Front Cover
 Title Page
 Table of Contents
 Letter of transmittal
 Report of director
 Report of business manager
 Animal industry
 Cotton investigations
 Plant pathology
 Agricultural economics
 Home economics
 The tobacco experiment station
 The citrus experiment station
 Everglades experiment station

Report for the fiscal year ending June 30th
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00005173/00003
 Material Information
Title: Report for the fiscal year ending June 30th
Physical Description: v. : ill. ; 23 cm.
Language: English
Creator: University of Florida -- Agricultural Experiment Station
Publisher: University of Florida
Place of Publication: Gainesville Fla
Creation Date: 1928
Publication Date: 1905-1944
Frequency: annual
Subjects / Keywords: Agriculture -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
serial   ( sobekcm )
Statement of Responsibility: Florida Agricultural Experiment Station.
Dates or Sequential Designation: 1905-1944.
 Record Information
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 002452807
oclc - 12029638
notis - AMF8112
System ID: UF00005173:00003
 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
    Title Page
        Page 1
    Table of Contents
        Page 2
    Letter of transmittal
        Page 3
        Page 4
    Report of director
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
    Report of business manager
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
    Animal industry
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
    Cotton investigations
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
    Plant pathology
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
        Page 77
        Page 78
        Page 79
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
        Page 85
    Agricultural economics
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
    Home economics
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
    The tobacco experiment station
        Page 99
        Page 100
        Page 101
        Page 102
        Page 103
    The citrus experiment station
        Page 104
        Page 105
        Page 106
        Page 107
        Page 108
        Page 109
        Page 110
    Everglades experiment station
        Page 111
        Page 112
        Page 113
        Page 114
        Page 115
        Page 116
        Page 117
        Page 118
        Page 119
        Page 120
        Page 121
        Page 122
        Page 123
        Page i
        Page ii
        Page iii
        Page iv
Full Text





JUNE 30, 1928

[ENT' .,

"i ..?

.' *'

". .i. :/ .

.... ^
/ ".. .

.* .' :

*' i '

**'''-':*.- :



JUNE 30, 1928

REPORT OF DIRECTOR .... ...........---------- ------- ---------- ------- 5R
Introduction, 5R; Changes in Staff, 6R; Project List, 8R.
REPORT OF BUSINESS MANAGER ...............--- ---------------- -------- 13R
PUBLICATIONS ..............---------------- ---. 16R
AGRONOMY -............--....--.--. ------- ---. --. --- ----- ...... 20R
Plant Introduction, 20R; Winter Legume Plants, 20R; Soybean
Variety Work, 21R; Crotalaria Studies, 21R; Pigeon Peas, 22R;
Pasture Work, 22R; Lawn.Grass Studies, 23R; Fertilizer Experi-
ments, 24R; Spacing Test with Peanuts, 24R; Oat Tests, 25R;
Time of Planting Corn, 25R; Crop Rotation 25R; Corn Fertil-
izer Studies, 26R; Cover Crop Studies, 26R; Napier Grass, 28R;
Plant Breeding, 28R; Growth Behavior of Bahia Grass, 29R; Pas-
ture Fertilization, 32R.
ANIMAL INDUSTRY -- ..-.......... .................---- -33R
CHEM ISTRY .. ----............. --..... ..-- ..... ------ .------ -----...-- -- 34R
Dieback of Citrus, 34R; Soils Studies, 34R; Nutrition Studies,
35R; Fertilizer Experiments, 36R; Miscellaneous, 37R.
COTTON INVESTIGATIONS .......... ..................... ..... .------ --.--- ----. -- 38R
Plant Pathology and Physiology, 38R; Cotton Breeding, 39R; En-
tomology, 40R.
ENTOMOLOGY ----.................. ........-... ......... ...----...--- 42R
Citrus Aphid, 42R; Fumigation of Citrus, 45R; Plant Bugs, 45R;
Red Spiders, 46R; Root-Knot, 47R; Introduction of Parasites,
47R; Thrips, 48R; Pecan Insects, 48R.
H ORTICULTURE ...............-...... ................ ......... ........... .---.... 50R
Frost Studies, 50R; Physiology of Fruit Production, 51R; Pecan
Investigations, 52R; Test Grounds, 57R; Truck Crops, 59R.
PLANT PATHOLOGY ...........................-...... .....---- ----.....------ 65R
Publications, 59R; Melanose, 66R; Citrus Canker, 67R; Truck
Crop Diseases. 67R; Mycology, 70R; Citrus Blight and Psorosis,
71R; Strawberry Diseases, 73R; Irish Potato Diseases, 74R; En-
tomogenous Fungi, 77R; Pecan Diseases, 78R.
VETERINARY ..............................-....- ....... .... -...--- ---..... .------- 79R
Manson's Eyeworm of Poultry, 79R; Kidney Worm of Swine,
81R; Poultry Diseases, 81R; "Salt Sickness", 84R; Daubentonia
Seed Poisoning in Poultry, 84R; Diagnostic Laboratory Report,
AGRICULTURAL ECONOMICS .-......-....... ......... ....................... 86R
Potato Farming Study, 86R; Cost of Picking, Hauling and Pack-
ing Citrus, 87R; Jackson County Farm Management Survey, 87R;
Citrus Transportation Cost Study, 87R; Dairy Farming Study,
89R; Miscellaneous, 89R.
HOME ECONOMICS ......- ................... -..-. ... ........ -....- ....... 91R
Vitamin A in Animal Nutrition, 91R; Nutrition Study of School
Children, 94R; Jellying of Citrus Fruits, 95R; Canning of Non-
Acid Vegetables, 96R.
LIBRARY ....................... ........ ....... ... .............. 97R
THE TOBACCO EXPERIMENT STATION ... .. ---... .................... ........ 99R
Fertilizer Experiments with Shade Tobacco, 99R; Disease Investi-
gations, 100R; Diseases Observed, 102R.
THE CITRUS EXPERIMENT STATION ...............................................104R
Nursery, 104R; Variety Grove, 104R; Bud Supply Grove, 105R;
Potash Groves, 105R; Dieback Grove, 106R; Pathological Grove,
106R; Other Groves, 107R; Citrus from Cuttings Compared with
Seedlings, 108R; New Root System, 108R; Agronomy Experi-
ments, 108R; Weather, 110R.
EVERGLADES EXPERIMENT STATION ..............................................- 111
Buildings and Improvements, 111R; Soils, 111R; Pathological
Work, 120R; Agronomy, 121R.

Hon. John W. Martin,
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 Station for the fiscal year ending June 30, 1928.
Chairman, Board of Control.

P. K. YONGE, Chairman, Pensacola E. L. WARTMANN, Citra
E. W. LANE, Jacksonville J. T. DIAMOND, Secretary, Talla.
A. H. BLANDING, Leesburg hassee.
W. B. DAVIS, Perry J. G. KELLUM, Auditor, Tallahassee
S. T. FLEMING, A.B., Asst. Director RUBY NEWHALL, Secretary
J. FRANCIS COOPER, M. S. A., Editor K. H. GRAHAM, Business Manager

W. E. STOKES, M. S., Agronomist
W. A. LEUKEL, Ph. D., Asso.
C. R. ENLOW, M. S. A., Asst.*
FRED H. HULL, M. S. A., Asst.
A. S. LAIRD, M. S. A., Asst.
A. L. SHEALY, D.V.M., Veterinarian,
in Charge
D. A. SANDERS, D.V.M., Asst. Vet.
E. F. THOMAS, D.V.M., Asst. Vet.
F. X. BRENNEIS, B. S. A., Asst.
Dairy Investigations

C. V. NOBLE, Ph. D., Ag. Economist
M. A. BROKER, M. S. A., Asst.
L. W. GADDUM, Ph. D., Asst.
C. F. AHMANN, Ph. D., Asst.
J. R. WATSON, A. M., Entomologist
A. N. TISSOT, M. S., Asst.
H. E. BRATLEY. M. S. A.. Asst.

