experiment Stations for the fiscal year ending June 30,
1937, were as follows:
Federal Hatch and Adams funds ...-------............ ........................$ 30,000.00
Federal Bankhead-Jones funds .....--------...-.... --.........---..---. 15,400.82
State funds
Main Station .............................----------------- ---------.------ 265,368.11
Including Bankhead-Jones offset and field
laboratories as follows:
Bankhead-Jones offset ..........................................$19,646.80
Tomato Disease Investigations, Bradenton ...... 3,011.50
Strawberry Investigations, Plant City ............ 6,365.43
Citrus Disease Investigations, Cocoa ................ 3,510.06
Potato Disease Investigations, Hastings .......... 4,006.65
Laboratory at Hastings ----...................................... 10,500.00
Pecan Insect Investigations, Monticello ............ 5,989.08
Celery Investigations, Sanford ............................ 5,253.83
Fumigation Research ............................................ 3,072.27
Grape Pest Investigations .................................... 3,505.51
Citrus Experiment Station, Lake Alfred ........................................ 55,740.93
Everglades Experiment Station, Belle Glade ................................ 50,961.96
North Florida Experiment Station, Quincy .................................... 26,045.18
Subtropical Experiment Station, Homestead ................................ 10,590.93
Watermelon Laboratory, Leesburg ...........................-----------------. 7,094.57
Frost Forecasting Service, supplementing Federal funds .......... 12,955.24
Other Federal funds, not included above .......................................... 60,000.00

RANGE OF RESEARCH ACTIVITIES
All regular lines of research are carried and classified under specific
projects. The project list for the year, covering the investigations of
the various departments and branch stations, was as follows:




LIST OF PROJECTS UNDER INVESTIGATION DURING THE YEAR


Department
AGRICULTURAL
ECONOMICS







AGRONOMY


Number Title Page
73 Agricultural Survey of Some 500 Farms in the General Farming Region of North-
w est F lorida .......................... .................... ...... ..................................... 30
154 Farmers' Cooperative Associations in Florida ........................................... ........... .......... 30
186 Cost of Production and Grove Organization Studies of Florida Citrus ........................ 30
235 A Study of Pre-Cooling and of Refrigeration in Transit as Affecting Cost of
Marketing, Quality and Price of Citrus Fruit ...................---.............---- ........-- 33
262 A Study of Adjustments in Farming by Regions and Type-of-Farming Areas,
from the Standpoint of Agricultural Adjustment and Planning, Including
Soil Conservation -- .... .......... .......................... ........... ................................... 34
20 Peanut Im provem ent .......... ... .. ......------ .... ...............---- ........... .................. 35
27 Pasture E xperim ents ........................................ ................ ................ ................................ 35
27A Value of Centipede Grass Pastures as Affected by Soil Characteristics and Other
F actors ... . ..... .................... ... ... ............ ................ ..... .............. ............................... 36
55 Crop Rotation Studies with Corn, Cotton, Crotalaria and Austrian Peas .-.............. 36
56 Variety Test Work with Field Crops --------.......--------.....-... --......---............................ 37
98 Green Manure Studies .......-.. -..-- -------- ------.........-.-........-.-. ........-................. ....--.....- 39
105 Improvement of Corn by Selection and Breeding -----....................- ......................... 39
120 Fertilization of Pasture and Forage Grasses ........................ ........ .......................... 40
163 Corn Fertilizer Experim ents ..--.. .................. ...................... ......... .......... ................. 41
174 A Study of Crotalaria as a Forage Crop ........................... ....................................... 42
220 A Study of "Chlorosis" in Corn Plants and Other Field Crop Plants ........................ 42
243 A Study of the Development and Deterioration of Roots in Relation to the Growth
of Pasture Plants Grown Under Different Fertilizer and Cutting Treatments 42
265 Composition Factors Affecting the Value of Sugarcanes for Forage and Other
Purposes .--- .-- .- ............... ... ......... ......................... 42
267 Pasture Studies ...---..-..-- ..---......-......-......... .... ..-...................-. ....--.......................--........... 43
295 The Effect of Fertilizers on the Yield, Grazing Value, Chemical Composition and
Botanical Make-up of Pastures ............................. -----................... 43
296 Eradication of W eeds in Tame Pastures ................................... .................................. 44
297 Forage Nursery and Plant Adaptation Studies ....................... ............................... 44
298 Forage and Pasture Grass Improvement --.................................................................... 45
299 Growth Behavior and Relative Composition of Range Grasses as Affected by
Burning and the Effect of Burning on Maintenance of Natural Grass Stands
and Upon the Establishment of Improved Grasses ........................................... 45
300 Methods of Ridding Land of Objectionable Growths aad Obstacles ............................ 46









Department
AGRONOMY
(Continued)



ANIMAL
HUSBANDRY


Number


Title


Page


Pasture Legumes ..--- -- ------------------------- -------------------
A Study of Napier Grass for Pasture Purposes ............. .................. .......
Water Pasture Studies ...-...............-------.....-----------------
Method of Establishing Permanent Pastures Under Various Conditions ................
Spacing and Plant Competition in Common Field Crops .......................................
Deficiencies in Feeds Used in Cattle Rations ................--- ...... ---.-----------
Relation of Conformation and Anatomy of the Dairy Cow to Her Milk and
Butterfat Production .................-................ ...........
A Study of the Feeding Value of Crotalarias ..............................................
A Study of the Ensilability of Florida Forage Crops -....----.....--...-........-...-----
Beef Cattle Breeding Investigations ...-....................---...............
Cooperative Field Studies with Beef and Dual-Purpose Cattle ...................---......--
Beef and Dual-Purpose Cattle Investigations ..................------.. ..... ----
Investigations of Hemorrhagic Septicemia in Cattle and Swine ................................
The Digestible Coefficients and Feeding Value of Dried Grapefruit Refuse and
Dried Orange Refuse ........................................ .............
The Efficiency of the Trench Silo for Preservation of Forage Crops as Measured
by Chemical Means and by the Utilization of the Nutrients of the Silage
by Cattle ..................
A Comparative Study of Corn and Liquid Milk Versus a Grain and Mash Ration
in Feeding for Egg Production ...................................................................
A Comparative Study of the Value of Meat Scraps, Fish Meal, and Milk Solids
as Sources of Protein for Egg Production .............................................. ..
Lights Versus No Lights for Egg Production on Single Comb White Leghorn
Pullets and Hens ..................... ..........................................................------------- -
The Etiology of Fowl Paralysis, Leukemia and Allied Conditions in Animals ........
A Study of Plants Poisonous to Livestock in Florida ........................................
Studies in Fleece and Mutton Production ....................................................... ...
A Statistical Study of the Relationship Between Temperature and Egg Weight
(Size), Body Weight and Egg Weight, Body Weight and Production, Age
and Egg Weight of Single Comb White Leghorn Pullets .............................
Utilization of Citrus By-Products for Poultry ....................................... ....
Poultry Breeding ......................................................
Deficiencies of Peanuts When Used as a Feed for Swine ........................................
Method of Handling Sows and Young Pigs .................................... .--
The Utilization of Citrus Meal as Swine Feed ..................-.............. ......




Department Number Title Page


CHEMISTRY
AND SOILS










ENTOMOLOGY







HOME ECONOMICS






HORTICULTURE


Determination of the Effect of Various Potash Carriers on the Growth, Yield and
Com position of Crops ..... ... .. .....................................................................
The Effect of Various Fertilizer Formulas .............. ................................
Determination of the Effect of Green Manures on the Composition of the Soil ........
A Study of "Chlorosis" in Corn Plants and Other Field Crop Plants ........................
Bronzing or Copper Leaf of Citrus ... ...... ...............................................
The Occurrence and Behavior of Less Abundant Elements in Soils ............................
Soil and Fertilizer Studies with Celery ........ .........................................................
The Investigation of Vitamin C Content of Florida Fruits and Vegetables ............
Nutrient Salt Concentration in the Soil with Special Reference to the Trace
E lem ents ... ......................................................................................................................
Mineral Content of Vegetable Crops with Special Reference to Iron ........................
A Study of the So-Called "Quick Methods" for Determining Soil Fertility ................
The Florida Flower Thrips ... ...................................................................................
Root-Knot Investigations .... .. .. ... ...............................................................
Introduction and Propagation of Beneficial Insects ..................................................
The Larger Plant Bugs ........... ........................................... .........................
Control of Fruit and Nut Crop Insects-Insects Affecting Pecan Trees ........
The Onion Thrips (Thrips tabaci Lindin) ..................................
The Gladiolus Thrips (Taeniothrips gladioli M. & S.) ........................................
Biology and Control of Florida Aphids ..--- ..............................
The Pepper Weevil (Anthonomus eugenii Cano) ..................................................
A Study of the Pathologic Changes in Tissues Affected by Deficiency Diseases
or by Toxic Substances
An Investigation of Human Dietary Deficiencies in Selected Counties of Florida,
with Special Reference to Nutritional Anemia in Relation to Home Grown
F oods ........................................... ............................................................................
The Chemical Composition and Nutritive Value of Several Florida Honeys ..........
A Study of the Jelling Properties of Several Varieties of Florida Grapes ..........
Standardization of Home Canned Tomatoes and Tomato Juice ..............................
Variety Response of Pecans to Different Soil Types, Localities, etc. ...................
Cooperative Fertilizer Tests in Pecan Orchards .. .................................
Studies of Varieties of Pecans and Other Horticultural Nut-Bearing Species .......
Propagation, Planting and Fertilizing Tests with Tung-Oil Trees ......................
Testing of Native and Introduced Shrubs and Ornamentals and Methods for
Their Propagation ...................................................................................................









Department Number

HORTICULTURE 80
(Continued) 110
165
187
189
190
237
268
282
283

314
315
316

PLANT PATHOLOGY 126


Title


Page


Cover Crop Tests in Pecan Orchards ...................... ..... .................................... ...... 82
Phenological Studies on Truck Crops in Florida .............................................................. 84
Relation of Nitrogen Absorption and Storage to Growth and Reproduction in Pecans 85
Variety Tests of Minor Fruits and Ornamentals ........................................................... 86
Study on the Preservation of Citrus Juices and Pulps ....----......................... ............ 86
Cold Storage Studies on Citrus Fruits ........................................ ............................... 86
Maturity Studies of Citrus Fruits ................-..... ...................... ....................................... 87
A Study of the Relation of Soil Reaction to the Growth and Yield of Vegetable
C rops ........................................ .............................................................................. 88
Selection and Development of Varieties and Strains of Vegetables Adaptable to
Com m ercial Production in Florida .....---- ........................... ........................................ 88
Effects of Various Green Manure Crops on the Growth, Yield and Quality of
Certain Vegetable Crops ................... .................. .............. .........---...................... 90
Fumigation of Horticultural Products ........-............- ...................................................... 92
Fum igation of Nursery Stock ...... .......... ...... ................................................... ...---- 92
Fumigation of Seeds -----------.................... ....-........-.-- -- --....... ..- -......................... 92
Investigations Relative to Certain Diseases of Strawberries of Importance in
F lorida ......................................... ............... .......................................................... 93
Studies Relative to Disease Control of White (Irish) Potatoes .................................... 93
Investigation and Control of Brown Rot of Potatoes and Closely Related Crops
Caused by Bacterium solanacearum E. F. S. ...................... ..................... 94
A Comparative Study of Forms of Diplodia Resembling Diplodia frumenti ............ 95
Investigations of Diseases of Ferns and Ornamentals ......................................------.. 96
Investigation of and Control of Fusarium Wilt, a Fungous Disease of Water-
melons Caused by Fusarium niveum ........................................................................ 96
Investigation of and Control of Fungous Diseases of Watermelons ........................ 97
A Study of the So-Called "Rust" of Asparagus plumosus ........................................... 98
Control of Wilt of Tomatoes (Fusarium lycopersici Sacc.) in Florida .................... 98
Clitocybe Mushroom Root Rot of Citrus and Other Woody Plants in Florida ........ 99
Studies of Factors that Affect Decay of Citrus Fruits ................................................ 99
Investigations of a Bark Disease of Tahiti Lime Trees ................................................ 100
A Study of Sclerotium rolfsii Sacc. in Florida; Its Host Relations and Factors
Influencing Its Pathogenicity ...................................................................................... 101
A Study of Rose Diseases in Florida and Their Control .......................................... 101
Investigations of Fruit Rots of Grapes --...- ---....................... ..... ................................ 102
Collection and Preservation of Specimens of Florida Plants ........................................ 103
Virous Diseases of Pepper and Tomato ........................................................................... 104




Department Number


PLANT PATHOLOGY
(Continued)












SPECTROGRAPHIC
LABORATORY




FEDERAL-STATE
HORTICULTURAL
PROTECTION SERVICE

CITRUS STATION


269 Host Relations and Factors Influencing the Growth and Parasitism of Sclerotium
R olfsii Sacc. .................................................... ......................................
273 The Investigation of a Hitherto Unreported Disease of Beans in Florida Caused
by an Aerial Species of Rhizoctonia ........... ........... .....................
281 Treatment of Seeds and Soils for the Control of Seed-Borne and Soil-Borne
D diseases of P lants ........................ .... .. .................................... ..............
284 A Comparative Study of the Pathogenicity and Taxonomy of Species of Alter-
naria, Macrosporium, and Stemphylium .........................
313 Control of Diseases of Potatoes and Vegetable Crops Caused by Rhizoctonia ......
- Gummosis and Psorosis of Citrus Trees ...........................................
- Celery Spraying Experiments ......................... .... .....................................
- Pink Rot of Celery ...... .. ......................................................................................
- Downy Mildew Resistant Cantaloupes ... .......... .................................
- Downy Mildew Resistant Cucumber .......................................
- Two Fungous Diseases of Vegetables New in Florida ....................................

201 A Study of the Chemical Composition of the Ash of Florida Fruits and Vegetables
with Reference to the More Unusual Constituents ......................................
221 A Study of the Chemical Properties of the Glucosides of Citrus Fruits .........
256 The Development of Quantitative Spectrographic Methods for Agricultural Re-
search ............................
266 Spectrographic Studies of the Composition of Tissues and Corresponding Soils of
Normal and Physiologically Diseased Horticultural Crops .............................


No outlined projects; report of progress .................. ............................... .... 115

Melanose of Citrus and Its Control ..... ....... .......-......... ............................ 122
D ieback of Citrus .................................... ............ .................. .... ........................ ..... 122
Citrus Scab and Its Control ......................... ........................... .......... 126
Citrus Progeny and Bud Selection ....................................... 126
Propagation Experiments with Citrus Plants of Various Kinds ........................... 127
Testing of Introduced New Varieties and Hybrids of Citrus and Near Citrus ........ 127
Variety Testing and Breeding ........ ... ... ........ .................................................... 127
Citrus Soils Investigations ................ .................. ...... ............. ............ 127
Fundamental Physiology of Fruit Production ....................................................... 129
Investigations of Melanose and Stem-End Rots of Citrus Fruits .............................. 130
Control of Purple Scale and Whiteflies with Lime Sulfur ............................ 132


Title


Page









Department Number


CITRUS STATION
(Continued)


EVERGLADES
STATION
























NORTH FLORIDA
STATION


Title


238 Studies on the Effect of Zinc and Other Unusual Mineral Supplements on the
Growth of Horticultural Crops ....................................
266 Spectrographic Studies of the Composition of Tissues and Corresponding Soils of
Normal and Physiologically Diseased Horticultural Crops ............................


Page -
to


Fruit and Forest Tree Trials and Other Introductory Plantings ................................ 139
Soil Fertility Investigations Under Field and Greenhouse Conditions ....................... 140
Insect Pests and Their Control .......................................................................................... 141
Soils Investigations .............................................................................. ..................... 142
W after Control Investigations .................................................. ........................................... 143
Studies in Crop Rotation ...................................................................... 145
Studies Upon the Role of Special Elements in Plant Development Upon the Peat
and Muck Soils of the Everglades .............................-..................... .................... 146
Studies Upon the Prevalence and Control of the Sugarcane Moth Borer in South
Florida .......................................................... ................................................................ 147
Studies of the Prevalence and Control of Rodents Under Field and Village Con-
ditions ..................................................................... ....... ........ ..................................... 146
Cane Breeding Experiments ................................................................... ............... ........... 147
General Physiological Phases of Sugarcane Investigations ........................................ 147
Pasture Investigations on the Peat and Muck Soils of the Everglades ...........-........... 147
Agronomic Studies with Sugarcane ......................................-..........- 148
Forage Crops Investigations ......................................................................................... 149
Grain Crop Investigations ...................................................................................................... 150
Seed Storage Investigations ................................................................................................ 150
Fiber Crop Investigations .................................................................... .......................... 150
Cover Crop Investigations ................ ............ ......... ....... ..................... 151
Agronomic Studies Upon the Growth of Syrup and Forage Canes in Florida .......-. 151
The Seed and Soil-Borne Diseases of Vegetable Crops .................................................. 152
The Leaf Blights of Vegetable Crops ................................................................................ 154
Physiological Phases of Plant Nutrition ...........................------ ......-- ......----- .....-- ...... 156
Relation of Organic Composition of Agricultural Plants to the Progress of Vege-
tative Development and the Occurrence of Maturity .............................................. 157
Beef and Dual-Purpose Cattle Investigations ............................................................ 157
Nem atode Investigations ....... ............................................. ......... .................................. 158
Field and Laboratory Studies of Tobacco Diseases ........................................................ 160
Developing Strains of Cigar Wrapper Tobacco Resistant to Blackshank ................ 161
Comparisons of Various Grazing Crops with Dry Lot Feeding for Pork Production 161


t1o




Department Number
NORTH FLORIDA 160
STATION 191
(Continued)
219
241
257
260
261
305

SUB-TROPICAL 275
STATION 276
277
278
279
280
285
286
287
288
289
290
291
WEST CENTRAL -
FLORIDA STATION -


Title


Page


Fattening Fall Pigs for Spring Market .................................. ..............
Some Factors Affecting the Germination of Florida Shade Tobacco Seeds and
Early Growth of Seedlings ........................................ .......................................
Beef and Dual-Purpose Cattle Investigations .........................................
Efficiency of the Trench Silo for Preservation of Forage Crops as Measured by
Chemical Means and by Utilization of the Nutrients of Silage by Cattle ........
Columbia Sheep Performance Investigations .................................. ...............
Grain Crop Investigations ..............................................................
Forage Crop Investigations ................ ........... ....................................................
Comparison of the Economic Value of Various Grazing Crops for Fattening
Feeder Pigs ..............................................................................................
Citrus Culture Studies ...........................................................................
Avocado Culture Studies .. .... ...... ..............................................
Reforestation Studies .................. ......................................................... ...........................
Improvement of Tomatoes Through Selection of New Hybrids ....................................
Diseases of Minor Fruits and Ornamentals .................................... ..............
Studies of Minor Fruits and Ornamentals --.... --...................................-----
Potato Culture Investigations ..................... ....................
Tomato Culture Investigations ........ .......................................................................
Cover Crop Studies ... ................................ ........ ................................ ........
Varietal Tests of Carrots, Corn and Other Vegetable Crops .....................................
Control of Potato Diseases in Dade County ................. ............. ........ .......
A Study of Diseases of the Avocado and Mango and Development of Control
M measures .............................................................. ..........................................................
Control of Tomato Diseases by Spraying ......................................................................
Dual-Purpose Cattle ............................................. ...........................................................
Grasses and Forage Crops .......................... ...................................................................
The Use of Peanuts and Peanut Products in Rearing Turkeys ....................................
Confinement Versus Range Rearing of Chicks ................... ....................
Importance of Range Rotation in Poultry Production .............................................
Egg Production and Mortality of Pullets Reared Under Confinement Versus
Range Conditions ........................................
A Comparative Study of the Value of Milk Solids, Ground Peanut Kernels with
Hulls, Meatmeal and Fishmeal in Fattening Broilers and Fryers .....................
All-Night Lights Versus No Lights on Single Comb White Leghorn Hens ..............
Poultry Investigations-Miscellaneous ....... ................................ .............







Florida Agricultural Experiment Station


REPORT OF BUSINESS MANAGER

Receipts and expenditures of state funds for the fiscal year, covering
Main and Branch Stations, were as follows:


MAIN EXPERIMENT STATION
Receipts
Balance, 1935-36 ................... .....................................$ 6,516.80
Receipts, 1936-37 ................... ......-.................... ....... 154,003.70 *$160,520.50


Expenditures
Salaries ......---....--... .............-.........-.................$..... $ 75,046.52
Labor ....................-- ..........................-.................-......... 28,963.72
Stationery and office supplies ........................................ 1,132.79
Scientific supplies .................-...................................... 3,011.13
Feed .................................- .......................................... 8,105.16
Fertilizers ...........................- ......................................... 2,864.28
Sundry supplies ....................................................... ------3,063.97
Communication service ......................... ..... ............ 2,080.85
T ravel .................................................................. ............ 7,366.16
Transportation of things .---.-................-- --......--........- 1,191.41
Publications ......................................... ...................... 5,288.75
Heat, light, power ..--..................................................... 7,379.49
Contingent ......................................................................... 1,440.63
Furniture ......................-- ..---......... .......................... 1,621.31
Library ........................................................ ............... 2,014.89
Scientific equipment ...................................................... 860.85
Tools, machinery and appliances ................................... 5,236.88
Livestock ........................................................................... 371.05
Buildings ............................................................ ....... 3,480.66


CELERY INVESTIGATIONS


Receipts
Balance, 1935-36 ................................--- .......-- ......-- ......$ 3.83
Receipts, 1936-37 .............................---............-- ... 5,250.00


$160,520.50






$ 5,253.83


Expenditures
Salaries .............................................................................. $ 3,546.00
Labor ..............................-......-.........---- .--...-- ..--- ... .. 756.37
Scientific supplies ........................................... ... ....-- 56.27
Fertilizer .......-..---.-----...-..........-.....- .....--..----....--- 175.44
Sundry supplies ...-...--... -----------...--------....... 98.37
Communication service ..-.--......---.....-- ---------.......... 67.48
Travel .................................-- .............---- .........- -...... 168.10
Transportation of things ........................................ 23.68
Heat, light, power ...- --............-------- ----------....... 193.94
Contingent ....................................... ..... .----............. 10.00
Tools, machinery ..-----------------..........-- ----------...... 124.25
Buildings -------------..................... .-- ------.... 33.93 $ 5,253.83


*$19,646.80 had been deducted from appropriation for the Bankhead-Jones offset.







Annual Report, 1937


CITRUS DISEASE INVESTIGATIONS
Receipts
Balance, 1935-36 .......................................................... .$ 10.06
Receipts, 1936-37 ........................................................ 3,500.00 $ 3,510.06
Expenditures
Salaries .......................... ............................. .........$- 3,060.00
Scientific supplies ...............---. ---................---- 11.12
Communication ................... ...........................- 2.79
T ravel ........................................ ................. .................. 250.91
Scientific equipment ......................... ..................... 5.24
Buildings ............. ..................... 180.00 $ 3,510.06


FUMIGATION RESEARCH
Receipts
Balance, 1935-36 ..................................................$ 9.77
Receipts, 1936-37 ............. ........................... ........ 3,062.50 $ 3,072.27

Expenditures
Salaries .......................... ........... .................................. 2,700.00
Labor ............ ............................. .............................. 235.40
Stationery and office supplies ..................................... 4.08
Scientific supplies ..............-.............................. ... .48
Sundry supplies ........... .................................... ................ 35.42
Transportation ............................ ......... ........ 1.88
Heat, light, water and power ...................................... 16.03
Scientific equipment .................................................... 18.39
Tools, machinery and appliances ............................... 19.51
Buildings ........... ................................................................... 41.08 $ 3,072.27


GRAPE PEST INVESTIGATIONS
Receipts
Balance, 1935-36 ......................................................... $ 5.51
Receipts, 1936-37 .............................................................. 3,500.00 $ 3,505.51

Expenditures
Salaries .................................-............ $....... $ 2,520.00
Labor ....................................-............................ 374.60
Scientific supplies ........................................................ 17.71
Sundry supplies ...................................................... 44.98
Communication ................................................................ 57.09
Travel .... .............................................................................. 351.05
Transportation ................................................... 7.50
Heat, light, water and power ...................................... 106.30
Contingent ...................................................................... 4.50
Tools, machinery and appliances .................................. 21.78 $ 3,505.51






16 Florida Agricultural Experiment Station

PECAN INSECT INVESTIGATIONS
Receipts
Balance, 1935-36 ....................................... .................. 1,839.08
Receipts, 1936-37 ...................................... ......... 4,150.00 $ 5,989.08
Expenditures
Salaries ............................................................................$ 1,437.50
Labor .................................................................................. 575.74
Stationery and office supplies ...-................................... 12.33
Scientific supplies .......................................................... 272.69
Feed .................................................................................. 24.00
Fertilizer .........-..................................................... 262.27
Sundry supplies ..................................------.... 118.44
Communication ............................. ---..... ........ .38
Travel ....................................--....--...-.................... 135.65
Transportation ................................................................. 1.00
Heat, light, water and power ........................................ 14.65
Furniture ................................. ........... ....................... 474.41
Library ................................ ...... .................... 129.84
Scientific equipment ................................................ .. 32.23
Tools, machinery and appliances .................................. 1,367.41
Buildings ...............................................----- ........ ... 364.51
Balance .........................---........... .766.03 $ 5,989.08


POTATO DISEASE INVESTIGATIONS
Receipts
Balance, 1935-36 ...........----..----.... -............ 6.65
Receipts, 1936-37 ........................................................ 4,000.00 $ 4,006.65
Expenditures
Salaries ......................... .........-------.......$ 3,360.00
Labor ................. --....... ------....................... 127.00
Scientific supplies ...........................- ......-----.... 16.10
Fertilizer ............--....---- ..........-------- 39.84
Sundry supplies ...............--..... ----- ------....... 52.88
Communication .................----------------- ............ 64.25
Transportation ...................---- ....---- --.......... 14.67
Heat, light, water and power ..................................... 146.58
Contingent ............. .........---.....--.--..-....--- 34.41
Library ............................................................................. 2.00
Tools, machinery and appliances ...-........................ 48.92
Buildings ..........................----...... ----. ................. 100.00 $ 4,006.65


LABORATORY AT HASTINGS
Receipts
Balance, 1935-36 ...................................- .................-...$-- 5,250.00
Receipts, 1936-37 ..............................................----------.......... 5,250.00 $ 10,500.00
Expenditures
Labor ................................-------------------.....$ 1,574.13
Sundry supplies ..................................................... 73.14
Communication ...-...........------.. .....---.. ----.....-.. ... 15.10
Transportation ..................... ....------. ..... 87.57
Heat, light, power and water ............................ ........ 75.65
Contingent .......--...........--..-..-- .....-.-.-............ 84.05
Furniture ..................--- ..-- ..... ........... 1,098.97
Tools, machinery and appliances ................-............ 86.38
Buildings ..................................................-..... ..... 7,405.01 $ 10,500.00






Annual Report, 1937 17

STRAWBERRY INVESTIGATIONS
Receipts
Balance, 1935-36 ....... ...............................$ 65.43
Receipts, 1936-37 ........... ...................................... 6,300.00 $ 6,365.43
Expenditures
Salaries ..............................................................................$ 5,160.00
Labor .................................................................................. 601.00
Scientific supplies ....................................................... 86.95
Sundry supplies ...................... ................ ... 116.03
Communication ................................ 14.10
Travel ................. .......... ....................................... 197.78
Heat, light, water and power ........................................ 110.85
Furniture ....................................... 62.50
Scientific equipment ...................... ...................... 4.80
Tools, machinery and appliances .................................. 13.17
Buildings ............................................................ 8.25 $ 6,365.43

TOMATO DISEASE INVESTIGATIONS
Receipts
Balance, 1935-36 .....................................$ 111.50
Receipts, 1936-37 ............... .................................. 2,900.00 $ 3,011.50
Expenditures
Salaries ................................ ........................................ $ 2,160.00
Labor ......................................................-- -- -- 340.64
Scientific supplies ......................................................... 16.44
Feed ............................................ 46.20
Fertilizer ........................................................................... 11.61
Sundry supplies ................................................................ 59.57
Communication ............................ ...................... ... 65.91
Travel ............................................................................ .. 132.60
Heat, light, water and power ............................ ...... 129.97
Contingent ............................................. 7.50
Tools, machinery and appliances .................................. 41.06 $ 3,011.50

CITRUS EXPERIMENT STATION
Receipts
Balance, 1935-36 .................................. .....................$ 9,289.93
Receipts, 1936-37 ................. ................ .......... 46,451.00 $ 55,740.93
Expenditures
Salaries ........................................................................$ 19,580.00
Labor .................................................................................. 11,883.26
Stationery and office supplies ................................... 106.96
Scientific supplies ......................................................... 2,912.02
Feed .................................................................................... 632.00
Fertilizer ................................................ 1,291.65
Sundry supplies ................................................... 1,951.71
Communication .......................................... ......... ... 222.37
Travel ....................................... ...... ......... 2,412.50
Transportation .......................................................241.03
Heat, light, water and power ....................................... 1,025.87
Contingent .......................................................................... 133.55
Furniture ....................................... ....... 393.47
Library ......................................... .......... 280.27
Scientific equipment ........................................................... 950.42
Tools, machinery and appliances .................................. 2,578.27
Buildings .................................................. 9,145.58 $ 55,740.93







18 Florida Agricultural Experiment Station

EVERGLADES EXPERIMENT STATION
Receipts
Balance, 1935-36 .......................... ... -------. .....$ 622.96
Receipts, 1936-37 ................................. ...... 45,339.00 $ 45,961.96

