• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Letter of transmittal
 Credits
 Frontispiece
 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/UF00027385/00021
 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: 1935
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: VID00021
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltuf - AMF8114
oclc - 12029671
alephbibnum - 002452809
lccn - sf 91090332
 Related Items
Preceded by: Report for the fiscal year ending June 30th ...
Succeeded by: Annual research report of the Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida

Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Title Page
        Page 1
    Letter of transmittal
        Page 2
    Credits
        Page 3
    Frontispiece
        Page 4
    Main
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    Index
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        Page vi
        Page vii
        Page viii
Full Text













UNIVERSITY OF FLORIDA
GAINESVILLE, FLORIDA



AGRICULTURAL EXPERIMENT

STATION





Annual Report
FOR THE FISCAL YEAR ENDING
June 30, 1935


L IM













LIST OF DEPARTMENT REPORTS


Report of the Director ....... .. ....... ..- .... ....
Report of Business Manager... ................. .... ............
Publications, N ews, Radio ................. .............. ...... ....... ..........
The Library ................... .. .. ........... ..............................
Agricultural Economics ......................................
A gronom y .......... ........ .......... .............. ....
Animal Husbandry.......... ................... ...............
Chem istry and Soils....- ........ ..... .... ....... ........... ..... .....
E ntom ology............................................ . ...........................
H om e Econom ics................. .. ......... ... ............
H orticulture ...... .. .. .... ...... ..................... .................. .....
Plant Pathology ............. .... ............ .............
Citrus Experiment Station.............. ... ...................
Everglades Experiment Station-........ ......................................
North Florida Experiment Station.. ............................... ........
Sub-Tropical Experiment Station.. ...... .......... ..............
West Central Florida Experiment Station.. ..............................


Page
.. ...... .. 5
...... ... .... ......... 15
............................. 22
...... ................... .. 3 0

.............................. 36
.......... ...... 4831
.................. .... .... 6 0
48
60
................ 64
................... 70
74
... ...... ... 85
96
101
........... ................ 13 2
140
149


Hon. Dave Sholtz,
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, 1935.
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, 1935, and I request that you transmit
the same, in accordance with law, to His Excellency, the Governor of
Florida.
Respectfully,
JOHN J. TIGERT,
President, University of Florida.










EXECUTIVE STAFF

John J. Tigert, M.A., LL.D., President of
the University
Wilmon Newell, D.Sc., Director
H. Harold Hume, M.S., Asst. Dir., Research
Harold Mowry, M.S.A., Asst. Dir., Adm.
J. Francis Cooper, M.S.A., Editor
Clyde Beale, A.B.J., Assistant Editor
Jefferson Thomas, 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

ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Animal Husbandman**
R. B. Becker, Ph.D., Dairy Husbandman
W. M. Neal, Ph.D., Associate in Animal
Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Asst. Veterinarian
W. W. Henley, B.S.A., Assistant Animal
Husbandman
P. T. Dix Arnold, B.S.A., Assistant Dairy
Husbandman

CHEMISTRY AND SOILS
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
H. W. Jones, M.S., 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**
L. W. Gaddum, Ph.D., Biochemist
C. F. Ahmann, Ph.D., Physiologist
J. T. Hall, Jr., B.S.Ch.E., Asst. Physiologist

ENTOMOLOGY
J. R. Watson, A.M., Entomologist**
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
J. W. Kea, B.S.A., Assistant

HORTICULTURE
A. F. Camp, Ph.D., Horticulturist**
G. H. Blackmon, M.S.A., Horticulturist
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

*In cooperation with U.S.D.A.
** Head of Department.


BOARD OF CONTROL

Geo. H. Baldwin. Chairman, Jacksonville
A. H. Blanding, Bartow
Oliver J. Semmes, Pensacola
Harry C. Duncan, Tavares
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
R. M. Crown, B.S.A., Asst. Agronomist
Jesse Reeves, Farm Superintendent

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

EVERGLADES STATION, BELLE GLADE
A. Daane, Ph.D., Agronomist in Charge
R. N. Lobdell, M.S., Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
G. R. Townsend, Ph.D., Assistant Plant
Pathologist
J. R. Neller, Ph.D., Biochemist
R. W. Kidder, BS., Assistant Animal
Husbandman
Ross E. Robertson, B.S., Assistant Chemist
SUB-TROPICAL STATION, HOMESTEAD
H. S. Wolfe, Ph.D., Horticulturist in Charge
W. M. Fifield, M.S., Asst. Horticulturist
Stacy O. Hawkins, M.A., Assistant Plant
Pathologist

WEST CENTRAL FLORIDA STATION,
BROOKSVILLE
E. W. Sheets, D.Agri., Animal Husbandman
in Charge*
W. F. Ward, M.S.A., Asst. An. Husbandman*


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
R. E. Nolen, M.S.A., Asst. Plant Pathologist

Cocoa
A'. S. Rhoads, Ph.D., Plant Pathologist

Hastings
A. H. Eddins, Ph.D., Plant Pathologist

Monticello
G. B. Fairchild, M.S., Assistant Entomologist

Bradenton
David G. Kelbert, Asst. Plant Pathologist

Sanford
E. R. Purvis, Ph.D., Assistant Chemist,
Celery Investigations




























Fig. 1.-This barn, 50 x 104 feet, was constructed during the year for
steer feeding experiments at the North Florida Experiment Station.


Fig. 2.-The recently constructed tobacco curing barn at the North
Florida Experiment Station, with open bottom and top ventilators, provides
needed facilities.










Report for the Fiscal Year Ending

June 30, 1935




Hon. John J. Tigert,
President, University of Florida.
Sin: 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, 1935.
Respectfully,
WILMON NEWELL,
Director.

INTRODUCTION
Presented herewith is a resume of the work and progress of the Agri-
cultural Experiment Stations for the fiscal year ending June 30, 1935.
The year has been one of gainful productivity. Substantial progress
has been made in all lines of investigation under way and notable results
have been attained in several instances. In addition to normal Station
activities it has been necessary to undertake many emergency responsibili-
ties as a part in cooperating with agencies of the Federal Government in
enterprises directed toward agricultural recovery and the general improve-
ment in agricultural conditions. These have been carried willingly and
as effectively as possible but with some sacrifice to the projected program
of research.
The work of all departments housed in the Experiment Station was
seriously disrupted early in the fiscal year for a period of about two months
when the building was condemned and evacuated pending the strengthening
of major structural weaknesses and the installation of new electric wiring
throughout. Although the building has been adjudged safe for reoccupancy,
the repairs made can be considered as only temporary in nature.
The eight major departmental lines of investigation have been main-
tained as have also the four branch stations and seven field laboratories.
Detailed reports on the work of each will be found under their respective
headings.
ORGANIZATION AND FUNCTION
The Agricultural Experiment Station, the research division of the College
of Agriculture, is charged with the responsibility of discovering solutions
to the basic, complicated and constantly changing problems of Florida's
diverse agriculture. It was established, under the Federal Hatch Act, in
1887 at Lake City, and removed in 1906 to Gainesville following the passage
of the Buckman Act which consolidated several other state institutions
of higher learning with the University of Florida. The Station serves
in a dual capacity as the State's agricultural research organization and as
an integral part of the Experiment Station system of the United States
Department of Agriculture.
Advancement of the State's agriculture has been and is intimately
associated with, and dependent upon, agricultural research. The total








Florida Agricultural Experiment Station


annual production of agricultural products of the state is estimated to
have a valuation of $100,000,000 to $125,000,000. In the attainment of this
production, the Experiment Station in its 47 years of continuous service
has played no small part; it has introduced new crops and bred new va-
rieties, worked out efficient cultural and soil management methods, shown
kinds and amounts of fertilizers and uncommon elements of economic
worth for various crops, has devised methods and means of protection
against diseases and insect pests, has been of major help in the develop-
ment and protection of the livestock industry, has studied and advised
as to economic trends and management. In short, it has been and is the
impartial and unbiased agency to which the farmer, fruit grower, poultry-
man and stockman of Florida look for the solving of the seemingly endless
problems confronting them.
Florida, with its sub-tropical climate, complexity of soils and wide
diversity of agricultural activities, presents a set of agricultural problems
distinctly different from those of most other states. Of necessity, the scope
of investigational work of the Station has increased and widened as the
problems of agriculture have grown in number and complexity, particularly
with changing economic conditions. To meet the pressing and definite
need for specialized research on these problems, the Experiment Station
as now organized consists of the Main Station at Gainesville, four branch
stations, and seven field laboratories. The branch stations are located at
Lake Alfred, in Polk County; Quincy, in Gadsden County; Belle Glade, in
Palm Beach County; and Homestead, in Dade County. Field laboratories
are located at Bradenton, Plant City, Cocoa, Leesburg, Monticello, Hastings,
and Sanford. The sub-stations and field laboratories are not separate and
isolated institutions; they are units comprising the Florida Experiment
Station System and are under the direct administration of- the Main Station
at Gainesville.
Departments or divisions of research include Agronomy, Animal Hus-
bandry and Veterinary Science, Entomology, Chemistry and Soils, Horti-
culture, Plant Pathology, Agricultural Economics, and Home Economics,
and are staffed by scientists trained in those fields. At the Main Station
the scope of investigations covers almost the entire agricultural field insofar
as facilities will permit; at the branch stations the work is confined to
general problems of their areas; and at the field laboratories the scope
is restricted mainly to insect or disease problems of specific crops. The
number of active projects, of which there are more than 150 spread over
the field of Florida's agriculture, is indicative of the breadth of the research
program.
At Lake Alfred the work of the Citrus Station is confined to problems
of citrus production-culture, fertilizers, rootstocks, new varieties, bud
selection, cover crops, and disease and insect control.
The sub-station at Quincy was established primarily for the investiga-
tion of tobacco diseases and as a result of its work the major disease of
the shade tobacco area has been overcome. The scope of work recently
has been enlarged to include the general agricultural field as it pertains
to northwestern Florida.
With the opening of the Everglades the immediate and urgent need
of research on the saw-grass peats and mucks became strikingly evident
with the failure of numerous crops on the apparently fertile soils of that
region. Findings of workers at the Everglades sub-station have shown
the cause and means of prevention of many of these failures. In spite
of several handicaps, investigational work has progressed steadily; new
crops are being successfully introduced; the way is being shown for cattle
production; drainage and water table studies are daily proving of worth;


L








Annual Report, 1935


and, in short, the many problems of that region are being intensively
studied and one by one successfully solved.
The Sub-Tropical Station, the infant of the branch stations, is now
in its fifth year. It has for its work the field of tropical and sub-tropical
fruits and the problems connected with the production of winter vegetable
crops on the calcareous and marl soils of the lower East Coast.
A field laboratory has been established at Cocoa to investigate diseases
of citrus, principally the so-called "gum" diseases and mushroom root rot.
Strawberry diseases and methods of control are studied at the Plant City
laboratory, and diseases of tomatoes, with special attention to tomato
wilt, are under investigation at the Bradenton laboratory.
At Leesburg the devastating disease of watermelons, watermelon wilt,
which necessitates clearing new lands annually that a crop may be pro-
duced, is being worked on intensively and successfully. Diseases and
insects affecting commercial ornamental plants, and control of rodents
affecting farm crops are also under investigation here.
Potato growers are given aid in the control of Irish potato diseases
at the Hastings laboratory. Diseases are identified and control measures
devised and demonstrated.
At Monticello, the work of the laboratory is confined to the control of
insects affecting the pecan, and at Sanford troubles of a soils or fertilizer
nature that have developed in celery plantings are being investigated.
Investigational work with beef cattle, poultry, pasture grasses and
forage crops is carried cooperatively at the U. S. D. A. West Central
Florida Experiment Station, Chinsegut Hill, near Brooksville. Several
projects in the fields of chemistry and soils, horticulture, animal husbandry,
agricultural economics, agricultural engineering, and agronomy are carried
at other points in the state in cooperation with different bureaus of the
United States Department of Agriculture.
DONATIONS
Under date of February 23, 1935, a tract of 40 acres (SEa of SW14
Section 16, Township 27S, Range 26E) of uncleared citrus lands was donated
to the Citrus Experiment Station by the Florida Agricultural Research
Institute. This additional and much needed acreage will be of material
aid in the enlargement of field investigations in citrus research.
A purebred Brahma bull, Sir Selim 2nd., was added to the Station herds
in April. This bull was donated by Mr. J. D. Hudgins, of Hungerford, Texas.
FINANCIAL RESOURCES
Financial resources of the Experiment Stations for the fiscal year ending
June 30, 1935, including balances carried forward from the previous year,
were as follows:
Federal Adams Fund ........... .. ---...... .. ....... $ 15,000.00
Federal Hatch Fund...----.............----.. ........... ......... ........... 15,000.00
Sate Funds
M ain Station ..... .............................................................. ................ 217,479.15
Including Field Laboratories as follows:
Tomato Disease Investigations, Bradenton .......$2,940.49
Strawberry Investigations, Plant City............... 6,405.14
Citrus Disease Investigations, Cocoa.................. 3,500.93
Potato Disease Investigations, Hastings............. 5,359.89
Pecan Insect Investigations, Monticello..... ....... 2,915.16
Celery Investigations, Sanford .......--....--...... 6,680.52
Fumigation Research............-................... 3,774.25
Grape Pest Investigations .................... .... .. 3,571.90








8 Florida Agricultural Experiment Station

Citrus Experiment Station, Lake Alfred........................................ 11,548.90
Everglades Experiment Station, Belle Glade................................ 50,376.36
North Florida Experiment Station, Quincy.................................... 20,986.32
Sub-Tropical Experiment Station, Homestead............................... 10,596.71
Watermelon Investigations Laboratory, Leesburg........................ 6,246.63
Incidental Funds, Sales, etc-..................................--------.. 37,504.21

$384,738.28
Federal Funds, not included above.....-....................-------- ..--.$ 60,000.00

CHANGES IN STAFF
Changes as follows took place in the Station staff during the year:
Miss Lillian Arnold was appointed Assistant Botanist, July 1, 1934.
Alvin H. Spurlock was appointed Assistant Agricultural Economist,
July 1, 1934.
J. W. Kea was appointed Assistant Entomologist, July 1, 1934, and
granted leave of absence to the State Plant Board, March 9, 1935.
J. T. Hall, Jr. was temporarily appointed Assistant Physiologist, July
1, 1934.
Jefferson Thomas was appointed Assistant Editor, July 1, 1934.
F. S. Jamison was appointed Truck Horticulturist, August 9, 1934.
G. B. Fairchild was appointed Assistant Entomologist, September 1, 1934.
C. C. Goff, Assistant Entomologist, was granted leave of absence from
October 15, 1934, to June 30, 1935, to pursue graduate studies.
R. V. Allison, Soils Specialist in charge Everglades Station, was granted
a second year's leave of absence on November 15, 1934 to continue work
with the U. S. Department of Agriculture in soil erosion investigations.
B. A. Bourne, Plant Physiologist, Everglades Experiment Station, re-
signed December 16, 1934.
H. W. Jones was granted six months' leave of absence, beginning January
1, 1935, to aid in soil erosion investigations with the U. S. Department
of Agriculture.
R. B. French was appointed Associate Chemist, January 3, 1935.
C. F. Ahmann, Physiologist, was granted leave of absence from February
1 to June 30, for further pursuit of graduate studies.

SCOPE OF INVESTIGATIONAL WORK
July 1, 1934-June 30, 1935
The projected lines of research of the Agricultural Experiment Stations
for the fiscal year, arranged according to departmental classification and
with page reference to a discussion of each project, are listed on the fol-
lowing six pages.




Department Number Title Page


AGRICULTURAL
ECONOMICS







AGRONOMY













ANIMAL
HUSBANDRY


Agricultural Survey of Some 500 Farms in the General Farming Region of North-
w est F lorida......................................................... .........................................................
Farmers' Cooperative Associations in Florida......................... ....... ...........................
Cost of Production and Grove Organization Studies of Florida Citrus..................
A Study of Pre-Cooling and of Refrigeration in Transit as Affecting Cost of
Marketing, Quality and Price of Citrus Fruits........ ........................
Farm Taxation........ ..............................................................
A Study of Adjustments in Farming by Regions and Type-of-Farming Areas,
from the Standpoint of Agricultural Adjustment and Planning, Including
Soil Conservation ...... ........... .. .... ....................... ..
Plant Breeding-Peanuts ...................................... ........... ....
Pasture Experiments...... ............................. ..............
Crop Rotation Studies with Corn, Cotton, Crotalaria and Austrian Peas..............
Variety Test W ork with Field Crops............................ .......................... ......
Green Manure Studies................................. .... ........... ........ .....
Improvement of Corn Through Selection and Breeding............................
Crop Adaptation Studies....................................................
Fertilization of Pasture and Forage Grasses....... .............................
Date of Seeding and Phosphate Requirements of Winter Legumes and Their
Effect Upon Subsequent Crops.................................................................. ....
Ratio of Organic to Inorganic Nitrogen in Mixed Fertilizer for Cotton-..-........-
Corn Fertilizer Experiments.................................................... ...........
A Study of Crotalaria as a Forage Crop................................................ ...........
A Study of "Chlorosis" in Corn Plants and Other Field Crop Plants..................
A Study of the Development and Deterioration of Roots in Relation to the Growth
of Pasture Plants Grown Under Different Fertilizer and Cutting Treatments
The Etiology of Neurolymphomatosis gallinarum (Fowl Paralysis) .....................
Deficiencies in Feeds Used in Cattle Rations..................................
Comparison of Various Grazing Crops with Dry Lot Feeding for Pork Production
Relation of Conformation and Anatomy of the Dairy Cow to Her Milk and Butter
Fat Production ..................................................................................... ......................
Fattening Fall Pigs for Spring Market....................................................... ..
A Study of Feeding Value of Crotalarias..........................................
Swine Field Experiment (Sanitation)............................................. ...
The Determination of Digestibility Coefficients for Crotalaria Hay...............
The Effect of Feeding Crotalaria Seed to Chickens and Other Birds ..................








Department
ANIMAL
HUSBANDRY
(Continued)
















CHEMISTRY
AND SOILS









ENTOMOLOGY


Number
213
215
216
217
218
219
236
239

241

244
245

246
250

251
258
22

37

67
94
95
96
220
223
240
252
8
12
13


Title Page
A Study of the Ensilability of Florida Forage Crops.......................................... 53
Beef Cattle Breeding Investigations. ............... ...... .............. ....................................... 53
Cooperative Field Studies with Beef and Dual-Purpose Cattle................................... 54
Dual-Purpose Cattle Investigation Under Farm Conditions................---- ............... 54
Factors Affecting the Percentage of Calf Crop and Size of Calves.....................----..... 54
Beef and Dual-Purpose Cattle Investigations................ .................................... 55
Investigations of Hemorrhagic Septicemia in Cattle and Swine....-------........................... 55
The Digestibility Coefficients and Feeding Value of Dried Grapefruit and Dried
Orange Refuse-.............. ...... .... ... ......... ......... ............ 56
Efficiency of the Trench Silo for the Preservation of Forage Crops, as Measured
by Chemical Means and by the Utilization of the Nutrients of the Silage by
battle ................................... ............ .... ............... ...... ................... 56
A Comparative Study of Corn and Liquid Milk vs. a Grain and Mash Ration in
Feeding for Egg Production......................................................................................... 57
A Comparative Study of the Value of Meat Scraps, Fish Meal and Milk Solids as
Sources of Protein for Egg Production.................................................................... 57
Lights vs. No Lights for Egg Production.......................................................................... 57
Effect of Feeding Colon Organisms and Dried Whey on the Bacterial Flora of
Baby Chicks Affected with Pullorum Disease............................................................ 58
The Etiology of Leukemia in the Domestic Fowl............................................................ 58
A Study of Plants Poisonous to Livestock in Florida.................................................... 59
Determination of the Effect of Varying Amounts of Potash on the Composition
and Yield and Quality of the Crop.......................................................... ........ .. 60
Determination of the Effect of Various Potash Carriers on Growth, Yield and
Com position of Crops............................. ....... ......... .. .. 60
Composition of Crops as Influenced by Fertilization and Soil Types-Pecans.......... 60
Effect of Various Fertilizer Formulas....... .................... .... .......... 61
Concentrated Fertilizer Studies.......................................................................................... 61
Determination of the Effect of Green Manures on Composition of Soil........................ 61
A Study of "Chlorosis" in Corn Plants and Other Field Crop Plants-....................... 62
Bronzing or Copper Leaf of Citrus.............................................................................. 62
The Occurrence and Behavior of Less Abundant Elements in Soils............................ 63
Soil and Fertilizer Studies with Celery...................... ...........- .................... 63
The Florida Flow er Thrips.......................... ........... ........................................... ...... 64
R oot K not Investigations....................................................................................................... 64
Introduction and Propagation of Beneficial Insects........................................................ 65




Department
ENTOMOLOGY
(Continued)









HOME ECONOMICS












HORTICULTURE


Number
14
28
60
82
157
162
214
230
231
232
233
234


Title


I


The Larger Plant Bugs................. ... .... ................................ .............. .............
Bean Jassid Investigations............................................................... .......................
The Green Citrus A phid.................................... ....................................... ........ ..... ......
Control of Fruit and Nut Crop Insects-Insects Affecting Pecan Trees....................
Control of Scale-Insects on Woody Ornamentals ............. ............................
Insect and Other Animal Pests of Watermelons............ ...... ..............
Biology and Control of Field Mice in Watermelon Plantings....................................
The Asparagus Caterpillar (Laphygma exigua)............... ................... ......
The Onion Thrips (Thrips tabaci Lindm.) ...--....-....-.........--- --........................-- .
The Gladiolus Thrips (Taeniothrips gladioli M. & S.) ........... -........-...... .............
Control of Purple Scale and Whiteflies with Lime-Sulfur................. .............
Biology and Control of Florida Aphids.-.........----- ...------.......-------........--


142 Relation of Growth to Phosphorus, Calcium and Lipin Metabolism as Influenced
by the Thymus....... ............ .... ................ ....... ......................... ............ .....
198 A Study of Lecithin Synthesis in Hens on a Vitamin A and Lipoid Free Diet........
199 A Study of the Changes which Occur in the Hematopoietic Tissues of Rats on a
V itam in A Free Diet............................................................... ...................................
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...........
222 A Study of the Pathologic Changes in Tissues and Organs of Animals Affected by
Deficiency Diseases or by Toxic Substances................................-...........
255 An Investigation of Human Dietary Deficiency in Alachua County, Florida, with
Special Reference to Nutritional Anemia in Relation to the Composition of
Home Grown Foods........................ .. ........... .....
256 The Development of Quantitative Spectrographic Methods in Agricultural Research

46 Variety Response of Pecans to Different Soil Types, Localities, etc......----..........
47 Cooperative Fertilizer Tests in Pecan Orchards.-......-----.. ..........-........
48 Variety and Stock Tests of Pecan and Walnut Trees.......... .................... ....
50 Propagation, Planting and Fertilizing Tests with Tung-Oil Tree...-..............
52 Testing of Native and Introduced Shrubs and Ornamentals and Methods for Their
Propagation ...................... ............... .. ........ .....
80 Cooperative Cover Crop Tests in Pecan Orchards............ ..................
110 Phenological Studies on Truck Crops in Florida.............................
111 Fundamental Physiology of Fruit Production................ ..... .................


'age
65
66
66
66
67
67
67
67
67
68
68
68

70
70

70

71
71
71









Department
HORTICULTURE
(Continued)






PLANT PATHOLOGY


Number Title Page
165 Relation of Nitrogen Absorption and Storage to Growth and Reproduction in Citrus
and Pecans.... ............................................................................................................ 80
187 Variety Tests of Minor Fruits and Ornamentals..............................-.....................-..... 80
189 Study on the Preservation of Citrus Juices and Pulps................................................ 81
190 Cold Storage Studies on Citrus Fruits................................................................................ 81
237 Citrus M maturity Studies.......................................................................................................... 83
238 Studies on the Effect of Zinc and Other Unusual Mineral Supplements on the
Growth of Horticultural Crops..................................................... ........................... 83
N one Fum igation Research....................................................... ..................................................... 84
19 Downy M ildew of Cucurbits................................ .. .............................................. .. 86
126 Investigations Relative to Certain Diseases of Strawberries of Importance in
F lorida ................................................................................................................................ 86
130 Studies Relative to Disease Control of White (Irish) Potatoes.................................... 86
143 Investigation of and Control of Brown Rot of Potatoes and Closely Related Plants
Caused by Bacterium solanacearum,............................................................................. 87
145 Investigation and Control of a Disease of Corn Caused by Physoderma Zeae-Maydis 89
146 Investigations of Seedling, Stalk and Ear Rot Diseases of Corn Caused by Diplodia
spp.. -----.............................-----....................----- ...................-- .......-............--- --......... 89
148 Investigation of Diseases of Ferns and Ornamental Plants.......................................... 89
150 Investigation of and Control of Fusarium Wilt, a Fungous Disease of Watermelons,
Caused by Fusarium niveum ......................................................................................... 89
151 Investigation of and Control of Fungous Diseases of Watermelons............................ 90
167 A Study of the So-Called "Rust" of Asparagus plumosus..................................... ....... 90
180 Control of Wilt of Tomatoes (Fusarium lycopersici Sacc.) in Florida...................... 90
181 Clitocybe Mushroom Root Rot of Citrus Trees and Other Woody Plants in Florida 91
182 Control of Blackspot (Phoma destructive Plowr.) of Tomatoes in Florida and in
T ransit ................................................................................................................................ 91
184 A Study of Strawberry Wilt or Crown Rot..................................................................... 92
193 Certain Studies of Decays of Citrus Fruits in Storage................................................ 92
196 A Study of the Spraying Requirements Necessary to Control Grape Diseases in
F lorida ................................................................................................................................ 93
242 Investigations of a Bark Disease of Tahiti Lime Trees................................................ 93
247 A Study of Sclerotium rolfsii in Florida, Its Host Relations, and Factors Influ-
encing Its Growth and Pathogenicity.......................................................................... 93
253 A Study of Rose Diseases in Florida and Their Control................................................ 94
254 Investigations of Fruit Rots of Grapes............................................................................ 94
259 The Collection and Preservation of Specimens of Florida Plants.............................. 94




Department
CITRUS
EXPERIMENT
STATION







EVERGLADES
EXPERIMENT
STATION


Number
3
21
24
26
34
35
83
102
185
233
85
86
87
88
89
90
168

169

170

171
172
195
202
203
204
205
206
207
208
209
210
211
212
219
249


Title Page
M elanose of Citrus and Its Control.. ..... --......-............................... ...-----...................... 96
Dieback of Citrus-..................- ........-.....-...................................---------........................ 97
Citrus Scab and Its Control -----------.................------............. ............................... .......... 97
Citrus Progeny and Bud Selection.................................---- -................................- ...........-... 98
Propagation Experiments with Citrus Plants of Various Kinds............................-----.... 98
Testing of Introduced and New Varieties and Hybrids of Citrus and Near-Citrus 99
Cover Crop and Green Manure Studies in Citrus Groves................................................ 99
Citrus Variety Tests, Including Rootstocks................................................................ .. 99
Investigation of Stem-end Rot of Citrus Caused by Phomopsis citri Faw................. 99
Control of Purple Scale and Whiteflies with Lime-Sulfur.........----.......................-- 99
Fruit and Forest Tree Trials and Other Introductory Plantings................................. 106
Soil Fertility Investigations Under Field and Greenhouse Conditions-....................... 108
Insect Pests and Their Control.............................................................................................. 109
Soils Investigations ............................................................................................... ... ..-- 112
W after Control Investigations .............................................................. ........................... 112
Studies in Crop Rotation ....................................................---- -----........ ..................---- -... 114
Studies Upon the Role of Special Elements in Plant Development Upon the Peat
and Muck Soils of the Everglades--.............. ........................... 114
Studies Upon the Prevalence and Control of the Sugarcane Moth Borer, Diatraea
saccharalis Fab., in South Florida.-...----------------------------........... .. .. 115
Studies Upon the Prevalence and Control of Rodents Under Field and Village
Conditions........................-..- ........ ...................................................... ............. .......-- 116
Cane Breeding Experiments ..---........-.--........------......--.....................----- .....--- .......... 116
General Physiological Phases of Sugarcane Investigations............................................ 117
Pasture Investigations on the Peat and Muck Soils of the Everglades........................ 118
Agronomic Studies with Sugarcane...... ............... ......... ............. ... .. 120
Forage Crops Investigations...........................-...........................................-...........---- .... 120
Grain Crop Investigations -..-..--.........-- ..-....-.......-----............. .---........ .......------. ... 121
Seed Storage Investigations.................. -- -.....................................----- ..- -....................... 122
Fiber Crops Investigations..........------ ----.- -...............................--- ..--.... ...... .. ------ 122
Cover Crop Investigations...............--- ........................................... ........................ ... 122
Agronomic Studies Upon the Growth of Syrup and Forage Canes in Florida....... 123
The Seed and Soil-Borne Diseases of Vegetable Crops..............-- -----..... --.................. 123
The Leaf Blights of Vegetable Crops.--- .... ------...........- .........................-... 125
Physiological Phases of Plant Nutrition .............- .......................................................... 126
Relation of Organic Composition of Agricultural Plants to Growth and Maturity.... 128
Beef and Dual-Purpose Cattle Investigations.. ............................................ ... 129
Nematode Investigations ..-...--........... -........ ................. ---------............................ 129














Department
NORTH FLORIDA
EXPERIMENT
STATION


SUB-TROPICAL
EXPERIMENT
STATION


WEST CENTRAL
FLORIDA
EXPERIMENT
STATION


Number
25
33
136
160
191


187
None
None
None
None
224
225
226
227

228

229


Title Page
Field and Laboratory Studies of Tobacco Diseases....................... ................--- -.. 132
Developing Strains of Cigar Wrapper Tobacco Resistant to Blackshank----.................... 134
Comparison of Various Grazing Crops with Dry-Lot Feeding for Pork Production.... 134
Fattening Fall Pigs for Spring M arket..................................................................... .... 136
Some Factors Affecting the Germination of Florida Shade Tobacco Seed and Early
Growth of the Seedlings.---.......-- .---..............--- ..... ..---....................--.....-- .. 136
Cotton Nutrition Studies ....................................................-.-----------............ 136
Beef and Dual-Purpose Cattle Investigations.........----.......... --------............ 137
Efficiency of Trench Silo for Preservation of Silage Crops......................................... 137
Columbia Sheep Performance Investigations................ ..... ............. ........... 138
Grain Crop Investigations................................................ ......................... .. ...--- ............ 138
Forage Crop Investigation........--.... .... ............... -- ...- ... .... ........................... 139
Variety Tests of Minor Fruits and Ornamentals......................---------............ 140
A avocado Culture Studies........................... ..... ......... ........................................... 142
C itrus Studies............................................................... .................................................... 143
Truck Crops Studies .......................................................................... ..------- -----.144
Tom ato V variety Tests..................................................................... ....... ................. 148
The Use of Peanuts and Peanut Products in Rearing Turkeys ----.. ---...................... .... 149
Confinement versus Range Rearing of Chicks...................................... .............. 150
Importance of Range Rotation in Poultry Production.................................................... 150
Study of Egg Production and Mortality from Pullets Reared Under Confinement
versus Range Conditions......................................................................... ................ 151
A Comparative Study of the Value of Milk Solids, Ground Peanut Kernels, Meat
Meal and Fish Meal in Fattening Broilers and Fryers............................................ 151
All-Night Lights versus No Lights on Single Comb White Leghorn Hens................ 152