R. M. BARNETTE, Ph. D., Asso. A. F. CAMP, Ph. D., Horticulturis
C. E. BELL, M. S., Asst. M. R. ENSIGN, M. S., Asst.
H. L. MARSHALL, M. S., Asst. HAROLD MOWRY, B. S. A., Asst.
J. M. COLEMAN, B. S., Asst. G. H. BLACKMON, M. S. A., P<
J. B. HESTER, B. S., Asst. Culturist
M. N. WALKER, Ph. D., Asst. G. F. WEBER, Ph. D., Asso.
E. F. GROSSMAN, M. A., Asst. K. W. LOUCKS, B. S., Asst.
RAYMOND CROWN, B.S.A., Field Asst.ERDMAN WEST, B. S., Mycologist



W. B. TISDALE, Ph. D., Plant Pathologist in Charge Tobacco Experiment
Station (Quincy)
Ross F. WADKINS, M. S., Lab. Asst. in Plant Pathology (Quincy)
JESSE REEVES, Foreman, Tobacco Experiment Station (Quincy)
J. H. JEFFERIES, Superintendent, Citrus Experiment Station (Lake Alfred)
W. A. KUNTZ, A. M., Assistant Plant Pathologist (Lake Alfred)
W. L. THOMPSON, Assistant Entomologist (Lake Alfred)
GEO. E. TEDDER, Foreman, Everglades Experiment Station (Belle Glade)
R. V. ALLISON, Ph. D., Soils Specialist (Belle Glade)
J. H. HUNTER, M. S., Assistant Agronomist (Belle Glade)
J. L. SEAL, Ph. D., Assistant Plant Pathologist (Belle Glade)
H. E. HAMMAR, M. S., Field Assistant (Belle Glade)
L. O. GRATZ, Ph. D., Associate Plant Pathologist (Hastings)
A. N. BROOKS, Ph. D., Associate Plant Pathologist (Plant City)
A. S. RHOADS, Ph. D., Associate Plant Pathologist (Cocoa)
STACY O. HAWKINS, M. A., Field Assistant in Plant Pathology (Homestead)
D. G. A. KELBERT, Field Assistant in Plant Pathology (Bradenton)
R. E. NOLEN, M. S. A., Field Assistant in Plant Pathology (Monticello)
FRED W. WALKER, Assistant Entomologist (Monticello)
E. D. BALL, Ph. D., Associate Entomologist (Sanford)

*In cooperation with U. S. Department of Agriculture.

Report for the Fiscal Year Ending

June 30, 1928

Hon. P. K. Yonge,
Chairman, Board of Control.
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, 1928; and I request that you transmit the same, in accord-
ance with law, to His Excellency, the Governor of Florida.

A summary of the activities of the various departments in the
Experiment Station and Branch Stations is given in the follow-
ing pages.
The financial resources of the Experiment Stations for the
fiscal year just closed have been as follows:

Federal Adams Fund ...........................................-- 15,000.00
Federal Hatch Fund ......................... .......................... 15,000.00
Main Station, Gainesville ............................................ 223,005.00
Citrus Station ............................................................. 15,150.00
Tobacco Station .......................... ................... ...... 15,950.00
Everglades Station ....................................................... 65,000.00
Station Incidental Fund .............................................. 19,459.43
Everglades Incidental Fund ........................................ 6,990.98
Total ..................................................................... $375,555.41
Federal Purnell Fund, not included above..................$ 40,000.00

6R Florida Agricultural Experiment Station

Dr. C. F. Ahmann was appointed Assistant in Home Econom-
ics Research July 4, 1927.
F. W. Brumley was appointed Field Assistant in Agricultural
Economics for the month of June, 1928.
Dr. O. F. Burger, Plant Pathologist, died January 26, 1928.
Dr. F. R. Darkis was appointed Assistant Chemist at Citrus
Experiment Station, effective November 1, 1927 and resigned
on February 1, 1928.
Auther H. Eddins was appointed Assistant Plant Pathologist
effective May 15, 1928.
C. R. Enlow was appointed Assistant Agronomist, September
1, 1927. (In cooperation with forage crops office, U. S. Depart-
ment of Agriculture.)
Dr. J. F. Fudge was appointed Assistant Chemist at Citrus
Experiment Station June 1, 1928.
H. E. Hammar was appointed Field Assistant, Everglades
Experiment Station, September 16, 1927 to succeed J. G. Kelley,
Fred H. Hull was appointed Assistant Agronomist, Septem-
ber 1, 1927.
A. S. Laird resigned as Assistant Agronomist on June 15,
J. Wm. Lindsey was appointed temporary Field Assistant,
Agricultural Economics, from December 15, 1927 to May 31,
Ernest G. Moore was appointed Assistant Editor, September
15, 1927.
Mrs. J. M. Morrison was appointed Housekeeper at the Ever-
glades Experiment Station June 1, 1928 to succeed Mrs. Bertha
Lockmiller, who resigned on May 31, 1928.
J. L. Seal was appointed Associate Plant Pathologist at the
Everglades Experiment Station on July 1, 1927.
John M. Scott resigned as Animal Industrialist and Vice-Di-
rector on May 15, 1928.

Annual Report, 1928 7R

Dr. A. L. Shealy was appointed Head of the Animal Husbandry
Department on May 15, 1928 to fill the vacancy caused by the
resignation of J. M. Scott, Animal Industrialist, on same date.
Charles G. Swoope was appointed temporary Assistant Chem-
ist from February 6, 1928 to April 30, 1928 substituting
for C. E. Bell while on leave of absence.
W. L. Thompson was appointed temporary Assistant Ento-
mologist, Citrus Experiment Station, on August 1, 1927 to sub-
stitute for R. L. Miller while on leave of absence.
C. B. VanCleef was appointed Greenhouse Foreman, Horticul-
tural Test Grounds, July 1, 1927 to succeed Q. E. Patton, re-
signed on same date.
Dr. E. F. Thomas was appointed Laboratory Assistant, Vet-
erinary Investigations, July 12, 1927.
H. E. Bratley was appointed Laboratory Assistant in Ento-
mology, Sept. 19, 1927.

A list of the



principal active projects carried on during the year is given below, arranged according to

Name of Project

Agricultural survey of some 500 farms in the general farming region of Northwest
A study to determine the cost of picking, hauling, and packing of Florida citrus
A study of the cost of transportation of Florida citrus fruits with comparative 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.
Peanut and corn fertilizer experiments.
Plant breeding-peanuts.
Pasture experinlents.
Lawn and golf grass studies.
Effect of land plaster or gypsum (CaSO4. 2H=0) on hay and seed production of pea-
nut varieties.
Winter legume studies.
Cover crop studies.
Crop rotation studies with corn, velvet beans, sweet potatoes and peanuts.
Variety test work with field crops.
Sources of nitrogen and rates of application of nitrogen from the different sources
as top dressing for oats.
Green manure studies.
Further studies on 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 yield.
Crop adaptation tests.
Fertilization of pasture grasses.

Project Number
New Old
103 XXVI-D
104 XXVI-E
121 XIII-D, 5
16 XIII-C 1
27 XIII-D 1
42 XIII-D, 4
43 XIII-C 2
54 XIII-E, 1
56 XIII-A, 2
97 None

98 XIII-E, 2
99 XIII-D, 3
100 XIII-D, 2
106 None
107 XIII-A, 1
120 XIII-D, 5



Name of Project

Comparison of home-grown and purchased feedstuffs for economical pork production.
A comparison of home-grown and purchased feedstuffs for economical milk production.
Types of hemorrhagic septicemia found in Florida.
"Leeches" of horses.
Use of chlorine gas in treatment of infectious mastitis in cattle.
Manson's eye worm of poultry, (Oxyspirura mansoni).
Salt sickness in cattle.
Kidney worms in swine (Stephanurus dentatus)
Test of high protein in the growth, development and production of dairy calves,
heifers, and cows.
Paralysis of domestic fowl.

Dieback of citrus.
Determination of the effect of varying amounts of potash on the composition and
yield and quality of the crop.
Determination of the fertilizer requirements of Satsuma oranges.
Determination of the effect of various potash carriers on growth, yield and composi-
tion of crops.
Determination of the mineral constituents of various Florida-grown cattle feeds, as
compared with feeds grown farther north.
Determination of the need for manure in growing shade tobacco.
Determination of the effect of various carriers of phosphoric acid on the growth and
quality of shade tobacco.
Determination of the effect of various carriers of potash on growth and quality of
shade tobacco.
Study of fertilizer requirements of citrus trees when grown on muck soil.