Expenditures
Salaries ........- ........---------...........------ --- ---......--.. ...- $ 20,762.00
Labor ....................................... ......---------------..... 13,437.97
Stationery and office supplies ........--....... ------......... 162.74
Scientific supplies ...----------------.- ------------ 523.21
Feed .................. .......-.-. ... -- ----- 666.45
Fertilizer ..................-................-- .--- ---------------..... 6.80
Sundry supplies ...... ............ .............. 1,784.54
Communication ...----.....------- ----------- 269.64
Travel ............................................................................. .. 484.58
Transportation ..5...- ..................... ....- 59.03
Heat, light, water and power ........................................ 3,300.78
Contingent .........-..-- -----.. --.....-- .-------------. 259.51
Furniture ............------..........---------. 39.61
Library .................-- --.. ---------------......- 267.53
Scientific equipment ........-.......--.--.....------------- 187.69
Tools, machinery and appliances ............----.......... 2,350.81
Buildings .............................................. 1,399.07 $ 45,961.96

Everglades Continuing
Receipts, 1936-37 ............................. ......------------ $ 5,000.00 $ 5,000.00
Expenditures
Salaries ................--............... -- .............. .. $ 5,000.00 $ 5,000.00



NORTH FLORIDA EXPERIMENT STATION
Receipts
Balance, 1935-36 ................................-- --------..$ 77.18
Receipts, 1936-37 ......................----- ---------- --- 25,968.00 $ 26,045.18
Expenditures
Salaries .................. ...---------- -----------$..... 12,460.00
Labor ............................--------...----.. ---.. -- ........... 4,738.39
Stationery and office supplies .......--..---......-..... ------ 3.63
Scientific supplies .. .................................. 8.49
Feed ....................-------------- -------- 1,393.27
Fertilizer .............. .. .......... .... ..........---------- . -861.04
Sundry supplies .............................................................. 1,455.68
Communication ............-----....................-------- -------- 80.24
Travel .......................... ....... .. ............. ..............-. .. 386.80
Transportation ..----- --.----.---------------- 299.15
Heat, light, water and power ........................................ 538.64
Contingent .- ....--- ...---..-- ..---- --.--.------. 77.51
Furniture ....-............. --- ----- ----------- 51.89
Library ................ ............. ...... ....... ..... 15.20
Scientific equipment ...................-.....-------- 11.06
Tools, machinery and appliances .................................. 495.81
Livestock ................------ -........ ...... ...... 2,156.40
Buildings ..................................................................... 961.98 $ 26,045.18







Annual Report, 1937 19





SUB-TROPICAL EXPERIMENT STATION
Receipts
Balance, 1935-36 ........................................ ...... $ 11.93
Receipts, 1936-37 .......... ........................................ 10,579.00 $ 10,590.93

Expenditures
Salaries ......... --......-----..... ....................... -----$ 9,280.00
Labor ........................ .......-- ........................................ 377.75
Stationery and office supplies ........................................ 16.25
Scientific supplies ..... ...................................... 11.10
F eed ..................................................................... .............. 14.20
Fertilizer ......................................-................................ 190.20
Sundry supplies ............... .......................--------- 10.20
Com m unication ......................... ... ........... ...... 32.28
Travel ................ ....................... .................. --192.00
Transportation ........................-..........-- -...-..... ......... 31.91
Heat, light, water and power ...................................... 201.81
Contingent .......----.......- ......---------------- --4.50
Tools, machinery and appliances ......................-..---...... 24.20
Buildings ......... ............ ............................ 204.53 $ 10,590.93





WATERMELON INVESTIGATIONS
Receipts
Balance, 1935-36 .................................... .......... 94.57
Receipts, 1936-37 ...................................... ................ 7,000.00 $ 7,094.57
Expenditures
Salaries .......--.................. --.. ...............................------------- $ 5,500.00
Labor ................ -......................................................... 9 .997.42
Stationery and office supplies ....................................-... 10.37
Scientific supplies ..................- ........ .................. ... 86.26
F ertilizer ........................................................................... 173.85
Sundry supplies ............................................................... 41.05
Com munication ....................- .........................- ......... 33.74
Travel ....................................-----. ......... -....- -----........ 98.25
Transportation ......................-..................----------- .. ..----4.94
Heat, light, water and power .......----............................ 61.96
Contingent ........................... ... .......... 1.25
F furniture ........................................................................... 9.23
Library ................................................----................. ...... 8.50
Tools, machinery and appliances .................................. 67.75 $ 7,094.57







20 Florida Agricultural Experiment Station

SPECIAL-DAIRY INDUSTRY
Receipts
Balance, 1935-36 .................................... ...........$ 8,362.96
Receipts, 1936-37 ............................................... ....... 15,540.00 $ 23,902.96
Expenditures
Salaries .............................................................................. $ 6,100.00
Labor .................................................................................. 1,046.50
Scientific supplies ................................................... 492.11
Feed .......................................944.75
Sundry supplies ...................... .......... ..... ....... 40.51
Communication .................................................... .56
Travel ....................................................................... 282.71
Heat, light, water and power .................................. 13.44
Contingent ..................................... .......................... 14250
Furniture ........................................ ............ 669.16
Library ....... ............................... ...................... 29.40
Scientific equipment ........................................................ 2,792.03
Tools, machinery and appliances .................................. 10,525.32
Buildings ................................................................. 823.97 $ 23,902.96

SPECIAL-POULTRY INDUSTRY
Receipts
Balance, 1935-36 ................ .................... ....-...$ 3,583.52
Receipts, 1936-37 .......................................... ...... 12,500.00 $ 16,083.52
Expenditures
Salaries ...........$............--------... .--.... .................$ 5,100.00
Labor .............................................................. 4,246.75
Stationery and office supplies ........................................ 6.59
Scientific supplies .............................................. ... 222.89
Feed ...................................---. ..-----............. .... 1,024.89
Sundry supplies ....................................-.--.---.......... 189.35
Communication .......................................... ............ 14.84
Travel ..................................--------.....-----... ..---.----- 290.15
Transportation .............................. ...........-........ 21.62
Heat, light, water and power ...................................... 71.35
Furniture ...........--..................... .. .......... -. 296.57
Scientific equipment ............................................. 305.75
Tools, machinery and appliances .................................. 184.59
Livestock .................................................................... 97.25
Buildings ...........-............... ...--- . .....---- 4,010.93 $ 16,083.52

WEATHER REPORTS
Receipts
Balance, 1935-36 ... ...................................................$ 2,955.24
Receipts, 1936-37 ................................----...... 10,000.00 $ 12,955.24
Expenditures
Salaries .............. ..........---.......---- .......-- ------ $ 1,795.00
Labor ...................-----...- .....--.--..--------........... ..... 169.40
Stationery and office supplies .................................... 68.34
Sundry supplies ....................................------- ................. 64.19
Communication .......................................... 2,078.56
Travel ..............................--- ...------ .. ... 2,672.95
Contingent ................................................................. .. 29.56
Furniture ......................................... 576.96
Scientific equipment ...................................... .... 5,128.86
Buildings ........ ....... ............-.................................. 371.42 $ 12,955.24







Annual Report, 1987 21




BANKHEAD-JONES, FEDERAL
Receipts, 1936-37 ..............................................................-----................... 15,400.82
Expenditures
Salaries .....-.....................----. ... ----$ 1,362.90
Labor .................................. ............ 5,362.99
Stationery and office supplies .........................-.....--2.10
Scientific supplies ............ ..................... 48.50
Fertilizers ............................................... .. ......... 80.85
Sundry supplies ...........................................-- 388.96
Communication service .............................................-- 1.85
Travel .................................................................................. 198.20
Transportation of things ...................................-- 2.91
Heat, light, power ..................................................... 233.40
Contingent ..............................................----- ..... 124.50
Furniture ......................................................................... 133.73
Scientific equipment ....................................................... 19.23
Tools, machinery, appliances ........................................ 870.84
Livestock ......................... --. .............. ... 507.00
Buildings and land ......................... .... ......... 6,062.86 $ 15,400.82



BANKHEAD-JONES OFFSET, STATE*
Receipts from Main Station* ........................ .................................$ 19,646.80
Expenditures
Salaries ....................................---...... $ 7,920.00
Labor ........................................ 8,801.70
Stationery and office supplies .....................................--- 43.55
Scientific supplies ...................................----...--- ..-- ---. 121.52
Feed ............................. ...---............ ----------....... 44.50
Fertilizer ... ..................................................................... 274.08
Sundry supplies--------------------------------632.24
Sundry supplies ..........................................--......................---- 632.24
Communication service .........................-------- 50.98
Travel ..............................-......----.. 435.77
Transportation of things ..............................-- -...- 4.30
Heat, light, power ................................ ----... 159.05
Library .................................. ..................--- .--- 38.06
Tools, machinery, appliances .............................--.....---. 153.93
Buildings and lands ........................................................ 599.33 $ 19,646.80

FEDERAL HATCH AND ADAMS FUNDS
Receipts
Hatch fund ........................ ...................................... 15,000.00
Adams fund .................................................. ......... 15,000.00 $ 30,000.00
Expenditures
Salaries ....................................... ..-----------.........................................$ 30,000.00
*See Main Station Statement.







Florida Agricultural Experiment Station


EDITORIAL AND MAILING DEPARTMENT

Information work in the Experiment Station reflects most of the current
activities and makes available facts and knowledge gained by research in
the past. Through it endeavor is constantly made to carry to farmers and
to other interested groups correctly balanced, readily comprehensible,
adequate, and usable knowledge. Research findings must be made avail-
able or they have failed in their ultimate purpose. New information is
constantly becoming available and already established facts are presented
to the public through bulletins, stories and articles in newspapers, farm
papers and technical journals, radio talks, folders, and other methods.
Less than one-half of the time of the three editors is devoted to work
for the Experiment Station, the other part going to Agricultural Extension
Service activities. The mailing room clerks, however, devote about half
of their time to distributing Station bulletins and materials, and sent out
close to 100,000 copies of these bulletins this year.

TWELVE NEW BULLETINS PRINTED
Twelve new bulletins were printed during the fiscal year-an average
of one a month. In each case the manuscript was prepared by the author,
approved by the head of his department, checked and approved by the
Bulletin Committee and the director. Copy was edited for printing and
proof was read in the Editorial Department.
Five of the bulletins were technical and seven popular in nature. Due
to limited finances, all 12 new bulletins were held to small editions of
between 5,000 and 10,000 copies, with a total of 80,500 copies being printed.
The bulletins varied in size from 12 to 76 pages, and totalled 448 pages
of printed matter.
Following is a list of bulletins issued during the year, with page sizes
and number of copies of each:
Bul. Title Pages Edition
299 Brown Rot of White Potatoes and Its Control ..........-....... 44 7,500
300 A Manganese Deficiency Affecting Beans .....................-..-- 24 6,000
301 Effects of Summer Cover Crops on Crop Yields and on


the Soil, I and II ................................................................
Field Characteristics and Partial Chemical Analyses of
the Humus Layer of Longleaf Pine Forest Soils ..........
Cold Storage Studies with Florida Citrus Fruits, I ...........
Cold Storage Studies with Florida Citrus Fruits, II .......
The Etiology of Fowl Paralysis, Leukemia and Allied
Conditions in Animals, V and VI .....................................
The Etiology of Fowl Paralysis, Leukemia and Allied
Conditions in Animals, VII and VIII ............................
Cracked Stem of Celery Caused by a Boron Deficiency
in the Soil .......................................................................
Experiments for the Control of Phoma Rot of Tomatoes
Development of the Root-Knot Nematode on Beans as
Affected by Soil Temperature .....................................
The Pepper W eevil ........................................... ..............


6,000

5,000
10,000
10,000

5,000

5,000

6,000
8,000

6,000
6,000


SUMMARY OF BULLETINS
299. Brown Rot of White Potatoes and Its Control. (A. H. Eddins,
pp. 44, figs. 8.) Experiments in which soils infested with Bacterium
solanacearum, the organism causing brown rot, were treated with single







Annual Report, 1937


applications of inoculated sulfur after the potatoes were removed and then
given an application of dolomitic limestone before new potatoes were planted
on them showed that brown rot could be controlled in this manner. Tech-
nical.
300. A Manganese Deficiency Affecting Beans. (G. R. Townsend and
H. H. Wedgworth, pp. 24, figs. 6.) Yellowing, a nutritional disorder of
beans growing on weakly acid to alkaline peat soils, is attributable to
lack of manganese, and can be corrected by light applications of manganese
sulfate or sulfur, or both. The sulfur tends to acidify the soil and make
manganese more available.
301. Effects of Summer Cover Crops on Crop Yields and on the Soil.
(W. E. Stokes, R. M. Barnette and J. B. Hester, pp. 24, figs. 4.) Part I
shows that corn and sweet potatoes rotated with various summer cover crops
returned highest yields after Crotalaria striata. Both velvet beans and
cowpeas showed up well in this experiment. In part II it is shown that
leguminous summer cover crops plowed into the soil increase the amounts
of nitrates in the soil from the first of February to the middle of June,
and that accumulation of nitrates in Norfolk sand depends primarily on
the amount of rainfall.
302. Field Characteristics and Partial Chemical Analyses of the Humus
Layer of Longleaf Pine Forest Soils. (Frank Heyward and R. M. Barnette,
pp. 28, figs. 8.) Where longleaf pine forests are subjected to recurrent
fires, a type of humus layer more typical of grassland than of forest
occurs. A total forest floor of from 20,000 to 55,000 pounds per acre may
accumulate in forests protected from fire for 10 years or more, after which
no further increase in total quantity occurs. Technical.
303. Cold Storage Studies of Florida Citrus Fruits, I. (Arthur L. Stahl
and A. F. Camp, pp. 68, figs. 13.) Reports effect of temperature and
maturity on changes in keeping quality of oranges and grapefruit in cold
storage. With pineapple oranges there were decreases in weight, volume,
and percent of juice, only slight changes in other constituents. Valencias
decreased in weight, specific gravity, percent juice and acid, and increased
in total sugars and pH values. Loss in weight of all varieties (oranges
and grapefruit) was less at lower temperatures. Pitting in grapefruit
was more severe at lower temperatures.
304. Cold Storage Studies of Florida Citrus Fruits, II. (Arthur L.
Stahl and Willard M. Fifield, pp. 80, figs. 23.) Describes effect of various
wrappers and temperatures on the preservation of citrus fruits in storage.
Moistureproof wrappers were superior in reducing loss in weight and
preserving general appearance of oranges and grapefruit. Stem-end rot
was the most prevalent decay. Temperature, and not wrappers, was the
controlling factor in pitting of grapefruit.
305. The Etiology of Fowl Paralysis, Leukemia and Allied Conditions
in Animals, V and VI. (M. W. Emmel, pp. 68, figs. 4.) Section V reports
on the oral exposure of chickens infected with various species of Eimeria
to Salmonella aertrycke, while section VI concerns experiments in which
chickens infected with Ascaridia, Taenia, and Capillaria were exposed to
the same organism. It was found in both cases that many of the exposed
birds developed one or more pathologic manifestations of disease. Tech-
nical.
306. The Etiology of Fowl Paralysis, Leukemia and Allied Conditions
in Animals, VII and VIII. (M. W. Emmel, pp. 44, figs. 8.) Hemocyto-
blastosis is a fundamental process in the development of many pathologic
manifestations resulting from infection by many species of the genus







Florida Agricultural Experiment Station


Salmonella. Hemocytoblastosis was more pronounced in birds affected
with "light", anemia and unthriftiness and less pronounced in birds affected
with lymphomatosis. Technical.
307. Cracked Stem of Celery. (E. R. Purvis and R. W. Ruprecht,
pp. 16, figs. 3.) Cracked stem is due to a boron deficiency in the soil,
and is corrected by the application of commercial borax to the soil at the
rate of 10 pounds per acre.
308. Experiments for the Control of Phoma Rot of Tomatoes. (W. B.
Tisdale and Stacy O. Hawkins, pp. 28, figs. 0.) Phoma spot of winter
tomatoes in the Homestead area is most destructive during seasons of
moderate temperatures and high humidities. Spraying with bordeaux and
washing the fruit with certain washes reduced the percentage of rot.
309. Development of the Root-Knot Nematode on Beans as Affected
by Soil Temperature. (G. R. Townsend, pp. 16, figs. 0.) Development of
the nematode, Heterodera marioni, would not be expected at temperatures
below 14.75 C., although some may occur at temperatures as low as
12 C. The number of generations per year increases with temperature,
and may reach 10 or 12 in southern Florida. Technical.
310. The Pepper Weevil. (C. C. Goff and J. W. Wilson, pp. 12,
figs. 3.) This weevil, first sent to the Experiment Station for identifica-
tion in 1935, causes considerable damage to peppers in infested areas.
Dusting combined with careful picking of infested fruits gives control
of the pest.
PRESS BULLETINS
Nine new press bulletins were issued during the year, and an equal
number of old ones was reprinted. Each press bulletin, usually two pages
in length, contained succinct information about some specific subject. Press
bulletins are used largely in answering inquiries, and to a certain extent
in supplying information for press releases. Following is a list of press
bulletins printed during the fiscal year.

No. Title Author
498 Control of Downy Mildew (Blue Mold) of Tobacco in Florida
-Randall R. Kincaid
499 Some Reasons Why Roses Fail .................................. William B. Shippy
500 Sea Island Cotton .............................. ..............................W E. Stokes
501 Collecting Deer Tongue Leaves ................................ J. Francis Cooper
502 Papaya Culture ............................................. ........ ................. H. S. W olfe
503 Wintering Beef Cattle in Florida .................................... W. W. Henley
504 Flordo Spray ... ............................... .......................... W illiam B. Shippy
Bulletin List (printed twice)
420 Disinfectant Pastes and Washes for the Treatment of Bark
Diseases of Citrus Trees (reprint) ...................... Arthur S. Rhoads
430 The San Jose Scale (reprint) .............................................. J. R. Watson
435 Powdery Mildew of Crape Myrtle (reprint) .................. Erdman West
436 Orange Rust of Blackberries (reprint) .......................... Erdman West
451 Crotalaria (reprint) .............................. W. E. Stokes and W. A. Leukel
458 Some Poisonous Plants in Florida (reprint) .................. Erdman West
462 Papaya Leaf Spot (reprint) .............................................. Erdman West
474 Blackberries and Dewberries (reprint) ............................ Harold Mowry
476 Infectious Laryngotracheitis (Infectious Bronchitis) in
Poultry (reprint) ........................ ...................... M. W. Emmel







Annual Report, 1937


NEWS STORIES, FARM PAPER ARTICLES
Newspapers and farm journals constitute an excellent medium for
reaching the public with information. The papers are kept on hand for
a short or long period and can be referred to more than once, or they
can be clipped as desired. Their editors are anxious to carry information
concerning new discoveries in agricultural research, or authentic informa-
tion concerning the best methods of carrying on farm and grove activities.
They give hearty reception to Experiment Station articles.
Several dozen articles prepared by staff workers, primarily for radio
delivery, were revised and forwarded to farm publications in Florida,
where they were printed during the fiscal year. Most of these were sent
on request from the publications concerned, and they covered a wide field
of popular information.
Articles prepared by the editors themselves and published in two Florida
farm publications during the year numbered nine, and took 296 column
inches of space. One Southern farm magazine used seven such articles,
measuring 52 inches.
The weekly clipsheet of the State Agricultural Extension Service, sent
to all Florida weeklies and some dailies for reprint, contained numerous
releases about the Experiment Station and its workers. Three dailies
carried weekly columns of questions and answers on farming subjects,
and practically all of this information came from the Station. Special
releases were handled by the Associated Press from time to time for its
member papers in Florida and occasionally outside the state.

RADIO RELEASES
Experiment Station staff members played an important part in the
Florida Farm Hour radio programs at noon each week day over WRUF,
under the direction of the Extension Service. They made a total of 165
talks on this program during the year, or an average of one every other
day. Every department at the main station and many of the branch
stations and field laboratories were represented.
Twenty-seven of these talks were copied and forwarded as farm flashes
to other radio stations throughout the state.
In addition to talks made during the Florida Farm Hour, six Station
workers spoke over WRUF at various other times, particularly during
broadcasts of the Little International Livestock Show and the State
Horticultural Society.
The director of the Experiment Station spoke over a National Farm
and Home Hour hook-up of the National Broadcasting Company on Sep-
tember 16, 1936, when he emphasized the results of research work and
its effects on the agriculture of this state. Assistance in organizing this
program was rendered by this office.

MISCELLANEOUS
Two additional "Little Stories of Florida Agriculture" were printed
and distributed during the fiscal year, bringing the series to a conclusion
with No. 24, August 1936. These were 4-page folders which could be
included in envelopes being mailed during the month, and carried stories
of outstanding achievements by research workers.
This series attracted widespread attention and interest, and brought
numerous requests for complete sets of the "little stories". Five thousand
copies of each issue were printed.







Florida Agricultural Experiment Station


Staff members appeared frequently before scientific societies, associa-
tions, civic clubs, and other organizations and presented facts about the
institution and its work.

SCIENTIFIC AND POPULAR ARTICLES IN JOURNALS
A large number of articles concerning research at the Florida Station
were printed in scientific and technical journals throughout the country.
These were prepared by investigators on the staff, and only occasionally
were they edited in this office before being submitted direct to the journals.
Many popular articles by staff members, other than editors, were
printed in farm journals during the year also. Some of these were sent
by the editors and others were sent direct.
Following is a list of scientific, technical and popular articles written
by Florida Station staff members and printed during the fiscal year:
Absorption Spectrophotometry. Lewis H. Rogers. Proc. Fla. Acad.
Sci., 1937.
A Comparison of Rough Lemon and Sour Orange as Citrus Rootstocks
on Light Sandy Soils. A. F. Camp and J. H. Jefferies. Cit. Industry,
18:2. Feb. 1937.
A Comparison of Seedless and Seedy Grapefruit Varieties. A. F. Camp
and J. H. Jefferies. Cit. Industry, 18:1. Jan. 1937.
A Field Trip to the Devil's Millhopper. Lillian E. Arnold. Jour. Elisha
Mitchell Sci. Soc., 52:1. July 1936.
An Epiphytotic of Alga Spot in Southern Florida. Geo. D. Ruehle.
Plant Dis. Reporter, 20:14. Aug. 1936.
Applying to Ice Cream the Minnesota Babcock Butterfat Test. L. M.
Thurston and W. C. Brown. Ice Cream Field, 30:4. 1937.
A Preliminary List of the Tabanidae (Diptera) of Florida. G. B. Fair-
child. Florida Entomologist, 19:4 and 20:1. 1937.
A Southeastern Poultry Council-When and Why. N. R. Mehrhof.
Proc. Sou. Agr. Workers. Feb. 1937.
Clean-Up Measures Against Rust Mites. J. R. Watson. Fico News,
July 1936.
Coccidiosis Like Music "Goes Round and Round". M. W. Emmel. Fla.
Poultryman. Mar. 1937.
Composition of Citrus Fruit Juices. J. A. Roberts and L. W. Gaddum.
Jour. Ind. and Eng. Chem., 29:574. May 1937.
Controlling Grasshoppers in Orange Groves. J. R. Watson. Citrus
Industry. Nov. 1936.
Control Measures for Mealy Bugs on Citrus. J. R. Watson. Citrus
Industry. July 1936.
Control Measures for Rust Mites. J. R. Watson. Fico News. June
1937.
Does Annual Fertilization in a Pecan Orchard Pay? G. H. Blackmon.
Proc. S. E. Pecan Grs. Assn. 1937.
Early and Late Injury of Rust Mites on Oranges. W. L. Thompson.
Proc. Fla. State Hort. Soc. 1937.
Effect of Rainfall and Substrata Upon Composition and Reaction of
Soil Waters of Everglades Peat Land. J. R. Neller. Proc. Intnatl. Soc.
Soil Sci. Abst., 12:31-32. 1937.
Fall Clean-Up Measures Against Scale Insects and Whitefly. J. R.
Watson. Citrus Industry. Oct. 1936.







Annual Report, 1937


Fertilizer Experiments with Pecans. G. H. Blackmon. Proc. Natl.
Pecan Assn. 1936.
Fowl Paralysis. M: W. Emmel. Successful Farming, 34:66. 1936.
Grape Varieties for Florida. R. D. Dickey. Proc. Sou. Agr. Workers,
1937.
Grasses in Florida. W. E. Stokes. Florida Cattleman, 1:2. Nov. 1936.
Hemorrhagic Septicemia Investigations. The Significance of Pasturella
boviseptica Encountered in the Blood of Some Florida Cattle. D. A.
Sanders. Journ. Amer. Vet. Med. Assoc., N. S., 43:6. June 1937.
Infra-red Absorption Spectrum of Vitamin C. Dudley Williams and
L. H. Rogers. Proc. Am. Chem. Soc. 1937.
Insect Pest Conditions Forecast. J. R. Watson. Fico News. May 1937.
Insect Pests of Cover Crops. J. R. Watson. Citrus Industry. Oct. 1936.
La Cria y Explotacion de Ganado Lechero en la Florida Revista Agri-
cola. "J" Arnold, R. B. Becker and Bruce McKinley. Reprinted in La
Hacienda (Nicaragua). Aug. 1936.
Methods of Controlling Frenching. Walter Reuther. Fico News, 4:11.
Feb. 1937.
Microdetermination of Zinc. Comparison of Spectrographic and Chem-
ical Methods. L. H. Rogers and 0. E. Gall. Ind. and Eng. Chem. (Anal.
Ed.), 9:42. Jan. 1937.
Observations on Canine Babesiasis piroplasmosiss). D. A. Sanders.
Journ. Amer. Vet. Med. Assoc., N. S., 42:2. Aug. 1936.
Observations on Psorosis of Citrus Trees in Florida. A. S. Rhoads.
Proc. Fla. State Hort. Soc. 1937.
Oxidation in Relation to Off-flavors in Milk and Certain Milk Products.
L. M. Thurston. Proc. Am. Chem. Soc. 193'1.
Oxidized Flavor in Milk. II. The Effects of Homogenization, Agitation
and Freezing of Milk on Its Subsequent Susceptibility to Oxidized Flavor
Development. L. M. Thurston. Journ. Dairy Sci., 19:671. 1936.
Oxidized Flavor in Milk. III. The Time of Copper Contamination Dur-
ing Production and Processing, and Aeration Versus no Aeration as Related
to Oxidized Flavor Development. L. M. Thurston. Journ. Dairy Sci.,
19:753. 1936.
Oxidized Flavor in Milk. IV. Studies of the Relation of the Feed of
the Cow to Oxidized Flavor. L. M. Thurston and W. C. Brown. Journ.
Dairy Sci., 20:133. 1937.
Oxidized Flavor in Milk. L. M. Thurston. Proc. Fla. Dairy Products
Assn. April 1937.
Oxidized Flavor in Milk. L. M. Thurston. Proc. Ala. Dairy Products
Assn. Jan. 1937.
Pastures and Their Grazing Capacities. W. E. Stokes. Florida Cattle-
man, 1:3. Dec. 1936.
Pecan Variety Response to Fertilizer. G. H. Blackmon. Proc. Assoc.
South. Agr. Workers. 1937.
Pest Control in Florida Citrus Groves. A. F. Camp, W. L. Thompson
and W. A. Kuntz. Amer. Fruit Grower, 57:2. Feb. 1937.
Plant Bugs in Citrus Groves. J. R. Watson. Fico News. Sept. 1936.
Potato Diseases in Dade County, Florida, During 1936-37 Season. G. D.
Ruehle. Plant Disease Reporter, 21:7. Apr. 1937.
Practical Aspects of Fowl Paralysis and Leukemia Problems in Chick-
ens. M. W. Emmel. Proc. Assn. Sou. Agr. Workers. 1937.







28 Florida Agricultural Experiment Station

Practical Proving of Dairy Sires. R. B. Becker and P. T. Dix Arnold.
Proc. Assn. Sou. Agr. Workers. 1937.
Pullorum Disease in Captive Quail. M. W. Emmel. Journ. Amer. Vet.
Med. Assoc., 89:716. 1936.
Recent Advances in the Field of Vitamin Chemistry. L. L. Rusoff.
Proc. Fla. Acad. Sci. 1936.
Sampling Soil for the pH Determination. A. H. Eddins and Wi. H.
Scoville. Soil Sci., 43:3. March 1937.
Sclerotinia Rot of Irish Potatoes. A. H. Eddins. Phytopath., 27:1.
Jan. 1937.
Some Changes in the Soil Fauna Associated with Forest Fires in the
Longleaf Pine Region. Frank Heyward and A. N. Tissot. Ecology, 17:4.
Oct. 1936.
Some New Pecan Products. G. H. Blackmon. Proc. S. E. Pecan Grs.
Assn. 1937.
Some Soil Qualities of Practical Interest. Michael Peech. Proc. Fla.
State Hort. Soc. 1937.
Summer Oil Sprays for Citrus Fruits. W. L. Thompson. Cit. Industry,
17:7. July 1936.
Supplements in Dormant Bordeaux Sprays for Insect Control on Citrus.
W. L. Thompson. Cit. Industry, 18:1. Jan. 1937.
Swine Production in the Southeast. W. G. Kirk. Jour. Am. Soc. of
Animal Prod. Nov. 1936.
The Dam as a Transmitter. P. T. Dix Arnold and R. B. Becker. Proc.
Asso. Sou. Agr. Workers. 1937.
The Importance of Endotoxin of Salmonella aertrycke in the Develop-
ment of Fowl Paralysis. M. W. Emmel. Jour. Amer. Vet. Med. Assn.,
90:749. 1937.
The Inheritance of Screw Tail in Cattle. B. Knapp, Jr., M. W. Emmel
and W. F. Ward. Journ. Heredity, 27:269. 1936.
The Pathology of Crotalaria spectabilis Roth. Poisoning in Cattle.
D. A. Sanders, A. L. Shealy and M. W. Emmel. Jour. Amer. Vet. Med.
Assoc., N. S., 42:2. Aug. 1936.
The Pathology of Crotalaria spectabilis Roth. Seed Poisoning in the
Domestic Fowl. M. W. Emmel. Jour. Amer. Vet. Med. Assoc., 90:627.
1937.
The Value of Legumes in Maintaining the Fertility of Orchard Soils.
G. H. Blackmon. Proc. Sou. Nsymen's Assoc. 1936.
The Value of Summer Cover Crops. R. M. Barnette. Cit. Industry,
17:7. July 1936.
Time to Plant Pastures. W. E. Stokes. Fla. Cattleman, 1:9. June
1937.
Toxicity of Mercury Vapor to Germinating Tobacco Seeds. R. R.
Kincaid. Plant Physio., 11:654. 1936.
Watermelon Aphids Abundant. A. N. Tissot. Fla. Grower. May 1937.
Wettable Sulfur as a Supplement for Lime-Sulfur, Copper and Zinc
Sprays. W. L. Thompson. Cit. Industry, 18:3. March 1937.
Winter Pastures. W. E. Stokes. Florida Cattleman, 1:1. Oct. 1936.
Warm Air Roof Makes Grove Heating Possible. Eckley S. Ellison.
Fla. Col. Farmer, 5:1. Dec. 1936.







