• TABLE OF CONTENTS
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 Front Cover
 Title Page
 Table of Contents
 Letter of transmittal
 Board of control and staff
 Main
 Index














Group Title: Florida Agricultural Experiment station, report for the fiscal year ending June 30th.
Title: Report for the fiscal year ending June 30th
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Permanent Link: http://ufdc.ufl.edu/UF00005173/00026
 Material Information
Title: Report for the fiscal year ending June 30th
Series Title: Report for the fiscal year ending June 30th.
Physical Description: 40 v. : ill. ; 23 cm.
Language: English
Creator: University of Florida -- Agricultural Experiment Station
Publisher: University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1930
Frequency: annual
regular
 Subjects
Subject: Agriculture -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
 Notes
Statement of Responsibility: Florida Agricultural Experiment Station.
Dates or Sequential Designation: 1905-1930.
 Record Information
Bibliographic ID: UF00005173
Volume ID: VID00026
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 - AMF8112
oclc - 12029638
alephbibnum - 002452807
 Related Items
Preceded by: Report for financial year ending June 30th
Succeeded by: Annual report for the fiscal year ending June 30th ...

Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Title Page
        Page 1
    Table of Contents
        Page 2
    Letter of transmittal
        Page 3
    Board of control and staff
        Page 4
    Main
        Page 5
        Page 6
        Page 7
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    Index
        Page i
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        Page iv
        Page v
        Page vi
        Page vii
        Page viii
Full Text








UNIVERSITY OF FLORIDA



AGRICULTURAL EXPERIMENT

STATION




REPORT FOR THE FISCAL YEAR ENDING
JUNE 30, 1930






CONTENTS PAGE

REPORT OF DIRECTOR ........................... .................... .... ..... 5
REPORT OF BUSINESS MANAGER .........................----............ --- 15
PUBLICATIONS .............................................................. ................ 19
REPORT OF THE LIBRARIAN............................................................. ...... 25
AGRICULTURAL ECONOMICS ................................-- ...............-------....- 27
General farming survey, 27; citrus transportation costs, 28; dairy farming study.
28; cotton grade and staple estimates and primary market price study, 29; truck
crop competition study, 30; pecan study, 31; farmers' cooperative associations, 32.
AGRONOMY .......................-... .. ........................ 33
Pasture experiments, 33; fertilization of pasture grasses, 34; lysimeter studies on
pasture grasses, 36; growth behavior and composition of Bahia grass, 36; lawn
and golf grass studies, 187.; variety test work with farm crops, 37; crop adapta-
tion tests, 37; ratio of organic to inorganic nitrogen in mixed fertilizer for cot-
ton, 38; sources of nitrogen and rates of application as top-dressing for oats, 39;
crop rotation studies. 39; corn selection and breeding, 39; effect of time of plant-
ing corn on silage and grain yield, 40; corn fertilizer experiments, 41; peanut
and corn fertilizer experiments, 41; effect of gypsum on peanuts, 42; peanut
breeding, 42; effect of potash on yield and quality of peanuts, 43; date of seeding
and phosphate requirements of winter legumes and their effect on subsequent crops,
43; winter legume studies, 45; summer cover crop studies, 46; green manure, 47.
ANIMAL HUSBANDRY ........................................ ......- .- .................. 48
SDairy herd management, 48; relation of conformation and anatomy of dairy cow
to her milk and butterfat production, 48; soybean silage for dairy cows, 49; defi-
ciencies in cattle feeds, 50; swine herd management, 50; grazing vs. dry lot feed-
ing for pork, 51; fattening fall pigs for spring market, 51; grazing for fattening
beef, 51; comparative beef cattle grazing studies, 52; cost of wintering steers,
53; anaplasmosis in cattle, 53; paralysis of the domestic fowl, 54; kidney worm
of swine, 55; diagnostic laboratory report, 55.
CHEMISTRY ............................................... .................. ...... ............ 56
Dieback of citrus, 56; effect of varying amounts of potash on yield and quality
of citrus, 57; fertilizer requirements of satsuma oranges, 57; effect of potash
carriers on growth, yield, and composition of crop, 57; fertilizer requirements of
citrus on muck, 58; composition of pecans as influenced by fertilization and soil
types, 58; the cause of poor crop growth following liming sandy soils, 58: effect
of various fertilizer formulas, 59; concentrated fertilizer studies, 60; effect of
green manures on soil composition, 60; fertilizers and soil amendments, tomatoes,
61; effect of fertilizers and soils on composition of truck crops, 61; iodine con-
tent of Florida crops, 62; decomposition of forest, range, and pasture growths, 62.
COTTON INVESTIGATIONS .......................................... ..................... ..- 63
Variety testing and breeding, 63; spacing and time of planting, 64; control of in-
sects, 64; rust, seedling diseases, wilt, 65; nutrition and growth, 66; inheritance, 66.
ENTOMOLOGY ........ ....................................................... ......-- 67
Velvet bean insects, 67; flower thrips, 67; root-knot, 67; beneficial insects, 68:
plant bugs on citrus and truck crops, 68; bean jassid, 69; citrus aphid, 69; de-
ciduous fruit and nut crop insects. 70; life history studies of roach, 71: mealy
bugs, 71; green spider on Asparagus plumosus, 72; insects of ornamentals, 72;
insects and other animal pests of watermelons, 73.
HOME ECONOMICS ............ ................................................. ....... 74
Organisms which cause spoilage of canned vegetables, 74; chlorophyll and alfalfa
pigments as sources of vitamin A in animal nutrition, 75; constituents of citrus
fruits, loquats, roselle, and guava; pectins, oils, and glucosides, 75; nutritional
status of rural school children, 76: relation of growth to phosphorus, calcium and
lipin metabolism as influenced by the thymus, 76.
H ORTICULTURE ................................... ................. ....... .... ............ 77
Citrus hybrids, 77; rootstocks for satsuma oranges, 78; fundamental physiology of
fruit production, 78; avocado maturity studies, 79: shrubs and ornamentals, 81;
variety, propagation and planting tests of pear, avocado, Japanese persimmon,
fig and other fruits, 81; variety tests of berries, 82; pecan cover crops, 82; reju-
venating pecan orchards, 82; pecan diseases, insects, 83; variety response of pe-
cans to different soil types, localities, etc., 83; pecan fertilizer tests, 83: pecan
and walnut variety and stock tests, 85; grape variety tests, 85; propagating, plant-
ing, and fertilizing tung oil, 85; fumigation and sterilization, 86; phenological
studies, truck crops, 87; mulch paper project, 88.
PLANT PATHOLOGY ............................................ ................. ............. 90
Gumming of citrus, 92; melanose and stem-end rot, 93; citrus canker, 94; citrus
blight or chronic wilt, 95; diseases of citrus aphids, 96; citrus scab, 9 ; downy
mildew of cucurbits, 97; nailhead spot of tomatoes, 98: Stemphylium fungus dis-
eases of tomatoes, 99; strawberry diseases, 100; white potato diseases, 102; corn
diseases, 103; pecan diseases, 105; diseases of ferns and ornamentals, 105: dis-
eases of watermelons, 106.
REPORT OF CITRUS EXPERIMENT STATION.......................-....................... 108
Citrus progeny and bud selection, 108; propagation, 108; new varieties and hybrids
of citrus and near citrus, 109; cover crop and green manure studies, citrus, 109:
variety test, 109; grove cultivation. 111; other research work, 111.
REPORT OF EVERGLADES EXPERIMENT STATION...-....-...-.... ............. 113
Water table conditions, 114; meteorological records, 116: buildings and improve-
ments, 119; landscape and windbreak plantings, 120: forage, truck, and field
crop trials, 121; fruit and forest tree trials. 122; fertilizer experiments, 122:
insects, 124; soils investigations, 124; drainage, 128; diseases, 128; special ele-
ments, 129; sugarcane borer, 130; rodents, 130; sugarcane investigations, 130.
REPORT OF TOBACCO EXPERIMENT STATION ........................................ .... 132
Variety tests of cigar wrapper tobacco for resistance to blackshank, 133; fertilizer
experiments, shade tobacco, 134; effect of certain chemicals on leaf quality of
shade tobacco, 135.
REPORT OF SUB-TROPICAL EXPERIMENT STATION................................. 136
















Hon Doyle E. Carlton,
Governor of Florida,
Tallahassee, Florida.
SIR: I have the honor to transmit herewith the annual report
of the Director of the University of Florida Agricultural Experi-
ment Stations for the fiscal year ending June 30, 1930.
Respectfully,
P. K. YONGE,
Chairman, Board of Control.




Hon. P. K. Yonge, Chairman
Board of Control.
SIR: I have the honor to transmit herewith the annual report
of the Director of the University of Florida Agricultural Ex-
periment Stations for the fiscal year ending June 30, 1930, 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.







BOARD OF CONTROL
P. K. YONGE, Chairman, Pensacola RAYMER F. MAGUIRE, Orlando
A. H. BLENDING, Leesburg FRANK J. WIDEMAN, West Palm Beach
W. B. DAVIS, Perry J. T. DIAMOND, Secretary, Tallahassee

STATION EXECUTIVE STAFF
JOHN J. TIGERT, M.A., LL.D., President IDA KEELING CRESAP, Librarian
WILMON NEWELL, D.Sc., Director RUBY NEWHALL, Secretary
S. T. FLEMING, A.B., Asst. Director K. H. GRAHAM, Business Manager
J. FRANCIS COOPER, M.S.A., Editor RACHEL McQUARRIE, Accountant
R. M. FULGHUM, B.S.A., Asst. Editor

MAIN STATION-DEPARTMENTS AND INVESTIGATORS


AGRONOMY
W. E. STOKES, M.S., Agronomist
W. A. LEUKEL, Ph.D., Associate
G. E. RITCHEY, M.S.A., Assistant*
FRED H. HULL, M.S., Assistant
J. D. WARNER, M.S., Assistant
JOHN P. CAMP, M.S.A., Assistant
ANIMAL HUSBANDRY
A. L. SHEALY, D.V.M., Veterinarian in
Charge
E. F. THOMAS, D.V.M., Asst. Veterinarian
R. B. BECKER, Ph.D., Associate in Dairy
Husbandry.
W. M. NEAL, Ph.D., Assistant in Animal
Nutrition
C. R. DAWSON, B.S.A., Assistant Dairy
Investigations
CHEMISTRY
R. W. RUPRECHT, Ph.D., Chemist
R. M. BARNETTE, Ph.D., Associate
C. E. BELL, M.S., Assistant
J. M. COLEMAN, B.S, Assistant
H. W. WINSOR, B.S.A., Assistant
H. W. JONES, B.S., Assistant
COTTON INVESTIGATIONS
W. A. CARVER, Ph.D., Assistant
E. F. GROSSMAN, M.A., Assistant
PAUL W. CALHOUN, B.S., Assistant
RAYMOND CROWN, B.S.A., Field Assistant


ECONOMICS, AGRICULTURAL
C. V. NOBLE, Ph.D., Agricultural Economist
BRUCE McKINLEY, A.B., B.S.A., Associate
M. A. BROOKER, M.SA., Assistant
JOHN L. WANN, B.S.A., Assistant
ECONOMICS, HOME
OUIDA DAVIS ABBOTT, Ph.D., Head
L. W. GADDUM, Ph.D., Biochemist
C. F. AHMANN, Ph.D., Physiologist
ENTOMOLOGY
J. R. WATSON, A. M., Entomologist
A. N. TISSOT, M.S., Assistant
H. E. BRATLEY, M.S.A., Assistant
L. W. ZIEGLER, B.S., Assistant
HORTICULTURE
A. F. CAMP, Ph.D., Horticulturist
HAROLD MOWRY, B.S.A., Associate
M. R. ENSIGN, M.S., Assistant
A. L. STAHL, Ph.D., Assistant
G. H. BLACKMON, M.S.A.. Pecan Culturist
C. B. VAN CLEEF, M.S.A., Greenhouse
Foreman
PLANT PATHOLOGY
W. B. TISDALE, Ph.D., Plant Pathologist
G. F. WEBER, Ph.D., Associate
A. H. EDDINS, Ph.D., Assistant
K. W. LOUCKS, M.S., Assistant
ERDMAN WEST, B.S., Mycologist


BRANCH STATION AND FIELD WORKERS
L. O. GRATZ, Ph.D., Asso. Plant Pathologist in charge, Tobacco Exp. Sta. (Quiney)
R. R. KINCAID, M.S., Assistant Plant Pathologist (Quincy)
JESSE REEVES, Farm Superintendent, Tobacco Experiment Station (Quincy)
J. H. JEFFERIES, Superintendent, Citrus Experiment Station (Lake Alfred)
GEO. D. RUEHLE, Ph.D., Assistant Plant Pathologist (Lake Alfred)
W. A. KUNTZ, A.M., Assistant Plant Pathologist (Lake Alfred)
B. R. FUDGE, Ph.D., Assistant Chemist (Lake Alfred)
W. L. THOMPSON, B.S., Assistant Entomologist (Lake Alfred)
R. V. ALLISON, Ph.D., Soils Specialist in charge Everglades Experiment Sta. (Belle Glade)
R. W. KIDDER, B.S., Foreman, Everglades Experiment Station (Belle Glade)
R. N. LOBDELL, M.S., Assistant Entomologist (Belle Glade)
F. D. STEVENS, B.S., Sugarcane Agronomist (Belle Glade)
H. H. WEDGEWORTH, M.S., Associate Plant Pathologist (Belle Glade)
B. A. BOURNE, M.S., Associate Plant Physiologist (Belle Glade)
J. R. NELLER, Ph.D., Associate Biochemist (Belle Glade)
A. DAANE, Ph.D., Associate Agronomist (Belle Glade)
FRED YOUNT, Office Assistant (Belle Glade)
M. R. BEDSOLE, M.S.A., Assistant Chemist (Belle Glade)
A. N. BROOKS, Ph.D., Associate Plant Pathologist (Plant City)
R. E. NOLEN, M.S.A., Field Assistant in Plant Pathology (Plant City)
A. S. RHOADS, Ph.D., Associate Plant Pathologist (Cocoa)
C. M. TUCKER, Ph.D., Associate Plant Pathologist (Hastings)
H. S. WOLFE, Ph.D., Associate Horticulturist (Homestead)
L. R. TOY, B.S.A., Assistant Horticulturist (Homestead)
STACY O. HAWKINS, M.A., Field Assistant in Plant Pathology (Homestead)
D. G. A. KELBERT, Field Assistant in Plant Pathology (Bradenton)
FRED W. WALKER, Assistant Entomologist (Monticello)
D. A. SANDERS, D.V.M., Associate Veterinarian (West Palm Beach)
M. N. WALKER, Ph.D., Associate Plant Pathologist (Leesburg)
W. B. SHIPPY, Ph.D., Assistant Plant Pathologist (Leesburg)
C. C. GOFF, M.S, Assistant Entomologist (Leesburg)
J. W. WILSON, Ph.D., Assistant Entomologist (Pierson)
*In cooperation with U. S. Department of Agriculture.










Report for the Fiscal Year Ending

June 30 1930




Dr. John J. Tigert,
President, University of Florida.
SIR: I have the honor to transmit herewith my report on the
work and investigations of the University of Florida Agricul-
tural Experiment Stations, together with the reports of the
heads of the several departments, for the fiscal year ending
June 30, 1930.
Respectfully,
WILMON NEWELL,
Director.


INTRODUCTION
The year covered by the present report is the first of the bi-
ennial period, 1929-31. Under the budget provided by the Legis-
lature for this period a considerable expansion of agricultural
research work was authorized. During the past year the con-
dition of the State Treasury has been such that it has not been
possible to carry forward the entire program of work. We have
tried, under these circumstances, to conserve expenditures
wherever possible and, at the same time, to carry forward the
major part of the research program provided for by the Legis-
lature. This has been a difficult and unusual task and the re-
sults are hard to measure.
At the close of the fiscal year we show an unexpended balance
of $66,555.36 out of a total of $406,895.00 of state funds appro-
priated for the year. From a purely financial viewpoint this
appears to be a saving of more than 16 percent of appropriated
state funds. As a matter of fact, the research work which has
been put aside, or abandoned, in order to reduce our expendi-
tures to the above extent might easily have proved to be worth
many times the amount so conserved. Nevertheless, it has been






Florida Agricultural Experiment Station


necessary for us to do all that we could to relieve the drain upon
the State Treasury and this we have cheerfully done. Some
little part of the balance shown at the end of the present fiscal
year must be spent before the close of the biennium. It will
be our intention, however, to allow as much as possible of this
balance to revert and, if conditions warrant, a similar policy
will be continued throughout the next fiscal year also.
In the program of research work for this first year of the bi-
ennium we have undertaken to carry forward the major pro-
jects already under way. In addition some of the principal lines
of expansion provided for by the Legislature have been taken
care of, viz; the establishment of a Sub-Tropical Branch Station
near Homestead in South Florida; the establishment of a Field
Laboratory near Leesburg for the investigation of diseases and
insect pests of watermelons; the expansion of the work at the
Tobacco Branch Station to provide for research work with the
general crops of that area as well as tobacco and in connection
with which the Board of Control has just purchased a tract of
617 acres of excellent land near Quincy; and the initiation of
sugarcane investigations looking to the development of strains
and varieties better adapted to our needs here in Florida. This
latter work is at present being conducted at the Everglades
Branch Station where conditions are favorable for breeding
sugarcane. Later, as the work develops, field trials will be un-
dertaken at all of our stations and also with growers throughout
the State. In addition to these principal lines of expansion pro-
vided for by the Legislature, the construction of the first unit
of a modern laboratory building at the Everglades Branch Sta-
tion has been authorized and is now under way. The Board of
Control has also authorized the construction of a cold storage
plant for research work in refrigeration on the Horticultural
Grounds at the Main Station, the necessary funds for this plant
being available in the budget of the Horticultural Department.
No attempt can be made here to summarize the progress of
the work during the past year as reported in the following pages.
Particular attention, however, is called to the report of the
Editor on "Publications". Our publications are an excellent
measure of the extent and quality of the work performed and
we have, during the past year or two, begun to reflect in these
the results being accomplished through the liberal appropria-
tions of recent years for agricultural research work. Eleven
bulletins, with a total of 90,000 copies, were published during






Annual Report, 1930


the year and in addition 13 press bulletins were issued and 16
press bulletins were reprinted. In addition it will be noted that
members of the Station staff contributed 22 articles to scien-
tific and other publications during the year. These articles were,
in the main, presentations of certain technical phases of research
work and constituted in every way the equivalent of technical
research bulletins.
The financial resources of the Experiment Station for the past
fiscal year have been as follows:
Federal Adams Fund .................................. .......... $ 15,000.00
Federal Hatch Fund .......................... .......................... 15,000.00
State Funds, Main Station, Gainesville ................... 267,245.00
State Funds, Citrus Station, Lake Alfred .............. 15,950.00
State Funds, Everglades Station, Belle Glade ........ 68,100.00
State Funds, Tobacco Station, Quincy ...................... 25,600.00
State Funds, Sub-Tropical Station, Homestead ........ 15,000.00
State Funds, Watermelon Investigations ................ 15,000.00
Station Incidental Funds, Sales, Etc. ...................... 27,230.52
Total ....................................................................... $464,125.52
Federal Purnell funds, not included above ................ 60,000.00

THE MEDITERRANEAN FRUIT FLY

At the close of the fiscal year ending on June 30, 1929, the
campaign for the control and eradication of the Mediterranean
fruit fly was well under way. It had been necessary to call
heavily on the Experiment Station for the temporary use of
its staff personnel in organizing this campaign and, as stated
in the Annual Report for that year, the work had not proceeded
far enough by the close of the year to make it possible to return
any of these workers to their regular duties at the Station.
At the close of the present fiscal year, June 30, 1930, all Ex-
periment Station workers have been returned to their regular
duties. Some of them, particularly those from the Horticul-
tural Department, were retained on the fruit fly work until
near the close of the year and it will be found, in studying the
reports of progress attached hereto, that certain lines of re-
search work were more or less inactive under the circumstances.
This is to be regretted but it is felt that the emergency created
by the fruit fly infestation fully justified calling these men from
their research investigations, however important they may have
been, to the vastly more important duty of aiding in the cam-
paign to control and, if possible, eradicate this pest and thereby
save to the State one of its most important agricultural indus-
tries.






Florida Agricultural Experiment Station


CHANGES IN STAFF
Marvin A. Brooker, Assistant Agricultural Economist, was
granted leave of absence without pay, October 1, 1929 to May
31, 1930, in order to pursue graduate work at Cornell University.
Paul Calhoun was appointed Assistant in Cotton Investiga-
tions, June 1, 1930.
John P. Camp was appointed Assistant Agronomist at the
Main Station, May 1, 1930.
W. H. Conner was appointed Assistant Chemist in Iodine Re-
search Work, February 3, 1929.
C. R. Enlow resigned as Assistant Agronomist at the Main
Station (also Associate Agronomist, Forage Crops Office, U.S.
D.A.), July 31, 1929.
Dr. J. F. Fudge resigned as Assistant Chemist at the Citrus
Station, September 30, 1929.
Dr. B. R. Fudge was appointed Assistant Chemist at the Cit-
rus Station, November 15, 1929.
R. M. Fulghum was appointed Assistant Editor, September
16, 1929.
Carlos C. Goff was appointed Assistant Entomologist on In-
sect Pests of Watermelons, February 1, 1930. Located at Lees-
burg Field Laboratory,
Dr. L. O. Gratz wafransferred from the position of Associate
Plant Pathologist on Potato Diseases at Hastings, to the position
of Associate Plant Pathologist in Charge of the Tobacco Sta-
tion at Quincy, April 1, 1930.
H. W. Jones was appointed to the synthetic nitrogen fellow-
ship, September 15, 1929.
Randall R. Kincaid was appointed Assistant Plant Pathologist
at the Tobacco Station, July 1, 1929.
R. N. Lobdell was appointed Assistant Entomologist at the
Everglades Station, March 1, 1929.
H. L. Marshall resigned as Assistant Chemist at the Main
Station, May 15, 1930.
E. G. Moore resigned as Assistant Editor, September 15, 1929.
E. R. Purvis was transferred from the position of Fellow in
Chemistry at the Main Station to the position of Laboratory
Assistant in Soils at the Everglades Station, September 1, 1929.
L. A. Richardson was appointed to the International Paper
Company's mulch paper fellowship, September 23, 1929.





Annual Report, 1930


Geo. E. Ritchey was appointed Assistant Agronomist at the
Main Station (also Associate Agronomist, Forage Crops Office,
U.S.D.A.), August 1, 1929.
Dr. D. A. Sanders was transferred from the position of Asso-
ciate Veterinarian at the Main Station to the position of Associ-
ate Veterinarian on Anaplasmosis in Cattle at the Field Labora-
tory at West Palm Beach, October 1, 1929.
Dr. W. B. Shippy was appointed Assistant Plant Pathologist
on diseases of Ferns and Ornamentals, with headquarters at
the Field Laboratory at Leesburg, October 1, 1929.
Dr. Arthur L. Stahl was appointed Assistant Horticulturist
at the Main Station, July 1, 1929.
F. D. Stevens was appointed Associate Agronomist on Sugar-
cane Investigations, with headquarters at the Everglades Sta-
tion, April 1, 1930.
George E. Tedder resigned as Foreman of the Everglades
Station, June 30, 1929.
L. R. Toy was appointed Assistant Horticulturist at the Sub-
Tropical Station, January 1, 1930.
Dr. C. M. Tucker was appointed Associate Plant Pathologist
on Potato Diseases at Hastings, June 1, 1930.
Ross F. Wadkins resigned as Laboratory Assistant in Plant
Pathology at the Tobacco Station, June 30, 1929.
Dr. M. N. Walker was transferred from the position of Assist-
ant in Cotton Investigations to the position of Associate Plant
Pathologist on Watermelon Diseases, with headquarters at the
Field Laboraory at Leesburg, November 1, 1929.
John L. Wann was appointed Assistant in Agricultural Eco-
nomic Research, July 1, 1929.
J. D. Warner was appointed Assistant Agronomist, Coopera-
tive Agronomy Experimental Work, September 15, 1929.
H. H. Wedgeworth was appointed Assocate Plant Pathologist
at the Everglades Station, April 1, 1930.
Dr. J. W. Wilson was appointed Assistant Entomologist on
Insect Pests of Ferns and Ornamentals, with headquarters at
the Field Laboratory at Pierson, January 1, 1930.
H. W. Winsor was appointed Assistant Chemist at the Main
Station, June 14, 1930.
L. W. Ziegler was appointed Assistant Entomologist at the
Main Station, June 1, 1930.