Annual Report, 1935 15

REPORT OF BUSINESS MANAGER
Receipts and expenditures of State funds for the fiscal year ending
June 30, 1935, covering the Main Station and Branch Stations, were as
follows:.
STATION INCIDENTAL FUND
Receipts
Balance, 1933-34 ....................-....................... ....... $ 11,509.07
Receipts, 1934-35 .................................................... ... 25,995.14

Expenditures $ 37,504.21
Salaries .. ..................... $ 1,000.50
Labor ....................................... 4,123.78
Stationery and office supplies ................ 186.86
Scientific supplies .---------................................ 36.07
Feeding stuffs .............................................. 5,397.45
Fertilizers .............................................. 548.67
Sundry supplies ...............----- ............... 859.41
Communication service ............................ 254.52
Travel expense .-----------.............................. 493.94
Transportation of things .......................... 381.96
Publications ...................................... ... .. .......
Heat, light, power service ........................ 545.22
Contingent expense .................................... 204.71
Furniture, fixtures ...................................... 415.00
Library ......................................................... 7.50
Scientific equipment .............................. ..
Tools, machinery, appliances .................... 455.63
Livestock ..............--......................--.. 376.50
Buildings and lands, repairs ...............--... 1,292.43
Unexpended balance ...--------.............................. 20,924.06

37,504.21 $ 37,504.21

MAIN EXPERIMENT STATION
Receipts
Balance, 1933-34 .. ..................................... $ 12,087.87
Receipts, 1934-35 ...............-........................................ $170,243.00
Expenditures $182,330.87
Salaries ......................................................- $ 85,459.87
Labor ..... ------------------........................... 33,352.22
Stationery, office supplies ........................ 1,446.82
Scientific supplies ...................................... 1,626.46
Feeding stuffs .............................................. 6,112.57
Fertilizers. .......................................... .... 4,061.88
Sundry supplies ................... -----.............. 4,907.86
Communication service .............................. 2,030.87
Travel expense ....----------................................... 8,224.22
Transportation of things .......................... 1,532.65
Publications ........... .....--- .............-- .....-- 6,369.34
Heat, light, power, service ........................ 6,202.95
Contingent expense .................................---... 497.95
Furniture, fixtures ................-------................... 1,369.30
Library .....-..--......-- -------........... 1,670.06
Scientific equipment .................................. 1,461.90
Tools, machinery, appliances .................... 5,334.66
Livestock....................................................... 956.29
Buildings and lands, repairs ................... 9,711.23
Unexpended balance .................................. 1.77
182,330.87 $182,330.87







16 Florida Agricultural Experiment Station

CELERY DISEASE INVESTIGATIONS
Receipts
Balance, 1933-84 ........................................ ................ $ 1,430.52
Receipts, 1934-35 ................................... .......... 5,250.00

Expenditures $ 6,680.52
Salaries ................................................... $ 3,040.67
Labor ........................................................... 627.02
Scientific supplies ..................................... 692.55
Fertilizers .................. ...................... 156.35
Sundry supplies ..................................-- ... 46.70
Communication service -.......................... 51.53
Travel expense ............................................ 140.66
Transportation of things .......................... 6.34
Heat, light, power ...................................... 148.17
Furniture ..................................................... 160.64
Library .......................................................... 230.03
Scientific equipment .................................. 453.03
Tools, appliances --...................................... 894.25
Buildings, repairs ...................................... 25.34
Balance, unexpended ................................. 7.24
6,680.52 $ 6,680.52

CITRUS DISEASE INVESTIGATIONS
Receipts
Balance, 1933-34 --------.~............... ...................... $ .93
Receipts, 1934-35 ...........-.......... ----------- 3,500.00
Expenditures $ 3,500.93
Salaries .................................-- .......-...--- $ 2,876.00
Scientific supplies ...................................... 73.95
Travel expense ............-------............~......--- 351.82
Library ..............................................-- 17.62
Buildings, lands (Office rent) ................ 180.00
Unexpended balance .......--........... ------. 1.54
3,500.93 $ 3,500.93

FUMIGATION RESEARCH
Receipts
Balance, 1933-34 ......... .............................. $ 711.75
Receipts, 1934-35 ..............--------......... ..-----.........-- 3,062.50
Expenditures $ 3,774.25
Salaries .................... .... .... .....------ $ 2,131.00
Labor .........................................-.............. 1,067.98
Scientific supplies .....-----................................... 15.60
Sundry supplies .......-............---------.. 21.15
Communication service ......---... ---...... 10.50
Travel expense ............................................ 43.55
Transportation of things ..........................----- .50
Heat, light, power, service ......----........ 36.70
Furniture, fixtures ..-..------ ----- 25.05
Library ---.....---.......-....---- -- ....- 4.00
Scientific equipment ..--.. --........--.. ....... 42.48
Tools, machinery, appliances .................... 374.84
Unexpended balance ................-...-----......... .90
3,774.25 $ 3,774.25







Annual Report, 1935 17

GRAPE PEST INVESTIGATIONS
Receipts
Balance, 1933-34 -...----... --------------------. $ 71.90
Receipts, 1934-35 ........-- ---.. ----------- ------- 3,500.00
Expenditures $ 3,571.90
Salaries .................--------------. $ 2,367.00
L abor .............................................................. 396.50
Sundry supplies ..--...........---------------- 87.50
Communication service .........-------...... 13.00
Travel expense ...................------------ 352.75
Transportation of things .....--.....--------. .40
Heat, light, power, service----...... ----.... 40.23
Tools, machinery, appliances ...--.--..... 220.71
Buildings, repairs ..-.........---.--...-------- 92.67
Unexpended balance ........----.. ---------- 1.09
3,571.90 $ 3,571.90

PECAN INSECT INVESTIGATIONS
Receipts
Balance, 1933-34 ..........--...... ----- -. $ 1,165.16
Receipts, 1934-35 ---....-.....---..-----. ----------- 1,750.00
Expenditures $ 2,915.16
Salaries ......-..........----------- ------ $ 1,000.00
Labor ....................................-- --- -----.. 583.32
Stationery and office supplies ........... 15.99
Scientific supplies ............-.--.....-------. 307.85
Sundry supplies ........--......... ----------- 319.48
Travel expense ..............----------------- 20.80
Transportation of things ......------......... 3.00
Heat, light, power, service ........................ 52.92
Furniture, fixtures ...............------------ 189.10
Library ...................--- ------------- 3.75
Scientific equipment ............-------------- 250.59
Tools, machinery, appliances ..-----......... 95.67
Buildings, repairs ......----..... ----------- 71.59
Unexpended balance .........------ -------- 1.10
2,915.16 $ 2,915.16

POTATO DISEASE INVESTIGATIONS
Receipts
Balance, 1933-34 ---....-....-----.--------------- $ 109.89
Receipts, 1934-35 .-........--....---.---- --------- 5,250.00
Expenditures $ 5,359.89
Salaries .-.......---- -------.----- -..-- $ 3,045.00
Labor ..----....... .-------------- ------- 837.17
Scientific supplies ................--------- -- 41.05
Fertilizers -... ............--------------- 119.71
Sundry supplies ...........----..... ------ ---- 329.41
Communication service .--- -------- 62.69
Travel expense .............................. .......... 33.90
Transportation of things .......---.---.... 13.37
Heat, light, power, service ........................ 221.31
Contingent expense ......................----- ... 3.25
Library ------- -------------- 2.00
Tools, machinery, appliances .................. 528.97
Buildings, lands (Office rent) ...----..... 120.00
Unexpended balance .........---- ------------ 2.06
5,359.89 $ 5,359.89





18 Florida Agricultural Experiment Station





STRAWBERRY DISEASE INVESTIGATIONS
Receipts
Balance, 1933-34 ..................................--............ S 105.14
Receipts, 1934-35 .............. ........ ...... ......................... 6,300.00

S 6,405.14
Expenditures
Salaries .........................--- .. ............ $ 4,568.00
Labor ...........................................----.... 884.09
Scientific supplies ...................................... 43.92
Feeds ............----................................ -... ........ 28.30
Fertilizer .........................................-............ 87.45
Sundry supplies .---.....................................-- 228.05
Communication service ............................ 10.45
Travel expense .....................----................. 334.43
Transportation of things .......................... 1.43
Heat, light, power, service ...................... 90.70
Contingent expense .................................... 3.00
Tools, machinery, appliances .................... 23.40
Buildings, lands-repairs .......................... 101.85
Unexpended balance ....................... ........ .07

6,405.14 $ 6,405.14



TOMATO DISEASE INVESTIGATIONS
Receipts
Balance, 1933-34 ............................................................. $ 40.49
Receipts, 1934-35 -.....-....----............. ..-- ..........-----. 2,900.00

$ 2,940.49
Expenditures
Salaries ........................---.................-- ..- $ 2,030.00
Labor ............................................................ 358.98
Stationery and office supplies ............. 3.65
Scientific supplies ...................................... 5.97
Feeds .................................... ..-----.....-.. 32.29
Fertilizer ...............................................- ... 136.19
Sundry supplies ...............--......................... 38.68
Communication service .-..-....................... 51.70
Travel expense ........................................... 90.85
Transportation of things .......................... 9.27
Heat, light, power-service ...................... 86.42
Tools, machinery, appliances .................... 83.90
Buildings, lands-repairs ........................ 9.16
Unexpended balance .................................- 3.43

2,940.49 $ 2,940.49







Annual Report, 1935 19


CITRUS EXPERIMENT STATION
Receipts
Balance, 1933-34 .. ................. .................. $ 97.90
Receipts, 1934-35 .. ....... .............. ....... ........... .. 11,451.00
$ 11,548.90

Expenditures
Salaries ................. ............---------------- -.... $ 5,986.00
Labor ..................... ............. ...... ......... 2,859.38
Stationery and office supplies .................. 1.65
Scientific supplies ................................ 180.24
Feeds ........................ ........................... 234.81
Fertilizer................ ---........ --........ ---- 486.70
Sundry supplies ........................---------............ 197.33
Communication service .-------........................ 130.08
Travel expense ............................................ 236.70
Transportation of things............................ 31.67
Heat, light, power-service ......... ..- 506.13
Contingent expense ...--------------.... ------. 13.25
Furniture, fixtures ..--...................-------...... 89.10
Library ...................................... ----- 10.00
Scientific equipment ......................----- 155.10
Tools, machinery, appliances .................... 165.69
Buildings and lands-repairs .....--.--... 264.54
Unexpended balance -------------- .53
11,548.90 $ 11,548.90


EVERGLADES EXPERIMENT STATION
Receipts
Balance, 1933-34 .-----...........---.-----.----.. $ 37.36
Receipts, 1934-35 .................................... $ 45,339.00
Continuing appropriation, yearly ........... 5,000.00 50,339.00
$ 50,376.36
Expenditures
Salaries ---------........................................----- $ 21,751.63
Labor ............. ------ ----................................. 17,157.29
Stationery, office supplies .-........---.... .. 167.64
Scientific supplies ......----.............-.. -.- 557.62
Feeds .....---........... .......------.- 2,289.22
Fertilizer........................................................ 394.23
Sundry supplies ................ .------...---- 1,605.10
Communication service .............------ .224.25
Travel expense ................................... .... 732.72
Transportation of things .......................... 95.70
Heat, light, power, service ....................... 2,423.57
Contingent expense ...--..... ..........----..-- 36.27
Furniture, fixtures ....---..............-----..- 192.94
Library ....................................... 220.34
Scientific equipment .. ----......--..... ----- 42.29
Tools, machinery, appliances ............ 1,535.59
Livestock......... ...... ..................... 18.00
Buildings, lands -------.....-...........------. 930.25
Unexpended balance .................................. 1.71
50,376.36 $ 50,376.36







20 Florida Agricultural Experiment Station



NORTH FLORIDA EXPERIMENT STATION
Receipts
Balance, 1933-34 ................. ........................................ $ 18.32
Receipts, 1934-35 ............................................................ 20,968.00

$ 20,986.32
Expenditures
Salaries .......................................---- $ 12,180.00
Labor .............................................................. 2,664.00
Stationery, office supplies ........................ 6.82
Scientific supplies ..................................... 77.16
Feeds .............................................................. 781.18
Fertilizer........................................................ 399.58
Sundry supplies .......................................... 596.50
Communication service .............................. 115.25
Travel expense ............................................ 47.25
Transportation of things .......................... 163.03
Heat, light, power-service ...................... 644.93
Contingent expense .................................... 22.00
Furniture, fixtures ...................................... 38.08
Library .......................................................... 30.32
Scientific equipment .................................. 1.60
Tools, machinery, appliances .........-- ...... 1,405.85
Buildings, lands .......................................... 1,811.87
Unexpended balance .................................. .90

20,986.32 $ 20,986.32


SUB-TROPICAL STATION
Receipts
Balance, 1933-34 ................. ........................................ $ 17.71
Receipts, 1934-35 ....................................-....................... 10,579.00

$ 10,596.71
Expenditures
Salaries ...-----......---.....--..-...--......--.. $ 4,665.00
Labor .............................................................. 3,344.72
Stationery, office supplies ........................ 7.10
Scientific supplies ...................................... 79.41
Feeds .............................................................. 3.90
Fertilizer........................................................ 540.68
Sundry supplies ........................................ 524.39
Communication service .............................. 105.42
Travel expense ............................................ 500.00
Transportation of things .......................... 85.72
Heat, light, power-service ...................... 380.06
Contingent expense ..... .................................. 4.50
Library .......................................................... 15.47
Scientific equipment .................................. 20.05
Tools, machinery, appliances ............ --262.38
Buildings, repairs --.........- ---................... 55.81
Unexpended balance .................................. 1.50

10,596.71 $ 10,596.71







Annual Report, 1935 21









WATERMELON DISEASE INVESTIGATIONS
Receipts
Balance, 1933-34 ............................... ----.... $ 17.63
Receipts, 1934-35 .--............. ......------ --. ------ 6,229.00
$ 6,246.63
Expenditures
Salaries .........................----------- ---...... $ 3,637.00
Labor .................................................---. 1,085.42
Stationery and office supplies .............. 8.77
Scientific supplies ...........-------------- --. 55.90
Fertilizer............................. ......................-- 161.96
Sundry supplies ......................---.---. ..- 179.76
Communication service .......----..---------- 65.34
Travel expense ....................--.-------. 263.78
Transportation of things .......................... 12.47
Heat, light, power-service ............-- 121.39
Contingent expense .................... --------- 3.80
Furniture, fixtures ................---------- 97.20
Library ..................-................ 11.38
Tools, machinery, appliances .................... 24.43
Buildings, lands, repairs .-.....- ---.-----. 517.32
Unexpended balance .................-- ---- .71
6,246.63 $ 6,246.63






EVERGLADES STATION, INCIDENTAL
Receipts
Balance, 1933-34 -..................------- -------..- $ 2,906.71
Expenditures
Sundry supplies .......--........ --------- $ 1.15
Buildings, lands ................----------- 2,905.56
2,906.71 $ 2,906.71


I








Florida Agricultural Experiment Station


PUBLICATIONS, NEWS, RADIO
Perhaps at no time since it was founded 48 years ago has the Experi-
ment Station disseminated more information than it did during the fiscal
year 1934-35, and this information was of interest and value not only
to Florida farmers but also to a large number of scientific workers through-
out the United States and even in other parts of the world. During the
year one of its bulletins was reviewed in a scientific publication m the
Union of Soviet Socialist Republics (Russia).
While a high percentage of the research work conducted by this station
is peculiar to Florida and conditions obtaining here, yet some of it does
appeal to other sections of the country. It is felt that the public, both
in Florida and elsewhere, is growing into a great appreciation of the worth
of the research work conducted by the station as a result of the vast
amount of work which has been done and the excellent distribution of the
information obtained.
There have been little changes in the editorial and mailing work during
the year-only an enlargement of the lines already being followed and
greater use particularly made of newspapers and farm papers. Staff mem-
bers of the Editorial and Mailing Department, as usual, have devoted ap-
proximately half of their time to work for the Agricultural Extension
Service.
PRINTING AND DISTRIBUTING BULLETINS
Thirteen new bulletins, slightly more than one a month, were printed
during the year, bringing the grand total for bulletins printed since the
establishment of the institution to 281. Five of the new bulletins were
technical in nature and eight popular. They ranged in size from 12 to 100
pages, and in edition from- 4,000 to 15,000, giving a total of 584 pages and
104,500 copies.
Except for the list of libraries and scientific workers throughout the
country, bulletins are distributed only on request. Yet the demand for
Experiment Station bulletins continues to grow with the more widespread
knowledge obtained, and often the limited editions of bulletins printed are
exhausted long before they should be.
Bulletins issued during the fiscal year, with titles, pages and number
of copies of each, are listed below.
Bul. Title Pages Edition
269 Effect of Frequent Cutting and Nitrate Fertilization on
the Growth Behavior and Relative Composition of
Pasture Grasses ---------------............. ..-..............-- ....... 48 6,000
270 Fertilizer Experiments with Pecans-----............................... 48 7,500
271 The Asparagus Caterpillar; Its Life History and Control 28 5,000
272 Avocado Production in Florida.............................................. 100 6,000
273 A Preliminary Report on Zinc Sulphate as a Corrective
for Bronzing of Tung Trees.......................... ................... 36 10,000
274 Management of Dairy Cattle in Florida...........---...-............. 52 15,000
275 The Feeding Value and Nutritive Properties of Citrus
By-Products ................................................................ ............ 228 12,000
276 Farmers' Cooperative Associations in Florida-III. Busi-
ness Analysis of Hastings Potato Growers' Association 64 7,500
277 The Effect of Certain Environmental Factors on the
Germination of Florida Cigar-Wrapper Tobacco Seeds 48 4,000
278 Effect of Freezing Temperatures on Sugarcane in the
Florida Everglades .............................. ..................... 12 4,000







Annual Report, 1935 23


279 The Digestible Nutrient Content of Napier Grass Silage,
Crotalaria Intermedia Silage and Natal Grass Hay...... 28 5,000
280 The Tung Oil Tree...................................68 15,000
281 Beef Cattle Improvement in Florida, I and II............. 24 7,500
SUMMARY OF BULLETINS
269. Efects of Frequent Cutting and Nitrate Fertilization on the
Growth Behavior and Relative Composition of Pasture Grasses. (W. A.
Leukel, J. P. Camp and J. M. Coleman, pp. 48, figs. 14.) Plants cut fre-
quently maintained a more vegetative growth condition and produced
greater horizontal growth of stolons, thus resulting in better sod formation.
Composition at different stages of growth, with and without nitrate fer-
tilizers, discussed. Technical bulletin.
270. Fertilizer Experiments with Pecans. (G. H. Blackmon and R. W.
Ruprecht, pp. 48, figs. 5.) Fertilizers gave increasingly profitable returns
in nut yields in the experiments conducted in western Florida counties.
The increase in cross-section of trunks of fertilized trees showed the benefits
of fertilizers. Fertilizers did not materially affect the composition of nuts.
271. The Asparagus Caterpillar: Its Life History and Control. (J. W.
Wilson, pp. 28, figs. 5.) Reports life history studies of this, the most
abundant of the night flying moths in Florida ferneries. Lists parasites.
Best artificial control obtained by timely dusting with undiluted lead arsen-
ate. Technical bulletin.
272. Avocado Production in Florida. (H. S. Wolfe, L. R. Toy and
Arthur L. Stahl, pp. 100, figs. 31.) Contains sections on history, distribu-
tion, uses, botany, varieties, pollination, analyses, culture, diseases, insects
and other pests of the avocado in Florida.
273. A Preliminary Report on Zinc Sulphate as a Corrective for Bronz-
ing of Tung Trees. (Harold Mowry and A. F. 'Camp, pp. 36, figs. 7.)
Treatments of bronzed tung trees with 89 percent zinc sulphate gave
remarkable response, bringing the trees out of the unhealthy condition
and enabling them to withstand cold weather better. Soil treatments pro-
duced results in most cases.
274. Management of Dairy Cattle in Florida. (P. T. Dix Arnold, R. B.
Becker and Bruce McKinley, pp. 52, figs. 11.) Discusses breeds of dairy
cows, selection of cows and bulls, keeping records, raising replacements,
mineral supplements, factors affecting milk yields and butterfat content,
and economic phases of dairying.
275. The Feeding Value and Nutritive Properties of Citrus By-Products.
(W. M. Neal, R. B. Becker and P. T. Dix Arnold, pp. 28, fig. 1.) Experi-
ments showed that dried grapefruit refuse from canning plants was a good
feed for cattle, the animals relishing the feed and maintaining good con-
dition.
276. Farmers' Cooperative Associations in Florida-III. Business Anal-
ysis of the Hastings Potato Growers' Association. (H. G. Hamilton and
Marvin A. Brooker, pp. 64, figs. 5.) Reports on the organization and
working of the association, marketing operations, purchase of supplies,
balance sheet, and the credit corporation.
277. The Efect of Certain Environmental Factors on the Germination
of Florida Cigar-Wrapper Tobacco Seeds. (R. R. Kincaid, pp. 48, figs. 2.)
Sets forth results of experiments which showed that the cardinal tempera-
tures for germination of Florida cigar-wrapper tobacco seeds are approxi-
mately 10, 24 and 34 degrees Centigrade. Light was required for the
germination of all samples. Some seeds germinated in darkness when
temperatures were alternated daily. Technical bulletin.







Florida Agricultural Experiment Station


278. Efects of Freezing Temperatures on Sugarcane in the Florida
Everglades. (B. A. Bourne, pp. 12, figs. 3.) The sugarcane P.O.J. 2725
deteriorated very slowly after being frozen during the season 1934-35,
making possible the continuance of sugar house operations for 75 days
after the cane was frozen, and indicating the favorable climate for sugar-
cane in the Florida Everglades. Technical bulletin.
279. The Digestible Nutrient Content of Napier Grass Silage, Crotalaria
Intermedia Silage, and Natal Grass Hay. (W. M. Neal, R. B. Becker and
P. T. Dix Arnold, pp. 28, figs. 0.) Reports digestion trials with these hitherto
unreported crops. Napier grass was low in crude protein and high in
fiber. C. intermedia made palatable silage of good protein content but
high in fiber. Natal grass hay was practically equal to timothy in total
digestible nutrients. Technical bulletin.
280. The Tung-Oil Tree. (Wilmon Newell, Harold Mowry, R. M. Bar-
nette, A. F. Camp and R. D. Dickey, pp. 68, figs. 30.) Describes the tree,
its botanical relationships and its adaptability, lists the uses of tung oil
and importations into the United States, gives something of the industry
in China and the beginnings and development in this country, with sug-
gestions on varieties, soils, propagation, culture, bronzing, harvesting and
expressing the oil.
281. Beef Cattle Improvement in Florida. (Bradford Knapp, Jr., and
A. L. Shealy, pp. 24, figs. 16.) First section devoted to improvement of
beef herds through breeding, second section to a method of grading range
breeding cows. Contains pointers on selection of foundation cows and
purebred bulls for beef herds.

PRESS BULLETINS
Fifteen new press bulletins, each containing two pages of succinct
information for Florida farmers, were printed and four others were re-
printed during the year. In most cases 3,000 copies constituted the edition,
but 5,000 each were printed of 465 and 466 while the issue of 472 and 451
consisted of 6,000 each. Only 2,500 copies of the bulletin lists were printed.
Following is a list of press bulletins issued and reprinted during the year.
No. Title Author
465 The Screw Worm Fly...............................D. A. Sanders and A. N. Tissot
466 Dried Grapefruit Refuse-A Valuable Feed
-W. M. Neal, R. B. Becker and P. T. Dix Arnold
467 Control of Phoma Rot of Tomatoes....W. B. Tisdale and Stacy Hawkins
468 Durable W hitewashes.......................................................... R. W Ruprecht
469 Spraying to Control Grape Rots in Florida Vineyards........K. W. Loucks
470 Mice and "Gophers" in Watermelon Fields............................C. C. Goff
471 Commercial Control of Watermelon Anthracnose..............M. N. Walker
472 The Suwannee Cowpea.................................................... Geo. E. Ritchey
473 The Destructor Scale................................ .............E. W. Berger
474 Blackberries and Dewberries. ...........................................Harold Mowry
475 Colds and Roup in Poultry........................................................M. W. Emmel
476 Infectious Laryngotracheitis (Infectious Bronchitis) in Poultry
-M. W. Emmel
477 Coccidiosis in Chickens...................................................M. W. Emmel
Bulletin List (printed twice)
402 Gas the Ants (reprint)...........................................................J. R. W atson
431 Gummosis and Psorosis of Citrus Trees (reprint)............A. S. Rhoads
432 Treatment of Gummosis and Psorosis of Citrus Trees (reprint)
-A. S. Rhoads
451 Crotalaria (reprint).............................W. E. Stokes and W. A. Leukel








Annual Report, 1935


"LITTLE STORIES OF FLORIDA AGRICULTURE"
As a means of bringing about greater popular appreciation of the
Experiment Station and its work, a series of 12 envelope stuffers relating
"Little Stories of Florida Agriculture" were issued during the year. Five
thousand copies of each were printed. Ten of these were distributed, one
each month from September to June, inclusive. Copies were placed in all
outgoing correspondence from the Main Station and branch stations.
These were interesting little tracts, each four pages long and each
telling of some important accomplishment of the Experiment Station which
has contributed in outstanding and important ways to the state's farming
success. Titles included Passing of the Pigtail Parade (the story of tung
oil); Building Beef Instead of Bones (overcoming "salt sick" in cattle);
Extending Hands Across the Seas (trades of beneficial insects with foreign
countries); Locating Leaks in Citrus Costs, with particular reference to
packinghouse operations; Science Unlocked Vast Farm Empire through
soils studies in the Florida Everglades; More Than Streak of Lean With
Fat (or findings which show food value of Florida crops); Going in the
Air After Plant Food, the introduction of outstanding leguminous crops;
Guarding Smokers from Nude Cigars by developing strains of cigar-
wrapper tobacco resistant to blackshank; Starving Pests in Truck Fields,
the summer fallow method of controlling nematodes; Enlisting Nature
in War on Pests, telling of the research which led to the use of friendly
fungi in Florida citrus groves.
That the public found these of interest is evidenced by the fact that
numerous requests were received for copies.

SPECIAL CAMPAIGNS
The Editorial Department assisted the Agronomy Department in the
distribution of samples of seed corn and cowpeas which the latter division
was anxious to have tested in all parts of Florida during 1935. Stories
in both newspapers and farm papers and announcements over the radio
were utilized in bringing these seeds to the attention of Florida farmers,
who then requested samples.
Through the efforts of this office and the Animal Husbandry Depart-
ment, announcement of the discovery by a Florida Station veterinarian
of the cause of leukemia in chickens-a disease which has baffled scientists
for years-was spread throughout the limits of the United States and
even into foreign countries. It resulted in much interest and discussion.
News agencies, radio, poultry magazines and the farm press carried the
announcements.
PRESS STORIES AND ARTICLES
Members of the daily, weekly and farm press circulating in Florida
continued to give wholehearted cooperation in printing news and articles
from the Florida Experiment Station. In turn, only worth while stories
and articles with genuine value to readers were supplied to the papers.
The Agricultural News Service clipsheet distributed weekly by the
Agricultural Extension Service carried from one to six or eight Experiment
Station stories in each issue, and these were largely reprinted by weekly
papers. Special stories were supplied to dailies direct and through the
Associated Press wire and mail service. One daily carried a department
of questions and answers from the Experiment Station each Sunday during
the year.
Three Florida farm papers used 15 articles supplied by the Editors
during the year concerning the Experiment Station and its work. These


9








26 Florida Agricultural Experiment Station

articles amounted to 601 column inches. The papers also printed numerous
articles by other members of the staff, some supplied direct but mostly
furnished through the Editorial Department. Copies of radio talks made
by staff members often were printed in these state farm magazines. Ques-
tions and answers copy was supplied regularly to one Florida paper, the
11 issues printed during the fiscal year containing 230 inches of this copy.
One Southern farm paper carried four articles, 27 column inches, relating
to work of the Florida Station, while four national journals carried one
story each for a total of 33 column inches of space.

FARM RADIO PROGRAMS
Experiment Station staff members participated frequently in farm radio
broadcasts over WRUF, state station at Gainesville. Their talks came
during the Florida Farm Hour at noon each day, supervised by the Agri-
cultural Extension Service. The Editors scheduled these programs and
assisted in staging them.
A recapitulation shows that 154 talks were made by 28 different Station
staff members during the year. In many cases, the talks made were
reworked into farm flashes which were supplied to five other Florida
stations for their daily broadcasts.

SCIENTIFIC AND POPULAR ARTICLES IN JOURNALS
Popular and scientific journals throughout the country print many
articles by members of the Station staff, sent either direct or through
the Editorial Office, thus making available accurate, scientific information
of great value to investigators and farmers. Only a few of these articles
are edited in this office. Following is a list of such articles printed during
the year, as supplied by staff members.
A bibliography on the use of hydrocyanic acid gas as a fumigant. R. J.
Wilmot. Mimeo. Circ. Apr. 18, 1935.
A comparative study of certain morphological characters of sugarcane X
sorgo hybrids. B. A. Bourne. Jour. Agr. Research 50:539-552. Mar.
15, 1935.
A comparison of native and partially improved pastures. W. E. Stokes and
A. L. Shealy. Proc. Asso. Sou. Agr. Workers. 1935.
Additional notes on the oleander caterpillar. H. E. Bratley. Fla. Ento-
mologist, 18:3. 1934.
A Discussion of the Citrus Marketing Agreements. C. V. Noble. Jour.
Farm Economics, May 1935.
A new Myzus from Florida. A. N. Tissot. Fla. Entomologist, 18:4. 1935.
A new station for Trillium ludovicianum. Erdman West. Torreya 35:63-
64. 1935.
A new Tabanus (Diptera) from Florida. G. B. Fairchild. Fla. Entomolo-
gist, 18:4. 1935.
A preliminary report on the etiology of fowl paralysis, leucosis and allied
conditions in the domestic fowl. M. W. Emmel. Jour. Amer. Vet. Med.
Asso. 75, n.s.38. 1934.
A program for citrus aphid control. J. R. Watson. Citrus Industry, Feb.
1935.
A response of chlorotic corn plants to the application of zinc sulfate to
the soil. R. M. Barnette and J. D. Warner. Soil Science, 39:2, 145-
159. 1935.
A study of the palatability and possible toxicity of eleven species of
crotalaria, especially C. spectabilis Roth. R. B. Becker, W. M. Neal,
P. T. Dix Arnold, and A. L. Shealy. Jour. Agr. Research, 50:911-922.
1935.