Annual Report, 1937


LIBRARY

Library activities for the fiscal year are set forth in the following
tabulation:

Volumes sent to the bindery ..................................... 360
Volumes received by purchase, gift and exchange .... 208
Total number books accessioned during year ............ 568
Total number bound volumes in library ................. 13,603
Pamphlets, continuations, etc., received .................... 12,720
Number pieces lent to branch stations ....................... 431
Books borrowed from other libraries ........................ 83
Catalog cards prepared, typed and filed .................. 4,961

The growing importance of agriculture and agricultural research was
definitely shown by the receipt of 12,720 pieces of agricultural literature.
This is the largest amount of material ever received in any year, and
exceeded that of the previous one by 3,550 publications. Governmental
interest in agriculture and related sciences, in both this and foreign coun-
tries, is largely responsible for the greatly increased number of publications.
Circulation of periodicals to staff members located at branch stations
and field laboratories was as successful as in previous years. Eighty-
three books were borrowed from other libraries. This courtesy on the
part of libraries, including those of the United States Department of Agri-
culture, War Department, Surgeon General, Library of Congress, John
Crerar of Chicago, agricultural experiment stations and many others,
has made it possible for the Librarian to secure the major amount of
material needed by the scientific staff.
The Library continued its policy of the previous year of remaining
open during the evening from October through May. By actual count 197
students made constant use of it during those hours.
With the amount of assistance available it is now possible to catalog
only the bulletin series of the Agricultural Experiment Stations and Agri-
cultural Extension Services of the various states. There were 1,219 of
these received, all of which have been catalogued. Library of Congress
supplies catalog cards for the publications issued by the United States
Department of Agriculture. For the other publications received it is
necessary to rely on Experiment Station Index, Agricultural Index, Read-
ers' Guide, Plant Literature and other similar reference tools.
The Librarian gratefully acknowledges the gift from President Tigert
of a copy of David Livingston Crawford's "Hawaii's Crop Parade" and
from Dr. M. W. Emmel and Dr. D. A. Sanders of the Journal of American
Veterinary Medical Association, volumes 54-89 (n. s. v. 7-42), 1918-1936.







Florida Agricultural Experiment Station


AGRICULTURAL ECONOMICS

Work for the year was concentrated on four projects, two of which
deal primarily with farm and grove management and two with marketing
problems.

AGRICULTURAL SURVEY OF SOME 500 FARMS IN THE
GENERAL FARMING REGION OF NORTHWEST FLORIDA
Purnell Project 73 C. V. Noble, Bruce McKinley
and A. H. Spurlock
Field work was completed for the repeat economic survey of a repre-
sentative sample of the farms covered in the 1926 survey. The data
forming the basis for the analysis now in progress are being obtained
from complete farm survey records of 499 Jackson County farms for the
year 1925, 110 farms for 1928, 42 farms for 1934, and 140 farms for 1935.
Outstanding measures of success are brought out for each year of the
survey by comparing with the entire group the quarter of the farms pro-
ducing the highest labor incomes to their operators. This comparison is
shown in Table 1.
It will be noted that for each year the farms with the highest labor
incomes had larger acreages of cropland, usually obtained better crop
yields, and received better prices for crops sold than the average farm.

FARMERS' COOPERATIVE ASSOCIATIONS IN FLORIDA
Purnell Project 154 H. G. Hamilton and C. V. Noble
To bring Florida bulletin 245 up to date, the names of all farmers'
cooperative associations that had received charters from the Secretary of
State since the publication of the above bulletin were obtained, and a
check-up was made by questionnaire, correspondence and visitation to de-
termine as nearly as possible the number of farmers' cooperatives in
operation. The attempt also was made to locate unincorporated organiza-
tions as well as those holding a state charter. This check-up, which was
completed through March 13, 1937, revealed a total of 554 farmers' co-
operatives of all types. Of this number, 166 were reported as active and
the remaining 388 as either temporarily inactive or permanently out of
business.
On June 1, 1937, field work was started in unofficial cooperation with
the Farm Credit Administration of Columbia, S. C., to make a thorough
study of all active cooperatives in the State. The results from this study
should bring the work reported in Florida bulletin 263 up to date. This
field work is in progress at present.

COST OF PRODUCTION AND GROVE ORGANIZATION STUDIES
OF FLORIDA CITRUS
Purnell Project 186 Zach Savage and C. V. Noble
The work on this project was started in 1932. Summary sheets have
been prepared and returned to each cooperator at the close of each fiscal
year. The summary reports for the fiscal year 1935-36 are for the fourth
completed year of the project and show comparisons of the various items
for four years. Comparable figures from the individual cooperator's ac-
counts are included in his own report in the column headed "Your Grove".
A copy of the summary sheet for mid-season oranges 12 to 14 years of
age is here shown as Table 2.








TABLE 1.-SUMMARY OF SURVEYS OF FARMS IN JACKSON COUNTY, FLORIDA, FOR THE YEARS 1925, 1928, 1934 AND 1935
(PRELIMINARY).
Year 1925 1928 1934 1935
Average Average Average Average
All Best All Best All Best All Best
Farms Fourth Farms Fourth Farms Fourth Farms Fourth

Number of farms ................... ............ 499 125 110 28 42 10 140 35
Size of business:
Acres operated .. .............................................. 132 144 154 125 192 339 155 206
Acres cropland ..................................................... 71 91 74 78 93 151 82 108
Total capital ................................... ..................... $5,818 $6,779 $6,948 $5,894 $5,779 $7,135 $4,407 $5,163
Production: o
Crop index .............. .................................... 100 119 100 117 100 99 100 105
Price:
Price index of crops ........................................ 100 105 100 108 100 107 100 105 QQ
Income:
Farm receipts ....................................................... $1,592 $2,931 $1,313 $1,710 $1,514 $2,996 $1,154 $1,920
Farm expenses .. ..... .................................... 1,087 1,534 1,164 1,090 980 1,616 900 1,204
Farm income ......................................................... ... 505 1,397 149 620 534 1,380 254 716
Labor income ........................................................ 98 923 -337 208 129 881 -54 355
Family income ............. .................................. 686 1,611 277 780 619 1,483 349 782
Percent return on capital ................................ 4.3 16.1 -1.3 5.8 4.3 12.0 -.1 6.8








Florida Agricultural Experiment Station


TABLE 2.-COSTS AND RETURNS FOR MID-SEASON ORANGES, 12 TO 14 YEARS
OF AGE*.
Average Average Average Average
all I all all all Your
groves I groves groves groves grove

Season .............. .......... ................................. 1932-88 1988-84 1934-35 1936-86
Number of accounts ................................................. 4 9 12 11
Age of grove (years) ......... ....... 12to14 12to14 12to14 12to14
Acres per grove .................................................... 21.67 11.02 9.81 8.08
Trees per acre .............................................. 61 65 66 74
Grove value per acre ................................................ $639.95 $651.01 617.86 $663.91
Yield in boxes per acre ..................................... 188 106 128 113
Yield in boxes per tree ..................................... 2.24 1.63 1.95 1.52

Costs per acre:
Labor ........................... ........ $12.86 $10.08 $10.51 $ 8.00
Supervision ... .............................. ................ 10.13 10.82 6.39 2.29
Power and equipment ............................. .. 6.19 5.84 4.82 3.87
Labor, power and equipment not separated ... .15 1.06' 1.882 3.27'
Fertilizer .............................. ................ ..... 17.24 14.48 20.44 20.68
Soil amendments .......................................... .70 .81 1.48 1.68
Spray and dust .... .. ........................... 2.08 2.80 2.19 2.51
Irrigation and drainage ................................. 2.26 1.70 1.66 2.20
Taxes ................................................ ................. 4.79 4.07 6.00 4.54
Interest on grove at 7% ................................. 44.80 45.57 43.25 46.47
All other costs ................................................... 2.02 2.41 2.56 .74
Total costs per acre .. .............................. 102.67 98.14 100.68 96.15
Returns per acre ...................... ........... 127.90 54.68 107.81 151.79
Profit per acre (- denotes loss) .............................. 25.23 -48.46 6.68 55.64
Costs per box ... ................................................ .746 .926 .785 .849
Returns per box .... ................................ .929 .516 .87 1.341
Profit per box (- denotes loss) ....................... .183 -.410 .052 .492
Pounds of fertilizer per acre ............................. 1,255 1.060 1,392 1,508
Pounds of fertilizer per tree ........................... 20.43 16.88 21.19 20.81
Pounds of soil amendments per acre ............... 25 133 408 1,103
Pounds of soil amendments per tree ............... .40 2.04 6.21 14.84


All averages in the above columns are based upon the totals for all
groves. All groves were not involved in every item. Where such was the
case, the following figures based upon the actual acreage of the specific
groves involved are given for comparison with your particular grove.

f ---198 8


Costs per acre:
Power and equipment ......... .............
Labor, power and equipment not
separated ...................... ................
Soil amendments ...... ..............
Spray and dust ..................................
Irrigation and drainage ........................
All other costs .......... ............ -...
Returns per acre ....................-.............
Profit per acre (- denotes loss) ..............
Returns per box (- denotes loss) ......
Pounds of soil amendments per acre....
Pounds of soil amendments per tree ....
Yield in boxes per acre ......................
Yield in boxes per tree .......................


I
$6.25


8 $6.25


26
.42


$5.34
7.39'
1.60
3.50
2.52
54.69
-43.45
-.41C
261
4.03
106
1.63


$6.76'
1.72
2.20
3.35
2.87
115.07
14.32
.104
474
7.64
138
2.11


$4.55'
2.71
2.80
6.98
.97
153.54
57.33
.501


114
1.64


*Citrus cost of production investigations, Department of Agricultural Economics,
Agricultural Experiment Station, Gainesville, Florida.
'Part of spray and dust materials included in this item on two groves.
'Part of spray and dust materials included in this item on three groves.
'Part of spray and dust materials included in this item on one grove.


.... .. I . e . .


-L""~"


91 32-33


391 3-84







Annual Report, 1937


Accounts were closed on 31 groves at the end of the 1935-36 accounting
year. At the same time accounts were opened for the 1936-37 accounting
year on 32 groves.

A STUDY OF PRE-COOLING AND OF REFRIGERATION IN TRANSIT
AS AFFECTING COST OF MARKETING, QUALITY
AND PRICE OF CITRUS FRUIT
Purnell Project 235 A. H. Spurlock and C. V. Noble
This project has been completed with the preparation of two manu-
scripts summarizing the results. The first of these manuscripts deals
with Florida citrus prices, by variety, by grade, and by size of fruit, in
five markets for auction sales and in eight markets for f.o.b. sales. An
auction price comparison by variety of fruit for all grades is given in
Table 3, and by grade of fruit for all varieties in Table 4.

TABLE 3.-AVERAGE AUCTION PRICES IN FIVE MARKETS, BY VARIETY OF
FRUIT. (ALL GRADES.)

Variety 1930-31 1931-32 1932-33

Per box Per box Per box
Oranges:
Parson Brown ........................ $3.76 $2.97 $3.20
Pineapple ................................ 3.50 3.46 2.88
Valencia .................................. 3.87 3.77 2.37
Other varieties ...................... 3.23 3.20 2.43

All varieties ......................I $3.58 $3.52 $2.54

Grapefruit:
Marsh Seedless .................. $2.77 $3.10 $2.53
Other varieties ...................... 2.82 2.49 2.37

All varieties ......................| $2.81 $2.67 $2.42

The second manuscript deals with costs of marketing and auction prices
in five markets by route of shipment and by method of preservation used
before shipment and in transit.

TABLE 4.-AVERAGE AUCTION PRICES IN FIVE MARKETS, BY GRADE OF
FRUIT. (ALL VARIETIES.)

Grade 1930-31 1931-32 1932-33

Per box Per box Per box
Oranges:
Supergrade ............................ $4.05 $4.11 $3.52
Grade 1 .................................... 3.68 3.62 2.76
Grade 2 .................................... 3.24 3.27 2.28

Grapefruit:
Supergrade ............................ $3.37 $3.04 $3.49
Grade 1 .................................... 3.04 2.83 2.83
Grade 2 .................................... 2.37 2.37 2.09







Florida Agricultural Experiment Station


The most common methods of preservation used in rail shipments
were pre-cooling and initial icing combined, and standard ventilation (or
no refrigeration). These two methods accounted for 68.6 percent of the
rail shipments during the three seasons studied.
Standard ventilation was used mainly in the cooler months (November
through April), while in the hotter months there was an increased use
of standard refrigeration, and of pre-cooling and initial icing combined.
The last named method was fairly important the year round, as shown
by percentage of total shipments each month.
Average preservation costs to five markets for the three seasons studied
were: for pre-cooling, 9.5 cents per box; initial icing, 10.3 cents; and for
standard refrigeration 19.1 cents per box. Combinations of two methods
of preservation resulted in a cheaper rate than the sum of the two rates
when used independently. For example, pre-cooling and initial icing
combined, 18.1 cents per box; and pre-cooling and standard refrigeration
combined, 27.3 cents per box.
The three-season weighted average cost per box for freight, selling,
and other costs (excluding preservation) for fruit shipped all-rail to New
York was $1.00; to Chicago, $1.07; to Detroit, $1.08; to Cincinnati, $0.94,
and to Pittsburgh, $1.03.
There was no relationship between the method of preservation used
in marketing citrus fruit from the 31 packinghouses studied and the auction
price received when compared monthly. The condition of the fruit when
it arrived for sale on the auction was not known; thus it was impossible
to determine the relative efficiency of the various methods of refrigeration
in preserving the fruit.

A STUDY OF ADJUSTMENTS IN FARMING BY REGIONS AND TYPE-
OF-FARMING AREAS, FROM THE STANDPOINT OF AGRI-
CULTURAL ADJUSTMENT AND PLANNING, INCLUDING SOIL
CONSERVATION
Purnell Project 262 C. V. Noble and Bruce McKinley
In cooperation with Federal Project 1100, AAA and BAE.
Inactive during 1936-37.

FLORIDA TRUCK CROP COMPETITION
Each year a summary is compiled and mimeographed showing the
weekly car-lot shipments of the leading Florida truck crops and the com-
petitive shipments from other states and from importing countries. These
mimeographed summaries keep Florida bulletin 224 up to date. This was
done in 1936 for the 1935-36 crop season.






Annual Report, 1937


AGRONOMY

Investigations of the Agronomy Department for the year have included
breeding and selection work with several field crops, numerous variety,
rotation and fertilizer experiments, fundamental studies of plant growth
and development, introduction and testing of numerous new forages, grains
and grasses, and the initiation of a widely diversified and comprehensive
program of pasture research.

PEANUT IMPROVEMENT

State Project 20 Fred H. Hull and W. A. Carver
Peanut breeding has been continued as previously outlined. One new
objective is a Spanish type peanut having Valencia quality. The breeding
block now contains: (1) 41 plant selections and 19 mass selections of the
older hybrids; (2) 261 fourth generation plant selections and 147 mass
selections from crosses of Dixie Giant, Virginia Jumbo, older hybrid strains,
and Rasteiro by Spanish; (3) seven plant and four mass selections in the
third generation of crosses involving the same parentage as above and
in addition older hybrids intercrossed and Jumbo crossed to older hybrids;
(4) 640 second generation plants of Pearl (Spanish) by Dixie Giant, Pearl
by Rasteiro, and Pearl by older hybrids; and (5) 95 first generation plants
of older hybrids by Pearl, Dixie Giant, and Rasteiro and older hybrids
intercrossed. During the present season, crosses are being made of Florida
Runner by Spanish, Florida Runner by Lovelace which is an extra large
seeded runner peanut, and Valencia by Spanish. One of the older hybrids
of runner type yields 91 percent of Florida Runner and is about two
weeks earlier.
Yield trials were made with standard varieties, introductions and
hybrids.
A spacing test including Spanish, Florida Runner and one of the more
stable intermediate hybrids is being repeated this year, the objective being
to determine the influence of spacing on yield and quality.

PASTURE EXPERIMENTS

Hatch Project 27 W. E. Stokes, G. E. Ritchey
and W. A. Leukel

II. INFLUENCE OF VARIOUS FERTILIZERS ON YIELD OF
PASTURE GRASSES

Yields of dry grass indicate that the reaction of centipede (two years)
and of Bahia (three years) to the application of different fertilizers is
very similar. Lime has shown very little if any influence on yields, while
nitrogen seems to be the limiting element and plots upon which nitrogen
has been applied have shown a substantial increase. Phosphate and potash
continue to produce only slight effects in yield. Samples of the herbage
from the variously fertilized plots are being taken for analysis.







Florida Agricultural Experiment Station


III. COMPARISON OF NATIVE AND IMPROVED PASTURES,
COMPARISON OF BURNED AND UNBURNED NATIVE
PASTURES FOR BOTH NINE AND TWELVE MONTHS'
GRAZING AND A COMPARISON OF METHODS OF LAND
PREPARATION PREVIOUS TO SEEDING IMPROVED PAS-
TURES
(Animal Husbandry Department, State Forest Service and Fore-
most Properties, Cooperating)
Improved pastures of carpet grass again have given greater beef pro-
duction (live weight) per acre than native pastures composed largely of
wire grass, broomsedge and Indian or wild oat. Burned over native
pastures continued to give greater beef production (live weight) than
protected native pastures in both nine and 12 months' grazing tests.
The effect of good seedbed preparation in pasture establishment is
still evident after eight years in that the resultant sod is much more
satisfactory where the best preparation was given the land previous to
seeding. No grasses seeded in 1929 after a burn or in the rough and
grazed and protected thereafter have become established. This indicates
that in seeding pastures on cut-over land it is necessary first to give
sufficient preparation to rid the land of native vegetation.

III-A. EFFECT OF BURNING ON GROWTH AND RELATIVE
COMPOSITION OF RANGE GRASSES
Work on this phase of pasture studies has been enlarged and included
in Bankhead-Jones Project 299.

VALUE OF CENTIPEDE GRASS PASTURES AS AFFECTED BY
SOIL CHARACTERISTICS AND OTHER FACTORS
Special Project 27-A
This project is carried jointly by the Florida Experiment Station, the
Georgia Coastal Plain Experiment Station at Tifton, Georgia, and the
Bureau of Plant Industry, U. S. Department of Agriculture. The object
is to determine why cattle do not thrive on centipede grass pasture at
Tifton, Georgia, whereas on a like pasture at Gainesville, Florida, cattle
make very satisfactory gains.
Samples of the grass, taken at several times during the growing sea-
son, and of the soil of the centipede pasture areas at both Tifton and
Gainesville have been collected for spectrographic and other analyses.
Spectrographic analyses of 50 samples show considerable variation in the
mineral content of the grasses from the two stations.

CROP ROTATION STUDIES WITH CORN, COTTON, CROTALARIA
AND AUSTRIAN PEAS
Hatch Project 55 W. E. Stokes, J. P. Camp
and Geo. E. Ritchey
This season's records complete seven years' data on this work. The
project is being continued with Sea Island cotton being substituted for
Upland cotton. The first five years involved a two-year rotation of corn
and cotton without a leguminous cover crop, and with summer and winter
cover crops alone and in combination.







Annual Report, 1937 37

In 1935 zinc sulfate was applied to one half of each plot at the rate
of 24 pounds per acre and again on the same area in 1936 at the rate of
12 pounds per acre.
Previous to 1936, rotated plots produced decidedly higher yields of
cotton than those cropped continuously to cotton. The use of leguminous
cover crops had little or no influence on yield of seed cotton. There was
a slight gain in yield of seed cotton, however, on all rotated plots treated
with zinc.
There was very little increase in yield of corn as a result of the corn
and cotton rotation, nor was there a significant increase in yield of corn
on the rotated plots of corn which were treated with zinc sulfate.

II. CORN AND RUNNER PEANUTS ROTATING WITH CROTA-
LARIA AND WITH NATIVE COVER CROPS
This phase of the crop rotation project is a long-time study of the
differences in crop responses where corn and runner peanuts are grown
year after year on the same land as compared with such crops grown
alternately and every third year following a rest of the land to native
cover versus a one-year rest of the land to a planted cover of crotalaria.
Yearly yields of corn and peanuts have been less on the continuous corn
and peanut plots than yields of corn and peanuts following one and two
years rest to cover crops. White bud of corn is also less noticeable in
the corn grown in a rotation with cover crops than it is in corn grown
each year on the same land.

VARIETY TEST WORK WITH FIELD CROPS
Hatch Project 56 W. E. Stokes, G. E. Ritchey
and J. P. Camp
COWPEA VARIETY TEST
Twelve cowpea hybrids were grown from seed received from A. E.
Gibson, Director of the Department of Agriculture and Stock, Brisbane,
Australia. Another variety received from the Bureau of Plant Industry,
USDA, known as an "Australian wild cowpea", was grown to compare
with the hybrids. With one exception, the plants are large, rapid growing
strains. They are mostly shy seeders and mature late in the season. They,
however, have some attractive characteristics which may be of value as
breeding stock for an improvement program.

SUGARCANE VARIETY TEST
Some 30 kinds of sugarcane are being grown as stubble canes and out
of this lot a few of the best were selected last fall and planted in larger
quantity for further observations as to syrup yield and quality as well
as for forage purposes. These selected canes are from the cane breeding
work of the Everglades Station and are being compared with commercial
types such as Cayana, CO 290, C.P. 807, Tekcha and Uba.

OAT VARIETY TESTING AND BREEDING
Crown rust is a serious detriment to oat production in Florida. All
oat variety and strain testing is with a view to finding a prolific, early-
maturing oat resistant to this disease. Fulghum and Suwannee County
Blackhull oats are both early but lack resistance to rust. Bond and Victoria
oats are both highly resistant to rust but are too late in maturing to
give good crops when moisture is short in April and May.








TABLE 5.-SUMMARY OF RESULTS OF OATS VARIETY TESTS CONDUCTED DURING 1934, 1935, 1936 AND 1937 BY THE AGRONOMY
DEPARTMENT, MAIN EXPERIMENT STATION, GAINESVILLE, FLA.
Bushels grain per acre.
Approx. 1934-35 1936-37*1
Variety date 1933-34* 1934-35 coop. 1935-36 (Relative Reaction to
__ _Maturity ___tests only) crown rust


Late Varieties














Early Varieties


Appler .......................

Red Rustproof ..........

Bancroft ................

Hastings 100 Bu ......

Alber ..........................

Country Common .....

College Algerian ......

Berger ........................

Bond ............................

Victoria ......................


Fulghum .....................

Suwannee Co.
Blackhull ................

Coker's Fulgrain ......
Coker's 33-50 ..............
Coker's 33-47 ..............


May 21






May 30

May 19




May 22

May 24


May 9

May 4


*Good moisture during growing season.


20.14















21.98


17.54


23.46


15.95






8.24

19.25




12.03

13.86


25.58

22.56


14.96


11.79


25.50

25.32


20.96

21.81


12.10

6.90

10.61.

11.25

3.47

8.21

9.79

3.22

20.00

16.35


Medium

Medium

Medium

Medium

Medium

Medium

Medium

Medium


resistant

resistant

resistant

resistant

resistant

resistant

resistant

resistant


Practically immune

Extremely resistant


2.96 Susceptible

5.78 Susceptible

4.66 Susceptible
3.47 Susceptible
1.41 Susceptible







Annual Report, 1937


Table 5 shows yields of a number of oat varieties for four seasons. The
1934 and 1937 seasons provided sufficient moisture for normal heading
of late varieties while 1935 and 1936 seasons were dry and show the
advantage of earliness under such conditions. The 1937 season was the
most severe rust year of the four and caused practical failure of the early
and rust-susceptible varieties, while the most resistant varieties (Bond
and Victoria) made excellent yields considering the poor soil on which
grown.
Some 600 hybrid oat selections were obtained from the USDA Cereal
Office and planted in the fall of 1936. Most had Bond or Victoria as one
parent. A great majority proved to be very resistant to rust and nearly
100 were selected as sufficiently early and vigorous to warrant further
testing. All of the latter made excellent growth in a field where Fulghum
was almost completely destroyed by rust. The most nearly immune to
rust were Bond x Fulghum hybrids, none of which, however, are quite
early enough.
For the purpose of developing more earliness and at the same time
introducing better agronomic characters, several of these hybrids were
hand pollinated with Fulghum pollen. From these crosses about 250 seed
were obtained.
RYE VARIETY TEST
Florida Black and Abruzzi were the only two ryes in the test this
year and the Florida Black significantly out-yielded the Abruzzi and was
10 days earlier.
Lespedeza sericea VARIETY TEST
Lespedeza sericea F. C. Nos. 04730, 17291 and 19284 were planted on
plots variously fertilized particularly as to rates of phosphate. All failed
due to the stand being killed by dry weather soon after germination of
the seed. The test is being repeated this season.

GREEN MANURE STUDIES
State Project 98 W. A. Leukel and G. E. Ritchey
Triplicated plots of Crotalaria intermedia, C. spectabilis and C. striata
and natural vegetation are cropped every other year to corn, allowing the
crotalaria to reseed each year. One year's corn yields have been obtained.
This series of plots is being grown to the crotalarias and native vegetation
this year.
Beginning with the season of 1936 the experiment was extended to
include duplicated plots receiving the same treatment on another field,
thus allowing a greater replication. The crotalarias and native vegetation
were grown in 1936 and the first crop of corn was grown this year.
Work included under this project will hereafter be reported as a phase
of Hatch Project 55.

IMPROVEMENT OF CORN BY SELECTION AND BREEDING
Purnell Project 105 Fred H. Hull and W. A. Carver
Field Corn: Variety tests were continued with 27 common varieties at
the Main Station and 23 varieties at the North Florida Station. The tests
at Quincy included corn alone and interplanted with velvet beans.
The method outlined previously of improving existing corn varieties
by combining prepotent inbred lines with them has continued to appear
promising. A stock of 75 percent Whatley and 25 percent weevil-resistant
lines is being subjected to mass selection at Gainesville and Quincy and
by some 15 farmers in their own fields. This stock was included in the







Florida Agricultural Experiment Station


variety tests at Gainesville and Quincy in 1936 and 1937. In both yield
and weevil resistance it averages about midway between Whatley Prolific
and the best non-prolific, weevil-resistant native varieties. Another stock
which is 75 percent Erck Yellow Flint and 25 percent highly prolific inbred
lines averaged about 15 percent greater yield than Erck Yellow Flint or
Cuban Yellow Flint and showed a little more weevil damage. It is be-
lieved that the yield of this stock can be increased considerably by selec-
tion of two and three-eared plants to produce a prolific variety that is
yellow, flinty, and husk-protected. Inter-breeding of two- and three-eared
plants only has been done by hand pollination in a plot at Gainesville
in 1937.
Breeding by selection in inbred lines and recombining them in hybrids
has been continued as previously described. Two hundred double crosses
of inbred lines selected by appearance alone were tested last year. They
are compared with Whatley Prolific, the highest yielding commercial
variety in Florida tests. Whatley suffers about twice as much weevil
damage as the best native varieties. Rating Whatley at 100 percent,
the average rating of double crosses was: yield sound corn 113 percent,
weevily ears 68 percent, sound eari 104 percent, erect plants at harvest
time 188 percent, and prolificacy 88 percent. Thirty-nine of the double
crosses grown at Quincy averaged: yield sound corn 100 percent, weevily
ears 62 percent, sound ears 107 percent, erect plants 243 percent, and
prolificacy 82 percent. Many inbred lines in this first set of double
crosses are now being discarded because of poor records in top cross
tests on Whatley Prolific, and other lines that have made good cross
records are being included in double crosses. Strong correlation between
top cross and double cross performance is evident. Four hundred new
double crosses are being tested along with a number of those in the
1936 test.
Sweet Corn: Variety tests were conducted with principal commercial
sweet and roasting ear corns and a number of new sweet varieties bred
here and elsewhere in recent years. One test was made under field condi-
tions and another in the horticultural gardens with irrigation and heavy
fertilization. Tabular summaries were mimeographed and distributed.
Golden Cross Bantam sweet corn, a cross of two inbred lines of Golden
Bantam, has produced satisfactory crops of high quality under garden
conditions.
The best selections in Sweet Snowflake made on the basis of tenderness
and flavor were combined in 1936 and the combination is being grown in
tests and an increase plot in 1937. It is believed that this selected lot
will prove satisfactory for release without further selection.
A project to recover the excellent table quality of Golden Cross Bantam
in a large vigorous strain of Southern type is being continued. It has
been demonstrated that the intensity of selection being practiced will
retain much of the Southern type and that the quality recovered simultan-
eously in the second backcross to Golden Cross Bantam is very near to
that of Golden Cross Bantam itself.

FERTILIZATION OF PASTURE AND FORAGE GRASSES
Hatch Project 120 W. A. Leukel and J. P. Camp
The major work in this project has been completed and reported in
Bulletin 269. Some preliminary observational work on the effects of
high and low rates of different forms of nitrogen fertilizers-nitrate of
soda, ammonium sulfate, and cyanamid-were undertaken. When applied
during dry weather the greatest burning effects were noted from high







Annual Report, 1937


applications of nitrate of soda. Cyanamid showed some burning of the
blade tips of the grass as a result of the material adhering to the leaves
when wet with dew. Ammonium sulfate showed no burning effect. Vig-
orous growth resulted from the nitrogen application in each case.
Substitution of commercial fertilizers in place of sewage effluent as
reported in Bulletin 215 from this station was tried on Napier grass.
They failed to produce lasting growth response in the grass when fertiliza-
tion was discontinued.
Many phases of the above work are being continued in another project
(No. 295, Bankhead-Jones), and therefore to prevent duplication this
project is being discontinued.