SCOPE OF THE STATION WORK, JULY 1, 1929 TO JUNE 30, 1930
A list of the principal projects carried on during the year is given below, arranged according to
departments. Page reference is given to a brief discussion of the work under each project.
Project
Department Number Name of Project Page
AGRICULTURAL 73 Agricultural Survey of Some 500 Farms in the General Farming Region of North-
ECONOMICS west Florida ............................................................................................................... 27
103 A Stluld nf ithe ona o Tn Prnannrtatinn f i Flnrv .iao +nt C Fruirit n.4it4h Cn nartio.oer


Costs from Other States and Foreign Countries............................................
An Economic Study of Dairy Farming in Florida........................................................
Cotton Grade and Staple Estimates and Primary Market Price Study......................
A Study of Florida Truck Crop Competition .... ...............................................
Economic Study of the Pecan Industry in Florida........................................ ..........
Farmers' Cooperative Associations in Florida .................................. ....................
Peanut and Corn Fertilizer Experiments ......... ........... .....................
Plant Breeding- Peanuts ....... .. .................................... .. ..........................
Pasture Experim ents ........... ............................................... .......................
Lawn and Golf Grass Studies .......... ..... ........................ ...................
Effect of Land-Plaster or Gypsum on Hay and Seed Production of Peanut Varieties
W inter Legume Studies .................... ............................................ ..............
Summer Cover Crop Studies .. ............. ...................................................
Crop Rotation Studies with Corn, Velvet Beans, Sweet Potatoes and Peanuts..........
Variety Test Work with Farm Crops..................... ......................
Sources of Nitrogen and Rates of Application of Nitrogen from the Different
Sources as Top Dressing for Oats....................................................................
Green M anure Studies ....... ....................................................... ................
Growth Behavior and Composition of Transplanted Bahia Grass and Bahia Grass
Under Pasture Conditions .. .................. ..... ...... ........ ... ........
Growth Behavior of Bahia Grass ......... ...............................................
Improvement of Corn Through Selection and Breeding ......................................
Effect of Time of Planting of Corn on Forage and Grain Yields..............................
Crop Adaptation Tests ........... ... .... ........................ .......... ..............
Fertilization of Pasture Grasses .. ......................... ............
The Effect of Potash on the Yield and Quality of Peanuts................................
Date of Seeding and Phosphate Requirements of Winter Legumes and Their Effect
U pon Subsequent Crops ......................................................................... ................
Lysimeter Studies on Pasture Grasses ............... ...................................


28
28
29
30
31
32


AGRONOMY





Department
AGRONOMY
(Continued)
ANIMAL
HUSBANDRY








CHEMISTRY














COTTON
INVESTIGATIONS


Project
Number
159
163
92
119
122
133
135
136
137
140
149
160
21
22

36
37
66
67
93
94
95
96
112
141
161
166

57
74
75
76
77
78
79
101


Name of Project Page
Ratio of Organic to Inorganic Nitrogen in Mixed Fertilizers for Cotton................. 38
Corn Fertilizer Experim ents ..................................... .... ................ ........ ............ 41
Kidney W orm of Swine ................................. ............. ........... 55
Paralysis of the Domestic Fowl.................................................. ................................... 54
The Cost of Wintering Steers Preparatory to Summer Fattening on Pasture.......... 53
Deficiencies in Feeds Used in Cattle Rations ............ ................... ........ 50
Soybean Silage for'Dairy Cows ................................................................. 49
Comparisons of Various Grazing Crops with Dry Lot Feeding for Pork Production 51
The Value of Grazing for Fattening Cattle in Beef Production............................. 51
Relation of Conformation and Anatomy of the Dairy Cow to Her Milk and Butter-
fat Production ........ .. ............... ............ .................. 48
Anaplasm osis in Cattle ..... ................................................... ...................... ...... .....-. ......... 53
Fattening Fall Pigs for Spring M market .................................................. ...................... 51
D ieback of Citrus ......................................................................... ............................ ....... 56
Determination of the Effect of Varying Amounts of Potash on the Composition and
Yield and Quality of the Crop ................ ..................... ........ 57
Determination of the Fertilizer Requirements of Satsuma Oranges..................... 57
Determination of the Effect of Various Potash Carriers on Growth, Yield and Com-
position of Crops ........... .......... ................... 57
Study of Fertilizer Requirements of Citrus Trees when Grown on Muck Soils........ 58
Composition of Crops as Influenced by Fertilization and Soil Types-Pecans........ 58
To Determine the Cause of Poor Crop Growth Due to Liming Sandy Soils.................. 58
Effect of Various Fertilizer Formulas .......................... ....... ...................................... 59
Concentrated Fertilizer Studies ................................................ ............. .................. 60
Determination of the Effect of Green Manures on the Composition of the Soil........ 60
Effect of Various Fertilizer Treatments and of Soil Amendments on Tomatoes ..... 61
Effect of Fertilizers and Soils on Composition of Truck Crops............................... 61
Study of Iodine Content of Florida Grown Crops...............................-............ 62
A Study of the Decomposition of Forest, Range and Pasture Growth to Form Soil
Organic Matter ........................................ .............. .....................6..- 62
Variety Testing and Breeding .....-..................................................................... 63
Field Tests with Cotton-Spacing and Time of Planting Tests ................................. 64
Control of Cotton Insects ...................................................................... .......................... 64
Cotton Physiology--Cotton Rust ............................................. .............--... 65
Cotton Diseases-Seedling Diseases ......................................... .................... 65
Cotton Diseases--Cotton W ilt ......................................... ............. ............ ..... 65
Cotton Physiology-Nutrition and Growth ................................. ................ 66
Studies in Inheritance of Cotton .... .................................................................................. 66








Department
ENTOMOLOGY













HOME
ECONOMICS








HORTICULTURE


Project
Number
7

8
12
13
14
28
60
82
108

155
156
157
162
69

70

71
72

142

44
45
46
47
48
49
50
51
52

58


Name of Project Page
Velvet Bean Insects-Life History Studies and Control of the Velvet Bean Cater-
pillar .................................... ........... .. ....... .............................. ............ ...................... ...... 67
Florida Flower Thrips ............................ ............................... ............................ 67
Root-Knot Investigations .... ............................... .......... ......... ............................ 67
Introduction and Study of Beneficial Insects ............................................ ........... 68
Larger Plant Bugs on Citrus and Truck Crops......................................................... 68
Studies of the Bean Jassid .......................................................................................... 69
The Green Citrus Aphid (Aphis spiraecola) ....................................................... 69
Control of Deciduous Fruit and Nut Crop Insects .................................................... 70
Life History Studies of Pycnoscelus surinamensis L., the Roach Which is the Inter-
mediate Host of Manson's Eyeworm .............. .................................. ........... 71
M ealy Bugs ........................................................................... ...................... .................. 71
Green Spider (Tetranychus bimaculatus) on Asparagus Plumosus .......................... 72
Insects of Ornamentals ................ ................................................. 72
Insects and Other Animal Pests of Watermelons............................. .................. 73
Determination and Identification of Organisms which Cause the Spoilage of Can-
ned Vegetables in the South .......................................... ....... .......... 74
Determination of whether Chlorophyll, Chlorophyll Alpha and Beta, the Petro-
leum Ether Extracts of the Yellow Pigments of Alfalfa, can be Used as a
Source of Vitamin A in Animal Nutrition ..........................................-..... 75
A Study of Some of the Constituents of Citrus Fruits, Loquats, Roselle, and Guava:
Pectin, Oils and Glucosides .............................. .....................-- ................ 75
The Determination of the Nutritional Status of Rural School Children in Five Rep-
resentative Counties in Florida ...- ... .. ............... ......- ....... ... 76
The Relation of Growth to Phosphorus, Calcium and Lipin Metabolism as Influ-
enced by the Thymus ....... ................................ .... 76
Field Studies of the Diseases Affecting the Pecan Including Control Measures....... 83
Field Studies of the Insects Attacking the Pecan Including Control Measures....... 83
Variety Response of Pecans to Different Soil Types, Localities, Etc..................... 83
Cooperative Fertilizer Tests in Pecan Orchards ..........------- ---. ..................... 83
Variety and Stock Tests of Pecan and Walnut Trees....... ...................... 85
Variety Tests of Grapes ............................... ............................... 85
Propagating, Planting and Fertilizing Tests with Tung-Oil Trees................... 85
Observation and Testing of Various Citrus Hybrids......................-........ ......... 77
Testing of Native and Introduced Shrubs and Ornamentals and Methods of Their
P ropagation .. ..... ............ ..... .................................... ..... ....... .. 81
Variety, Propagation and Planting Tests of Pear, Avocado, Japanese Persimmon,
F ig and O their F ruits ............................................. ................................. ......... 8 1




Department
HORTICULTURE
(Continued)






PLANT
PATHOLOGY


Number
59
80
81
110
111
139
164
x
x
1
3
4
11
19
24
30
32
114
115
116
118
126

127
128
130
131
132
143

144

145
146

147

148
150
151


Name of Project Page
Variety Tests of Berries (Rubus spp.) ..................................... .......-- .........---- .... 82
Cooperative Cover Crop Tests in Pecan Orchards........................................................... 82
Tests of Different Stocks as Rootstocks for Satsuma Oranges.................................. 78
Phenological Studies on Truck Crops in Florida........................................................ 87
Fundamental Physiology of Fruit Production....................................................... 78
Avocado Maturity Studies ............ .. ................................. .. .-- .........--- -- ....- 79
Rejuvenation Experiments with Neglected Pecan Orchards ...................... ..... 82
Research in Fumigation and Sterilization Methods.......................................... 86
Mulch Paper Investigations ........................ ............................ ....- ---.. 88
Gumming of Citrus ........... ........................ .... ............. ............. ..... 92
M elanose and Stem-End Rot of Citrus ......................... ......... .................................. 93
Investigation of Pecan Diseases-Pecan Scab...................................................... 105
Citrus Canker ..- --.-..........-.....- .......... ........................... .. ........--............ 94
Down M ildew of Cucurbits ................ ................................. ......................... - ----. 97
Citrus Scab and Its Control ..................................... ....... ..... ... . .... .... ... 97
Control of Downy Mildew of Cucurbits and Other Host Plants................................... 97
Citrus B light, or Chronic W ilt.......................................................... .......................... .. 95
D diseases of Citrus A phids ...... ...... ...... .... ................................................... ............. 96
Nailhead Spot of Tomatoes-Control .-........................-- .. .............. ............... 98
Nailhead Spot of Tomatoes- Cause .................. ........................... .............. 99
Corn Disease Investigations ....................... ...... ..... ...... .......... .. ... ......... 103
Investigations Relative to Certain Diseases of Strawberries of Importance to
F lorida .................................................. .................. .... ........... .................................. 100
Investigation upon the Anthracnose Disease of Strawberries......................... ....... 100
Investigation upon the French Bud, Crimps, or Briar Bud Disease of Strawberries 101
Investigations of Diseases of W white Potatoes .............................. ............................ 102
Control of Late Blight of Irish Potatoes................................ ........................................ 102
Rhizoctonosis, Scurf and Little Potato ...................................................................... ... 102
Investigation of Brown Rot of Potatoes and Related Plants Caused by Bacterium
solanacearum E F S. .............. ................... .................................................................. 103
Investigation of and Control of a Fungous Disease of Tomatoes Caused by Stem-
phylium sp. .......... ....... .......... .... ......... .... ..... ........ 99
Investigation and Control of a Disease of Corn Caused by Physoderma zeae-maydis 103
Investigation of Seedling, Stalk and Ear Rot Diseases of Corn Caused by Diplodia
spp. .......--------........................................ ... ..........-..... .......................................... 104
Investigation of Seedling, Stalk and Ear Rot Diseases of Corn Caused by Fu-
sarium spp. .......................................................... .............................................. ......... 104
Investigations of Diseases of Ferns and Ornamental Plants .................................. 105
Fusarium Wilt of Watermelons ...................-........ ..................- 106
D diseases of W aterm elons ........................................................ ..................... ................. 106










Department
CITRUS
EXPERIMENT
STATION



EVERGLADES
EXPERIMENT
STATION













TOBACCO
EXPERIMENT
STATION



SUB-TROPICAL
EXPERIMENT
STATION


Project
Number
26
34
35
83
102
x
84
85
86
87
88
89
90

124
125
168
169

170
171
25
33

117
152


Name of Project Page
Citrus Progeny and Bud Selection ................... ................. ........-............ 108
Propagation Experiments with Citrus Plants of Various Kinds ............................... 108
Testing of Introduced and New Varieties and Hybrids of Citrus and Near-Citrus 109
Cover Crops and Green Manure Studies in Citrus Groves.......................................... 109
Citrus Variety Test, Including Rootstocks .................... ............................ .... .... 109
Grove Cultivation Experiments ..... ............................................. 111
Forage, Truck and Field Crop Trials .................... .............. ......... 121
Fruit and Forest Tree Trials -............................. ........... 122
Field Fertilizer Experim ents .................................. ........ ......... ......... 122
Insect Pests and Their Control ................................. ....... ... .. ............... .... .. 124
Soil Investigations .......... .. ....................................................................................... 124
D drainage Studies .......................... .. .. ......................... .... .... ................... 128
Soils and Crop Studies, Including Rotation, Fertilizer and Cultural Practice Ex-
periments ................................................... 128
Studies Relative to Plant Pathological Problems of the Everglades............................ 128
Investigations Relative to the So-called "Yellows" of Beans....................................... 128
The Role of Special Elements in Plant Development Upon the Peat and Muck
Soils of the Everglades .............. ........ .................................................................... 129
Studies Upon the Prevalence and Control of the Sugar Cane Moth Stalk Borer
(Diatraea saccharalis) in South Florida ..................... ........................ 130
Studies Upon the Prevalence and Control of Rodents Under Field and Village
C ond ition s ................................................ ....... ........ .............. .......................... .. 130
Sugar Cane Investigations ....................................... ..... ............. .. ........... ... 130
Field and Laboratory Studies of Tobacco Diseases................................................ 133
Variety Tests of Cigar Wrapper Tobacco for Resistance to Black Shank (Phy-
tophthora nicotianae Breda de Haan.) ...................................................................... 133
Fertilizer Experiments with Shade Tobacco ......... ................ ....................... 134
Studies on the Effects of Certain Chemical Elements on the Growth and Leaf Qual-
ity of Shade-Grown Cigar Wrapper Tobacco .......................... ..-.- 135
No research work under way at close of fiscal year.
Legislative Act Authorizing this Station...................................................... 136





Annual Report, 1930 15

REPORT OF BUSINESS MANAGER

Wilmon Newell, Director,
SIR: I submit the following report of the credits received
and expenditures vouchered out of various Experiment Station
funds for the year ending June 30, 1930.
Respectfully,
K. H. GRAHAM,
Business Manager.


MAIN EXPERIMENT STATION, 1929-1930
RECEIPTS
State Appropriation % Biennium........... ........... ........$267,245.00

EXPENDITURES
Salaries ..........................................................................$109,999.99
Labor ................................................................ ........ 26,764.77
Stationery and Office Supplies .................................. 3,080.32
Scientific Supplies ...................................................... 4,914.42
Feeds ............................................................................. 5,039.48
Sundry Supplies ......................................................... 5,134.30
Fertilizers .................................................................... 4,303.65
Communication Service ............................................ 1,835.93
Travel ............................................................................ 11,982.03
Transportation of Things ........................................ 1,564.91
Publications .................................................................. 5,256.39
Heat, Light, Power ................................................... 3,883.02
Furniture and Fixtures ..................................... ... 4,602.97
Library .......................................................................... 3,360.52
Scientific Equipment ................................................. 7,830.18
Livestock ...................................................................... 617.77
Tools, Machinery ........................................................ 3,857.20
Buildings and Land ................................................... 10,306.09
Contingent .................................................................... 895.56
Balance ............ .......................................... ................ 52,015.50

$267,245.00





16 Florida Agricultural Experiment Station

STATION INCIDENTAL FUND, 1929-1930

RECEIPTS
Balance on hand July 1, 1929....................................$ 4,722.59
Receipts, 1929-1930 .................................................. 22,507.93

$ 27,230.52
EXPENDITURES
Salaries .......................................................................... 4,272.73
Labor ...................................... ................................... 2,688.57
Stationery and Office Supplies ................................ 464.03
Scientific Supplies ..................................................... 272.86
Feeds ...................................... 4,321.93
Sundry Supplies .......................................................... 1,521.31
Fertilizers ........................... ---.............................. 441.40
Communication Service ............................................ 86.97
Travel .......................................................................... 439.80
Transportation of Things ......................................... 547.76
Publications ................................................................. 91.70
Heat, Light, Power ................................................... 1,035.07
Furniture and Fixtures .............................................. 303.95
Library .......................................................................... 108.67
Scientific Equipment ................................................. 1,567.34
Livestock ..................--- ................................... ........ 1,060.72
Tools, Machinery ........................................................ 738.69
Buildings, Land ........................................................... 1,072.26
Contingent ................................................................... 537.77
Balance .................................................................. 5,656.99

$ 27,230.52

CITRUS EXPERIMENT STATION, 1929-1930
RECEIPTS
State Appropriation % Biennium .............................................. $ 15,950.00

EXPENDITURES
Salaries ............................................................... ......$ 5,457.77
Labor ................................................... ....................... 2,822.16
Stationery and Office Supplies .................................. 30.62
Scientific Supplies ................................................. 220.65
Feeds .............................................................................. 442.72
Sundry Supplies .......................................................... 411.89
Fertilizers .................................................................... 1,077.11
Communication Service .............................................. 93.55
Travel ........................................................................ 255.40
Transportation of Things ........................................ 55.58
Publications ............................................................. .00
Heat, Light, Power .................................................... 600.44
Furniture and Fixtures ............................................. 60.00
Library ......................................................................... 27.13
Scientific Equipment .................................................. 306.37
Livestock ...................................................................... 265.00
Tools, Machinery ........................................................ 477.01
Buildings, Land ......................................................... 2,980.37
Contingent .................................................................... 190.73
Balance .......................................................................... 175.50

$ 15,950.00






Annual Report, 1930 17

EVERGLADES EXPERIMENT STATION, 1929-1930
RECEIPTS
State Appropriation 1/ Biennium ............... ....... ......................... 68,100.00

EXPENDITURES
Salaries ..................................... ........................ ......$ 14,014.90
Labor ........................................................................... 14,925.32
Stationery and Office Supplies ............................ .. 428.45
Scientific Supplies ...................................................... 1,693.18
Feeds ............................................................................. 114.70
Sundry Supplies .. ..................................................... 2,511.05
Fertilizers .........................................................702.84
Communication Service ........................................... 237.75
Travel ........................... ................................................ 1,341.02
Transportation of Things -----................................. ... 489.40
Publications ............................................................ .00
Heat, Light, Power ........ ...................................... 2,391.30
Furniture and Fixtures ...............................---- 844.40
Library ......................................................................... 518.67
Scientific Equipment .......................................... 354.72
Livestock .. ............................................................. .00
Tools, Machinery .................................................... 3,943.51
Buildings, Land .............................................. 19,107.46
Contingent ............................................................550.55
Balance .......................................................... ..... 3,930.78
$ 68,100.00

TOBACCO EXPERIMENT STATION, 1929-1930
RECEIPTS
State Appropriation 1/ Biennium .......................... .....................$ 25,600.00

EXPENDITURES
Salaries ................................................. .................. $... 5,650.00
Labor ........................................................................... 3,635.91
Stationery and Office Supplies ................................ 25.72
Scientific Supplies ...................................................... 303.25
Feeds ....................................................................... 121.32
Sundry Supplies ............ ...................................... 421.96
Fertilizers ................................................................... 496.99
Communication Service ....---.................................-- 69.07
Travel ............................................................................ 660.86
Transportation of Things ........................................ 156.41
Publications .............................................................. ..00
Heat, Light, Power .......................- .......................... 279.97
Furniture, Fixtures .................................................... 529.75
Library ......................................................................... 71.31
Scientific Equipment ................................................. 257.80
Livestock ........................................................................ .00
Tools, Machinery ....................................................... 203.58
Buildings, Land ................... ..................................... 10,280.56
Contingent .................................................................... 18.40
Balance .......................................................................... 2,417.14
$ 25,600.00





18 Florida Agricultural Experiment Station

SUB-TROPICAL EXPERIMENT STATION, 1929-1930

RECEIPTS
State Appropriation % Biennium ................................................ $ 15,000.00
*.
EXPENDITURES
Salaries ............................. .................................$ 1,050.00
Labor ................................................................ 1,041.37
Stationery and Office Supplies ................................ .00
Scientific Supplies ................................................ 472.50
Feeds .......................................................................... .00
Sundry Supplies ....................................................... 91.06
Fertilizers .................................................................... .00
Communication Service ...................................... .00
Travel ............................................................................ 37.91
Transportation of Things ........................................ .00
Publications ............... ............ .. .00
Heat, Light, Power .................................................... 32.51
Furniture and Fixtures ............................................ 371.01
Library .......................................................................... .00
Scientific Equipment ................................................. 1,400.45
Livestock ..................................................................... .00
Tools, Machinery .................................................... .00
Buildings, Land .......................................................... 3,552.29
Contingent .................................................................... 107.00
Balance .......................................................................... 6,843.90

$ 15,000.00

WATERMELON DISEASE INVESTIGATIONS, 1929-1930

RECEIPTS
State Appropriation First Year of Biennium ................................$ 15,000.00

EXPENDITURES
Salaries ....... .... ............................. ..........$ 2,633.34
Labor ........................................................................ 829.82
Stationery and Office Supplies ................................ 9.00
Scientific Supplies ..................................................... 170.52
Feeds .............................................................................. 1.45
Sundry Supplies .................................................... 96.6f7
Fertilizers .................................................................... 204.75
Communication Service .............................................. 13.67
Travel .............. ................................................... .... 383.41
Transportation of Things ........................................ 59.80
Publications ................. ....................................... .00
Heat, Light, Power .................................................... 89.28
Furniture, Fixtures .................................................... 1,445.58
Library .......................................................................... 31.93
Scientific Equipment ............ ................................... 872.14
Livestock .................................................................. .00
Tools, Machinery ....................................................... 239.74
Buildings, Land ........................................................... 6,746.36
Contingent ................................................................... .00
Balance ......................................................................... 1,172.54

$ 15,000.00






Annual Report, 1930


PUBLICATIONS
Wilmon NeweU, Director.
SIR: I submit the following report of the Editorial and Mail-
ing Department for the fiscal year ending June 30, 1930.
Respectfully,
J. FRANCIS COOPER,
Editor.