Composition of crops as influenced by fertilization and soil types-pecans.
Determination of fertilizer requirements of blueberry. (Inactive.)
To determine the cause of poor crop growth due to liming sandy soils.
Effect of various fertilizer formulas.
Concentrated fertilizer studies.
Determination of the effect of green manures on composition of soil.
Effect of various fertilizer treatments and of soil amendments on tomatoes.

Project Number
New Old
10 XI-C
109 XI-D

119 XXII-G
21 V
22 IX-B

36 IX-C
37 IX-D
38 XV


66 XX-A, 2
67 XX-B
68 IX-E
94 XX-A, 3
95 XX-A, 1
96 XXX
112 IX-F

Name of Project

CITRUS EXPERI- Citrus progeny and bud selection.
MENT STATION Propagation experiments with citrus plants of various kinds.
Testing of introduced and new varieties and hybrids of citrus and near-citrus.
Cover crop and green manure studies in citrus groves.
Citrus variety tests, including root stocks.




Variety testing and breeding.
Field tests with cotton. Spacing and time of planting tests.
Control of cotton insects.
Cotton physiology. Cotton rust.
Cotton diseases. Seedling diseases.
Cotton diseases. Cotton wilt.
Cotton physiology. Nutrition and growth.
Genetics of cotton. Studies in inheritance of cotton.

Velvet bean insects-life history studies of the velvet bean caterpillar.
The Florida flower thrips.
Root-knot investigations.
Introduction and study of beneficial insects.
The larger plant bugs on citrus, pecan, and truck crops.
Studies of the bean jassid.
The green citrus aphis (Aphis pomi).
Control of fruit and nut crop insects, insects affecting pecan trees.
Life history studies of Pycnoscelus surinamensis L., the roach which is the inter-
mediate host of Manson's eye worm.

Forage, truck and field crop trials.
Fruit and forest tree trials.
Field fertilizer experiments.
Insect pests and plant diseases and their control.
Soil investigations.
Drainage studies.
Soils and crop studies, including rotation, fertilizer and cultural practice experiments.

New Old
Project Number

57 XXI-C, 1
74 XXI-E
75 XXI-D
76 XXI-B, 1
77 XXI-A, 2
78 XXI-A, 1
79 XXI-B, 2
101 XXI-C, 2

7 III-A, Minor
8 III-B, Major
12 III-C, Major
14 III-D, Major
28 III-B, Minor
60 III-A, Major

84 XXV-A
85 XXV-B
86 XXV-C
87 XXV-F
88 XXV-E
89 XXV-D
90 XXV-G


Name of Project

Determination and identification of the organisms which cause the spoilage of canned
vegetables in the South.
Determination of whether chlorophyll, chlorophyll alpha and beta, the petroleum-
ether extracts of the yellow pigments of alfalfa, can be used as a source of
vitamin A in animal nutrition.
Study of the factors affecting the jellying of citrus fruits, loquats, roselle and guava.

A study to determine the apparent prevalence of nutritional diseases in rural school
children between the ages of six and twelve years in five representative coun-
ties of Florida.

Field studies of the diseases affecting the pecan, including control measures.
Field study of the insects attacking the pecan, including control measures.
Compilation of available information upon the varieties best suited to different lo-
calities and soil types in Florida and collecting information as to the best proven
methods of fertilizing, propagating and growing pecans.
Cooperative fertilizer tests in pecan orchards.
Variety and stock tests of pecan and walnut trees.
Variety test of grapes.
Propagation, planting and fertilizing tests with tung-oil trees.
Observation and testing of various citrus hybrids.
Testing of native and introduced shrubs and ornamentals and methods for their
Variety, propagation, and planting of pear, avocado, Japanese persimmon, fig, and
other fruits.
Variety tests of berries, Rnbus sp.
Cooperative cover crop tests in pecan orchards.
Tests of different stocks as root stocks for the Satsuma orange.
Phenological studies on truck crops in Florida.
Fundamental physiology of fruit production.

44 XIX-E
45 XIX-D
46 XIX-A

47 XIX-C
48 XIX-B
49 XIV-D
50 XIV-A
51 XIV-C
52 XIV-B

58 XIV-G

59 XIV-F
80 XIX-F
81 XIV-E

Project Number
New Old




Name of Project



Gumming of citrus.
Anthracnose of citrus fruits.
Melanose and stem-end rot of citrus.
Diseases of pecan trees-a study of pecan scab.
Bacterial diseases of Solanaceous plants in Florida (a) Bacterial blight caused by
B. solanacearum E. F. S.
(b) Bacterial blister caused by B. vesicatorium Doidge.
Seedbed diseases of lettuce, celery, eggplant and tomato.
Citrus canker.
Phomopsis of eggplant.
Avocado scab (inactive project).

Fruit spotting of avocados.
The downy mildew of cucurbits.
Bacterial diseases of cucurbits.
(1) Angular leaf spot and fruit rot of cucumber caused by Bacterium lachry-
mans E. F. S. & Bry.
(2) Bacterial wilt caused by Bacillus tracheiphilus E. F. S.
Citrus scab.
Citrus canker.
Control of downy mildew on cucurbits and other host plants.
Potato diseases, including potato wilt and late blight.
Citrus blight.
Diseases of strawberries.
Diseases of citrus aphis.
Nailhead rust of tomatoes.
Nailhead rust of tomatoes.

Investigation of certain diseases of corn in Florida:
1. Seedling stalk and ear diseases caused by Fusarium sp.
2. Seedling and ear diseases caused by Diplodia sp.
3. Seedling and stalk diseases caused by Physoderma sp.
Field and laboratory studies of tobacco diseases-black shank, root-knot, wildfire,
alternaria leaf spot of flue-cured tobacco and tobacco scab.
Variety tests of tobacco and other crops.

Project Number
New Old
1 IIA Major, 1
2 IIA Minor
3 IIA Major, 2
4 IIC Major
5 IIC Minor,2

IIC Minor, 4
IIA Major, 3
IIC Minor, 1
IIB, Minor,2
IIB Minor, 1
IIB Major
IIC Minor, 3

24 VII A, 1
29 VII A, 2
30 VII B, 1
31 XVI-A, 1
32 XVI-B
113 XVI-D
114 XVI-C
115 VII B, 2
116 II C
Minor, 5



Annual Report, 1928 13R


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, 1928.
Business Manager.


State Appropriation, Biennium ..-....................................--...$223,005.00
Salaries ...................................- ----------- ----... 111,508.21
Labor .............................-.....---.. ----- --------..--- 21,134.18
Stationery and Office Supplies .......................-----............ 2,929.73
Scientific Supplies, consumable .................................. 4,764.46
Feeding Stuffs ........-........--.---- .. .................. ---3,687.36
Sundry Supplies ................................... ............. 4,191.07
Fertilizers ...............-- ...-------........................... 3,766.31
Communication Service ...............................-----....... .. 2,042.04
Travel Expense ......................................-----......... 14,266.35
Transportation of Things .... ---................................. .. 1,663.09
Publications .----.....................---...............---- ...... 5,538.29
Heat, Light, W ater, Power ...................................... .. 2,496.62
Furniture, Furnishings and Fixtures ........................ 6,325.82
Library .................. ............................................. ...... 4,177.88
Scientific Equipment ............................... ......... .... 3,628.36
Livestock ................ ............. ........... ... ... ----266.55
Tools, Machinery .-...-- .....-------------------........ 5,097.01
Buildings and Land ..-...----..-..-..........---.---.- 11,107.81
Contingent ........ ...................................... 422.76
Balance ....--... ....... ---.........-- ......-- ..-........... ............... 13,991.10

Florida Agricultural Experiment Station


Balance, 1926-1927 ..................... ........ ..
Receipts, 1927-1928 .... ..... --... -.. ---

Labor ....................... -............ ----.-- -
Stationery and Office Supplies ...-.............
Scientific Supplies, consumable ..................
Feeding Stuffs .-..--------- ...
Sundry Supplies ..-...-.....-...............-. ...
F ertilizers ...............- ----------- -----... .---
Communication Service ........................~.....-....-
Travel Expense ................... ..........-.. .. ..
Transportation of Things ............... ..........
Heat, Light, Water, Power .....................-
Furniture, Furnishings and Fixtures .........
L library ....... .- -- ..-. .......-- ..- .-... .....
Scientific Equipment ....-..-- ....-- ...... ...
L ivestock --- ------- --...... ..... .-.-..---- ---
Tools, Machinery .....- ..-...--.. -----
Buildings and Land -. ...- --. ..- .....-- .....
Contingent ............-...- ..----- ....-- .....
B balance ............. -- ..- ... ..--- .....