CORN FERTILIZATION EXPERIMENTS
State Project 163 J. D. Warner, W. E. Stokes
and J. P. Camp
A cooperative corn fertilizer formula and source of nitrogen experi-
ment is being concluded on a Norfolk sandy loam soil in Jackson County
and on a Ruston sandy loam soil in Calhoun County after four and five
years' study, respectively. These experiments occupy different plots each
season and have covered a total of 20 to 25 acres at each location. Results
clearly show nitrogen to be the first limiting factor in yield on Norfolk
soil. Slight but consistent increases in yield have followed applications
of phosphate and potash. On the Ruston sandy loam soil the role of
phosphate is equally as important as that of nitrogen. Potash also stimu-
lates yield to a considerable extent. In each experiment, where a complete
fertilizer was supplemented by an application of 15 pounds per acre of
zinc sulfate, the increase in yield has been about 2 bushels per acre.
Eight sources of nitrogen were compared on each soil type. Results
indicate that all inorganic sources in these trials have been approximately
equal in efficiency. During extremely dry seasons, as prevailed in 1936,
inorganic sources have been decidedly more efficient than organic sources.
Seven years' work on sources of nitrogen for corn with and without
phosphate and potash at Gainesville on Norfolk medium fine sand, using
Whatley Prolific corn, has been completed and the results are given in
Table 6.
TABLE 6.-EFFECT OF DIFFERENT SOURCES OF NITROGEN ON CORN YIELD.

Bushels of corn per acre
Sources of nitrogen without phosphate with phosphate
and potash and potash
N one ......... .................. ............... 13.3 16.6
Cottonseed meal ............................ 19.3 22.3
Nitrate of soda .......................-.... 15.6 20.5
Sulfate of ammonia ...................... 19.4 22.4
Leunasalpeter* .............................. 19.7 23.9
Calurea ............... ................... ...... 19.3 22.1
U rea ................................................ 18.7 22.3
Calcium nitrate .............................. 17.7 22.3
*Calnitro substituted for leunasalpeter in 1936 as leunasalpeter not
available.

The sources of nitrogen test on corn at Gainesville is being continued.
A fertilizer test on corn on land which commonly produces white bud
corn is being run at Gainesville after treating the soil uniformly with
zinc sulfate for the prevention of white bud. Fifteen fertilizer formulas
at a basic rate of 200 pounds per acre are being tested in 16 replications.







Florida Agricultural Experiment Station


A STUDY OF CROTALARIA AS A FORAGE CROP
State Project 174 W. E. Stokes and G. E. Ritchey
This project has been completed and a report of the findings is being
prepared for publication.
A STUDY OF CHLOROSISS" IN CORN AND OTHER
FIELD CROP PLANTS
Adams Project 220 R. M. Barnette, J. P. Camp
and J. D. Warner

Field work has continued in cooperation with the Department of Chem-
istry and Soils to include study of the residual effect of zinc sulfate applied
to the soil and to test the effectiveness of different sources of zinc in pre-
venting white bud of corn. A detailed report on this project will be found
in the report of the Department of Chemistry and Soils.

A STUDY OF THE DEVELOPMENT AND DETERIORATION OF ROOTS
IN RELATION TO THE GROWTH OF PASTURE PLANTS GROWN
UNDER DIFFERENT FERTILIZER AND CUTTING TREATMENTS
Adams Project 243 W. A. Leukel
Roots of plants kept in a vegetative growth condition through frequent
cutting over a period of three years were consistently lower in weight than
those of similar plants grown to maturity. The similarity of weight of
these differently treated plants in the spring and fall in each instance
indicated (as observed from the growth cycle of the plants) the growth
of a new root system each season and the deterioration of the old one.
Differences in composition of the roots of these differently treated
plants in the spring and fall when dug are not so marked as those of
the top growth of frequently cut plants. Nitrogen appeared slightly higher
than in the roots of plants grown to maturity. The relation between carbo-
hydrates and nitrogen was slightly narrower in the roots of frequently
cut plants. Stolons, closely related in growth to that of the roots, showed
very little variation in composition under different treatments. This in-
dicates that the residual leafage on the frequently cut plants is sufficient
for the elaboration of organic foods for continuous vegetative growth.
Some progress has been made on the measurement or determination
of reducase in the roots and other parts of pasture grasses. Reducase is
instrumental in the reduction of nitrates. Preliminary work thus far
indicates a greater reduction of nitrates in the roots and stolons of fre-
quently cut plants than in similar parts of pasture plants grown to
maturity. A further refinement of procedure used in these determina-
tions is under way.
A further prerequisite for the reduction of nitrates in the roots of
the plants appears to be a sufficient supply of available phosphorus. This
element appears essential for the activity of reducase. The oxidation and
building up of the reduced nitrates to proteins appears to be dependent
upon or associated with available potassium.

COMPOSITION FACTORS AFFECTING THE VALUE OF SUGARCANES
FOR FORAGE AND OTHER PURPOSES
State Project 265 W. A. Leukel
Growth and composition studies were made on Cayana cane from the
period of early growth in spring until early fall. Green leafage gradually







Annual Report, 1937


increased from the early growing season (June and July) but after early
fall (September) the weight of green leafage gradually declined. Weight
of stalks gradually increased during the entire growing season and reached
a maximum when the last plants were dug in early fall (October). Root
weight showed a gradual increase during the entire growing season.
In the green leafage, soluble forms of nitrogen are highest on a per-
centage basis in the early part of the season and slightly decrease as
the growing period advances. The unextracted and protein forms of nitro-
gen and total nitrogen also gradually decrease toward the latter part
of the growing season.
In stalks the decrease in percentage of different forms of nitrogen
is more marked toward the close of the growing season than that of the
leaves. On the other hand, the roots show a decrease in percentage of
soluble forms of nitrogen and an increase in percentage of unextracted,
protein and total nitrogen toward the latter part of the growing season.
Sugars show a marked variation in the different parts of the plant.
In the leaves sugars gradually increase, reaching the highest level in
the fall. In the stalks the sugars increase almost threefold and in the
roots double from June to October. Soluble starches, dextrins and starches
are present in only small quantities. Hemicelluloses show no regular
variation during the season. Unhydrolyzed residue in the different plant
parts shows no regular trend through different growth periods.
The increase in carbohydrates in the form of sugar instead of higher
carbohydates as this plant approaches maturity should make it a more
desirable plant for forage purposes. The increased elaboration of carbo-
hydrates during the season with a decrease of green leafage per plant
indicates a greater photosynthetic capacity of the leafage as the growth
period proceeds. This increased carbohydrate elaboration is not only
reflected in the leaves and stalks but also in the roots. Decrease in per-
centage of nitrogen in stalks late in the growing season is reflected in
increased nitrogen content of roots as a result of translocation of this
element downward.
PASTURE STUDIES
Bankhead-Jones Project 267 W. E. Stokes and A. L. Shealy
The comprehensive outline of pasture investigations included under
this number has been broken down into several sub-projects which are
reported under Bankhead-Jones numbers 295-304, inclusive. Much further
preliminary work has been completed, including land clearing, fencing,
drainage and installation of field and irrigation equipment.

THE EFFECT OF FERTILIZERS ON THE YIELD, GRAZING VALUE,
CHEMICAL COMPOSITION AND BOTANICAL MAKE-UP
OF PASTURES
Bankhead-Jones Project 295 R. E. Blaser and W. E. Stokes
Five predominating soil types on which improved pasture grasses had
already been established have been top-dressed with 36 different fertilizers
designed to show possible growth increases from both primary and sec-
ondary plant nutrient elements. The possibility of developing a uniform
and high yielding growth curve with nitrogen fertilization is under con-
sideration. Pasture fertilization economy as related to frequent heavy
or infrequent light applications and various rates of the major nutrient
elements is to be determined. The alteration of the pasture vegetation
and feeding quality of herbage as changed by fertilizer is to be observed.







Florida Agricultural Experiment Station


The soil of each plot was sampled at two depths before any fertilizer
treatments were given and will be sampled at intervals throughout the
experiments. The Chemistry and Soils Department is handling the soil
chemistry studies in the experiment.
These various fertilizer treatments are laid out in field plots 7x20 feet,
replicated four times in randomized blocks. Yield data are obtained by
cutting a 20-foot strip of grass 25 inches wide on the center of each plot.
The grasses are clipped with a frequency to maintain a vegetative growth
condition. Green and dry weight records are kept on all plots and samples
of the herbage are retained for chemical analyses.

ERADICATION OF WEEDS IN TAME PASTURES
Bankhead-Jones Project 296 R. E. Blaser
Areas for eradication studies on two weed pests, a thistle (Cirsium
nuttallii) and dog-fennel (Anthemis cotula), have been selected. Eradica-
tion experiments with herbicides, cutting, spudding and cutting with a
rotary palmetto cutter have been started. Because of the biennial growth
cycle of these two weed types, the economical method of eradication is
prevention of seed production. Data gathered thus far indicate that
cutting two inches above the ground or lower after blooming and previous
to seed production will exterminate most thistle plants. Cutting treat-
ments between the rosette and pre-bloom growth cycle diminished the
plant size, but did not prevent seed production.
Eradication work on other weeds common in improved pastures will
be inaugurated as the season prevalence of various types is approached.

FORAGE NURSERY AND PLANT ADAPTATION STUDIES
J Bankhead-Jones Project 297 Geo. E. Ritchey and W. E. Stokes
SHatch Project 107
These projects have been carried as one during this fiscal year, but
hereafter the work will be reported under Project 297.
The study of introduced and native plants has been enlarged and con-
tinued. During 1936, 231 plantings of foreign introduced material were
grown for observation, 98 of these for the first time in the garden at
Gainesville. In addition more than 600 collections from native plants
were grown under cultivation and observed for possible forage purposes.
Included in the plantings for foreign introduced plants were 13 Digitaria
sp. which had been introduced from Southern Africa and which are often
referred to as "Woolly Finger grass". With the exception of S.P.I. No.
111,128 none of the new species look more promising than D. eriantha var.
stolonifera or D. pentzii, which have been grown and reported on in
previous years.
Three or four species of the native grass collections look promising.
One native legume is also receiving special attention as a possible com-
panion crop with summer pasture grasses.
The long leaf centipede (Eremochloa ophiuroides) S.P.I. 72260, Digitaria
eriantha var. stolonifera and D. pentzii are all making fair growth in
partially shaded hardwood hammock areas.
CLOVER ADAPTATION STUDIES
Twelve species of clovers (Trifolium spp.) were planted in flower pots.
Soil consisting of rotted manure, clay and sand was mixed in the propor-
tion of 2-2-1, respectively. All pots were fertilized with phosphate, lime
and potash and inoculated with cultures of nodulating organisms isolated







Annual Report, 1937


from several different species. The growing plants in these pots were
transplanted in protected areas on sods of mixed grasses. Best growths
were obtained on Trifolium clypeatum, T. compestre and T. resupinatum.
A more desirable tract of land has been secured for adaptation studies
and the 1937 nursery garden has been planted in this area. About 1,000
plantings are under observation.

FORAGE AND PASTURE GRASS IMPROVEMENT
Bankhead-Jones Project 298 Geo. E. Ritchey and W. E. Stokes
NAPIER GRASS (Pennisetum purpureum Schumach)
In 1934 and 1935 a field of Napier grass which had been used in a
fertilizer test on the Station farm was killed by a disease known as
eyespott", Helminthosporium ocellum Faris. By the spring of 1936 only
12 vigorous plants were growing in the field. These 12 plants were re-
moved and planted in a plant-to-row order with diseased plants in alternate
rows. In the spring of 1937 R. K. Voorhees of the Department of Plant
Pathology made greenhouse inoculations of all selections. Only one strain
succumbed to the disease. All others remained healthy.
Plantings were made in February of about 1,000 samples of vegetative
pieces and 1,000 seed heads which were collected at random from Napier
grass plants growing in the wild state in the Everglades. A large number
of types and combinations of characters are resulting from these collections.
Over 3,000 individual plantings are under observation and from these
desirable planting material will be selected. Some of the most desirable
selections are now being grown in increased plantings.

CENTIPEDE GRASS (Eremochloa ophiuroides (Mumo) Hack)
Seed of centipede grass is viable and will grow readily. Centipede
plants produce an abundance of seed heads but most of the glumes remain
empty and therefore the plants are scanty seeders. There seems to be
considerable variation among individual strains in quantity of seed pro-
duced. Since it is desirable to have a good strain of centipede grass
which produces plenty of viable seed, several hundred seedlings of seven
strains have been transplanted into the field to determine how much
variation may be expected in growth and seeding habits of the different
plants. If favorable variations are frequent enough to justify it the
work will be enlarged to include a larger number of plants for breeding
studies looking toward good grazing type plants which seed well.

GROWTH BEHAVIOR AND RELATIVE COMPOSITION OF RANGE
GRASSES AS AFFECTED BY BURNING AND THE EFFECT OF
BURNING ON MAINTENANCE OF NATURAL GRASS STANDS
AND UPON THE ESTABLISHMENT OF IMPROVED GRASSES
Bankhead-Jones Project 299 W. A. Leukel and W. E. Stokes
Work under this project was undertaken following preliminary work
on the effect of burning on the composition and growth behavior of range
grasses. Burning reverted the plants to a vegetative growth condition,
higher in protein and essential minerals in relation to carbohydrates and
fibrous woody materials. On the other hand, grasses not burned over
remained low in nitrogen and essential minerals and were high in carbo-
hydrates and fibrous woody materials. The former growth condition pre-
vailed for a period of three months or more, after which the grasses again







Florida Agricultural Experiment Station


became mature and acquired the composition balance of the latter. Plants
not burned over showed some vegetative growth late in the season after
the old growth became matted closer to the ground but this growth con-
dition was of short duration.
The above results indicate that periodic burning of part of the range
at monthly intervals might keep grasses in a vegetative growth condition
over a longer period. This should provide a better herbage with a more
favorable composition balance. On the other hand, burning at different
periods might not always result in the same growth vigor of the after-
growth. Old growth on the range shades any new vegetative growth
coming up underneath the old grass cover. Since these new grasses are
obstructed from the full sunlight their capacity for organic food elabora-
tion is likewise hindered. As a result of this condition, most new growth
is produced at the expense of the previously stored organic foods in the
lower plant organs. If at some period of the season, these lower organs
are sufficiently depleted, a much weaker and sparser after-growth might
occur after burning at this particular period. This condition should afford
an opportunity for the seeding, germination and growth of carpet or some
other tame pasture grass on the range without 'being crowded out by the
native range grasses. This condition for favorable growth may not occur
by late burning of the range the first time. Several such burnings may be
required during one year or during successive years with this object in
view. Periodic burnings during the year are to be made on the range
after no rest, and after a rest (protection from fire) of one, two, three
and four years.
The above objectives are to be sought in an experiment established
on an area of representative range land located on the Austin Cary
Memorial forest area. An eight acre tract has been laid out into five
equal sections, each containing 65 plots. The equivalent of one section
is to be utilized for each treatment, namely, burning without rest, and
after one, two, three and four year rest periods. For each of these
different treatments five representative plots are to be burned over at
monthly intervals throughout the year for each treatment and time period
specified. Five plots in each instance are to remain unburned. For each
treatment samples of grass are taken from the area to be burned each
month and also each month following this burning treatment. Samples
from the check plots are taken likewise in each instance. Seeding of tame
pasture grasses will be undertaken wherever growth conditions of native
grasses after burning warrants such procedure.
Laboratory determinations thus far indicate a vegetative growth condi-
tion of the native grasses after burning in each instance, i. e., such grasses
are higher in nitrogen and essential minerals and lower in carbohydrates
and fibrous woody materials. After a period of three months or more
these grasses become mature and show a composition relation similar to
the older grasses from the unburned areas, i. e., they are lower in nitrogen
and essential minerals and higher in carbohydrates and fibrous woody
materials.

METHODS OF RIDDING LAND OF OBJECTIONABLE GROWTHS
AND OBSTACLES

Bankhead-Jones Project 300 R. E. Blaser and W. E. Stokes
A large portion of Florida land suitable for permanent pasture or
cropping is now occupied by wire grass (Aristida spp.), saw palmetto
(Serenoa repens), gallberry (Ilex glabra), running oak (Quercus pumilla)
and other woody plants. Economical eradication methods must be found







Annual Report, 1937


before the land covered with these objectionable growths will be most
profitably utilized.
Methods for exterminating these species by burning, cutting and her-
bicide (chemical) treatments alone and in various combinations are being
tested. These treatments are repeated at monthly intervals to determine
the critical period of extermination. Close observation also is being made
of results attained with various brush and weed cutting machines now
being used in the attempt to rid land of objectionable growths previous
to seeding pasture grasses.

PASTURE LEGUMES
Bankhead-Jones Project 301 W. E. Stokes, G. E. Ritchey
and R. E. Blaser
Trials are being made with legumes in the attempt to find one or more
that may be grown successfully in pastures as a companion to the better
grasses, or to determine a system of management of pastures which will
make the growing of such legumes possible.
In 1936 and 1937 10 series of plots were treated with fertilizers vary-
ing in superphosphate content from 0 to 2,000 pounds per acre and con-
taining quantities of muriate of potash and nitrogen-carrying materials.
The effect of lime also is being tested. Some plots are located on pastures
of carpet grass, others on Bahia, some on centipede and others on cul-
tivated areas seeded to the legumes without grasses.
Twenty-five species of clovers in 1936-37 have shown no noticeable
differences between different fertilizer or lime treatments. Persian clover
(Trifolium resupinatum) was the only legume which produced growth
of any importance. The experiment will be repeated next season.
One native legume (Meibomia supina) is being seeded in pasture areas.

A STUDY OF NAPIER GRASS (Pennisetum purpureum) FOR PASTURE
PURPOSES
Bankhead-Jones Project 302 R. E. Blaser, W. E. Stokes
and A. L. Shealy
The normal yield curve of the present permanent pasture grasses
reaches its culmination during the summer rainy season, with a reduced
amount of herbage during other periods of the year. It is possible that
the normal yield curve can be levelled by utilizing supplementary grazing
crops.
Work on utilizing Napier grass for both permanent and supplementary
pasture crops has been initiated. Five blocks of three acres each have
been planted to Napier grass for grazing work.
Sufficient quadrats for Napier grass production records and grass
consumption by the grazing animals are maintained in each 3-acre block
of Napier grass. Steers are used to measure the carrying capacity and
forage value of the grass.
This project is in cooperation with the Animal Husbandry Department.

WATER PASTURE STUDIES
Bankhead-Jones Project 303 G. E. Ritchey and R. E. Blaser
The object of this project is to make grass and other plant adaptation
studies of areas which are covered with water throughout all or a portion
of the year. During the season of 1936-37 a number of species of rice
have been grown in such wet areas, but none so far has been able to







Florida Agricultural Experiment Station


persist through the winter months. Other plants also have been put in
on wet and water covered areas, and more extensive plantings are planned.

METHOD OF ESTABLISHING PERMANENT PASTURES UNDER
VARIOUS CONDITIONS

Bankhead-Jones Project 304 R. E. Blaser
Several hundred field plots for evolving methods of growing a good
carpet grass grazing turf in a short time have been laid out as cooperative
experiments on two ecological areas. Several methods of planting and
fertilizing centipede grass are being tested. The relationship of different
rates and formulas of fertilizers on rapid production of good grass sods
of various poorly sodded grasses alone and in mixtures is to be determined.
The studies carried include fertilization, cultural operations, manage-
ment practices, seeding methods, and various ways of establishing sods
of grasses that must be propagated vegetatively.
The objectives are: (1) to determine whether desirable pasture grasses
and legumes will replace the inferior native vegetation by fertilizer and
management practices alone, (2) to compare yield and feeding value of the
herbage of the improved pastures with the native vegetation, (3) to find
the most economical fertilizer and cultural practices for establishing de-
sirable pasture grasses, (4) to determine the possibility of developing
high yielding winter grass and legume pastures, and (5) to make adapta-
tion studies of various grasses and legumes in different localities.

SPACING AND PLANT COMPETITION IN COMMON FIELD CROPS
State Project 312 J. P. Camp
The purpose of this project is to investigate the relations of spacing
(area of ground per plant) to the production and quality of field crops,
and include the relations between interplanted crops such as in the com-
bination of corn and peanuts, etc.
In the 1935-36 season a preliminary test with Suwannee Blackhull
oats indicated the importance of a careful study of the rate of seeding.
A more complete experiment in the following season failed because of
a combination of poor soil and severe rust attack.
Three field experiments were successfully completed in 1936 on the
spacing of Whatley corn. Data were obtained on the yield, ear weight
and bushel weight for various spacings of single-plant hills in four-foot
rows. An analysis of the data showed that maximum yields were obtained
in two fields at a spacing of about 10 sq. ft. per plant (19.7 and 22.7
bushels per acre) and in the third at about 9 sq. ft. (30.0 bushels).
Two field experiments involving four varieties of corn are in progress.
Preliminary work is also being done with Sea Island cotton and sugarcane.
The spacing of peanuts is included in another project.

MISCELLANEOUS

STACK SILO EXPERIMENTS
Sugarcane ensilage placed in a stack silo in November 1934, and com-
pletely covered over with soil to a depth of two feet and opened on one
end in April 1936, was completely uncovered June 30, 1937, and found
to be in satisfactory condition except for some spoilage adjacent to the
old opening.






Annual Report, 1937


COMPARATIVE PRODUCTION OF SEVERAL SILAGE CROPS GROWN
AT RELATIVELY HIGH FERTILITY LEVELS
Napier grass, Cayana sugarcane, sorghum (Texas Seeded Ribbon Cane)
and corn followed by cat-tail millet as the corn is cut are being compared
as silage crops. All are grown on the same kind of soil and with the
exception of cat-tail millet are given initially the same kinds and amounts
of complete fertilizer, followed by side applications of fertilizer, particu-
larly nitrogen, as each crop indicates by its growth that fertilizer is
needed. Each crop does not necessarily receive the same total amount
of fertilizer. The yields of green material in tons per acre the past
season were Napier grass 35.1, Cayana sugarcane 23.8, sorghum 7.2, corn
1.9, and cat-tail millet following corn failed. Total pounds of nitrogen,
phosphorus and potassium per acre applied to each crop were as follows:
Napier grass 78-26-26, Cayana sugarcane 78-26-26, sorghum 68-16-16, corn
38-16-16, and cat-tail millet none.

CHUFA FERTILIZER AND SPACING TEST
Fertilizer and spacing tests with chufas gave fair yield responses to
fertilizer as well as to close spacing.
SEA ISLAND COTTON
Cooperation has continued with the Office of Cotton and Other Fiber
Crops and Diseases of the USDA in growing and maintaining reserve
supplies of Sea Island cotton seed of the Seabrook variety. A variety and
place effect test of Sea Island cottons and a fertilizer experiment involving
15 different fertilizer treatments replicated 16 times is under way. Two
acres of Sea Island cotton are being grown for the use of the Bureau of
Entomology and Plant Quarantine in boll weevil control studies. Two strains
of Seabrook Sea Island cotton, involving 15 acres, and 12 selections from
the Seabrook variety are being grown at the Leesburg Laboratory. The
12 selections are being selfed for further breeding purposes.
Two strains of Sea Island cotton, S. I. 36-13 B 3, '34, and Puerto Rican,
are growing at the West Central Florida Station in two isolated fields
of two acres each.
Approximately 50 acres of Sea Island cotton of the Leesburg Seabrook
seed is being grown by individual farmers of Lake County under agree-
ment as to careful handling of the crop and seed so as to make such seed
available as pure stock for future plantings.
COLLOIDAL PHOSPHATE TEST ON SPANISH AND
RUNNER PEANUTS
A preliminary test is being conducted using waste pond (colloidal)
phosphate at the rate of 300, 600 and 900 pounds per acre with and with-
out potash at several rates under both Spanish and runner peanuts.






Florida Agricultural Experiment Station


ANIMAL HUSBANDRY
Animal husbandry research includes projects in the following main
divisions: (1) dairy husbandry and nutrition, (2) beef cattle, sheep and
swine, (3) veterinary investigations, and (4) poultry husbandry. Dairy
cattle, beef cattle, sheep and swine are maintained so that uniform groups
of experimental animals are available for projects dealing with these
classes of livestock. A flock of poultry also furnishes birds for experi-
mental studies. Detailed records are kept on the breeding, feeding and
management of these herds and flocks.
THE DAIRY HERD
The dairy herd consists entirely of registered Jerseys and is located
at the Main Station. The herd serves as the source of cows and young
animals for specific experimental studies of feeds and nutrition, manage-
ment, breeding and transmission of dairy qualities.
When cows pass their usefulness in the herd, they are assigned to
a project on "conformation and anatomy of the dairy cow in relation to
milk and butterfat production".
Ten cows qualified for the Register of Merit on two milkings daily as
a regular part of the measure of transmitting ability of sires and dams.
Eight of these are daughters of the senior herd sire-Sophie 19th's Victor
81st 331031. These are as follows: A .-n. rr 4 .4.n+,
Milk Tt. BJ vrf~t.


Florida Wonder Heart 839769 ............
Florida Victor Marie 1006291 ............
Florida Victor Lavender 1006293 ......
Florida Victor Sophie 1006296 ..........
Florida Victor Hope 1006294 ..............
Florida Victor Agnes 1021788 ............
Florida Victor Buttercup 1021790 ....
Florida Victor Lassie 1021791 ............
Florida Victor Fancy 1021792 ............
Eminent Jubilee Peggy 1037952 ..........


yrs. mos. pounds
7 4 8,068
2 11 6,398
2 8 7,290
2 8 6,586
2 2 7,139
2 4 5,615
2 2. 6,179
2 2 7,051
2 1 6,511
2 2 6,883


percent pounds
5.32 429.35
5.32 340.23
4.87 354.98
5.83 384.19
5.13 366.56
6.00 336.95
4.83 298.58
4.83 340.83
5.17 336.57
5.10 350.88


An analysis was made of the transmitting ability of the seven Jersey
herd sires in service during the past 19 years. All production records
of the daughters were compared with records of their dams at correspond-
ing ages. Eighty-two daughter-dam pairs involved in this analysis are
as follows:
JERSEY BULLS PROVED AT THE FLORIDA STATION BY DAUGHTER-DAM
COMPARISONS, 1919-1937. Percentage of daughters
Bull Daughter-dam Yearly production that increased in
pairs milk test fat milk test fat
No. 1 Daughters ....... 17 6,241 5.14 314 59 76 65
Dams ................ 17 5,740 4.89 281
No. 2 Daughters ........ 9 5,855 5.11 297 33 78 44
Dams ................ 9 6,415 4.84 308
No. 3 Daughters ........ 16 5,953 5.30 323 50 88 81
Dams ................ 16 5,893 4.92 278
No. 4 Daughters ........ 11 5,637 5.23 296 64 64 55
Dams ............. 11 5,053 5.01 275
Nn nnlr-hters 11 4.204 5.20 224 55 82 55


Dams ....-........... 11
Daughters ........ 8
Dams .................. 8
Daughters ........ 10
Dams .................. 10


5,037 5.00 256
2,956 5.57 169
6,199 5.03 312
6,792 5.08 344
4,983 5.44 264







Annual Report, 1937


BEEF CATTLE HERD
A purebred herd of Herefords and Aberdeen-Angus is kept for experi-
mental and instructional purposes. The station also maintains a herd
of native cows on which purebred Hereford sires are used in studies of
herd improvement. Several first and second-cross female offspring have
been obtained. The native and grade herds are used in winter feeding
studies, which have shown that the breeding herd of beef cattle may be
wintered economically and satisfactorily by feeding 2 to 2 pounds per
head daily of cottonseed cake on pasture.

SHEEP

A flock of sheep consisting of purebred Hampshires, grade Hampshires
and natives is kept for studies in fleece and mutton production. These
animals are available for use in laboratory classes in sheep production for
students in the College of Agriculture.

SWINE HERD
Purebred herds of Poland China and Duroc-Jersey hogs are used to
furnish suitable animals for research work in feeding, nutrition, and swine
disease investigations, and for instructional purposes. Experiments are
in progress to determine the value of various grazing and fattening crops.
The mineral deficiencies of peanuts and the nutritional value of grapefruit
meal are being investigated.

THE NUTRITION LABORATORY
Analytical phases of the department's investigations were continued.
Proximate and mineral analyses were made of routine samples from feed-
ing trials, and of forages and silage samples in the studies of Florida
forage crops.
Blood samples were analyzed for such constituents as hemoglobin,
calcium and phosphorus in connection with the investigations of mineral
deficiencies in cattle rations, and the nutritive properties of peanuts for
swine. Red cell volume, erythrocyte counts, reticulocyte counts, icteric
indices, and total leucocyte counts were made from samples of blood of
experimental animals under several conditions.
The rat colony, established in September 1936, was used in a preliminary
assay of dried citrus pulp for vitamin A. A limited number of animals
was used in the study of the nutritive properties of milk as affected by
mineral supplementation, and in the study of a rickets-like condition in
calves. These studies parallel the large animal experimentation.
Forage and animal tissue samples for studies in mineral metabolism
were prepared for spectrographic analysis.
Samples of bamboos from Tibet and from Florida were analyzed to
determine the possible usefulness of the latter in the nutrition of the
Giant Panda, a single specimen of which is at the Brookfield Zoological
Garden in Chicago. This specimen is the only one in captivity. Little is
known concerning food habits of the Giant Panda. Their native habitat
is the bamboo forests of the mountainous areas of Tibet, where the adults
are presumed to subsist almost wholly on bamboo.
Chemical analyses of shark by-products were begun, looking to greater
utilization of these products as supplementary feeds for animals and
poultry.