The Editors devote approximately one-half of their time to
Extension work, leaving only one-half for Experiment Station
work.
BULLETIN EDITING

The Experiment Station has now published a total of 217 bul-
letins. The last 11 of these, published during the past fiscal
year, amount to 448 pages of printed matter. This is the great-
est number of different bulletins ever printed by the Station in
one year, although the total number of pages was slightly below
that of last year. Ninety thousand copies of these 11 bulletins
were printed. Editing the copy and reading the proof of these
bulletins was done by the Editors.
Following is a list of the bulletins issued during the year, with
titles, pages, and number of copies of each:
Bul. Title Pages Edition
207 Angular Leaf Spot and Fruit Rot of Cucumbers.... 32 4,000
208 Cucumber Diseases in Florida...............--..--... 48 12,000
209 Lawns in Florida.............................- ...----- ------ 20 20,000
210 Corn Diseases in Florida................................. 36 12,000
211 A Study of the Root Systems of Some Important
Sod-Forming Grasses........................ ........ 28 4,500
212 Diseases of Sweet Potatoes in Florida.................... 40 9,000
213 Potash in Relation to Cotton Wilt............................ 12 3,000
214 Cotton Diseases in Florida.......................................... 32 6,000
215 Effects of Irrigation with Sewage Effluent on the
Yields and Establishment of Napier Grass and
Japanese Cane .............. .............. . ... 20 4,000
216 A Nutritional Study of the White School Children
in Five Representative Counties of Florida............ 52 7,500
217 A Study of the Cost of Transportation of Florida
Citrus Fruits with Comparative Costs from Other
Producing Areas................................... 128 5,000

SUMMARY OF BULLETINS
A brief summary of the principal points covered in the bul-
letins follows:
207. Angular Leaf Spot and Fruit Rot of Cucumbers. (Geo.
F. Weber, pp. 32, Figs. 16.) Cites evidence to show that fruit





Florida Agricultural Experiment Station


rot is caused by the same organism that causes angular leaf spot
of cucumbers. All varieties of cucumbers tested showed 100
percent susceptibility to the disease. Tells of economic im-
portance, symptoms, the organism, seasonal development, dissem-
ination, relation of parasite to host, control, etc.
208. Cucumber Diseases in Florida. (Geo. F. Weber, pp. 48,
Figs. 37.) Gives the symptoms of the common cucumber dis-
eases, with methods of their control.
209. Lawns in Florida. (C. R. Enlow and W. E. Stokes, pp.
20, Figs. 11.) Describes the grasses suitable for lawns, methods
of preparing the land, sowing the seed, renewing old lawns, care
of the lawn, and winter grasses.
210. Corn Diseases in Florida. (A. H. Eddins, pp. 36, Figs.
25.) Gives the symptoms and control measures for the various
rots attacking corn in Florida.
211. A Study of the Root Systems of Some Important Sod-
Forming Grasses. (A. S. Laird, pp. 28, Figs. 6.) Describes the
method of growing the grasses, examining the root systems, and
relates results of a comparative study of different grasses grown
under pasture, under lawn, and under putting green conditions.
Describes the influence of mowing and of clay top-dressings on
sod formation in sandy soils.
212. Diseases of Sweet Potatoes in Florida. (Geo. F. Weber
and Erdman West, pp. 40, Figs. 24.) Gives the symptoms and
control measures for various rots attacking sweet potatoes in
Florida.
213. Potash in Relation to Cotton Wilt. (M. N. Walker, pp.
12, Figs. 0.) Relates the results of experiments in which it was
shown that potash did not retard the development of wilt in
cotton.
214. Cotton Diseases in Florida. (M. N. Walker, pp. 32, Figs.
15.) Gives the symptoms and control measures for common
cotton diseases, together with directions for delinting cotton
seed.
215. Effects of Irrigation with Sewage Effluent on the Yields
and Establishment of Napier Grass and Japanese Cane. (W. E.
Stokes, W. A. Leukel, and R. M. Barnette, pp. 20, Figs. 0.) De-
scribes an experiment and relates results where the two crops
were irrigated with sewage effluent, with city water, and were
not irrigated.
216. A Nutritional Study of the White School Children in
Five Representative Counties of Florida. (Chester F. Ahmann,





Annual Report, 1930


Ouida Davis Abbott, and Georgia Westover, pp. 52, Figs. 11.)
Tells of the results of a nutritional survey, with most common
defects found in the children, and their relation to diet and to
each other.
217. A Study of the Cost of Transportation of Florida Citrus
Fruits with Comparative Costs from Other Producing Areas.
(Marvin A. Brooker, pp. 128, Figs. 28.) Describes the rate
structures applying to Florida citrus fruits and to citrus fruits
from California and from various foreign countries.

PRESS BULLETINS ISSUED
Thirteen new press bulletins were issued and 16 old ones
were reprinted during the year. From 2,000 to 3,000 copies of
each were run at a printing. The list follows:

No. Title Author
415 Plants Susceptible and Resistant to Root-Knot................J. R. Watson
416 The Control of Root-Knot in Seedbeds.............................J. R. Watson
417 Foot-Rot of Citrus Trees and Its Treatment............Arthur S. Rhoads
418 Gummosis and Psorosis of Citrus Trees. .................Arthur S. Rhoads
419 Treatment of Gummosis and Psorosis of Citrus
Trees ............................................................. ................... A rthur S. Rhoads
420 Disinfectant Pastes and Washes for Treating
Bark Diseases of Citrus Trees...................................Arthur S. Rhoads
421 The Cause and Control of Melanose........................Arthur S. Rhoads
422 The Cause and Control of Citrus Scab..................Arthur S. Rhoads
423 Soil Sterilization........................... ....... Geo. F. W eber
424 Dry Rot of Lumber in Storage and in Buildings............Geo. F. Weber
425 Mushrooms and Their Culture........................ .......Geo. F. Weber
426 Black Spot, Powdery Mildew, and Brown Canker
of Roses .-.................. ............... W mi. B. Shippy
Bulletin List.
324 Gassing the Corn Weevil (Reprint)......................... J. R. Watson
348 Growing Sweet Peas in Florida (Reprint).......................W. L. Floyd
370 Moles (Reprint) ............. ........... ..... J. R. W atson
372 Mole-Crickets (Reprint).................................. J. R. W atson
386 Papaya Culture (Reprint).......................... .... Harold Mowry
391 Salamanders and Gophers (Reprint).............................. R. Watson
392 Control of Mealy Bugs (Reprint)............------...-- J. R. Watson
397 Asparagus as a Truck Crop in Florida (Reprint)............M. R. Ensign
398 Crotalaria as a Soil Builder (Reprint)..W. E. Stokes and W. A. Leukel
402 Gas the Ants (Reprint).............................. J. R. Watson
403 Purple Scale (Reprint) ..------.. .......--------.J. R. Watson
404 Coccidiosis of Chickens (Reprint)........................................A. L. Shealy
407 Blackhead of Turkeys (Reprint)... .. ...................... E. F. Thomas
408 Internal Parasites of Poultry (Reprint)........................D. A. Sanders
409 The Chinch Bug on St. Augustine Grass Lawns
(Reprint)............................... .... J. R. W atson and H. E. Bratley

DISTRIBUTION OF BULLETINS
The distribution of bulletins and supplies is handled in the
mailing room which is a part of this department. During the
year more than 54,000 Experiment Station bulletins left the mail-





Florida Agricultural Experiment Station


ing room, approximately 15,000 of them for libraries, and the
remainder for Florida farm homes. Thousands of press bulletins
were sent out to papers and to individuals. Except for libraries
and technical workers, the bulletins are sent only on special re-
quest, and not to a general mailing list.

NEWS STORIES
In addition to bulletins, news stories help take the results of
the station's investigations and its messages of better farming
to the people of Florida. The Agricultural News Service, pub-
lished weekly by the Agricultural Extension Service, each week
carries from three to six stories about Experiment Station work
or advice from the station's workers. This is reprinted largely
in the newspapers and somewhat in the farm papers of Florida.
Information about the station and its work is disseminated
through special stories to news and farm papers, and by the
Associated Press. During the year 58 stories relating to the
Experiment Station were sent to the Associated Press, and dis-
tributed by it to 45 member papers in Florida. One special story
relating to work of the station was sent to a paper in Georgia,
on request, and another was sent to a daily paper in Florida. Still
another was sent to the farm and grove section of 50 Florida
newspapers.
The Editor conducted a farm page in one Florida daily. The
farm page was carried in each Sunday edition throughout the
year. He contributed to a similar page in another daily. Ques-
tions and answers on farming subjects, based on questions ac-
tually received and answered by Station workers, were largely
used in both pages.
Eight special stories relating to the station and its work were
supplied to and used by one Florida, one Southern, and two na-
tional farm papers. The publisher of another Southern farm
paper was assisted in obtaining stories about the Main Station
and the Citrus Station in his visit to Florida.

RADIO
Thirty-minute radio programs were put on the air over WRUF
each week day during the year. These programs covered all
phases of farm operations. The arrangement of the programs
was noticeably improved during the year, and comment indicates






Annual Report, 1930


that the Florida programs equal or exceed in excellence those
of other states.
Experiment Station workers delivered 80 talks during the year,
of which four were prepared and delivered by the Editor him-
self. The Assistant Editor arranged the programs, edited the
papers, supervised the broadcasting, and read many of the papers
and miscellaneous items. Questions and answers were featured
on many of the programs.

ARTICLES CONTRIBUTED TO SCIENTIFIC AND
OTHER PUBLICATIONS

The following articles were contributed by members of the
Experiment Station staff to various technical and popular pub-
lications during the year. In addition, many copies of talks
made by staff members and of short, popular articles written by
them were published during the year in Florida farm papers.

"A Suggested Simplification of the Present System of Official Testing With
the Dairy Breeds of Cattle". R. B. Becker and P. C. McGilliard.
Journal of Dairy Science, Vol. 12, pages 337-350, July, 1929.
"An Outbreak of the Corn Syrphus Fly". J. R. Watson.
Proceedings of Florida Horticultural Society, 1930.
"Composition and Nitrification Studies with Crotalaria Striata". W. A.
Leukel, R. M. Barnette, J. B. Hester.
Soil Science, Vol. XXVIII, pages 341-371, November, 1929.
"Development of Plant Pathology in the Florida Experiment Station".
G. F. Weber.
Florida College Farmer, Vol. I, pages 4-5, 1930.
"Diluted Calcium Arsenate for Boll Weevil Control". E. F. Grossman.
Journal of Economic Entomology, Vol. 22, No. 4, pages 662-665.
"Disease and Climate as Pertaining to the Florida and Maine Potato Sec-
tions". L. 0. Gratz.
Phytopathology, Vol. 20, pages 267-288, 1930.
"Dry Rot of Corn Caused by Diplodia macrospora Earle". A. H. Eddins.
Phytopathology, Vol. 20, pages 439-448, 1930.
"Effect of Burning upon the Accumulation of Organic Matter in Forest
Soils". R. M. Barnette.
Soil Science, Vol. 29, pages 281-284, April, 1930.
"Effect of Irrigation with Sewage Effluent on the Yields and Establish-
ment of Napier Grass and Japanese Cane". W. E. Stokes, W. A. Leu-
kel, R. M. Barnette.
Journal of American Society of Agronomy, Vol. 22, pages 540-548,
1930.
"Effect of Seed-Potato Treatment on Yield and Rhizoctonosis in North-
eastern Maine from 1925 to 1928". E. S. Schultz, L. O. Gratz and
Reiner Bonde.
Phytopathology, Vol. 20, pages 47-64, 1930.
"Gray Spot of Tomato Leaves Caused by Stemphylium Solani n. sp." G. F.
Weber.
SPhytopathology, Vol. 20, pages 513-518, 1930.






Florida Agricultural Experiment Station


"Gummosis and Psorosis of Citrus Trees, with Special Reference to Their
Cause and Control." A. S. Rhoads.
Citrus Industry, Vol. 10, No. 8, pages 3-7, 1929.
"Increasing the Protein Content of Pasture Grasses by Frequent Light
Applications of Nitrogen". C. R. Enlow, J. M. Coleman.
Journal American Society of Agronomy, Vol. 21, pages 845-853,
1929.
"Life and Work of the Late Professor A. C. Baer." R. B. Becker.
Association of Southern Agricultural Workers Proceedings, 1930.
"New Aphicides." A. N. Tissot, W. L. Thompson.
Florida Entomologist, Vol. XIV, No. 1, March, 1930.
"Notes on Rubber Tree Caterpillars." H. E. Bratley.
Florida Entomologist, Vol. XIII, No. 3, September, 1929.
"Pumpkin Bugs and Crotalaria." J. R. Watson.
Proceedings Florida Horticultural Society, 1930.
"Raising Trees that Have Been Set too Deep." A. S. Rhoads.
American Fruit Growers Magazine, Vol. 50, No. 2, page 27, 1930.
"Some New or Little Known Citrus Diseases Observed During the Past
Year." A. S. Rhoads.
Citrus Industry, Vol. 11, No. 5, pages 3-7, 1930.
"The Value of Grazing for Fattening Cattle in Beef Production". A. L.
Shealy.
Association of Southern Agricultural Workers Proceedings, 1930.
"The Winter Cleanup as a Control for Citrus Aphis." W. L. Thompson.
Proceedings Florida Horticultural Society, 1930.
"Water Injury to Citrus Trees in Florida." A. S. Rhoads.
Empire Forester (N. Y. State College of Forestry Annual), Vol.
16, pages 24-31, 1930.






Annual Report, 1930


REPORT OF THE LIBRARIAN
Wilmon Newell, Director.
SIR: I submit the following report of the Library for the fiscal
year ending June 30, 1930.
Respectfully,
IDA KEELING CRESAP,
Librarian.


The work of the Library has progressed satisfactorily during
the past fiscal year. Routine work has been the heaviest of any
year in its history. It is estimated that the number of people
using the Library has been trebled.
The most important piece of new work undertaken for the
year was the systematizing of the relation between the Library
and the four branch stations and eight field laboratories. The
librarian has always attempted to serve these groups, as well
as the main Station, and now a definite system has been inaug-
urated, by which the workers located at these places may have
adequate library service. Every month in addition to the many
requests for books, information, bibliographies, etc., 70 scien-
tific periodicals are circulated to the distant workers. This list
will increase from month to month. In March a mimeographed
"List of Current Periodicals" was issued by the librarian and
distributed. Twice a year a supplement to this "List" will be
issued, which will keep the entire staff informed as to the new
periodicals added to the Library's collection. The absent mem-
bers will be lent as many of the periodicals each month as they
wish to review. By thus circulating these periodicals it gives
to the staffs of the branch stations and field laboratories the op-
portunity of keeping up with current scientific research, thus
saving a large sum of money that would otherwise have to be
spent in individual station subscriptions.
The Library was made a gift of 18 excellent volumes on "Fun-
gi" by Mr. M. B. Punnett of Daytona Beach.
At the expense of needed floor space, one book stack has been
added. This gives the maximum amount of shelf space that can
possibly be had in the Library's present quarters.
Cataloging has been interfered with by the multiplicity of
other duties. This is regretted, as no phase of the work is more
important. But the increase in correspondence, the work re-






26 Florida Agricultural Experiment Station

quired to circulate material, the additional shelf work, the need
for constant attendance at the charging desk, have all combined
to retard cataloging.
Books and articles, needed by the staff, faculty, and graduate
students, when not available here, have been borrowed from
other institutions.
During the year 457 volumes have been prepared and sent to
the bindery. A total of 702 volumes has been added, bringing
the number of accessioned volumes in the Library to 7,010.
The librarian has continued her study of the literature of
tropical agriculture. She has no published articles to report,
as all available time for research has been spent in compiling
data for the history of agriculture of Florida, which she plans to
write.






Annual Report, 1930


AGRICULTURAL ECONOMICS
Wilmon Newell, Director.
SIR: I submit the following report of the Department of Agri-
cultural Economics for the fiscal year ending June 30, 1930.
Respectfully,
C. V. NOBLE,
Agricultural Economist.


AGRICULTURAL SURVEY OF SOME 500 FARMS IN THE
GENERAL FARMING REGION OF NORTHWEST FLORIDA
(Purnell Project No. 73)
As stated in the 1929 report, a re-survey was made in the
summer of 1929 of 110 of the same farms which were covered
in the original survey. All data were for the year 1928 and all
farms re-surveyed had white operators. The re-survey has
been tabulated and summarized and the following table gives
a brief comparison of these same 110 farms for the years 1925
and 1928.
Average per farm
1925 1928
Total acres operated ........................ 156 155
Total crop acres ............................... 72 74
Total capital ...................................... $7,225 $6,945
Total farm receipts ........................ $2,121 $1,384
Total farm expenses, except labor of
operator and interest on capital in-
vested ................ ..... ............... 1,384 1,167
Farm income e .............................................. 737 217
Interest on capital invested at 7%........ 506 486
Labor income of operator..................... $ 231 $-269

It will be noted that the financial returns in 1928 were much
lower than in 1925. The principal cash crops in this area are
cotton, Spanish peanuts, watermelons, and cane syrup. In 1925
the cotton yield was high for this section and the price was
good-an unusual combination; in 1928 the exact opposite was
true. Watermelons and cane syrup were also much lower in price
in 1928 than in 1925. In 1925, the average labor income of the
110 farm operators was $231. In 1928, there was no return to
the operators for their year's labor, and the farms lacked $269
of paying 7 percent interest on their investments. In other
words, there was a return of approximately 3 percent on the






Florida Agricultural Experiment Station


capital invested, making no allowance for the operator's labor.
There was a return from the farm, however, that was not in-
cluded in the labor income figure, represented by the value of
pork, corn for grits, milk, butter, poultry, eggs, vegetables and
other farm products furnished the operator and his family, and
the use of the house as a home. In 1925 these non-cash returns
amounted to $624 and in 1928 to $551 per farm.

A STUDY OF THE COST OF TRANSPORTATION OF FLOR-
IDA CITRUS FRUITS WITH COMPARATIVE COSTS FROM
OTHER STATES AND FOREIGN COUNTRIES
(Purnell Project No. 103)
This project has been completed and is now in the hands of
the printers. It will be published as bulletin 217 of this Station
and should be available soon for distribution.
During the year the manuscript was revised and prepared for
publication. The writer was in attendance at Cornell University
and received advice and suggestions from members of the depart-
ment of Agricultural Economics and Farm Management at that
place.

AN ECONOMIC STUDY OF DAIRY FARMING IN FLORIDA
(Purnell Project No. 104)
Records have been re-checked and major tabulations com-
pleted. The tabulations reported a year ago, have been cor-
rected where errors were found.
The following tables have been prepared for each of the six
areas:
Uses of land; distribution of crops; crop yields; farm capital;
farm receipts; miscellaneous receipts; farm expenses; summary
of the farm business; summary of milk costs, being revised for
all areas; costs of raising heifers; animal units; summary of live-
stock other than dairy cattle; appreciation and depreciation of
cattle; number of months of labor and wages per month; amount
and value of all feeds and to what fed; grain purchased and home
grown and to what fed; hay purchased and home grown and
to what fed; silage and soiling crops and to what fed; beet pulp,
apple pulp, bulky lass and cottonseed hulls, and to what fed.
Some of the relationships which are being analyzed at pres-
ent are:






Annual Report, 1930


Number of cows per dairy to cost of milk, labor income and other fac-
tors.
Milk production per cow to cost of milk, labor income and other factors.
Value of cows to cost of milk, labor income and other factors.
Quantity of beet pulp used per cow to cost of milk, labor income and
other factors.
Silage and soiling crops to milk production and other factors.
Improved pasture to milk production, cost of milk, and labor income.
Up to the present time the factor which seems to have the
greatest influence on the returns to the dairy farmer is milk
production per cow. The principal causes for high milk pro-
duction are an animal of high productive capacity to begin with,
a wise feeding practice, and good care. It is believed that suf-
ficient reliable data are available to analyze the influence of these
important factors upon production.

COTTON GRADE AND STAPLE ESTIMATES AND PRIMARY
MARKET PRICE STUDY
(Purnell Project No. 121)

(This project was in cooperation with the comprehensive study
being made of the cotton area by the Bureau of Agricultural
Economics, U.S.D.A.) The summarization of all Florida data
was completed and forwarded to the Bureau. An independent in-
terpretation of the Florida data was made and constituted the
thesis of the leader of this project for his Master of Science de-
gree, received in May, 1930. The following summary covers the
principal findings:
SUMMARY

1. The study represents 1,709 bales of cotton which were
ginned at three Florida gins during the period August 23 to
November 30, 1928. Samples were taken from each bale at the
time of ginning and these were classed by government classes.
2. Approximately 67 percent of the cotton was classed by
government classes as white, and 33 percent as spotted. Most
of the spotted cotton was from one area.
3. The white cotton classed 21 percent above middling, 46
percent middling and 33 percent below middling. The spotted
cotton consisted of 40 percent above middling, 45 percent mid-
dling and 15 percent below middling.
4. There was 19 percent untenderable cotton in the samples
taken. The untenderable cotton was due to the following causes:






Florida Agricultural Experiment Station


241 bales to staple, 70 bales to grade, and 18 bales to both grade
and staple.
5. The amount of spotted cotton increased as the ginning sea-
son advanced. For white cotton, the percentage that graded
below middling increased each month except November, of which
data were for only one area.
6. There seemed to be a tendency on the part of the local
buyer to recognize grades in grading the cotton, but not a uni-
form or consistent one. Based on the government's classifica-
tions, the nearer the cotton approached middling the greater
degree of similarity in grading, while for the better grades the
greater was the tendency for the buyer to grade low, and the
poorer the grade the greater his tendency to grade high.
7. The average value in the central markets, based on the gov-
ernment's classification of 1,569 bales, was $1.89 per bale less
than basis, white middling 7/8 inch staple.
The local buyers paid $1.26 less per bale on the average for
all cotton than for base grade and staple.
8. The average spread for white cotton was $3.80 per bale,
but for area one the spread was $3.00, area two $3.57, and area
three $8.14. For spotted cotton the average spread was $2.58
per bale for area one and $7.60 for area three, with an average
of $6.33 per bale for both areas. The average spread for the
1,569 bales of cotton sampled was $4.51 per bale, which included
both white and spotted cotton.
9. There was a decided tendency for the spread to widen as
the quality of grade and staple increased.
10. Growers were paid only a part of the premiums called for
by better grades and staples, and the poorer grades and staples
were penalized only a part of the discount quoted by the central
markets. The local buyers on the average tended to go about
33 percent of the distance toward buying on the basis of quality.

A STUDY OF FLORIDA TRUCK CROP COMPETITION
(Purnell Project No. 123)
This study has been divided into two parts. The first part,
covering the weekly car-lot competition of each of Florida's im-
portant truck crops with other states and foreign countries for
the five-season-period ending 1928-1929, has been completely
tabulated and charted. Interpretation of these data is in pro-
gress at present.






Annual Report, 1930


The second part concerns itself with the sectional competition
within the state of Florida for the important truck crops. Car-lot
data for this study were obtained directly from the railroad
companies serving this state. The data are by shipping point
and by weeks, covering the shipping season 1928-1929. After
completing the compilation of car-lot shipments it was found
necessary to obtain the express and boat movement, since less
than car-lot movement is very important with some types of
truck crops. This work has also been completed and compiled
on the same basis as the car-lot movement for the 1928-1929 sea-
son. It was found that the express and boat movement repre-
sented the following percentages of the total movement for the
truck crops named:
Percent
String beans ...................................... ..... ...... .... 41
Eggplants ... ............... ....................... 39.3
Peppers ....................................................................... 29.9
Strawberries ..... ..................... .............. 24.8
Tom atoes ............................... ..... ............................ 13.2
Important truck crops which moved by car-lot freight almost
exclusively were:
Percent
W atermelons ........................................... ....... 100
Celery ................................. .. ...... .......... 99.8
Lettuce ............................ ..... ... ............... ....... 96.7
Cabbage ............ ..... ................ ............ ..... 95.6
Cucum bers .............................. ..... ..... ....... 93.5
White Potatoes ....................... ...... ....- ........... 93.2
Work is now in progress of sectioning the state to bring out
the seasonal competition between sections for each important
truck crop.