................ .. ..... $ 3,337.56
... .......... ... 16,121.87

$ 19,459.43

-..---...... $ 3,766.38
...--..-. .. 186.48
..... ... 141.46
--------.. 5,046.34
-.. ...... 772.57
----------- 228.24
-.....--. .. 39.72
-. -...... 303.82
.- ..... 241.98
-.......-- 202.32
.. ......- 31.50
.. ..... 3.00
.. ..- ..- 15.00
-.. ...... 468.20
.......-.. 3,065.30
....... 112.02
....- ....- 3,928.20

$ 19,459.43



State Appropriation 1927-28, BIennium

..-$ 15,150.00

Salaries ........- ...- ......... ...............$ 3,496.67
Labor ..... ........-. .......- ......... ......... 2,156.02
Stationery and Office Supplies .............-................ .. 44.49
Scientific Supplies, consumable ........................... 630.84
Feeding Stuffs .................. ......-- .. ........ ......... 431.18
Sundry Supplies ..... ............. ............................ 277.84
Fertilizers .................... -. ...-- .... ........ 599.57
Communication Service ......... --.................. ... ..... 33.75
Travel Expense ..... ...... ........ ..... ............. ..- 159.10
Transportation of Things ..... .... ....... .......... 197.90
Heat, Light, Water, Power ...-...... ...-......... .... 409.38
Furniture, Furnishings and Fixtures ....................... 303.40
Library ......................... .......... .... ........ .......... 30.12
Scientific Equipment ........................ ..-...-... 644.50
Livestock ....----... .....----..~.......... ..... ........ 150.00
Tools, Machinery ............. ................. .............. 613.72
Buildings and Land ---............... ..................... 1,607.97
Contingent ---....... -.... ...- .......- .. ............. 22.25
Balance ..............---- ......-...- ..... .. ................ 3,241.30

$ 15,150.00


Annual Report, 1928


State Appropriation 1927-28, 1/ Biennium ..................................S 15,950.00

Salaries ............ ..... -..... --- --- --
L abor .. ....-- .. .... ............ .... ...-- ---
Stationery and Office Supplies ...............
Scientific Supplies, consumable ...............
Feeding Stuffs ........... ............. ..............
Sundry Supplies .... ......... ............ .......
F ertilizers .... ..--... ........ ... ----- -- ------- ------. .
Communication Service ....................... .....
Travel Expense ................ ....--.. .... .... ..
Transportation of Things .........................
Heat, Light, Water, Power ........ ........
Furniture, Furnishings and Fixtures ........
L library .............. .......-- .. .........-- ..--
Scientific Equipment ............-..-........
Tools, M achinery ...........- ...--- ........
Buildings and Land ...................... ......
Contingent ............... .. -- .. ..- .....- ......
B balance .............- .......- ----- .... .

...-...--..-- $ 8,750.00
--------... 2,483.81
...-.-. 74.81
-..-.. ... 82.05
... .. .. 119.16
.... ... 637.80
----..-.. .... 641.18
............. 33.86
............. 389.96
.......- .... 127.70
-....-..... 355.05
....- ........ 408.91
-.. ..... 80.05
.-.. ..... 235.43
..-..- ... 182.37
-.....-. 1,015.36
--.-.- ... 6.50
-. ..-..... 326.00

8 15,950.00

State Appropriation 1927-28, 1/ Biennium ............... ..................S 60,
State Appropriation, continuing ... ......... .................... ...... 5,


Salaries .... ....... .. -- .. ...........-
L ab or ........... ..... ...... ...- ..- ..... ..... ..--.
Stationery and Office Supplies .........
Scientific Supplies, consumable ............
Feeding Stuffs ... .................... .......
Sundry Supplies ........... ..... ..--.. ...
F ertilizers ............ ... .. ..... ...-- ....--.
Communication Service ...................-
Travel Expense ....................................
Transportation of Things ...............
Heat, Light, Water, Power ..........-...
Furniture, Furnishings and Fixtures .
Library ................ ...- .... .. ..-. .............
Scientific Equipment ..........................
Tools, Machinery ..................
Buildings and Land .---..-. ......
Contingent ...........................................
Balance ......-------......-------.................

S 65,



...S. 16,190.84
..... 12,110.80
.. 1,688.53
.. 507.46
.... 172.64
... 20,292.91

....-....-...- ...-.. 130.63
.. ............... 1,014.92

B balance 1926-27 ............... ... ............ ..... .... ... ............. ....
Library .............. -... .......... ........... .................... $ 21.50
Balance .----....... ... ............ ......... 6,969.48

$ 65,000.00

.$ 6,990.98

$ 6,990.98


---- ----------

Florida Agricultural Experiment Station

Wilmon Newell, Director.
SIR: I submit the following report of the Editorial and Mail-
ing Department for the fiscal year ending June 30, 1928.

More stories carrying news of the Experiment Station and
its workers, information gleaned by the workers, and hints
given by them, were prepared by the editors and published dur-
ing this fiscal year than during any previous similar period.
Suggestions on "farm work for the month" based largely on
recommendations of Station workers, were prepared each month
during the fiscal year for one Florida farm paper and for the
last seven and six months, respectively, for two others. The first
of May a farm page was started in the Sunday issue of one
daily paper, and was continued until the end of the fiscal year.
Copies of questions received by Station workers and their
answers to them were published on this page every Sunday.
Ten different stories relating exclusively to the Experiment
Station were prepared by the Editors and published in three dif-
ferent farm papers circulating in Florida. These amounted to
275 column inches of printed matter. Two stories on work of
the Station were sent to national farm journals.
The Editors devote approximately one-half of their time to
work of the Agricultural Extension Division and one-half to
work of the Station. Naturally, most of the news and informa-
tional stories sent out are considered as an extension activity,
and are not mentioned here.
The Editors have supervision of the mailing room, from which
bulletins, press bulletins, circulars, and materials and supplies
are distributed.
During the year 10 bulletins, two account books, and seven
new press bulletins were issued, while 19 press bulletins were
reprinted. Copy for these bulletins was all edited, the pictures
prepared for the engraver, bulletins turned over to the printer,
proof read, and bulletins mailed in this office.