Florida Agricultural Experiment Station


VETERINARY LABORATORY
Some of the pathological conditions found responsible for livestock
losses during the past year include enzootic bronchopneumonia, coccidiosis,
infectious diarrhea, blackleg, anaplasmosis, trichomonad abortion, infectious
bulbar paralysis (mad itch), parasitic and nutritional anemia, and plant
poisoning of cattle; brucella infection, hog cholera, necrotic enteritis, swine
erysipelas, cocklebur and Crotalaria spectabilis poisoning and nutritional
anemia in swine; hypocalcemia of sheep; and equine infectious anemia.
Malignant jaundice or biliary fever of dogs due to the tick-borne
Haemosporidian, Babesia canis, was reported for the first time in the
continental United States. Equine infectious anemia, due to a filterable
virus, was diagnosed by means of inoculation of susceptible horses under
controlled conditions. Erysipelothrix rhusiopathiae, the causative bacterial
agent of swine erysipelas, was isolated from the spleen of a feeder hog
which was one of a consignment shipped from the middle Western states
to a point in central Florida.
The prevalence of parasites in birds sent to the laboratory for diagnosis
continues to stress the importance of intestinal parasitism of chickens.
Experimental work on fowl paralysis, leukemia and allied conditions con-
tinued to show the importance of intestinal parasites in connection with
the development of these diseases. Experiments are in progress to de-
termine better means of controlling intestinal parasites of chickens.
POULTRY INVESTIGATIONS
The poultry flock is being developed to furnish birds for experimental
purposes and to provide breeds and varieties of poultry for teaching
purposes. Breeds included are: Single Comb Rhode Island Reds, Single
Comb White Leghorns, Barred Plymouth Rocks, Single Comb Buff Leg-
horns, Single Comb White Minorcas, and Silver Laced Wyandottes. All
birds have been tested for pullorum disease and the flock is now in the
National Poultry Improvement Program sponsored by the U. S. Depart-
ment of Agriculture. This plan is administered in this state by the State
Livestock Sanitary Board at Tallahassee.


Fig. 1.-New poultry laboratory building.







Annual Report, 1937


The poultry flock has been increased to provide sufficient birds to con-
duct the various experiments in progress. During the spring of 1937,
2,877 chicks were hatched.
The breeding flock is composed primarily of Single Comb White Leg-
horns and Single Comb Rhode Island Reds, there being two strains of
each breed. Complete records of production, egg size, hatchability, and
livability are kept on these birds.
Projects on feeding and management of chicks, laying birds, turkeys,
breeding, and brooder stove operation have been conducted during the
past year at the West Central Florida Experiment Station, Brooksville,
in cooperation with the Animal Husbandry Division, Bureau of Animal
Industry, USDA. The work of these projects is summarized under the
report of that station.
The new poultry laboratory building, completed in the fall of 1936,
has six rooms on the first floor and two rooms on the second floor which
are used as offices, research laboratories and classrooms. The poultry
buildings have been moved to the new location, comprising 15 acres of
land. During the spring of 1937 two brooder houses and seven range
shelters were constructed for the growing birds. Technical work includ-
ing incubation, feeding trials and flock management are being conducted.

DAIRY PRODUCTS
Following the completion of the dairy products laboratory it is expected
that facilities necessary for research with dairy products will be avail-
able. A study of methods of storing sweet cream and skimmilk solids
during summer for use in ice cream during fall and winter is one of the
research projects contemplated. Others include studies of the effects of
various feeds peculiar to Florida on the flavor of milk and milk products,
the use of some Florida products as flavoring for ice cream, and the rela-
tion of the feeding of dried citrus pulp to the citric acid content and
manufacturing qualities of milk.
Chemical and bacteriological analyses have been made of milk and
ice cream samples brought or sent to the University by various milk
producers, dairy products manufacturers and state employees.

DEFICIENCIES IN FEEDS USED IN CATTLE RATIONS
Purnell Project 133 R. B. Becker, W. M. Neal, P. T. Dix Arnold
and L. L. Rusoff
Investigations in this field are divided into several studies of nutritional
conditions which sometimes are separate, and at other times overlap one
another. These include "salt sick", stiffs or sweeny, calcium deficiency,
"paces" and a rickets-like condition.
I. "Salt Sick": The investigation of nutritional anemia is divided into
several phases, a part of which is conducted in cooperation with other
departments.
A. Copper Analysis of Wire-Grass: The spectrographic method for
estimation of copper in biological materials, developed cooperatively with
the Spectrographic Laboratory, was used in analysis of grass samples
collected for this purpose in conjunction with soil samples on "salt sick"
and healthy areas in 1931. The samples showed an average of about five
parts of copper (Cu) per million in the dry matter of the grasses. The
variations noted in copper content were not sufficient to be considered
statistically significant between the two classes of areas in most instances.







Florida Agricultural Experiment Station


Qualitative estimations were made of 24 other trace elements. Results of
these analyses, in manuscript form, have been submitted to the Journal
of Agricultural Research.
B. Copper Toxicity: Since copper sulfate is a constituent of the "salb
sick" mineral supplement, it was desirable to find the upper limits of
tolerance of cattle for this element, by feeding it in excessively large
amounts. One calf on a ration of alfalfa hay, shelled corn and skimmilk,
received an allowance of 2.0 milligrams of copper (as copper sulfate) per
pound live weight daily when two months of age. He died on the 43rd
day, from copper toxicity. Another calf on similar feed, received 1.5
milligrams of copper daily per pound of live weight since three months
of age. He is now 17 months of age, weighs over 700 pounds, and shows
no external evidence of toxicosis. It would appear from these results that
there is little probability of cattle taking sufficient copper in the regular
"salt sick" mineral to give deleterious effects.
C. Cobalt Deficiency: 1. Controlled Feeding Trials.-Natal grass hay
and shelled corn used in the controlled feeding trials were grown on Norfolk
soils. With these feeds and skimmilk as sources of needed protein, ferric
ammonium citrate and copper sulfate were demonstrated to have an adverse
effect on growth. An Angus-Jersey crossbred heifer which had ceased
to grow while receiving the above feeds and supplements, resumed growth
when given 5.0 milligrams of cobalt (Co) as cobaltous sulfate daily at
13 months of age. She was bred, and dropped a normal heifer calf at
two years of age.
One Jersey bull was grown to a weight of 740 pounds when given 5.0
milligrams of cobalt as a supplement to the hay-corn-skimmilk basal
ration. His heart, liver and spleen were normal when a histological ex-
amination was made. Another animal has attained a weight of over 500
pounds, and showed an additional response to 10 milligrams of cobalt,
as compared with five milligrams.
Spectrographic analyses of the ash of the Natal grass hay, shelled
corn and skimmilk powder used in the controlled feeding trials did not
show the presence of cobalt, even upon extended exposure of the plates.
Results of this work were presented before the American Dairy Science
Association on June 23, 1937, and a manuscript has been submitted to the
Journal of Dairy Science.
2. Field Survey.-Reports were received from areas on certain soil
types that the recommended supplement of salt-iron oxide-copper sulfate
was ineffective in the correction and prevention of a condition locally
called "hill sick". In some respects this bears much resemblance to "salt
sick" in that the animal lacks thrift, growth is retarded, yet the animal
may or may not be anemic as measured by hemoglobin concentration in
the blood. In view of the success with cobalt in the controlled feeding
trials, this element was supplied for use cooperatively with certain herds
under observation. Cattle affected with this condition have responded to
its use in most instances. It appears likely that there may be secondary
effects of the condition in some animals to the extent that they do not
respond to cobalt even though its deficiency may have been the primary
cause of malnutrition.
II. Calcium: The intake of mineral supplement by cows and heifers
in the dairy herd is being recorded continually. The current records deal
with cows during the double-reversal feeding trials each winter, and with
young stock during growth and gestation. A definite seasonal trend in
the intake of bonemeal and "salt sick" mineral was noted with heifers







Annual Report, 1937


on pasture, the rate of consumption increasing during the fall and winter
months.
III. Phosphorus: Bone samples were collected for analysis from a
young cow with a broken lumbar vertebra on range where extreme bone
fragility occurs. Animals from this range have responded to a change of
grazing to a field previously fertilized with phosphorus, but those remain-
ing on the range have not been given access to a continual source of
bonemeal because of relative inaccessibility of parts of the range. Broken
bones occur frequently while cattle are being handled on this range.
IV. A Rickets-Like Condition: The study of a bone fragility of calves
on a muck soil area was extended to a cooperative study with the Spectro-
graphic Laboratory, of forages, water and animal tissues from the area.
Two calves are being raised on a sole ration of Dallis grass hay from this
area in an attempt to produce the condition under controlled feeding. This
malnutrition appears to be caused by some unbalance in the mineral
nutrients.

RELATION OF CONFORMATION AND ANATOMY OF THE DAIRY
COW TO HER MILK AND BUTTERFAT PRODUCTION
State Project 140 R. B. Becker, W. M. Neal, P. T. Dix Arnold
and L. L. Rusoff
This project, cooperative with the Bureau of Dairy Industry, USDA,
has been continued. Three cows were slaughtered and measured during
the year and provided seven lactation and 10 calving records. Records
and preserved organs of one freemartin heifer were contributed to the
study. This station now ranks fifth among the cooperators in numbers
of records contributed to the project.

A STUDY OF THE FEEDING VALUE OF CROTALARIAS
State Project 175 R. B. Becker, W. M. Neal
and P. T. Dix Arnold
Chemical analyses have been completed of all feed samples connected
with the investigation of the feeding value of Crotalaria intermedia. A
manuscript covering this work is in preparation jointly with the Agronomy
Department and the Office of Forage Crops and Diseases, USDA, co-
operators in this project.

A STUDY OF THE ENSILABILITY OF FLORIDA FORAGE CROPS
State Project 213 W. M. Neal, R. B. Becker
and P. T. Dix Arnold
The study of forage crops as silages included corn, Napier grass and
sorghum ensiled in monolithic concrete silos, and sorghum at four stages
of maturity in the one-ton concrete pit silos during the past year. En-
siling losses of the sorghum in the small silos decreased as the crop ap-
proached maturity. Palatability of the sorghum silages was tested with
dairy heifers, which at first showed a preference for the more mature
sorghum. Toward the close of the trial, their preference changed gradually
to the forage in the earlier stages of maturity. The differences in relative
palatability were not great in any instance, nor were any of the silages
refused by the cattle.






Florida Agricultural Experiment Station


BEEF CATTLE BREEDING INVESTIGATIONS
State Project 215 A. L. Shealy, W. W. Henley
and W. G. Kirk
It was deemed advisable to reduce each of the four herds of cows used
in these investigations to 24, since many of the original animals had
passed their period of usefulness. There were a sufficient number of grade
heifers of breeding age from each of the herds to replace those native
cows that were removed. The four herds are headed by purebred bulls
as follows: Lot 1, Hereford; Lot 2, Devon; Lot 3, Brahman; and Lot 4,
Red Polled.
All the native cows were graded as breeding animals at the beginning
of the experiment. The grade heifers as they reach two and three years
of age are graded on the same basis as the cows. By this method it is
possible to determine rather definitely the degree of improvement made
by the use of purebred bulls.
On June 17-18, 1937, the first-cross two and three-year old heifers were
graded. The grades of the native cows, two and three-year old heifers
from each of the four herds are given below:
Av. grade of Av. grade of Av. grade of
Lot No. native cows 3-year old heifers 2-year old heifers
1 Herefords ................ 61.01 71.52 73.02
2 Devons ...................... 60.38 74.85 72.87
3 Brahmas .................. 62.44 73.60 70.85
4 Red Polls .............. 60.75 71.15 64.45
It is readily apparent that considerable improvement has been made
by the use of purebred bulls.
All calves are graded as vealers or slaughter calves. All animals are
weighed every 90 days.
From the weights recorded for several years, it was observed that the
range cows lost considerable weight during the winter months. In an
effort to reduce this loss, half of the native cows in each lot were fed
a limited amount of cottonseed cake, while the other half obtained all of
their feed from the range, and served as a check lot. The cows which
were fed cottonseed cake received an average of 1.3 pounds daily per
head on range for 98 days. The work on winter feeding will be continued
and results given in subsequent reports.
This project is being conducted at Penney Farms in cooperation with
Foremost Properties, Inc., and the Bureau of Animal Industry, USDA.

COOPERATIVE FIELD STUDIES WITH BEEF AND
DUAL-PURPOSE CATTLE
State Project 216 A. L. Shealy, W. W. Henley
and R. M. Crown
This work is conducted cooperatively with 20 cattlemen in 15 counties
extending from Jackson in the west to Lee County in the south. These
studies are being made in many sections so that information concerning
types of ranges, breeding, feeding and herd management practices may
be obtained from several areas in Florida. Native cows are used as founda-
tion breeding stock in all instances; however, many first-cross females of
breeding age are to be found in several herds. Bulls used are purebred
Aberdeen-Angus, Devon, Red Polled and Shorthorn. The following records
are obtained: percent of calf crop on each range; age, sex and grade of
offspring; type of range; number of acres allowed per animal; breeding







Annual Report, 1937 57

seasons each year; disposal of bull calves; age and time of marketing
male offspring; and other important points regarding herd management.
All calves are graded each year according to the official schedule as
used by the United States Department of Agriculture for grading vealers
and slaughter calves. In June 1937 the calves in the experimental herds
graded as follows: Good, 10 percent; medium to good, 31 percent; medium,
52 percent; and common, 7 percent.

BEEF AND DUAL-PURPOSE CATTLE INVESTIGATIONS
State Project 219 A. L. Shealy, W. W. Henley
and W. G. Kirk
Breeds of cattle used are as follows: Herefords at the Main Station;
Aberdeen-Angus at the North Florida Station; Devon at the Everglades
Station; and Red Polled at the West Central Florida Station. Native
cows at each station are bred to purebred bulls of the breeds kept at the
respective stations. Grade offspring are thus obtained for experimental
studies. All animals are weighed every 28 days; birth weights and growth
rates on all calves are recorded.
The native cows have been graded as mature breeding animals. All
grade heifers, as they reach two and three years of age, are similarly
graded. All calves are graded as vealer or slaughter calves. The heifer
calves are retained for breeding purposes, while the bull calves are castrated
and used in feeding trials.
Milk production records are obtained with the purebred Red Polled
cows at the West Central Florida Station.
This project is in cooperation with the Bureau of Animal Industry,
USDA.

INVESTIGATIONS OF HEMORRHAGIC SEPTICEMIA IN
CATTLE AND SWINE
Purnell Project 236 D. A. Sanders
During the past year a study was begun on enzootic bronchopneumonia
of calves. This condition as observed is responsible for a heavy mortality
rate and stunted condition among the young calves in affected herds.
Pasteurella boviseptica was the predominating bacterial species encountered
upon microscopic and cultural examination of diseased lung tissue. The
virulence of these organisms for small laboratory animals was typical
of the pasteurella group. A fungus, Penecilium sp., has been isolated from
the consolidated portions of diseased lung tissue in some animals examined.
The disease usually was ushered in by symptoms of acute diarrhea
(white scours), followed by cough, swelling of the sublingual region,
drooling, nasal discharge, difficult breathing, bloody droppings and death
or lingering illness. A virulent colon type organism was recovered from
the intestinal canal and droppings of affected calves in the early stage
of infection. Oral administration of the colon type organism caused grave
intestinal disturbances in calves similar to the early symptoms observed
in naturally occurring cases.
Attempts were made to transmit the disease by contact. Calves in
various stages of the condition were selected from naturally occurring
field cases and confined with healthy calves in insect-proof isolation pens.
Diarrhea typical of early stages of the disease developed in calves thus
exposed; however, the typical bronchopneumonia did not follow in these
cases. Nasal and bronchial secretions of animals suffering from enzootic
bronchopneumonia, minced portions of affected lung tissue and bacteria-







58 Florida Agricultural Experiment Station

free filtrates of these materials did not reproduce the disease when healthy
calves were exposed by nasal and oral routes. Microscopic examinations
of fecal samples of young affected calves showed various species of coccidia
and nematode ova. Similar examinations of feces of older calves suffering
from a chronic form of enzootic bronchopneumonia revealed heavy nematode
infestations. Postmortem examinations of yearling calves surviving the
acute attack showed presence of the cattle hookworm, Bunostomum phle-
botomum, the cattle nodular worm, Oesophagostomum radiatum, small tri-
chostrongyles, Cooperia sp., and the cattle lungworm, Dictocalus viviparus.
On the basis of observations made thus far it seems that these pre-
disposing factors instigate conditions favorable for the development of
the symptomatic complex of enzootic bronchopneumonia in young dairy
calves.
Studies were made of some factors regarded as influencing susceptibility
of swine to P. suiseptica infection (swine plague). Test pigs were given
the simultaneous serum-virus treatment for hog cholera. One-half of
these test pigs received in addition anti-swine plague aggression. Immed-
iately following vaccination all pigs received intra-nasal inoculations of
Pasteurella isolated from the heart blood of swine which died several weeks
following vaccination. The test pigs were allowed to consume the skinned
carcass of rabbits which died 18 hours following nasal inoculation of the
same culture. No unfavorable sequelae developed as a result of such
exposure.
THE DIGESTIBLE COEFFICIENTS AND FEEDING VALUE OF DRIED
GRAPEFRUIT REFUSE AND DRIED ORANGE REFUSE
Purnell Project 239 W. M. Neal, R. B. Becker, P. T. Dix Arnold
and L. L. Rusoff
In previous reports the dried peel, rag and seed from citrus canneries
have been referred to as dried grapefruit (or orange) cannery refuse.
After conference with various manufacturers it was agreed to use the
term "citrus pulp" to describe such products. The term "citrus meal" is
used when the dried product has been ground to a meal.
Biological Feeding Trials: Two Jersey steers attained weights of 700
and 800 pounds at 18 and 20 months of age on the ration of four parts
dried grapefruit pulp and one part of cottonseed meal (41% protein) with
an allowance of two-thirds ounce of cod liver oil daily. The heavier animal
was normal when slaughtered. The beef of this Jersey was of excellent
quality and the fat was white, indicating scarcity of the carotin pigment
in the feeds.
Another animal, previously fed sorghum silage, dried grapefruit pulp
and cottonseed meal, was placed on the pulp and meal alone. His appetite
failed, and some symptoms of vitamin A deficiency were evident, although
the case did not progress to a typical advanced stage. When cod liver oil
supplement was added, he responded slowly with increased growth.
Vitamin A Assay: The vitamin A content of dried grapefruit pulp is
being assayed with piebald rats, using the U.S.P. XI technique. Preliminary
trials show the vitamin A content to be low in relation to that of forages.
Double-Reversal Feeding Trial: A 90-day double reversal feeding trial
was conducted with eight Jersey cows, comparing the relative value of dried
grapefruit pulp with dried beet pulp, which is the nearest similar known
feed. These two feeds provided 40 percent of the intake of required total
digestible nutrients. No untoward effects were noted from this level of
intakes. A limited allowance of corn silage, No. 1 Federal graded alfalfa
hay and mixed concentrates made up the basal ration throughout the







Annual Report, 1937


trial. Two additional trials are required to provide sufficient data from
which to make definite comparisons of these two feeds.
Steer Feeding: Feeding trials with steers have been conducted at the
Citrus Experiment Station, Lake Alfred, to determine whether the fresh
material direct from the cannery is as valuable for feeding purposes as
the dried grapefruit pulp. The fresh material is less palatable than the
dried.
Processing Citrus Cannery Waste: The process of freeing the bound
water and pressing the treated waste prior to drying the product developed
at this station has been used during the past year in the production of
several thousand tons of dried grapefruit pulp by commercial plants.

THE EFFICIENCY OF THE TRENCH SILO FOR PRESERVATION OF
FORAGE CROPS AS MEASURED BY CHEMICAL MEANS AND
BY THE UTILIZATION OF THE NUTRIENTS OF THE SILAGE
BY CATTLE
State Project 241 A. L. Shealy, W. M. Neal
and R. B. Becker
The study of ensiling changes in the trench silo was limited to chemi-
cal analyses of samples on hand. The data are being tabulated, analyzed
and prepared for publication which will complete this phase of the project.
The steer feeding phase was temporarily discontinued during the fiscal
year 1936-37. However, steers are available and the silos are being filled
with the various silage crops for use in the feeding period 1937-38.

A COMPARATIVE STUDY OF CORN AND LIQUID MILK VERSUS A
GRAIN AND MASH RATION IN FEEDING FOR EGG PRODUCTION
State Project 244 N. R. Mehrhof and E. F. Stanton
This project was inactive during the year 1936-37 because of insufficient
housing facilities, but will be continued at a later date.

A COMPARATIVE STUDY OF THE VALUE OF MEAT SCRAPS, FISH
MEAL, AND MILK SOLIDS AS SOURCES OF PROTEIN
FOR EGG PRODUCTION
State Project 245 N. R. Mehrhof and E. F. Stanton
This project was inactive during the year 1936-37 because of insufficient
housing facilities, but will be continued at a later date.

LIGHTS VERSUS NO LIGHTS FOR EGG PRODUCTION ON SINGLE
COMB WHITE LEGHORN PULLETS AND HENS
State Project 246 N. R. Mehrhof and E. F. Stanton
This project was inactive during the year 1936-37 because of insufficient
housing facilities, but will be continued at a later date.

THE ETIOLOGY OF FOWL PARALYSIS, LEUKEMIA AND ALLIED
CONDITIONS IN ANIMALS
State Project 251 M. W. Emmel
The intravenous injection of Salmonella aertrycke into parasite-free
birds and the oral exposure of birds naturally and artificially infested with
the various species of coccidia, Eimeria praecox, E. necatrix, and E. maxima







Florida Agricultural Experiment Station


as well as Ascaridia, Taenia and Capillaria resulted in the development
-of a high percentage of cases of fowl paralysis, "light", anemia, lympho-
matosis and leukemia. Hemocytoblastosis occurs shortly after infection
and is a fundamental process in the development of many of the pathologic
manifestations. Hemocytoblastosis results from infection by bacteria of
the paratyphoid and typhoid groups, the "transmission agent" of leu-
kemia in the fowl, certain chemicals and other substances. It also oc-
curs in tick paralysis, nutritional anemia, avitaminosis A and a number
of other conditions under study. S. enteritidis, S. schottmiilleri, S. typhi-
murium and S. psittacosis can also induce fowl paralysis. Strains of
S. aertrycke isolated by other investigators from the turkey, pigeon and
human do not differ materially from chicken strains of the same micro-
organism in their ability to induce this group of diseases.
Leukemia has been experimentally induced in the monkey, dog, hog,
sheep and mouse. The nature of this disease in these animals is similar
to that in the chicken.

A STUDY OF PLANTS POISONOUS TO LIVESTOCK IN FLORIDA
Purnell Project 258 D. A. Sanders, M. W. Emmel
and Erdman West
During the past year field observations have been made on livestock
poisoned by cocklebur, Xanthium sp.; oleander, Nerium oleander; oak
forage, Quercus sp.; braken, Pteris caudata; and Crotalaria spectabilis.
The conditions under which poisoning occurred were usually accidental
or where there was a scarcity of other forage. Experimental feedings
of oleander show this shrub to be exceedingly toxic. From 5 to 30 grams
of dried or green leaves are fatal for cattle. Postmortem examination
showed a severe muco-enteritis or in cases where the animal survived
beyond this stage there occurred gastro-intestinal hemorrhage. An ex-
clusive ration of oak forage produced severe constipation followed by
intestinal hemorrhage in cattle. Yearlings receiving a ration of the com-
mon braken developed clinical manifestations of membranous enteritis and
intestinal hemorrhage similar to that observed in field cases. Pigs fed
on the young cotyledon stage of cocklebur and C. spectabilis developed
symptoms of poisoning and exhibited lesions similar to those observed
in animals having access to these plants.
A large number of seeds have been added to the seed collection in the
Herbarium, including most of the known poisonous seeds of Florida plants.

STUDIES IN FLEECE AND MUTTON PRODUCTION
State Project 274 C. H. Willoughby and A. L. Shealy
Work on this project was begun July 1, 1936, with the flock of sheep
maintained by the instructional division of the College of Agriculture.
This flock consists of 17 ewes over two years old, three yearling ewes and
one registered Hampshire ram. Five of the ewes are natives from ranges
in western Florida, 12 are high grade Hampshires and three have a small
amount of Dorset blood mixed with Hampshire. In January, 13 lambs
were dropped, seven males and six females, the average birth weight being
7 pounds. The females are retained as breeding stock, while the males
are castrated and used in mutton studies. On April 26, scores were taken
on wool production. Records are kept on the length and fineness of wool
fiber; the character, density, condition, and color of fleece. The adult
sheep yielded an average of 5.63 pounds of wool per ewe, the lambs 1.6
pounds.






Annual Report, 1937


A STATISTICAL STUDY OF THE RELATIONSHIP BETWEEN TEM-
PERATURE AND EGG WEIGHT (SIZE), BODY WEIGHT AND
EGG WEIGHT, BODY WEIGHT AND PRODUCTION, AGE AND
EGG WEIGHT OF SINGLE COMB WHITE LEGHORN PULLETS
State Project 307 0. W. Anderson, Jr., and N. R. Mehrhof
Records from the Florida National Egg-Laying Contest (1931-1934)
at Chipley are being used as a basis for this study. These records, on
Single Comb White Leghorn pullets that completed their first year's pro-
duction, have been tabulated and the statistical analyses of these data
will be made to determine the degree of correlation between the factors
listed above.

UTILIZATION OF CITRUS BY-PRODUCTS FOR POULTRY
State Project 308 N. R. Mehrhof and L. L. Rusoff
In a study of the utilization of citrus by-products for poultry, five
lots of Single Comb White Leghorn chicks of the same breeding were
placed in a battery brooder and all management factors were kept uniform.
Citrus meal was used to replace cornmeal in the check ration to the extent
of 0, 5, 10, 15 and 20 percent of the total ration. All chicks were weighed
individually at weekly intervals. Feed consumption data were recorded
each week. Mortality and data on condition of chicks were tabulated.
The pullets are being raised to maturity and will be carried through the
laying year. The investigation was repeated, using five lots of Single
Comb White Leghorn cockerels. Feed and management conditions were
the same as with the chicks.
Trials also were made with Single Comb White Leghorn chicks using
lemon pectin and naringin (a glucoside) in the check ration to determine
their effects on growth.
POULTRY BREEDING
State Project 309 N. R. Mehrhof
This project was started in the spring of 1936 with pedigreed eggs using
new strains of Single Comb White Leghorns and Single Comb Rhode Island
Reds. Work also is being continued with the strains of Single Comb
Rhode Island Reds, Single Comb White Leghorns, and Barred Plymouth
Rocks originally in the College of Agriculture flock.
Factors under consideration are egg production, egg size, longevity,
livability of chicks, hatchability, broodiness and disease resistance.
In addition to these studies, breeding flocks are maintained to supply
eggs and chicks for further experimental work.

DEFICIENCIES OF PEANUTS WHEN USED AS A FEED FOR SWINE
State Project 310 W. G. Kirk
Most pigs raised in Florida are fattened on peanuts, which are deficient
in certain mineral elements necessary for growth and the development of
strong bones.
Sixteen 1936 spring farrowed pigs weighing an average of 59 pounds
were divided into four lots of four pigs each. At the end of the 140-day
period, each of the four lots was divided into two groups of two pigs each.
One pair from each lot was fed the original ration, while the second was
fed in addition two grams of common salt per pig per day. The follow-
ing table gives the rations fed, average daily gains and amount of peanuts
required per pound of gain for both the 140 and 48-day periods.






Florida Agricultural Experiment Station


TABLE 7.-GAINS MADE AND PEANUTS REQUIRED PER POUND OF GAIN BY
PIGS ON VARIOUS RATIONS OF PEANUTS WITH AND WITHOUT SALT.

1st period, 140 days 2nd period, 48 days
Av. ) Peanuts Peanuts
Lot Rations daily I required Av. daily required
gain per gain per
per pound per pig pound
Spig I of gain of gain

1 Peanuts alone 0.37 4.05 No salt group 0.22 4.99
Salt group 0.94 2.13

2 Peanuts, 98 parts 0.34 4.39 No salt group -0.01 ......
Calcium carbonate, Salt group 1.05 2.04
2 parts
3 Peanuts, 99 parts 0.42 3.72 No salt group 0.04 28.24
Cod liver oil, 1 part Salt group 1.04 2.00
4 Peanuts, 97 parts 0.36 4.36 No salt group 0.11 11.00
Calcium carbonate, Salt group 1.02 2.14
2 parts
Cod liver oil, 1 part

The bones of the pigs in Lot 1 and Lot 3 were soft, weak and thin-
walled, while those of the pigs in Lot 2 and Lot 4 were harder, stronger
and thicker walled.
METHOD OF HANDLING SOWS AND YOUNG PIGS
State Project 311 R. M. Crown
Since climatic conditions of Florida are such that swine can graze
in fields during the entire year, and since many crops adapted for this
purpose may be raised, it is deemed important to determine the value of
such crops in furnishing feeds for swine.
Studies are being made to determine the practicability of maintaining
the breeding herd of swine on field crops, allowing the brood sows and
pigs to gather as much of their feed from fields as possible, thereby using
a minimum amount of purchased feeds.
THE UTILIZATION OF CITRUS MEAL AS SWINE FEED
State Project 318 R. M. Crown, W. G. Kirk
and W. M. Neal
Within recent years the drying of citrus cannery by-products has been
established on a commercial basis, and further development can be ex-
pected in the industry. One of the products, grapefruit meal, is high in
carbohydrates, and has been shown to be an excellent feed for cattle and
one having a conditioning quality.
Work with single pigs fed citrus meal at 30, 60 and 85 percent levels
showed successive increments of meal to make the ration less desirable.
One possibility is that the pectin content of the meal contributed bulk
to the ration to the extent of limiting feed intake.
Preliminary trials are being conducted in which corn is being replaced
by grapefruit meal at 0, 5, 10 and 20 percent levels in the standard ration
of 90 parts of corn and 10 of fishmeal using weanling pigs fed individually.
A mineral mixture consisting of bonemeal 50 parts, marble dust 50, salt
25, red oxide of iron 25, and pulverized copper sulfate 1 part is self-fed.