ECONOMIC STUDY OF THE PECAN INDUSTRY
IN FLORIDA
(Purnell Project No. 134)

(This project was in cooperation with the Bureau of Agricul-
tural Economics, U.S.D.A., and the Department of Agricultural
Economics, Teaching Division, University of Florida. It was
an emergency project due to the fact that the Teaching Division,
which was to handle all cooperative work on this project for
Florida, had its State funds materially reduced and found itself
unable to finance the field work.) Project completed.






Florida Agricultural Experiment Station


FARMERS' COOPERATIVE ASSOCIATIONS IN FLORIDA
(Purnell Project No. 154)
Two forms have been prepared; the one for use in collecting
the data and the other, a work sheet, for use in the office.
The charters of all former cooperative associations that have
incorporated either under the Florida Cooperative Marketing
Act or the general Corporation Act have been examined at the
office of the Secretary of State. Data were obtained from the
charters as to the place of business, type of business, provisions
for officers and directors, qualifications for membership, method
of voting, and whether capital stock or non-capital stock. Visits
have been made to 45 farmers' cooperative associations and
where available the following data were secured covering the
past four years and the first year of operation. Administrative
set-up; number of patrons; kind and number of contracts in
force; credit policies and loans to members; pooling practices;
advertising practices; volume of business; balance sheet and op-
erating statement. Present and past difficulties and method of
sale are being ascertained where practicable.
In addition to the 45 cooperative associations on which all data
have been obtained, a part of the data has been acquired on 25
other cooperative associations.






Annual Report, 1930


AGRONOMY
Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Agronomy for the fiscal year ending June 30, 1930.
Respectfully,
W. E. STOKES,
Agronomist.

During the year, agronomy experimental work was expanded
somewhat, due to a legislative appropriation for cooperative
agronomy experimental work. This work embraces crop variety,
fertilizer, rotation and soil fertility cooperative experiments on
the various soil types of the general farming area of the state
and is conducted cooperatively with the farmers on their farms.
The Forage Crop Office of the U. S Department of Agricul-
ture, with whom we cooperate, slightly increased funds, par-
ticularly for Crotalara investigations.
The J. C. Penney-Gwinn Corporation has leased to the State
Board of Education 560 acres of cut-over flatwoods land for
pasture experimental work. In May of 1930 preliminary work
was started. The experimental work with pastures will con-
sist of comparisons of burned and unburned native range pas-
ture plants for cattle grazing versus improved pastures, and a
comparison of various methods of establishing improved pas-
tures. Reforestation is to be studied, also, the State Forest
Service having charge of this phase of the work. The Animal
Husbandry Department of the Experiment Station is cooperat-
ing, and has charge of the beef cattle on the test.
About 10,000 pounds of Crotalaria spectabilis seed were saved
and sold at cost to interested farmers for trial plantings well
distributed over the state. This will aid us in obtaining quickly
an idea of the value of this crop for soil improvement purposes.
The seed were distributed through the Agricultural Extension
Service.
PASTURE EXPERIMENTS
(Hatch Project No. 27)
This project is divided into the following phases: pasture
grass competition tests in which 11 different pasture grasses
are grown in competition; the influence of fertilizers on the yield
and composition of pasture grasses; the influence of frequency






Florida Agricultural Experiment Station


of mowing or grazing of pasture grasses on yield and compo-
sition and the carrying capacity and forage value of various pas-
ture grasses in pure stand and in mixture. The latter phase
is in cooperation with the Animal Husbandry Department.
In the competition test on a Fellowship soil, Centipede grass
has successfully competed with and is crowding out such grasses
as Bermuda, Bahia, St. Augustine, carpet, Blue Couch, Dallis,
and all other grasses in the test. Fertilizer has materially in-
creased the yield and influenced the composition of pasture
grasses. About as good increases have been obtained with ni-
trogen alone as with a complete fertilizer. Nitrogen seems to
increase the protein content of the grass.
Frequent mowing over less frequent mowing gives about as
satisfactory a yield and a higher protein content.
In the carrying capacity and forage value test carpet, Ber-
muda, Bahia, Centipede, and a mixture of carpet, Bermuda, and
Bahia are under comparison.
All pastures have carried slightly over one beef animal per
acre with the mixed pasture giving the highest live weight gain
per acre. The average for all pastures was 257 pounds live
weight gain per acre from the middle of March to the middle
of November with no supplemental feeding.

FERTILIZATION OF PASTURE GRASSES
(Hatch Project No. 120)
The effect of fertilization and irrigation on the growth be-
havior and composition of pasture grasses mentioned in the last
annual report was studied during the growing season of 1929.
A series of separate plats of Bahia grass were treated with
nitrate of soda and water, nitrate of soda, water, and no
treatment. All plats were cut frequently during the growing sea-
son. Another series of separate plats were treated likewise but
were permitted to grow to maturity. A third series of separate
plats of Carpet and Centipede grasses were treated with nitrate
of soda and water, water, and no treatment. These grasses were
mowed frequently during the growing season. The amount of
top growth produced from plants cut frequently varied in
the order of the treatment given, i.e., nitrate of soda and water,
nitrate of soda, water, and no treatment. The percentage and
quantity of nitrogen in the cuttings from these grasses varied in
the same order as that for top growth production.






Annual Report, 1930


Plants grown to maturity and given the above treatments
showed similar relations to each other in regard to production
of top growth and percentage of nitrogen in such top growth.
The variations in the percentage of nitrogen in the cuttings from
the frequently cut plats during the season were not very marked
and such cuttings were more vegetative than the top growth
from plants not cut. The tops of the latter plants were high in
nitrogen in the early vegetative growth stages but such nitrogen
percentage gradually decreased as the plants approached ma-
turity. Plants fertilized and not cut increased in top growth
production over those not fertilized, and produced more seed, at
an earlier period, i.e., their growth was hastened through fertili-
zation.
In percentage of ash, the top growth from the frequently cut
plants was highest from plants fertilized with nitrate of soda
and watered and such percentage decreased in the order of treat-
ments given, i.e., nitrate of soda and water; nitrate of soda;
water; no treatment.
The top growths of plants grown to maturity were lower in
percentage of ash than those from plants cut frequently. The
former showed a high percentage of ash in their top growth in
the early growth stages, but such percentage decreased as they
approached maturity. In percentage of ash at the mature growth
stage the tops of the plants increased slightly in the order of
treatments given, i.e., lowest when treated with nitrate of soda
and water and highest where no treatment was given.
From the above studies thus far, it appears that grasses cut
frequently remain more vegetative and are higher in percentage
of nitrogen and ash. Since higher nitrogen indicates high pro-
tein and likewise, higher ash signifies greater mineral content,
such grasses should be superior for feeding purposes. Further
results will be given as this work progresses.
Nitrate Accumulations in Pasture Grasses:-A preliminary
study was made of the accumulation of nitrate nitrogen in Bahia
and Sudan grasses. The different forms of nitrogen from these
grasses fertilized with nitrate of soda and watered were com-
pared with similar grasses not fertilized. In no instance thus
far was a striking difference noted between the percentage of
nitrate nitrogen in grasses fertilized with nitrate of soda and
those not so treated. Further studies are underway with plants
grown under more controlled conditions as to soil moisture,
etc.






Florida Agricultural Experiment Station


LYSIMETER STUDIES ON PASTURE GRASSES
(Hatch Project No. 158)

As previously reported, four iysimeters were planted to Bahia
grass and given similar fertilizer applications. The grass in one
lysimeter was cut at very frequent intervals while that in an-
other was cut at greater intervals. The grass in a third lysi-
meter was cut in the seed stage of growth while that in the
fourth lysimeter received no top cutting during the season. The
growth behavior of the grasses was similar to that reported
in Technical Bulletin 219, Growth Behavior and Maintenance
of Organic Foods in Bahia Grass. The percentage of nitrogen
in the top growth showed a downward trend from the different
cutting treatments in the following order:-Cut frequently, cut
less frequently, cut in seed stage, and receiving no cutting treat-
ment.
The quantity of nitrates in the leaching collected from these
lysimeters at intervals during the growing season was in the
reverse order of the cutting treatments given the grasses. The
highest leachings of nitrates was obtained from the grasses not
cut during the season and gradually decreased with the fre-
quency of cutting of the top growth.

GROWTH BEHAVIOR AND COMPOSITION OF TRANS-
PLANTED BAHIA GRASS AND BAHIA GRASS
UNDER PASTURE CONDITIONS
S(Hatch Project No. 99)

This project as outlined and reported on in previous annual
reports has been completed and the results will be reported in
Bulletin 219.

GROWTH BEHAVIOR OF BAHIA GRASS
(Hatch Project No. 100)

A part of the work of this project is completed and will ap-
pear in Bulletin 219, while other phases of the project are still
under way, especially those that have to do with the effect of
frequency of cutting or grazing on root development and compo-
sition. Plots of Bahia grass are being grown under conditions
so controlled as to make possible a study of the entire root de-
velopment.






Annual Report, 1930


LAWN AND GOLF GRASS STUDIES
(Hatch Project No. 42)
This project has been discontinued with the publication of
Experiment Station Bulletin 209, "Lawns in Florida".
A report on the golf grass investigational work is being pre-
pared for the United States Golf Association, which supplied
the funds for this work.

VARIETY TEST WORK WITH FARM CROPS
(Hatch Project No. 56)
Variety test work with the following crops was conducted
during the year: Corn, cowpeas, oats, soybeans, sorghum, mil-
let, sugarcane, pigeon peas, vetch, and rye. Twenty-three co-
operative corn variety tests embracing 10 of the outstanding
varieties are well placed over the corn growing area of the state
this year.
Corn Variety Test:-For the past eight years the Experintent
Station has conducted corn variety tests at Gainesville and at
various places in the state. The results of these tests were sum-
marized during the past winter and 10 of the leading varieties
were selected for further tests in cooperation with farmers in
central and northwest Florida. Twenty three of these tests,
covering a large number of soil types and variable moisture
and climatic conditions are in progress.
Records of growth, yield, weevil injury, and other notes will
be taken at the end of the season. It is hoped that the results of
these tests over a period of years will lead to a better under-
standing of the value and adaptability of the several varieties
to the peculiar soil and climatic conditions found in many sec-
tions of the state.

CROP ADAPTATION TESTS
(Hatch Project No. 107)
The project is in cooperation with the Forage Crop Office of
the United States Department of Agriculture and has to do with
the testing of new plants which might be useful for forage, pas-
ture, or soil improving purposes. During the year there were
plantings made of 458 different kinds of plants classified as
follows: Crotalaria 86, pigeon peas 130, miscellaneous legumes
91, grasses 80, and winter legumes 71.






Florida Agricultural Experiment Station


Among the more promising plants are several species of Cro-
talaria which look like possible forage crops and several strains
of pigeon peas which look good for forage and soil improvement
purposes. An effort is being made to increase seed of these
more promising plants.
Miscellaneous Tests-Small Grain Adaptation and Top-dress-
ing Experiments-These tests were begun with a view to de-
termining the adaptation of Fulghum oats, Abruzzi rye, Blue
Stem wheat, and Tennessee beardless barley to West Florida
soils and climate and to measure their response in seed produc-
tion to applications of nitrate of soda. Two farmers in Leon
County on Orangeburg soils were selected for the tests. The
results of the test on Mr. H. N. Hansen's farm are given in
Table I.
TABLE I.-RESULTS OF TOP-DRESSING SMALL GRAIN WITH VARYING
AMOUNTS OF NITRATE OF SODA.

Oats Rye Wheat

Wt. in I Bushels Wt. in Bushels Wt. in Bushels
Treatment sheaf per sheaf per sheaf per
per acrel acre per acre acre per acre acre

No top-dressing ........ 1,633 I 16.6 1 1,416 4.0 1,525 I 4.9
50 lbs. nitrate of soda.. 3,158 27.0 3,049 7.5 1,851 8.3
100 lbs. nitrate of soda 5,118 66.9 3,458 10.4 2,614 6.0
150 lbs. nitrate of soda.- 5,554 46.8 4,356 12.1 2,940 6.4
200 lbs. nitrate of soda.. 5,772 38.9 5,227 17.5 3,049 6.2


RATIO OF ORGANIC TO INORGANIC NITROGEN IN MIXED
FERTILIZER FOR COTTON
(State Project No. 159)

In view of the difference in cost of organic and inorganic nitro-
gen and the necessity of economical production of cotton, it
seems appropriate to investigate the efficiency of the two types
of nitrogen commonly found in mixed fertilizers for this crop.
Also, in the light of past experiences there seems to be a pos-
sibility of increasing the efficiency of inorganic nitrogen through
withholding part of the nitrogen in the mixture at planting and





Annual Report, 1930


applying as a side application just after chopping. Accordingly,
experiments permitting of the above studies were located in
Alachua, Jackson, Washington and Walton counties on soils pre-
dominating in these sections of the state.
With the cooperation of the county agents reliable farmers
interested in cotton growing were selected to cooperate with
the Experiment Station.
Through close supervision of the tests and a study of the re-
sults over a period of years it is hoped that an efficient and
economical program of nitrogen fertilization can be worked out.

SOURCES OF NITROGEN AND RATES OF APPLICATION
OF NITROGEN FROM DIFFERENT SOURCES AS
TOP-DRESSING FOR OATS
(State Project No. 97)
In the sources of nitrogen test, nitrate of soda again gave the
greatest increase in yield for both October and November planted
oats. The November planting yielded higher than the October
planting.
In the rates of application of nitrate of soda top-dressing tests
the 200 pounds per acre application gave the highest increase in
yield for the October planted oats while the 300 pounds per acre
application gave the highest increase in yield for the November
planted oats. In this test the October planting yielded higher
than the November planting.

CROP ROTATION STUDIES WITH CORN, VELVET BEANS,
SWEET POTATOES, AND PEANUTS
(Hatch Project No. 55)
This six-phase crop rotation experiment was temporarily
brought to a close at the end of the crop season 1928, due to a
shortage of funds. It has been inactive during the past year.

IMPROVEMENT OF CORN THROUGH SELECTION
AND BREEDING
(Purnell Project No. 105)
Selection Within Self-Fertilized Lines and Their Recombina-
tion:-The breeding plot in 1930 includes 2,017 selfed lines and
36 crosses. The more promising selfed lines were continued by
self-pollination. The crosses represent combinations of a few





Florida Agricultural Experiment Station


of the better selfed lines in the 1929 breeding plot. Self-pol-
linations were made in these crosses to begin new selfed lines.
Corn Breeding by the Ear-row Method :-Twelve ear-remnant
rows of Tisdale and 15 ear-remnant rows of Wilson Yellow Dent
were planted in 1930. Since isolated plots are not easily avail-
able, these rows were recombined by hand pollination. The
recombined material will be included in yield tests next season.
Yield Tests:-The yield test of 1930 includes 25 entries.
Records are being taken on the yields of both roasting ears and
dry grain on eight of the entries, while records of dry grain only
are taken on the remainder. This test includes the better va-
rieties from previous tests and a number of recombinations of
inbred lines. No changes in the recommendations in last year's
report are to be noted.
Sweet Corn Breeding:-A number of crosses between sweet
corn and our better selfed lines of field corn are being grown
this season. Self-pollinations have been made in these hybrids
to begin selfed lines of sweet corn which possess some of the
desirable characteristics of our native varieties of field corn.
General:-The seed ears produced in 1929 were harvested
during the month of August and stored in a metal grain bin.
The corn was very high in moisture and showers were frequent
at harvest time. But the corn dried rapidly in the metal bin.
Tests showed that the temperature inside the bin averaged about
20 degrees higher than the outside. It seems that the metal
grain bin provided with adequate ventilation is a very satis-
factory storage chamber for seed corn and similar material
which must be harvested during the rainy season.
The instruments recording soil and air temperatures, relative
humidity, precipitation and duration of sunshine have been kept
in continuous operation.

EFFECT OF TIME OF PLANTING OF CORN ON FORAGE
AND GRAIN YIELD
(State Project No. 106)
This is the fourth year now that monthly plantings of an early
and a late maturing corn have been made in February, March,
April, May and June. For the past three years the February
planting of both the early maturing variety and the late ma-
turing variety has yielded best. May and June plantings of






Annual Report, 1930


corn in the latitude of Gainesville have not been satisfactory
on Norfolk sandy land.

CORN FERTILIZER EXPERIMENTS
(State Project No. 163)
The large number of soil types, the wide variety in climatic
and moisture conditions, together with observations and the
results reported by farmers from the use of many kinds of fer-
tilizers for corn, seem to necessitate investigations that should
lead to a more judicious use of commercial fertilizer on corn.
Comprehensive experiments have been started on several of the
leading soil types in central and northwest Florida. Six experi-
ments embracing 60 to 80 plots each are in progress. The plants,
approaching maturity, are giving indications of a large difference
in the efficiency of many of the fertilizer practices under in-
vestigations.
Sources of Nitrogen Test on Corn:-Twelve sources of nitro-
gen are included in a test in Leon County and in Washington
County on farms selected through the assistance of the county
agents. The minerals were applied on duplicate plots when the
corn was about 40 days old. Yield records will be taken at the
end of the season.

PEANUT AND CORN FERTILIZER EXPERIMENTS
(Hatch Project No. 16)
This project was continued with virtually the same results
as in previous years; that is, very little profit was derived from
the use of any of the various kinds or quantities of fertilizer
used for peanuts.
It is planned to publish in bulletin form all peanut fertilizer
work covering a period of three to nine years at the close of one
more year's work.
The corn fertilizer experimental work continues to show that
for most Florida soils on which work has been conducted, nitro-
gen applied as a side-dressing to corn when it is six to seven
weeks old is most profitable. This nitrogen seems to be most
effective when in the form of quick-acting soluble material like
nitrate of soda, calcium nitrate, or sulphate of ammonia and at
the rate of 75 to 150 pounds per acre.






Florida Agricultural Experiment Station


EFFECT OF LANDPLASTER OR GYPSUM (CaSO,.2H20)
ON HAY AND SEED PRODUCTION OF
PEANUT VARIETIES
(Hatch Project No. 43)

This experiment was inactive in 1929 due to the fact that the
Artillery Unit of the University was using some of our experi-
mental land. The experiment is actively under way this year
and a final report on the use of landplaster will likely be pre-
pared for publication at the end of this season.

PLANT BREEDING-PEANUTS
(Hatch Project No. 20)
TABLE II.-OBSERVATIONS ON SEVEN SELECTED STRAINS OF SPANISH PEA-
NUTS AND ONE UNSELECTED STRAIN OF FLORIDA SPANISH PEANUTS
GROWN AT GAINESVILLE, FLORIDA.
6 Dry Basis* Air Dry*

Strain 0Oa '' "
Number c|1 c Wl 0 W @

N P4 P., .,q M

4427 ............... 961 1,152 45.0 28.8 15.8 80.7 0.99
172411 ............. 875 1,225 44.7 28.8 16.1 77.3 0.88
16233 ............... 958 1,511 44.6 29.4 16.6 78.3 0.83
44217 ............. 1,009 1,535 43.1 28.1 16.1 75.7 0.72
153118 ............. 862 1,453 44.1 27.2 17.5 78.3 0.85
14183 .............. 878 1,260 44.2 27.9' 16.1 74.2 0.83
61611 ................ 882 1,477 44.7 28.1 15.2 74.8 0.77
Fla. Spanish.... 747 1,408 45.2 29.7 15.9 77.2 0.75

*Grown at Gainesville in 1922
Breeding by Selection:-Seven strains of White Spanish pea-
nuts selected from a plant-to-row test in 1921 are being retained.
The data available on these strains are summarized in Table II,
in a comparison with an unselected lot of Florida Spanish pea-
nuts. It is believed that this check strain is a fair representative
of farm run Spanish peanuts. Each of the selections produced a
higher yield of nuts than the check strain over the eight-year





Annual Report, 1930


period. The average increase amounts to 22.8%, while the high-
est yielding selection shows an increase of 35% over the check
strain.
These seven strains and the check strain are being tested
again this season with a selection from the Texas Station and
another unselected lot of Spanish peanuts. All of the available
seed of the selections was planted for increase.
Breeding by Hybridization and Selection:-This work is be-
ing continued as outlined in the previous report. In so far as
it is possible with present facilities, tests are being made on
the length of the dormancy period in the hybrid seed. It is
necessary to grow these hybrid progenies through three or
four more generations of natural self-pollination before plant
selections may be expected to produce true breeding progeny.
The large Brazilian peanut, Arachis nambyquarae, has been
crossed with a number of different strains of the common peo-
nut, A hypogaea. The hybrid progeny appear fully fertile, in-
dicating that breeding by hybridization and selection may be pos-
sible with these two species.

THE EFFECT OF POTASH ON THE YIELD AND
QUALITY OF PEANUTS
(State Project No. 138)
Thirty-five different potash formulas are being tested on
Spanish peanuts. A 3-10-2 fertilizer at the rate of 600 pounds
per acre was the most profitable last season while a 5-10-12 at
the 600 pound per acre rate gave the greatest increase in yield
of peanuts but was not profitable due to cost of fertilizer. The
experiment is being repeated this year. Laboratory tests on the
quality of the peanuts are being conducted. The experiment is
a joint project in which the,Agricultural and Scientific Bureau
of the N.V. Potash Export My. of Amsterdam, Holland, through
their American representatives, is cooperating.

DATE OF SEEDING AND PHOSPHATE REQUIREMENTS
OF WINTER LEGUMES AND THEIR EFFECT
ON SUBSEQUENT CROPS
(State Project No. 153)
Through the hearty cooperation of county agents and farm-
ers, 13 winter cover crop tests were started in October and No-
vember of 1929. These tests are outlined to determine the phos-










TABLE III.-THE EFFECT OF SUPERPHOSPHATE ON THE GREEN WEIGHT YIELD PER ACRE OF WINTER LEGUMES.


Treatment


Austrian peas-

300 Ibs. super phosphate..

0 Ibs. super phosphate..

600 Ibs. super phosphate..

Monantha vetch-

300 Ibs. super phosphate..
0 Ibs. super phosphate..

600 Ibs. super phosphate..

Hairy vetch-

300 lbs. super phosphate..

0 lbs. super phosphate..1

600 lbs. super phosphate..


Jackson County
R. Powell's J W
Farm McKnight's
Farm


lbs.

10,464

2,450

12,676



6,153

2,296

9,852



5,615

2,518

6,023


lbs.

10,396

6,244

11,162


10,039

3,181

10,209



10,532

4,645

11,706


Washington County
Fred Cope's F. T. Wells' E. D. Martin's
S Farm Farm Farm


Ibs.

10,822

7,452

9,988


6,687

4,423

5,478



4,883

3,488

5,632


lbs.

15,603

7,332

15,824



13,714

6,721

13,714



9,964

6,091

11,996


Ibs.

10,720

5,530

8,848



4,764

2,552
4,764



5,700

3,403

5,190


Average


W.


lbs.

11,601

5,802

11,700



8,271

3,835

8,803



7,337
4,029

8,109


3.