Annual Report, 1928

A list of publications issued, with a summary of the bulletins,
No. Title Pages Edition
189 Soil Temperature Studies With Cotton-I & II..... 32 5,000
190 Stimulation of Plant Response on the Raw Peat
Soils of the Florida Everglades Through the Use
of Copper Sulphate and Other Chemicals................. 48 8,000
191 Pecan Growing in Florida ...........................- 64 12,000
192 How the Boll Weevil Ingests Poison ............... 28 3,000
193 An Economic Study of Potato Farming in the Has-
tings Area for the Crop Year 1925 ............... 104 5,000
194 Blueberry Culture in Florida ..... -....... 20 10,000
195 Diseases of Lettuce, Romaine, Escarole and Endive 36 12,000
196 Daubentonia Seed Poisoning in Poultry ........-------.. 8 8,000
197 Soil Temperature Studies With Cotton-III........ ... 32 6,000
198 Tobacco Growing in Florida ..................--.............. 56 10,000
A Method for Keeping an Account With a Crop... 5,000
A Method for Keeping an Account With a Dairy
Cow Herd --.................. ....... ......5,000

No. 189, Soil Temperature Studies With Cotton-I & II. (A.
F. Camp and M. N. Walker, pp. 32, Figs. 12.) This is a techni-
cal bulletin. The first part describes apparatus used for the con-
trol of soil temperature for experimental purposes. The second
part takes up the relation of soil temperature to the germina-
tion and growth of cotton. Experiments showed that the opti-
mum temperature for germination was around 33 or 34C. No
germination was obtained at and above 40 C or at and below
140C. It was indicated that temperature was a limiting factor
in growth only above 35C and below 200C.
No. 190, The Stimulation of Plant Response on the Raw Peat
Soils of the Florida Everglades Through the Use of Copper
Sulphate and Other Chemicals. (R. V. Allison, O. C. Bryan,
and J. H. Hunter, pp. 48, Figs. 21.) This is a preliminary re-
port of early experiments with the use of certain chemicals not
generally applied in commercial fertilizers to crops in the saw-
grass peat lands of the Everglades. Some of these chemicals,
notably copper, manganese and zinc, applied in the form of
their sulphates, gave marked positive response on plant growth.
No. 191, Pecan Growing in Florida. (G. H. Blackmon, pp. 64,
Figs. 46.) Discusses the history and development of the pecan
industry in Florida; gives hints on the selection of varieties,
the location of the orchard, nursery methods, transplanting,
and cultivation. Also tells of a method for rejuvenating neg-
lected orchards, harvesting and marketing.

Florida Agricultural Experiment Station

No. 192, How the Boll Weevil Ingests Poison. (Edgar F.
Grossman, pp. 28, Figs. 6.) This is a technical bulletin which
takes up a historic review of poisoning, and a study of the
weevil's activities. After observing characteristics of weevil
locomotion, it was believed that the weevil obtained its lethal
dose of poison by reason of the fact that poison particles adhered
to the mouth parts as the weevil crawled over the dusted plant,
and were later ingested when the weevil ate or produced man-
dibular activity. This was found to be correct. It was found
also that standard strength calcium arsenate diluted with equal
parts of lime gives good control of the weevil.
No. 193. An Economic Study of Potato Farming in the Has-
tings Area for the Crop Year 1925. (Bruce McKinley, pp. 104,
Figs. 26.) Explains the economic history and gives a descrip-
tion of the area. Analyzes the farm business from the stand-
point of tenure, utilization of farm and crop land, capital, live-
stock, farm receipts and expenses. Discusses crop practices with
potatoes, together with yields and prices obtained. Discusses
the effect of various factors on farm income.
No. 194, Blueberry Culture in Florida. (Harold Mowry and
A. F. Camp, pp. 20, Figs. 11.) Describes the species of blue-
berries being grown, telling where they are most adapted. Out-
lines soil requirement, propagation methods, cultural practices,
and harvesting methods.
No. 195, Diseases of Lettuce, Romaine, Escarole, and Endive.
(G. F. Weber and A. C. Foster, pp. 36, Figs. 19.) Describes
various diseases of these crops in detail, giving suggestions for
their control or prevention. Outlines methods of seedbed sterili-
zation and seed disinfection for the prevention of seed-borne
No. 196, Daubentonia Seed Poisoning of Poultry. (A. L.
Shealy and E. F. Thomas, pp. 8, Figs. 5.) Relates how seed of
the Daubentonia or Sesbania, a common ornamental shrub in
central and northern Florida, were found to be poisonous to
chickens, as few as nine seed in some cases causing death.
No. 197, Soil Temperature Studies With Cotton-III. (M. N.
Walker, pp. 32, Figs. 9.) Soreshin of cotton has been common in
every cotton growing state for years. In recent years it has been
found that this trouble is due to a Rhizoctonia fungus. This
technical bulletin describes work done to determine at which


Annual Report, 1928

temperatures the fungus grows best, and also pays some atten-
tion to moisture as related to the growth of the fungus.
No. 198, Tobacco Growing in Florida. (W. B. Tisdale, pp. 56,
Figs. 16.) Describes seedbed practices, setting, cultivation, cur-
ing and marketing of both bright and shade tobacco as they are
commonly found in Florida today. Gives suggestions for dis-
ease and insect control.

No. Title Author
401 Control of Root-Knot of Tobacco ............... .................W. B. Tisdale
402 Gas the Ants .........-................. -----------.... J. R. Watson
403 Purple Scale ... ........... ................. ...... J. R. W atson
404 Coccidiosis of Chickens ....-............................ -..-. --.--- .. A. L. Shealy
405 Poison the Boll Weevil Coming Out of Hibernation. _E. F. Grossman
406 Colds, Roup and Chicken Pox in Poultry.... ..... ..-..........A. L. Shealy
407 Blackhead of Turkeys --.............. ....................E. F. Thomas
Bulletin List (reprinted twice)
327 How to Poison Ants (reprint) ....................... .................J. R. W atson
331 The San Jose Scale (reprint)....................... ............... ..J. R. W atson
346 Entomogenous Fungi on Citrus (reprint)......................... J. R. Watson
348 Growing Sweet Peas in Florida (reprint) ..........................W. L. Floyd
356 Onion Thrips (reprint) .................................. ......... J. R. W atson
373 Spray Schedule for Peaches (reprint)..Carl B. James and J. R. Watson
383 Propagation of Guavas (reprint) ..............-..... ........... Harold Mowry
384 Asparagus Plumosus (reprint) .............. .. ........-- Harold Mowry
386 Papaya Culture (reprint) -..-........ .... ..........-........Harold Mowry
389 Lawns in Florida (reprint) ........ .......-................... ..W E. Stokes
392 Control of Mealy Bugs (reprint) .................... ...........J. R. Watson
394 Bulbs (reprinted twice) .......-... ..... .......................Harold Mowry
396 Blackberries and Dewberries (reprint) ..................Harold Mowry
398 Crotalaria as a Soil Builder (reprint)....W. E. Stokes and W. A. Leukel
399 Growing Annual Flowering Plants (reprint).................... W. L. Floyd
404 Coccidiosis of Chickens (reprint) .................... ...... .........A. L. Sheaiy

Florida Agricultural Experiment Station

Wilmon Newell, Director.
SIR: I submit the following report for the Department of
Agronomy for the fiscal year ending June 30, 1928.

The lawn, pasture, golf grass and forage crop investigational
work of the department has been carried on in cooperation with
the Office of Forage Crops Investigations of the Bureau of
Plant Industry of the United States Department of Agriculture,
that office having detailed a full time man, C. R. Enlow, to this
work. The Chemistry Department of the Experiment Station
has cooperated in the lawn grass, green manure, pasture and
forage crop studies. The Animal Husbandry Department of the
Experiment Station is cooperating in the carrying capacity and
forage value tests of pastures.

All work reported on in the last annual report has been con-
tinued and in many cases enlarged. Several new phases of work
have been started, such as corn breeding, oats and corn fertilizer
work and carrying capacity and forage value work with pasture
C. R. Enlow has had charge of the plant introduction work,
lawn, golf course and pasture grass studies and winter legume
and forage crop studies and the following is his report:

During the year more than 700 lots of seed and planting ma-
terial mainly of grasses, pigeon peas, Crotalarias and other le-
gumes were received from the Forage Crops Office, United
States Department of Agriculture, and other sources. The ma-
jority were small lots and were planted for observation purposes
in a new two-acre introduction garden established on the Ex-
periment Station farm.