Annual Report, 1937


CHEMISTRY AND SOILS

Substantial progress has been made in the solution of certain fertility
problems, notably those of the Sanford and other areas where the so-called
minor elements appear to become increasingly important. Particular at-
tention in this has been given to the iron component especially for its
intimate relation to the general problem of anemia.
Under the authorization of the Commissioner of Agriculture cooperative
relations were set up during the year between the University of Florida
and the Soil Survey Division of the Bureau of Chemistry and Soils for
detailed soil survey work in Alachua County, Florida, in cooperation with
the County Commissioners. As a result a party of three sent down by
the Bureau under the leadership of Mr. A. E. Taylor completed the field
work on about one-third of the county during the winter.
Late in the year the department was completely reorganized with the
view of fully coordinating the work in this field in all three divisions of
the University-teaching, research and extension. Dr. VV. Allison,
formerly in charge of the Everglades Experiment Station, and more
recently Chief of the Division of Soil and Water Conservation Investiga-
tions of the Soil Conservation Service in the U. S. Department of Agri-
culture, returned to Florida to become head of this newly established
department.

DETERMINATION OF THE EFFECT OF VARIOUS POTASH
CARRIERS ON THE GROWTH, YIELD AND
COMPOSITION OF CROPS
Hatch Project 37 R. W. Ruprecht, Citrus Station
The experiment at the Citrus Station was continued and a good crop
of fruit was harvested. The tangerines receiving the low grade sulfate
of potash-magnesia gave the highest yield, with the muriate of potash
plot second. The Hamlin oranges likewise had the highest yield with the
low grade potash-magnesia salt with almost as good a yield on the plot
receiving muriate of potash once a year and high grade sulfate of potash
twice a year. The muriate of potash plot had the lowest yield.
With Marsh Seedless grapefruit there was very little difference in
yield among the first three plots, no one source of potash proving superior.

THE EFFECT OF VARIOUS FERTILIZER FORMULAS
State Project 94 R. W. Ruprecht, Citrus Station
In the source of nitrogen plots at the Citrus Station the crop was too
light to draw any conclusions. Further analyses of soil and foliage from
these plots showed that the soil in the plots receiving bone meal had a
higher replaceable calcium and phosphoric acid content than the soils from
the superphosphate plots. However, even the superphosphate plots had
a higher replaceable calcium content than the virgin soil. Foliage analyses
showed that the inorganic sources of nitrogen produced a higher nitrate
and total nitrogen content in the sap early in the season and maintained
this content until fall. Organic sources or mixed organic and inorganic
sources produced leaves having a fairly low nitrate and total nitrogen
content early in the season, increasing to a maximum in mid-summer.
A better quality of fruit is produced under these conditions.
The experiments at Avon Park and Homestead were continued. The
fruit record was obtained for the oranges at Avon Park but these showed







Florida Agricultural Experiment Station


no differences due to fertilizer treatment. All the trees were in good
condition at the close of the year.
Potatoes.-A fair yield of high quality potatoes was harvested from
the plots at Hastings. In the source of nitrogen test Cal-nitro again
produced the highest yields. Cyanamid was distinctly inferior. Reducing
the phosphoric acid content in the fertilizer to 2% has had no marked
effect on the yield. Slightly higher yields were obtained where a ton
of 5-7-5 fertilizer applied previous to planting was supplemented with
a top-dressing of 500 pounds of 5-7-5. Increasing the potash to 10% in
the formula had no effect on the yield nor did increasing the nitrogen to
6% bring about any decided increase in yield over 4%. None of the rare
elements added had any measurable influence on the growth or yield.
DETERMINATION OF THE EFFECT OF GREEN MANURES ON THE
COMPOSITION OF THE SOIL
Adams Project 96 R. M. Barnette
Phytometer studies on the comparative rate of decomposition of Cro-
talaria striata, C. spectabilis and C. intermedia have been continued.
Partial chemical analyses of the samples of the original cover crop materials
and of the residues screened from the surface soil after approximately one
year of decomposition in Norfolk fine sand have been completed. The
following percentages of constituents of the crotalarias have been liberated
during the course of the decomposition:
Carbon Nitrogen Phos. acid Potash Lime
percent percent percent percent percent
Crotalaria striata ............ 88 89 89 99 80
Crotalaria spectabilis ...... 95 94 93 99 93
Crotalaria intermedia .... 89 87 81 98 89
It is evident that C. spectabilis decomposes at a more rapid rate than
C. striata or C. intermedia. C. spectabilis produced the largest yield of
oats during the 1934-35 season, C. striata produced the second largest yield
while C. intermedia did not increase the yield over that obtained from
soils without additions of cover crop materials. During the 1935-36 season
oats followed by Sudan grass were planted in the soil of the phytometers
from which the residues had been screened without the further addition
of cover crop materials. The yields of these plants were not increased
in the phytometers in which the crotalarias had been previously incor-
porated with the surface soil, indicating no residual effect of these plant
materials on the content of well decomposed organic matter in the soil.
Chemical analyses of soil samples collected from the plots of the
cover crop experiment at Lake Alfred in 1925 (virgin Norfolk sand)
1929, 1932 and 1936 have been partially completed. An annual leguminous
or non-leguminous summer cover crop has maintained approximately the
original organic matter, nitrogen and carbon content of the surface 0-8
inches of soil. The 8-16 and 16-24 inch depths have not been affected by
the cover cropping systems and no significant differences were noted in
effect of the different summer covers. Clean culture has definitely and
progressively decreased the organic matter, nitrogen and carbon contents
of all soil depths since 1925.
A laboratory study of the relative rate of decomposition of 14 summer
cover crops in the surface soil of a Norfolk fine sand has been started.
The summer cover crops used in this study are: velvet beans, C. intermedia,
C. spectabilis, C. striata, Natal grass, Indigofera, Para grass, cowpeas,
sesbania, Spanish needles, mixed grove cover, crabgrass, beggarweed and
corn stalks.







Annual Report, 1937 65

A STUDY OF CHLOROSISS" IN CORN PLANTS AND
OTHER FIELD CROP PLANTS
Adams Project 220 R. M. Barnette
Yields of corn were obtained from a cooperative field experiment with
the Agronomy Department to determine the residual effect of the applica-
tion of zinc sulfate under corn for the prevention of whitebud. The
initial zinc sulfate treatments were made in the spring of 1935 to a field
on the Station farm which uniformly grew severely affected whitebud
corn plants. Very satisfactory increases in corn yields were obtained
from the 12-pound and 36-pound per acre rates of application of zinc
sulfate in 1935. Half the plots treated in 1935 were retreated with 12
pounds per acre of zinc sulfate in 1936 and half were not retreated. The
corn rows were placed as nearly as possible in the same location in the
field for both years of the experiment.

TABLE 8.-CORN YIELDS INDICATING THE RESIDUAL EFFECT OF THE
APPLICATION OF ZINC SULFATE TO THE SOIL.
Corn Corn
Application of zinc sulfateI yield Application of 89% zinc sul. yields*
1935 1936 I bu/A 1935 ] 1936 bu/acre

None None 9.5 None None 9.5
12 lbs. per A None 20.2 12 lbs. per A 12 lbs. per A 21.7
36 lbs. per A None 22.5 36 lbs. per A 12 lbs. per A 23.2
*Average of 10 plots in randomized Latin squares.

The zinc sulfate applied in 1935 was as effective in increasing corn
yields in 1936 as the additional application of 12 pounds per acre in 1936.
This experiment is being continued this year. In addition, an experiment
has been started to study further the residual effect of both row and
broadcast applications of zinc sulfate.
Corn yields for the 1936 season from the source of zinc test conducted
on a field on the Station Farm uniformly affected with whitebud are given
in Table 9.
TABLE 9.-YIELDS OF CORN IN BUSHELS PER ACRE FROM SOURCE OF ZINC
EXPERIMENT.

Equivalent pounds per acre of zinc
applied in row before planting
Source of zinc
None 0.72 I 1.80 1 3.60 | 7.20 1 14.40
.bu/A I bu/A ] bu/A I bu/A I bu/A I bu/A

Zinc sulfate (36% Zn) .......................... 8.97 14.31 18.01 18.43 20.15
Zinc ammonium chloride (11.0% Zn) 17.28 23.03
Zinc nitrate (21.9% Zn) ........................ 15.16 18.85
Zinc oxide (80.3% Zn) ........................ 15.55 18.07
Zinc ore No. 1 sulphidee) (58.0% Zn) 9.32 9.05 9.32
Zinc ore No. 2 (mixture) (25.0% Zn) 16.18 16.31 18.81
Zinc powder (metal) (100.0% Zn) .... 13.76 18.83
Vasco seed treatment .......................... 10.86
Zinc sulfate seed treatment ................ 14.23







Florida Agricultural Experiment Station


Yields given in Table 9 are the average of 20 replications of each
treatment in randomized blocks of plots in the field. The corn yields
emphasize the superiority of the soluble zinc compounds such as zinc
sulfate, zinc ammonium chloride and zinc nitrate over the zinc oxide,
sulphide and metallic zinc in preventing the development of whitebud of
corn and increasing corn yields. Zinc ore No. 1, which is a sulphide, was
very ineffective in preventing whitebud of corn while Ore No. 2, which
contained some zinc sulfate, was more effective than the insoluble sul-
phide but less effective than the purer, more soluble compounds of zinc.
The Vasco and zinc sulfate seed treatments were made by sticking
these materials on the seed corn with a molasses-water mixture after
washing the seed with soapy water. The quantities adhering to the seed
were very small. Three seeds were planted in each hill. The zinc sulfate
seed treatment was more effective in increasing corn yields than the
Vasco treatment. Vasco is a mixture of the oxide, hydroxide and sulphide
of zinc. Additional experiments on the various sources of zinc were not
undertaken this season.

BRONZING OR COPPER LEAF OF CITRUS
State Project 223 C. E. Bell and R. W. Ruprecht
Continued applications of limestone have caused a slight decrease of
soil acidity. Even the largest application, a total of 135 pounds of lime-
stone per tree over a period of four years, has produced a change of
only .39 pH.
There has been an increase of replaceable calcium and magnesium but
significant increases are found only where these treatments were added
to the soil. Replaceable potassium apparently has been increased only
in the sub-soil. The trees continue in a good physical condition and no
signs of "bronzing" have been observed on any of the plots since it dis-
appeared early in the experiment.

THE OCCURRENCE AND BEHAVIOR OF LESS
ABUNDANT ELEMENTS IN SOILS
Adams Project 240 0. E. Gall and R. M. Barnette
The study of toxicity of replaceable zinc with an Orangeburg fine sandy
loam and a Greenville clay loam have been continued. Replaceable zinc
was toxic to corn and cowpeas at a concentration of approximately 400
ppm. in the unlimed soils. Calcium carbonate at the rate of 4,000 pounds
per acre increased the limits of toxicity of replaceable zinc to corn to
approximately 650 ppm. and to cowpeas to 700 ppm.
The zinc deficiency in corn known as whitebud was produced experi-
mentally for the first time in three-gallon coffee urn pot cultures of a
fine sand which under field conditions had grown whitebud corn plants for
years. This was accomplished by permitting the cultures which were
kept free from vegetation, to settle and leach with rainwater for a year
previous to planting corn. A range of applications of 89% zinc sulfate
from none to 500 pounds per acre was made to the surface soil of the
cultures. Five crops were grown in the cultures: (1) corn, then (2) cow-
peas, (3) oats, (4) corn and (5) corn. The growth of the plants was
definitely increased with an increase in the rate of application of zinc
sulfate with the exception of the fifth corn crop where toxicity was
observed in the 500 pounds per acre rate cultures. The zinc sulfate ap-
plications completely prevented the development of whitebud symptoms
in the corn plants.







Annual Report, 1937


Chemical analyses of leachings of water following rain storms revealed
that very small concentrations of zinc remained soluble enough to be re-
moved from the nine inches of soil. Through its direct effect upon the
soil, the zinc sulfate increased the leaching of calcium from soil when
it was applied in large quantities. By an indirect effect on plant growth,
and hence the intake of water and plant nutrients, zinc sulfate influenced
the leaching of nitrates, potassium and calcium.
Results of a comparison of a chemical and a spectrographic method
for the determination of zinc in plant ashes were published cooperatively
with the Spectrographic Laboratory. The greatest divergence in results
obtained by the two methods was largely attributable to incomplete ex-
traction of the ash and retention of a small amount of zinc in the sulphide
precipitate in the chemical method.
The zinc content of indigenous weeds and grasses was found to be
more than 41 ppm. of dry matter in comparison with 16 ppm. of planted
cover crops of C. spectabilis and C. intermedia grown at the same time
in adjacent plots.
Spectrographic and chemical analyses of a number of soil samples
collected from virgin and cultivated areas are being made cooperatively
with the Spectrographic Laboratory. Total quantities of the trace elements
including Sr, Ba, V, Cr, Mn, Co, Tn, Ni, Ag, Sn, Cu, Ti, Mo, Pt, B and
Zn have been determined spectrographically, and insoluble matter, organic
matter, N, pH, Fe, Al, P, Ca, Mg and K chemically on approximately
150 samples of soils collected in several counties of the State. Thus far,
results indicate that the well drained sandy soils of the Norfolk and
related series have a high percentage of insoluble matter and low per-
centages of organic matter and acid-soluble plant nutrient elements with
a small variety and percentages of the trace elements. On the other
hand, the more poorly drained soils and especially those derived partially
from limestone have a lower percentage of insoluble matter, higher per-
centages of acid-soluble plant nutrient elements and a greater variety
and higher percentages of the trace elements.
Fertilization has increased the phosphorus content of the soil in all
of the samples and the content of manganese, copper and boron in most
of the samples.
SOIL AND FERTILIZER STUDIES WITH CELERY
State Project 252 E. R. Purvis and R. W. Ruprecht
Celery Laboratory
Comparative Value of Various Fertilizer Materials.-Nitrate of soda,
both Chilean and synthetic, gave better yields of quality celery than any
other source of nitrogen studied. Sulfate of ammonia, both when used
with enough lime to produce a neutral fertilizer and when used without
lime, produced very poor crops. Cyanamid, even though applied previous
to setting the plants, produced a small crop of inferior quality. Nitrate
of potash, low grade, produced a very good crop of high quality celery
second only to the nitrate of soda plots. Due to the increased yields
obtained in previous years with fertilizer containing 6% of phosphoric acid,
the basic formula used this year contained 6% POa. The 3% P20s plots
produced slightly lower yields than the 6% plots.
Liming Materials.-In the comparison of liming materials no one form
was found superior. Applications of 400 pounds and 1,600 pounds of
hydrated lime per acre produced the same change in pH.
Minor Elements.-In pot culture tests with 15 different rare or minor
elements no marked benefits were noted with any one element. However,







68 Florida Agricultural Experiment Station

as was found last year, a combination of manganese, zinc and cobalt pro-
duced greater response than did any of these elements added alone.
Nitrites.-Further studies on the presence of nitrites in the soils has
shown that it is due to the partial oxidation of ammonia rather than to
denitrification of nitrates. The presence of nitrites in the soil was also
shown to be the cause of a disease of soybeans. This disease manifests
itself by a desiccation of the leaves of the plant, the leaves first assuming
a parched green color and then turning brown. The disturbance usually
occurs in the field a few days after a heavy rain, but may be produced
within 12 hours under controlled greenhouse conditions.
There is strong evidence that nitrite toxicity is also responsible for
the blossom-end rot disease of tomatoes, although conclusive proof on
this point is lacking. The wilting of tomato plants on water-logged soils
is induced by the presence of nitrites and may be readily produced under
controlled conditions.
Chlorine.-Greenhouse studies to determine the chlorine tolerance of
celery were conducted and showed no harmful effects until a concentra-
tion of about 800 ppm. of Cl was reached. As it is exceptional to find
soils in the Sanford area containing more than 100 ppm. Cl, it is extremely
doubtful that there is any danger of Cl toxicity developing.

THE INVESTIGATION OF VITAMIN C CONTENT OF
FLORIDA FRUITS AND VEGETABLES
State Project 292 R. B. French
The effect of several factors upon the concentration of vitamin C and
acid in citrus fruits has been investigated. Vitamin C has been determined
by the use of Tillman's indicator and acidity by titration to alkalinity to
phenolphthalein.
Vitamin C and acid have been followed in ripening oranges through
and beyond maturity. These two factors show variation with physiological
age. Acidity and vitamin C decrease at comparable rates to and beyond
maturity in late ripening oranges (Valencia). With early (Parson Brown)
and midseason (Pineapple) oranges, an increase in the vitamin content
at maturity precedes the subsequent decline.
A high concentration of vitamin C in a given variety is associated with
a high quality juice, but a juice of poor quality does not necessarily have
a low concentration.
Analyses of a number of pineapple oranges from different groves have
shown variations in content of vitamin C between 50 and 75 mgm. per
100 cc. of juice. This large variation has not been associated definitely
with any one factor.
Storage tests at 40* F. with oranges and grapefruit have shown that
an increase in concentration of vitamin C up to 30% may occur in the
first two weeks. This increase is not entirely consistent as it is associated
with maintenance of acid level. Thereafter the vitamin content drops
off and the decrease parallels a like one in acidity.

NUTRIENT SALT CONCENTRATION IN THE SOIL WITH
SPECIAL REFERENCE TO THE TRACE ELEMENTS
State Project 293 R. B. French
Studies during the year have shown that corn growing in sand culture
and supplied with chemically pure nutrients has an unusually high iron
requirement, as compared with such other plants as tomatoes, rice, wheat,
etc., at least when the requirement is interpreted as that concentration







Annual Report, 1937


necessary for the prevention of chlorosis. Thus, 100 parts per million
of iron as the citrate or nitrate will not entirely prevent the development
of chlorosis while 25 ppm. ferrous sulfate produced entirely normal plants
from this standpoint. The general response of the plant to ferrous sulfate
was excellent; to ferric citrate, fair, and to ferric nitrate, very poor.
The concentration of iron in the young plant apparently decreases with
increase in dry matter production. The level of iron is highest in the
stunted plants. It seemed to make no difference whether the plants were
suffering from an iron or boron deficiency. A better understanding of the
iron metabolism of plants and of the availability for animal and human
nutrition of the iron which they assimilate is exceedingly important in
the solution of the general problem of anemia.

MINERAL CONTENT OF VEGETABLE CROPS WITH SPECIAL
REFERENCE TO IRON
State Project 294 H. W. Winsor
Analyses for iron, calcium and magnesium have been run on 23 kinds
of vegetables from many points in Florida. The mineral content shows
wide variation according to the areas in which the plants were produced.
In general, the highest iron was found in plants grown on the heavy red
soils and certain of the muck soils; the lowest in those produced on the
light sands.
In soil supplement tests conducted on Leon fine sand, under controlled
conditions at Gainesville, ferrous sulfate, in either the presence or absence
of copper sulfate, failed to give an appreciable increase in the iron content
of collard greens. However, the yield of collards in these plots was in-
creased over 50% by the use of 100 pounds of ferrous sulfate per acre.
The method for colorimetric determination of iron has been further
improved by developing the ferric thiocyanate color in a non-evaporating
organic solvent which is miscible with the sample solution. The color
developed in this new medium is 85% more intense than that developed
in water solution, and 27% more intense than that in the acetone-water
mixture previously employed.

A STUDY OF THE SO-CALLED "QUICK METHODS" FOR
DETERMINING SOIL FERTILITY
State Project 306 C. E. Bell
The work on this project during the year has consisted largely of a
study of the various published methods that have been used for their com-
parative effectiveness in displacing phosphorus, calcium and magnesium
from various soil types which had received known quantities of various
fertilizer materials.
Though the methods are found to vary considerably in the amounts of
phosphorus, calcium and magnesium displaced in the variously treated
soils, this variability was found to be fairly consistent as among different
soils tested. That is to say, while one method may extract more plant
food from a given soil than another, the ratio of action seemed uniform
from soil to soil. Thus among the methods and soils tested for phosphorus,
for instance, results on a given soil were found to vary as much as 1.1
to 42.6 ppm. on a single sample.
The inorganic solutions used are found to displace about 10 times as
much phosphorus as the organic solutions. Tenth normal hydrochloric
acid and normal ammonium chloride seem to displace fairly comparable
amounts of phosphorus, calcium and magnesium from the soil.







Florida Agricultural Experiment Station


ENTOMOLOGY

Perhaps the most important entomological event of the year was the
discovery in Florida of the South American weevil, Naupactus leucoloma
Boh., an insect not heretofore recorded from North America. The larvae
are a severe pest of cotton, corn, peanuts, velvet beans, potatoes and sweet
potatoes, and have been found on apple trees, Mexican clover (Richardia)
and carpet grass. In fact, they seem to be very general feeders. In
many fields in the infested area, which includes about 30 square miles in
northwest Walton and northeast Okaloosa counties in Florida and ad-
joining parts of Covington County, Alabama, from one-third to one-half
of the stand of cotton, corn and peanuts was destroyed.
In early June the adult weevils began to appear. These attack peanuts,
velvet beans, cotton, beggarweed, and cockleburs in large numbers. As
many as 70 adults were found on a single velvet bean plant, and from 30
to 40 on a single peanut plant was not unusual. They also attack maypop
to some extent.
This weevil has every appearance of being a severe and dangerous
pest to general farm crops. The adults do not fly but are active crawlers.
Evidently the insect breeds parthenogenetically as no males were observed.
Surveys of the ecological habitats and host plant surveys of Thysanop-
tera were conducted as during previous years.
In cooperation with the Plant Board, a survey was made of the pin-
worm situation in the southwestern counties of Florida, where, due to
the abnormally warm January, the heaviest infestation ever recorded
was noted. Under the direction of the Entomologist, George Swank was
employed for two months by the State Plant Board and worked out the
life history, parasites, etc., of the pinworm. The account of his work
will be found in the report of the State Plant Board.

THE FLORIDA FLOWER THRIPS
(Frankliniella cephalica bispinosa Morgan)
State Project 8 J. R. Watson
The flower thrips was again scarce in citrus bloom. The bloom this
year was spread over a very long period, from January to May. Under
such conditions spraying for the thrips was not feasible unless one sprayed
for something else at the same time so that a combination spray could be
used. The application of lime-sulfur reinforced with wettable sulfur at
the rate of 10 pounds per 100 gallons of spray gave some control of thrips.
The addition of nicotine sulfate much improved the kill. The most eco-
nomical method of fighting thrips in citrus groves is the control of weeds
which may be blooming in the winter time.
A heavy infestation of the flower thrips on chrysanthemums in Gaines-
ville gave opportunity for some experiments in control. Lethane combined
with lethane spreader was used with good effect. There was no injury to
chrysanthemums which had been shaded. However, those fully exposed
to the sun were somewhat injured by the application. A bait of molasses
poisoned with Paris green also gave fair control.
An important measure in the control of thrips on both chrysanthemums
and roses was to keep these plants removed from annual ornamentals
which had bloomed a month or two before the chrysanthemums or roses.
In one instance dahlias growing alongside the chrysanthemums were an
evident source of infestation.







Annual Report, 1937


ROOT-KNOT INVESTIGATIONS
Adams Project 12 J. R. Watson, C. C. Goff
and H. E. Bratley
The breeding of resistant strains of lettuce, tomatoes, peppers, Ken-
tucky Wonder beans and cowpeas mentioned in the last report was con-
tinued. Some progress is being made on the resistant strains of lettuce.
Work with tomatoes and peppers looked less promising. However, a large
number of varieties of tomatoes and wild solanums, obtained from the
Plant Pathology Department, are now under test to observe their relative
resistance to root-knot. A resistant strain of Kentucky Wonder beans
obtained from the Alabama Experiment Station is being grown this
season. Selections are being made to obtain an even more resistant strain.
Investigations as to the susceptibility of woody plants, particularly
ornamentals, have been started. Many of these plants have been planted
in badly infested soil to note the degree of infestation.
The practicability of eliminating root-knot from watermelon fields by
growing Crotalaria spectabilis is being investigated. It seems that there
is not sufficient time to prepare the land for this crop and grow it after
the watermelon shipping season is over. Simply sowing the plants in the
watermelon field at the time of the last cultivation, although highly desir-
able from the standpoint of soil fertility, allows too many weeds to grow
on the land to make the elimination of root-knot nematodes at all thorough.
Crotalaria spectabilis does not always do well on the rather high and
dry soils commonly used for watermelon fields; perhaps C. striata would
be better. Furthermore, the Horticulturist believes that the coarser stems
of this species persisting in the soil longer will be desirable as giving the
watermelon plants something to which to cling, thus diminishing wind
injury to young vines.
It appears that the most promising method of dealing with nematodes
in watermelon fields is the two-year rotation, watermelons one year and
Crotalaria striata planted in rows and cultivated and hoed once or twice
in the alternate years. Probably corn could be raised at the same time
without seriously interfering with the elimination of root-knot. Com-
mercial compounds widely advertised for the control of root-knot have
been tested, as have also one containing barium sulfide and nicotine,
others containing 90 percent paradichlorobenzene, sulfuric acid, formal-
dehyde and ethylene chlorhydin. None gave much promise.
Chemically treating strips of soil two feet wide in which the hills of
melons were to be planted also had very little effect on the infestation.
Previous studies of the migrations of nematodes through the soil would
indicate that such a strip would be re-infested within a month.
An intensive study was made of the susceptibility to nematode attacks
of weeds which commonly grow in watermelon fields. Most were found
to be infested but none heavily. The so-called "Mexican clover" (Richardia)
was the one most seriously infested.

INTRODUCTION AND PROPAGATION OF BENEFICIAL INSECTS
State Project 13 J. R. Watson
Work along this line was confined entirely to the efforts to spread
the Chinese ladybeetle, Leis dimidiata var. 15-spilota Hope. The past
spring saw the heaviest infestation of the citrus aphis since 1925. For
the first time since the thorough establishment there the Leis was not
able to give commercial control of aphids in Orange County. The aphids
got a good start during the unseasonably warm January and for some







Florida Agricultural Experiment Station


unknown reason the beetles were slower to start. They became very
abundant later in the season.
A study of supplementary foods of this insect, particularly those
which serve to carry it through the summer months when aphids are
scarce, was continued. It was found that the most important of these
feeds this year was the honeydew given off by Peregrinus maydis in corn
fields. The beetles were not observed feeding on the lantern flies but
only on the honeydew. They will not breed on such material but it un-
doubtedly serves as an important summer food to prolong the life of
the beetles.
Crotalaria striata continues to be the most important of these supple-
mentary summer foods. However, to get this plant to bloom early enough
to be of practical value it will usually be necessary to plant it in places
where it will be protected from frost and will go through the winter. It
was observed that isolated plants usually were not frequented by these
beetles. It is apparently necessary to have rather a thick stand of the
Crotalaria, possibly to afford hiding places for the beetles.
The only food other than aphids on which these beetles were observed
to breed was, as during previous years, the papaya whitefly. However,
it was observed that when these papayas were dusted with sulfur, as is
the common method of combating this whitefly, the larvae of the beetles
were killed and the adults driven off.
Attempts to establish this beetle in other counties have apparently
succeeded in sections of Polk and Broward. Attempts were made to
colonize them in other counties last season but whether they have been
established has not been determined at present. The insect evidently is
difficult to establish in any section, but once thoroughly established it is
able to maintain itself through unfavorable seasons.

THE LARGER PLANT BUGS
State Project 14 H. E. Bratley
The Southern green stink bug, Nezara viridula, was scarcer in citrus
groves in the fall of 1936 than ever previously noted.. Very few instances
of commercial damage were reported. This is correlated with findings
that the parasitization during the previous years by Trichopoda pennipes
about Gainesville approximated 50 percent. About the same percentage
of parasitization was observed in the late summer and fall of 1936.
The pumpkin bug has been scarce in truck gardens this year also.
Apparently these observations would indicate that where the percentage
of parasitization by this fly approaches 50 percent there is little danger
of a heavy outbreak of this insect the following year. f further investi-
ation r t establishing this fact it will give a valuable means of
predicting outbreaks of this serious insec e
The SDepartment is cooperating with the Department of Agriculture,
Queensland, Australia, in an attempt to introduce the parasite into that
state, which has become infested with Nezara viridula.

CONTROL OF FRUIT AND NUT CROP INSECTS-INSECTS
AFFECTING PECAN TREES
State Project 82 S. 0. Hill, J. R. Watson and H. E. Bratley
Pecan Insect Laboratory
Under a cooperative arrangement with the Bureau of Entomology and
Plant Quarantine, U. S. Department of Agriculture, S. O. Hill has taken
up the work on the control of the nut case-bearer at the Monticello labor-







Annual Report, 1937


atory. Although it is too early to make a final report on his spray experi-
ments this season, the spray composed of 1 part of barco to 15 of water,
first used by Fred Walker, seems to be effective. The failure of this
material to give satisfactory results in the past two years may have been
due to its application at an unsuitable season.
Experiments on the use of lye as a spray for this insect were continued.

THE ONION THRIPS (Thrips tabaci Lindin)
State Project 231 J. R. Watson
The onion thrips again gave trouble to celery in Sarasota County,
though the infestation was not as severe as during previous years. A
thorough spraying with a nicotine compound gave best control.
The search for summer hosts of this insect was continued, verifying
the results of such a search of previous years, that the insect is extremely
scarce during the summer time. It was again observed that onions planted
in a place far removed from other vegetation were slower to become in-
fested than those planted near grass or other host plants. Whether
the source of infestations on onions is commonly due to thrips brought
in on sets or to migrations from other host plants is still undetermined.