0
t?3





Annual Report, 1930


phate requirements of winter legumes and their general value
on a number of the leading soil types of the central and north-
western part of the state. Each test is followed by corn or
peanuts, the yield of these crops to be taken as a measure of
the value of the winter cover crops.
Austrian winter peas, Monantha vetch, and hairy vetch were
planted in each test and fertilized with varying rates of super-
phosphate. Plantings were also made at different dates.
The results thus far indicate that October plantings are bet-
ter than November plantings and that satisfactory growth can
not be expected from seedings made in December.
In Alachua, Union, and Bradford counties there was an increase
in yield of each crop as a result of phosphate applications, how-
ever, the increase was not consistent, necessitating further
studies before a reliable program of fertilization can be worked
out. In Jackson and Washington counties in Northwest Florida
these crops showed a consistently marked response to phosphate
applications as will be noted in Table III.
It will be noted that 300 pounds of superphosphate per acre
was practically as effective in increasing the yield as 600 pounds.
Austrian peas made consistently higher green weight per acre
than Monantha vetch or hairy vetch. Representative samples
of these crops were weighed in the field and afterwards dried in
an oven and analyzed at the Experiment Station. The data
shows Austrian winter peas contained a higher percentage of
moisture than Monantha vetch or hairy vetch and that hairy
vetch contained a slightly higher percentage of total nitrogen
than Austrian peas or Monantha vetch.

WINTER LEGUME STUDIES
(Hatch Project No. 53)
The winter legume studies consist of a study of phosphate
requirements, date and rate of planting, the effect of time of
turning under winter legumes on succeeding crop growth and
yield, and cotton-corn rotation with and without winter legumes.
Superphosphate at the 400 pounds per acre rate seems advis-
able on land not previously well phosphated.
No exact statement as to best date of planting can be made
until further work is done, though it seems that late September
and early Ocober plantings if made during favorable seasons





Florida Agricultural Experiment Station


will give good results. Rate of seeding for hairy vetch can vary
between 20 and 30 pounds per acre, while for Austrian peas the
rate should vary between 30 and 50 pounds per acre. The rotation
work with winter legumes in a cotton-corn rotation will have
to be carried on a number of years to get reliable results. Suf-
fice it so say that all of these tests are now located on perma-
nent plots and will be carried on over a long series of years.




















Fig. 1.-Oats in a cover crops experiment in Jefferson County, Florida.
This non-leguminous winter crop follows a summer crop of Crotalaria
spectabilis. Note (in foreground) the large quantity of organic mate-
rial returned to the soil by the Crotalaria.

SUMMER COVER CROP STUDIES
(Hatch Project No. 54)
Work on this project at the Main Station is still inactive, due to
lack of available land since giving up the land formerly used for
the experiment to the University Artillery Unit. However, work
is in full force on this project at the Citrus Experiment Station
at Lake Alfred and at nine points in the citrus belt in coopera-
tion with citrus grove owners. Crotalaria striata continues to
be the outstanding summer cover crop for citrus groves at the
Citrus Experiment Station at Lake Alfred. A report of pro-
gress will be found under Project 83, at that station.





Annual Report, 1930 47

GREEN MANURE STUDIES
(Hatch Project No. 98)

This project as outlined in previous annual reports has been
completed and a report has been published in Soil Science 28:
347-371, 1929. A complete report will appear as a technical
bulletin of the Florida Experiment Station in the near future.
In the meantime interested parties can obtain the report as given
in Soil Science by writing to the Experiment Station at Gaines-
ville.
Lysimeter studies on green manure crops are still in progress
and are yielding some interesting information on rate of decom-
position and leaching.





Florida Agricultural Experiment Station


ANIMAL HUSBANDRY

Wilmon NeweU, Director.
SIR: I submit the following report of the Department of
Animal Husbandry for the fiscal year ending June 30, 1930.
Respectfully,
A. L. SHEALY,
Head of Department.


DAIRY HERD MANAGEMENT
The herd continues to be federal accredited as free from tuber-
culosis. Blood tests show every animal negative to the Bang
organism (contagious abortion). Regular dipping under fed-
eral regulations for eradication of the cattle fever tick in this
county began on March 1. Effect of dipping upon milk yield of
the dairy cows is being tabulated.
The dairy herd sires are being proved by cooperation with
the breed associations in obtaining official production records
of their progeny. This includes a study of transmitting ability
and also involves bringing the old herd records up to date from
the time when these records were first kept. All cows are milked
twice daily on test.
Three cows completed Register of Merit records during the
year, as follows:
Majesty's Florida Sue-
715642-2 yrs. 4 mo................. 7,847 lbs. 4.88% 383.19 lbs. fat
Majesty's Lassie Sue-
602497-5 yrs. 7 mo................... 7,330 lbs. 5.01% 367.23 lbs. fat
*April Knight's Coomassie-
339512-13 yrs. 7 mo............... 7,937 lbs. 4.45% 353.37 lbs. fat

RELATION OF CONFORMATION AND ANATOMY OF THE
DAIRY COW TO HER MILK AND BUTTER-
FAT PRODUCTION
(State Project No. 140)

Work on this project has been conducted by Dr. R. B. Becker
and Dr. W. M. Neal. Their report follows.
Measurements and records of three mature cows, Nos. 98, 156,
and 177, past usefulness in the Experiment Station dairy herd,
*This cow failed to qualify but made a creditable record for her ad-
vanced age.





Annual Report, 1930


were obtained and have been forwarded to W. W. Swett, leader
of the cooperative project, Bureau of Dairy Industry, Washing-
ton, D. C. With four records obtained last year, the Florida Sta-
tion has contributed seven animals to this work.

SOYBEAN SILAGE FOR DAIRY COWS
(Hatch Project No. 135)
Work on this project has been conducted by Dr. R. B. Becker,
Dr. W. M. Neal, and Mr. C. R. Dawson. Their report follows.
Otootan soybeans, drilled at the rate of 0.28 bushel per acre
April 29, 1929, were replanted early in May due to cutworm
damage. Cutworms were destroyed with poison bran mash
prior to the second planting. Soybeans were harvested August
21-23, 1929, when the third buds were in blossom, caterpillar
damage to the foliage necessitating harvest at this time. Al-
though considerable soybean forage was left on the ground, a
yield of 4.33 tons per acre was put into the 10-foot monolithic
concrete silo.
Samples of fresh soybeans, and of the silage, upon analysis,
showed slight losses in moisture, ether extract, and nitrogen-
free extract, and an apparent increase in crude fiber due to the
ensiling process (bacterial and enzymic action in the silo, as well
as evaporation). Complete weights of silage recorded in a study
of silo capacity showed 23.3 to 54.1 pounds of silage per cubic
foot, varying with depth in the silo.
Computation of the first year's feeding trial with 8 cows
showed one pound of No. 1 alfalfa hay practically equivalent
to 3.25 pounds of soybean silage, when used with a basal ration
of corn silage, and mixed grain (corn, bran, velvet bean feed
meal, and "good" or 36% cottonseed meal). The cows consumed
2.25 lbs. of common salt and 0.71 lbs. of bone meal per animal
per month during the feeding trial.
Because of their erect growth, Biloxi soybeans are being
grown this season. This study will be continued three years
before drawing conclusions, except that the soybeans made
silage of good quality, palatable to the cows.





Florida Agricultural Experiment Station


DEFICIENCIES IN FEEDS USED IN CATTLE RATIONS
(Purnell Project No. 133)
Work on this project has been conducted by Dr. R. B. Becker
and Dr. W. M. Neal. Their report follows:
Field study has been continued, locating the ranges on which
cattle become affected with so-called "salt sick", observing the
conditions under which it occurs, and the physical symptoms of
the cattle. Character of the range where the condition never
occurs, and upon which cattle recover, is being compared with
affected areas. Samples of native wiregrass from unfertilized
pastures are being obtained at monthly intervals on selected
representative "affected" and "healthy" ranges. A laboratory
is being equipped, and analytical work begun, with attention to
proximate analyses and mineral constituents of the grasses and
of the feeds employed in the feeding trials.
Post mortems have been conducted on four affected and four
healthy cattle to observe gross anatomical conditions, while
specimens preserved by Dr. C. F. Ahmann, are being used in his-
tological comparisons. No uniformity in parasitic infestation has
been found, nor is sand always present in quantity in the di-
gestive tract of affected cattle.
Natal grass hay was obtained from a farm in an affected
area. Two advanced cases of salt sick cattle produced upon
this hay were carried through to post mortems. Five calves
with a known feed intake from birth, will soon be of sufficient
age to use on this hay.

SWINE HERD MANAGEMENT
The swine herd is maintained under the "sanitation system"
in order to reduce the danger from disease, especially internal
parasites. The brood sows and pigs are kept on clean ground
at all times. By clean ground is meant land which has been
planted to some annual field crops which require cultivation, or
sown to such crops as oats or rye which require the preparation
of the soil before sowing.
By allowing the pigs to graze on crops grown on land previ-
ously cultivated, more pigs will be raised per brood sow, the
pigs will grow off faster and will be more uniform in size. The
swine herd affords a good means of demonstrating the im-
portance of raising pigs under the "sanitation system".





Annual Report, 1930


COMPARISONS OF VARIOUS GRAZING CROPS WITH DRY
LOT FEEDING FOR PORK PRODUCTION
(Hatch Project No. 136)
Crops of (1) peanuts and corn, (2) peanuts alone, (3) corn
alone, (4) chufas, (5) peanuts and sweet potatoes are being
grown for use in feeding tests during the 1930 fattening period.
Two-acre fields are being used in each case and eight shotes of
uniform size and breeding will be turned into each field as these
crops reach the proper grazing stage. Eight shotes will be fed
in a dry lot in order to make comparisons with the shotes fat-
tened upon the grazing crops. All the field crops to be used for
fattening purposes in this test made satisfactory growth except
the sweet potatoes. It was hoped that the shotes could be turn-
ed into all five fields on July 1, 1930, but only the following crops
will have reached such a stage of maturity as to enable the
grazing period to begin on that date: (1) field of peanuts and
corn, (2) field of peanuts alone, (3) field of corn alone. Spanish
peanuts were used due to the fact that it was desired to obtain
very early grazing. An early maturing variety of corn also was
used.

FATTENING FALL PIGS FOR SPRING MARKET
(State Project No. 160)
Fields of (1) peanuts alone and (2) chufas alone are being
grown at this time,-these crops to be used in fattening pigs
during the winter months. The area of each field is two acres.
It is planned to begin grazing in these fields about January 1,
1931. Eight shotes will be used in grazing each field during the
fattening period. In order to make comparisons between fat-
tening shotes on the grazing crops and dry lot feeding, eight
shotes will be dry-lot fed a ration consisting of corn and fish
meal.

THE VALUE OF GRAZING FOR FATTENING CATTLE IN
BEEF PRODUCTION
(Hatch Project No. 137)
During the grazing season of 1929 there were 20 steers used
in this experiment. These steers were divided into four lots of
five each and were grazed on the following pasture plots: carpet
grass; Bermuda; Bahia; and a plot of mixed grasses which in-





Florida Agricultural Experiment Station


eluded carpet, Bermuda, Bahia, and Dallis grasses. Each plot
was 3.5 acres in size. The steers were weighed on two consecu-
tive days during the grazing season and on three consecutive
days at the close of the test period. The steers were taken off
the pasture plots on November 21, 1929.
The following results were obtained:


Kind of Pasture

Carpet grass ........
Bermuda grass ....
Bahia grass ..........
Mixed grasses-
Carpet, B er -
muda, Bahia,
and Dallis
grasses) ........


Average Gain i Average Pounds of Beef
Per Steer Daily I Produced Per
During Grazing Gain Acer
Period In Pounds Acre
165 pounds .65 236 pounds
171 pounds .67 243 pounds
189 pounds .74 270 pounds



197 pounds .77 280 pounds
I I


The 1930 grazing period began March 21. Twenty steers are
being used during this period, the steers divided into five lots
of four each. Ten of the steers are grade Herefords and 10 are
scrubs. The same pasture plots are being used as during the
1929 grazing season with the addition of a pasture of centipede
grass. The steers are being weighed as during the previous
year. All steers used in this experiment were wintered under
uniform feeding conditions.

COOPERATIVE BEEF CATTLE GRAZING STUDIES
Through an agreement with the J. C. Penney-Gwinn Corpora-
tion a beef cattle grazing experiment is now being conducted at
Penney Farms, Florida. This project began May 20, 1930, when
28 steers were weighed and put on 240 acres of unimproved pas-
ture land which was previously burned. At the same time
another lot of 28 steers were weighed and put on 240 acres of
unimproved pasture land which was not burned over previous
to stocking with steers. Two 40-acre tracts are being developed
into improved pastures for beef cattle. The Agronomy Depart-
ment of this Station is cooperating in this work and their phase
of the work is shown in the report of that department.





Annual Report, 1930


THE COST OF WINTERING STEERS PREPARATORY TO
SUMMER FATTENING ON PASTURE
(State Project No. 122)
Twenty steers were put on test January 7, 1930, and fed until
March 22, 1930-a total of 74 days. Peanut hay alone was used
as the wintering ration. The steers had access to the hay ad
libitum. The following data show the results of the test:
Number of steers on test............................................. ........... 20
Cost of peanut hay............................................... ......................$ 20.00 per ton
Amount of peanut hay eaten during the test period............... 19,347 pounds
Average amount eaten per steer per day.................................. 13 pounds
Average cost of wintering per steer per day..........................$ .13
Initial weight of entire lot of 20 steers............................... 11,600 pounds
W eight at close of feeding period................................................ 11,215 pounds
Loss in weight during feeding period-.......................... .... 385 pounds
Average loss per steer for entire feeding period................. 19.25 pounds
The steers were weighed once each week during the feeding
period.
ANAPLASMOSIS IN CATTLE
(Purnell Project No. 149)
Work on this project has been conducted by Dr. D. A. San-
ders. His report follows.
Work on anaplasmosis began October 1, 1929, with head-
quarters in West Palm Beach. A field survey was made which
included a thorough study of suspected cases of anaplasmosis.
Numerous blood examinations were made in these studies.
Since it appeared highly probable that the disease was spread
by an intermediate host, an insect or external parasite of some
sort, it was deemed necessary to erect insect-proof stalls in
which to keep the experimental animals. These stalls were com-
pleted March 15, 1930. Immediately after the stalls were con-
structed a cow was put in one of these stalls. This animal was
injected intravenously with large amounts of blood taken from
two cows in a dairy herd in which the disease had been prevalent
for two years. In 32 days after injection the cow came down
with a typical case of anaplasmosis.
: The symptoms of the disease are as follows: suppression of
milk production; high fever; increased pulse rate and respira-
tions; reduced hemoglobin content, and a reduction in number
of red corpuscles; the presence of numerous anaplasma organ-
isms located at the margin or near the center of the red blood
corpuscles-these bodies usually occur singly in the corpuscles;
a greenish yellow coloration of all visible mucus membranes;





Florida Agricultural Experiment Station


greatly dejected appearance of affected animal, and rapid loss
of flesh. The high temperature persists for a period of three
weeks in many cases.
Four susceptible cows were shipped from the Main Station
herd in Gainesville, since the cattle in the Station dairy herd
were known to be free from anaplasmosis. Various blood suck-
ing insects are being used at this time in an effort to determine
just what connection such insects might have in the spread of
this disease. This work has not progressed to the stage where
it would be possible to say just what insect or insects are im-
portant in spreading the disease.

PARALYSIS OF THE DOMESTIC FOWL
(State Project No. 119)
Work on this project has been conducted by Dr. E. F. Thomas.
His report follows.
Some of the studies started in 1928 and 1929 have been com-
pleted and others are still in progress. Paralysis was not pro-
duced by the continuous use of antiseptics in the drinking water.
This experiment extended over a period of 12 months. The anti-
septics used were potassium permanganate, one-third teaspoon-
ful of the crystals to each gallon of water; bichloride of mercury,
six grains to each gallon of water; a hypochlorite solution, one
tablespoonful to each gallon of water. The water was mixed up
fresh daily and all birds, including the control birds, consumed
about the same amounts of drinking water daily.
No cases of paralysis have been produced to date by feeding
various tissues from diseased chickens to chickens of a suscept-
ible age in which an enteritis has been artificially produced. This
experiment is being continued since not enough birds have been
used to give conclusive results. Another experiment is being
conducted in attempting to find the causative agent by feeding
different tissues from paralyzed chickens to birds known to be
heavily infected with chronic coccidiosis. No conclusions have
been reached in this experiment, since it has not been in pro-
gress a sufficient length of time to permit of definite conclusions
being drawn.
In studying the autopsy records of all paralyzed chickens ex-
amined during the time this work has been in progress it has
been observed that an enteritis was present in every case of the
disease.





Annual Report, 1930


KIDNEY WORM OF SWINE
(State Project No. 92)
This project is inactive at the present time. Dr. D. A. Sanders
was working on it up to the time of his transfer to the work on
anaplasmosis in cattle. It is hoped that the study can be re-
newed next year.

DIAGNOSTIC LABORATORY REPORT
In addition to conducting research work on the above projects,
the department has maintained a diagnostic laboratory, and dis-
eased specimens from the various classes of livestock have been
sent to the laboratory for diagnostic reports on same. These
specimens are received from practicing veterinarians, officials of
the State Live Stock Sanitary Board, and livestock owners them-
selves. During the year 3,150 diagnoses were made. Numerous
inquiries concerning diseases of livestock, including poultry,
have been received and information given on these cases.

VETERINARY SERVICE
Veterinarians in this department devote part of their time
in diagnosing and treating diseases which occur in the horses of
the University Field Artillery Unit, R.O.T.C., and in the livestock
belonging to the College Farm and Agricultural Experiment
Station.





Florida Agricultural Experiment Station


CHEMISTRY
Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Chemistry for the fiscal year ending June 30, 1930.
Respectfully,
R. W. RUPRECHT,
Chemist.


The work of the Department during the past year was carried
on largely along the same lines as during previous years.
A new laboratory to study the iodine content of Florida-grown
crops was equipped in the basement of the Main Station with
funds donated by the Florida Iodine Research Committee. In
co-operation with the Agronomy Department, a new nitrogen
laboratory was equipped in the basement of the Main Station. A
new fertilizer mixing and storage house was built. At the Citrus
Station, two rooms in the basement of the laboratory building
were furnished and equipped as chemical laboratories. This will
greatly add to the facilities for work at this station.
As in the past, this department is cooperating with the Agron-
omy Department in green manure and pasture studies, with
the Plant Pathology Department in the study of fertilizer re-
quirements of tobacco, with the Horticultural Department in a
study of pecan fertilizer requirements, and with the United
States Department of Agriculture in truck fertilizer experiments.
A considerable number of soils were tested for degree of acid-
ity and a number of samples of rock tested for phosphate and
lime.
DIEBACK OF CITRUS
(Adams Project No. 21)
The work on this project was somewhat interrupted due to
Dr. J. F. Fudge's absence on fruit fly work and his subsequent
resignation. With the appointment of Dr. B. R. Fudge, the work
has shown satisfactory progress. While no positive statements
can as yet be made, analysis of leaves and twigs of dieback and
normal leaves tends to show that dieback is definitely associated
with the nitrogen metabolism of the plants.





Annual Report, 1930


DETERMINATION OF THE EFFECT OF VARYING
AMOUNTS OF POTASH ON THE COMPO-
SITION AND YIELD AND QUALITY
OF THE CROP
(Hatch Project No. 22)
The grove at Lake Alfred had a fair crop of grapefruit and
oranges. As stated in previous reports, no differences in crop
yields due to different amounts of potash have been found. The
trees receiving the higher amounts of potash did not have as
good a color on the foliage as did the low potash trees. A sim-
ilar condition was observed in other groves where high amounts
of potash were used in comparison with lower amounts. The
poorer color may be the result of less nitrogen being assimilated
where the higher amounts of potash were applied. At present
we have no data on this point. Due to the presence of the Med-
iterranean fruit fly, no fruit from Lake Alfred could be shipped
to Gainesville, so no storage tests were made.
In the potato experiment at Hastings, doubling the amount of
potash did not increase the yield or grade of the potatoes.
The extremely unfavorable season made it impossible to draw
any conclusions in regard to increasing amounts of potash on
tomatoes.

DETERMINATION OF THE FERTILIZER REQUIREMENTS
OF SATSUMA ORANGES
(Hatch Project No. 36)
The experiment at Marianna was conducted as outlined in the
1929 annual report. The grove made satisfactory growth and
did not suffer severely from the cold. Due to curtailment of
funds, it was impossible to visit the grove as often as was de-
sirable for observations as regards cold injury.

DETERMINATION OF THE EFFECT OF VARIOUS POTASH
CARRIERS ON GROWTH, YIELD, AND
COMPOSITION OF CROP
(Hatch Project No. 37)
The experiments at Lake Alfred and Vero Beach were con-
tinued. (For descriptions of these experiments, see 1924 Re-
port, p. 50R, and 1925 Report, p. 30R.) The grove at Lake Al-
fred made a normal growth and bore some fruit. Diameter





Florida Agricultural Experiment Station


measurements of the trunks of the trees show no differences in
the growth of the trees on the various plots except on Plot 1.
The poorer growth on this plot has been due to two causes, first,
most of the trees in one row were attacked by salamanders which
severely injured the roots and, second, the lower corner of the
plot is heavily infested with maiden cane which probably used
much of the fertilizer intended for the trees.
The grove at Vero Beach made a fair growth and produced
a good crop of fruit. All of the plots have made about the same
increase in growth and to date no great differences in crop yields
have been found. Analysis of the fruit indicates that the source
of potash has not influenced the composition of the fruit.
In the Hastings potato experiment, the muriate of potash gave
just as good a yield as the sulphate. The tomato experiments at
Bradenton comparing sources of potash were ruined by too much
rain. The experiment with pecans had such a small crop of nuts
that no conclusions could be drawn.

STUDY OF FERTILIZER REQUIREMENTS OF CITRUS
TREES WHEN GROWN ON MUCK SOIL
(State Project No. 66)
The experiment was continued as outlined in previous reports.
The grove has made a very satisfactory growth. It is believed
that water control has been secured so that no further trouble
from this source should be experienced.

COMPOSITION OF CROPS AS INFLUENCED BY FERTIL-
IZATION AND SOIL TYPES-PECANS
(State Project No. 67)
Most of the pecan experiments had a very small crop, too small
and scattered to draw any conclusions as to the effect of the fer-
tilizers. Samples were obtained wherever the crop was large
enough and these are being analyzed.

TO DETERMINE THE CAUSE OF POOR CROP GROWTH
DUE TO LIMING SANDY SOILS
(State Project No. 93)
The work on this project has been completed and presented to
the faculty of the Graduate School of the University as a thesis
for a Master's Degree by Mr. J. B. Hester. This will shortly be
published as a Station bulletin.






Annual Report, 1930


The results of the study may be summarized as follows: The
replaceable calcium content of Norfolk medium fine sand was in-
creased by the application of lime in the form of calcium carbon-
ate and hydrated lime while the replaceable potash was not sig-
nificantly affected. The ratio of the replaceable calcium to the
replaceable potash in the limed soil was such as to preclude a suf-
ficient supply of potash for the plants without the application of
potash.
The increase in the replaceable calcium together with the low
stage of biological activity in these soils brought about a con-
dition of the soil solution in which the plant could not obtain
sufficient quantities of potash to supply its needs even with ap-
plications of nitrogenous fertilizers well above the average. The
potash starvation was overcome by the application of potash
salts or by increasing the biological activity in the soil.