Annual Report, 1935


Avocado varieties in the light of recent experience. H. S. Wolfe. Proc.
Fla. State Hort. Soc. 1935.
Crotalaria spectabilis Roth. seed poisoning in swine. M. W. Emmel, D. A.
Sanders, and W. W. Henley. Jour. Amer. Vet. Med. Asso., 86, n.s. 39.
1935.
Cover crops and the turnover of plant nutrients. R. M. Barnette and
H. W. Jones. Citrus Industry, 15:12. Dec. 1934.
Comparison of various Southern pasture grasses for grazing purposes.
Geo. E. Ritchey. Proc. Asso. Sou. Agr. Workers. 1935.
Certain soil deficiencies and their correction. R. M. Barnette. Citrus
Industry, 15:12. Dec. 1934.
Cattle raising in the Everglades. R. W. Kidder. Florida Grower, 42:8.
Oct. 1934.
Diseases of lime trees. W. B. Tisdale. Proc. Fla. State Hort. Soc. 1934.
Diseases of roses and their control. W. B. Shippy. Bul. Fla. Rose Society.
1934.
Earth pearls of citrus roots. J. R. Watson. Florida Grower, July, 1934.
Effect of inoculated sulphur, lime and mercury compounds on the yield
of potatoes. A. H. Eddins. Amer. Potato Jour. Nov. 1934.
Effects of the freeze on some citrus insects. J. R. Watson. Fla. Entomolo-
gist, 18:4. 1935.
Electrometric determination of chlorides in the ash and sap of plants and
in ground waters. J. R. Neller. Indust. and Eng. Chemistry, Analytical
Edition, 6:6, 426. 1934.
Fall fertilizers for citrus groves. R. W. Ruprecht. Florida Grower, 42:8.
Oct. 1934.
Food habits of Leptoglossus Gonagra. W. L. Thompson. Fla. Entomologist,
18:3. 1934.
Fundamentals in pasture research. W. A. Leukel. Proc. Asso. Sou. Agr.
Workers. 1935.
Histological studies of a seedling disease of corn caused by Gibberella
moniliformis. R. K. Voorhees. Jour. Agr. Research, 49:11, 1009-1015.
1934.
Influence of season and advancing lactation on butterfat content of Jersey
milk. R. B. Becker and P. T. Dix Arnold. Journ. Dairy Science, 18:
389-399. 1935.
Manganese sulphate for vegetable crops. G. R. Townsend. Florida Grower,
43:1. Jan. 1935.
Neutral fertilizers, what they are, and how they act. R. W. Ruprecht.
Citrus Industry, 16:2. Feb. 1935.
Notes on Neotermes castaneus Burm. W. L. Thompson. Fla. Entomologist,
18:3. 1934.
Notes on Nezara viridula L. J. R. Watson. Fla. Entomologist, 18:3. 1934.
Peanut breeding at the Florida Experiment Station. F. H. Hull. Proc.
Asso. Sou. Agr. Workers. 1935.
Potato diseases on the Lower East Coast. S. 0. Hawkins. Florida Grower,
44:2. Feb. 1935.
Progress in zinc sulphate studies. A. F. Camp. Proc. Fla. State Hort. Soc.
1935.
Pullorum disease and its treatment. M. W. Emmel. Florida Poultryman,
1:4-5. 1935.
Rare elements and plant growth. R. W. Ruprecht. Comm. Fertilizer,
50:4. Apr. 1935.
Rate of decomposition of organic matter in Norfolk sand as measured by
the formation of carbon dioxide and nitrates. C. E. Bell. Jour. Agr.
Research, 50:9, 717-730. 1935.


=Ed








Florida Agricultural Experiment Station


Response of certain field crops to zinc. J. P. Camp. Proc. Asso. Sou. Agr.
Workers. 1935.
Results with cover crops for pecans in 1933. G. H. Blackmon. Proc. Natl.
Pecan Assn. 1934.
Results with pecan fertilizer experiments in 1933. G. H. Blackmon. Proc.
Natl. Pecan Assn. 1934.
Sclerotial rot of corn caused by Rhizoctonia zeae, n. sp. R. K. Voorhees.
Phytopath. 24:11, 1290-1303. 1934.
Some field experiments for the control of melanose and stem-end rot of
citrus. W. A. Kuntz and G. D. Ruehle. Proc. Fla. State Hort. Soc. 1935.
Some further observations on Margarodes in citrus groves. J. R. Watson.
Proc. Fla. State Hort. Soc. 1935.
Some lessons learned in two freezes. A. F. Camp. Proc. Fla. State Hort.
Soc. 1935.
Some pathological observations on sugar cane x sorghum hybrids in Florida.
B. A. Bourne. Phytopath. 24:11, 1314-1315. 1934.
Spraying for the control of citrus scab. G. D. Ruehle. Citrus Industry,
16:5. May, 1935.
Sprays to control tomato disease. S. O. Hawkins. Florida Grower, 42:7.
Sept. 1934.
Spring citrus fertilization. R. W. Ruprecht. Citrus Industry, 16:2. Feb.
1935.
Sub-tropical experiment station. H. S. Wolfe. Florida Motorist, 1935.
Suitable soils for tung trees. R. M. Barnette. Florida Grower, 44:2. Feb.
1935.
Termites and ants in banked trees. J. R. Watson. Citrus Industry, Nov.
1934.
--The bulbs called Zephyranthes. H. H. Hume. Garden, 1:1, 16-20. March,
1935.
The control of purple scale and rust mites with lime-sulphur solution.
W. L. Thompson. Citrus Industry, July, 1935.
The distribution of iris in Florida. H. H. Hume. Bul. Amer. Iris Soc.
Apr. 1933.
The effect of acid and non-acid fertilizers on the soil. R. W. Ruprecht
and C. E. Bell. Proc. Fla. State Hort. Soc. 1935.
The effect of copper sulfate on the yield and quality of oranges. W. E.
Stokes. Proc. Asso. Sou. Agr. Workers. 1935.
The effect of fertilizers and soil types on the mineral composition of vege-
tables. J. M. Coleman and R. W. Ruprecht. Jour. Nutrition, 9:1, 51-
62. 1935.
The effect of improved diet on children with a moderate degree of hook-
worm infection. O. D. Abbott. Jour. Home Economics, Nov. 1934.
The effect of nitrogen fertilization and frequency of clipping on pasture
grass yield and composition. G. E. Ritchey. Proc. Asso. Sou. Agr.
Workers. 1935.
The etiology of fowl paraylsis (Neurolymphomatosis gallinarum Pappen-
heimer), leucosis and allied conditions in the fowl. M. W. Emmel.
Proc. U. S. Livestock San. Asso. 1934.
The etiology of fowl paralysis (Neurolymphomatosis gallinarum Pappen-
heimer), leucosis and allied conditions in the fowl. M. W. Emmel.
Jour. Amer. Vet. Med. Asso. 86: n.s. 39. 1935.
The etiology of fowl paralysis, leucosis and allied conditions in the fowl.
M. W. Emmel. Vet. Med. 30:2. 1935.
The importance of soil organic matter. R. M. Barnette. Citrus Industry,
16:6. June, 1935.








Annual Report, 1935


The mineral content of soils as related to "salt sick" of cattle. O. C. Bryan
and R. B. Becker. Jour. Amer. Soc. Agronomy, 27:120-127. 1935.
The reaction of native iris soils in Florida. H. H. Hume. Bul. Amer. Iris
Society. Jan. 1934.
The results of five years fertilizer tests on pasture grass plots at Gaines-
ville, Florida. G. E. Ritchey. Proc. Asso. Sou. Agr. Workers. 1935.
The toxicity of Crotalaria spectabilis Roth. to livestock and poultry. E. F.
Thomas, W. M. Neal, and C. F. Ahmann. Jour. Amer. Soc. Agronomy,
27:499-500. 1935.
The trend of citrus insect control in Florida. J. R. Watson. Proc. Fla.
State Hort. Society. 1935.
The use of zinc sulphate on citrus. A. F. Camp. Citrus Industry. Oct.
1934.
The viability of cotton seed and the resultant yield of cotton as influenced
by place of origin, plant nutrients, and soil moisture. W. A. Carver.
Proc. Asso. Sou. Agr. Workers. 1935.
Thysanoptera of the Geenton. J. R. Watson. Fla. Entomologist, 18:3.
1934.
Undesirable characteristics of some pecan varieties. G. H. Blackmon. Proc.
Natl. Pecan Asso. 1934.
Why potato production varies in Florida. W. M. Fifield. Fla. Grower,
42:9. Nov. 1934.
Yield records for several of the older pecan varieties grown in Florida.
G. H. Blackmon. Proc. Southeastern Pecan Grs. Asso. 1935.
Yield, sizes and kernel percentages of nuts produced in a cover crop ex-
periment at Monticello, Florida. G. H. Blackmon. Proc. Southeastern
Pecan Grs. Asso. 1935.


9








30 Florida Agricultural Experiment Station

THE LIBRARY
A summary of some of the activities of the library for the fiscal year
ending June 30, 1935 is given below:
Number volum es bound.......---........................-........-....... ..................... 192
'Number volumes received through purchase, gift or exchange.... 190
Total number volumes in library................... .....---.......... 12,545
Bulletins, serials, etc., received............................. ...-- ......................- 8,795
Catalog cards prepared, typed and added to card catalog............ 19,169
Books and journals lent to local staff....................... ................ 4,012
Books and journals lent to branch stations............--................. 354
Books borrowed from other libraries.......................... ........... 102
The data in the above table give but little idea as to the actual work
in the library the past year. Over 300 persons, including the staffs of the
Experiment Station, Agricultural Extension Service, faculty of the College
of Agriculture and agricultural students, make use of the library facilities
almost constantly. In addition, the library is used extensively by members
of the general faculty and student body, by farmers and growers, and by
county and home demonstration agents.
Accurate record is kept of material loaned, but for that used within
the library such a record is not feasible. A check was made for one week
in March and it was found that for the period 479 requests were made at
the desk. The requests included definite references, known subjects only,
works by specific authors, obscure references requiring intensive search
of the literature, and literature searches relative to various research prob-
lems. The attempt is made at all times to provide the necessary literature
for investigations under way and those newly instituted.
The library subscribes to the UNION LIST OF SERIALS, which makes
possible the quick location of periodicals in other libraries available for
inter-library loan. A nearly complete index to all agricultural literature
is available in the AGRICULTURAL INDEX, READER'S GUIDE, EX-
PERIMENT STATION RECORD and the library's catalog.
With the changes in the agricultural set-up of the Nation, an immense
number of publications, many mimeographed or multigraphed, have been
released from Washington, D. C., and elsewhere. This material requires
a great amount of attention if it is to be made available for present or
future reference. Exclusive of this type of material, 8,785 bulletins, pam-
phlets, serials, etc., on agricultural subjects, have been received.
The arrangement whereby books, bulletins and journals are supplied
to the workers of the branch stations by circulation has been continued,
and has effected a considerable saving in subscription costs.








Annual Report, 1935


AGRICULTURAL ECONOMICS
Most of the regular projects in the Department became inactive or were
slowed down to make way for the emergency type of farming project
started on May 1, 1935. Much work had been accomplished under this
emergency project by the end of the fiscal year, June 30, 1935. Statistical
data had been summarized in readiness to bring out the trends in farming
types in different areas of Florida as well as to show the present status
in the different areas. A tentative type-of-farming map was prepared for
the state, based upon the statistical data, climate and soils information,
as well as upon the general knowledge of Station workers and other re-
liable sources. Work is now in progress in obtaining definite farm man-
agement data in specific type areas in order to ascertain the accuracy of
the type map.
Cost of production and grove organization studies of Florida citrus were
also continued during the year, and much progress was made with the
study of pre-cooling and of refrigeration in transit as affecting the cost
of marketing, quality and price of citrus fruits.

AGRICULTURAL SURVEY OF SOME 500 FARMS IN THE GENERAL
FARMING REGION OF NORTHWEST FLORIDA
Purnell Project No. 73 C. V. Noble and Bruce McKinley
Inactive during 1934-35, due to necessity of carrying Federal Project
1100 (State Purnell Project 262) to early completion.

FARMERS' COOPERATIVE ASSOCIATIONS IN FLORIDA
Purnell Project 154 H. G. Hamilton and C. V. Noble
The third phase of this study was completed during the fiscal year and
is incorporated in bulletin 276, recently received from the press. This is
a monographic study of the Hastings Potato Growers' Association and
covers the 12 seasons since the organization of the Association on July 1,
1922, through June, 1934. This Association was chosen for the study
because of the completeness and the availability of its records since its
organization. The full cooperation and assistance of the officers of the
Association in making available their financial records, which form the
basis for this study, made the work possible. Some of the most important
points brought out by this study are given below.
1. The Hastings Potato Growers' Association is a non-capital stock
corporation controlled on the one-member one-vote principle. The equity
of the members is in proportion to the use made of the Association.
2. Official U. S. D. A. grades for potatoes have been used as a basis
for grading.
3. Daily pools are operated. Off-grade potatoes are not included in
the pool.
4. Sales are made on an f.o.b. basis when possible. When the sales
are not made on f.o.b. bases they are either consigned or sold on a price
arrival basis.
5. Brokerage expense amounted to approximately 56 percent of the
total selling expense.
6. A field department is maintained to assist the growers in their pro-
duction problems and to keep the sales department informed as to daily
and weekly' supplies.
7. To improve the pack and better meet the demands of customers,
a packing plant was installed at the beginning of the 1931-32 season.


.0ME






Florida Agricultural Experiment Station


8. To keep the credit structure of the Association in a strong position,
a revolving growers' reserve fund is maintained by making a reserve
charge for each unit of supplies furnished. This charge ranged from 6.5
percent of the value of the supplies for the 1933-34 season to 10.6 percent
for the 1931-32 season and averaged 8.1 percent for the 12 seasons. The
growers' reserve fund retain for cash advanced ranged from 4.5 percent
of the cash advanced for the 1922-23 season to 11.2 percent for the 1932-33
season and averaged 5.9 percent for the 12 seasons. A total of $225,824.60
has been returned to the members from the growers' reserve fund.
9. Cash advanced and value of supplies furnished ranged from $73.16
per acre for the 1932-33 season to $160.39 for the 1926-27 season and aver-
aged $126.33 for the 12 seasons.
10. Losses occurring in growers' accounts have been written off through
a sinking fund. The sinking fund is maintained largely by the net interest
income and the net income from operations.
11. The best credit risks were those members who planted 100 percent
of their available potato land to potatoes. Members having 100 percent
of their potato land planted to potatoes on the average owed the Association
$129.10, while members having less than 50 percent of their available po-
tato land planted to potatoes on the average owed the Association $2,232.10.
Members out of debt to the Association had on the average more acres
of potatoes than members in debt to the Association.
12. Charges for selling potatoes averaged 5.2 percent of the sales.
Charges for handling supplies averaged 2.2 percent of the value of the
supplies. On the whole the expenses for the services rendered by the
Association were kept within the charges made for these services.

COST OF PRODUCTION AND GROVE ORGANIZATION STUDIES OF
FLORIDA CITRUS
Purnell Project 186 C. V. Noble, Zach Savage and Bruce McKinley
The process of closing the cost accounts which the citrus growers kept
for the fiscal year 1932-33 was completed. Duplicate copies of these ac-
counts were made and retained in this office for permanent record.
Each grower's completed accounts were returned, together with sum-
mary sheets giving costs and returns by kinds of fruit, maturity season
of fruit and age of trees. Also a comparison was shown between the
average costs and returns for the group and for the individual cooperator's
grove. A copy of the summary sheet for late grapefruit from 12 to 14
years of age is here shown as Table 1.
At the end of the 1933-34 accounting year each cooperator was visited
and the accounts for the year were closed on 32 groves with a total acreage
of 1184.15. At the same time, accounts were opened for the 1934-35
accounting year on these same 32 groves and four additional ones, rep-
resenting a total of 1255.15 acres of citrus.
The closing of the 1933-34 books has been virtually completed and tabu-
lations for summarization are in progress.








Annual Report, 1935 33

TABLE 1.-COSTS AND RETURNS FOR LATE GRAPEFRUIT, 1918 TO 1920
PLANTINGS*.

Average Your
SAll Groves Grove

Season ...................... .......... ....... ............... 1932-33 1932-33
N um ber of accounts ...................................................... 5
Age of grove (years) .................................................... 12 to 14
A cres per grove ......................................... ................... 10.29
Trees per acre ............................................................... 67
Grove value per acre ................................................... $592.42
Yield in boxes per acre .............................................. 272
Yield in boxes per tree ................................................ 4.07

Costs per acre:
Labor .......................................................... ......... $ 12.15
Supervision ..... --.-. ---.--. ............................ 10.62
Power and equipment .....................................-.... 6.98**
Labor, power and equipment not separated ....... 1.63***
Fertilizer ---------------.... ...........---- ....--- ..----........ --18.00
Spray and dust .......................................... ............. 1.98t
Taxes ..................--------- --- .......-..... ..-- ........- ......... 6.80
Interest on grove at 7% ........................................... 41.47
A ll other costs ............................... ....................... 4.38
Total costs per acre ......................................... ....... 104.01
Returns per acre ........................................... ...... 147.10tt
Profit per acre ......................... -........-- -- ------43.09

Costs per box .............................. .................. ......... $ .382
Returns per box .............................................................. .541
Profit per box ..................................... .............. ........ .159

Pounds of fertilizer per acre ..................................... 1227
Pounds of fertilizer per tree ..............-. ........... 18.36
Citrus cost of production investigations, Department of Agricultural
Economics, Agricultural Experiment Station, Gainesville, Florida.
** Only four groves had this cost averaging $8.75 per acre.
*** Only three groves had this cost averaging $4.06 per acre.
? Only three groves had this cost averaging $4.33 per acre.
ft Only four groves had returns for fruit which averaged $197.86 per acre
for 366 boxes of fruit.

A STUDY OF PRE-COOLING AND OF REFRIGERATION IN TRANSIT
AS AFFECTING COST OF MARKETING, QUALITY
AND PRICE OF CITRUS FRUITS
Purnell Project 235 A. H. Spurlock, Zach Savage and Bruce McKinley
All computations and adjustments necessary have been made on the
11,000 manifests of car-lot shipments of citrus reported last year. A series
of codes has been applied to facilitate transferring the data to punch cards.
Work has been delayed on this project for several months to secure
the services of tabulating equipment. Arrangements have been completed
with the Farm Credit Administration of Columbia, South Carolina, whereby
the data will be transferred from the individual car manifests to punch
cards in their offices. The punched cards will subsequently be sorted and
tabulated on the Hollerith Electric Sorting and Tabulating Machines at
Columbia.








Florida Agricultural Experiment Station


Two types of cards have been designed to carry the data. One card
will carry all charges for each service from the point of origin to market,
including selling charge. The other will carry the prices received for each
kind of fruit by sizes. The cards can be sorted to show point of origin,
destination, date shipped, date sold, method of shipment and preservation
in transit. The price cards will also show the grade, color and variety
of fruit.
It is expected that work toward completion of the tabulation and analysis
of these data will go forward at an early date. Present indications are
that the work at Columbia will start about July 20, 1935.

FARM TAXATION
Purnell Project No. 248 C. V. Noble
Inactive during 1934-35.

A STUDY OF ADJUSTMENTS IN FARMING REGIONS AND TYPE-
OF FARMING AREAS, FROM THE STANDPOINT OF
AGRICULTURAL ADJUSTMENT AND PLANNING,
INCLUDING SOIL CONSERVATION
P.urnell Project 262 C. V. Noble and Bruce McKinley
(in cooperation with Federal Project 1100, A.A.A. and B.A.E.)
Work on this emergency project started on May 1, 1935 and the primary
objective is to obtain better basic background data for use in connection
with the Agricultural Adjustment Administration program after 1935.
The work in this state may be classified as follows:
1. Historical Phase of Types of Farming in Florida. This work con-
sists chiefly of a comparative study of types of farming on a county basis,
using the U. S. Census of Agriculture-for 1910, 1920, 1925 and 1930 as
the background. Pertinent data of a comparative nature have been tabu-
lated and are in readiness for analyses.
2. A Reconnaissance Soil Survey of Those Portions of Florida That Have
Not Been Surveyed in Detail. One of the important factors delimiting type
of farming areas is the quality of soil. Since less than 25 percent of the
land area of Florida has been soil surveyed, it was considered essential
that at least some reconnaissance soil work be done in those areas where
the detailed studies had not been made. This work has been pushed for-
ward as rapidly as funds and personnel would permit and much progress
has been made, especially in northern and northwestern Florida. A new
soils map of the state will be prepared in the light of the information
gained from the reconnaissance work. This will aid in correcting the type
of farming map.
3. Citrus Freeze Damage. A careful checkup is being made of the
citrus freeze damage by counties during the past winter. Contacts are
being made with all known agencies that have made estimates, as well
as with other agencies or individuals who are in a position to give com-
petent estimates. These estimates from the many sources are at present
being brought together with the hope that a fairly reliable estimate may
be established. The heavy citrus freeze damage of the past winter may
have an appreciable effect upon the Florida type of farming map.
4. Livestock Estimates. Census data for livestock, particularly beef
cattle and hogs, have not been complete due, in part, to the fact that a
large proportion of these animals are on the open range and have no
connection with organized farms. Much more accurate statistics for cattle








Annual Report, 1935 35

have been obtained from the "dip count" in the cattle tick eradication work,
by counties.
5. Samples of Farm Organization. A tentative type-of-farming map
for the state was prepared in May on the basis of all available data and
other information at that time. This type map shows four general types
with 21 more specific types. After the map was prepared it was then
desired to go into as many of these type areas as possible and obtain a
representative sample of the business organization of farms in the area
to ascertain the accuracy of the type map at the present time. Eight
of the 21 type areas have been sampled during the past two months. Lack
of funds and personnel will not permit of further sampling, but eight
additional areas have been similarly sampled within the past 12 years
and the results of such sampling will be of value in the final analysis of
this project.
OTHER WORK
In May 1932 this Department published the results of "An Economic
Study of 249 Dairy Farms in Florida" in bulletin 246.
In the preparation of a manuscript entitled "Management of Dairy
Cattle in Florida", this Department cooperated with the Animal Husbandry
Department to the extent of furnishing some of the economic background
for Florida dairy herds as found in the study of the 249 farms. The
results of this cooperative study are incorporated in bulletin 274.








Florida Agricultural Experiment Station


AGRONOMY
Agronomy experimental work has progressed satisfactorily during the
year. Continued cooperation with the Forage Crops Office, U. S. D. A.,
has resulted in the securing and testing of much new forage crop material.
The cooperative pasture experimental work with the J. C. Penney-Gwinn
Corporation (now Foremost Properties, Inc.) has continued and is now
in its sixth year.
One press bulletin on a new cowpea, particularly adapted to Florida
and named "Suwannee," has been published and well over 1,000 samples
of seed of this cowpea have been distributed to interested farmers.
A number of new oats from South America and Australia, as well
as several well adapted local varieties, continue to show promise. These
oats are being tested against Fulghum and Appler, two most commonly
planted varieties, and seed supplies are being carefully developed.
Breeding operations with peanuts and field and sweet corn continue
to show exceedingly promising results.
Active pasture studies have involved: (1) Various fertilizer treatments
and their effect on yield and composition, (2) effect of cutting and fer-
tilizer treatment on yield, composition and growth behavior, (3) the effect
of frequency of cutting of pasture grasses on yield, growth behavior, com-
position and utilization of applied nitrates, (4) methods of sampling pas-
tures to obtain comparable yields of herbage, and (5) a comparison of
burned and unburned native pastures and improved pastures.
Crop variety, rotation and fertilizer experiments have continued to
show results of value in economical crop production.
The use of zinc sulfate as a corrective for white bud of corn and poor
growth in other field crops continues to show good results under certain
conditions. Residual effect of zinc sulfate is showing up favorably. Definite
zinc deficiency symptoms of various field crops are being carefully observed
and recorded.
New sugarcanes, developed through the breeding operations at the
Everglades Experiment Station, are being tested at Gainesville for re-
sistance to root-knot, mosaic and other troubles with the idea of selecting
kinds superior for syrup and forage purposes.
Land rested to native cover and land rested to planted cover and planted
to corn and peanuts during years of no rest as compared to land yearly
planted to corn and peanuts is yielding some interesting results in favor
of resting to native cover. No fertilizer and no special elements are applied
to these crops.
PLANT BREEDING-PEANUTS
State Project 20 Fred H. Hull and W. A. Carver
Selection was continued with crosses between varieties of common pea-
nuts and in crosses of common peanuts with the Nambyquarae and Rasteiro
peanuts from Brazil. The principal objectives are a dual-purpose variety
suited either to hogging off or harvesting for manufacture, a Jumbo type
which fills well in Florida, and a hay type.
The older hybrid selections consist of 286 plant rows in the 1935 breeding
plot. In addition there are 4,800 second generation plants of the cross
Spanish x Jumbo or Dixie Giant and about 700 from miscellaneous crosses.
Twenty-five new crosses were made in 1934 and the first generation is
being grown in 1935. Parent plants are being prepared in the greenhouse
for crosses of White Pearl and Virginia varieties. Such crosses have not
been made formerly.
The older hybrid strains which have become practically true-breeding
are being studied carefully as breeding stocks as well as for commercial use.








Annual Report, 1935


No yield test on peanut varieties was conducted in 1934 but a few of
the older hybrid selections were placed in a yield test in 1935 with a
number of commercial varieties.
Studies of the inheritance of about 20 characters have been made in
the older crosses, particularly between Spanish and Jumbo. During the
past year the inheritance of required rest period of seeds, seed shape, seed
coat color, yellow seedlings, and brachytic dwarf has been analyzed and
a report prepared. Data on the other 15 characters will be analyzed as
soon as possible.
PASTURE EXPERIMENTS
Hatch Project 27 W. E. Stokes and Geo. E. Ritchey
I. COMPARISON IN GRAZING TESTS OF THE PASTURE VALUE
OF DIFFERENT GRASSES ALONE AND IN MIXTURE
The grazing phase of this experiment was closed with the 1933 records
and a complete report of the work has been prepared for publication. The
pastures are being maintained for further studies. In 1934 a study of
methods of sampling grasses for herbage yield was conducted on them.
II. THE INFLUENCE OF VARIOUS FERTILIZER FORMULAS ON
THE YIELD OF PASTURE GRASSES
Five years' work has been completed on this study. Twenty-one differ-
ent fertilizer formulas were used on 76 plots. Yield records of the grasses
were taken monthly. Results were similar to those of other years. The
use of phosphate or of potash alone has had little or no effect on the grass
yield. Plots which received nitrogen, however, have shown a marked
increase in yield. Those which were limed have shown a decrease in yield
except when treated with potash.
III. COMPARISON OF NATIVE AND IMPROVED PASTURES;
COMPARISON OF BURNED AND UNBURNED NATIVE
PASTURES FOR BOTH NINE AND TWELVE MONTHS OF
GRAZING, AND A COMPARISON OF METHODS OF LAND
PREPARATION PREVIOUS TO SEEDING IMPROVED
PASTURES
This experiment is in its sixth year. Improved pastures continue to
yield more pounds of beef per acre (live weight) than native pastures.
Burned native pastures have yielded more beef per acre than unburned
pastures. The pastures are still better where the best land preparation
was given previous to seeding. This phase of the pasture experiment is
in cooperation with the Animal Husbandry Department.
IV. PASTURE PLANT ADAPTATION TESTS
Two acres have been set aside and planted to various grasses and
legumes to study their palatability, habits of growth and general adapta-
bility to grazing conditions.

CROP ROTATION STUDIES
Hatch Project 55 W. E. Stokes, J. P. Camp and G. E. Ritchey
I. CORN, COTTON, CROTALARIA AND AUSTRIAN PEAS
This experiment has been in operation since 1930. The results in 1934
were quite similar to those of previous years. A very decided increase
in yield of seed cotton has been obtained. The greatest increase in yield


0








38 Florida Agricultural Experiment Station

of cotton due to the rotation was obtained from the plots growing corn,
crotalaria and cotton in the series.
The corn continues to show less difference than cotton between the
plots which are rotated and those continuously planted.
The yield of the winter cover crops continues light, averaging only
642 to 612 pounds of dry matter per acre. The ones used in this test are
poorly adapted to the light sandy soil on which this experiment is located.
II. CORN AND CROTALARIA
In the spring of 1934 a series of plots were planted to Crotalaria inter-
media, C. spectabilis and C. striata. Others were left to grow native
vegetation. All plots were triplicated. The material which had grown
on the plots was plowed under in the spring of 1935 and all plots were
planted to corn.
It is planned to allow the three species of crotalaria and the native
growth to grow on alternate years with corn, thus in effect, allowing the
land to "lay out," growing the different plants every other year.
III. CORN AND PEANUTS ROTATING WITH CROTALARIA AND
WITH NATIVE COVER CROPS
Since the spring of 1933 this phase of crop rotation work has been
under way. Continuous corn and peanuts have shown less satisfactory
yields than corn and peanuts rotating alternate years with crotalaria or
than corn and peanuts rotating alternately and every third year with
native cover crops. Since the land on which this experiment is conducted
normally produces considerable "white bud" corn, it has been interesting
to note that the corn following the native volunteer cover crop has shown
markedly less white bud than continuous corn or corn following the planted
cover crop of crotalaria. No fertilizers or special elements are used in
this experiment.

VARIETY TEST WORK WITH FIELD CROPS
Hatch Project 56 W. E. Stokes, G. E. Ritchey and J. P. Camp
SOYBEAN VARIETY TEST
Ninety-nine recent introductions of soybeans were planted in row tests.
Only two made growth of any promise. Both resembled the Laredo in
habits but neither produced well developed seed. One planting was at-
tacked by root-knot nematode.
COWPEA VARIETY TEST
The cowpea variety previously referred to as F. C. No. 04589 has been
officially named "Suwannee." It continued to be outstanding in yield of
forage and ability to hold its leaves longer than other varieties. One
thousand packages of seed were distributed to farmers and growers of
the state in the spring of 1935, and about 12 acres were planted at the
Experiment Station for seed increase.
The Suwannee cowpea was planted in competition with the following
varieties in 1934: Brabham, Iron, Potomac, Columbia, Arlington, White
Queen, Conch, Victor F. C. 20074, Progressive White and the Cajung.
Of these the Cajung was the only pea which approached the Suwannee
in growth. The Cajung, however, sheds its leaves early in the season and
the Suwannee continues to grow and hold its foliage.