THE GLADIOLUS THRIPS (Taeniothrips gladioli M. & S.)
State Project 232 J. R. Watson and J. W. Wilson
The study of the life history of this insect was continued. Nineteen
generations were raised in 11 months. As during previous years, the
insect was comparatively scarce during the fall and winter but rapidly
built up a heavy infestation with the arrival of warmer weather. The
carry-over on the bulbs apparently is a minor source of infestation, since
the common source of infestation is on the few volunteer plants that are
allowed to grow in the fields during the summer time. Again the number
of eggs laid by each female and the length of life rapidly decreased during
the hot, humid weather of summer. This thrips is distinctly a spring
pest.
Effective insecticides were rotenone 1 percent with sulfur as a carrier,
pyrethrum 2 percent with sulfur as a carrier, and a 4 percent nicotine
sulfate-lime dust.
Life history on this insect is considered to have been carried for a
sufficient time, but further work on control measures is desirable. A bulletin
on this insect is in preparation.
The insect has been received from gladiolus from Australia. This may
be the original home of the pest. The insect is now generally distributed
over the state in all commercial plantations. However, small dooryard
plantings far removed from such commercial plantations usually are free
of the pest.

BIOLOGY AND CONTROL OF FLORIDA APHIDS
State Project 234 A. N. Tissot
More species of aphids were collected in Florida during the past year
than in any year since a systematic study of the aphid fauna was started.
Seventy-one species were represented in the 123 collections of aphids
taken, of which 7 species have not been known to occur in the state
heretofore.







Florida Agricultural Experiment Station


The citrus aphid, Aphis spiraecola Patch, was more numerous and did
more damage during the spring of 1937 than at any time since 1925 when
it first became thoroughly established in Florida.
Nineteen species were added to the known lists of plants from which
aphids have been taken in Florida.

THE PEPPER WEEVIL (Anthonomus eugenii Cano)
State Project 263 C. C. Goff
Observations on the spread of the pepper weevil were continued. Three
foci of infestations were found this year in Manatee County. One had
for its center the field of hot peppers mentioned in the previous report
which were not cleaned up. By November this field had re-infested every
pepper field within half a mile. By December the infestation had increased
tenfold and had spread to fields somewhat farther removed. At this time
infestations were found in two fields north of the Manatee River, one
rather heavy. One of these pepper fields was entirely destroyed in April,
before the owner had harvested a single pepper, so abundant had the
weevils become that any chance of obtaining a crop was hopeless. The
other field was destroyed with the exception of one row around the edge
of the field. In this row the pepper weevils continued to breed and were
still there in May.
A light infestation was found also in Sarasota County, the first out-
side of Manatee. This field was promptly destroyed.
Observations this year confirmed those of last season that a thorough
clean-up after the shipping season is over gives thorough control of this
insect. It is believed that if a complete destruction of the pepper plants
could be obtained it would be entirely possible to eradicate the pest in a
few years.
Bulletin 310 was published on this insect.







Annual Report, 1937


HOME ECONOMICS

The year's experimental work in the Department of Home Economics
has covered a wide range of studies on foods and nutrition. These studies
include active cooperation with the Department of Chemistry and Soils
on the mineral content of vegetables grown on different soil types and on
the vitamin C content of citrus fruits and leafy vegetables, with Animal
Husbandry on pathologic changes in tissues and organs of animals on
deficient rations, with Plant Pathology on the jelling properties of certain
varieties of grapes, and with the State Apiary Inspector on the study
of the more important Florida honeys.

A STUDY OF THE PATHOLOGIC CHANGES IN TISSUES AFFECTED
BY DEFICIENCY DISEASES OR BY TOXIC SUBSTANCES
Purnell Project 222 C. F. Ahmann
Cobalt Deficiency.-In the study of the effect on cattle of cobalt de-
ficient rations it was difficult to find specific gross external or internal
symptoms. Roughness of coat, loss of appetite, listlessness, retarded de-
velopment, and emaciation were observed, but these symptoms have been
encountered in various forms of malnutrition. The blood picture of these
cattle showed anisocytosis, poikilocytosis, and an increase in the percentage
of lymphocytes; a picture that is likewise typical of anemia. In histological
sections of the organs of these animals pigment deposition (hemosiderosis)
in both liver and spleen and fibrosis infiltration and fatty degeneration of
liver were noted. The heart also showed myocardial degeneration and
fibrosis infiltration. None of these pathologic changes, however, were noted
in E-79, the only animal slaughtered after receiving cobalt.

AN INVESTIGATION OF HUMAN DIETARY DEFICIENCIES IN
SELECTED COUNTIES OF FLORIDA, WITH SPECIAL REFER-
ENCE TO NUTRITIONAL ANEMIA IN RELATION TO HOME
GROWN FOODS
Purnell Project 255 C. F. Ahmann and 0. D. Abbott
From the investigation of human dietary deficiencies in certain counties
of Florida three articles have been prepared. Salient points brought out
in these papers were that (1) in a general way the incidence of anemia
in the children of several schools was related to the iron content of the
soil, (2) milk from a cow long maintained on a ration low in iron induced
in young rats a greater degree of anemia than did milk produced on a
normal ration, (3) satisfactory regeneration of hemoglobin in anemic rats
resulted only when the animals were fed vegetables (turnip greens) of the
highest iron content (204 ppm.).
During the current year the work has been extended into Citrus, Jef-
ferson and Holmes counties. Hemoglobin values were determined on the
children in the first three grades of 12 schools and the predominant soil
types for each district were classified for correlation with the incidence of
anemia. Samples of vegetables grown on the home farms were collected
for analysis and dietary studies were made on each child examined. The
data indicate that the children whose food was grown on the better soil
types have a higher percentage of hemoglobin than those whose food was
produced on soils of lower fertility.







Florida Agricultural Experiment Station


In cooperation with the Department of Chemistry and Soils vegetables
from these counties were analyzed for iron, calcium and magnesium. Again
it was found that vegetables grown on the better soil types often contained
100 percent more iron than the same variety grown on less fertile soils.
During these investigations evidence has accumulated which indicates
that in addition to iron deficiency many children are suffering from other
mineral deficiencies. These deficiencies will now be studied in connection
with the anemia investigations.

THE CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF
SEVERAL FLORIDA HONEYS
Purnell Project 270 C. F. Ahmann and O. D. Abbott
Six of the more important honeys produced in Florida have been
analysed. It was found that Tupelo and Black Mangrove contained the
highest percentage of levulose and have an immediate direct polarization
at 20* C. of -26.6 and -25.8. These were much higher values than those
of the other honeys examined. Black Mangrove and Saw Palmetto honeys
were highest in total ash, soluble ash and alkaline soluble ash.
A study was then made of the nutritive value of honey in the feeding
of babies and puppies. In this work honey was substituted for glucose
in the evaporated milk-glucose formula. On this food both babies and
puppies gained weight and were healthy, normal individuals. The honey
was found to be quite laxative and at first was used in smaller quantities
than the glucose.
Because of the high nutritive value of royal jelly in the feeding of bee
larvae, a study is now being made of its chemical composition and nutri-
tive value.

A STUDY OF THE JELLING PROPERTIES OF SEVERAL VARIETIES
OF FLORIDA GRAPES
Purnell Project 271 0. D. Abbott
In cooperation with K. W. Loucks, Assistant Pathologist, a study has
been made of some of the most promising varieties of grapes grown in
the state in order to determine their suitability for use as dessert fruit
and for the preparation of jelly and sweet juice. Twelve varieties of
grapes have been tested. From these studies it has been concluded that
their use as dessert fruits and for the preparation of sweet juice offers
the most promising possibilities. All the grapes were too low in pectin
for commercial jelly, though several varieties, Fredonia, Lomanto, Bailey,
Carman, Munson and Beacon made soft jellies of good flavor suitable for
home use. The Munson, Beacon, Bailey, Carman, and Fredonia produced
bright red juices of from fair to good quality. The grapes found to be
best suited for dessert were Wapunka, Fredonia, Lomanto, Carman and
Beacon, listed in the order of preference.
Work on this project has been completed.

STANDARDIZATION OF HOME CANNED TOMATOES AND
TOMATO JUICE
Purnell Project 272 0. D. Abbott
By the use of Tillman's indophenol method, the vitamin C content
of fresh tomatoes, canned tomatoes, and tomato juice expressed as mg.
ascorbic acid per 100 ml. of juice has been determined. It has been found






Annual Report, 1937 77

that the home canned tomatoes and tomato juice preserved according to
directions given by Florida home demonstration agents contain as much
vitamin C as the five commercial brands used as standards.

INVESTIGATION OF VITAMIN C CONTENT OF FLORIDA FRUITS
AND VEGETABLES
R. B. French and O. D. Abbott
Results of this investigation are reviewed in the report of the Depart-
ment of Chemistry and Soils.







Florida Agricultural Experiment Station


HORTICULTURE

Work in the Department of Horticulture was carried on under projects
dealing with maturity of citrus, cold storage of citrus fruits, citrus juices
and pulps, pecans, tung oil, miscellaneous minor fruits, ornamentals, vege-
tables, and fumigation of various horticultural materials.
Results obtained in cold storage experiments dealing with the amount
and kind of refrigeration necessary, and the type of wrappers to use for
successful cold storage of oranges and grapefruit were published in sta-
tion bulletins.
Further studies have developed a very economical method of keeping
citrus fruit for three to four months at 33 to 37 F. by covering with 10
ounce canvas tarpaulins, a large number of boxes of fruit stacked in the
refrigerated rooms. Small quantities of iodine crystals placed between the
boxes under the cover reduced considerably the -amount of decay in the
fruit in these experiments, and the loss in weight of the fruit was retarded
by keeping the canvas cover damp by spraying with water. These findings
are of value to the citrus industry as they make available for still air
storage the large commercial cold storage plants. The covering was found
to be comparable in efficiency to individual moisture-proof wrappers and in
addition allow for no accumulation of respiratory gases.
The 1936 production of American tung oil was the largest of record.
A very large percentage of the present acreage came directly or in-
directly from the ten original trees which were planted in 1912 and 1914
on the Horticultural grounds. With the appearance of bronzing several
years ago this young industry was seriously threatened, until workers
of this Department found that the trouble was mostly a zinc deficiency
and could be corrected with zinc sulfate applied either as a foliage spray
or to the soil about the trees. This work has been continued and numerous
materials in addition to zinc sulfate are being investigated.
Frotscher pecan trees growing in soils managed according to the system
of fertilizing and cover cropping developed by this department have pro-
duced five consecutive crops and this spring there was a heavy bloom and
subsequent set of nuts which indicate good prospects for the sixth con-
tinuous annual yield.
In the study of pecan products, several gallons of oil were expressed
from pecan kernels, and small quantities of pressed pecans, pecan butter,
and pecan meal were made with the pomace.
Truck crop investigations brought out some interesting findings in
connection with studies on cover crops, fertilizers, and fertilizer place-
ment, magnesium and soil acidity. Progress was also made in the continued
strain tests of several important vegetable crops.

VARIETY RESPONSE OF PECANS TO DIFFERENT SOIL TYPES,
LOCALITIES, ETC.
State Project 46 G. H. Blackmon
The 1936 pecan production in that part of Florida east of the Suwannee
River was the largest for several years, but was light and scattered west
of this area. In Jefferson and adjacent counties the light crop was due
mainly to'severe tree damage caused by the storm of Sept. 2, 1935. The
loss in the counties west of the Apalachicola River was caused by a storm
on July 31, 1936, which destroyed 40 to 80% of the nuts, the greatest
amount of damage being done in the Walton County orchards.
Where summer cover crops were grown in commercial orchards they
consisted mostly of Crotalaria spectabilis, although some growers planted






Annual Report, 1937


C. striata and C. intermedia for the production of organic materials. In
addition to these, Kudzu is grown in several orchards in Jefferson County,
and where the vining growth is kept cut out of the trees results so far
indicate that this may possibly be a good crop to grow in pecan orchards
located on suitable soils. A common practice is to plant velvet beans
between the rows where corn is grown in the orchard, and these crops
are generally grazed off with cattle and hogs after the corn is gathered.
The acreage of soil conserving winter legumes was somewhat larger
in 1936-37 than formerly. Austrian peas and hairy vetch were the crops
most extensively planted, but several growers made an effort to establish
Augusta vetch (Vicia angustifolia) in their orchards for a continuous re-
seeding winter green manure legume.
Soil Amendments.-Pecan trees of different varieties affected with
rosette continued to show varying degrees of growth response to soil
application of 89% zinc sulfate. During 1936 Moore and Curtis trees
produced much better growth of twigs and leaves, while Stuart and Money-
maker were slower and more irregular in their response following the
annual soil application of 2 pounds per tree of the zinc sulfate. Iron and
copper sulfates are being applied to the soil in connection with zinc
sulfate where trees have been slow in growing out of a rosetted condition,
but no definite conclusions in regard to their use can be reported at this
time.
This project has been discontinued and work will be carried under
State Project 48.

COOPERATIVE FERTILIZER TESTS IN PECAN ORCHARDS
State Project 47 G. H. Blackmon
The trees in all fertilizer experiments except in Bradford County and
one Moore in Jefferson County suffered severe damage from storms and
the records do not show what the results would have been under normal
conditions. The crop failure for 1936 in the other experiments in Jefferson
and Leon counties was due to the high winds of September 1935 which
caused defoliation and subsequent new growth, thus depleting the food
reserves and weakening the trees to such an extent that there was no
differentation of pistillate flowers. The loss in Holmes and Walton coun-
ties occurred in July 1936 when a storm swept over that area and blew
off a high percentage of the nuts and did considerable damage to the trees.
Growth.-When all varieties are considered the growth increments of
the trunk cross-sectional areas were generally greatest for the fertilized
Moneymaker, Moore and Curtis trees. With most treatments, however,
the trees in the fertilized plots grew more than those in the unfertilized
checks, and likewise in a majority of cases where sulfate of ammonia
was applied in addition to the regular spring applications the trees made
more growth than where the extra nitrogen is omitted.
Yields.-Pine timber protected the orchard in which the Moores (set
1912) are located and the high winds of September 1935 did not severely
damage the trees and consequently a good crop of nuts was produced in
1936. In these experiments the Moore continued to rank first in quantity
of nuts produced, while Curtis was second and Kennedy third. Moore
and Kennedy showed the greatest response to fertilizers, although the
trees in two fertilized Curtis plots gave greatly increased yields. With
all other varieties which produced nuts even though the crop was light,
the yields in the fertilized plots, except one, were consistently larger than
they were in the checks.






Florida Agricultural Experiment Station


STUDIES OF VARIETIES OF PECANS AND OTHER
HORTICULTURAL NUT-BEARING SPECIES
State Project 48 G. H. Blackmon
Growth and yield of trees in the pecan variety test orchard at the
Main Station were better in 1936 than in 1935. A number of varieties
produced varying quantities of just a few nuts to 28 pounds average
per tree for the Moneymaker.
The seedling black walnut trees continued to respond to soil applica-
tions of 89% zinc sulfate as did the pecans treated in the variety orchard.
The 89% zinc sulfate has been applied on the soil at the rate of 2 pounds
per tree in the pecan variety test orchard when rosette appears in the
leaves, and /4 pound per tree in the black walnut tests.
PECAN PRODUCTS
Work with pecan kernels was continued and several new products
developed.
Pecan Oil.-Approximately four gallons of oil were extracted from
the kernels of 11 varieties of pecans during January and February. The
oil expressed from the raw cold kernels with 12 tons pressure ranged
from 17.6% of the weight of the kernels to 31.8%. A small quantity of
Curtis kernels was divided into two lots of unequal weight and heated.
One lot which was allowed to cool at room temperature and then pressed
cold yielded 56.2% oil; and the other lot pressed while the kernels were
hot produced 57.0% oil; and with the same amount of pressure (12 tons)
the raw kernels pressed cold yielded 30.8% oil (all percentages are based
on the weights of the kernels and not of the whole nuts).
Pressed Pecans.-This product is the pomace or residue remaining after
the oil has been expressed from the raw, cold pecan kernels. It retains
the pecan nut flavor and doubtless could be used as a substitute for whole
kernels although the oil content would be lower.
Pecan Butter.-This product was first made by grinding the pomace
of the cold-pressed raw kernels, but the oil was not released sufficiently
to give the desired oiliness. In subsequent tests it was found that an
excellent oily product with the desired pecan flavor could be made by
thoroughly heating, but not browning, the pomace in pecan oil before
grinding.
Pecan Meal.-The first meal was made from the pomace of-the cold-
pressed raw pecans. Later tests showed that a much smoother product
could be produced by heating the kernels, pressing out the oil, and then
grinding the pomace as desired.

PROPAGATION, PLANTING AND FERTILIZING TESTS WITH
TUNG OIL TREES
Hatch Project 50 R. D. Dickey and G. H. Blackmon
The 1936 yield of tung oil in the South will not be known definitely
until all fruit has passed through the pressing plants, but it doubtless
will be over 2,000,000 pounds, a high percentage of which was produced
in Florida plantings. Although this is a comparatively small percentage
of the tung oil used annually in the United States, it is of considerable
significance as it definitely establishes this as a tung oil producing area
and it must be so recognized in future considerations.
In the fertilizer experiment on the Station grounds the check trees
continued to produce least growth and lowest yields. Lightest production






Annual Report, 1937


in the fertilized plots amounted to 22.7 pounds of air-dried seed per tree,
and the highest 36.4 pounds, compared with 17.7 pounds per tree for the
unfertilized checks.
During 1936 a large scale experiment was initiated in Jefferson County
near Lamont to determine the effects of cover crops and various types
of fertilization on growth and yield. There was a good yield of tung
fruit in 1936 in all plots, but in 1937 it will be spotted due to losses during
the freeze in March of this year.
Continued warm weather during January caused tung trees to start
forcing into growth and by the first week of February most of the flower
buds had either opened or were ready to break into full blossom. Conse-
quently, during subsequent periods in February and March when the
temperature dropped to near freezing and below, there was considerable
cold damage in many plantings. West of Tallahassee practically all fruit
was killed in the bloom while east of this point the loss was scattered and
irregular. In most instances greatest damage was done to the bloom
and to young trees, but in one locality a high percentage of the trees
in a two year old planting was killed to the ground. Some plantings
escaped injury except to a very slight extent in low places, while in others
there was every gradation from a complete loss in the low areas to none
on the higher elevations and in all plantings where damage occurred the
injury was often quite irregular.
The amount of cold damnageinay-given- locality is closely correlated
with its temperature history and the extent of cold protection which is
afforded. One of the station plantings immediately adjacent to the campus
experienced no injury while on another less than two miles distant (air
line) the entire crop was destroyed. The original 10 trees on the horticul-
tural grounds escaped injury to either fruit or twigs.
Indications point to a much lighter crop for 1937 than that of 1936.
All yields in 1937 of worthwhile quantities will be produced in the plantings
receiving the best cultural management and where cold losses did not
occur.
Further studies were made on propagation in an effort to determine a
more suitable asexual method adaptable to use with tung trees and a
great amount of pollination work has been done similar to that previously
reported, looking to the development of pure line, high yielding varieties.
Some seedlings grown from seed produced in early crosses are now entering
their fourth year.
Studies on the use of zinc sulfate and other soil amendments were
continued. However, since this work is now being carried cooperatively,
results are reported under Purnell Project 238.

TESTING OF NATIVE AND INTRODUCED SHRUBS AND
ORNAMENTALS AND METHODS FOR THEIR PROPAGATION
Hatch Project 52 R. D. Dickey
Specific information is in constant demand for various species of
ornamentals regarding their propagation, culture and adaptation under
Florida conditions and much work has been done in this connection.
During the year 34 species were received from the United States Depart-
ment of Agriculture for testing.
ROSES
Variety Test.-A total of 26 rose varieties has been planted in the
trial garden for observations and records. The planting is being carried
under cultural conditions similar to those existing in most areas through-






Florida Agricultural Experiment Station


out the state. The number of blooms per plant produced annually and
the time and distribution of flower production, as well as vigor of the
different varieties tested, are the principal data being accumulated.
Rootstocks.-A selection of several species of commonly used root-
stocks has been made for testing purposes. These rootstocks are used
in propagation studies, as well as to test their value under conditions of
soils and climate existing in Florida when the varieties most frequently
grown are worked on them.
TREES AND SHRUBS
On the whole, cold damage to ornamental trees and shrubs was rela-
tively light during the past winter in this area. Much information on
the cold resistance of numerous species has been obtained over a period
of several years and will prove of value in determining the adaptability
of plants to the northern areas of the state.
There is an ever-present need for specific data regarding the time and
extent of flowering of the many ornamental trees and shrubs in the areas
to which such plants are adapted. This type of information is lacking
in some instances, particularly for the more recently introduced species
which have become popular as ornamentals. Such information is being
accumulated for the entire state as rapidly as possible.
Hollies.-Ilex rotunda specimens observed in northern Florida indicate
that this species of Asiatic holly warrants a much wider use and popularity
than it now enjoys. It grows pyramidal in shape and develops into a
close compact head and makes a most beautiful small tree which produces
small red fruit in great abundance. Seed planted immediately after they
had been cleaned from berries gathered in November showed a high
percentage of germination in four months, but a few plants were showing
above the soil in six weeks. Seed cleaned from mature berries gathered
in March and planted at once with similar treatment as those gathered
in November have given a very low percentage of germination to date.
There is great variation in specimens of Iles opaca growing in Nature
and in cultivation, some being much more desirable forms than others.
A collection of asexually propagated plants of different types as they
become available is being made.
BULBS
Narcissus.-The experiments now in progress with Paper White nar-
cissus have been enlarged to include a determination of the factors affecting
blooming. Studies are being made also to obtain information as to the
exact behavior of the different categories of the bulb, namely slabs, round
and mother bulbs.

COVER CROP TESTS IN PECAN ORCHARDS
State Project 80 G. H. Blackmon
Trees in the cooperative cover crop experiment were damaged by
high winds of September 1935 in Jefferson County which caused them
to go into dormancy in a somewhat weakened condition. In the Walton
County experiment a storm in July 1936 caused considerable injury and
defoliation of the trees and blew off about 60% of the nuts. Therefore
the results for 1936 are not what they would have been under more nearly
normal conditions.
An experimental pecan planting consisting of 104 Moneymaker and
99 Moore trees was made in January of this year on the North Florida







Annual Report, 1937


Station Farm at Quincy. Tree response to green manure crops, fertilizers
and methods of soil management will be included in this experiment.
Green Material.-In the Jefferson County experiment the summer
growth, which consisted of Crotalaria spectabilis and natural vegetation,
was quite good. However, the hairy vetch produced a light yield of green
material due to a thin stand of plants.
Augusta vetch seed in small lots were planted in the experiments in
Jefferson and Walton counties, and in the pecan variety orchard at
Gainesville. In both locations the plants made satisfactory growth as
the soil was well inoculated from crops of Austrian peas and hairy vetch
which had been successfully grown during previous years. The size and
density of the planting at Gainesville are shown in Fig. 2.



N.,
S.


















Fig. 2.-Augusta vetch (Vicia angustifolia) growing in the pecan variety
orchard at the main station.

Tree Growth.-In the Jefferson County experiment the effects of cover
crops and fertilizers on the growth showed about the same correlation as
in previous years. However, there were no consistent differences in the
Walton County experiment where green material from only two years'
growth of winter legumes has been returned to the soil, but in all plots
where sulfate of ammonia is being applied the trees have made the greatest
growth increment.
Yields.-Nut production in 1936 continued to be highest, except in one
Moore plot, where winter legumes are being grown in the Jefferson County
experiment. In Walton County the yields were low, due partly to losses
caused by the nut case-bearer and the storm of July 1936.
In Jefferson County the bloom and subsequent set of nuts was heavy
in the winter legume plots but lighter where only the summer crops are
being grown. In the Walton County experiment there was a fair bloom
but the nuts set were greatly reduced in number by a heavy infestation
of nut case-bearer. The yield should be much heavier in 1937 than it was
in 1936.







Florida Agricultural Experiment Station


Fig. 3.-Hairy vetch growing in the pecan cover crop experiment in
Walton County.

PHENOLOGICAL STUDIES ON TRUCK CROPS IN FLORIDA
State Project 110 F. S. Jamison
Fertilizer studies with a number of truck crops were conducted during
the past year. Fertilizer tests with watermelons indicated that an organic
nitrogen carrier was desirable in the fertilizer mixture. Where one-half
of the nitrogen was derived from organic material there were 550 melons,
averaging 26.37 pounds, per acre. Where the nitrogen was supplied entirely
by inorganic materials there were 440 melons, averaging 26.22 pounds,
produced on an acre. The addition of soluble magnesium sulfate to the
fertilizer did not increase the number or weight of melons produced. The
yield of melons was decidedly reduced where additional nitrate of soda
was used as a top-dressing. Five hundred and thirty melons per acre
were produced on those plots receiving the entire supply of nitrogen before
the crop was planted. Where additional nitrogen as nitrate of soda was
applied just previous to fruit setting the yield was 417 melons per acre
and where the application was deferred another two weeks the yield was
395. Nitrogen from nitrate of potash also was tried as a side or top-
dressing. Where this material was applied just previous to fruit setting
the yield was 500 melons per acre and where applied two weeks later the
yield was 517 melons. It should be realized that this work has been
carried on for only one season. At least two more years' results will be
necessary before any definite conclusions can be made.
Sodium nitrate, ammonium sulfate and cottonseed meal were used
alone and in combination as a source of nitrogen in fertilizing peppers,
beans, Irish potatoes and cucumbers. To one-fourth of these fertilizer
mixtures was added soluble magnesium sulfate, to another fourth insoluble
magnesium from dolomitic lime, to another magnesium in both soluble
and insoluble forms, while the remainder of the mixtures had no mag-







Annual Report, 1937


nesium added. The land on which this work was conducted was a very
uniform piece of Arredondo fine sandy loam soil. Each of the various
treatments was replicated four times.
There was considerable variation in growth and yield of crops receiving
the different treatments. Ammonium sulfate and cottonseed meal appear
to be of about equal value as a source of nitrogen. The yield from those
plots receiving sodium nitrate as the only source of nitrogen was consider-
ably lower than that of the plots fertilized with cottonseed meal or am-
monium sulfate. Where magnesium was added to fertilizer in which the
nitrogen was in the form of sodium nitrate, the yield was further de-
creased. This effect appeared when magnesium was added as either the
soluble magnesium sulfate or in the insoluble dolomite forms. Magnesium
used with ammonium sulfate appeared to have a beneficial effect on the
growth and yield of the crop.
During the past year fertilizer placement studies have been carried
on with tomatoes, beans, potatoes, peppers and cucumbers. The major
part of the work has been done at the Main Station, although field trials
have been made in cooperation with the Everglades and Sub-tropical
Stations.
The fertilizer was applied to the soil by broadcasting over the entire
area, by mixing it with the soil in the row where the seeds or plants were
to be planted, and by applying it in bands two inches wide, placed at
approximately the depth of the seed and 2% inches on each side of the
seed row. In the plantings at Gainesville each treatment was replicated
four times.
The band method of applying fertilizer gave outstanding results with
cucumbers, peppers and tomatoes. Broadcasting of the fertilizer gave
the highest yield of potatoes, while beans yielded highest where the fer-
tilizer was mixed in the soil of the row. The "mixed with the soil in the
row" method gave the lowest yield of all crops with the exception of beans.
A preliminary study of the root growth of beans, potatoes and cucum-
bers was made to determine the relative position of the roots of these
crops as affected by the placement of the fertilizer.
Field studies on the use of magnesium, manganese and other elements
on the growth and yield of Big Boston lettuce was conducted in the lettuce
growing area of Alachua County. While no effect on yield was secured
from the use of either magnesium or manganese, it was observed that
magnesium had a definite effect on the maturity of the crop. Where
magnesium sulfate was applied at the rate of 125 pounds an acre, the
crop appeared to mature more uniformly than it did where no magnesium
was used.

RELATION OF NITROGEN ABSORPTION TO FOOD STORAGE,
GROWTH AND REPRODUCTION IN PECANS

Adams Project 165 G. H. Blackmon
A study of the nitrogen content of dormant pecan twigs cut from
trees growing under different methods of soil cultivation and fertiliza-
tion was made. The twigs analyzed were representative samples of the
one year old growth cut in January from branches located about half-
way between the lowest and topmost parts of the trees.
Additional nitrogenous material applied during the summer seemed
to have had a positive effect on the amount of nitrogen stored in the
dormant twigs, in all determinations made except two. Highest percentage
of total nitrogen was found in twigs cut from Frotscher trees located in







86 Florida Agricultural Experiment Station

plots where legumes are being grown in winter and summer and sulfate
of ammonia applied during July. On a dry weight basis the nitrogen
content of the dormant twigs from all varieties ranged all the way from
a low of 0.82 percent to a high of 1.15 percent.

VARIETY TESTS OF MINOR FRUITS AND ORNAMENTALS
State Project 187 G. H. Blackmon and R. D. Dickey
Blackberries.-Continued warm weather in midwinter caused plants
to force an early growth which was later damaged by cold and the fruit
yields were much lighter than in former years. In fruit production Advance
ranked first, Marvel second, and Youngberry third. "Boysenberry", Ness
No. 2, Ness No. 6 and Mercereau did not produce fruit this year because
of either cold injury or the failure of the plants to bloom.
Avocados.-The trees being tested at the Main Station are Mexican
and hybrid Mexican varieties. They have made a remarkable recovery
from the severe injury caused by the freeze in December 1934, and no cold
damage was experienced this past winter except a slight burning along
the edges of a few leaves. A good crop of fruit was set this year, the
first since 1933.
Peaches.-In the work with nematode-resistant peach stocks, eight vari-
eties were budded into common peach seedlings and the trees planted on
newly cleared land at the North Florida Station. The following eight
peach varieties were planted at Quincy in January of this year: Myro,
Bokhara, P. I. No. 36485, P. I. No. 55886, P. I. No. 55888, P. I. No.
63850, P. I. 63851, and P. I. No. 63852. These trees are being grown
for a source of seed from which seedling stocks will be produced for
further studies.