Two combination variety and fertility tests of hairy vetch
(Vicia villosa), monantha vetch (Vicia monantha) and Austrian


Annual Report, 1928

winter peas (Pisum sativum) gave very satisfactory results on
Norfolk sand of a good grade and deep phase Norfolk sand on
which Crotalaria had been grown and turned under for four
years at the Experiment Station. Hairy vetch gave higher
yields of forage per acre than the others and the Austrian
peas outyielded monantha vetch. Monantha vetch and Austrian
peas were severely attacked by aphids late in March, but hairy
vetch alongside was not attacked. The stand of all three le-
gumes was thinned considerably in the fall and winter by root
rot (Rhizoctonia sp.). Vetches and Austrian peas failed on deep
phase Norfolk sand where summer leguminous cover crops had
not been grown and turned under.
Several cooperative tests of these winter legumes were con-
ducted in central, north and west Florida. Yields were secured
from 15 of these tests. Hairy vetch and Austrian field peas gave
excellent yields generally.
In cooperation with four other southern state experiment sta-
tions, an extensive test of monantha and hairy vetch was planted
at the Florida Experiment Station in an attempt to produce
seed. Very little seed was produced on any of the eighty-odd
plots which included rate and date of seeding, depth of plant-
ing, different rates of applying fertilizer, and with and without
a nurse crop.
Otootan and Biloxi soybeans were outstanding in forage pro-
duction among several varieties tested at the Experiment Sta-
tion during the year. Several outlying tests gave the same re-
sult. Yields were below average, due to the abnormally dry
A more extensive test of the leading varieties of soybeans
and cowpeas is being conducted this season, as well as inocula-
tion studies and a date of planting test looking toward seed pro-
duction. In the date of planting test, four varieties were planted
each month beginning March 1, last planting to be made July
1. Laredo soybeans planted March 1 matured seed by June 1
and Dixie and Mammoth Yellow shortly after, but Otootan
showed no bloom.
A detailed study of several promising species of Crotalaria
was started during the year to obtain more information on plant
habits. This includes time required on each species from emerg-


Florida Agricultural Experiment Station

ence to bloom, bloom to pod formation, pod formation to de-
hiscence, as well as observations on second crop of seed. This
work will be continued and other work on amount of seed and
plant material produced per acre is now being done.
Crotalaria striata and Crotalaria sericea continue to be the
two most promising species.


Seed were saved from several promising strains of pigeon
peas in the fall of 1927. These were planted in increase plots
and also approximately 150 additional strains are under observa-
tion during 1928. This crop has considerable promise for for-
age and green manure. It is used very extensively in Hawaii
for these purposes and the seed are used for human consumption.


In addition to work mentioned in previous annual reports,
work has been started on the possibility of increasing growth
and protein content of the most promising pasture grasses by
frequent light applications of a nitrogen fertilizer. This work
was started when 1927 results showed large increases in nitro-
gen content of pasture grasses when fertilized. The 1927 re-
sults are given in the following table:

Fertilized* and Watered

Mowed Eight Times Cut Only at

Name of Lbs. Lbs. ,% N. Lbs. Lbs.
Grass Green Dry Protein iGreen Dry

Bahia ....... 15,907 4744 2.10 622.6 22,620 8,686
Centipede .. 7,043, 2,798 1.93 337.5 12,528 5,460
Check-Not fertilized and not watered

Bahia -.- 5,934 2,0731 1.71 221.6 2,575 1,648
Carpet .... 3,389 1,257 1.56 122.6 2,506 1,203
Centipede -| 2,372 876 1.32 72.31 870 526

SEnd of Season

SN. Protein



0.84 86.5
1.02 76.7
0.77 25.3

(Analytical work by Dr. W. A. Leukel, Associate Agronomist and
Coleman, Assistant Chemist.)
*Light monthly applications of nitrogen fertilizers were applied.

J. M.


Annual Report, 1928

Results to date for 1928 on these three pasture grasses show
practically double yields of forage and a material increase in
protein content from 175 pounds ammonium sulfate per acre,
half applied April 1 and half May 1. These plots are not wa-
tered. Other phases of pasture grass investigations are reported
by the Associate Agronomist, Dr. W. A. Leukel.
During the fall of 1927, 3.5 acres of Centipede grass were set
out. This area was formerly seeded to Dallis grass in 1926, but
the land is too dry for Dallis.
Similar blocks of carpet grass, Bahia grass, bermuda grass
and a mixture of carpet, Bahia, bermuda and dallis grasses
were seeded in 1926. Steers and non-producing dairy cows are
being pastured on these plots during 1928. Some good informa-
tion on carrying capacity, rotation and fertilization is being ob-
tained. The steers are making excellent gains pastured one head
per acre.
In a test of 13 pasture grasses, 86 plots altogether, placed in
the Experiment Station pasture in 1922 and pastured continu-
ously since that date, Centipede grass has successfully crowded
out all other grasses. Centipede, while eagerly grazed by the
cattle, is rather short for grazing. Two or three selections of
this grass sent here by the Forage Crops Office have much
longer leaves and are more promising. Bahia grass, carpet, ber-
muda, dallis and centipede continue to be the outstanding pas-
ture grasses.
Work reported in previous annual reports is being continued
with St. Augustine and Centipede, outstanding as lawn grasses
at the Experiment Station.
The use of fertilizers which tend to make the soil more acid
has not controlled weeds on the Experiment Station plots. How-
ever, promising results have been obtained from the use of
a mixture of aluminum sulfate, iron sulfate and sand. This not
only destroyed the weeds but seemed beneficial to the grass.
During recent years a small black bill bug (Calendra inae-
qualis) has damaged the grasses severely by feeding on the
roots. Manila grass (Zoysia natrella) has been very badly in-
jured. These bugs were gathered by hand from the plots dur-
ing the fall of 1927. There has been no damage this spring and
summer. The few remaining bugs are destroyed as found.


Florida Agricultural Experiment Station

Forty plots of bermuda grass were seeded this spring for a
fertilizer experiment. These are fertilized with various nitro-
gen carrying fertilizers and also several complete fertilizers
are being tested.
Italian rye, red top and Kentucky bluegrass gave most prom-
ise as winter grasses for lawns. Poa bulbosa, a bulbous blue-
grass, is being tested as a permanent winter grass planted in
bermuda lawn.

The fertilizer work with Spanish peanuts in a rotation with
corn and velvet beans on Norfolk sandy land limed and unlimed
was brought to a close with the harvesting of the 1927 crop
and this experiment has been rearranged in cooperation with
the soil chemistry division of the Chemistry Department so as to
study the cause of the ill effects from the use of lime and the

The peanut fertilizer experiment was continued and as here-
tofore reported. No paying increase in yield with land plaster
alone was obtained. No fertilizer treatment increased yields
much over 100 pounds of nuts per acre. This experiment has
been further enlarged, starting with the 1928 crop, to give in-
formation on the effect of varying amounts of complete fertilizer
of two analyses, the effect of varying the analysis of a 600 pound
per acre fertilizer application and the effect of leaving the vines
on the land versus removal of the vines.
Fertilizer experimental work with Spanish peanuts near
Greenwood in Jackson County on the farm of W. B. Anderson,
Jr., in cooperation with the County Agent and A. D. Harkins of
the Greenwood Products Company, gave very small to no profit
from fertilizers. These experiments were both on Norfolk sandy
Spacing tests indicate that larger increases in yield can be ob-
tained by spacing Spanish peanuts three to four inches in the
row on two and a half to three foot rows than can be obtained
by direct application of fertilizer to the peanut crop.


Annual Report, 1928

The oat variety test was on a gravelly phase of Norfolk sandy
land on the Experiment Station farm. The following table gives
the results:

Variety Bu. per Acre

Fulghum S. C. grown seed..........................i 18.50
Coker's Pedigreed Fulghum ............................ 12.50
Appler or Hasting's 100 Bushels ................. 11.67
Texas Red Rust Proof ........................................... 8.02
B urt .......... ... .. ................ ........... ............ I 5.64

The following sources of nitrogen were tried as top-dressing
for oats, using the materials so as to furnish 15 pounds of nitro-
gen and 30 pounds of nitrogen per acre respectively; nitrate of
soda, ammonium sulfate, leunasalpeter, cottonseed meal, calurea
and calcium nitrate. When used at the rate of 15 pounds nitro-
gen (100 pounds nitrate of soda, 75 pounds ammonium sulfate,
100 pounds calcium nitrate) per acre on Norfolk sandy land,
yields were as satisfactory as where higher rates were used. The
quick acting materials gave greater increase in yield than the
slow acting cottonseed meal.

Monthly plantings of an early and a late maturing variety of
corn were made, starting in February and running through
June. This year the March planting of the late maturing variety
yielded highest.
This experiment will be continued several years so as to study
not only the effect of time of planting on the yield of corn but
the effect on interplanted cowpeas of two varieties and the ef-
fect of the last cultivation of corn on the volunteer crops and
the resultant effect of these crops on the productivity of the soil.