Annual Report, 1935


SUGARCANE VARIETY TEST
Over 1,100 sugarcanes have been under observation. In the fall of
1934 70 were selected for further observation and study with a view to
finally weeding out all other than the most desirable syrup and forage kinds.
OAT VARIETY TEST
Fulghum, Appler, Suwannee County Black Hull (Goff) and several
new oats from South America and Australia, as well as a large number
of strains and selections from the Cereal Office, U. S. D. A., are under
observation with a view to finding oats as good as or better yielding than
Fulghum and Appler and much more resistant to rust. A number of the
newer oats under observation show promising resistance.
PEANUT VARIETY AND STRAIN TEST
Standard varieties, as Florida Runner and Spanish, are this year being
compared with certain of the older, more stable and desirable hybrid pea-
nuts. (See Project 20.)
CORN VARIETY TEST
Both field and green corn (roasting ear types) variety tests are being
conducted as a necessary part of the broad breeding operations with corn.
(See Project 105.)

COVER CROP AND GREEN MANURE STUDIES IN CITRUS GROVES
State Project 83 W. E. Stokes and J. H. Jefferies
See report of the Citrus Experiment Station.

GREEN MANURE STUDIES
Hatch Project 98 W. A. Leukel and G. E. Ritchey
This experiment, with certain phases of it in cooperation with Chemistry
and Soils Project 96, involves field and phytometer trials principally with
the three most promising species of Crotalaria striataa, spectabilis and
intermedia) as green manure crops. In the field trials corn and in the
phytometer trials Sudan grass and oats are the indicator crops. The
purpose is to get information on the comparative value of certain green
manure crops in crop production.
The comparison of the green manure crops in the field trials is of
course on the basis of actual field yields of the green manure crops and
field yields of the indicator crop, while in the phytometer trials the fol-
lowing bases are used: (a) same quantity of dry material, (b) same
quantity of nitrogen, and (c) actual field yields of green manure crops,
respectively.
The experiment has not run long enough to draw definite conclusions;
however, it is quite evident that green manure crops are of considerable
value in crop production and at the same time it is apparently true that
there are a number of factors responsible for the specific value of any
green manure crop.

IMPROVEMENT OF CORN THROUGH SELECTION AND BREEDING
Purnell Project 105 F. H. Hull and W. A. Carver
Field Corn:-Breeding by selection within inbred lines has been continued
with nearly all of the 500 lines noted in the last report. Tests of the
prepotency of the lines in crosses with Whatley Prolific have also been
continued. From such tests a few lines were selected in 1934 and combined


0








Florida Agricultural Experiment Station


into 70 single crosses. Approximately 200 double crosses were made from
them in 1935 and 300-400 new single crosses produced. The first tests
on double crosses will be made in 1936.
Correction of the principal faults of established varieties with pre-
potent inbred lines is an untried method of corn improvement which is
being investigated. Whatley Prolific has shown in numerous tests in
central and northern Florida 25-30% greater yields than native strains,
but it lacks weevil resistance. A foundation stock has been prepared
whose ancestry is 75% Whatley. The other 25% is composed of lines
which produce weevil resistant hybrids with Whatley. This stock was
increased and distributed in small lots to 20 farmers from Marion to
Escambia counties. Crosses of 200 inbreds on Whatley Prolific are being
tested at the North Florida Station.
The extreme resistance of Cuban Yellow Flint to pests and its adapta-
bility to the sub-tropical climate of southern Florida is very desirable but
the variety is low yielding. A foundation stock composed of 75% Cuban
Yellow Flint and 25% of several inbred lines prepotent in increasing the
yield of Cuban is being produced. Thirty inbreds were crossed with Cuban
in 1934. The hybrids are being grown in 1935 at the Everglades Experi-
ment Station, at Weirsdale, and at Gainesville. Forty more inbreds were
crossed with Cuban in 1935.
Variety tests at Gainesville included 21 entries. A test at the North
Florida Station consisted of 22 entries, and at the Everglades Station a
test was made with 22 entries planted on four different dates. Records
were taken on yield, prolificacy, weevil damage, soundness, lodging, and
other characters. Results and recommendations were distributed to seeds-
men, county agents and others. Variety tests at the three stations are
being continued in 1935 and seed was furnished to two county agents for
cooperative tests.
Sweet Corn:-A new variety, Suwannee Sugar, was released in small
quantities to growers and seedsmen. Its ancestry is three-fourths Southern
Snowflake and one-fourth Long Island Beauty. It is a true sweet with
good table quality. The plant type is a little smaller and earlier than
Snowflake. The ears are large and the husk protection against worm
damage very good.
The work of building sweet strains of the dent roasting-ear corns,
Snowflake, White Dent, Dubose, Tuxpan, Oklahoma Silvermine, Trucker
Favorite and Hickory King was advanced another generation. An attempt
to gain an additional generation in this work with a winter planting near
Lake Okeechobee failed due to a freeze in December. Sweet Dubose and
Sweet Snowflake have been recovered and both found to be of poor table
quality in general. Both varieties were variable in sweetness and tender-
ness, with an occasional ear both sweet and tender. Consecutive sibbing
was practiced in each variety and the second ears of each plant were tested
for quality. In those cases where two plants were crossed and both were
later found to be sweet and tender the seed were saved to continue the
variety.
No yield tests of roasting ear corns were made in 1934. The 1935 test
includes four new varieties of sweet corn from this station, three from
the Texas Station, two from the Georgia Station and one from the Porto
Rican Station at Mayaguez. All of these new sweet varieties are of South-
ern type and very different from the commercial (Northern type) varieties
of sweet corn hitherto available. The test also includes a number of com-
mercial sweet varieties and popular dent roasting ear varieties grown
in Florida.
A survey of quality factors during the past two seasons has indicated
that none of the new sweet varieties already available or being built by







Annual Report, 1935 41

converting roasting ear corns to sweet type are likely to possess the ex-
tremely high table quality of some of the recent Northern selections. Some
of them, particularly Sweet Hickory King, promise to equal the average
of commercial sweet corns. However, a combination of the best table
quality found among the Northern strains with Southern plant type seems
a worthwhile objective. Breeding work toward that end was begun in
1934 with a cross of a high quality strain and the largest Southern type
available. The first hybrid generation was grown in 1934 with sib-pollina-
tion to produce the second.

CROP ADAPTATION STUDIES
Hatch Project 107 W. E. Stokes and Geo. E. Ritchey
The work of the Forage Crop Nursery was continued, over 400 plantings
having been made in 1934 for observation and study. A goodly number
were new and were planted in 1934 and 1935 for the first time. Several
native grasses and legumes have been collected and are being studied under
cultivated conditions. A number of grasses and legumes are showing
promise for pasture forage and green manure purposes.
Several grasses have been planted in a wooded area, thus making it
possible to study their adaptability to shaded fields.
The use of rabbits as an indicator for toxicity and palatability of the
newly introduced plants has proved satisfactory, and they are being used
continuously for such studies.
FERTILIZATION OF PASTURE AND FORAGE GRASSES
Hatch Project 120 W. A. Leukel and J. P. Camp
The results of work on the effects of nitrate fertilization and frequent
cutting of pasture grasses have been published during the year in Bulletin
269.
FERTILIZATION OF NAPIER GRASS
Fertilization of Napier grass was continued. A complete 4-4-4 fertilizer
was applied to the previously fertilized plots at the rate of 600 pounds
per acre. Barnyard manure was again applied on one-third of the plots.
The fertilized and manured plots made vigorous growth during the early
part of the season, but the plants in all areas succumbed to disease later
in the season and comparative yields were not significant. However, in
all plots some plants appeared to be immune to disease. Selections are
being made from these plants for disease resistance.
These studies have been extended to a higher yielding strain of Napier
grass, using nitrate of soda and cyanamid as sources of nitrogen with and
without the addition of zinc. Weights of the crowns or lower plant parts
are being recorded and the organic foods stored therein determined. These
factors are being correlated with yields of forage. In general, thus far,
the stored foods in the lower plant parts appear to be directly correlated
with the silage yields on a quantity basis.
EFFECTS OF VARIOUS RATES OF NITROGEN FERTILIZATION
FROM DIFFERENT SOURCES OF NITROGEN ON
PASTURE GRASSES
To obtain more definite information of the effects on pasture grasses
of larger applications of nitrogen from different sources, separate areas
of Bahia grass are being subjected to different nitrogen treatments. Plots
in one series are being treated with nitrate of soda at the rate of 500
pounds of nitrogen per acre and another series at the rate of 1,000 pounds







Florida Agricultural Experiment Station


per acre. These treatments are being applied during the growing season
in nine monthly aliquots. Similar series of plots are being treated in like
manner, using ammonium sulfate and cyanamid. Some differences have
been noted in the effects of different nitrogen fertilizers applied on grass
during dry weather.

COMPOSITION STUDIES ON FIELD AND SWEET CORN
Laboratory studies were made on the carbohydrate fractions of Southern
Snowflake field corn and a sweet strain of Snowflake. Sweet Snowflake
was developed by crossing Snowflake to Long Island Beauty sweet corn
and following with three back-crosses to Snowflake. The pure sweet type
was selected after the last back-cross. The greatest difference between the
sweet and field strains in carbohydrate fractions was noted in the dextrins
rather than in the sugars.
To what extent the sweetness of corn is affected by sugars and in what
way dextrins may affect this factor in corn cannot be determined from
the data available. Further studies on this phase of the work are con-
templated. The kinds of mono-saccharides and di-saccharides in the corn
may lead to more definite conclusions. Certain mono-saccharides are known
to have a sweeter taste than others. This factor combined with the per-
centage and quantity of different higher carbohydrates may in some way
produce more desired results.

NITROGEN FRACTIONS IN CORN TREATED WITH ZINC AND
CORN WITHOUT ZINC TREATMENT
A preliminary laboratory analysis was made on field corn affected with
"white bud," and corn not so affected due to applications of zinc. The
appearance of the affected plants and their growth behavior indicated a
probable lack of nitrogen absorption. Results of the analysis are shown
below.
TABLE 2.-GREEN AND DRY WEIGHT AND DIFFERENT FORMS OF NITROGEN
IN 10 AVERAGE SIZE CORN PLANTS GROWN UNDER DIFFERENT SOIL TREAT-
MENTS AND CUT DURING THEIR VEGETATIVE GROWTH PERIODS.
(Treated with Zinc)

a Total nitrogen



2170 290 13.36 0.526 2.164 2.254 0.090 0.435 0.165 2.69 7.80


(No Zinc Treatment)

630 100 115.87 0.70 1.69 11.878 0.188 0.512 0.113 2.39 2.39

Slight differences were noted in the different forms of nitrogen in the
vegetative material from the corn plants treated with zinc and the plants
not so treated. Most striking difference was found in the quantity of
green and dry material and of nitrogen. Since nitrogen is often a limiting
factor in growth, it appears the zinc might in some way be associated
with the availability of this element for plants.







Annual Report, 1935


COMPOSITION STUDIES ON PEANUTS
Composition studies are being made on different strains and varieties
of peanuts in connection with breeding experiments on these plants. It is
possible that results of breeding tests may be reflected in the composition
relations of the nuts. Results thus far are not complete.

DATE OF SEEDING AND PHOSPHATE REQUIREMENTS OF WINTER
LEGUMES AND THEIR EFFECT UPON SUBSEQUENT CROPS
State Project 153 J. D. Warner
This project has been inactive during the year.

RATIO OF ORGANIC TO INORGANIC NITROGEN IN MIXED
FERTILIZER FOR COTTON
State Project 159 J. D. Warner
This project has been inactive during the year.

CORN FERTILIZER EXPERIMENTS

State Project 163 J. D. Warner, W. E. Stokes and J. P. Camp
This project has been in operation since 1930 and has been conducted
:at the Experiment Stations and cooperatively with farmers and county
agricultural agents over central and northwest Florida.
The objectives are (1) to determine the effect of nitrogen, phosphorus
and potassium singly and in various combinations and amounts on the
yield of corn, (2) to determine the relative efficiency of organic and in-
organic nitrogen in corn production, (3) to determine the relative efficiency
of various sources of nitrogen in corn production, and (4) to determine
the effect of certain less abundant elements such as zinc when used in
.connection with nitrogen, phosphorus and potassium on the yield of corn.
Results thus far, as in past years, indicate that nitrogen is usually the
most limiting element in corn production. This element has consistently
stimulated yield more than any other in a complete fertilizer. The results,
however, also indicate that on certain soils phosphorus and potassium in
addition to nitrogen are necessary for maximum yields.
Generally speaking, the soils of central Florida do not seem to require
the amounts of phosphorus and potassium needed by the soils of northwest
Florida for corn production. The inorganic sources of nitrogen seem to
be as efficient as the organic sources on the soils of northwest Florida,
while the organic sources of nitrogen sometimes gives slightly better
results on the lighter soils of central Florida. Price of the two sources
of nitrogen, however, should largely determine the one to use, since the
difference in their relative efficiency on these lighter soils has been very
:slight.
There seems to be little or no difference between the various sources
of inorganic nitrogen for corn. In some cases sulfate of ammonia and
leunasalpeter have consistently led, but in other instances this has not
been true. Tests must be continued on each of the principal soil types
over a number of years before reliable results are obtained.
The use of zinc sulfate, in combination with nitrogen, phosphorus and
potassium, for corn apparently has not increased the yield of corn except
in cases where the soils normally produce chlorotic "white bud" corn.







Florida Agricultural Experiment Station


A STUDY OF CROTALARIA AS A FORAGE CROP
State Project 174 W. E. Stokes and G. E. Ritchey
In the spring of 1934 about 23 acres were seeded to Crotalaria intermedia.
The crop was used for several studies which included rate of planting,
date of planting, method of planting, method of hay making, and several
other minor tests.
The crotalaria grown in these tests was delivered to the Department
of Animal Husbandry of this Station. Four small laboratory silos were
filled with the crotalaria which had been cut at four different stages of
development for palatability trials, and another 30-ton silo was filled for
feeding trials with cattle. Feeding results are reported by the Department
of Animal Husbandry.
I. DATES OF PLANTING CROTALARIA INTERMEDIA
Plantings of C. intermedia were made every 15 days, beginning February
17 and ending July 15.
The portions of the field which were planted April 3 and April 15 made
the best growth. Plantings made before April 1, and after May 1, were
much smaller and less vigorous than those made in April. All plots bloomed
and ripened seed at approximately the same time regardless of when they
were seeded. That planted July 15 grew to a height of about 2 feet but
produced a fairly good crop of seed.
II. RATE OF SEEDING CROTALARIA INTERMEDIA
Three methods of varying the rate of seeding were used in this study.
One method was to vary the amount of seed per row, keeping the width
between rows constant. Another was to vary the width between the rows
and keep the rate of seeding per row constant. The third method was to
broadcast on plots using different rates on each plot.
Varying Spacing Between Rows
Seed was sown in rows spaced 2% feet apart, 4.2 pounds per acre;
3 feet apart, 3.5 pounds per acre; 3% feet apart, 3 pounds per acre; and
4 feet apart, 2.6 pounds per acre.
The yields from the plots sown 2%, 3 and 3 feet apart were about
the same, varying from 1.38 to 1.43 tons of oven-dry material per acre.
The yield from the plots sown 4 feet apart was lowest, averaging 1.01 tons
oven-dry material per acre.
The rows sown 2% feet and 3 feet apart produced the finer stems and
fewer grasses and weeds than those sown more thinly. However, these
rows were too close together for efficient cultivation.
Varying the Rate Per Row
The seed in this test was sown in rows 3 feet apart at rates of 3.5;
5.2; 7.0 and 10.4 pounds per acre. The yield of oven-dry material increased
from .789 tons per acre on the plots sown at the rate of 3.5 pounds with
each increase in rate of seeding to 1.234 tons per acre on the plots seeded
to 10.4 pounds.
The plots which were seeded heaviest produced a finer stemmed product
but there was a heavier dropping of the lower leaves. The plots seeded
at the medium rates produced a good quality of material which suffered
less dropping of the leaves and produced plants with medium fine stems.
Varying Rates of Seeding in Broadcasted Plots
Plots were prepared and seeded broadcast to Crotalaria intermedia
at the rates of 4, 8 and 12 pounds per acre.







Annual Report, 1935 45

The highest yield was obtained from the plots seeded at the rate of
8 pounds per acre. There was a heavy dropping of leaves from the plants
seeded at the rate of 12 pounds per acre. The crotalaria grown on the
plots sown at the rate of 4 pounds per acre was much coarser stemmed
and was not thick enough on the ground to prevent the growth of weeds
and other plants.

III. STAGE OF CUTTING CROTALARIA INTERMEDIA
Crotalaria intermedia was cut at the following stages of growth and
used for silage and hay: pre-bud, bud, bloom and pod stages. The crota-
laria cut at the pre-bud stage was waist high, tender and succulent. The
yield was very low but it produced a product of high quality. A second
growth was obtained which produced a fair seed crop.
Cutting at the bud stage produced a high grade product, more stemmy
and with coarser stems than that cut earlier but yielded over three times
as much.
The crop cut at the bloom stage yielded about 25% more than that
cut at the bud stage, but was coarser and contained more fiber. The plants
cut at the pod stage were coarse, fibrous, and stemmy.
This year's results would seem to indicate that the C. intermedia cut
in the bud or early bloom stage of development will produce the largest
yield of good quality hay or silage.

IV. METHODS OF HAY MAKING

A portion of the crotalaria cut at each stage of growth in the date
of cutting study was used. A portion of each cutting was bound into
bundles and shocked, a portion was dried in the swath and another portion
was spread out on drying floors to cure.
In all stages of growth a good hay was produced when dried on the
floors of the drying shed. The best quality was that cut at the pre-bud
stage, but the yield was very low. The bud-stage cutting produced a good
quality and high yield of hay.
In all cases the shocked crotalaria dried well but molded in the center
of the bundles. The hay dried in the swath cured well but bleached some.
The hay was delivered to the Animal Husbandry Department to feed
to mules, and results of the feeding test are reported by them.

A STUDY OF CHLOROSISS" IN CORN PLANTS AND OTHER
FIELD CROP PLANTS
Adams Project 220 R. M. Barnette and J. P. Camp
Applications of zinc sulfate in the drill before planting have continued
to prevent the development of the chlorosis of corn known as "white bud."
This material has been used at various rates from 5 to 60 pounds per
acre, the highest rate being very little if any better than the lowest.
Applications of 15 to 20 pounds per acre which were made to 1934 corn
plots are plainly helping the 1935 crop, or in other words showing a bene-
ficial residual effect.
Zinc deficiency symptoms have been recognized on certain other field
crops; namely, cotton, cowpeas, velvet beans, and Pearl millet. Although
no distinctive symptoms have been found on peanuts, sugarcane, Napier
grass and crotalaria, these, as well as the above crops, have responded
favorably to zinc sulfate applications.
Further information on this project will be found in the report of the
Department of Chemistry and Soils, this being a cooperative project.


I







46 Florida Agricultural Experiment Station

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
Observational and laboratory studies on the root growth behavior of
pasture plants are being continued. As previously reported, new growth
in spring appears to be produced at the expense of previously stored foods
in the.old plant. When the new plant is well established with a new root
system the old stolon with its root system deteriorates. In the case of
frequently cut grasses the plant of the previous season appears to possess
more embryonic tissue and sends out new growth from a greater portion
of its system and persists longer. Unlike those of many other plants,
the old stolons appear to become exhausted of food materials or die off in
sections generally farthest removed from the newly growing parts.
Root growth appears to be retarded or slow while plants are in a vege-
tative growth condition. At or beyond the reproductive stage root growth
increases greatly while vegetative growth is retarded or ceases.
The larger quantity of nitrogen taken up by grasses during the vege-
tative growth periods and when plants have a smaller and less extensive
root system appears to be correlated to some extent with the ability of
the plant to reduce nitrates or its reducase activity. This reducase activity
again appears to be associated with the availability of phosphorus and
potassium.
MISCELLANEOUS
PRELIMINARY STACK SILO EXPERIMENTS
Surplus cane from the sugarcane variety and line trials has been used
in stack silo tests. The silage is piled on the ground in stacks and covered
with approximately two feet of dirt. Various sizes of stacks are under
observation. This method of preserving crops as silage has the advantage
of very low first cost and mobility of location, but the proportion of spoiled
silage generally runs considerably higher than with upright wood, concrete,
tile or metal silos or even well constructed trench or pit silos.

COMPARATIVE PRODUCTION OF SEVERAL SILAGE CROPS
GROWN AT RELATIVELY HIGH FERTILITY LEVELS

In 1934 and 1935 corn followed by cat-tail millet, sorghum, Napier
grass and Cayana sugarcane were grown on like soil and harvested and
weighed at the silage stage in order to arrive at comparative yields of
these crops for silage purposes.
Corn (Whatley Prolific) produced 12,024 pounds green weight per acre
and was followed by a crop of cat-tail millet which produced 10,482 pounds
per acre or a total of 22,506 pounds per acre. Napier grass, two cuttings,
produced 60,167 pounds per acre. Texas Seeded Ribbon Cane Sorghum,
two cuttings, produced 37,969 pounds per acre, and Cayana sugarcane
produced 76,782 pounds per acre.
Such yields are not possible on the light sandy soils of the Experiment
Station except during very favorable seasons and with rather liberal
fertilization, both of which prevailed in 1934.
The same crops are being grown in 1935 but the season thus far has
not been as favorable as last year.







Annual Report, 1935 47

CHUFA FERTILIZER AND SPACING TEST
Some information on the fertilization and spacing of chufas seemed
desirable, consequently a planting was made July 21, 1934, carrying two
complete fertilizer (5-5-5 formula) rates and two spacings. The results
of this test are given in the accompanying table.
TABLE 3.-CHUFA FERTILIZING AND SPACING TEST.
Fertilizer Treatment I Pounds Air-Dry Chufas per Acre
Lbs. fertilizer per acre I 12" 6" Average yield of both
(5-5-5 formula) Spacing Spacing Spacings

None............................. 1,398 1,538 1,468
300........... .................... 1,577 1,575 1,576
600........ ....................... 1,566 1,594 1,580
Average.......................... 1,519 1,571 1,545


0







Florida Agricultural Experiment Station


ANIMAL HUSBANDRY
Herds of dairy cattle, beef cattle and swine are maintained to furnish
experimental animals for projects dealing with these classes of livestock.
Records are kept regarding the breeding, feeding and management of these
animals, and other valuable records of milk production in the dairy herd,
breeding efficiency and mineral requirements of all herds are obtained.

DAIRY HERD
The dairy herd consists of 67 registered female and three registered
male Jerseys. Seven cows completed their period of usefulness during
the past year and were assigned to State Project No. 140 for weights
and measurements of organs.
Feeding and management practices have been continued as uniformly
as possible, so that the records may be comparable for studies of heredity
and nutrition as related to dairy cattle. Common salt, feeding bonemeal
and "salt sick" mineral (salt-iron-copper) have been available to the herd,
the consumption being tabulated monthly. Detailed records of reproduc-
tion have been kept for each animal. Close attention has been given to
reproduction, and the breeding efficiency has improved during the past year.
The daily milk records are reasonably complete back to 1917. A large
part of these records have been assembled and studied during the past
six years with relation to practical management of dairy cattle. The De-
partment of Agricultural Economics has obtained much valuable informa-
tion with regard to the dairy herds of the state. Facts from these two
sources were combined cooperatively, and published during the year as
Bulletin 274. Parts of the Station records of scientific interest are appear-
ing as technical papers in the Journal of Dairy Science.
The first two heifers by Sophie 19th's Victor 81st 331031 calved during
the year. Their milk production in the first lactation is a decided increase
over that of their dams. Floss Duke's Count 357288, junior herd sire, was
credited with his first heifer calf. Both of these bulls were donated to
the Experiment Station by W. R. Kenan, Jr., from his Randleigh Farm
herd in New York state.
Three Jersey heifers purchased last year from Oakwood Farm in North
Carolina have freshened, and are milking satisfactorily on Register of
Merit test.
All heifers are placed on Register of Merit test during the first lactation,
and again at five years of age, to measure the transmitting ability of the
various families within the herd. A number of excellent records are in
progress. Three cows qualified for the Register of Merit with mature
records during the year. These are as follows:
Florida Fontaine Marie 839772 10,391 lbs. milk, 5.41%, 562.41 lbs. fat, AA.
Stockwell's Majesty Sue 792759 7,127 lbs. milk, 5.76%, 410.65 lbs. fat, AA.
Florida Reception Madam 839773 8,089 lbs. milk, 5.04%, 407.63 Ibs. fat, AA.
Tests for tuberculosis and Bang's disease continued negative.

BEEF CATTLE HERD
The beef herd consists primarily of native cows obtained from ranges.
These are bred to registered Hereford bulls and their grade heifer calves
are retained in the herd as foundation females. The grade bull calves
are castrated and used in feeding trials. A small group of four registered
Hereford heifers comprise the present herd of purebred beef cattle.
Birth weights and rates of growth of all calves are recorded. During
the winter months the herd is divided into two lots for the purpose of







Annual Report, 1935 49

conducting studies in wintering beef cattle. The cattle are kept on im-
proved pasture during the grazing season. Ten acres have been sown to im-
proved grasses during the past year, which will add greatly to the available
grazing area.
SWINE HERD
Studies in herd management, feeding practices, and control of parasites
are conducted with a purebred herd of swine. The herd furnishes "feeder"
shotes for use in pork production projects. Experiments to determine
the feeding value of such crops as corn, peanuts and sweetpotatoes are
being conducted. Spanish peanuts and early maturing varieties of corn
are used in fattening the spring farrowed pigs for the early fall market.
Runner peanuts and sweetpotatoes are used in fattening the early fall
farrowed pigs. All field crops used for fattening experimental shotes are
"hogged off" in the field.
It has been found practical to control parasites in swine by keeping
the brood sows and pigs at all times in fields that have been planted to
some grazing crop.
POULTRY INVESTIGATIONS
Projects on feeding and management of chicks, laying hens and turkeys
have been continued during the past year at the West Central Florida
Experiment Station, (Chinsegut Hill), Brooksville, in cooperation with the
Animal Husbandry Division, Bureau of Animal Industry, U. S. D. A.
Three projects at the Florida National Egg-Laying Contest at Chipley
have been continued during the past year. Work has been continued in
cooperation with the Department of Home Economics on quality of eggs
and factors affecting quality.

THE NUTRITION LABORATORY
Increasing demands have been made during the past year upon the
nutrition laboratory for analytical work in connection with studies on
mineral deficiencies and with samples collected from feeds used in feeding
trials with dairy cattle and steers. Nearly 300 new feed samples have
been taken for complete proximate and mineral analyses during the past
year. Phases of work represented include the ensilability of Florida for-
ages, efficiency of the trench silo, comparison of silages for fattening
steers, comparison of Crotalaria intermedia silage with alfalfa hay for
milk production, digestibility of Florida feeds, and samples from the studies
of deficiencies of feeds used in cattle rations.
Forage samples from ranges where cattle show the condition known
as "paces" were taken at four stages of growth and prepared for special
mineral analyses.
Bone samples were taken from cattle condemned during the summer
of 1934, when cattle were moved from certain ranges in the Kissimmee
River valley because of flood conditions. Other bone samples were taken
from calves in the Everglades showing symptoms of deranged mineral
metabolism.
Milk and tissue samples from healthy cattle, as well as those showing
some of the recognized mineral deficiencies, were taken. Over 100 have
been prepared for quantitative determination of their mineral content.
Samples of feeds and feces from digestion trials conducted in 1934 have
been analyzed, computations made, and results incorporated in Bulletins
275 and 279. Digestible nutrient contents of five feeds not previously
studied were determined in these trials.







Florida Agricultural Experiment Station


Hemoglobin determinations are being made weekly on the blood of all
experimental animals. Calcium and phosphorus contents of the blood of
some of the experimental animals have been determined.

THE ETIOLOGY OF FOWL PARALYSIS (Neurolymphomatosis
Gallinarum Pappenheimer)
State Project No. 119 M. W. Emmel
Intra-yolk sac injection of 0.2 and 0.1 c.c. of a suspension of Salmonella
aertrycke in baby chicks resulted in a septicemic disease. In such chicks
hemocytoblastosis was evident in blood smears taken shortly before death
which occurred in two to eight days. Suspensions of various densities
of 24-hour cultures of S. aertrycke administered in repeated intravenous
injections over varying periods of time to chickens 12 weeks of age re-
sulted in hemocytoblastosis, fowl paralysis, myeloid leucosis, erythroleucosis,
"light" and anemia. Lymphocytoma occurred as a complication in some
cases. It was impossible to obtain positive cultures of the causal micro-
organisms on nutrient agar plates when the plates were inoculated with
smears from the tissues of birds that had died showing evidence of any
of the above-mentioned conditions.
Hemocytoblastosis developed in at least seven days after the intravenous
injection of S. aertrycke and persisted throughout the incubation period
in those cases that developed fowl paralysis, myeloid leucosis, erythro-
leucosis, "light" or anemia. Birds often recover from severe cases of
hemocytoblastosis. Age is an important factor in resistance; it was neces-
sary to expose yearling hens to twice the number of S. aertrycke micro-
organisms as 12-weeks old birds to obtain comparable results. The incu-
bation period of fowl paralysis induced by repeated injections of S. aertrycke
was from 11 to 147 days, of leukemia from 27 to 253 days and of anemia
and "light" from 12 to 31 days. Results indicate that the number of or-
ganisms entering the blood stream, their rate of entrance, and the period
over which they enter are important factors in determining various patho-
logic manifestations of the disease.
Experiments are in progress to determine why fowl paralysis develops
in some instances and leukemia in others.
Since experiments indicate that fowl paralysis and leukemia are caused
by the same group of organisms, this project will hereafter be combined
with State Project No. 251.