STUDY ON THE PRESERVATION OF CITRUS JUICES AND PULPS
State Project 189 A. L. Stahl
Canned grapefruit hearts and grapefruit juice were found to be in
excellent condition and with very little change in taste and only slight
discoloring after three years in storage at 32 and 37 degrees F. That
held at higher temperatures of 48 degrees F. and room temperature (75-80
degrees F.) had taken on considerable "off tastes" and had become dis-
colored (amber brown). The colder the storage temperature the better
the condition of the canned grapefruit product.
Further studies on the cool storing of orange and tangerine juice,
without actually freezing it, for periods up to two weeks were made.
Numerous chemicals and other substances were added in small quantities
as preservatives to the juice directly after extracting. Wheat and oat
flour and extracts from these were found to be good preservatives, allow-
ing very little change in appearance or taste of the juice after 2 weeks
at 32 to 42* F.

COLD STORAGE STUDIES OF CITRUS FRUITS
Purnell Project 190 A. L. Stahl, J. C. Cain
Investigations now in progress include studies on pre-treatments, wrap-
pers, still-air storage and control of storage decay, on round oranges,
Mandarin oranges and grapefruit.
Stem-end rots and Penicillium mold, the two most important citrus
storage decays, were controlled by placing iodine and ammonium hydroxide







Annual Report, 1937


(small quantities) inside moisture-proof wrappers and in air-tight con-
tainers which held the fruits and were ventilated at intervals. Both
iodine and ammonium carbonate were found to be outstanding as controls
among many substances used as impregnations in wraps or as substances
added inside the wraps, or added to surface coverings.
An extensive study was made on the keeping quality of the various
citrus types belonging to the Mandarin group. The following types were
placed at several temperatures at high humidities in various wrappers
and surface-treatments: Tangerine, Temple, King, Tangelo and Satsuma.
Tangerines kept very poorly at all temperatures: and under all treatments,
breaking down physiologically at the colder temperatures and decaying
rapidly at the higher ones. Other Mandarin types reacted similarly to
round oranges, keeping best in moisture-proof wrappers, brytine surface
treatments, and "still air" storage at temperatures around 37 degrees F.
The most outstanding development has been the use of 10 oz. canvas
tarpaulins to cover a large number of stacked boxes of fruit in cold storage.
This covering was found to be comparable in efficiency to individual
moisture-proof wrappers and in addition allowed no accumulation of
respiratory gases under the cover. Valencia oranges and Marsh Seedless
grapefruit kept 4 months in splendid condition under the above treatment
at 33 to 37 F. Loss in weight was further prevented by keeping the
canvas cover damp. Decay was reduced considerably by placing iodine
crystals (small quantities) under the cover between the boxes. This
system of covering provided a very economical method of storage.
Several manuscripts were published as Station bulletins under the
head "Cold Storage of Florida Citrus Fruits".
MATURITY STUDIES OF CITRUS FRUITS

Purnell Project 237 A. L. Stahl
Physical and chemical characteristics of citrus fruits from bloom to
maturity have now been systematically studied continuously for the third
season. Comparisons and correlations were made between these char-
acteristics and the degree of ripeness of the fruit. It was found that
internal chemical changes which accompany the ripening of citrus types
are to a greater or less extent reflected in a progressive change in both
outward appearance and physical condition. It was hoped that there
must exist some critical balance between anabolic and catabolic functions
or some typical break in the progressive chemical changes which would
serve not only as a criterion for ripeness but also as a measure of quality.
Although this ideal so far has not been realized it has resulted in a useful
amount of knowledge regarding the physiological and biochemical pro-
cesses accompanying the ripening of fruit.
During the period of ripening the weight of the fruit increased. This
change was accompanied by an increase in the weight of pulp and in
the amount of soluble solids and sugars in the juice and fruit. The pro-
portion of cell wall material in the pulp and the acid in the juice decreased.
As maturity is reached the increasing factors tended to reach a maximum
value and the decreasing factors a minimum value. There was no sig-
nificant increase in the nitrogen content of the juice nor in the ash
content of the juice during the ripening period.
Samples were taken also of the various tissues of fruit picked at
regular intervals throughout the season and the amount of total ash
was determined. This ash is being used to determine the amount of the
major and minor elements in the various tissues and the changes in the
amounts with maturity of the fruit.







88 Florida Agricultural Experiment Station

Much work was done during the year in physiological gradients in
citrus fruits. It was found that various portions of citrus fruits, particu-
larly the regions near the calyx and stylar ends, differ not only in their
morphology but also in their physical and chemical characters.
In mature Valencia oranges the following characters increased in amount
in both juice and pulp from the calyx to the stylar end: pH, specific gravity,
total nitrogen, total sugar, dry matter and carotinoid content. Total ash
and acidity were found to be greatest in the calyx end, decreasing in amount
toward the stylar end.
A radial equatorial gradient was found in the ash of the pulp, the ash
increasing toward the central core.
A greater amount of oil was found in the peel of the stylar end of
mature Pineapple oranges than in that of the calyx end. More weight was
lost through the peel of the calyx half than through that of the stylar half.
The gradient in total sugar in the peel is just the reverse of that in
the pulp and juice. In the peel the total sugars are highest in the calyx
end, decreasing in amount toward the stylar end.

A STUDY OF THE RELATION OF SOIL REACTION TO GROWTH
AND YIELD OF VEGETABLE CROPS
Adams Project 268 F. S. Jamison
A series of plots 1/16 acre in size has been established on Arredondo
fine sandy loam. The degree of acidity of these plots has been adjusted
by the use of lime and sulfur so that a range in acidity now exists from
pH 4.8 to pH 7.3. The acidity value of the various plots is measured at
regular intervals during the year. Attempts are made to adjust the soil
acidity by additional applications of lime or sulfur previous to planting
time.
In 1936 tomatoes, eggplants, peppers and cucumbers were grown on
the plots. During the present season these same crops and in addition
green beans have been grown on each of the treatments. There was con-
siderable variation in the response of the various crops to the different
degrees of acidity. Beans produced 162 bushels per acre when grown on
plots having a soil acidity of pH 5.6-5.8. At pH 6.0 the yield was 130
bushels per acre, while at 5.3-5.5 the yield was 131 bushels. Eggplants,
cucumbers, and tomatoes produced greatest yields on plots having a pH
of 5.0-5.2. Peppers also performed well on plots having low pH values.
The highest yield of peppers was obtained on plots having a hydrogen-ion
concentration of pH 5.3-5.5. Lowest yields were obtained on all of the
test crops when grown on those plots above pH 6.4.
Additional work is being conducted under controlled greenhouse con-
ditions to determine the optimum degree of acidity for vegetables when
grown on specific soil types.

SELECTION AND DEVELOPMENT OF VARIETIES AND STRAINS
OF VEGETABLES ADAPTABLE TO COMMERCIAL
PRODUCTION IN FLORIDA
State Project 282 F. S. Jamison
Varieties of potatoes, peas, cabbage, lettuce, cucumbers, and miscel-
laneous vegetables were grown at the Main Station. Included in the
potato varieties were 22 lots of seedlings developed by the USDA. Certain
of these strains proved to be exceedingly resistant to early blight, and
produced large yields of very smooth potatoes. The more promising







Annual Report, 1937


strains will be planted for further trial. None of the strains are as yet
available for commercial production.
In the cabbage trials Resistant Detroit, a variety developed for re-
sistance to cabbage yellows, produced as well as Copenhagen Market. The
round heads were approximately the same size and shape as those produced
by Copenhagen Market.




















Fig. 4.-Field plots where vegetable research is conducted.

Hundredfold and Laxton Progress peas yielded better than the com-
monly grown variety Little Marvel. Not only did these two varieties
yield more peas but the pods were considerably larger and more desirable
for marketing purposes.
Fifty-two strains of lettuce were planted at several dates. The variety
New York, Strains Number 12 and 42, were found to be superior to other
strains. New York 515 produced hard but very small heads. Even these
three strains were not satisfactory for commercial production as only
approximately 25 percent of the plants produced firm marketable heads.
California Wonder pepper continued to produce well in comparison
with other varieties. This variety consistently brings a higher price
during the marketing season than do the thin walled varieties such as
Ruby King.
Selection work was begun with Porto Rico sweet potatoes. High and
low yielding plants have been selected and progeny from these plants
are now growing on experimental plots. During the past year certain
plants grown from individual roots yielded 500 percent more potatoes
than did other lots. Whether this difference in yielding ability is in-
herited or due to the influence of other factors is being determined.
Breeding work with the Honey Rock cantaloupe, a variety partially
resistant to mildew, has been discontinued. Selection of a desirable market
type of African Squash by the process of selfing plants producing desirable
fruit is being continued.
Plantings of perilla were made of seed produced at Gainesville last
season. Three lots, Perilla nankinensis, purple red, P. nankinensis green
and P. ocymoides, were planted. However, none of the seed germinated
under field conditions. Chia, another plant the seed of which are used








90 Florida Agricultural Experiment Station

for the same purpose as perilla seed, was planted. At present this plant
is growing quite well.

EFFECTS OF VARIOUS GREEN MANURE CROPS ON GROWTH,
YIELD AND QUALITY OF CERTAIN VEGETABLE CROPS
State Project 283 F. S. Jamison
Crotalaria spectabilis, C. intermedia, cowpeas, Sudan grass, velvet
beans and soybeans were planted in a series of plots in 1935 and 1936.
Two series of plots were not seeded to cover crops but the plants that
grew as weeds or other natural growth on these were used as a treatment.
All crops were disked into the soil during November of each year except
on one series of plots the C. spectabilis was cut, allowed to dry and burned
off before the land was cultivated.
The air-dried material produced by all crops was considerably lower
during 1936 than in 1935, due primarily to the fact that plantings were
made at a later date in 1936. The weight of air-dry material produced
by each treatment in 1935 and 1936 is given in Table 10. Manure at
the rate of 10 tons per acre was added to one series of C. spectabilis plots
and to one series of plots on which the natural growth was considered
the cover crop. The entire area was plowed and kept fallow during the
winter months.

TABLE 10.-YIELD OF COVER CROPS AND OF SUBSEQUENTLY GROWN
VEGETABLES.*
Air-dry ma-
Cover crop trial pounds Beans Peppers Tomatoes
treatment per acre
1935 1936 1936 1937 1936 1937 1936 1937

Cowpeas .............. 5,865 3,489 120 136 117 137 103 112
Velvet Beans ...... 6,925 3,503 139 107 78 88 121 103
C. spectabilis
Immature ...... 6,988 3,612 147 76 79 65 129 90

Soy Beans .......... 5,937 4,440 104 69 61 59 98 89
C. spectabilis
Mature ............ 8,789 2,995 153 141 115 145 125 106
C. intermedia .... 6,680 4,239 123 92 78 86 104 99
Sudan Grass -..... 7,919 3,390 200 102 109 110 123 109
C. spectabilis
Burned ............ 7,433 3,099 189 121 112 71 132 79
Natural growth
plus manure 7,812 4,401 123 92 89 95 112 110
C. spectabilis
plus manure .. 6,675 3,294 147 143 97 109 147 114
Natural growth 6,988 3,430 100 100 100 100 I 100 100


*Yields calculated in percent


of yield obtained on natural growth plots.







Annual Report, 1937


In March beans, peppers and tomatoes were planted on each plot. In
addition to these crops, cucumbers were planted but failed to produce a
satisfactory crop because of injury by cold, wet weather, nematodes and
mildew. The other crops grew well during the present season and the
yield on all treatments was considerably higher than for the previous
season. Yields for the present season indicate that C. spectabilis disked
under when mature or supplemented with manure and cowpeas disked
under when mature is superior to any of the other treatments. The only
decided variation in results between 1936 and 1937 was the relative im-
provement in the yield of crops grown following cowpeas and the very
decided decrease in yield of certain crops grown on plots where the cover
crop of C. spectabilis was burned instead of being disked into the soil
for green-manuring purposes. This was particularly noticeable on crops
such as peppers and tomatoes that have a relatively long growing season.
The yield of all vegetables grown following Sudan grass continued to
be good. The yield of the vegetables produced following each of the
various cover crops is given in Table 10.

TABLE 11.-NITRATES* IN THE SOIL OF INDIVIDUAL COVER CROP
TREATMENTS.

Date of analysis
Treatment 1936 | 1937
July 14 1 Aug. 26 I Oct. 9 I Jan. 41 Feb. 15 IMar. 24

Cowpeas .................... .647 .755 1.286 1.275 1.153 5.250
Velvet Beans .............. .585 .471 .694 1.174 .884 7.876
C. spectabilis
(turned under in
early blossom) ....... .760 .685 .388 1.002 1.050 5.240
Soy Beans ................ .664 .638 .385 .881 .957 8.163
C. spectabilis
(turned under
mature) ................. .556 1.362 .643 .707 .869 6.494
C. intermedia ................ .469 .452 .434 1.052 1.029 6.805
Sudan grass .............. .745 .837 .483 .816 1.094 6.867
Crotalaria spectabilis
(crop burned) .......... .679 2.025 .800 1.182 .612 5.317
Manure (10 tons per
A) plus natural
growth .................... .601 .434 .358 .835 .888 7.867
Manure (10 tons per
acre) and C. specta-
bilis ............................ .695 1.386 .760 1.074 .982 7.437
Natural growth ............ .474 .725 .347 .802 .634 4.615
*Mgs. nitrogen as nitrates per 100 grams air dry soil.

It has been observed that those cover crops that germinate and grow
rapidly prevent and actually decrease the stand of nut grass. Plots on







92 Florida Agricultural Experiment Station

which cowpeas and velvet beans were grown are comparatively free of
nut grass while plots planted to 0. spectabilis, C. intermedia or soybeans
are badly infested.
Nitrate determinations have been measured on the soils of the various
plots at intervals during the year. The results of these analyses are given
in Table 11. From preliminary observations it appears that there is
but slight correlation between the amount of nitrates in the soil and the
yield of the various vegetable crops.

FUMIGATION OF HORTICULTURAL PRODUCTS
State Project 314 R. J. Wilmot
Preliminary work on the use of methyl bromide as a fumigant indicates
that at recommended dosages it is safe to use on tomato and pepper plants
but that it causes injury to eggplants. With basal dosages at the rate
of 2% pounds to 1,000 cubic feet and an exposure of 1% hours, new
potatoes, green beans, tomatoes, peppers, cucumbers, squash, eggplants,
and green corn have been fumigated without injury.
Methyl bromide is capable of penetration into green vegetable material
to a high degree in comparison to HCN. It killed 100% of the pickle
worms (Diaphania nitidalis) in their burrows in cucumbers with one-fourth
the basal dosage while with a basal dosage of HCN there was only 20%
mortality.
FUMIGATION OF NURSERY STOCK
State Project 315 R. J. Wilmot
This project was approved before materials were available, and no
studies on the effects of fumigation on nursery stock could be made.

FUMIGATION OF SEEDS
State Project 316 R. J. Wilmot
No work could be done on the effects of fumigation on seeds, as the
project was approved before materials were available.







Annual Report, 1937


PLANT PATHOLOGY

As a whole, work progressed satisfactorily on the plant disease projects.
Practically all selections of tomatoes planted in Manatee County in the
trials for resistance to Fusarium wilt were drowned by heavy rains after
it was too late to start a new crop; hence practically no progress was
made on that project. Alternate dry and wet weather interfered with
the field trials of watermelon selection for resistance to Fusarium wilt.
A new bacterial wilt and soft rot disease of potatoes appeared in the
Hastings area this year and caused heavy losses in many fields. Indica-
tions are that the disease was introduced in the seed potatoes from Maine.
Bean rust reappeared in epidemic form in the southern part of the
state about the first of January. Work was started on the problem last
year at the Everglades Station and results obtained to date indicate that
the organism may be a new strain.
With financial assistance of the Palmer Farms Growers Cooperative
Association, spraying experiments were conducted in the Sarasota area
for comparing the effectiveness of certain fungicides in the control of
celery pink rot. Laboratory studies of the fungus gave much information
on its physiology.

INVESTIGATIONS RELATIVE TO CERTAIN DISEASES OF
STRAWBERRIES OF IMPORTANCE IN FLORIDA
State Project 126 A. N. Brooks
Strawberry Laboratory
Spraying experiments were started in strawberry beds to compare the
effectiveness of several copper salts, combined with different wetting
agents, in the control of runner spot and other foliage diseases. Data
for this year's tests will not be available until this fall when the plants
are removed from the nurseries for setting in the fields.

STUDIES RELATIVE TO DISEASE CONTROL OF WHITE
(IRISH) POTATOES
State Project 130 A. H. Eddins
Potato Disease Laboratory
Every year weather conditions become especially favorable for the
development of potato diseases in one or more of the potato growing
sections of the state. Such conditions existed at Hastings in 1937 when
the seed-borne diseases, late blight, bacterial wilt and soft rot caused by
Bacillus carotovorus, and blackleg caused a loss estimated at one million
dollars.
Despite the good care taken of the seed after its arrival in Florida
and the regular application of copper-lime dust to the growing crop,
stands were reduced by 10 to 60 percent in hundreds of acres planted
with certified seed severely infected with late blight. This disease caused
a rotting of the seed pieces, killed the sprouts and plants and caused a
high percentage of decay in the new tubers.
Wet weather during the first half of April also favored the develop-
ment of blackleg and bacterial wilt and soft rot which ruined the market-
ability of thousands of barrels of potatoes.
Losses caused by planting certified seed which carried a high percentage
of late blight rot, bacterial wilt and soft rot and blackleg proved that
such seed was unfit for planting and that the present certification require-
ments do not insure the delivery of seed which will produce crops reason-







Florida Agricultural Experiment Station


ably free of these diseases under conditions similar to those which existed
at Hastings in 1937.




















Fig. 5.-New Potato Disease Laboratory building at Hastings.

Forty-one different varieties and variety crosses, most of which were
supplied by the USDA, were grown in experimental plots. Most of the
new variety crosses were resistant to late blight and, with few exceptions,
produced better yields than the Spaulding Rose. Nine yielded over 100
barrels of marketable tubers per acre, approximately twice the yield of
the Spaulding Rose, and five of these were entirely free of soft rot and
blackleg as well as late blight rot. Several of the new varieties will be
grown again next year in different localities throughout the Hastings
section.

INVESTIGATIONS AND CONTROL OF BROWN ROT OF POTATOES
AND CLOSELY RELATED CROPS CAUSED BY
Bacterium solanacearum E. F. S.
State Project 143 A. H. Eddins
Potato Disease Laboratory
Sub-normal temperatures in March and heavy rains during the first
10 days of April followed by a severe epidemic of late blight which caused
the potato crop to die prematurely were unfavorable for the development
of brown rot. The latter disease caused a loss of only 1 percent as
compared with the five-year average loss of 2.2 percent for the Hastings
section.
Plots on Scranton fine sand given the sulfur-limestone treatment in
1934 and those on Bladen fine sandy loam treated in 1935 gave approxi-
mately the same yield of potatoes in 1937 as the nontreated plots. No
brown rot developed in the treated plots, or in the nontreated plots on
Bladen fine sandy loam and only 0.2 percent of the tubers were affected in
the nontreated Scranton fine sand.
Results obtained from soil treatments made in the summer of 1936
indicated that the initial reaction of the soil could be used as a basis
for calculating the amount of sulfur required to produce reactions lethal







Annual Report, 1937


to Bacterium solanacearum. For example, complete control of brown rot
was obtained and normal yields were maintained in Scranton fine sand
and Bladen fine sandy loam by treatment with sufficient sulfur to estab-
lish lethal reactions of pH 4.2 and lower followed by sufficient limestone
to readjust the reaction to that of untreated soil. Tuber infection in the
adjacent nontreated plots was 3.0 percent. When 400 pounds and 600
pounds of sulfur per acre were used on Scranton fine sand, the reactions
of the upper six inches were changed pH 0.5 and pH 1.2, respectively;
and when similar amounts were used on Bladen fine sandy loam, the
changes were pH 0.8 and pH 1.3, respectively. When commercial flour
sulfur and inoculated sulfur were each applied at rates of 600 pounds
and 800 pounds per acre to Bladen fine sand, Bladen fine sandy loam
and Scranton fine sand, approximately the same changes occurred in the
pH values of these soils. The most acid reactions developed in the upper
3 inches, and the minimum reactions were established in the upper six
inches within two months after treatment, after which the soils became
naturally adjusted to more alkaline reactions. After the completion of
tests now in progress, the data obtained should serve as a basis for
recommending the amount of sulfur needed to control brown rot in different
soil types with different initial reactions and the amount of limestone
needed to readjust the reactions for normal yields.
Seven varieties, variety crosses and numbered seedlings out of a total
of 41 supplied by the United States Department of Agriculture either
escaped infection or were immune to infection from Bacterium solanacearum
when grown in infested soil in each of two fields. Weather conditions
were very unfavorable for the development of brown rot, and tuber in-
fection in the most susceptible variety was only 2.2 percent in one field
and 24.1 percent in the other. No brown rot developed in Golden, Aker-
segen, K87, 053, 055, 0184 and N. C. No. 1, while Warba, 336-31, 336-11,
Chippewa and CS 110 were the most susceptible.

A COMPARATIVE STUDY OF FORMS OF DIPLODIA RESEMBLING
Diplodia frumenti
State Project 146 R. K. Voorhees
Work has been concentrated on a comparative study of Diplodia isolates
from several economic hosts to determine their morphologic relationship
to Diplodia frumenti occurring on corn. Isolates also have been made
from other hosts and are being carried in culture and may be included in
this study at a later date. Single spore isolates from different collections
of Diplodia from the same host and from different hosts were paired in
culture in all possible combinations. In practically every case the different
isolates showed aversion to each other, thus indicating they were all dif-
ferent strains. Other morphological studies indicate that some of the
isolates may even vary enough from the D. frumenti type to be considered
as different species. Several single spore cultures from the same specimen
of Diplodia from different hosts were paired in culture in all possible
combinations. In some cases none of the isolates from a single specimen
showed aversion to each other; in other cases one or more of the isolates
from a single specimen appeared to be different, thus indicating that
the spores produced on any one specimen may or may not be of the
same strain.
Attempts to produce the ascigerous stage of the various Diplodia isolates
in culture and on host material have been unsuccessful thus far. Neither
has this stage been found in Nature on any of the various hosts. The
Physalospora stage which has been collected on the various hosts and






96 Florida Agricultural Experiment Station

cultured to date has in practically every case yielded pycnospores of the
Sphaeropsis type instead of the Diplodia type.

INVESTIGATIONS OF DISEASES OF FERNS AND ORNAMENTALS
State Project 148 W. B. Shippy
Watermelon Laboratory
Further tests were made of a new spray preparation for use on orna-
mentals and other plants. This is prepared from copper sulfate, soap
and ammonia and has been described under the name "Flordo".
Additional tests were made to determine a preferable timing of the
cool storage period and to determine the effect of prolonged exposure of
Easter lily bulbs to cool storage. One month of cool storage was applied
during three periods: August 20 to September 20, September 5 to October 5,
and September 20 to October 16. The first period had almost no effect
on hastening flowering. The second period resulted in 32 percent flowers
in January, 39 percent in February and 26 percent in April. The third
resulted in 75 percent flowers in February and 25 percent in March. These
results further emphasize the importance of applying cool storage late
in the rest period. For cool storage periods beginning during late August
(August 20) it was found that storage of two months or more was detri-
mental, resulting in smaller plants and fewer flowers.

INVESTIGATION OF AND CONTROL OF FUSARIUM WILT,
A FUNGOUS DISEASE OF WATERMELONS
CAUSED BY Fusarium niveum M. N. Walker
State Project 150 M.N. Walker
Watermelon Laboratory
In spite-of difficulties in securing a stand early in the season, the 1936
experimental plantings came through very well and 746 melons were
harvested for seed. Of this number, 674 were artificially self-pollinated,
most of which were of the "Leesburg" variety. Conditions for wilt infec-
tion were favorable throughout the season and a good test of resistance
of the strains under trial was obtained. Practically all strains now main-
tained for trial have shown high resistance. Although degree of resistance
varied, all strains were more resistant to Fusarium wilt than the Watson
checks, of which only three plants out of about 1,500 survived to produce
melons. Only one of these was apparently free from infection, but the
results of the field trials in 1937 indicate that this plant had only escaped
infection.
Reports from growers who had received small lots of seed of the
1935 crop indicated that the Leesburg variety stands up well as far as
wilt is concerned, but the average size of the melons is in general some-
what smaller than the Watson. Trials were carried out in a number of
places in Florida as well as in other states.
Because of the failure to secure sets on most of the crosses made
in the spring, 21 individual melon selections were planted in July for
crossing. In September 56 cross-pollinated melons were harvested, and
seed from the best ones were planted in the greenhouse in early November.
Forty F, melons were harvested from these plants, but too late for the
regular field planting in 1937. Although some of these F. seed were
planted later it is doubtful whether any melons will be harvested. Some
of the F1 seed were planted in the field in 1937 and the progeny showed
a great deal of promise. It is hoped that a field of sufficient size may
be planted in 1938 to seed of these F, melons to allow for the isolation
of desirable segregants.






Annual Report, 1937 97

Approximately 60 pounds of seed of the Leesburg stock were distributed
for trials during the spring of 1937. One 10-acre field, portions of which
had been in melons for three and four years, was planted near Leesburg
and, although planted somewhat late, did very well and furnished the
first car-lot shipment of the Leesburg variety. From general observations
of the 1937 plantings, it appears that most of the melon-lot strains of
the Leesburg variety are somewhat short as compared to the standard
Watson variety, but certain strains have shown good length and efforts
are being made to further isolate and multiply this type. Some crosses
towards this end also have been made.
Replicate plantings were made in the spring of 1937 from 45 melon
seed-lots of best strains of the Leesburg variety harvested during 1936.
In addition to these, approximately 165 melon-lot strains of other types
of melons were planted.
Artificial pollination during the 1937 season was hampered by dry
weather and lack of pollination equipment. Because of this only about
350 artificially pollinated melons will be harvested this year, which is
not a sufficient number to allow for the proper selection. It will be neces-
sary to have some open-pollinated melons to avoid the total loss of some
of the strains.

INVESTIGATION OF AND CONTROL OF FUNGOUS DISEASES
OF WATERMELONS
State Project 151 M. N. Walker
Watermelon Laboratory
As a result of the repeated growing of melons on the same land a
number of new problems have arisen, all of which probably cannot be
properly considered as pathological. Certain variations in seed germina-
tion and early growth of watermelon plants have been especially difficult
to explain. The occurrence of secondary organisms may account for some
of the variations, and it is also possible that fluctuations in the degree
of infestation by the wilt organism under different methods of land
management may present explanations. Plans are being made to con-
duct tests next year in an effort to explain some of the variations that
have occurred.
Because of favorable weather conditions, anthracnose has taken a heavy
toll in the commercial fields this year. Because of the short crop and
the continued demand, melons that normally would be culled are being
shipped at a fairly good price.
No consistent preventive measures against anthracnose are employed
by any of the larger growers, in spite of the fact that work in the experi-
mental field has indicated that injuries from the disease can be greatly
reduced by seed treatment, the avoidance of excessively early planting,
thorough spraying or dusting of young vines, and by avoiding as far as
possible contact, in the processes of thinning and harvesting, with the vines
when they are wet. There have been some indications in the experimental
field that susceptibility to anthracnose is sufficiently variable among strains
and varieties to permit the isolation of strains much more resistant than
the commercial sorts. Trials are being made of such varieties developed
by the Iowa Experiment Station. However, it will be necessary to carry
on the wilt work and the anthracnose work in different fields to avoid
undue complications in some years.






Florida Agricultural Experiment Station


No further reports of the trouble on the variety Cuban Queen, de-
scribed in last year's report, have been received.

A STUDY OF THE SO-CALLED "RUST" OF ASPARAGUS PLUMOSUS
State Project 167 W. B. Shippy
Watermelon Laboratory
An intensive study of the blight disease (rust) was made from August
15 to October 15, 1936, in a commercial fernery which has been particularly
subject to the disease during recent years. Blight appeared suddenly on
September 16, being confined almost entirely to an area of the fernery
where no fungicide had been applied. Soft growth approaching the fully
expanded stage was chiefly affected, and the injured portions of individual
sprays consisted variously of single branchlets, patches of small or large
size, and sometimes the entire spray. Injured areas first turned yellow,
then light brown, and soon the branchlets dropped off, leaving only the
denuded stems. During the following two weeks an abundance of new
growth developed in the fernery, but there was no evidence of new in-
fection until on October 5, when the second outbreak of blight appeared
suddenly and more extensively.
A species of the fungus Helminthosporiwm, was prominently associated
with the disease during both outbreaks. The fungus produced few spores
in culture, but sporulated abundantly on pieces of cultures pressed onto
the foliage of plumosus plants that were held in a moist chamber for
several days and then returned to the greenhouse. When these spores
were atomized or dusted over healthy plants infection resulted in every
instance. This organism appears to be the same fungus studied in 1931,
the cultures of which at that time proved only temporarily infectious. It
at least accounts in part for plumosus blight, and experiments have been
started to determine more exactly the relationship and methods of control.
No correlation was noted between the occurrence of blight and weather
conditions or water content of the soil.

CONTROL OF WILT OF TOMATOES (Fusarium lycopersici Sace.)
IN FLORIDA
Hatch Project 180 George F. Weber and D. G. A. Kelbert
Tomato Disease Laboratory
Since the report of a year ago the tomato hybrids have been grown
through two more generations, during which time a number of them have
been eliminated because of undesirable vegetative characters or because
they did not prove sufficiently resistant to survive when grown on Fusarium-
sick soil. Forty new crosses have been made and seed has been collected
from certain hybrids growing on sick soil to be used in further trial
plantings.
Plantings of some of the most promising selections of crosses were
made this year on Fusarium-sick soil in the Manatee County sections to
obtain comparative yield data. Heavy rains during the first two weeks
of April killed a large portion of the plants, and made it impossible to
obtain this information.
The trials will be continued next season to propagate the crosses made
this season, for further tests of F2, F3 and F4 selections on Fusarium-sick
soil and for comparative yield data of several of the most promising
hybrids and commercial varieties.




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