EFFECT OF VARIOUS FERTILIZER FORMULAS
(State Project No. 94)
The experiment with citrus at Lake Harris comparing low
phosphate fertilizers with normal phosphate fertilizers was con-
tinued. The grove made a good growth but to date no differences
are apparent.
The potato experiment at Hastings was continued. Due to
very unfavorable weather, only a light crop was harvested. The
best yield of potatoes was obtained where urea was the only
source of nitrogen while the urea and tankage plots had the sec-
ond best yield. The inorganic sources of nitrogen, nitrate of
soda, sulphate of ammonia and leunasalpeter, gave better yields
than when these were used in combination with fish scrap or
tankage. As in previous years, top-dressing with nitrate of soda
did not increase the yield. Cutting the phosphate content of the
fertilizer 4% did not affect the yield nor did doubling the amount
of potash. The muriate plots gave just as good a yield as the
sulphate of potash.
In cooperation with the United States Department of Agricul-
ture Bureau of Chemistry and Soils, a number of experiments
with truck crops were conducted.






Florida Agricultural Experiment Station


CONCENTRATED FERTILIZER STUDIES
(State Project No. 95)
The concentrated fertilizer experiment with citrus at Lake
Alfred conducted in cooperation with the United States Depart-
ment of Agriculture was continued. No outstanding differences
in either tree growth or yield are apparent. Only a light crop
was harvested.
In the Lake Harris experiment the urea and leunasalpeter
treated trees are making just as good growth as the check trees
receiving the usual fertilizer.
Two experiments, one with Irish potatoes and one with to-
matoes, were conducted comparing some of the synthetic nitro-
gen compounds. These experiments were made possible by a
grant from the Synthetic Nitrogen Corporation. Due to very
unfavorable weather, neither experiment gave a normal yield.
Therefore, no conclusions could be drawn.

DETERMINATION OF THE EFFECT OF GREEN MANURES
ON COMPOSITION OF SOIL
(Adams Project No. 96)
The work on the green manure or cover crop project has been
somewhat enlarged. Nitrate determinations at different depths
were made on the soil of plats where winter cover crops of Aus-
trian peas, vetch, or oats were grown. The nitrate content of the
soil of the plats where leguminous winter cover crops were grown
and incorporated was higher than where non-legumes or no cover
crop was grown. The winter cover crops during their growth
utilized the nitrates formed from a summer cover crop which
had been incorporated in the soil. This was particularly true of
the non-leguminous winter cover crops.
Studies on the different methods of handling the cover crop
are being continued. Analyses of the soil and the plants of the
first series have been completed and they indicate a more effec-
tive utilization of the nitrogen in the mulched tanks and a util-
ization over a longer period than that where the cover crop was
incorporated with the soil.
The large lysimeters show that where a leguminous cover crop
is grown, followed by a cash crop, such as corn, there is a dis-
tinct saving in plant food as well as water leached. The lysi-
meter planted to a rotation containing a summer legume, winter






Annual Report, 1930


non-legume, followed by a cash crop, showed less than half as
great a loss of potash and magnesium as did the lysimeter on
which a cash crop and no cover crop was grown. There was also
a conservation of nitrogen in the lysimeter growing a cover crop.

EFFECT OF VARIOUS FERTILIZER TREATMENTS AND
OF SOIL AMENDMENTS ON TOMATOES
(Hatch Project No. 112)
Work on this project was carried on in cooperation with the
Bureau of Plant Industry, U.S.D.A. Five cooperative experi-
ments were conducted, four on the East Coast, at Dania, Holly-
wood, and Homestead (two), and one on the West Coast at
Bradenton on the grounds of the Field Station. Three concen-
trated mixtures with and without manganese, copper, nickel,
zinc, and magnesium were used in comparison with the usual
commercial fertilizer in two of the experiments. In both cases
the commercial fertilizer gave somewhat higher yields than the
concentrated mixtures without the addition of manganese. In
two experiments the growers' own fertilizer was used with and
without the addition of manganese. In both cases yields were
increased where manganese was used.
In the fifth experiment, comparisons were made between a
concentrated fertilizer alone; the same fertilizer with the ad-
dition of manganese sulfate; the same fertilizer with the ad-
dition of manganese, nickel, copper, zince, and iodine; a com-
mercial fertilizer alone, and with the amendments mentioned
above. The results were too inconsistent for conclusions to be
drawn.
In the same experiments the effects of wood ashes and cal-
cium hydroxide in addition to the fertilizer were also used. Both
wood ashes and calcium hydroxide increased the yields some-
what. The results of earlier experiments will be published as
Bulletin 218.

EFFECT OF FERTILIZERS AND SOILS ON COMPOSITION
OF TRUCK CROPS
(State Project No. 141)
A total of 120 samples of vegetables have been collected and
prepared for analysis. Some of these have been collected from
the fertilizer experiments carried out under Project No. 94.






Florida Agricultural Experiment Station


About 51 of the above samples have been partially analyzed. The
work has not progressed far enough to draw any conclusions.

STUDY OF IODINE CONTENT OF FLORIDA-GROWN CROPS
(State Project No. 161)
Work on this project was begun in February. To date, we
have collected and prepared for analysis about 150 samples of
fruits and vegetables grown in different sections of the State.
Some of these have been analyzed. The results indicate that
our fruits and vegetables contain as much iodine as is found
elsewhere.

A STUDY OF THE DECOMPOSITION OF FOREST, RANGE.
AND PASTURE GROWTHS TO FORM SOIL
ORGANIC MATTER
(Adams Project No. 166)
Work on this project has just begun. Preliminary work with
Bahia sod grown in lysimeters and fertilized with nitrate of soda
has shown that when the grass is cut frequently, every week.
more nitrogen is utilized than when it is cut less frequently.
The grass that was allowed to mature before cutting used the
least amount of nitrogen. The heavy utilization of the nitro-
gen by the frequently cut grass has apparently caused a defloc-
culation of the soil by the sodium of the sodium nitrate, as col-
loidal material has come through in the drainage from these
tanks.
Preliminary work on forest soils has indicated that the chief
effect of burning is to deplete the organic matter and nitrogen
in the soil.






Annual Report, 1930


COTTON INVESTIGATIONS

Wilmon Newell, Director.
SIR: I submit the following report for the Cotton Depart-
ment for the fiscal year ending June 30, 1930.
Respectfully,
A. F. CAMP,
In Charge Cotton Investigations.


Work in the Cotton Department was considerably upset dur-
ing the past year by the Mediterranean fruit fly campaign and
other matters, the writer was absent from July 1, 1929, to April
1, 1930, Mr. Grossman from July 1 until June 20, and Dr. Walker
from July 1 to September 1; all occupied with duties in connec-
tion with the Mediterranean fruit fly campaign. Dr. Walker was
transferred to the Plant Pathology Department on November 1
to work on watermelon diseases and his position has not been
filled. Dr. Carver continued his breeding work in the regular
way and Mr. Calhoun did a small amount of boll weevil work
under the direction of Mr. Grossman, but most of the other pro-
jects were temporarily suspended. In cooperation with the De-
partment of Horticulture, an experimental cold storage plant was
erected and will be used in further studies on boll weevil hiberna-
tion.
VARIETY TESTING AND BREEDING
(State Project No. 57)
During the season of 1929, cotton variety tests were planted
in four different localities. The results are given in the table at
the top of page 64.
During the present season (1930) 19 varieties are being test-
ed at Gainesville, Campbellton, and Laurel Hill. Several demon-
stration plots, including two selected strains of Council Toole
and two of Lightning Express, were planted in Jackson and
Washington counties. Breeding work to secure better adapted
strains of cotton for Florida will be continued. Special attention
is being given to wilt resistance, productiveness, length and uni-
formity of lint, and picking qualities. Selected strains of Coun-
cil Toole and Lightning Express are being increased for dis-
tribution to Florida farmers next season.






Florida Agricultural Experiment Station


RESULTS OF COTTON VARIETY TESTS CONDUCTED IN 1929, YIELDS SEED COTTON
PER ACRE (POUNDS).


Location of Tests


Variety



Trice, Miss. Sta. ......
Rowden No. 40 ........
Miller .....................
Willis ........................
Lightning Express....I
Express 432 .............
Acala 31 .................
Wilds No. 2 ..............
Cleveland 54 ............
Chappell's ..................
Sikes .......................
Cook 307-6 ..............


FIELD TESTS


Gainesville Campbellton

1,187 1,611


1,162
1,145
1,156
1,008
1,189
1,301
744
1,202


1,044
1,202
1,407
1,407







1,407


WITH COTTON-SPACING
OF PLANTING TESTS
(State Project No. 74)


Blounts-
town Laurel Hill

354 1,572
..... 1,282
612 1,669
...... 1,766
490 1,621





500 .......


...... 1,693
i.... 1,403
I


AND TIME


This project was suspended 1929-30 and resumed for 1930-31.

CONTROL OF COTTON INSECTS
(State Project No. 75)

During the fall of 1929, an effort was made to get cotton stalks
destroyed in various communities on a community basis. This
was unsuccessful, however, as the growers were not willing to
go to any extra expense in the growing of cotton. The cotton
stalks on the experimental plots at Gainesville were all de-
stroyed, however, except for a small area left as a check and all
of the stalks in the plantings at Penney Farms were also destroy-
ed. Observations on the emergence of weevils into the plots
during the spring of 1930 indicated that the work done in de-






Annual Report, 1930


stroying the stalks had a great influence on the emergence of the
weevils and from this standpoint the results were very encourag-
ing.
Further studies were carried on with reference to spring pois-
oning of cotton to poison hibernated weevils. Indications in the
spring of 1929 were that the poisoning program outlined in 1928,
consisting entirely of mopping, did not give a satisfactory con-
trol of weevils in the experimental plots. In the spring of 1930
the 1928 program of mopping was supplemented in several plots
with the application of dust, after heavy squaring had started.
The results so far indicate that a much better control will be
obtained in this way than was obtained in 1929 with mopping
alone.
Following up former hibernation experiments, 23,096 weevils
were put up in four cages in the fall of 1929. Two of the cages
were placed in dense, swampy locations and two in the apiary
which is in the lighter woods. These weevils were placed in hi-
bernation from October 1-10, which is about as early as stalks
could be destroyed on good land in this state. This experiment
is thus comparative with the stalk campaign, which was adopted
during the fall of 1929. Weevils had to be imported from Geor-
gia, as no satisfactory supply was found near Gainesville, and
their emergence during the spring of 1930 is being observed but
the data have not yet been calculated.

COTTON PHYSIOLOGY-COTTON RUST
(State Project No. 76)
This project was suspended 1929-30.

COTTON DISEASES-SEEDLING DISEASES
(State Project No. 77)
This project was suspended 1929-30.

COTTON DISEASES-COTTON WILT
(State Project No. 78)
See Project 57.





Florida Agricultural Experiment Station


COTTON PHYSIOLOGY, NUTRITION AND GROWTH
(State Project No. 79)
This project was suspended 1929-30, and resumed 1930-31.
Fertilizer tests are being made along the following lines: Rates
of applying phosphorus and potash, ratio of organic to inorganic
nitrogen, the amount and time of applying nitrate of soda, and
the rate of application of a complete fertilizer.

STUDIES IN INHERITANCE OF COTTON
(State Project No. 101)
The results of the cotton inheritance studies through the sea-
son of 1928 were published in an article entitled "The Inherit-
ance of Certain Seed, Leaf and Flower Characters in Gossypium
hirsutum and Some of Their Genetic Interrelation." Jour. Amer.
Soc. of Agr. Vol. 21, No. 4, pp. 467-480, April, 1929. The article
reported the genetic interrelation between the characters red
leaf, petal spot, naked seed, buff anthers, and okra leaf, between
green seed fuzz and brown seed fuzz; between naked seed and
fuzzy-tip seed, and between five naked seed characters from five
unrelated strains of cotton. Further data are being secured on
the interrelation of these characters. Other studies being con-
ducted are on the inheritance of dilute petal spot, inheritance of
plant variegation, and the genetic relation of the character green
seed fuzz to the characters petal spot, buff anther, and red leaf.






Annual Report, 1930


ENTOMOLOGY
Wilmon Newell, Director.
SIR: I submit the following report of the Department of En-
tomology for the fiscal year ending June 30, 1930.
Respectfully,
J. R. WATSON,
En tomologist.


VELVET BEAN INSECTS
(Adams Project No. 7)
As in the previous year, the main interest with the velvet
bean caterpillar was its attacks on peanuts in the Everglades
and on soybeans. Since the location of an entomologist at the
Everglades sub-station, the study of the control of this insect
on peanuts has been placed in his hands. In the case of soybeans
it would appear that the logical method of control is to plant soy-
beans so early that they can be harvested before the caterpillar
becomes abundant (in August in central Florida). In view of
the decreasing use of the velvet bean on Florida farms it would
seem inadvisable to devote any considerable part of the attention
of the Department to this subject.
Effective July 1, 1930, this project will be closed out as an
Adams fund project and the work will be continued at the Ever-
glades Station under State funds.

FLORIDA FLOWER THRIPS
(Adams Project No. 8)
Due to the rainy weather during the spring, there was no
heavy infestation of thrips in citrus groves. The tobacco thrips
seriously injured narcissus plants in some fields. A study was
made of thrips infesting sugarcane and corn. A survey of the
Thysanopterous fauna of the state was continued. The object
of this is to make the identification of the species more accurate
and to investigate the character of the damage inflicted by vari-
ous species.
ROOT-KNOT INVESTIGATIONS
(Adams Project No. 12)
The main line of work in the control of root-knot has been cen-
tered around the starvation of nematodes during the summer by






Florida Agricultural Experiment Station


growing Crotalaria on infested lands. The Crotalarias have sev-
eral advantages over velvet beans, previously recommended for
this work, in that they grow upright, making cultivation much
easier, and grow under a wider range of soil conditions, and are
not as seriously attacked by insects as velvet beans.

INTRODUCTION AND STUDY OF BENEFICIAL INSECTS
(Hatch Project No. 13)
In the acre of cane planted on the Citrus sub-station grounds
at Lake Alfred the infestation was so low that it did not seem ad-
visable to attempt to introduce the Cuban parasitic fly (Loxaph-
aga) this year. For some undetermined reason the infestation
has been light over most of southern Florida.
At the Citrus sub-station we have started to raise mealy bugs
with the intention of introducing the mealy bug ladybeetle, Cryp-
tolaemus, from California.
The Chinese ladybeetle (Leis), also introduced from California
several years ago, was found to have become thoroughly estab-
lished in a citrus grove in Orange County. The beetles were ex-
tremely abundant in this grove in April feeding not only on
ladybeetles but on the gum exuded from diseased citrus trees.

LARGER PLANT BUGS ON CITRUS AND TRUCK CROPS
(Adams Project No. 14)
Under the leadership of Mr. Bratley a detailed life history
study is being made of the more troublesome of our larger plant
bugs, including the pumpkin bug, the leaf-footed plant bug, and
the club-legged plant bug. The life history of the pumpkin bug
was thoroughly studied by Dr. Drake in 1917, but it is very desir-
able to continue this work throughout the year. Dr. Drake's
work included from April to July only. It is particularly impor-
tant to determine the common host plants for these bugs
throughout the season so that information may be obtained on
which one may best base control measures by breaking the con-
tinuity in food plants.
The great interest shown in Crotalaria as a cover crop has
made very desirable the study of the insect fauna of this plant,
particularly including the bella moth which sometimes interferes
seriously with the production of seed. This work is also under
the leadership of Mr. Bratley.






Annual Report, 1930


Effective July 1, 1930, this study will be transferred from the
Adams fund to State funds and the work continued as a State
project.
STUDIES OF THE BEAN JASSID
(Adams Proect No. 28)
The investigations of the bean jassid (Empoasca fabae) were
conducted along the lines followed the previous year. Plots 20
by 20 feet were treated, the sprays being applied with a com-
pressed air knapsack sprayer, and dusts with a hand duster. To
determine the relative value of the different insecticides all jas-
sids were counted on the plants in a five foot row. All the ma-
terials tested reduced the number of insects but only a part of
them were of practical value as a control measure. Flowers of
-sulphur dusted on the plants greatly reduced the number of
jassids, though there was little evidence that any were killed.
Also 4-4-50 bordeaux reduced the number of jassids materially.
The pyrethrum sprays consistently gave greater immediate kills
and showed more lasting effects than did nicotine sulphate syrays
in connection with bordeaux mixture, with soaps or with the new
activators which are so effective when used against aphids.

THE GREEN CITRUS APHID (Aphis spiraecola)
(Adams Project No. 60)
This project continues to be one of the major projects of the
Department. The infestation of the green citrus aphid was
heavier than for any year since 1925. This was undoubtedly due
to the climatic conditions. Our studies have shown that the
temperature during January is a critical factor in determining
the numbers of this aphid the following spring. The rainfall is
a secondary factor. January with a mean temperature above
60, free from heavy frosts, with a moderate rainfall, but not
heavy, driving rains, supplies ideal conditions for the initiation
of a heavy infestation.
Mr. Tissot's work with the green citrus aphid was carried on
Sas in the previous year. Weekly counts were made of predators
and parasites when the aphids were present in sufficient num-
bers. Aphids on quince and apple were secured from Monticello
and transferred to citrus where they continued to thrive for
several generations.
Further tests were conducted using some of the insecticides






Florida Agricultural Experiment Station


recently placed on the market. Using Grandpa's Wonder Spray,
So-Fyne, and Penetrol as spreaders, kills of 98% or better were
obtained with Black Leaf 40 at dilutions as low as 1 part to
10,000. The tests indicated that the pyrethrum sprays are not so
consistently effective as is nicotine sulphate with spreaders. An
extract of Tephrosin was tested as an aphicide but the results so
far have been only negative.
Mr. Tissot has continued his survey of aphids of the state in
connection with this project.

CONTROL OF DECIDUOUS FRUIT AND NUT CROP INSECTS
(State Project No. 82)
The work on nut crop insects was continued at the Monticello
laboratory under the leadership of Mr. Fred W. Walker. How-
ever, Mr. Walker was on the Mediterranean fruit fly work until
December 15, 1929, with the result that very little work was done
on pecan insects the first half of the year. During the summer
of 1929, a laboratory building was constructed by the County
Commissioners of Jefferson County for the use of pecan investi-
gations.
NUT CASE-BEARER
During the present season this insect has done much damage
to the pecan crop. In some groves as much as 60 percent of the
crop was destroyed by the first brood of this insect. During past
years experiments were conducted for the control of this insect
with summer sprayings, but only negative results were obtained.
Mr. Walker's careful observations of this insect's method of
feeding show that it habitually discards the outside of the pecan
nut with its coating of arsenicals when it bores into the nut.
This prevents it from getting a lethal dose of arsenicals. Mr.
Walker has forced them to dig an entrance hole into as many as
three sprayed nuts in succession, after which they completed
their development in a normal manner. It would seem that a
dormant winter spray is the most profitable line of attack. Some
promising results along this line have been obtained, but as yet
no definite recommendations can be made for general use.
THE LEAF CASE-BEARER, Acrobasis spp.
There are two species of leaf case-bearers commonly found in
groves and the third is common in nurseries. The most common,
A. juglandis, is largely responsible for the poor setting of nuts





Annual Report, 1930


this year. The over-wintering larvae tunnel into the unopened
buds, which they often destroy. Checks made on buds from one
grove showed that 92.2 percent of the buds which failed to open
had been attacked by this insect.
THE SHUCKWORM, Laspeyrasis caryana
Larvae were much later in pupating this spring than usual,
and consequently the adults were a little later in appearing. The
first brood was mostly on hickory nuts and in phylloxera galls.
Experiments show that plowing under the shucks in the early
spring is the most effective method of control. When the pupae
were buried to a depth of an inch or more in sandy loam, very
few emerged. The larvae, however, had to be buried at a depth
of at least four inches in a light sandy loam or two inches in a
heavy clay soil in order to get an 80 percent kill or better. This
emphasizes the importance of plowing the orchards after the
larvae have changed into pupae in the spring.

LIFE HISTORY STUDIES OF Pycnoscelus Surinamensis
(Linn), THE ROACH WHICH IS THE INTERMEDI-
ATE HOST OF MANSON'S EYEWORM
(State Project No. 108)
During the past year little work was done with this insect. A
search of poultry yards and barnyards in the vicinity of Gaines-
ville produced only a few specimens insufficient to carry on any
life-history experiments. Since this roach is of tropical origin,
it would seem advisable to carry on the experimental work with
it in one of the laboratories in the southern part of the state
where it is more prevalent and where the winter weather is
warmer than at Gainesville.

MEALY BUGS
(State Project No. 155)
Mealy bugs were unusually abundant during the past season.
It was found that the pyrethrum compounds gave better control
than the nicotine compounds. The use of Penetrol as a spreader
also increased the efficiency of the nicotine sprays.





Florida Agricultural Experiment Station


GREEN SPIDER (Tetranychus bimaculatus) ON
ASPARAGUS PLUMOSUS
(State Project No. 156)
Under a special appropriation from the Legislature for the
purpose, the study of various insects of ornamentals has been
undertaken. The major project under this heading is the study
of and control measures for the green mite (Tetranychus bimacu-
latus Harvey) of Asparagus plumosus. For the prosecution of
this work, Dr. J. W. Wilson was employed and located at Pierson,
in the infested area. He began work on December 1, 1929. The
City of Pierson donated the use of the City Hall as a laboratory,
and an outside insectary suitable for Asparagus plumosus culture
has been built.
Dr. Wilson has carried out studies on the life history of the
insect, and its host plants. The insect in question is a common
pest of blackberries, cotton, etc., but in only one section of the
state has it attacked Asparagus plumosus. This suggests that
we have to do here with a new biological race which has taken
to Asparagus. This idea is strengthened by the fact that Dr.
Wilson has taken this mite from blackberries and other plants
and transferred it to Asparagus, and it promptly died. Whereas
the reverse transfer from Asparagus to blackberries was easily
made. The only other host plant of this apparently new biologi-
cal race is the black nightshale, Solanum nigrum.
Along lines of control it has been found that sprinkling the
"ferneries" with water two or three times a week is a very ef-
fective means of control and economical except for the initial
cost of installing the irrigation system. Only a small number of
ferneries at present are provided with such a system. Derrisol
and the combination of pyrethrum compounds with white oil
emulsions have been found to be effective sprays for this mite.
A dust is much to be desired, but none has been found which is
effective.
INSECTS OF ORNAMENTALS
(State Project No. 157)
Other work on ornamentals included the study of the polka
dot wasp-moth, a very severe pest of oleanders in the southern
part of the state, and a rubber tree delofiator. This work, and
the study of other caterpillars damaging ornamentals, has been
taken up by Mr. Bratley.





Annual Report, 1930


INSECTS AND OTHER ANIMAL PESTS OF WATERMELONS
(State Project No. 162)
Mr. Carlos C. Goff has been employed to take up the study of
watermelon insects at the Leesburg field laboratory. The melon
aphid is one of his main projects. He began work on February 1,
1930, and is carrying on life-history work with the melon aphid,
including the study of predators and parasites, and especially
the host plants of the melon aphid to discover the source of in-
festation in watermelon fields. An outdoor insectary has been
constructed for the work. This work will be closely correleted
with the work on the green citrus aphid under Project No. 60.















Fig. 2.-The Experiment Station's watermelon and ornamental field labora-
tory, established during 1930, Leesburg, Fla.

Mr. Goff has also taken up the problem on the control of the
mice in watermelon fields. By destroying the seeds as soon as
planted, these mammals constitute a major problem of the water-
melon grower. This work under the leadership of Mr. Goff is
to be closely correlateed with similar work on the Everglades
rats, which is being conducted by Professor Lobdell, of the Ever-
glades Experiment Station, and should prove useful in the con-
trol of other rodents, including moles and rabbits, as well as
mice. For several weeks previous to the completion of the Lees-
burg laboratory, Mr. Goff was stationed at the Everglades sub-
station, where he studied primarily the striped cucumber beetle.