DEFICIENCIES IN FEEDS USED IN CATTLE RATIONS
Purnell No. 133 R. B. Becker, W. M. Neal and P. T. Dix Arnold
Analyses of 21 mineral soils on which cattle become "salt sick" and of
17 "healthy" range soils showed that the former contained less than one-
third as much clay and silt, a third as much copper and only about one-
fifteenth as much iron as did the latter soils. This phase of the investi-
gation was cooperative with Dr. 0. C. Bryan of the instructional division,
College of Agriculture, who published the findings in the Journal of the
American Society of Agronomy, 27: 120-127.
Natal grass hay grown on deficient soil has been used in all controlled
feeding trials. Four steers were used in a digestion trial on this hay
in which it was found to yield 48.3 percent of total digestible nutrients.
It is a low protein hay. Data from this digestion trial appear in Bulletin
279.
Shortages of iron and copper are related to reproduction in cattle, as
shown by work in progress. A part of the accumulated records were







Annual Report, 1935 51

assembled and presented briefly before the Southern Section, American
Dairy Science Association.
Both nutritional anemia ("salt sick") and phosphorus deficiency were
observed during the year in the autopsies of cattle condemned during the
flood relief work of the United States Department of Agriculture.
Addition of calcium (as bonemeal) to low-calcium rations permitted
the cows to use this element for milk production. A summary of 218
lactations on low-calcium rations showed an average production of 4,856
pounds of milk, and with 73 lactations on the supplemented rations, 7,092
pounds of milk. This verifies earlier observations that lack of calcium
may limit milk production. These records are computed to a uniform age
basis, hence are slightly higher than actual records at different ages.
Forages and soils were collected during the fiscal year from ranges
on which cattle have "paces". These samples await spectrographic exam-
ination.
The nutrition barn was remodeled during the year, following its use
for digestion trials. Five calves are under controlled feeding in studies
of the relationship of iron and copper supplement to nutritional anemia.
Cow No. 386 was continued on a marginal level of iron and copper, as
shown by her condition. Her fourth calf was dropped during the year.
With all of these animals, weekly determinations of hemoglobin are being
made.

COMPARISON OF VARIOUS GRAZING CROPS WITH DRY LOT
FEEDING FOR PORK PRODUCTION
Hatch Project No. 136 W. W. Henley
Previous work has shown the practicability of using grazing crops for
fattening hogs in this state. These crops are "hogged off" in the field.
Spanish peanuts, corn, and sweetpotatoes were used as grazing crops for
fattening the spring farrowed pigs during the past year. The experi-
mental grazing plots consist of 2-acre areas. The crops were planted
as follows: Lot 1, Spanish peanuts and corn, one acre each; Lot 2, Spanish
peanuts; Lot 3, corn; and Lot 6, Spanish peanuts and sweetpotatoes, one
acre each. Since chufas (Lots 4 and 5) have made very low yields on
the station farm during the past three years, this crop has been dropped
from the experiment.
"Feeder" shotes from four to six months of age and as uniform in
size and grade as possible to obtain were used in grazing the crops. The
number of shotes used on each area depended upon the crop yield.
Gains made by the shotes on the various crops during the 1934 grazing
season rank as follows: 1st, corn; 2nd, corn and Spanish peanuts; 3rd,
sweetpotatoes and Spanish peanuts; and 4th, Spanish peanuts.
Eight shotes were fed in a dry lot during the test period. They re-
ceived the following ration: shelled corn, 10 parts; fish meal, 1 part.
The shotes were marketed during the early part of September.

RELATION OF CONFORMATION AND ANATOMY OF THE DAIRY
COW TO HER MILK AND BUTTERFAT PRODUCTION
State Project No. 140 R. B. Becker, W. M. Neal and P. T. Dix Arnold
Seven records of measurements and life histories of dairy cows as they
were eliminated from the Experiment Station dairy herd, were submitted
to the United States Department of Agriculture, Bureau of Dairy Industry.
These make a total of 29 such records contributed to this cooperative
project by this Station.


I







Florida Agricultural Experiment Station


FATTENING FALL PIGS FOR SPRING MARKET
State Project No. 160 W. W. Henley
It is desirable from an economic standpoint to obtain two litters of
pigs per year from brood sows. Grazing crops for fattening fall farrowed
pigs are rather limited; however, previous work has shown that runner
peanuts and sweetpotatoes will remain in the ground in good condition
during the winter months and may be hogged off during these months.
These crops were used in fattening the fall farrowed pigs in 1934 and
were planted as follows: Lot 1, runner peanuts; Lot 2, sweetpotatoes;
and Lot 3, sweetpotatoes and runner peanuts.
The grazing period began on December 9, 1934, and continued for 74
days. The yield was good for the crops on all areas. Gains made by
the pigs on the various crops rank in the following order: runner peanuts;
sweetpotatoes and runner peanuts (one acre each); and sweetpotatoes.

A STUDY OF FEEDING VALUE OF CROTALARIAS
State Project No. 175 R. B. Becker, W. M. Neal, A. L. Shealy
and P. T. Dix Arnold
Study of crotalarias, conducted in cooperation with the Agronomy De-
partment and the Division of Forage Crops and Diseases of the Bureau
of Plant Industry, U. S. D. A., has been carried on for four years. During
this time, 11 species have been tested for palatability as green forage,
as artificially dried hays and as silages. The results of the palatability
trials, and also of studies of growth and response under grazing or cutting,
were used as a basis to select the most desirable species for further study.
For this purpose, Crotalaria intermedia was selected.
Comparative feeding trials of C. intermedia silage versus No. 1 Federal
grade alfalfa hay have been conducted during the past two winters. Data
on ensiling changes and on silo capacity for this product are being obtained
at the same time. Four laboratory silos were used during the past year
with C. intermedia ensiled at different stages of growth. Cattle prefer
silage made from this plant harvested in pre-bud, followed by early bud,
early bloom and full bloom stages. Yields at the pre-bud stage are too
light to make this an economical time to harvest the crop.
The cooperators studied the possibilities of making hay by different
methods, the finished product being used in relative palatability tests with
mules. Mules refuse the coarser stems, consuming about 68 percent of
the crop as dried by the different natural methods.
Forage used in these trials was grown and supplied by the cooperators,
Mr. G. E. Ritchey being in charge locally for the Division of Forage Crops
and Plant Diseases.
SWINE FIELD EXPERIMENT
State Project No. 179 W. W. Henley
This project has been inactive this year.

THE DETERMINATION OF DIGESTIBILITY COEFFICIENTS FOR
CROTALARIA HAY
State Project No. 188 W. M. Neal and R. B. Becker
Since the digestion trials with hay made from Crotalaria intermedia
did not give satisfactory results, it was deemed advisable to substitute
crotalaria silage for hay in further trials. The coefficients of digestibility
for the silage were determined and the results published in Bulletin 279.
Work on this project has been completed.







Annual Report, 1985 53

THE EFFECT OF FEEDING CROTALARIA SEED TO CHICKENS
AND OTHER BIRDS
State Project No. 192 M. W. Emmel
Poultry:-The gross and histo-pathology of 21 chickens force-fed Crota-
laria spectabilis seeds has been studied. A severe anemia was often found
in chronic cases of poisoning. This anemia was caused by a marked de-
crease in the number of erythrocytes and seemed to be associated with
the development of ascites. The total number of white blood cells was
also reduced in many instances, in one case being as low as 12,500. Anemic
birds showed an increase in the percentage of vacuolar lymphocytes while
other birds often showed an increase in monocytes and myelocytes. Diag-
nostic lesions are: petechiae of the serious membranes, visceral fat, coro-
nary fat and myocardium in acute cases; necrotic enteritis, particularly
of the duodenum; an extremely dark liver usually presenting a marbled
appearance with a few areas being light brown in color; and gray foci
on the surface of the liver. The outstanding microscopic lesions were:
cloudy swelling of the parenchymatous tissue, heart muscle and smooth
muscle of the viscera with more or less accompanying edema; extensive
passive congestion; and necrosis of splenic and hepatic cells.
Studies on this project will be discontinued with this report, since all
work pertaining to poisonous plants for livestock and poultry will be con-
ducted under Purnell Project No. 258.

A STUDY OF THE ENSILABILITY OF FLORIDA FORAGE CROPS
State Project No. 213 W. M. Neal, R. B. Becker and P. T. Dix Arnold
Four laboratory silos were filled during the past year with Crotalaria
intermedia harvested at the pre-bud, early bud, early bloom, and full bloom
stages of maturity. A good quality of silage resulted in all cases. Muslin
bags containing 10-kilogram samples of the freshly-cut forage were buried
in the ensiled forage, and corresponding fresh samples taken to be used
in making determinations regarding the changes that take place in the
forage due to the ensiling process. The samples await analysis.
Ten sample bags were placed in each of three trench silos, filled with
Napier grass, Texas seeded ribbon cane (sorghum) and Cayana 10 sugar-
cane. Corresponding fresh samples were collected to be used in measuring
the changes that occur in the forage due to the ensiling process. Dry
matter losses of 10 percent, 15 percent and 22 percent, respectively, were
observed with these three crops. Green forage was weighed into the silos
at the time of cutting and all silage weighed out during the steer feeding
trial (State Project 241). Surface spoilage was reduced to a minimum
by the use of two-ply roofing paper under the dirt cover. Sugarcane made
the most acid silage and Napier grass the least acid as measured with
a glass electrode on pressed juice.
In a similar manner, five sample bags were used in a 20-foot silo filled
with C. intermedia (State Project 175). Dry matter content of this silage
was low, due to intermittent rains at the time of filling the silo. The
silage in the sample bags lost approximately 15 percent dry matter.
BEEF CATTLE BREEDING INVESTIGATIONS
State Project No. 215 A. L. Shealy
Results obtained during the past two years have shown clearly the
importance of breeding purebred bulls to native cows in grading up the
herds in this state. All cows used thus far in this project have been native
cows; however, first-cross heifers have been added to the herds during
the past year and offspring carrying 75 percent purebred blood will be







54 Florida Agricultural Experiment Station

obtained next spring. Many of these grade heifers, slightly over two years
of age, weigh practically as much as the average mature native cow within
the herds. There are four experimental herds of 40 native cows each and
a few first-cross heifers of all the breeds on which studies are being made
except the Red Polled. These four herds are headed by purebred bulls as
follows: Lot 1, Hereford; Lot 2, Devon; Lot 3, Brahman; and Lot 4, Red
Polled. In the first-cross offspring decided improvement is observed; the
individuals are thicker fleshed and have pronounced beef conformation.
The cows in all lots have been graded and a few first-cross heifers will
be graded as breeding cows within the near future. By grading native
cows and their grade offspring on identical scorecards, it is possible to note
improvement, if any, and the extent of improvement as a result of using
purebred bulls.
All calves are graded when three to four months of age as slaughter
calves. The heifer calves are retained for future breeding studies while
the bull calves are sold as slaughter calves. Records are kept on the price
received for the calves each year.
Work on this project is conducted at Penney Farms in cooperation with
Foremost Properties, Incorporated, and the United States Department of
Agriculture.

COOPERATIVE FIELD STUDIES WITH BEEF AND
DUAL-PURPOSE CATTLE
State Project No. 216 A. L. Shealy
It was deemed important to make studies in raising beef cattle in
various counties, since there are many types of ranges found in this state.
Work on this project is conducted on 24 farms and ranges, including areas
from Jackson County in the western part of the state to Lee County in
the south.
Purebred bulls of the Devon, Red Polled, Shorthorn and Angus breeds
have been loaned to cattle owners who breed them to native or grade
cows. Approximately 40 cows are bred annually to each bull used in this
project. Several first-cross calves have been obtained. Many of the grade
heifers will be of breeding age next year. The cows in the breeding herds
have been graded according to a system developed for grading native
breeding cows, and as the heifers are bred they will be graded on identical
scorecards as were the cows. Bull calves are sold as slaughter calves or
castrated and kept as steers on the ranges to be slaughtered when one
or two years old. All grade heifers are kept for future breeding studies.
Records are kept on percent of calf crop on each range; sex, age and
grade of offspring; type of range; number of acres allowed per animal;
and other important points regarding herd management.
Many of the bulls placed on loan agreement are owned by the Bureau
of Animal Industry, U. S. D. A., and all of these studies are in cooperation
with that organization.

DUAL-PURPOSE CATTLE INVESTIGATIONS UNDER
FARM CONDITIONS
State Project No. 217 A. L. Shealy
No work was conducted on this project.

FACTORS AFFECTING THE PERCENTAGE OF CALF CROP AND
SIZE OF CALVES
State Project No. 218 A. L. Shealy
No work was conducted on this project.







Annual Report, 1935 55

BEEF AND DUAL-PURPOSE CATTLE INVESTIGATIONS
State Project No. 219 A. L. Shealy
Herds of beef and dual-purpose cattle are maintained at the Main
Station, Gainesville; North Florida Experiment Station, Quincy; West
Central Florida Experiment Station, Brooksville; and the Everglades Ex-
periment Station, Belle Glade. Breeds used are as follows: Herefords
at Gainesville, Angus at Quincy, Red Polled at Brooksville, and Devons
at Belle Glade. The herds of Herefords at Gainesville and Angus at Quincy
consist of only a few animals. Herds of native cattle are maintained at
all of the above-mentioned stations. The native cows are bred to pure-
bred bulls to obtain grade offspring. Studies are made on native cows,
grade offspring, and purebred animals at all stations. Such a breeding
program makes it possible to obtain important data regarding the use
of purebred bulls in grading up the herds, and furnish grade offspring
of known breeding for feeding trials.
All native cows and their offspring are graded on a scorecard devised
for grading native cattle. All calves are graded as slaughter calves when
three to five months old. The heifer calves are retained for breeding
purposes while the bull calves are castrated and used in feeding trials.
Milk production records are obtained on purebred cows of dual-purpose
breeds at the Everglades Station and the West Central Florida Experiment
Station.
Work on this project is conducted cooperatively with the Bureau of
Animal Industry, United States Department of Agriculture.
INVESTIGATIONS OF HEMORRHAGIC SEPTICEMIA IN
CATTLE AND SWINE
Purnell Project No. 236 D. A. Sanders
Attempts to produce clinical cases of hemorrhagic septicemia were
undertaken by exposing cattle to organisms which were isolated from a
bull that died suddenly in a herd of cattle showing clinical symptoms of
the disease. Cultural and morphologic studies showed that these organisms
belonged to the pasteurella group and they were identified as Pasteurella
bovisepticus. Various routes of infection were tried on a limited number
of healthy calves and yearlings. These included wound inoculation, intra-
dermal, intraperitoneal, intravenous and subcutaneous injections of one
to two cubic centimeters of a suspension of the organism. Other methods
of exposure of experimental animals consisted of feeding agar and bouillon
cultures of P. bovisepticus; feeding the internal organs of laboratory ani-
mals which died from intraperitoneal injections or nasal insufflations of
organisms; by spraying the nasal passages; conjunctival and auricular
cavities with emulsions of the organisms; and by introducing them into
the sinuses of the head by means of a trephine.
Transient symptoms of the disease were produced in a small percentage
of the cattle exposed by heavy nasal spray of organisms that were highly
pathogenic for rabbits. P. bovisepticus organisms may exist in the upper
respiratory passages of cattle without producing disease.
Attempts to lower the resistance of cattle exposed to pasteurella were
undertaken by feeding virulent paratyphoid organisms and various stock-
poisoning plants, by introducing sand into the alimentary canal and by
producing anaphylactic shock. These factors failed to create conditions
necessary to bring about an invasion of the blood stream with pasteurella.
The Florida crow was found to be susceptible to infection with pas-
teurella organisms that were isolated from the upper respiratory tract
of cattle. The organisms were placed in the nasal cleft of several crows
and in their drinking water. Many crows thus exposed died from an acute







Florida Agricultural Experiment Station


septicemia and in these cases pasteurella organisms were readily demon-
strated and recovered from the blood stream and internal organs. Other
crows thus exposed withstood the infection for a greater length of time
and died after a period of three to four weeks. In these cases pasteurella
organisms were recovered from the liver, kidneys, and intestinal canal.
THE DIGESTIBILITY COEFFICIENTS AND FEEDING VALUE OF
DRIED GRAPEFRUIT REFUSE
(Amended to include dried orange cannery refuse)
Purnell Project No. 239 W. M. Neal, R. B. Becker and P. T. Dix Arnold
Fresh cannery refuse contains 80 to 85 percent moisture. When this
is reduced to about 10 percent moisture without too high temperature, a
very palatable by-product has been obtained commercially in Florida, for
use in feeding dairy cows.
Digestion trials with four steers have shown this by-product to rank
as a concentrate in feeding value, low in protein, fiber and fat but high
in digestible carbohydrates. Grapefruit refuse containing 8.3 percent
moisture yielded 1.23 percent digestible crude protein and 75.99 percent
total digestible nutrients. Dried orange refuse with 13.9 percent moisture
yielded 2.14 percent digestible crude protein and 69.55 percent total di-
gestible nutrients.
The fresh product has been fed to dairy cows in the vicinity of certain
canneries and in the Station herd without affecting the flavor of the milk.
The product appears not to be adapted for use with chickens and pigs.
It resembles beet pulp in many respects.
Two publications have appeared, Press Bulletin 466 and Bulletin 275.
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 No. 241 A. L. Shealy, W. M. Neal and R. B. Becker
Napier grass, Texas seeded ribbon cane (sorghum) and Cayana 10
sugarcane, respectively, were weighed into three trench silos in the autumn
of 1934. During the process of filling, 10 muslin bags containing 10 kilo-
grams net of the cut forage were distributed through the silage in each
silo for studies of changes that occur during the ensiling process. A layer
of two-ply roofing paper was placed over the cut forage and from 12 to
24 inches of soil placed over all.
The sound silage and any spoiled silage were weighed as removed from
the silo. These weights and data obtained from the chemical analyses of
silage in the bags and in samples collected during the feeding trial with
steers will be used in calculations of the efficiency of preservation of these
forages.
The silage was utilized as feed for long yearling steers and calves in
a feeding trial which began December 6, 1934, and continued for 130 days.
Thirty-six steers were divided according to weight and grade into three
uniform lots of 12 each. They were grade Angus, Shorthorn and Here-
ford. The steers were fed roughage as follows: Lot 1, Napier grass silage;
Lot 2, sorghum silage; and Lot 3, sugarcane silage. A uniform grain
mixture was given all lots.
During this trial, sorghum silage seemed to give best results, but silage
of both Napier grass and sugarcane were shown to be practical feeds.
The steers were graded as "feeder" steers at the beginning of the feed-
ing period and as slaughter steers at the close, when they were slaughtered.







Annual Report, 1935


A COMPARATIVE STUDY OF CORN AND LIQUID MILK VERSUS A
GRAIN AND MASH RATION IN FEEDING FOR
EGG PRODUCTION
State Project No. 244 N. R. Mehrhof and E. F. Stanton
Work on this project began October 15, 1933, and continued for 360
days. Two pens of Single Comb White Leghorns of uniform age and
breeding and reared under the same conditions were placed in two separate
houses of similar design. There were 40 pullets in each pen. All man-
agement practices were the same for both lots. The feed for Lot 1 con-
sisted of whole white corn and liquid milk while the birds in Lot 2 received
a grain and mash ration.
The results of the first year's work are given.
Average egg production per bird for the 360-day period: Lot 1, 166.54
eggs; Lot 2, 203.96 eggs.
Feed required to produce one dozen eggs: Lot 1, 4.83 pounds; Lot 2,
4.89 pounds.
Average amount feed consumed per bird: Lot 1, 67.03 pounds; Lot 2,
82.89 pounds.
Nine birds died in Lot 1, and three in Lot 2 during the course of the
experiment.
This experiment will be repeated for two more years.

A COMPARATIVE STUDY OF THE VALUE OF MEAT SCRAPS, FISH
MEAL, AND MILK SOLIDS AS SOURCES OF PROTEIN
FOR EGG PRODUCTION
State Project No. 245 N. R. Mehrhof and E. F. Stanton
A feeding experiment to compare the value of different sources of
protein for egg production commenced October 15, 1933, and continued
over a 360-day period. Four lots of Single Comb White Leghorn pullets
of uniform age and breeding and reared under the same management
practices were placed in four separate houses of similar design. Forty
pullets were placed in each lot.
During the course of the experiment the management for all lots was
the same. The basal ration was the same for all lots. This ration consisted
of bran, shorts, yellow corn meal, ground oats, alfalfa leaf meal, oyster
shells and salt.
Supplemental feed was added to the basal ration as follows: Lot 1,
meat scraps; Lot 2, meat scraps plus dried buttermilk; Lot 3, fish meal;
and Lot 4, fish meal plus dried buttermilk.
Egg production per bird for the 360-day period was as follows: Lot 1,
203.96 eggs; Lot 2, 218.46 eggs; Lot 3, 209.62 eggs; and Lot 4, 208.01 eggs.
Average amount of feed consumed per bird: Lot 1, 82.89 pounds; Lot 2,
83.96 pounds; Lot 3, 79.79 pounds; and Lot 4, 82.14 pounds.
Amount feed required to produce one dozen eggs: Lot 1, 4.88 pounds;
Lot 2, 4.61 pounds; Lot 3, 4.57 pounds; and Lot 4, 4.74 pounds.
During the progress of the experiment, the mortality in the lots was
as follows: Lot 1, 3 birds; Lot 2, 5 birds; Lot 3, 9 birds; and Lot 4, 12 birds.
This experiment will be conducted for two more periods.

LIGHTS VERSUS NO LIGHTS FOR EGG PRODUCTION
State Project No. 246 N. R. Mehrhof and E. F. Stanton
Studies on this experiment began October 15, 1933, and extended over
a 360-day period. Two lots of Single Comb White Leghorn pullets of
uniform age and breeding and reared under the same conditions were placed








Florida Agricultural Experiment Station


in two separate houses of similar design. There were 40 pullets in each
lot. The feed used for both pens was the same. All management practices
were the same with the exception of light. The birds in Lot 1 received
artificial illumination in the early morning hours while Lot 2 birds received
no light.
The egg production per bird for the 360-day period was as follows:
Lot 1, 206.62 eggs; and Lot 2, 203.96 eggs.
The egg production per bird for the first 150 days, during the season
of high prices: Lot 1, 89.33 eggs; and Lot 2, 77.46 eggs.
Average amount feed consumed per bird for period: Lot 1, 80.76
pounds; and Lot 2, 82.89 pounds.
Amount feed required to produce one dozen eggs: Lot 1, 4.69 pounds;
Lot 2, 4.88 pounds.
Seven birds died in Lot 1 while three died in Lot 2 during the course
of the experiment.
This experiment will be conducted for two more periods.

EFFECT OF FEEDING COLON ORGANISMS AND DRIED WHEY ON
THE BACTERIAL FLORA OF BABY CHICKS AFFECTED
WITH PULLORUM DISEASE
State Project No. 250 M. W. Emmel
A ration consisting of 15 percent dried whey, as the only milk product
in the feed, is effective in reducing losses in outbreaks of pullorum disease
under experimental conditions. Under field conditions the treatment has
met with favor by all who have used it. It is not advisable, however, to
make a practice of feeding a ration consisting of 15 percent dried whey
to chicks continuously for the first three weeks of life as a preventive
against pullorum disease. Experiments show that under such feeding
practices many chicks develop a diarrhea at seven to 10 days of age and
if exposed to Salmonella pullorum many die of pullorum disease.
Fifteen percent dried whey should be looked upon as a feed useful in
lowering the mortality in chicks in outbreaks of pullorum disease but
should not be considered beneficial in preventing the disease.
The results obtained by adding 15 percent dried whey to the ration
as a means of treating the disease depends upon how soon this ration Is
fed after infection has occurred. In experimental birds the sooner such
a ration was fed after infection the less were the losses from pullorum
disease.

THE ETIOLOGY OF LEUKEMIA IN THE DOMESTIC FOWL
State Project No. 251 M. W. Emmel
Repeated intravenous injections of Salmonella aertrycke in birds over
12 weeks of age induced cases of erythroleucosis and myeloid leucosis.
Erythroleucosis apparently represents a more severe infection than myeloid
leucosis. The incubation period was from 27 to 253 days, during which
time hemocytoblastosis is present as shown by blood examinations. Lym-
phocytoma apparently is caused by a lighter infection than myeloid leucosis;
tissue vulnerability may be an important factor. Erythroleucosis, both
lymphatic and erythroblastic, and myeloid leucosis induced by S. aertrycke
are transmissible to healthy birds by means of the injection of tissue
emulsions of affected organs.
Considerable progress is being made in efforts to induce leukemia in
larger animals by means of intravenous injections of micro-organisms
of the paratyphoid and typhoid groups.







Annual Report, 1935


A STUDY OF PLANTS POISONOUS TO LIVESTOCK IN FLORIDA
Purnell Project No. 258 D. A. Sanders, M. W. Emmel and Erdman West
Cassia occidentalis was found to be poisonous for cattle, producing
death in many cases. Observations showed that cattle would eat the mature
seedpods of this plant when grazing was scarce. Small amounts of the
immature plants produced severe diarrhea in experimental animals.
A chronic form of crotalaria poisoning was found in a large herd
of beef cattle. These cattle had grazed for a period of two weeks in a
field containing a heavy growth of C. spectabilis. It was observed that
cattle ate the seedpods of this plant. However, it appears that they will
eat the pods or any part of the plant only when other feed material is
scarce.
Experimental feeding of sheep with ground seed of C. spectabilis pro-
duced symptoms of poisoning. If the administration of the seed was with-
held when the first symptoms were manifested, the animal would recover.
When the administration of the seed continued, death resulted in from
40 to 76 days.
Ground seed of C. spectabilis force-fed to hogs in two gram daily doses
and in one-half gram daily doses proved toxic. Whole seed administered
in capsules passed undigested through the alimentary tract of experimental
animals.
Subsequent investigations have shown that swine are more apt to be
poisoned under natural conditions from the green forage of C. spectabilis
than by the seed of this plant. It has been observed that swine will eat
the green plant when other green grazing crops are scarce in the field.
Field cases of cockle-bur poisoning were observed in a herd of swine.
The herd consisted originally of 46 animals, and 16 died as a result of cockle-
bur poisoning. The symptoms and post-mortem lesions of cockle-bur
poisoning were studied.
A feeding trial with tung seed meal showed that this material is un-
palatable and poisonous for swine. Pigs fed a ration containing 10 percent
of tung seed meal did not die of acute poisoning. However, when these
pigs were slaughtered marked pathological changes were observed in the
heart, lungs, spleen and kidney.
Glottidium vesicarium (Jacq.) Harper was found to be poisonous to
chickens; 150 seed force-fed in a single dose proved fatal for adult S. C.
White Leghorns. Well-fed birds refused to eat the seed voluntarily under
experimental conditions; semi-starved birds ate some seed but not enough
to prove fatal. The lesions of G. vesicarium poisoning have been studied
in experimental birds. Two natural cases of poisoning in chickens have
been observed. The lesions found in these cases were typical of those
found in the experimental cases of poisoning.







Florida Agricultural Experiment Station


CHEMISTRY AND SOILS
The work of the department was along the same general lines as in the
previous year. In addition to the work on the various projects, about 300
soil acidity determinations were made for various individuals and county
agents.
A paper, "The Effect of Fertilizers and Soil Types on the Mineral
Composition of Vegetables" by J. M. Coleman and R. W. Ruprecht, was
published in the Journal of Nutrition, Vol. 9, No. 1, and seven articles
of a semi-technical nature were published in agricultural journals. A paper
entitled "The Living Soil" was presented by R. M. Barnette before the
Grape Growers Convention at Leesburg, and a paper entitled "The Effect
of Acid and Non-Acid Fertilizers on Norfolk Fine Sand" by R. W. Ruprecht
and C. E. Bell, was presented before the Florida Horticultural Society.
Radio talks on timely topics were given on an average of once a month
over Station WRUF by members of the department.
The extreme cold of December 12 and 13, 1935, seriously affected work
dealing with citrus. Many trees were severely killed back and much of
the fruit still on the trees was badly frozen. However, individual tree
yield records were kept of the dropped frozen fruit as well as that remaining
on the trees.
DIEBACK OR EXANTHEMA OF CITRUS
State Project No. 21 B. R. Fudge
Refer to report of the Citrus Station.

DETERMINATION OF THE EFFECT OF VARYING AMOUNTS OF
POTASH ON COMPOSITION, YIELD AND QUALITY OF THE CROP
Hatch Project No. 22 R. W. Ruprecht
In the amount of potash tests the plots receiving only 3% potash three
times a year again produced the largest crop of grapefruit. In the case
of the oranges no outstanding differences in yield were noted. Some
preliminary tests on leaves and shoots from these plots showed a higher
ammonia and phosphorus content in the juice from the 3% potash trees,
while the juice from the 10% potash plots had a higher potassium content.

DETERMINATION OF THE EFFECT OF VARIOUS POTASH
CARRIERS ON GROWTH, YIELD AND
COMPOSITION OF CROPS
Hatch Project No. 37 R. W. Ruprecht
In the source of potash tests the results were somewhat contrary. In
the case of tangerines, largest yields were obtained from the plot receiving
all its potash as the muriate. With oranges, highest yield was obtained
from the plot receiving all potash as the high grade sulfate, while with
grapefruit highest yield was obtained on the plot receiving all potash
from the low grade sulfate of potash magnesia.
Only samples of oranges picked before the freeze were analyzed. The
tangerines and grapefruit were severely injured by the cold. No differences
in composition of the oranges were found.