The crop rotation experiment has been continued with its
six-phases as outlined in the previous annual report. No out-


Florida Agricultural Experiment Station

standing results have been obtained to date, but the longer such
an experiment runs the more valuable the results become.

In addition to the regular corn rotation and fertilizer experi-
mental work which has been carried on in the past, special at-
tention is being paid to sources and rates of applying nitrogen-
ous fertilizers to corn. The materials being used are nitrate
of soda, sulfate of ammonia, calcium nitrate, calurea and leuna-
salpeter. High analysis nitrophoska, a German synthetic com-
plete fertilizer, is also being compared with standard analysis
home-mixed complete fertilizer for corn.
These corn fertilizer experiments are being carried out on
the Experiment Station farm and at four points in Alachua
County and are located on five distinct soil types.

The cover crop and green manure studies have been continued.
The Chemistry Department of the Experiment Station and J. H.
Jefferies of the Citrus Experiment Station have cooperated on
this project.
Crotalaria striata again outyielded the other leguminous
plants in the test at the Experiment Station at Gainesville and
at the Citrus Experiment Station, at Lake Alfred.
Sweet potato and corn yields were higher following Crotalaria
than following the other crops in the experiment. Crop yields
following the turning under of the Crotalaria, cowpeas, velvet
beans and beggarweed in this experiment, however, have not
been high and, in fact, as the years go by the yields seemingly
are decreasing. This is accounted for by the fact that the soil
on which this experiment is located is not naturally productive
enough to produce satisfactory crops of corn and sweet potatoes,
being high, dry, deep sandy land. Decomposition and leaching
during wet weather go on at a rapid rate and when summer
crops are turned under in winter they are largely decomposed
and the soluble decomposition products known as plant food
material are leached before the spring planted crops of corn and
sweet potatoes can make use of the material, or else the dry
nature of the soil makes it impossible for the summer crops of
corn and potatoes to take up the plant food material in time to
do these crops the most good.


Annual Report, 1928

Dr. W. A. Leukel has handled the plant physiological and
chemical phases of this project and the following is his report:
The variation in the percentage and quantity of carbohydrate
and nitrogen compounds in the Crotalaria plants at different
stages of growth was correlated with the rate of decomposition
in the soil. Plants were dug in the succulent, flowering, late
seed-pod and early winter dormant stages of growth. The plants
were separated into roots, stems and leaves and the carbohy-
drate and nitrogen compounds determined in each. Similar to
previous determinations, the stems and roots of the plants in
the early growth stages were high in percentage of total and
the water soluble forms of nitrogen and lower in percentage of
these forms of nitrogen in the later mature growth stages. The
leaves showed little variation in the percentage of these forms
of nitrogen from one growth stage to another.
Easily hydrolyzable carbohydrates were higher in the early
growth stages in the different plant parts. The leaves were
higher in starch and sugars and lower in percentage of hemi-
cellulose than the other plant parts. These compounds (carbo-
hydrates) decreased in percentage with increased vegetative
growth but became normal in the later growth stages. Cellulose
increased in percentage from one growth stage to another while
lignin remained quite constant in percentage in the later growth
stages. The leaves were low in percentage of lignin and cellu-
lose in all growth stages in comparison with the stems and
roots. Plants grown in lysimeters were cut and turned under in
the later growth stages.
A brief report on the rate of nitrate formation from these
plants when incorporated with the soil as determined by the
Soil Division of the Department of Chemistry is as follows:
The rate of nitrate formation from the leaves of these plants
was more rapid than that from the complete plant, which in turn
was much more rapid than that from the stems and roots. There
was an actual utilization of nitrates formed from the soil or-
ganic matter in the early stages of the decomposition of the
stems and roots for each growth period of the plants. There was
little or no difference in the rate of nitrate formation from the
leaves of the plants at different stages of growth. There was a
slightly more rapid nitrate formation from the complete plants
turned under in the succulent and flowering stages of growth
than in the more mature growth stages. The rate of nitrate
formation from the roots and stems of plants in the earlier


Florida Agricultural Experiment Station

growth stages was more rapid than that from similar plant
parts in the later growth stages. These observations correlate
satisfactorily with those made on the composition of the vari-
ous parts of the plants at various growth stages.
An example of this is the slow rate of nitrate formation from
the roots and stems containing high amounts of easily hydro-
lyzable carbohydrates and cellulose as compared with the com-
plete plants and the leaves. The decreased rate of nitrate forma-
tion with the roots and stems of the more mature plants is cor-
related with increased cellulose of these plant parts.

Dr. W. A. Leukel again made analytical determinations on
crowns of Napier grass from plots formerly irrigated with sew-
age and with city water and from plots receiving no irrigation.
The areas irrigated with sewage three years ago continue to
produce increased silage yields as compared with yields from
plots irrigated with city water and those which received no ir-
rigation during the same period.
Equal areas of crowns and roots and tops of these plants dug
in March, 1928, from plots previously irrigated with sewage
were over twice as great in weight as plants dug from similar
areas in plots that were irrigated previously with city water
and those that received no irrigation.
On a percentage basis the crowns of the plants in the sewage
areas were again higher in percentage of total nitrogen and
slightly higher in percentage of easily hydrolyzable carbohy-
drates. On a quantity basis comparisons are similar to those
reported for these plants in the last annual report from this
The breeding work with Spanish peanuts was continued. Bad
weather at harvest time and lack of storage facilities prevented
the saving of any considerable quantity of seed for distribution.
In addition to the selection work with Spanish peanuts, Fred
H. Hull, Assistant Agronomist, has made studies on the flower
and flowering habit of the peanut for the purpose of making
crosses. It appears now that successful crosses have been made
between several varieties of peanuts.
A few plant selections have been made in Bahia grass. These
plants differ considerably in number of branches per plant. Ap-


Annual Report, 1928

parently there are also differences between the several selections
in rate of growth and time of flowering.
Attempted crosses between different species of Crotalaria
have so far resulted in failure.

This is a new project and has as its practical object the breed-
ing of high yielding corn adapted to Florida. Several methods
of corn breeding are being studied. F. H. Hull has had charge
of this work and the following is his report.
Self-pollination was practiced in 1927 in 17 varieties of corn,
also six variety crosses, and four double crosses. Seed of the
latter were furnished by the United States Department of Agri-
culture. About five hundred self-fertilized ears were harvested
in the fall. These were subjected to a seedling and germination
test in the greenhouse during the winter. About one hundred
were saved and a short row of each planted in the field, for fur-
ther inbreeding.
Forty-two varieties and double crosses were planted in the
spring of 1928, for study and a comparative yield test. It is in-
tended that 5,000 self-pollinations shall be made in this material.
The greater number will be made in the better appearing varie-
ties. Inbreeding will be continued in the best of these new lines.
Selection will be made this fall of a number of open fertilized
ears in a good white variety and a good yellow variety. These
ears will be subjected to an ear-row test in 1929.
Instruments have been purchased for taking records of soil
and air temperature, relative humidity, rainfall and duration
of sunshine. These instruments were put in operation in the
spring of 1928 and will be kept in operation continuously.

The following phases of pasture grass work have been in
charge of Dr. W. A. Leukel and his report follows:
Studies on the growth and physiological behavior of Bahia
grass under grazed and ungrazed conditions as reported in the
annual report of 1927 are being continued. Bahia grass allowed
to grow to maturity and which received no cutting treatment
produced a more upright stem growth which resulted in poor
sod formation. Plants in the grazed area produced a horizontal
vegetative stem growth which resulted in a dense sod. The


Florida Agricultural Experiment Station

stems of the plants in the ungrazed area were heavier and were
higher in quantity of reserve organic foods as compared to
plants under grazed conditions. To determine whether the heav-
ier stems and the larger quantities of organic foods stored in
them in this area receiving no grazing or cutting treatments
for two seasons will produce a larger quantity of top growth if
cut frequently or grazed, it was given frequent cutting treat-
ments during the growing season of 1928. Another area of
Bahia grass continually grazed for several seasons was given
a like treatment. At the present writing a 45 percent increase
in top yield has been noted in favor of the grass that received
no cutting treatment or grazing the past two seasons. The stems
assumed a more horizontal vegetative growth and again formed
a dense sod. This appears to indicate that the larger quantities
of organic foods stored in these plants are again utilized for in-
creased vegetative top growth if cut frequently or grazed.
Whatever significance this has on pasture management will be
determined as this work progresses.