Florida Agricultural Experiment Station


HOME ECONOMICS

Wilmon Newell, Director.
SIR: I submit the following Report of the Department of Home
Economics Research for the fiscal year ending June 30, 1930.
Respectfully,
OUIDA DAVIS ABBOTT, Chief.


The work of the department for 1929-30 has been a continua-
tion of the projects previously reported.
Work was begun July 1, 1929 on the new project, The Rela-
tion of Growth to Phosphorus, Calcium and Lipin Metabolism as
Influenced by the Thymus.
An addition to the animal house has been built which will give
facilities for caring for a greater number of animals.
A report by projects follows:

DETERMINATION AND IDENTIFICATION OF ORGANISMS
WHICH CAUSE THE SPOILAGE OF CANNED
VEGETABLES IN THE SOUTH
(Purnell Project No. 69)

In the determination of the cause of spoilage of canned corn
in the South, examinations have been made on several lots of
corn canned in this laboratory and on corn sent to this laboratory.
It has been found that there are two distinct forms of spoilage
due to insufficient sterilization. In the one case the cans swell;
the contents are putrid and the odor is disagreeable. In the
other form of spoilage the cans do not swell, but the corn becomes
soft, packs in the jars, and shows hydrolysis of starch.
An organism having most of the characteristics of Bacillus
graveolans Gottheil and belonging to the B. subtilis group has
been identified as the causative agent in this latter (non-gas-
forming) spoilage. It has been found that this organism is not
always killed when the temperature of the autoclave is held at
2400 F. for 60-75 minutes if the corn is packed in the jars in the
proportion of 4 to 1 or even 3 to 1. Because of the resistance of
this organism, it was at first believed to be a thermophile, but
later work has shown that its resistance is due to the resistance
of its spores in colloidal substances.





Annual Report, 1930


The addition of tartaric, acetic, hydrochloric, or phosphoric
acid to the corn so that the pH of the water added is between
pH 2.4 and pH 3 prevented the spoilage of the corn. When the
acid was omitted the percentage of spoilage of corn canned under
identical conditions was more than 50 percent.

DETERMINATION OF WHETHER CHLOROPHYLL, CHLO-
ROPHYLL ALPHA AND BETA, THE PETROLEUM ETHER
EXTRACTS OF THE YELLOW PIGMENTS OF ALFALFA,
CAN BE USED AS A SOURCE OF VITAMIN A IN ANIMAL
NUTRITION
(Purnell Project No. 70)
In order to determine the effect of pigments and extractives on
animal nutrition it is necessary to know the chemical content of
the basal ration. The following determinations have been made
on the basal ration.
1. Cystine, tyrosine, and tryptophane content of extracted
and unextracted casein, and casein purified according to Ham-
marstein.
2. The solubility and digestibility of the above caseins.
3. Ash analysis of alfalfa, lean meat, and yeast.
Ether and alcoholic extracts of corn pollen, carrots, and alfalfa
have been fed as a source of Vitamin A. The animals fed on
these extracts improved for a time but were not in good state
of nutrition.
Histologic studies have been continued. Special work has
been done on the glands in the throat and oral cavity which are
subject to infection.
Feeding experiments have been conducted to determine
whether lecithin, a necessary component of the animal body, can
be synthesized by the animal. This compound is not included in
the basal ration. This work is still in progress.

A STUDY OF SOME OF THE CONSTITUENTS OF CITRUS
FRUITS, LOQUATS, ROSELLE, AND GUAVA;
PECTINS, OILS AND GLUCOSIDES
Purnell Project No. 71)

The study of the pectins (prepared as given in the last report)
was continued.
The properties listed were determined:





Florida Agricultural Experiment Station


1. The viscosity as a function of the pectin content.
2. The jelly-strength as a function of the pectin content.
3. The viscosity as a function of the pH.
4. The jelly-strength as a function of the pH.
5. The jelly-strength as a function of sugar content.
6. The pectic acid content of the pectins.
7. The total acidity of the pectins.
8. The ash content of the pectins.
The comparison of the pectins as to pentosan content and as
to methoxyl content is still in progress.

THE DETERMINATION OF THE NUTRITIONAL STATUS OF
RURAL SCHOOL CHILDREN IN FIVE REPRE-
SENTATIVE COUNTIES IN FLORIDA
(Purnell Project No. 72)
The work under this project has been completed and the re-
sults published in Bulletin 216.

THE RELATION OF GROWTH TO PHOSPHORUS, CALCIUM
AND LIPIN METABOLISM AS INFLUENCED
BY THE THYMUS
(Purnell Project No. 142)
Studies on the relation of the thymus gland to growth and
to calcium, phosphorus, and lipoid metabolism are being con-
tinued. In the series for growth studies the effects of feeding
the gland and the effects of injection of various extracts are
being observed. Caponized cockerels and castrated rats are
used. In the series for the study of the effects of the removal of
the thymus, rabbits are used.
In cooperation with the Department of Animal Husbandry,
histologic studies are being made of the thymus and other
glands and organs of animals on a low plane of nutrition.





Annual Report, 1930


HORTICULTURE

Wilmon Newell, Director.
SIR: I submit the following report of the Department of Horti-
culture for the fiscal year ending June 30, 1930.
Respectfully,
A. F. CAMP,
Horticulturist.


Work in this department was badly upset by the Mediter-
ranean fruit fly campaign. The writer was absent in connection
with this campaign from July 1, 1929 to March 27, 1930, and
much of his time up until July 1, 1930 was occupied with mat-
ters pertaining to the fruit fly work; Messrs. Blackmon and
Mowry were absent for the same reason from July 1 to January
1; and as all three had been absent for some time prior to July
1, 1929, there was more or less general disorganization in the
department. Some of the work had to be dropped entirely, but
most of the long-time experiments were kept going and most
of the correspondence was handled as heretofore. As a result of
the above situation, some of the report is very brief and in-
complete.
Funds accumulating from unspent salaries and expense funds,
as a result of the fruit fly campaign, have been utilized to con-
struct an experimental cold storage plant in cooperation with
the Cotton Department, which should be ready by fall.

OBSERVATION AND TESTING OF VARIOUS
CITRUS HYBRIDS
(Hatch Project No. 51)
All of the citrus hybrids under test, whose parentage is Pon-
cirus trifoliata in part, have demonstrated their hardiness, 150F.
causing no apparent damage. None of the hybrids of P. trifoli-
ata parentage, other than the Citrangequats, can be considered
as bearing edible fruits, although part of them can be utilized
to advantage in the making of "ades" and for like uses.
The rapid growth and cold-resistance of Citrange seedlings
and cuttings indicate the possibility of utilizing this hybrid as
a rootstock. It has been incorporated in the Satsuma rootstock
tests.





Florida Agricultural Experiment Station


In appearance the Citranguma is possibly the most striking
tree of any of the citrus hybrids under test. The tree is willowy
in growth like the Satsuma but larger, and is thornless. The
foliage and fruit are comparable in appearance to that of the
Satsuma but of larger size. The fruit is inedible, having too
great a percentage of the pungent P. trifoliata flavor.

TESTS OF DIFFERENT STOCKS AS ROOTSTOCKS FOR
SATSUMA ORANGES
(Hatch Project No. 81)
Low temperatures of the past winter severely injured a ma-
jor portion of the trees in this planting. Those trees, however,
which were budded on the Rusk Citrange showed much more
cold-resistance than did any on other rootstocks. Satsumas on
this stock are making a vigorous growth, indicating an adapta-
bility and congeniality to this rootstock as well as an ability to
withstand low temperatures without injury.

FUNDAMENTAL PHYSIOLOGY OF FRUIT PRODUCTION
(State Project No. 111)
Work on this project was completely suspended in April, 1929,
when the leader was called to Orlando to take part in the fruit
fly campaign and was not resumed until April, 1930. No report
was rendered for the year 1928-1929 and the report below is
largely material that would have been reported at that time,
under normal conditions.
Fruit measurements on Pineapple orange trees indicated no
relation between position on the tree and size. The trees were
divided into upper and lower halves and each half divided into
quarters and the fruits measured by quarters. A rough rela-
tion between the amount of fruit and the size was indicated,
although it was not always consistent. The indications are, how-
ever, that thinning of fruits might increase size if done early
enough.
An analysis of some fruit measurements indicated that the
standard deviation (probable error of one result), when calcu-
lated as a percentage of the size, is larger for small (immature)
fruit than for large fruit, thus indicating that more fruit would
have to be used in random sampling of small fruits than when
large fruits were used. This was true whether the diameters
or volumes were used in the calculations.





Annual Report, 1930


Following up previous work on the relationship between diam-
eter measurements and volume measurements in interpreting
growth, it was shown from the work of 1927 and 1928 on the
growth of fruits that the actual growth as indicated by the vol-
ume continued for two to three months after the curves of the
diameters indicated a virtual cessation of growth. In the early
stages of growth the curve of the diameters indicates a very
rapid growth but when the curve of volumes is worked out it is
found that the growth is very much slower than would be indi-
cated by the diameters.
A great deal of data along this line still remain to be worked
out, including the effect of applications of nitrogenous fertilizers
in the fall on the sizing of tangerines.
During the spring of 1930 experiments were conducted on
the effect of soil temperature on the germination of citrus seeds.
Grapefruit seed showed an optimum soil temperature in the
neighborhood of 320 C. and a maximum around 370 C. Grape-
fruit seed gave the most definite curve and the results in the
others are slightly irregular. Sour orange seed appear to have
a higher optimum, probably about 35-36', with a maximum
38-390 C., the maximum being definitely higher than for grape-
fruit. Sweet orange gave very irregular results but indicated
a relationship similar to grapefruit but with possibly a slightly
narrower range. Routh lemon reacted about like sour orange.
Measurements on the growth of the seedlings indicated that
other factors than soil temperature controlled the growth over
most of the range.

AVOCADO MATURITY STUDIES
(Purnell Project No. 139)
Work on this project was started July 1, 1929. Fruit of all
three strains of avocados, i.e., West Indian, Guatemalan, and
Mexican, was used in this year's work. It was too late in the
season by the time the work got started to get fully satisfactory
data, and the hurricane in south Florida further handicapped
the work through the destruction of fruit in that district. In
spite of this, however, some very satisfactory work was accom-
plished.
A study was made of the refractometer method for determin-
ing avocado oil content as developed by the Division of Fruit
Products, Agricultural College, University of California. This





Florida Agricultural Experiment Station


method was reported to be very accurate and comparable to the
ether extraction method, but, following the method in minute
detail, it has never proven satisfactory in the work here, inas-
much as the values obtained have never checked satisfactorily
with those obtained by the standard ether extraction method.
Temperature, size of sample, time of grinding, grinding ma-
terials, method of grinding, and amount of moisture present
were all taken into consideration, but under no condition was
it possible to get the values of this method to check within a
reasonable error with the standard ether extraction method.
The work is being continued and solvents other than Halowax
oil are being tried. This method is recommended as a substitute
for the ether extraction method, having in its favor its greater
speed and convenience. However, unless it can be made to check
more accurately than has been the case so far it will have to be
entirely discarded.
The relation of water and fat content to maturity and ripen-
ing of avocados was studied. It was found that the percent of
fat (green basis) increases considerably with the maturity of
the fruit while the moisture content decreases. When the fat
values are expressed on the dry basis (water-free) this decided
increase in fat content with maturity does not appear. There is
an increase, but this is small compared to the green pulp values,
thus indicating that the moisture content of the fruit must be
taken into consideration when determining the fat content of
avocados.
Avocados grown in the so-called Ridge Section of Highlands
County had a much higher percentage of fat and a much lower
percentage of moisture than those grown in South Dade County.
This comparison of analyses of fruit from different sections of
Florida is being continued.
In connection with the study of the oil content of avocados, a
study was made of other factors which may be found to be meas-
ures of maturity. In an effort to find some better method of test-
ing ripeness in the avocado than the oil content method, a com-
plete analysis of the fruit was made, including specific gravity;
moisture; percent of seed, skin, and pulp; total sugar, protein,
nitrates, crude fiber, ash, fat, etc.
The analyses were made using fruit picked over a period of
three months (the last three months of the season), which was
too short a time to give a comprehensive idea as to the changes
taking place in the composition of the avocados during the





Annual Report, 1930


growth cycle. The work is being repeated, and the sampling
Sand analyses are being started with the very young fruit (size
of a pea) and will be continued throughout the entire season.

TESTING OF NATIVE AND INTRODUCED SHRUBS AND
ORNAMENTALS AND METHODS OF THEIR
PROPAGATION
(Hatch Project No. 52)
Recent introductions which have shown themselves to be
adapted and of value as ornamentals include:
Ulmus pumila (FPI 61000)
Zelkova sinica (FPI 22985)
Cudrania tricuspidata (FPI 71304)
Cocculus laurifolius
Euonymus bungeanus (FPI 62418)
Cotoneaster salicifolia floccosa (FPI 62256)
Cotoneaster sp. (FPI 56304)

VARIETY, PROPAGATION AND PLANTING TESTS OF
PEAR, AVOCADO, JAPANESE PERSIMMON,
FIG AND OTHER FRUITS
(Hatch Project No. 58)
Several pears of Chinese origin (previously reported) are
fruiting for the first time this season. None have shown blight
infection. Pears of Siberian origin have proven unadaptable,
making little or no growth and all dying out within three years
after planting.
Fruit has set on several varieties of avocados of the Mexican
type, including the Fuerte. Those fruiting are mainly seedlings.
By close planting and without artificial heating they have with-
stood prevailing winter temperatures, including 150 F. in Janu-
ary, 1928, with little damage. Trees of the Guatemalan type
were all more or less severely injured by cold; of the Mexican
varieties, the Gottfried has proven least hardy.
The jujubes have definitely indicated their cold resistance to
be in the following order: Ziziphus jujuba, Z. mistol, Z. mau-
ritiana, the last being killed to the ground by 220 F. The above
species have made a very thrifty growth on Norfolk soils.
Of the figs grafted on the Ficus sp. (FPI 52406), the Green
Ischia variety seems to form the most congenial union with a
more vigorous growth following.





Florida Agricultural Experiment Station


VARIETY TEST OF BERRIES (Rubus spp.)
(Hatch Project No. 59)
The Advance blackberry this year has continued to make a
satisfactory growth with favorable yields. No other varieties
under test are showing any characteristics of outstanding value.
Most of the common northern varieties of blackberries have
not only shown a lack of vigor but are dying out. The Young-
berry produces fruit of excellent quality but in the test plot has
produced only in relatively small quantity.

COOPERATIVE COVER CROP TESTS IN PECAN ORCHARDS
(State Project No. 80)
A very light crop of nuts was produced in 1929 by the trees
included in the experiments being conducted under this pro-
ject. The trees are making satisfactory growth in the plots
planted to cover crops. The forcing into growth of the twigs
on the bearing trees in the plots planted to leguminous crops,
seemed to be much more decisive than in those plots without a
cover crop, and somewhat better than the plots with a non-
leguminous cover crop. Crotalaria spectabilis, weighed October
3, 1929, averaged slightly more than 21,000 pounds green ma-
treial per acre.
Austrian winter peas gave the best yield in the legume plots,
and oats slightly more than rye in the non-leguminous plots.

REJUVENATION EXPERIMENTS WITH NEGLECTED
PECAN ORCHARDS
(State Project No. 164)
There was a light crop of nuts produced by many of the trees
under this project in Clay County, but no conclusions could be
drawn from this fact.
The trees are making satisfactory growth.
That part of this project being conducted in Jefferson County
has been temporarily discontinued, because of lack of coopera-
tion.
The other part of the project is being continued.





Annual Report, 1930


FIELD STUDIES OF THE DISEASES AFFECTING THE
PECAN, INCLUDING CONTROL MEASURES
(State Project No. 44)
(Progress report is made by the Department of Plant Path-
ology under Project No. 4).

FIELD STUDY OF THE INSECTS ATTACKING THE PECAN,
INCLUDING CONTROL MEASURES
(State Project No. 45)
(Progress report is made by the Department of Entomology,
under Project No. 82).

VARIETY RESPONSE OF PECANS TO DIFFERENT SOIL
TYPES, LOCALITIES, ETC.
(State Project No. 46)
The behavior of varieties, previously reported, on different
soil types and locations, and in various parts of the state, is being
followed up. The varieties that are being included in ne* plant-
ings over the state are noted from time to time.
Top-working trees of undesirable varieties to those that are
considered to be better ones continues to be done, where trees
are properly located and the grower desires to increase nut pro-
duction.
There is a general increase in the number of pecan acres
planted to winter and summer cover crops. Austrian winter
peas and hairy vetch are, to a marked degree, becoming the lead-
ing winter cover crops, while Crotalaria spectabilis and velvet
beans are the important ones for summer planting.

COOPERATIVE FERTILIZER TESTS IN PECAN ORCHARDS
(State Project No. 47)
The trees in four of the experiments gave a fair yield of nuts,
while those in the other eight produced a very light crop of nuts.
The total production and growth of the trees in fertilized plots,
since the experiments were begun, has been greater in a ma-
jority of the plots than from the unfertilized plots. The 1930
crop prospects are much better for all experiments conducted
under this project than they were for 1929, but not quite so
good as for the crop of 1928.










TABLE IV.-YIELDS* AND MEASUREMENTS OF TUNG TREES IN FERTILIZER TEST PLOTS.
1927 1928 1929
S1929 Avg. Tree
Measurements
Fertilizer Material Av. Tree Yield Av. Tre Yield Av. Tree Yield 8-Yr.ee Average
Fertilizer Material i Tree Yield'
Single Cluster Sng Single Cluster Single Cluster Single C r
Type Type Type | Type Type |Type Type Type *
l b. l oz. lb. oz. lb. oz b. oz. lb. oz. Ib. I oz. lb. ] oz. I lb. I o. o z
Planted 1922
15 trees to plot
Nitrate of soda ..................................... 7 3 5 13 1 0 0o 1 8 1 5 66 61 41 3 4 7 1 9.4 1.21 15
Steamed bone meal ...................................... 2 2 4 4 9 3 1 9 | 1 15 3 | 11 4 I 61 3 | 3 3 1 | 10 8.9 ] 13.71 14.4
4-8-4. Sulphate of ammonia, 2%; dried
blood 2%; superphosphate; muriate
of potash .................................................. 3 2 8 5 10 4 2 0 0 12 4 3 12 4 10 2 12 11 9. 13. 14.7
Superphosphate ............................................. 14% 1 71 21 22 | 1 8| 1 91 2 [ 41 3 41 91 2 1 61 21121 8.211.41 12.4
Muriate of potash ..........................................I 11 2_1 2 141 ] 0 1 13 1 2 | 2 1 %) 1 7 5 I 3 _1 | 2 1 3 1 6 9.41 13.41 14
Superphosphate and ..................................... 1%1 1 21 1 21 1 1 213 i I 1 71 1 9 .8 114.11 14
Muriate of potash .......................................... 0 | 10 4 14 1 9 2 7 2 | 3 6 4 1 | 7 4 8 9.8 14.1 14.1
Manure ........................................... ............... 18 1 2 1 6121 2 20 4 1 8 2 10 | 20 1 5 | 2 8 1 9 1 3 14 1 5 | 12 10.2 114.4 15.8
Cheek (no fertilizer) .................................... 0 | I0 5 1 3 0 0 1 2 0 0 1 2 1 7 T 0 I215 3 11 1 1 9 1 2 111 8.3112.41 14.2
Planted 1923
12 trees to plot
Cottonseed meal .............................................. 1%1 I 2 I | 102 T 1 I
Steamed bone meal ........................................[ 1 3 7 3 2 3 1 10 0 3 2_| 8_ 13 _7 3 5 j 51 5 5 10.5 14 1 15.5
Lime only ......................................................... 3 1 12 2 7 0 1 3 1 11 3 | 8 0 5 7 51 3 7 3 1 11 9.9 1 11.91 12.5
5-8-4. Nitrate of soda, 2%; sulphate of
ammonia, 1%; cottonseed meal, 2%;
superphosphate; muriate of potash;
and lime, as above ................................ 3 0 4 12 4 4 0 4 9 4 8 14 7 10 5 5 5 10 10.7 1.1 15.6
Check (no fertilizer) ....................................1 0 0 0 14 1 31 3 0 0 | 5 1| 3 | 7 0 1 7 1 8 1 01 14 | 4 14 8.1 10.61 11.3
5-8-4 as above. No lime ............................ 8 | 4 1 8 1 6 1141 4 1 4 1 12 71 57 1 4 | 10 1 12 115 8 1 6 | 11 9 | 13 | 11.2 I15.1l 15.9
Manure ............................................ ................. 20 | 1 1 4 2 2 0 20 I 8311 5 5 12 6 6 2 71 4 1 13 9.71 12.5 12.8
5-8-4. Cottonseed meal, 2%; nitrate of
soda, 8%; superphosphate; muriate
of potash ..................... ...... : ............ 3 8 4 5 0 4 4 6 6 1 4 8 4 6 15 8 5 6 4 10.9 15.6 15.1
Steamed bone meal ......................................| 5 1 11 1 _4 5 1 5 5 21 5 41 4 5 |51 1 918 3 1 3 1 I 6 1 2 111.1 114.61 14
*All seed weights of air-dried hulled seeds.





Annual Report, 1930


VARIETY AND STOCK TESTS OF PECAN AND
WALNUT TREES
(State Project No. 48)
No additional varieties have been planted in the variety or-
chard since the last report.
A very light crop of nuts was produced in 1929, but the trees
made a good growth as indicated by trunk and twig measure-
ments at weekly intervals.
Crotalaria spectabilis produced an average of 24,300 pounds
of green material per acre which was cut into the soil with a
disk harrow.

VARIETY TESTS OF GRAPES
(Hatch Project No. 49)
Of the 61 varieties of grapes planted in 1923 only the follow-
ing are continuing in a condition of thrifty growth: Champanel,
Elvicand, Extra, Herbemont, Hermann Jaeger, Jacquez, Jaeger
43, Lukfata, Marguerite, Muench, Neva, R. W. Munson, Sabinal,
Salamander, and Valhallah.
The variety Extra grafted on the native Vitis munsoniana
rootstock has made a very satisfactory union and growth, the
plants now being in their fifth year.

PROPAGATING, PLANTING, AND FERTILIZING TESTS
WITH TUNG-OIL TREES
(Hatch Project No. 50)
Yields from the fertilizer test plots for the years 1927, 1928,
and 1929 are shown in Table IV. It will be noted that the great-
est increase in yield and tree size was from plots receiving a
complete fertilizer having an analysis of 5 percent ammonia,
8 percent phosphoric acid, and 4 percent potash. The nitrogen
of the fertilizer was derived from nitrate of soda 2 percent, cot-
tonseed meal 2 percent, and sulphate of ammonia 1 percent.
Production of the older 10 trees continues to show an increase,
the 1929 yield averaging 45 pounds 9 ounces hulled seed per tree.
The average annual tree yield for these trees over an 8-year
period-9th to 16th years-was 22 pounds 5 ounces of hulled
seed.
The average production of all Station plantings over a 3-year
period-1927 to 1929, inclusive-has been heavier on the so-





Florida Agricultural Experiment Station


called "cluster" type or variety than from the "single" type.
The largest individual tree yield was from a "single" type tree;
this tree is also the largest in size of any in the plantings.
Test plantings of approximately 11 acres have been made this
year in Alachua and Columbia counties for the purpose of defi-
nitely determining the comparative merits of seedling and
budded stock, and of "single" and "cluster" trees, both budded
and as seedlings.