COMPOSITION OF CROPS AS INFLUENCED BY FERTILIZATION
AND SOIL TYPES-PECANS
State Project No. 67 H. W. Winsor
All chemical work on this project has been discontinued. Only one
experiment, in cooperation with the U. S. Department of Agriculture, located








Annual Report, 1985 61

near Jacksonville is being continued. A very light yield was obtained
from these plots.
In cooperation with the Horticulture Department, Bulletin 270, "Fer-
tilizer Experiments with Pecans," was published.
EFFECT OF VARIOUS FERTILIZER FORMULAS
State Project No. 94 R. W. Ruprecht
Citrus: In the source of nitrogen tests with citrus the sulfate of am-
monia plot produced the highest yield when superphosphate was the source
of phosphoric acid, but nitrate of soda produced the highest yield when
the phosphoric acid was derived from steamed bone meal. The best quality
of fruit was produced on the plots receiving ammonia from dried blood
with second on the plots receiving sulfate of ammonia. In all cases the
fruit and the condition of the trees was better on the plots receiving
steamed bone meal. Soil studies to determine the cause of the difference
in quality and yield of the different plots have not as yet been successful.
Analysis of the juice extracted from leaves from the various plots showed
that sodium nitrate produced leaves with the greatest amount of nitrogen.
Apparently there is a correlation between the nitrogen content of the
leaves and stems and the quality of the fruit produced. The best quality
of fruit was produced on the trees with the lowest nitrogen content in the
leaves. Analyses showed a consistently higher sucrose content in the
fruit from the bone plots.
Potatoes: Only a small crop of potatoes was harvested from the ex-
perimental plots at Hastings due to cold injury of the plants. In the
nitrogen tests calnitro produced the highest yield, but the differences be-
tween the plots was small. The addition of secondary plant foods, mag-
nesium, copper, zinc or manganese, had no influence on yield. Reducing
the phosphoric acid content in the fertilizer to 2% had no effect on yield.
It is possible that the plants received some residual benefits from fertilizers
used previously which contained 7% phosphoric acid, although these plots
have received only 2% phosphoric acid for the past three years.
CONCENTRATED FERTILIZER STUDIES
State Project No. 95 R. W. Ruprecht
In the concentrated fertilizer experiment with citrus at Lake Alfred,
conducted in cooperation with the U. S. D. A., the highest yield was
obtained on the plot receiving normal strength fertilizer. Of the con-
centrated mixtures, fertilizer A made from ammophos, ammonium nitrate
and sulfate of potash again had the highest yield.
All trees were injured by the freeze in December and the dry weather
this spring.
At Lake Harris the difference noted last year in the urea and sulfate
of ammonia plots has disappeared. Trees in all plots made a good growth,
had a fair yield and have set a good crop of fruit. This grove suffered
practically no injury from the December cold. No difference in yield due
to the fertilizer used was apparent.
In these plots the citrus trees apparently have grown just as satisfac-
torily with all phosphoric acid and potash applied only once a year as
where applied in three applications.
DETERMINATION OF THE EFFECT OF GREEN MANURES ON THE
COMPOSITION OF THE SOIL
Adams Project No. 96 R. M. Barnette
Field Cover Crop Experiments: The analyses and vegetative green-
house tests with volume soil samples removed from plots in a pecan grove







Florida Agricultural Experiment Station


subjected to different combinations of summer and winter cover crops
have been completed. Non-leguminous plants made a better growth and
recovered more nitrogen from the soil which had been cover-cropped to
Crotalaria spectabilis in the summer and vetch or Austrian peas in the
winter than from the soil which had not been cover cropped. The nitrogen
content of the soil from the plots which had both summer and winter
cover crops was higher than that of the plot which had no cover crops.
The results of these soil analyses and vegetative tests have been compiled
in cooperation with the Horticultural Department. In this report the tree
growth, nut yields, cover cropping systems and soil changes have been
correlated.
Experiments are being conducted on the application of the so-called
secondary plant nutrients to the soil in an attempt to improve the growth
of Crotalaria spectabilis and striata on the sandy soils of the citrus section.
To date none of the less abundant elements have materially improved the
growth of these plants on the sandy ridge soils.
Soil Moisture Studies in Relationship to Cover Crops: The moisture
content of different depths of soil planted to summer and winter cover
crops is being compared with that of an adjacent plot of the same soil
kept free from vegetation. The soils planted to cover crops have been
lower in moisture content than bare soil, especially in the lower soil depths.
The experiment has been conducted in cooperation with G. H. Blackmon,
who has kept temperature records of the differently treated soils.
Phytometer Studies on the Comparative Rate of Decomposition of
Crotalaria striata, spectabilis and intermedia: In a comparison of the
relative rates of decomposition of the three most common species of
Crotalaria used in the state as cover crops, Crotalaria striata and inter-
media were found to decompose less rapidly than Crotalaria spectabilis
as measured by the residues left in the soil after a definite period of
decomposition.

A STUDY OF CHLOROSISS" IN CORN PLANTS AND OTHER
FIELD CROP PLANTS
Adams Project No. 220 R. M. Barnette
Experiments on the use of zinc sulfate, manures, leaf mold and "land
resting" for the correction of white bud in corn were completed and the
results written up in bulletin form. The experiments showed that 12 to
20 pounds per acre of zinc sulfate definitely stimulated the growth and
yield of corn and overcame the white bud condition. Leaf mold and
manures as well as land resting reduced or completely overcame the white
bud condition. On analysis it was found that both the leaf mold and
manures contained some zinc. Analysis of weeds growing on rested plots
showed that they contained from 2 to 50 times as much zinc as a planted
crop of crotalaria.

BRONZING OR COPPER LEAF OF CITRUS
State Project No. 223 C. E. Bell and R. W. Ruprecht
In the experiment on the effect of lime or soil reaction on bronzing
of citrus, large additions of limestone have only had a slight influence on
the pH of the soil. Some of the trees have now had 72 pounds of ground
limestone applied during the past two years, yet the change in the pH
has been slight. No effect on tree growth or yield and quality of fruit
has been found.








Annual Report, 1935


THE OCCURRENCE AND BEHAVIOR OF LESS ABUNDANT
ELEMENTS IN SOILS
Adams Project No. 240 H. W. Jones
In studies with less common elements, most work has been done with
zinc. It has been found that a large part of the zinc when added to the
soil is held in the soil in replaceable form, replacing calcium principally.
On marl and alkaline organic soils considerable quantities of zinc are held
as the humate and carbonate. In Norfolk fine sand the presence of 200
ppm. of zinc in replaceable form decreased plant growth, while 300 ppm.
were definitely toxic. Calcium carbonate applied to the soil at the rate
of 1,000 pounds per acre alleviated the toxic condition.
SOIL AND FERTILIZER STUDIES WITH CELERY
State Project No. 252 E. R. Purvis and R. W. Ruprecht
The most outstanding result of the celery investigations was the effect
of small applications of borax in overcoming "cracked stem," one of the
most serious diseases occurring in the Sanford area. Applications of 10
pounds of borax to the acre completely prevented the occurrence of cracked
stem and also increased the growth and subsequent yield of celery. Ap-
plications of as much as 30 pounds of borax per acre were definitely toxic.
Preliminary studies on the optimum soil reaction for celery seedbeds indi-
cate that a pH between 6.0 and 6.5 is best. Preliminary studies on the
chlorine content of well waters in the Sanford area indicate no toxic
quantities of salt in any of the wells so far tested.
All of the fertilizer tests were unsatisfactory, due to adverse weather
conditions and the appearance of cracked stem on all plots except those
treated with borax. Tests with a large number of the so-called rare
elements showed that the celery plants respond to manganese in the absence
of iron and to zinc. Cobalt proved decidedly toxic.







Florida Agricultural Experiment Station


ENTOMOLOGY
Research activities of the department were conducted under 15 projects,
14 of which concerned insect pests of plants and one vertebrate pests of
watermelons. The project on the asparagus caterpillar has been com-
pleted and the findings published as Bulletin 271.
Outstanding entomological feature of the year was the discovery in
Manatee County of the pepper weevil, Anthonomus eugenii Cano. This
insect, whose larvae feed on the buds of peppers and on the fruits in all
stages of development, gives promise of becoming a serious pest of peppers
in Florida. C. C. Goff is being transferred from the Leesburg Laboratory
to Bradenton where he will study the biology of the insect and strive
for practical and economical means of control.
In addition to work done under the regularly conducted projects, mem-
bers of the department have rendered much service to the agricultural
interests of the state, directly through correspondence and personal contact
with farmers and indirectly through the extension agencies, by giving
advice concerning insect problems and suggesting methods of control of
economic pests.
A very large number of insect specimens have been identified for indi-
viduals and for other institutions. Special mention may be made of the
identification of all thysanoptera taken by the Bureau of Entomology and
Plant Quarantine, U. S. D. A., and by the Florida State Plant Board
inspectors, as well as collections of some other experiment stations.

THE FLORIDA FLOWER THRIPS
(Frankliniella cephalica bispinosa Morgan)
State Project No. 8 J. R. Watson
Florida flower thrips became very abundant in late April and May,
following the period of sub-normal rainfall since October 1934. In the
northern part of Marion and the southern part of Alachua counties beans
were severely attacked. The infestation started on garden peas during
late winter and when these were plowed under the thrips migrated to the
beans. The beans were not blooming at that time and the thrips fed on
the leaves, causing a distinct curling and yellowing. When the bean
blossoms appeared the thrips moved to these in large numbers, the females
appearing first. Thrips in the blossoms caused an abnormal dropping
of bloom. The heavy infestation of flower thrips came too late in the
season to damage citrus bloom. No further experiments were tried for
the control of thrips on citrus.
The survey of the thysanoptera of Florida was continued. The Cuban
flower thrips (Frankliniella cubensis Hood) and an undescribed species
of flower thrips which were taken at Key West by J. W. Kea, constituted
additions to the known thysanoptera of the state. The Cuban laurel thrips
(Gynaikothrips uzeli), which occurs in the southern part of the state,
apparently spread over wider territory during the year. It was sent in
from St. Petersburg, which is farther north than any point from which
it previously has been taken.

ROOT-KNOT INVESTIGATIONS
Adams Project No. 12 J. R. Watson
Further work was done on the method of starving out root-knot nema-
todes by the use of Crotalaria spectabilis. The recommended procedure
has been to plant the crotalaria in rows and cultivate it frequently to
eliminate other plants and to aerate the soil. The question arose as to







Annual Report, 1935 65

the necessity of soil aeration by cultivation, since crotalaria leaves falling
to the ground form a mulch which seems to prevent the formation of a
crust on the soil surface. It was found that, with a pure stand of crotalaria,
control was fully as good where it was sown broadcast without cultivation.
However, where other plants were allowed to grow with the crotalaria,
control was much less complete. Evidently aeration of the soil by culti-
vation is not essential to the starvation of the nematodes but cultivation
ordinarily is necessary to eliminate the other plants that may serve as
hosts of the nematodes.
C. C. Goff completed his investigations of the susceptibility of the
annual ornamental plants to root-knot before departing on his leave of
absence in October. His findings have been recorded'in manuscript form.
This work with ornamentals has been continued at Gainesville by H. E.
Bratley, who used some of the plants tested by Mr. Goff, but at different
seasons of the year. He also grew a number of ornamentals that were
not planted at Leesburg.

INTRODUCTION AND PROPAGATION OF BENEFICIAL INSECTS
State Project No. 13 J. R. Watson and W. L. Thompson
Observations were continued on the Chinese ladybeetle (Leis dimidiata
var. 15-spilota Hope). It was feared that the freeze of December and the
dry weather preceding and following it, resulting in a scarcity of new
growth on citrus and consequently a dearth of aphids, would have a very
serious effect on the colony of these beetles which has become established
in the northern part of Orange County. However, with the coming of
new growth and aphids in the spring, the beetles reappeared, although
perhaps not in as great numbers as in other years. They have continued
to spread slowly and are now found over an area with a radius of seven or
eight miles, being found as far east as Orlando and as far north as Apopka,
as well as around the original location at Sand Lake. Efforts to colonize
the beetles in other parts of the state were made but without apparent
success.
The factor that apparently limits their ability to become established
in any region seems to be that of summer food. They were found feeding
in the summer of 1934 and the spring of 1935 on the pollen of fire weed
(Erechtites sp.), Crotalaria striata, blossoms of the saw palmetto, and
the gum exuding from wounds in citrus trees. These foods simply serve
to carry the beetles through the summer when aphids are scarce and no
reproduction of the beetles takes place at this time.
As in previous years no parasites, either insects or entomogenous fungi,
were observed on this ladybeetle. It is undoubtedly this immunity from
parasites which enables this beetle to become so much more abundant in
citrus groves than do the native ladybeetles. Observations in the groves
where this beetle is found further emphasized its value to citrus growers
and attempts will be continued to colonize it in other parts of the state.
It is very evident that the most propitious time to introduce the beetles
into groves is in early spring at the beginning of the aphid season, but it
is difficult at that time to obtain the beetles in sufficiently large numbers.

THE LARGER PLANT BUGS
State Project No. 14 H. E. Bratley
Leptoglossus phyllopus infested citrus, especially satsumas, in moderate
numbers during the fall of 1934. Their food supply was suddenly cut off
by the freeze of December 12, with the result that only about half the
usual number survived the winter. A much larger proportion than usual



3

___________________^_ ____







Florida Agricultural Experiment Station


of the survivors found on thistles in the spring bore eggs of parasitic flies,
counts indicating that from 25 to 50 percent of the bugs had eggs on
them.
Acanthocephalus femorata and A. confraterna, the latter less abundant,
did not seem to be as severely affected by the cold as L. phyllopus, though
like that species a larger percentage than usual bore parasite eggs.
Nezara viridula was abundant in the fall of 1934 and did not appear
to be seriously affected by the cold of December. In this species also
parasitization was much higher than usual, at one time 95 percent of
the bugs showing eggs of parasites.

BEAN JASSID INVESTIGATIONS
Adams Project No. 28 A. N. Tissot
This project has been relatively inactive during the year, activities
consisting mainly of making observations on distribution, relative abund-
ance, and biology of the insect, (Empoasca fabae (Harris)). Jassids
were abundant in the Everglades and on the lower East Coast during
the winter and did considerable damage to the early spring crop of beans
in those sections. In the central part of the state the heavy jassid infesta-
tion that usually develops on the fall crop of beans failed to materialize.
Due to the fact that there have been practically no jassids in this region
during the past year, it was found necessary to postpone some proposed
control experiments.

THE GREEN CITRUS APHID
Adams Project No. 60 J. R. Watson and W. L. Thompson
Due to the severe drought of winter and the freeze of December 12,
with the resultant scarcity of tender growth on citrus, the green citrus
aphid (Aphis spiraecola Patch) was very scarce during the spring of
1935. On account of this scarcity of aphids field scale control experiments
were not possible. Observations on the biology of this insect and the
results of laboratory spray tests are given under State Project No. 234.

CONTROL OF FRUIT AND NUT CROP INSECTS-INSECTS
AFFECTING PECAN TREES
State Project No. 82 J. R. Watson and G. B. Fairchild
Work on the pecan nut case-bearer (Acrobasis caryae) was continued.
The late F. W. Walker had tested on a small scale a dormant spray using
a tar distillate with very favorable results, and it was thought advisable
to test this material on a larger scale. A block of 49 trees in the
"Eldorado" orchard of Judge T. B. Bird was selected. The spray was
applied with a special pecan gun at a pressure of 400-500 pounds. The
spray was applied March 19 and 20. The temperature was above 80
degrees F. both days and there was no wind. The trees had just begun
to shed the outer bud scales. Preliminary counts indicate no significant
difference in amount of nut case-bearer injury on sprayed and unsprayed
trees. It seems probable that the spray was applied when the temperature
was too low or the tree buds had not sufficiently opened.
It seems very desirable to obtain more definite information concern-
ing the causes responsible for the shedding of pecan nuts. Six trees were
selected for this purpose and hexagonal platforms covered with galvanized
screening were set up beneath them. These platforms slope from the
periphery toward the center where an opening is left and a cloth bag
arranged for the reception of any nuts that fall from the tree and roll


L








Annual Report, 1935 67

down the platform. Beginning May 23, all drops were gathered weekly
and examined for case-bearer infestation or other causes of dropping.
A preliminary count shows a potential loss of from 25 to 40 pounds of
nuts per tree, calculated on the basis of 65 ripe nuts per pound. Of this
loss only about 10 percent is due to nut case-bearer.

CONTROL OF SCALE-INSECTS ON WOODY ORNAMENTALS
State Project No. 157 J. W. Wilson
No scale-insects were observed on woody ornamentals during the year
and it was therefore impossible to conduct control experiments.

INSECT AND OTHER ANIMAL PESTS OF WATERMELONS
State Project No. 162 C. C. Goff
Due to the absence of Mr. Goff on leave during most of the year, no
work was done on this project.

BIOLOGY AND CONTROL OF FIELD MICE IN WATERMELON
PLANTINGS
State Project No. 214 C. C. Goff
No additional information was gathered on this project.

THE ASPARAGUS CATERPILLAR (Laphygma exigua)
State Project No. 230 J. W. Wilson
This project was completed and closed with the publication of Bulletin
271, "The Asparagus Caterpillar: Its Life History and Control."

THE ONION THRIPS (Thrips tabaci Linden)
State Project No. 231 J. R. Watson
Heavy infestations of the onion thrips occurred in Sarasota County
and around Belle Glade in Palm Beach County. In Sarasota County
the damage was mostly to celery and was very severe. The thrips attacked
chiefly the buds or very tender young leaves of the celery. On very small
newly transplanted celery the thrips are mostly found at or below the
surface of the ground. As the celery grows larger the thrips are still
found on the more tender leaves but well above the ground surface.
At Belle Glade where little celery is grown, the damage by the onion
thrips was confined largely to beans, though the first infestation was
found on peas and onions. The damage to the beans was confined almost
entirely to the leaves.
Experiments were conducted for the control of this thrips on celery.
On very young, newly transplanted celery the best control was obtained
by spraying the plants with nicotine sulfate or some of the sprays con-
taining pyrethrum. High pressure was necessary to force the spray
down into the buds. The ordinary traction sprayer used for the applica-
tion of Bordeaux mixture did not give a sufficiently thorough coverage.
On older celery, particularly that which had been prepared for blanch-
ing, nicotine and rotenone dusts gave better control than did the liquid
sprays because it was so difficult to get sufficient penetration of the spray
through the covering of outer leaves. A considerable acreage of celery
in Sarasota County was dusted from an airplane, using a commercial
pyrethrum dust. This gave fairly satisfactory control of the thrips but
on the whole was not as effective as careful ground work, with a spray
on young plants or dust applied beneath the outer leaves of older celery.








Florida Agricultural Experiment Station


Naphthalene mixed with an equal weight of lime gave a very satis-
factory control of the thrips and caused no serious burning of the foliage.
Many growers were of the opinion that the naphthalene tainted the celery.
This, however, would not be objectionable if used on young celery long
before time of marketing. Naphthalene offers a promising means of
control not only on account of the kill obtained but the odor persists for
some days and should repel the thrips, offering longer protection to the
plants than nicotine or rotenone.
It was found that onions planted in a field at some distance from wild
vegetation were more likely to escape injury from the thrips than those
planted near grass and weeds. A study was made of other host plants
of this thrips and these were found to be numerous.

THE GLADIOLUS THRIPS (Taeniothrips gladioli M.&S.)
State Project No. 232 J. R. Watson and J. W. Wilson
The gladiolus thrips has continued to spread throughout the state.
It is now found in practically all sections, though by no means in all
plantings. In plantings where no bulbs have been obtained from outside
sources the thrips usually are absent unless other infested plantings are
situated nearby. Heretofore the thrips have not been found on bulbs
kept in storage throughout the summer. In the past year bulbs inspected
early in August were found to be lightly infested. Though the thrips
may occasionally go through the summer on bulbs in storage, undoubtedly
the chief manner of summer survival is on volunteer plants that spring
up in the fields after the bulbs are dug.
The life history of this insect has been studied throughout the year
at Leesburg. Eleven complete generations occurred from July 1, 1934,
to July 1, 1935. Development was most rapid in" the spring from April
to June and again in October and early November. Development was
somewhat retarded during summer and in winter a generation required
twice as long as in spring or fall.
Of all the insecticides tried against this thrips a commercial rotenone
dust gave the best results. Four percent nicotine sulfate-lime dust gave
a good control, as did pyrethrum dusts. It is important to begin the con-
trol measures early before the infestation gets too heavy. Once the whole
field becomes infested it is difficult to bring the insect under commercial
control.

CONTROL OF PURPLE SCALE AND WHITEFLIES WITH
LIME-SULFUR
State Project No. 233 W. L. Thompson
Refer to the report of the Citrus Experiment Station.

BIOLOGY AND CONTROL OF FLORIDA APHIDS
State Project No. 234 A. N. Tissot
Eighty-four collections of Florida aphids and 20 interceptions of aphids
by the port inspectors of the State Plant Board were recorded during the
past year. The Florida collections represent 40 species, of which two
have not been recorded from the State before this year. These two
species, Aphis rumicis L. and Myzus pseudosolani Theob., were taken from
Sonchus oleraceus L. and Hydrocotyle umbellata L., respectively. Twenty
species of plants were added to the list of known hosts of Florida aphids.
A week of cold weather in December, climaxed by a low temperature
of 16 degrees, afforded an excellent opportunity to observe the effect of
cold on aphids. For a few weeks following this cold period it was im-


L







Annual Report, 1935 69

possible to find any aphids but a few survived as they promptly reappeared
on the first new growth pushed out by plants. This early reappearance
indicates that low temperatures in Florida serve only to check aphids
temporarily.
Records were kept on the predators and parasites of Aphis spiraecola
Patch in the groves near the University Campus. With one exception
the predators and parasites found during the year were the same as those
found the preceding year. Syrphus wiedemannt was not taken last year.
This fly ordinarily appears during winter and as no aphids were found
at that time its absence is readily understood.
Some new contact insecticides were tested in small scale laboratory
experiments using Macrosiphum pisi and Aphis spiraecola. Parallel tests
were run using nicotine sulfate and other standard aphicides for com-
parison. None of the new materials tested proved very superior to
nicotine sulfate with a good spreader, though some of them appear to
be very effective aphicides.








Florida Agricultural Experiment Station


HOME ECONOMICS

Two closely correlated lines of investigation have constituted the prin-
cipal work of the Department of Home Economics. One is concerned
with diseases of nutritional origin, the other with the chemical composi-
tion of Florida fruits and vegetables as related to nutritional diseases.

RELATION OF GROWTH TO PHOSPHORUS, CALCIUM, AND LIPIN
METABOLISM AS INFLUENCED BY THE THYMUS
Purnell Project No. 142 C. F. Ahmann
Since it had been shown previously that a relationship exists between
the condition of the thymus and the state of nutrition of an animal, the
effects of extirpation of the gland on the metabolism of a rabbit has
been studied. Operative work has been continued and there are now 20
thymectomized rabbits in the colony. Mineral analyses were made of the
ash of muscle, bone, blood, brain, and organs of sexually mature thy-
mectomized rabbits of the first generation. The data show that the
calcium of the blood, the magnesium and phosphorus of the muscle of
thymectomized rabbits were higher than in the controls. No significant
changes were noted in the mineral content of the other organs and tissues.
Mineral analyses of the ash of tissues and organs of thymectomized rabbits
of the second generation are now in progress. There are indications that
the maximum effect of thymectomy is not evident until the second and
third generations.

A STUDY OF LECITHIN SYNTHESIS IN HENS ON A VITAMIN A
AND LIPOID FREE DIET
Purnell Project 198 0. D. Abbott
The effect of a diet low in vitamin A and lipoids on the nutrition of
hens is one phase of avitaminosis that has been investigated. On a diet
lacking these constituents the hens showed symptoms of malnutrition and
died in about four months. If to the diet of skimmed milk and rice starch,
yeast and carotin were added, the birds remained in good condition for
seven to eight months. If, however, in addition to the above diet, each
hen received 1 gram of lecithin daily they remained in good condition
and continued to lay for more than a year. Whether the improvement
was due to the lecithin or to the fat radical is now being investigated.

A STUDY OF THE HEMATOPOIETIC TISSUES OF RATS ON A DIET
LOW IN VITAMIN A
Purnell Project No. 199 O. D. Abbott
When rats were fed diets low in vitamin A for 8 to 12 months,
degenerative changes occurred in the blood cells, especially in the leucocytes.
Immature leucocytes appeared which indicated exhaustion of certain of
the hematopoietic tissues. It is of interest to note that all the experimental
animals died of pneumonia, and that only a few of them showed evidence
of xerophthalmia, the symptom most common in avitaminosis A.
In cooperation with the city health nurse and the Memphis City Hospital,
a study was made of the blood of paupers and individuals who had been
malnourished for a long time. In a number of cases where collapse had
occurred the blood picture was similar in every respect to that of the
rats. In the few cases on which data are available, it was observed that
a diet high in vitamin A brought about improvement.







Annual Report, 1935


A STUDY OF THE CHEMICAL COMPOSITION OF THE ASH OF
FLORIDA FRUITS AND VEGETABLES WITH REFERENCE
TO THE MORE UNUSUAL CONSTITUENTS
Purnell Project 201 L. W. Gaddum
Spectrographic analyses (qualitative with estimate) were made of
some citrus fruit and soil samples; this work was largely exploratory
and was preliminary to a study of the .mineral content of citrus tissues
and corresponding soils to be undertaken during the next fiscal year.
This preliminary work showed the consistent occurrence of barium, stron-
tium, chromium, aluminum, manganese, boron, copper and zinc in all
samples analyzed.
A spectrographic study of fertilizer materials as regards their content
of certain trace elements (barium, strontium, vanadium, chromium, man-
ganese, nickel, cobalt, silver, copper, cadmium, tin, titanium, bismuth,
antimony, boron and zinc) was carried out in cooperation with the Florida
Agricultural Research Institute. The results are to be submitted for
publication in bulletin form.

A STUDY OF THE CHEMICAL PROPERTIES OF THE GLUCOSIDES
OF CITRUS FRUITS
Purnell Project No. 221 L. W. Gaddum
In the attempt to obtain means of identification of the citrus glucosides
(other than by the phloroglucinol reaction) a study of the absorption
spectrum of naringin and related materials was initiated.
For light sources to be used in this work, a tungsten underwater spark
gap and a hydrogen discharge tube were built and tested.
To standardize the equipment, absorption spectra of benzene, toluene,
and a few other materials were made.
Absorption spectra of naringin, acetophenone, cinnamic acid and other
related materials were made. The spectra have not as yet been analyzed;
this work is in progress.

AN INVESTIGATION OF HUMAN DIETARY DEFICIENCIES IN
ALACHUA COUNTY, FLORIDA, WITH SPECIAL REFERENCE
TO NUTRITIONAL ANEMIA IN RELATION TO THE
COMPOSITION OF HOME-GROWN FOODS
Purnell Project No. 255 0. D. Abbott
Probably the most important phase of the work on diseases of nutri-
tional origin has been the study of anemia of rural school children. Hemo-
globin determinations of approximately 5,000 school children living in
different sections of the state show wide variations. In certain school
districts the percentage of anemic children varied from 80% to 96%;
in an adjoining district the percentage ran as low as 3%. The data
indicate that the percentage of hemoglobin is lowest in the youngest chil-
dren and that the boys in the higher grades have a higher hemoglobin
than the girls of the same age and grade. In a study of the hemoglobin
of children attending a special school it was found that the hemoglobin
values were quite high and that of the 554 children attending this school
only 8% of them could be classed as anemic.
In this study of dietary deficiencies 200 samples of vegetables grow-
ing in different sections of the state have been analyzed for 25 elements
on a Littrow spectrograph. The spectrograph has been calibrated so
that rough estimates varying from .01% to 1% have been made. Chemical
analyses are being made for those elements appearing in quantities too







Florida Agricultural Experiment Station


large to be estimated spectrographically such as Ca, Mg, K, P, hnd Fe.
It has been found that the iron content of vegetables from different parts
of the state varies widely. Thus turnip greens grown on the poorer
types of soil had 90 p.p.m. of iron while those on the better soils had
318 p.p.m.

A STUDY OF THE PATHOLOGIC CHANGES IN TISSUES AND
ORGANS AFFECTED BY DEFICIENCY DISEASES OR
BY TOXIC SUBSTANCES
Purnell Project No. 222 C. F. Ahmann
Because of the reputed dietetic value of the papaya, an investigation
was begun to determine the pharmacological and physiological action of
some of the constituents of the papaya plant and fruit. The pharma-
cological action of papain isolated from the leaves and immature fruits
was studied during the year. Experiments were carried out on pigeons
to determine the antiemetic properties of the enzymes. When emetics
were administered orally, subcutaneously, and intravenously, emesis took
place in most instances regardless of the amount of papain given. In
fact, in several cases the administration of papain seemed to hasten
emesis and render the symptoms more acute.
The next series of experiments was designed to show the effect of
papain as a cardiac stimulant. When isolated frog hearts were irrigated
with 1% to 2% of papain it seemed to strengthen the contractions of
both auricle and ventricle by lengthening the refractory period, diminish-
ing fibrillation and other cardiac irregularities. Papain seemed to have
no effect upon the amplitude of the heart beat. The properties of papain
as a vermifuge for dogs are now being studied.

THE DEVELOPMENT OF QUANTITATIVE SPECTROGRAPHIC
METHODS IN AGRICULTURAL RESEARCH
Purnell Project No. 256 L. W. Gaddum, R. C. Williamson*
and L. W. Rogers
The method for the quantitative determination of zinc in plant ashes
was developed to the practical stage. A preliminary report of the method
has been submitted for publication in the Analytical Edition of the Journal
of Industrial and Engineering Chemistry. In connection with this work
a number of zinc determinations were made on samples of leaf mould,
weeds, etc., gathered in connection with Chemistry and Soils project 220.
A technique (based upon the ratio quantitative principle) for detection
and estimation of 18 elements (barium, strontium, vanadium, chrom-
ium, aluminum, manganese, nickel, cobalt, silver, copper, cadmium, tin,
titanium, bismuth, arsenic, antimony, zinc and beryllium) in biologic
materials was developed. This technique was employed in analyzing
samples of grasses in connection with forage crop work on Animal Hus-
bandry project 133.

MISCELLANEOUS PROJECTS
A Study of the Physical and Chemical Properties of Eggs from Hens on
Experimental Diets. (Cooperative with Agricultural Extension
Service and the Florida National Egg-Laying Contest)
This cooperative project on the physical and chemical properties of
eggs from hens on experimental diets has continued through two laying
Head, Department of Physics. University of Florida.


L







Annual Report, 1935 73

seasons. Approximately 7,000 eggs have been examined. The data show
that such properties as weight, volume, porosity, shell strength, ratio of
thick and thin white of eggs from hens on the different diets, varied
slightly but eggs from individual hens on the same or different diets varied
widely. From this study individual birds were selected for breeding
tests.
In special storage experiments of eggs the following results were
obtained: eggs stored at 34* F., 38 F., and 48* F. were all in excellent
condition at the end of 6 months; eggs preserved in water glass were
unfit for use in 6 weeks; eggs preserved in water glass and kept in an
electric refrigerator were in excellent condition at the end of six months;
eggs stored in an atmosphere of carbon dioxide gave conflicting results.








Florida Agricultural Experiment Station


HORTICULTURE
Work in the department was severely handicapped this year by the
extremely cold weather of December and later cold spells which damaged
citrus fruits so badly as to make the carrying on of much of the cold
storage and maturity work very difficult. Also, due to moving from the
old building and the preparation of a new laboratory, the department was
without laboratory facilities for about three and one-half months, causing
much of the work to be greatly delayed.
The work on the effect of zinc on citrus and tung trees continued to
give outstanding results and the use of zinc sulfate as a corrective for
frenching in citrus and bronzing in tung trees has now become a regular
commercial practice on a large scale.
The work on pecan fertilizers and cover crops has developed far enough
to give very outstanding results in the fields. A bulletin on the effect
of fertilizers was published and one on the effect of cover crops is ready
for publication. In connection with the latter, it is particularly interest-
ing to note that leguminous cover crops in the winter, in addition to the
regular summer legumes, have given outstanding results.
PECAN VARIETY RESPONSE TO DIFFERENT SOIL TYPES,
LOCALITIES, ETC.
State Project No. 46 G. H. Blackmon
General conditions for pecan tree growth were more favorable in
1934 than they had been for several years. The variations in the pro-
ductiveness of different varieties followed the same trends as reported
for previous years. The importance of precocious and heavy yielding
varieties has continued to be emphasized in orchards throughout the pecan
area of the state. The standard non-scabbing varieties have continued to
respond to fertilizers and cover crops, Stuart generally giving less pro-
nounced response than the others.
Summer cover crops, largely Crotalaria spectabilis, continue in favor
with many growers; velvet beans and beggarweed are used over a large
area, while Kudzu is utilized to a less extent. A light disking or mowing
of the summer cover crop to check growth during dry seasons has been
found to give the best results. However, during normal years this opera-
tion should be completed during early August, at the latest.
Zinc Treatments: Rosetted trees 15 to 20 years old have continued
to respond to two pounds of 89% zinc sulfate applied annually to the
soil under the branches. Stuarts, however, have been slower than Curtis,
Moore, Moneymaker, Frotscher and Success in showing normal growth.
Zinc sprays applied to the foliage proved effective in checking rosette,
but were not as lasting as the soil treatments.
Results in growth and condition of trees have been most outstanding
with Curtis on Coxville fine sandy loam soil, which received lime applica-
tions about 19 years ago. Where two pounds per tree of 89% zinc
sulfate were applied to 15 year old Curtis in 1933, and again in 1934,
the trees are now in almost normal growth. Less amounts of zinc sulfate,
however, failed to give such marked results. The soil has received annual
applications of complete fertilizers since 1924.
Twenty year old Moore trees on Norfolk fine sandy loam soil in Jeffer-
son County have responded remarkably well to two pounds per tree of
89% zinc sulfate applied in 1933 and again in 1934, while less amounts
did not produce such satisfactory growth. Moore and Moneymaker 15
year old trees on similar soils in Jefferson County also responded satis-
factorily to zinc sulfate applications at the same rate. These soils also
have received annual applications of complete fertilizers.







Annual Report, 1935


The Stuart trees on all soils have been slow in showing response to
zinc sulfate applications. However, in June of 1935, those on the Experi-
ment Station Minor Farm at Gainesville, where the material has been
applied annually to the soil for three years, showed a decided improve-
ment in the condition of growth over the untreated trees.

COOPERATIVE FERTILIZER TESTS IN PECAN ORCHARDS
State Project No. 47 G. H. Blackmon
Fertilized trees in most experiments continued to show an increased
growth and yield over those unfertilized. Moore trees in Jefferson County
gave the heaviest production of all varieties, while the Moneymaker in the
same orchard failed to produce a crop. The best yields are being obtained
where the owners are growing and returning leguminous cover crops to
the soil.
Curtis and Kennedy trees in Bradford County were damaged severely
by the storm in September, 1933, and a late growth forced that fall.
As a result of this premature defoliation, the trees went into dormancy
in a weakened condition with the food reserves depleted. It would seem,
therefore, that the low vigor of the trees would explain the crop failure
in 1934.
The bloom and subsequent set of nuts was good for the Curtis, Moore,
and Moneymaker, and light to fair for the other varieties in 1935.

VARIETY AND STOCK TESTS OF PECAN AND WALNUT TREES
State Project No. 48 G. H. Blackmon
Pecan trees in the test orchard showed continued improvement in
condition during 1934. The following varieties produced nuts in varying
quantities: Bass, Burkett, Dependable, Farley, James, Kennedy, Money-
maker, Moore, Randall, Rising, Russell, Schley, Stuart, Success, Teche,
and Zink. The bloom was fair to good this spring.
Severe cold injury to many of the trees was caused by early frosts
in November and low temperatures during December 1934. The tops of
three trees (one each of Moore, Schley and Stuart) were killed back almost
to the graft union. Many other trees also showed dead twigs, and in some,
whole branches were killed as a result of the cold. In most instances,
however, the trees are forcing a vigorous shoot growth below the injured
portions of the branches and trunks.
Trees with rosette are showing improvement in condition of growth
following application of two pounds of 89% zinc sulfate. There was
some response in the latter part of the 1934 growing season but the dif-
ference is more noticeable this spring than it was last fall. Black walnut
trees with rosette that received soil applications of 89% zinc sulfate continue
to show normal growth. Zinc sulfate as a spray produced improvement
in growth but not to the same extent as it did when applied to the soil
about the trees.

PROPAGATION, PLANTING AND FERTILIZING TESTS WITH
TUNG-OIL TREES
Hatch Project No. 50 A. F. Camp
Results for the year 1934 of fertilizer tests on eight plots of 12-year-
old trees are given in Table 4.
The period from December 8 to December 13, 1934, subjected tung-oil
trees to severe temperatures, the lowest being 16* F. (official) on Decem-
ber 12, 1934. In general, cold damage to trees in the Station's plantings
as a result of these temperatures was slight. Observations of various







76 Florida Agricultural Experiment Station

plantings in different localities substantiate those previously made that
there is a direct correlation between the relative dormancy, growth and
vigor of the tree and cold damage. Trees that are dormant and have
made a strong and thrifty growth showed little if any damage when
exposed to the above temperatures, while others were injured in direct
proportion to their lack of thrift and vigor. This varied from the killing
of small twigs and limbs to where the tree was killed.
TABLE 4.-TUNG OIL YIELD AND TREE SIZE (AVERAGES), 1934. TWELVE-
YEAR-OLD TREES.
Height Spread Cross-section area Yield in air-dry
Plot* (ft.) (ft.) trunk (sq. in.) seed (lbs.)

1 15.2 22.0 51.95 11.0
2 14.2 20.0 41.50 15.2
3 15.1 22.4 50.69 13.8
4 12.2 19.1 30.80 10.4
5 14.4 21.3 47.60 16.4
6 13.3 20.1 35.63 14.4
7 15.7 22.2 46.55 17.3
8 15.2 22.2 41.99 12.7

12 trees to plot, except Plot 4, which has 6 trees.
Fertilizers
Plot 1-Steamed bonemeal and cottonseed meal, equal amounts, 8 lbs., 1934.
Plot 2-5-8-4 mixture (same as No. 5) with addition of 4 lbs. of air-slaked
lime 4 times during 12 years. No fertilizer applied until 1930.
Plot 3-5-8-4 mixture (same as No. 5) with one application of lime as above
at planting, 8 lbs. 5-8-4.
Plot 4-Check-no fertilizer.
Plot 5-5-8-4 mixture of 2% nitrate of soda; 1% sulfate of ammonia;
2% cottonseed meal; 8% superphosphate; 4% muriate of potash,
8 lbs., 1934.
Plot 6-Stable manure, 36 lbs.
Plot 7-5-8-4 mixture of 3% nitrate of soda; 2% cottonseed meal; 8%
superphosphate; 4% muriate of potash; 8 lbs., 1934.
Plot 8-Steamed bonemeal, 8 lbs., 1934.
Temperatures of 26* F. (official) February 28, 1935, and 30 F. on
March 1, 1935, came while the trees were at the height of their bloom,
and resulted in almost complete failure of the 1935 crop.
Additional field plantings were made in February 1935 of crosses in
which the cluster type was used as a female parent and the No. 9 tree as
the male parent. Plants from seed which were produced as a result of
close pollination of both types were also planted at this time.

TESTING OF NATIVE AND INTRODUCED SHRUBS AND ORNAMENTALS
AND METHODS FOR THEIR PROPAGATION
Hatch Project No. 52 A. F. Camp and G. H. Blackmon
Ornamental trees and shrubs were subjected to extremes of temperature
from December 8 to December 13, 1934, the lowest recorded temperature
being 16* F. (official) on December 12. On the whole, injury to orna-
mental trees and shrubs in this area was quite severe. However, the
various species of plants used as ornamentals showed a wide variation
in the amount and severity of injury, ranging from none to where the
entire plant was killed to the ground.


L







Annual Report, 1935 77

The relative amount and severity of injury, if any, is given below.
This classification is, of course, relative and may not entirely fit any one
plant. Also, due to the difference in age, location and vigor of observed
plants of any given species, that particular plant may fall under more
than one of these headings.
No Injury
FPI No. 24659 Pistacia chinensis
." 36164 Poupartia axillaris
24638 Ilex cornuta
41261 Agyneja impubes
62256 Cotoneaster salicifolia flocossa
34359 Sterculia platanifolia
56679 Aleurites montana
S 62553 Prunus serotina
S 22985 Zelkova serrata
S 61000 Ulmus pumila
S 62418 Euonymus Bungeanus
78658 Quercus acutissima
S 70973 Cornus sp.
S 21617 Chionanthus retusa
S 71304 Cudrania tricuspidata
57080 Juniperus cedrus
Foliage Only Injured
A. Slight Injury
FPI No. 76927 Pillyrea latifolia
73844 Cupressus lusitanica glauca
S" 6317 Ligustrum ionandrum
B. Medium Injury
FPI No. 33500 Jasminum Beesianum
78338 Escallonia glutinosa

Injury to Plant
A. Twigs Killed
FPI No. 56302 Cornus capitata
56318 Ligustrum sp.
B. Twigs and Smaller Limbs Killed
FPI No. 51503 Callistemon citrinus
56824 Ligustrum sp.
C. Branches and Main Limbs Killed
FPI No.011714 Casuarina tenuissima
90679 Casuarina Cunninghamiiana
43947 Koelreuteria formosana
58394 Castanopsis delavayi
D. Killed to the Ground
FPI No.010778 Casuarina montana
93778 Casuarina glauca
90682 Casuarina strict
92485 Casuarina suberosa
92483 Casuarina lepidophloia
90679 Casuarina Cunninghamiana
63797 Vitex quinata
63771 Flacourtia rukam







Florida Agricultural Experiment Station


FPI No. 89402 Cordia alba
75718 Ceratostigma Willmottianum
It 64762 Elaegnus philippensis
76776 Bolusanthus speciosa
t 73834 Callitris cupressiformis
92303 Actinidia chinensis x arguto
87495 Sterospermum sp.
66293 Jasminum heterophyllum
t 28684 Diospyros montana cordifolia
25170 Strychnos spinosa
58394 Castanopsis delavayi

Approximately 15 new species of both shrubs and trees have been
added for testing. Propagation tests will be run on these to obtain in-
formation as to the best method for local conditions.
During the past year a survey has been made of the methods of
cultivation, propagation, fertilization, harvesting, and storage of the
principal bulb crops grown on a commercial scale in Florida.
COVER CROP TESTS IN PECAN ORCHARDS
State Project No. 80 G. H. Blackmon
A cover crop combination of either Austrian peas or hairy vetch in
winter with Crotalaria spectabilis in summer continued to produce the
most growth and yield in pecan trees. There has been no appreciable
difference in the pecan production where either of the two winter legumes
was grown and returned to the soil, as the trees in each more than doubled
the yield of those where no cover crop was planted during 1932-1934.
Growing oats in winter and Crotalaria spectabilis in summer and return-
ing all material to the soil failed to cause the trees to yield as heavily
as where no cover crop was planted, except with the Stuart, in one instance.
The trees responded to sulfate of ammonia applications except with
the Stuart, where the winter non-legumes were grown. The increased
production was heaviest for both Frotscher and Stuart where the winter
legumes of either Austrian peas or hairy vetch were grown, followed by
Crotalaria spectabilis in summer. However, Frotscher trees generally
have yielded much heavier than the Stuart, under like treatments.
The 1934 yields of both varieties followed the same general trend as
for the whole experimental period. The sizes and kernel percentages
of the nuts produced under the different treatments were in about the
same relation as previously reported.
Studies on effects of cover crops on the growth and yield of pecans
under the different treatments have been brought together and compiled
in manuscript form. The results cover seven years' records, and show
that there were no appreciable increased yields in the all-legume plots
until the organic material produced during four years of annual cover-
cropping had been returned to the soil. Therefore, the time required
to revive trees in low vigor when of productive varieties on suitable pecan
soils is indicated to be three to five years.

PHENOLOGICAL STUDIES ON TRUCK CROPS IN FLORIDA
State Project No. 110 F. S. Jamison
Work on this project was a continuation of that initiated previously.
New varieties of potatoes developed by the U. S. Department of Agriculture
were grown in test plots near Arcadia and on a commercial scale in the
Hastings area. The results of the trials are given in Table 5. Katahdin


L








Annual Report, 1935 79

continued to be outstanding in the production of smooth No. 1 potatoes.
Seedling No. 31914 gave a larger total yield but many of the potatoes
of No. 1 size were very rough. Chippewa appeared to be very susceptible
to bacterial wilt. The tests at Arcadia and Hastings were severely in-
jured by cold weather.
TABLE 5.-RESULTS OF POTATO VARIETY TESTS.
Yield, Bushels per Acre
Variety Where Grown No. 1 1 No. 2 I Total

Katahdin ................ Arcadia.............. 159 10 169
Katahdin ................ H..........Hasti ............ 147 14 161
No. 31914............. Arcadia............ 161 35 196
No. 31914................ Hastings............ 195 15 210
Chippewa ................ Arcadia.............. 66 35 101
Chippewa ......... Hastings............ 133 14 147
Bliss Triumph........ Arcadia.............. 79 23 102
Spaulding Rose...... Hastings............ 144 19 163


A test comparing Louisiana grown certified with certified seed pro-
duced in Maine showed Maine seed definitely superior. Maine-grown
Katahdin seed planted in November at Arcadia produced 169 bushels an
acre as compared to 77 bushels an acre produced from Louisiana-grown
seed.
In an effort to secure a better heading type of Iceberg lettuce, 24 lots
of New York lettuce, the product of selections begun in 1933, were planted
at Gainesville and Palmetto. A very poor stand of plants at Palmetto due
to dry, hot weather at planting time caused the abandonment of the trial.
Five lots of the 24 planted at Gainesville showed decided superiority in
ability to form firm heads. Selection is being continued within each of
the 24 lots. Seed has been successfully grown at Gainesville from the
desirable strains.
Eighty-three varieties of vegetables other than lettuce and potatoes
were planted at Gainesville. Varieties of tomatoes, eggplant, pepper, snap
beans, Lima beans, muskmelons, watermelons and cucumbers were grown.
All were affected by the extremely dry weather that prevailed during
the spring growing season. All tomato varieties were grown pruned
and staked and unpruned and unstaked. The staked and pruned plots
showed decidedly more blossom-end rot than did the unstaked and unpruned
ones. Harvesting has not been completed on these tests. Varieties that
appear to be worthy of further trial are the Straight-8 cucumber, Cali-
fornia Wonder pepper, Scarlet Dawn, Rutgers and Kilgore's Special
tomatoes, and Stringless Black Valentine beans. The Rocky Dew variety
of muskmelon is worthy of special attention. This variety appears immune
to downy mildew. The fruit vary widely in quality, color of flesh and
size, but all plants appear to be immune to mildew. An attempt is being
made to select desirable commercial types from this variety. Further
results will be available on these trials when harvesting is completed.

FUNDAMENTAL PHYSIOLOGY OF FRUIT PRODUCTION
State Project No. 111 A. F. Camp
Mulched citrus plots continued to show marked superiority in growth
and color, while the "no cultivation" plots seemed to be slightly poorer
than the cultivated plots, though the difference was not great. It was
expected that yield figures would be available but the cold froze the fruit








Florida Agricultural Experiment Station


to such an extent that it was not worth harvesting and no figures could be
obtained. Fruit in the mulched plots appeared to be a little greener in
color in the fall, and a little coarser in texture, but the cold weather
occurred too early to determine whether this would carry on into harvest
time.

RELATION OF NITROGEN ABSORPTION TO FOOD STORAGE AND
GROWTH IN PECANS
Adams Project No. 165 G. H. Blackmon and A. F. Camp
Pecan seedlings were grown during 1934 in sand and soil cultures, using
the nutrient solutions given in the 1934 annual report, with and without
additions of boron. Twelve six-gallon glazed earthen jars with drainage
provided near the bottom were used as containers for the cultures; six
for sand and six for soil. Builders' sand was used for the sand cultures
and a good grade of Norfolk for the soil cultures. The jars were arranged
in four groups of three each so that the effects of boron in the cultures
could be studied. To three jars each of sand and soil one-half part per
million of boron as boric acid was added at each solution renewal, while
to the other set boron was not added. Iron was supplied to all cultures
weekly in sufficient quantities to meet the requirements of the plants.
The pecan seedlings were set in the cultures May 1934, and removed, dried
and weighed February 1935.
Nitrate Absorption: Leachings from the cultures were collected during
the growing season and the nitrates and the pH for each determined.
Leachings from both the sand and soil cultures showed that addition
of boron apparently reduced the amount of nitrates leached. This would
indicate that the seedlings receiving boron had a higher absorbing capacity
for nitrates. Less nitrates were recovered in the sand cultures than in
the soil cultures.
Growth: The growth of the seedlings during 1934, as determined by
the dry weights, was greater for sand than for the soil cultures. The
increase in dry weight of the whole seedlings as well as for the tops and
roots separately was greater in each instance where boron was added with
the nutrient solution to either sand or soil cultures. The increase with
sand, however, was only 32.1 percent, while with the soil it was 162.5 per-
cent for the whole seedling.
Work on the citrus seedlings was greatly reduced, while the pecan work
was being pushed during the past year. A large number of citrus cultures
are now being grown so as to have good-sized plants ready for the work
the coming fall.
VARIETY TESTS OF MINOR FRUITS AND ORNAMENTALS
State Project No. 187 A. F. Camp and H. S. Wolfe
Avocados: All of the Mexican and Mexican hybrids under test were
severely damaged by cold, some of them being killed to the ground. The
three most desirable varieties were least injured and buds of these are
being propagated for further trial in the field.
Blackberries: The Marvel blackberry showed no winter injury and, in
spite of the fact that the plants were infected with the double-blossom dis-
ease, produced a fair crop of fruit. Both Strains 1 and 2 of the Advance
blackberry produced a good crop of fruit this year. These plants showed
slight winter injury. The Youngberry made poor growth this past year,
evidenced considerable winter injury, and the crop was very light.
Other plantings are being continued but showed no unusual results the
past year.







Annual Report, 1985


STUDY ON THE PRESERVATION OF CITRUS JUICES AND PULPS
State Project No. 189 A. F. Camp
This project could not be continued extensively this year, due to the
moving of the laboratory and also due to the fact that the entire citrus
crop at Gainesville was destroyed by cold before it matured and it was
impossible to get satisfactory fruit in the central part of the state without
a great deal of difficulty. It was thought better, therefore, to carry on
other projects in more detail than to work on this one for the past year.
COLD STORAGE STUDIES OF CITRUS FRUITS
Purnell Project No. 190 A. F. Camp and A. L. Stahl
Continuing the studies on the prevention of pitting, a large number
of new pre-treatments and coatings for fruit were tried. Both oranges
and grapefruit were kept for four months with very little pitting and
decay when treated with the outstanding treatments and then sold com-
mercially, the demand exceeding the supply. On the basis of prevention
of moisture loss, pitting, decay and retention of good appearance, the out-
standing treatments were a commercial emulsion of carnauba wax (80%)
and paraffin (20%), and borax with moisture-proof wraps.
New types of moisture retentive wraps made from cellulose derivatives
and metal foils were tried on several hundred boxes of both oranges and
grapefruit. These continued to show the superiority of moisture-proof
wrappers when placed in ordinary cold storage. The optimum storage
temperature was found to be 37% F. Moisture-proof box liners made in
the form of large bags which would fit the half of an orange packing box
and allow sufficient top for folding over and sealing were found to be as
efficient as individual moisture-proof wrappers and cost about one-tenth
as much. The combination tissue wrap and moisture-proof liner proved
most satisfactory. Moisture-proof cellophane bags holding 6 and 12 oranges
apiece were also found to be as efficient as individual wraps.
Studies of the use of gases in fruit storage were continued and former
results confirmed. Ordinary air and nitrogen proved to be superior to
oxygen or hydrogen in keeping citrus fruit in gas-tight containers. Apply-
ing this idea of gas-tight storage to commercial storage of citrus, it was
found that fruit held in ordinary still air inside the tank at the same
temperature (37 F.) as that held at ordinary storage where there was
a constant ventilation kept one month longer and in a better condition
with much less loss from decay, pitting and other physiological break-
downs. When the carbon dioxide content was kept low and the humidity
high within the large air-tight container which held 150 boxes of fruit,
both oranges and grapefruit kept four months in splendid condition and
sold on the market in preference to California fruit during the late summer
months.
A large number of frozen oranges and grapefruit were placed in storage
to determine their keeping quality in cold storage. It was found that those
placed in storage at 32 and 37% degrees F., when still in the frozen con-
dition, and thawed out gradually, were eatable for two months. Those
placed in storage six, 12 and 24 hours and one week after thawing out
on the tree did not keep as long as those picked while still frozen, but
kept much better than those left on the tree and were eatable for one
month. No detrimental effects were obtained from eating cold-stored
oranges which had been frozen on the tree. All the fruit had to be utilized
directly as it was removed from storage, as physiological breakdown and
decays occurred very rapidly thereafter.








00
tw










TABLE 6.-PHYSICAL AND CHEMICAL CHARACTERISTICS OF ONE THOUSAND AND TWENTY ORANGES FROM ONE TREE.

No. ANALYSES OF WHOLE FRUIT ANALYSES OF THE JUICE
Fruit I Sp. Peel No. Sp. % Sugars
Ana- Total Gr. % % % Thick- Diam. No. of Vol. Gr. % Free
lyzed Size (mm.) Weight of Peel Pulp Juice Seed nes of of Se- of of Citric pH Re- Hydro- Total
Ht. Diam. (gms.) Fruit (mm.) Core Seeds ments Juice Juice Acid during lyzable

Minimum.. 51.0 56.0 107.0 .9285 10.8 11.7 38.5 0.0 2.0 5.0 0.0 8.0 41.1 1.042 0.7 8.2 8.16 2.41 6.09
Maximum.. 87.0 84.0 274.8 1.0017 80.8 88.6 77.4 5.1 5.0 14.0 86.0 18.0 162.5 1.066 2.7 4.8 5.88 5.58 10.75

Average 1,020 69.2 70.8 186.4 .9649 21.1 20.3 56.7 2.2 8.2 9.0 15.1 10.8 100.0 1.052 1.8 8.6 4.80 3.85 8.17

*Measurements made with calipers. c.

ci.







Annual Report, 1935


CITRUS MATURITY STUDIES
Purnell Project No. 237 A. L. Stahl
Analytical work on 1,020 oranges from one tree was completed and
the results are given in Table 6.
Comparisons of the analytical figures showed many interesting results.
For example, the total sugar content was found to be highest in russet
fruit and lowest in the largest fruit; fruit borne in clusters had a higher
sugar content than fruit borne singly; fruit from south side of tree higher
than fruit from north side; fruit from outside of tree higher than that
borne inside; and blossom end of fruit higher than the stem end. The
percent acid varied in fruits picked from different parts of the tree but
not to the degree of sugar variation.
Data obtained in these analyses are being used as a basis for deter-
mining significance of results in the regular work on maturity and also
as a basis for sampling methods.
Histological study of fruits at the various stages of growth is being
continued on the same basis as last year, and several years' work will be
necessary in order to obtain usable results.

STUDIES ON THE EFFECT OF ZINC AND OTHER UNUSUAL MINERAL
SUPPLEMENTS ON THE GROWTH OF HORTICULTURAL CROPS
Purnell Project No. 238 A. F. Camp
Work on the use of zinc on tung trees was summarized up to the fall
of 1934 in Bulletin 273. Practically all of the plots reported on there
are being continued in order to determine ultimate effects on growth and
yield. Tung trees on some soils were found to be slowly responsive to
soil applications of zinc sulfate and spray plots were started similar to
those used on citrus. These plots developed some interesting information
with regard to sulfur compounds on tung trees. Where the lime-sulfur-
zinc sulfate spray was used, the trees were completely defoliated. Later
it was reported that lime-sulfur spray drifting from adjoining Satsuma
orange trees caused similar defoliation.
A number of new forms of zinc were tried, in an effort to find a cheaper
source of zinc for commercial use in groves, but none, so far, have been
as good as zinc sulfate. Studies are also being made on the foliage of
the tree to determine the effects of zinc on the character and composition
of foliage.
In citrus, the superiority of sprays over soil treatments in the main
citrus growing areas still continues. Five to 10 pound treatments on the
soil gave relatively slower response than did one spraying, but experiments
are being continued to determine whether the soil treatments will give,
ultimately, a more lasting correction. Experiments with sprays carrying
various concentrations of zinc sulfate indicated that 5 pounds of zinc
sulfate (ZnSOI.1H2O) per 100 gallons would give about as good results
as five pounds of zinc sulfate for 50 gallons, and the more dilute spray
showed less residue left on the leaves, and this would probably tend to
reduce the scale infestation due to residue. Sprays of zinc sulfate, without
the addition of alkaline materials such as lime or lime-sulfur, continue to
give some damage to foliage and, particularly, to young fruit, and cannot
be recommended. Combinations of zinc sulfate with lime-sulfur and bor-
deaux are being carefully studied from all angles, particularly with regard
to the changes in composition of the pest control sprays.
So far, one spraying seems to be about as effective as two or more
sprayings and best results with sprays are obtained when tree and soil
conditions are such as to induce tree growth. Sprays put on in August






84 Florida Agricultural Experiment Station

and September of 1934 on groves which were hardened up from drought
and lack of fertilizer failed to show results until the following spring but
did show them at that time. In all experiments, sprays have cured french-
ing, even though there has been a slow response in some instances.
Many of the groves under tests were severely injured by cold and a
few had to be abandoned for the time being. In almost all the groves,
the crop was so badly injured that crop figures were unobtainable. As
soon as the coming crop is harvested, the data on citrus will be assembled
into bulletin form.
FUMIGATION RESEARCH
Project No............. R. J. Wilmot
The bibliography on fumigation was completed, checked and put out
in mimeographed form. It contained 110 pages of references to the use
of hydrocyanic acid gas as a fumigant. Distribution was made to active
workers in the field of fumigation but many additional requests were re-
ceived from research workers and teachers.
A considerable amount of time was given to the development of an
electrical method for determining concentration of hydrocyanic acid gas
in air mixtures, with the idea of developing equipment of a reasonable
accuracy for use in fumigation work generally. An accurate portable equip-
ment of this type would be
III| of great value in aiding the
SII development of new methods
of fumigation, as the pres-
ent methods of analysis are
cumbersome and difficult to
use under field conditions.
It was found that, by
passing air containing hy-
drocyanic acid gas over a
hot platinum wire in a
properly constructed system,
the change in resistance of
the wire due to the burning
of the gas on the surface
of the coil could be used as
a basis for calculating the
concentration of hydrocy-
anic acid gas. After a
great deal of experimental
work, a circuit was devel-
oped, which gave good re-
sults (Fig. 3).
SWork is now being done
Fig. 3.-A bridge circuit developed at on the refinement of this
the Florida Experiment Station which gave system and its adaptation
good results in hydrocyanic acid gas to a portable item of equip-
analysis. ment. Using a system that
could be brought within the
confines of a relatively small box, results were obtained which compared
very favorably with the regular methods of analysis and it is believed that,
with a little additional work, a full portable unit for the determination of
hydrocyanic acid gas in air can be developed.
Work on the cigarette beetle (Lasioderma serricorne Fab.) was continued.


Y






Annual Report, 1935


PLANT PATHOLOGY
During the year 25 approved projects have been under investigation.
In addition to work on these projects, some time has been spent by various
members of the department investigating certain other problems to obtain
information requested by growers and others interested in agriculture for
which no information was available. Some of these problems which have
received attention are the "friendly" fungi attacking scale-insects, com-
parative value of certain new fungicides, and various diseases of introduced
and other crops. Also, considerable time has been spent in consultation
and correspondence concerning disease problems occurring in different sec-
tions of the state.
Numerous requests have been received during the year for information
on the cause and methods for treating new outbreaks of gummosis of citrus
trees, indicating that this disease is much more prevalent than in previous
years. From these requests and the observations made, it appears that
other forms of gummosis than those known for years are very conspicuous
on citrus trees, especially grapefruit, in certain localities where the trees
suffered from drought or cold. In cases where the bark of trees was injured
by cold, it appears that invasion of these injured areas by Phomopsis citri
and Diplodia natalensis aggravated the conditions, resulting in further
dying back and exudation of gum. These organisms were obtained in
culture singly or in combination from most such cases studied. In other
localities where the trees were not injured by cold but had suffered from
drought, gummosis appeared to have its inception in small cracks in healthy
bark which resulted from pressure of accumulated gum underneath. Gum
may exude copiously from such cracks and the recently developed wood
and bark undergoes a gummous degeneration, instead of producing normal
callous tissues. Although Diplodia natalensis, Phomopsis citri and other
organisms have been isolated from such areas, the appearance of the dis-
eased parts indicates that these organisms are not the initial cause of the
trouble.
Approximately 1,200 specimens of fungi and diseased plants were re-
ceived and identified for residents of the state during the year. Many of
these required more or less extensive laboratory treatment for correct diag-
nosis. The desired information was supplied through bulletins and letters.
More than the usual number of plant specimens were received for
identifications. These came from science teachers, amateur botanists and
growers and collectors who are searching for plants of economic value.
Also, a number of specimens of marine algae and other water plants were
sent in for identification by Federal entomologists, who are studying breed-
ing material for pestiferous insects.
A large number of diseased fruits, plant parts, native and exotic plants
and hosts of various insects have been checked and identified for the State
Plant Board.
Probably the most outstanding results of the year are those obtained
in the control of brown rot, Bacterium solanacearum EFS, of potato by
treating the soil with sulfur and lime between crops. This disease has
occurred in certain localities of Florida and other Southern states for
years where it has been a more or less important factor in the culture of
potatoes and other solanaceous crops. The remedy appears feasible to
apply and another year's trials under other soil conditions should give the
final information necessary for general application of the method.
MELANOSE OF CITRUS AND ITS CONTROL
State Project No. 3 Geo. D. Ruehle and W. A. Kuntz
See Report of the Citrus Experiment Station.







Florida Agricultural Experiment Station


DOWNY MILDEW OF CUCURBITS
Adams Project No. 19 G. F. Weber
Work on this project was continued as a study of the effects of bordeaux
spray on the set of cucumber fruits. Half of the 120 plants used in the
test were sprayed at weekly intervals with 2-3-50 bordeaux mixture and
the other half were not sprayed with any fungicide. Daily counts of
flowers over a period of six weeks after the plants began blooming showed
that the sprayed plants produced an average of 1,055.2 staminate and
142.1 pistillate flowers per plant, while the non-sprayed plants produced
an average of 1,345.7 staminate and 161.3 pistillate flowers per plant.
The sprayed plants averaged 113.2 fruits set per plant and the non-sprayed
88 fruits set. By the end of the six-weeks' period, the non-sprayed plants
were practically killed by mildew.
CITRUS SCAB AND ITS CONTROL
State Project No. 24 Geo. D. Ruehle
See Report of Citrus Experiment Station.