RESEARCH IN FUMIGATION AND STERILIZATION
METHODS
(State Project)
(This Project Cooperative with State Plant Board)
Work on this project was suspended entirely when the Medi-
terranean fruit fly was discovered. Mr. Roy J. Wilmot returned
to the work on November 1, 1929, and spent a number of weeks
assembling data from experiments carried out just previous to
the finding of the Medfly. Mr. Ralph L. Miller started in the
work on May 1, 1930.
During the few months that fumigation research was carried
on, most time was spent studying the technique of the drawing
of samples through various kinds and lengths of tubing. On
the resumption of work considerable time was spent finding and
stopping leaks in the fumigation box and in equipping the box
with a new valve on the discharge vent. Some work was done
on the toxicity of hydrogen cyanide gas to houseflies and work
is now in progress to determine the lethal concentrations neces-
sary for various scale insects and whiteflies.
In 11 runs of a 1,000 cu. ft. room, where the gas is circulated
by being forced in through five 5" perforated tin pipes at the
bottom and drawn out at the top through similar pipes, the
concentrations of hydrogen cyanide gas, ranging from .28% to
.40%, did not vary more than .01% at eight different points in
the room when samples were taken simultaneously.
Five liter samples of HCN gas ranging in concentration from
.3% to .4% were drawn through lengths of rubber, copper, and
aluminum tubing ranging in length from 4 to 20 ft. There was
considerable loss of HCN in the rubber tubing, especially in the
longer lengths, while both the copper and aluminum had no ap-
preciable effect.






Annual Report, 1930


In connection with insect toxicity studies, a new and original
apparatus was designed and is now in use by which insects in
cotton stoppered glass tubes can be easily and quickly exposed
to an atmosphere of known concentration of HCN gas. House-
flies were killed in 2 min., 8 sec., when the hydrogen cyanide
gas, ranging in concentration from .34% to .40% was drawn
over them; they were killed in 2 min., 45 sec., at a 50% lower
concentration.
At the present time, toxicity studies of two species of scale,
one whitefly, and one army worm are in progress. Equipment
has been built for studying the effect of humidity on toxicity,
and other equipment is now being assembled for studying the
loss of HCN gas during fumigation by adsorption or absorption
on the materials being fumigated. Bean weevils, grain weevils,
mealy bugs, and cottony cushion scale are being reared for fum-
igation toxicity studies.

PHENOLOGICAL STUDIES ON TRUCK CROPS IN FLORIDA
(State Project No. 110)

The "time of planting" experiment for Irish potatoes was con-
tinued for the fourth consecutive year.
Table V is a summary of results for the season:
TABLE V.-SUMMARY OF RESULTS IN THE "TIME OF PLANTING" TESTS
WITH POTATOES, 1930.


Yields in Barrels per Acre Value per Acre, in
Plot Date -- --- Dollars
Planted Total % 1s % 2's' ie Sec's I Total

...............112/15/29 59.751 31.90| 53.7 14.84] 24.2 1255.201 74.20 330.40
1 1 1 1 I


B ................12/29/29 47.77
C ................ 1/13/30 44.45
D ................ 1/20/30 56.66
E* (Checks)l 1/27/30 47.20


2/ 3/30 39.64
2/10/30 29.07
2/17/30 27.83


24.981 52.3 11.30
19.70 43.9 12.82
28.10 49.7 15.22
18.6 38.2 14.70
14.7 37.3 11.10
7.5 25.8 8.40
8.5 29.9 8.70


23.7 149.88
29.5 118.20
26.7 196.70
31.5 130.20
28.27 102.90
29.16 45.00
31.96 51.00


45.20
44.87
49.46
44.10
30.52
18.90
19.57


195.08
163.07
246.16
174.30
133.42
63.90
70.57


A


*Data for planting E are mean values for all checks.
Plantings "A" and "D" are outstanding when compared with


I





Florida Agricultural Experiment Station


the other plantings, although the yield of marketable tubers
(No. 1's and No. 2's) is less than the best plantings in previous
years. This is the first time in the four years that an early
planting has ranked first in yield. Heretofore, plantings in late
January and early February have produced the best crops.
Planting "D" this year gave promise of the largest returns until
heavy rains, frost, and blight killed the vines prematurely. Of
course, all of the plantings were injured, but plantings "A",
"B", and "C" were more nearly mature at the time the adverse
growing conditions developed.
Potatoes were planted in dry and wet moss peat and in check
plots. Table VI shows the relative yields per acre.
TABLE VI.-COMPARATIVE YIELDS OF POTATOES FROM PLOTS RECEIVING DRY
Moss PEAT, WET MOSS PEAT, AND NO MOSS PEAT.

Treatment Yields Barrels per Acre Average Weight
Primes Seconds Primes (Grams)

Wet moss peat ............. 17.2 16.9 86.0
Dry moss peat .............. 17.1 11.0 76.2
Checks (no moss peat) 16.9 12.9 81.3

The differences shown are not significant in contrast to the
tests in 1928-29. In the rate of germination a marked advan-
tage was noted in favor of the wet moss, but shortly after the
sprouts appeared all the plots became wet, due to heavy rainfall.
The hill selection tests carried on for two years were discon-
tinued this year. It was found that the immature potatoes
when planted in Maine were slower in germinating and re-
mained green longer than the surrounding vines. They thus
became a good pasture for all the insect pests on the farm. Dis-
ease transmission from other plots was therefore very high.
The results during the two years indicated the desirability of
continuing the selection work in case they could be grown in an
isolated area in Maine to prevent disease infection by insect
pests. Such an arrangement is not feasible at the present time.

MULCH PAPER PROJECT
(International Paper Co. Cooperation)
Work on this project began September 15, 1929. Since then,
research on mulch paper has consisted of determining the most





Annual Report, 1930


effective time and method of application of the mulch paper for
some of the promising truck crops in relation to stimulation of
plant growth, yields, and economic production; the effects of
mulch paper upon soil temperature, soil moisture, and available
soil nitrogen; the effects of paper mulch as a control measure
for weeds.
Of the paper mulch trials distributed over the state, positive
stimulation of plant growth and yields were obtained with the
following crops: Potatoes at Hastings, carrots and beets at the
Main Experiment Station farm, and corn at LaCrosse. Those
with reduced growth effects were: Cabbage and carrots at the
Everglades Experiment Station, strawberries at Plant City, pep-
pers and cucumbers at LaCrosse, watermelons and cantaloupes
at the Main Experiment Station farm and at O'Brien, respective-
ly. Crops affected neither way: Beans (mulch paper hastened
maturity slightly) and tomatoes at LaCrosse; onions, lima beans
and English peas at the Main Experiment Station farm.
The soil temperature curve under mulch paper fluctuates less
than the temperature of unmulched soil. At nights the tem-
perature of the papered soil is from 5 to 10 degrees higher than
of the unpapered soil and in the daytime from 5 to 10 degrees
lower under papered soil than unpapered soil.
Soil moisture ranges from 1 to 2.5 percent greater under
papered soil than unpapered soil, depending on recent precipita-
tion.
Avaliable soil nitrogen is from 1.5 to 2 parts per million
greater under papered soil than unpapered soil.
Paper mulch will keep weeds suppressed so long as it remains
over the soil.
Experiments are being conducted at LaCrosse on the rela-
tion of mulch paper to the rate of fertilizer application and the
relative effects of white and black papers upon plant growth and
yields. Sweet potatoes are being used for these studies. Tem-
perature relations of white and black papers are being recorded,
also determination of soil moisture, available soil nitrogen and
pH values of papered and unpapered conditions are being con-
tinued.





Florida Agricultual.Experiment Station


PLANT PATHOLOGY

Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Plant Pathology for the fiscal year ending June 30, 1930.
Respectfully submitted,
W. B. TISDALE,
Plant Pathologist.


On the whole, the work of the department has progressed
in a satisfactory manner. There was some interruption of the
work on certain projects on account of three members of the
department being detailed on other duties for a part of the year,
and because several new men were started in at different times.
The head of the department spent most of the first two months
of the year at the Tobacco Experiment Station taking care of
the variety and strain tests of tobacco for resistance to black-
shank. D. G. A. Kelbert was detailed to the State Plant Board
on work in connection with eradication of the Mediterranean
fruit fly until December 1, 1929, and Erdman West continued
with that organization until April 1, 1930.
Reports from growers and county agents, supplemented by
observations of various members of the staff, indicate that losses
of most crops due to disease have been less this year than here-
tofore. Outstanding examples of improvement in this respect
are cabbage, celery, tomatoes, potatoes, beans, strawberries, and
tobacco. This indicates that the growers have put into practice
the information obtained by members of the staff and made
available through station publications.
The volume of correspondence during the year is further in-
dication that there is a growing interest among the farmers for
improving the yield and quality of their crops by preventing
plant diseases. All told, members of the department at Gaines-
ville have written approximately 2,000 letters, giving requested
information on identifying and controlling diseases. Further-
more, considerable time has been devoted to identifying plant
diseases for the Plant Board.
In addition to this kind of work many trips have been made
into the field for studying diseases and to advise farmers and
county agents on methods of control. Assistance has also been






Annual Report, 1980


given by members of the department in programs for county
agents and Farmers' and Fruit Growers' Week.
The department now has 25 projects under investigation. A
few of these will be closed this year and others opened as time
for investigation permits. Several projects which had been
carried as inactive for several years were dropped from the list.
This was done because most of the projects were relatively un-
important or because of insufficient funds to employ extra men
to undertake the work. Certain changes have been made in pro-
ject assignments and the project leaders have been provided
with modern apparatus, so far as funds would permit, in order
to expedite the work.
The 1929 Legislature provided funds for investigating dis-
eases of watermelons and ornamentals. Two men have been
employed and assigned to these projects with Leesburg as head-
quarters. A laboratory building and greenhouse have been con-
structed on a lot donated by citizens of Lake County. The lab-
oratory has been equipped and is now in use.
Cooperative investigations have been continued with the State
Plant Board in studies of citrus canker and with the Office of
Horticultural Crops and Diseases, United States Department
of Agriculture, and the Department of Chemistry of the Florida
Agricultural Experiment Station in the investigation of nail-
head rust of tomatoes. Further cooperation has been main-
tained with the Office of Horticultural Crops and Diseases in
that facilities in the Bradenton laboratory have been extended
to Dr. S. P. Doolittle during the winter months for his work on
virus diseases of truck crops, especially tomatoes and celery.
Numerous specimens, both phanerogamic and cryptogamic,
have been added to the herbarium during the year. The phan-
erogamic specimens consist of about 1,000 sheets of mounted
specimens of Florida flowering plants and 100 sheets of Wyo-
ming plants, which were donated by Miss Lillian E. Arnold.
About 200 specimens of cryptogamic plants have been collected
and identified by the mycologist and added to the herbarium. A
few other specimens have been obtained by exchange.
The reports of progress on the different projects are given
separately under the project numbers and are included herewith.






Florida Agricultual Experiment Station


GUMMING OF CITRUS
(Adams Project No. 1)
The work on this project during the past fiscal year was con-
fined largely to following up the studies started in four groves
in the vicinity of Cocoa during the fiscal year 1926-27 to de-
termine the possibilities of curing trees affected by these de-
structive bark diseases. The method of treatment used was
scraping off the outer bark, not only all the lesions but also well
in advance of them, and applying a disinfectant paste or wash.
During the succeeding year a block containing 70 trees affected
by these bark diseases in another grove was included in this
study. With the exception of 73 trees in one grove which were
not examined during the year 1927-28, these trees have been in-
spected each year and retreated in all cases where the disease
has continued its development or where new infections occurred.
In some cases trees that did not require any retreatment one
year required it subsequently.
The 374 citrus trees under observation during the fiscal year
ending June 30, 1929 have again been inspected and retreated
where necessary. These comprised chiefly grapefruit, orange
and tangerine trees. Of these trees, 27 were removed or dis-
carded on account of decline from gummosis or psorosis and 18
on account of decline from other causes, chiefly blight. In this
connection, it should be borne in mind that a good many of the
trees exhibited late stages of psorosis or gummosis when the
study was begun. Of the trees remaining alive and worthy of
further consideration, 123 required additional treatment because
the disease was not checked by previous treatments, 56 were all
right where the disease was previously treated but required re-
treatment because of new infections at other points, and 150
apparently were all right and exhibited no need of further treat-
ment.
This study shows that infections of relatively recent origin
were readily cured in most cases by a single treatment, but that
lesions, especially where of several years' standing, were very
difficult and often impossible to cure before the trees became
seriously affected, although the progress of the disease was con-
siderably retarded in some cases. Both gummosis and psorosis
are very likely to continue their development where a very
thorough job of bark scraping has not been done and gummosis
is especially apt to break out at points at some distance above






Annual Report, 1930


the treated area, even when the progress of the disease at the
treated place appears to have been arrested. In the case of pso-
rosis, especially on tangerine trees, while the disease was arrest-
ed in a great many cases at the treated places, new infections de-
veloped at other points. A study of the respective organisms
responsible for psorosis and gummosis, and of the extent to
which secondary organisms appear to aggravate the bark kill-
ing initiated by these diseases in many cases obviously is re-
quired before marked progress can be made in our knowledge
of these pernicious bark diseases. Observations on the bark
scaling and exfoliation of the superficial corky layers on the
scraped areas of bark show that there are consistent differences
in the reactions of grapefruit, orange, and tangerine trees. The
bark scaling is thickest and exfoliation slowest on grapefruit
trees and the scaling thinnest and exfoliation most rapid on tan-
gerine trees. Orange trees occupy a position in this respect in-
termediate between grapefruit and tangerine trees.

MELANOSE AND STEM-END ROT OF CITRUS
(Adams Project No. 3)
The only work done on this project was a continuation of the
cooperative agreement entered into several years ago between
the department and the Atwood Groves, Inc., at Palmetto. Ac-
cording to the agreement, the company sprayed the grove for
commercial control of the disease, but failed to leave any trees
unsprayed for check. Also on account of favorable results ob-
tained last year, they used only one spray material-bordeaux-
oil (Volck)-and made two applications of this.
Observations were made in the grove on the results obtained
by D. G. A. Kelbert. The data obtained are as follows:
Percentage of bright and melanose infected grapefruit in At-
wood Grove, which was sprayed twice with bordeaux-oil (Volck).
Total Fruit Percent Percent Percent injury from
Counted Brights Melanose Other Causes*
2,129 35 14 51
*Rust mite, thrips, wind, spray burn, and scab.
It was observed that melanose was quite general on leaves of
late flush of growth in 1929. Stem infection was limited to
water sprouts and these were not abundant in the grove.
Scab infection was limited to two trees and these were only
slightly infected.
There was also excellent control of scale-insects.






Florida Agricultual Experimenet Station


CITRUS CANKER
(Adams Project No. 11)
Due to the curtailment of grove inspection for citrus canker
during most of the past year, very few (4) determinations for
citrus canker have been made.
The following experiments have been completed with sufficient
data to warrant the following summaries:
1. A saturated solution of potassium permanganate used in
a strength of 1-100 killed cultures of Phytomonas citri in 21'
minutes, but a strength of 1-1,000 did not kill in 25 minutes.
2. When the following were added to sterilized sandy soil
which had been inoculated with P. citri they were effective
against P. citri as indicated:
a. Potassium permanganate in quantities of 1 part saturated
solution to 50 parts of soil moisture failed to kill the organism
in 18 days.
b. Acetic acid added in quantities of 1 part molar solution
to 4 parts of soil moisture killed the organisms in 24 hours, but
strengths of 3 to 80 did not kill in 14 days.
c. Formaldehyde added in quantities of 1 part commercial
strength to 160 parts of soil moisture killed P. citri in 24 hours.
Sixty-one members of the RUTACEAE family have been
inoculated with P. citri. All developed lesions. The following
have not been reported by previous workers:
CPB No. Name
10161 Citrus inodora
48010 AH. Thomasville citrangequat
11398 Williams tangelo
10280 Citrus sp.
10372 Citrus sp.
7725 Balsamocitrus paniculata
7294 Feronia lucida
11432 Feroniella obligata
2916 Severinia buxifolia
11667 Severinia buxifolia
Citrus myrtifolia
P. citri lived 150 days, but not 200 days, in sterile muck soil.
P. citri desiccated under the indicated conditions were found
to live as follows:
1. P. citri from potato broth cultures dried on glass was able
to live for 27 days.
2. P. citri obtained directly from the host plant tissue and
dried on glass was able to live for 121 days; its pathogenicity
was slightly impaired after 30 days.





Annual Report, 1930


3. P. citri in the host plant tissue as for herbarium specimens
dried on glass lived for 15 days, but was dead within 30 days.
The following experiments are in progress:
A further study of the disinfecting value of acetic acid for
eradicating P. citri from the soil. Tests of various rutaceous and
non-rutaceous plants as harborers of P. citri, which might be-
come foci for reinfection. Several of the plants have been found
to carry the organism in a viable condition for some time, al-
though no lesions are found.
1. In this connection the following non-rutaceous plants have
been inoculated with P. citri:
Melia azadarach Codiaeum variegatum
Swieteuia mahagoni Bursera simarubra
Ilex cassine Pithecolobium Unguis-Cati
Asiminia reticulata Randia aculeata
Aralia spinosa Baccharis halmifolia
Psidium guiajava Brassica oleracea
CITRUS BLIGHT OR CHRONIC WILT
(State Project No. 32)
Active work on this project has been largely abandoned since
it has been fairly conclusively demonstrated that this chronic
wilting and decline of citrus trees is caused largely by both
deficits and excesses of soil moisture or combinations of these
extremes. Moreover, there seems to be no remedy after the
trees once start to develop this trouble. Although of relatively
rare or infrequent occurrence throughout the majority of the
state, especially where rough lemon rootstock is used, this
trouble still constitutes a source of great loss and concern to
growers in Brevard County, many of whom continue to take out
large numbers of their older trees each year. The experimental
plantings of trees budded from various typically blighted trees
are still being maintained and call for a certain amount of at-
tention from time to time. In general, they are doing as well as
could be expected of any trees under like circumstances. Many
of these trees were budded six years ago and show no evidence
whatsoever that the trouble known as blight which was formerly
considered to be a contagious disease, can be transmitted by
budding or grafting. The numerous trees budded or grafted
from blighted trees have in all cases made a development fully
comparable to those budded or grafted with budwood obtained
from the best of trees and have borne fruit for the past three
years. Additional observations and photographic records are
being continued from time to time as opportunity presents itself.





Florida Agricultual Experiment Station


DISEASES OF CITRUS APHIDS
(State Project No. 114)
The field studies of the past four years show a definite cycle
of progressions throughout each year. With minor variations
this cycle repeats itself each year. With regard to Empusa fre-
seni Nowak, the cardinal points thus far determined by labora-
tory and field studies are: Overwintering of the fungus may
occur in the groves in Florida by either of two ways. (1). The
development of the zygospores of the fungus during October
and November may occur in some abundance each year. Or (2)
the fungus may live over the winter in its active stages in the
active colonies of aphids. The occurrence of the disease in the
spring is concurrent with the abundance of overwintering ma-
terials, and the abundance and the activities of the aphids. Epi-
demic killings of the aphids on citrus are to be expected only
with the re-migration of these insects. This is induced by scarc-
ity of feeding materials for the aphids, which has occurred on
citrus during late April or early May. Dissemination of the
fungus over long distances is brought about through the agency
of the migrating forms of the three most commonly found forms
of aphids on citrus.
From the field studies the practical applications in grove and
citrus operations for aphid control are evident in the following
three points. Contact insecticides in the control may be limited
to March or early April. Young plantings and especially new
plantings of citrus may be aided in natural control of aphids by
intercropping with melons. In old groves some care in the
handling of the watersprouts in the fall and winter may con-
serve the resting spore stage of the fungus and aid in the initia-
tion of the disease in the spring.
The field phases of this problem are being prepared for pub-
lication at this time. The detailed life-cycle and developmental
studies as found in the aphids are lacking in certain convincing
data and evidence in some of the cardinal points. It is hoped
that one or two of these points may be cleared up before the pub-
lication of this part of the investigations is attempted.





Annual Report, 1930


CITRUS SCAB AND ITS CONTROL
(Hatch Project No. 24)
The only work done on this project was to test a new fungi-
cide, Cal-mo-sul, for control of the disease.
Sour orange trees in the grove on the Experiment Station
grounds at Gainesville were used in the experiment. The first
application was made after about three fourths of the blossoms
had shed and two others were made on part of the trees at in-
tervals of 25 days. Thus, part of the trees received no treat-
ment (checks), part received one treatment, part two and part
three treatments.
Observations made on June 27 showed no difference in per-
cent or degree of infection on the sprayed and unsprayed trees.
All had severe scab infection.

DOWNY MILDEW OF CUCURBITS
(Adams Project No. 19)
The application of fungicides for the control of downy mil-
dew, Pseudoperonospora cubensis, has been advocated for some
time. The question has been raised however as to the advisabil-
ity of such treatment in Florida, because the sprays reduce the
yield of early fruit which is the most profitable.
Consequently, experiments were planned and conducted dur-
ing the past year in which a hundred cucumber plants were
grown. Half of them were sprayed with 4-4-50 bordeaux mix-
ture, while the remaining plants were not sprayed and were used
as check plants. The blossoms of the plants were counted daily
with definite account made of pistillate and staminate flowers.
The fruit was picked from the plants as soon as it was definitely
known to have begun growth following fertilization.
The data have been secured and tabulated. It will require
several seasons' data before conclusions will be drawn. The work
will be continued another season in much the same way as con-
ducted this year.

CONTROL OF DOWNY MILDEW ON CUCURBITS AND
OTHER HOST PLANTS
(Hatch Project No. 30)
The field work of this project was conducted in a manner sim-
ilar to the work of the previous season. Approximately four
and one half acres of cucumbers in four widely separated plots





Florida Agricultual Experiment Station


were sprayed and dusted with several kinds of fungicides. Those
used were sulphur, copper-lime dust, copper carbonate dust,
copper stearate dust, and bordeaux mixture. The applications
were made weekly. The yields noted from the various plots
during the season were compared with the yields obtained from
the check plots to which no fungicides were added.
The best control of the disease was obtained on plots which
were treated with the copper fungicides. The plots treated with
sulphur were no better than the check plots under most favor-
able conditions and they were often much worse. The copper
dusts were as good as the liquid spray in most of the plots. Cop-
per stearate and copper-lime dust were probably the best fungi-
cides when appearance of vines and fruit are taken into con-
sideration along with the total yield. These general conclusions
have been reached from the data collected from the experimental
plots during the past season.
This project has been conducted during the past five years and
it is recommended that it be discontinued with this year's work,
since the results coincide so closely with previous data that con-
clusions reached from the accumulated data will be correct.

NAILHEAD SPOT OF TOMATOES
(Hatch Project No. 115)
The application of fungicides in dust and liquid form for the
control of nailhead spot, Macrosporium tomato, of tomato was
continued the same as last year. About 16 acres of tomatoes
were used in the experiments. Certain beneficial effects on the
foliage as the result of spraying and dusting were noted. Other-
wise very little information was gained, since the disease did not
develop in any of the tomato-growing sections. The only ex-
planation offered is that the general planting of the Marglobe
tomato, which was found in early experiments conducted in
Florida by the Florida Agricultural Experiment Station to be
more or less resistant to the nailhead disease, has gradually elim-
inated the trouble.
The selection and propagation of tomatoes showing desirable
qualities has also been conducted at the Manatee County labora-
tory where variety plots have been grown in cooperation with
the Office of Horticultural Crops and Diseases of the United
States Department of Agriculture.
It is recommended that this project be discontinued with this




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