INVESTIGATIONS RELATIVE TO CERTAIN DISEASES OF
STRAWBERRIES OF IMPORTANCE IN FLORIDA
State Project No. 126 A. N. Brooks and R. E. Nolen
Numerous observations of poor plants in strawberry fields in the Plant
City section and determinations of reactions of the soils, combined with
experimental tests in the greenhouse, have shown that the reaction of the
soil is directly responsible for failure or poor condition of the plants in
many cases. The best reaction for growth of strawberry plants under
greenhouse conditions was found to be approximately pH 5.5. It is prob-
able that the optimum may vary slightly in either direction with different
types of soil. Plants growing in soils that are too acid are more or less
weak and have poor root systems. The cortex of the roots is dark and
subject to invasion by organisms which finally kill the plants. On a basis
of this information, many growers have profited greatly during the past
two years by incorporating into the soils materials for correcting the soil
acidity before the plants are set. From a comparison of results obtained
and cost of materials, ground limestone appears to be the most economical
to use.
There is a condition of strawberries known as "black root" which ap-
pears in most plantings as the plants grow older but is more pronounced
where the soil reaction is unsuited for the plant. A species of Diplodia
and two bacteria have been found to attack the weakened plants or even
healthy ones and kill them. Sclerotium rolfsii also has been found to attack
young actively growing roots.
STUDIES RELATIVE TO DISEASE CONTROL OF WHITE
(IRISH) POTATOES
State Project No. 130 A. H. Eddins
Sclerotinia Rot: Sclerotinia rot caused by Sclerotinia sclerotiorum
(Libert.) Massey was epidemic in a few potato fields planted in December
but dry weather prevented its occurrence in later plantings. Copper-lime
dust, bordeaux mixture, and lime-sulfur solution applied to the growing
crop gave no control of the disease. Potato leaf and stem rot resulted
from inoculations with S. minor Jagger and S. sclerotiorum but not with
S. intermedia Ramsey.
Fusarium Seed-Piece Decay: The Fusarium which caused an epidemic
of seed-piece decay at Federal Point in 1934 caused only minor damage







Annual Report, 1935


in 1935. Studies have shown the fungus to be Fusarium oxysporum Schl.
or a closely related form. Inoculation tests have demonstrated that the
organism is pathogenic under different soil conditions.
Rhizoctonia: The Katahdin and Bliss Triumph varieties were outstand-
ingly resistant to Rhizoctonia injury as compared to the Spaulding Rose
and Green Mountain in test plots at Federal Point. The Katahdin out-
yielded the Spaulding Rose, its nearest competitor, approximately 10
barrels of marketable tubers per acre. Seedling stem infection was reduced
by planting seed that germinated quickly. Stem infections were also
reduced by treating soil with formaldehyde dust.

INVESTIGATION AND CONTROL OF BROWN ROT OF POTATOES
AND CLOSELY RELATED PLANTS CAUSED BY
Bacterium solanacearum EFS.
State Project No. 143 A. H. Eddins
Outstanding results were obtained in the control of brown rot by treating
the soil in June 1934 with sufficient inoculated sulfur to adjust the reaction
to pH 4.00 or lower and then with agricultural limestone in November to
restore the reaction to pH 5.00 or above. In a series of plots at West
Tocoi treated in this manner, tuber infection was 0.8 percent, while infec-
tion in adjacent non-treated plots was 70.4 percent. The treated plots
yielded 23.9 barrels of healthy tubers per acre and the non-treated plots
0.8 barrels.
The sulfur-limestone treatments made between potato crops at West
Tocoi also gave excellent control of bacterial wilt of eggplants and tomatoes
in 1935.
In plots treated with sulfur in October 1932 and with limestone in
November 1933 tuber infection in 1935 was 4.7 percent, while in adjacent
non-treated plots it was 39.6 percent. The treated plots yielded 53 barrels
of healthy marketable tubers per acre and the non-treated plots yielded
only 10.1 barrels.
In variety tests for resistance to brown rot in heavily infested soil,
the Green Mountain developed 18.6 percent tuber infection, the Katahdin



















Fig. 4.-Experimental plots of potatoes on brown rot-infested soil treated
with sulfur and limestone in the summer and fall, respectively, of 1934.
Staked rows at left are in treated soil, at right in untreated soil.







Florida Agricultural Experiment Station


19.1 percent, the Bliss Triumph 41.2 percent, Irish Cobbler 55.6 percent
and the Spaulding Rose 62.0 percent. In lightly infested soil the Green
Mountain developed 2.3 percent tuber infection, Katahdin 2.2 percent, Bliss
Triumph 3.7 percent, Irish Cobbler 4.4 percent and the Spaulding Rose
6.1 percent.


Fig. 5.-Bacterial wilt of tomatoes is controlled by soil treatments with
sulfur and limestone at West Tocoi. Treated row right, untreated left.


Fig. 6.-Showing comparative resistance of different varieties of pota-
toes to brown rot on infested soil at West TocoT. 1, Katahdin; 2, Irish
Cobbler; 3, Spaulding Rose; 4, Green Mountain; and 5, Bliss Triumph.







Annual Report, 1935


INVESTIGATION AND CONTROL OF A DISEASE OF CORN CAUSED BY
Physoderma zeae-maydis
Purnell Project No. 145 R. K. Voorhees
Some of the inbred lines of corn artificially inoculated with Physoderma
sporangia in 1934 proved to be more resistant to infection than others.
There was also considerable variation in the amount of leaf spot (Helmin-
thosporium turcicum) and a leaf rust (Puccinia sorghi) among the selected
lines. Similar tests were again made with the most resistant lines in 1935,
but the disease has not advanced sufficiently to report any definite informa-
tion on the comparative resistance of the various lines for this season.
Investigations on this disease as originally outlined have been completed
and published. Since the selection of lines for resistance to brown spot
does not merit continuing the project as such, the most promising inbred
lines will be turned over to the Agronomy Department for further trial
in their corn improvement program.

INVESTIGATIONS OF SEEDLING, STALK, AND EAR ROT DISEASES
OF CORN CAUSED BY Diplodia spp.
Purnell Project No. 146 R. K. Voorhees
In connection with studies on ear rots of corn caused by species of
Diplodia, collections of Diplodia from several other hosts have been made
for comparison. These hosts include Acacia sp., Aleurites fordi, Arachis
hypogaea, Buddleia officinalis, Casuarina equisetifolia, C. suberosa, Citrullus
vulgaris, Citrus spp., Diospyros kaki, Ficus carica, Fragaria sp., Gossypium
spp., Hicoria pecan, Ipomoea batatas, Ligustrum sp., Persea americana,
Pistacia chinensis, Prunus sp., Pyrus chinensis, Rosa sp., and Yucca aloi-
folia. Most of these collections appear morphologically similar to D. fru-
menti (Physalospora zeicola) on corn. A Physalospora (perfect stage of
Diplodia) was found associated with the Diplodia on a few of these hosts.
Studies have been in progress to determine, if possible, whether these
Diplodia collections are the same as D. frumenti. This includes morpho-
logical and physiological studies of the various collections as well as at-
tempts to produce their perfect stages by various combinations of single
spore strains in culture and on host plants.

INVESTIGATIONS OF DISEASES OF FERNS AND ORNAMENTAL PLANTS
State Project No. 148 W. B. Shippy
No experimental work was done directly on this project during the
year, as all the time of the leader was devoted to Projects 167 and 253.

INVESTIGATION OF AND CONTROL OF FUSARIUM WILT, A FUNGOUS
DISEASE OF WATERMELONS CAUSED BY Fusarium niveum
State Project No. 150 M. N. Walker
On a basis of their resistance to wilt in the field and greenhouse and
of quality of melon, 235 lots of seed selected in 1934 were given a field
test in 1935. Of this number 74 were individual selections of strain No. 61,
which had proved very promising for resistance and quality. The seed
were planted in March and the season was favorable for development of
wilt and the susceptible strains were almost entirely killed. On the other
hand, a large proportion of the strains of No. 61 and certain selections
of an F. hybrid, No. 437, survived in a healthy condition throughout the
season and the quality of melon was very good. Although there are slight
differences in type and quality of melon as between selections of strain







Florida Agricultural Experiment Station


No. 61, the progeny of each selection appear quite uniform, indicating that
these two characters are pretty well fixed in most of the selections. About
600 self-pollinations and crosses were made during the season to obtain
seed for further trials.

















Fig. 7.-View of a portion of watermelon field planted to different
selections of strain No. 61. This field has been planted to watermelons
several times and the soil is thoroughly infested with the wilt-producing
organism. Note freedom from wilt.

INVESTIGATION OF AND CONTROL OF FUNGOUS DISEASES
OF WATERMELONS
State Project No. 151 M. N. Walker
No experimental work was done on this project, but the experimental
plants used in Project 150 were treated with copper-lime dust for control
of anthracnose and downy mildew. Because of the dry season, these dis-
eases did not appear until late in the season and the dust held them under
control. They did not become epidemic in most commercial fields until
after most of the melons had been harvested. Also, gummy stem blight
and other diseases were of minor importance in commercial fields.

A STUDY OF THE SO-CALLED "RUST" OF Asparagus plumosus
State Project No. 167 W. B. Shippy
So far typical symptoms of rust have been produced artificially only
by exposure of plants to infra red rays. However, it is probable that
intensities of infra red rays sufficient to cause the injury do not occur
in nature. Injuries produced by exposing the foliage to high temperatures,
steam and ultra violet rays are not typical of rust. Experiments are now
in progress to determine whether variations in soil moisture have any
effect in producing the disease.

CONTROL OF WILT OF TOMATOES (Fusarium lycopersici Sace.)
IN FLORIDA
Hatch Project No. 180 G. F. Weber and D. G. A. Kelbert
In 1934 several of the most promising selections of commercial varieties
of tomatoes which had been tested for resistance to wilt for two to four
years were cross-pollinated. The F1 generations of these crosses were


L








Annual Report, 1935


grown during the summer in non-infested soil at Gainesville and seed
was obtained for trials of the F2 generations in 1935 in infested soil at
Bradenton. All of these were more resistant to wilt than the commercial
varieties planted as checks. According to expectation, there was consid-
erable variation in characters of fruit and resistance to wilt among the
F2 plants. Of 14,000 plants set, seed was saved from 77 which showed
the best combination of desirable fruit characters and resistance to wilt.
These will be tested in infested soil next year. Additional crosses were
also made between resistant strains and highly desirable commercial sus-
ceptible strains.

CLITOCYBE MUSHROOM ROOT ROT OF CITRUS AND OTHER
WOODY PLANTS IN FLORIDA
State Project No. 181 A. S. Rhoads
SDuring the year Clitocybe tabescens (Scop.) Bres. has been isolated
from diseased roots of rose boquet (Assonia punctata), laurel oak (Quercus
laurifolia), Brazilian pepper (Schinus terebinthifolius), India rubber (Ficus
elastica), and pithecolobium (Pithecolobium dulce), bringing the total
number of host plants to 98.
The surgical treatment of citrus and other trees attacked by mushroom
root rot, begun in 1930 and continued to date, has proved very effective
in general.
None of the small trees in the lath-house inoculated last year with pure
cultures of C. tabescens and pieces of diseased roots from a tree killed by
this fungus have died from mushroom root rot.
An anatomical study of the xylostroma outgrowths, which frequently
appear as hard, black structures extruded through more or less longitudinal
cracks in the bark of affected plants, has shown their structure to be
practically identical with those described and illustrated by various writers
on roots of trees attacked by the closely related fungus, Armillaria mellea.
These structures originate in outgrowths of the mycelial sheets which
form between the wood and bark. When first formed, they are soft and
whitish to cream-colored, but darken and harden upon exposure to air
until the surface becomes a horny, brittle, black crust. In general appear-
ance, they also resemble the stroma of certain pyrenomycetous fungi.

CONTROL OF BLACK SPOT (Phoma destructive Plowr.) OF TOMATOES
IN FLORIDA AND IN TRANSIT
Hatch Project No. 182 W. B. Tisdale and Stacy Hawkins
Dry weather throughout the season in the Homestead area and a killing
frost on December 12 prevented the accumulation of further conclusive
data on control of this disease. Warm, dry weather prevented development
of black spot on the spring crop and, under these conditions, applications
of 4-4-50 bordeaux and bentonite bordeaux caused reductions in yield of
marketable fruit in the experimental plots. In one series of plots this
reduction amounted to 29 crates per acre. This reduction in yield was
apparently due to the absence of diseases and to the increase in transpira-
tion of the plants following the application of bordeaux during dry, warm
weather. In the highland glades where lack of soil moisture was not so
pronounced, the difference in yield between sprayed and non-sprayed plants
was not so great. In this area certain varieties, 31 MB (USDA), Gulf
State Market, Texas Special and Cooper's Special showed considerable in-
creases in yield as a result of spraying, while the Marglobe, Louisiana
Pink and Hastings Scarlet Globe showed no significant increases.


0








Florida Agricultural Experiment Station


The percentage of black spot which occurred on the non-treated fruit
was too low on the spring crop to obtain any significant results from
fungicidal fruit washes.

A STUDY OF STRAWBERRY WILT OR CROWN ROT
State Project No. 184 A. N. Brooks
Due to the absence of heavy rains in September 1934, final results
were obtained on the spraying experiments for control of crown rot or
wilt caused by Colletotrichum fragariae in the strawberry nurseries. In
these tests the beds sprayed with soluble Palustrex B (15% copper resinate
in an emulsified oil) 1-100 and bordeaux 4-6-50 plus a spreader-sticker,
sodium oleyl sulfate special containing a resin, 1-1000, gave an increase
in number of plants of 18 and 16 percent, respectively. Beds sprayed with
bordeaux 4-6-50 alone and with bordeaux 4-6-50 plus sodium oleyl sulfate
special without the resin yielded practically the same number of plants
as the non-sprayed plots. On the other hand, the yield of plants from
beds sprayed with dry-wettable flotation sulfur (10 lbs. to 100 gal.) plus
the spreader-sticker named above was 9 percent less than that from the
check plots.

INVESTIGATIONS OF. STEM-END ROT OF CITRUS CAUSED BY
Phomopsis citri Faw.
Adams Project No. 185 W. A. Kuntz
See Report of Citrus Experiment Station.

CERTAIN STUDIES OF DECAYS OF CITRUS FRUITS IN STORAGE
Adams Project No. 193 W. B. Tisdale and Erdman West
Work done on this project during this year has been limited primarily
to studies on the comparative effectiveness of various fungicides at tem-
peratures favorable for decays to develop. The fruits were treated within
a few hours after they were picked and then stored at laboratory tempera-
tures for a period of four weeks. More than 12,000 oranges and 5,300
grapefruits have been used in these tests. From 100 to 300 fruits were
used for each treatment and most of the treatments were repeated several
times with three varieties of oranges and two varieties of grapefruit.
Eight percent borax solution was included in each series of treatments
for comparison. After the fruits had dried following treatment certain
lots of the fruits were dipped in a paraffin wax emulsion to simulate
commercial practice. Of the materials used tetra ethyl thiuram mono-
sulfide and a compound containing sodium chlor orthophenylphenate and
sodium tetrachlorphenate proved as effective or more so than borax in
preventing decay, and did not cause as rapid loss of moisture as the borax
treatment. These materials reduced the percentage of decay in oranges
in many instances to less than one-tenth of that occurring in the non-
treated lots. Reductions in the percentage decay of grapefruits were not
so great, but were consistent and significant. The most effective concen-
trations for use under commercial conditions have not been determined.
On the other hand, two materials tested caused an appreciable increase
in the percentage of decay. One of these was an emulsified pine oil which
was used as a wetting agent in the fungicidal solutions. The other was
95% alcohol when dropped on the freshly cut stem. The increase in decay
following these treatments varied from 20 to more than 100 percent.
Waxing the fruits after they were treated with the fungicide materially
reduced the loss of moisture, but also reduced the effectiveness of the
fungicide in preventing decay.








Annual Report, 1935 93

A STUDY OF THE SPRAYING REQUIREMENTS NECESSARY TO
CONTROL GRAPE DISEASES IN FLORIDA
State Project No. 196 K. W. Loucks
Spraying experiments conducted under this project have demonstrated
that stickers do not appreci 5'ly improve the effectiveness of bordeaux in
controlling diseases of grapes. Applications of bordeaux made during the
blooming and fruit-setting periods are most important in controlling black
rot of the fruit. Vines that were not sprayed last year became heavily
infected with diseases this year about three weeks earlier than the sprayed
ones, but there was no apparent difference in the amount of infection by
the middle of June. Ripe rot has not been as successfully controlled as
black rot because of frequent rains during the ripening period. Under
these conditions there is also considerable loss due to a general breaking
down of the fruit, apparently due to yeasts.
INVESTIGATIONS OF A BARK DISEASE OF TAHITI LIME TREES
Adams Project No. 242 W. B. Tisdale
Work done on this project during the year has consisted primarily of
making isolations from affected trees in different localities of the state,
both before and since the freeze in December, and in making inoculations
with the organisms obtained to determine their comparative pathogenicity.
Phomopsis was obtained in the majority of cases from young trees injured
by cold. Invasion appeared to have started in the injured areas on the
branches and trunks and progressed downward, killing the trees to the
buds and in some cases even killing the understock. Such invasion was
usually accompanied by abundant exudation of gum. Comparative cultural
studies are being made with the pathogenic organisms to determine what
species are involved.
All of the trees that were budded in the spring of 1934 at Lake Alfred
and Winter Haven for grove experiments were killed by the freeze in
December. Most of the ones budded at Homestead for experimental tests
escaped cold injury and these were planted in grove formation in May.
A STUDY OF Sclerotium rolfsii Sace. IN FLORIDA: ITS HOST
RELATIONS AND FACTORS INFLUENCING ITS
PATHOGENICITY
State Project No. 247 Erdman West
During the year cultures of Sclerotium rolfsii have been isolated from
six additional hosts, three new ones, making a total of 32 cultures from
different sources that are being maintained at present. The three new
hosts are: Buddleia japonica, Aucuba japonica variegata, introduced plants,
and Dryopteris floridana, a native fern.
Two series of inoculations were made with cultures obtained from
different hosts. In the first, potted plants of bene (Sesamum indicum)
and sesban (Sesbania Emerus) were inoculated with 10 different cultures
and all produced infection within 20 days. In the second experiment potted
plants of annual larkspur (Delphinium ajacis) and pinks (Dianthus var.
Sweet Wivelsfield) were inoculated with cultures from 39 different sources.
One set of larkspur plants was inoculated with sclerotia alone and the
second with the entire contents of the culture tube, including sclerotia,
mycelium and culture media. All except one of the cultures produced
infection and it was apparently dead, as it produced no growth in the pots.
These experiments indicate that there is little, if any, difference in
pathogenicity of cultures of the fungus obtained from different hosts,
provided environmental conditions favorable for infection are provided.








Florida Agricultural Experiment Station


A STUDY OF ROSE DISEASES IN FLORIDA AND THEIR CONTROL
State Project No. 253 W. B. Shippy
In spraying experiments for the control of black spot on 10 varieties
of roses, 50 plants each, it was found that the effectiveness of materials
used ranked in the following order: bordeaux, copper-lime dust, ammoni-
acal copper carbonate, Kolodust (sulfur), Florogard dust (sulfur), lime-.
sulfur and non-treated. No wetting or sticking agents were used with
any of these materials, except where they were incorporated by the manu-
facturers. Effectiveness of the materials was determined at the close of
the season on a basis of the comparative vigor of the plants and amount
of dead wood. However, there was a variation among the varieties in
these characters, regardless of treatment. All of the sulfurs again caused
burning of the foliage during the summer months, and this apparently
reduced the vigor of plants just as if they had been defoliated by black spot.
Because of their injury to the foliage and comparative ineffectiveness
in controlling black spot last year, several of the fungicides have not been
included in the tests this year and several new ones have been added.
Wetting and sticking agents are being tested this year in combination with
some of the fungicides.
Tests with variations in the duration of exposure to sunlight with one-
year-old plants showed that most growth and the least amount of dead
wood developed when the plants were exposed to full sunlight.
Root-knot killed about 150 plants in one experimental plot where the
soil was heavily infested with nematodes.

INVESTIGATIONS OF FRUIT ROTS OF GRAPES
State Project No. 254 K. W. Loucks
Preliminary inoculations made last year to determine the stages at
which the fruit becomes infected with black rot and bitter rot indicated
that black rot infects the fruit only during the blooming and early develop-
ing stages and that from 16 to 36 days are required for the rot to develop
after the fruit becomes infected.
Inoculation experiments conducted this year have given results for black
rot that confirm those obtained last year. The fruit is not yet sufficiently
matured to report final results with bitter rot inoculations.

COLLECTION AND PRESERVATION OF SPECIMENS OF
FLORIDA PLANTS
State Project No. 259 Erdman West and Lillian Arnold
This project was not officially designated as such until October 1934,
but the work has been in progress for many years under supervision of
the Department of Plant Pathology.
A number of specimens of local flora have been collected for study
and preservation. A few trips have been made to more distant parts
of the state to obtain specimens of certain plants occurring in those
localities. Other contributions include: several hundred plants of the
eastern United States from Dr. W. A. Murrill; newly introduced plants
from Mr. Geo. A. Ritchey; a number of specimens of ferns from Messrs.
Robert and Edward St. John and about 400 duplicate specimens in Cuth-
bert's collection from the New York Botanical Garden.
While several thousand specimens are on hand, not over one-fourth of
them have been mounted. Nearly 2,000 sheets have been incorporated
in the herbarium and about 1,500 sheets of the Cuthbert collection have
been interpolated in the general collection. A large number of packets.


L







Annual Report, 1935 95

of fungi have been prepared this year, but only a very few-mostly Myxo-
mycetes-have been distributed in the mycological collections.
The labeling of the genus covers has been completed for the ferns and
phanerogamic plants, but only a very few covers in the mycological section
have been labeled with the uniform type of lettering.
Voluminous collections of Zephyranthes have been made this year by
Prof. H. Harold Hume and these have been mounted and prepared for
distribution.
A large package of specimens of plants in the Scrophulariaceae family
was sent to Dr. F. W. Pennell, a specialist in this group of plants, of the
Philadelphia Academy of Natural Science, who kindly verified or corrected
the identifications.







96 Florida Agricultural Experiment Station

CITRUS EXPERIMENT STATION

The work of the Citrus Station has been continued along lines as
reported in previous years. Despite the handicaps of insufficient lands,
drought and freezing temperatures, progress has been made on the various
projects. For the past several years many lines of investigation demanding
expansion have been severely hindered because of the lack of planting
space, but this land shortage will now be alleviated to some extent through
the recent acquisition of 40 acres of nearby land donated by the Florida
Agricultural Research Institute.
During the freeze of December 11 and 12 a minimum temperature of
23 F., with 14 hours below 32 F., was recorded at this station. The
effects of these low temperatures on trees, fruit and rootstocks of the
numerous station plantings under different experimental treatment have
been carefully studied and the degree of comparative cold resistance
recorded.
An educational exhibit was again made at the Florida Orange Festival
held at Winter Haven January 22-26. The exhibits consisted of numerous
citrus varieties and rootstocks, demonstration models of propagation meth-
ods, specimens of citrus diseases and insects with information as to natural
and artificial control, and of chemical apparatus used in the closely related
field of agricultural chemistry.

MELANOSE OF CITRUS AND ITS CONTROL
State Project No. 3 Geo. D. Ruehle and W. A. Kuntz
Spraying experiments for the control of melanose of grapefruit and
oranges were conducted in 1934 in groves at Babson Park, Largo, Lake
Alfred and Vero Beach. Final results were obtained from these tests
as the fruits were harvested during 1934-35. At Babson Park 3-4-50
bordeaux mixture applied on April 9 was most effective in controlling
melanose, while 1%-2-50 bordeaux followed at 14-day intervals with two
applications of lime-sulfur and basic copper sulfate, 3-100, with oil emul-
sion added, gave practically as good results. Calcium caseinate used as a
spreader with basic copper sulfate reduced its efficiency. Scale increase
was greater where bordeaux mixture was used than where basic copper
sulfate was used.
At Largo old seedling grapefruit trees that were pruned and sprayed
with 3-4-50 bordeaux in April produced 95 percent of fruits that were
practically free of melanose. Trees in the same grove that were pruned
and sprayed with bordeaux in January, non-pruned trees that were sprayed
with 3-4-50 bordeaux in January and in April, and non-pruned trees
sprayed with 1%-2-50 bordeaux in April and in May all yielded lower
percentages of melanose-free fruit. Purple scale was commercially con-
trolled after all these sprays by a single application of oil emulsion in June.
One application of 3-4-50 bordeaux applied on April 19 and 20 to several
varieties of oranges and grapefruits in the Citrus Experiment Station
grove gave better control of melanose than other fungicides applied on
the same dates. Coposil (copper silicate), 3-100, was almost as effective
as the bordeaux. Eleven-year-old grapefruit trees that were pruned and
sprayed produced fruits practically free of melanose, while trees sprayed
but not pruned produced the next highest percentage of melanose-free fruit.
The percentage of melanose-free fruit produced on trees that were pruned
but not sprayed was more than twice as great as that produced on trees
neither pruned nor sprayed.







Annual Report, 1935 97

In grapefruit groves near Vero Beach and Bradenton where dormant
and petal-fall sprays of bordeaux and basic copper sulfate were applied
for control of scab, melanose blemish was also commercially controlled.

INTRODUCTION AND PROPAGATION OF BENEFICIAL INSECTS
State Project No. 13 J. R. Watson and W. L. Thompson
See Report of Department of Entomology.
DIEBACK OF CITRUS
State Project No. 21 B. R. Fudge
In the study of dieback of citrus the distribution of nitrogen, phosphorus
and potassium in normal and abnormal leaves and stems and fruit of trees
with and without copper sulfate treatments have been compared. Five
harvests of different aged shoots were obtained. The significant differences
in the composition of abnormal shoots and those that have had treatments
of copper sulfate are the lower amounts of nitrogen and phosphorus in
the latter tissues. This difference is evident in the juice and in the total
nitrogen and phosphorus of the dried leaves and stems. In the fruit,
"ammoniated" pineapple oranges were found to be higher in nitrogen,
phosphorus and potassium than normal fruit. The fruit from trees that
had been cured of dieback by copper sulfate contain approximately the
same amount of nitrogen and phosphorus as normal fruit.

THE DETERMINATION OF THE EFFECT OF VARYING AMOUNTS OF
POTASH ON THE COMPOSITION AND YIELD AND
QUALITY OF THE CROP
Hatch Project No. 22 R. W. Ruprecht
See Report of the Chemistry and Soils Department.
CITRUS SCAB AND ITS CONTROL
State Project No. 24 Geo. D. Ruehle
In a grapefruit grove near Vero Beach where the trees were not
injured by cold and set a normal bloom, 30 percent of the fruit on non-
sprayed trees was affected by scab in 1935. Trees given only one application
of bordeaux-oil emulsion, either dormant or in the bloom, showed from
2 to 5 percent of scabby fruit. Two applications, dormant and in bloom,
were slightly more effective. Basic copper sulfate and a proprietary
copper-oil spray were about as effective in controlling scab as bordeaux,
but the second application of the proprietary mixture burned the young
fruits severely.
In a grove near Bradenton in which the trees were damaged by cold,
40 percent of the fruits on non-sprayed trees developed scab. Growth
started irregularly in this grove early in January and there was a succes-
sion of blooming periods during the spring months. Results obtained with
a dormant, pre-bloom spray in this case, application of bordeaux-oil emul-
sion and of basic copper sulfate were variable. However, most of the
scab-infection developed on fruits set from late blooms, indicating need
for a second application in the last of the main bloom. Lime-sulfur proved
much less effective than copper-containing fungicides for controlling scab.
Increase in scale-insects was much greater following bordeaux than
basic copper sulfate, where equivalent amounts of copper were used. It
appears, therefore, that it is the amount of residue rather than the copper
that favors the increase of scale. Oil emulsion added to bordeaux for
the dormant spray gives very little reduction in the scale population. Three







98 Florida Agricultural Experiment Station

applications of lime-sulfur spray following a dormant spraying with bor-
deaux adequately controlled light to moderate infestations of scale-insects
in groves near Bradenton and Vero Beach, although the applications made
in April burned as much as 17 percent of the fruits. Dry lime-sulfur with
bentoniite sulfur added controlled scale equally well and burned a lower
percentage of the fruits.

CITRUS PROGENY AND BUD SELECTION
State Project No. 26 J. H. Jefferies
(Cooperative with Bureau of Plant Industry, U.S.D.A.)
This project was initiated in 1922 and the planting now consists of 54
citrus selections. The grove is being carried as in former years, accurate
and detailed record being kept of yield and of tree and fruit characters.
Budwood from the trees having the best performance records is available
to growers and nurserymen.

PROPAGATION EXPERIMENTS WITH CITRUS PLANTS OF
VARIOUS KINDS
State Project No. 34 J. H. Jefferies
Work is being continued to determine the importance to be attached
to the selection of rootstocks and of budwood for high quality fruit. Seed
selection for more vigorous and uniform rootstocks and the effect of trans-
planting of seedlings are also under investigation.
Further experiments have been conducted on substitutes for the waxed
cloth commonly used in budding. Rubber bands, cotton string or thumb-
tacks with waxing, and a gum by-product of cottonseed oil manufacture
have been given thorough trials, the rubber bands at this time proving the
most satisfactory.
A new method of topworking citrus trees has been developed wherein
a wedge-shaped piece, about 2 inches transversely and 7 inches longitudin-
ally, is removed from the base of the trunk and the scion inserted at the
cambium on the lower or transverse cut. The scion used is about pencil
size and held in place with one or two half-inch brads. Wax is applied
to all cut surfaces and the whole then banked with moist sand for a period
of about two weeks. As the scion grows the trunk is used as its support,
and the head of the original tree is gradually removed with the scion's
development. Advantages apparent are cold protection afforded by ease
of banking, possibility of obtaining a partial crop from the original tree
while the scion is developing, and the probability of little detrimental
effect on the root system in the exchange of tree tops.
Hybridizing of acid fruits has proceeded along the lines of previous
years. Over 850 hybrids of limes, lemons, limequats and calamondins have
been produced and many budded into other rootstocks to hasten fruiting.
The parentage of the hybrids is as follows, some of those preceded by an
asterisk having fruited:
Villafranca lemon x Rangpur lime
Villafranca lemon x Mexican lime
Villafranca lemon x Jamaica lime
Genoa lemon x Rangpur lime
Genoa lemon x Lakeland limequat
Genoa lemon x Sperriola lemon
Genoa lemon x Jamaica lime
Genoa lemon x Calamondin
Meyer lemon x Rangpur lime
Meyer lemon x Key lime




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