The studies on transplanted Bahia grass as partially reported
in the last annual report are showing significant results.
The total yield of top growth from the areas cut frequently
during the growing season was lower in grams of green and dry
weights than that from similar areas that were cut in a mature
growth state. Although the total yield of top growth from the
frequently cut plots was lower in actual weight, these cuttings
were higher in percentage of total and water-soluble forms of
nitrogen than that of the one cutting from those plots where
the grass was cut in a mature growth stage. The second top
growth in its early stages from the plots cut in a mature growth
stage was similar in composition to the top growth from the
plots cut frequently.
The stems of the plants in the frequently cut areas produced
a marked vegetative horizontal growth and covered the entire
space between the rows before the end of the growing season,
forming a dense sod. They increased in weight steadily until
September, when a slight decrease in stem weight was noted. An
increase in weight again took place during autumn and early
winter. When cut very frequently and while sufficient soil mois-
ture and soil nitrogen were available these plants produced more


Annual Report, 1928

vegetative growth than reproductive parts. Scarcity of soil
moisture and soil nitrogen during the dry part of the growing
season caused more plants in the frequently cut areas to go to
seed, but vegetative growth still appeared to predominate.
The Bahia plants in the areas that were cut in a mature
growth stage showed a greater increase in weight of stems as
the growing season advanced in comparison with those cut more
frequently. They produced less horizontal growth and made a
very poor sod. A marked decrease in stem weight was noted
late in the season after the cutting of the tops but an increase in
weight occurred again in autumn and early winter.
The roots of the plants cut in a mature growth stage showed
a greater increase in weight to a depth of eight inches than the
roots of the plants cut more frequently. A slight decrease in
root weight was noted in early fall in all plots, but an increase
took place again during early winter. This may have some sig-
nificance with reference to pasture fertilization.

Chemical analysis of the leaves, stems and roots of the plants
in the frequently and less frequently cut areas showed greater
variations on a quantitative than on a percentage basis. This ab-
sence of rapid percentage decrease in organic food reserves in
sod forming grasses given frequent cuttings may be attributed
to the growth habits of these grasses. Under grazed conditions
or when cut frequently, these plants produce a horizontal stem
growth with leaves extending horizontally and close to the
ground. Only upright leaves or stems or those high enough to
be grazed by cattle or cut by a mower are removed when the
grass is grazed or mowed. This always leaves a sufficient leaf
area on the plants under grazing conditions for photosynthetic
activity to elaborate carbohydrate food for the vegetative
growth of the plants but not greatly in excess of their growing
needs. As a result of this decreased leaf area caused by frequent
removal of the top growth a narrow carbohydrate-nitrogen ratio
was found in the respective plant parts during the greater part
of the growing season which was associated with more vegeta-
tive growth and sod formation.
The plants that were allowed to grow to maturity and were
cut in a mature growth stage were higher in quantity of organic
food reserves, due to the fact that no decrease in leaf area inter-
fered with the elaboration of such reserve foods. These plants


Florida Agricultural Experiment Station

showed a wider carbohydrate-nitrogen relation resulting from
the increased elaboration of carbohydrates over nitrogen in the
plants. This wider carbohydrate-nitrogen relation was associ-
ated with the production of more reproductive plant parts, more
upright growth of stems and leaves and less extension of sod
formation. After the removal of the mature top growth, the
aftermath in this area again showed a narrow carbohydrate-
nitrogen relation in its early growth stage similar to the top
growth of the plants cut more frequently.
A study of the variation in the percentage and quantity of
soil nitrates in these plots was correlated with the growth be-
havior of the grass. The Bahia grass in these plots is being sub-
jected to similar treatments a second season. Similar studies
are being made on Bahia grass under grazed and ungrazed con-
ditions in an open pasture. At the present writing similar dif-
ferences are noted. More definite conclusions can be made at
the end of the growing season.

To determine the effect of fertilization and irrigation on the
growth behavior and composition of pasture grasses, separate
plots of Bahia grass (Paspalum notatum), carpet grass (Axono-
pus compressus) and centipede grass (Eremochloa ophiuroides)
are being subjected to fertilization, irrigation and cutting treat-
ments. The result of these treatments on the yield, growth
behavior and composition of these grasses will be determined
at the close of the growing season.

Report of agronomy work at the branch experiment stations
will be found under the reports of these respective stations.


Annual Report, 1928

Wilmon Newell, Director.
SIR: I submit the following report for the Department of
Animal Industry for the fiscal year ending June 30, 1928.
Acting Animal Industrialist.

During the year the research work in animal industry has
consisted chiefly of a comparison of home-grown and purchased
feeds for economical milk production. Five cows have been on
Registry of Merit test and have been making satisfactory rec-
Grazing experiments are being conducted in cooperation with
the Agronomy Department. Beef and dairy cattle are being
used in these investigations. Data are being obtained on the
carrying capacity of pastures sodded to various grasses, and
records are taken relative to gains made by the beef cattle
while on these pasture plots. These experiments will necessarily
have to be carried on over a period of years before conclusive
information can be obtained, but to date the experiments show
quite clearly that good pastures can be maintained in this state,
and further, that economical gains can be obtained from beef
cattle grazed on such pasture.
Swine sanitation experiments are being conducted in connec-
tion with attempting to prevent losses in pigs caused by intes-
tinal worms. These experiments will be conducted more exten-
tively in the future.


Florida Agricultural Experiment Station


Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Chemistry for the fiscal year ending June 30, 1928.


The work on dieback has been continued as outlined in pre-
vious years. Continued studies on the reaction of soils from
healthy and dieback infected trees have shown no correlation be-
tween the pH of soils from healthy and dieback trees. Nor was
there any correlation between the water soluble solids found in
the soil from healthy and diseased trees. As stated in the last
annual report it is planned to transfer a large part of the work
on this project to the Citrus Experiment Station.
The cold weather during the winter injured the trees used
in this study at Gainesville to such an extent that no data were

The work on this project was continued along the same lines
as during the previous year. The lysimeter studies showed that
where a green manure crop is turned under and no crop grown
following this incorporation of green manure the loss of plant
food through leaching was greater than where no green man-
ure was added. Studies of soil from the green manure plots
showed that one year after a green manure crop has been added
to Norfolk sandy soils there is no appreciable increase of carbon
or humus in the soil and no increase in the amount of nitrogen.
This would indicate that the effect of plowing under a green
manure crop was lost in one year's time.
The study on the bad effect of lime on our sandy soils seems
to indicate that it is closely associated with a deficiency of avail-
able potash.


Annual Report, 1928


The high vs. low potash fertilization experiment was contin-
ued as outlined in previous annual reports (1922, p. 43R). Due
to the freeze, which destroyed most of the fruit, it was impos-
sible to carry out the experiment to determine whether varying
amounts of potash had any effect on the carrying quality of the
fruit. Likewise the freeze affected the yield to such an extent
that no conclusions could be drawn.
The two experiments located at Vero Beach on the East Coast
and at the Citrus Experiment Station at Lake Alfred comparing
the muriate, low grade sulphate and high grade sulphate of pot-
ash were continued. Up to the present no difference either in
rate of growth as measured by increase in circumference of the
trunk or in yield or quality of fruit has been found. It is be-
lieved that the results so far obtained justify the statement that
the muriate of potash can be safely substituted for the high
grade sulphate of potash for citrus at least part of the time on
the types of soil found in the Indian River section of the State.
The experiment at Lake Alfred on the typical sandy soils of the
ridge section has not as yet gone far enough to justify any state-
ment in regard to the best source of potash.
The experiments with satsumas in West Florida were con-
tinued (1923, p. 50R, 1924 p. 50R). The cold weather severely
injured a number of the trees especially at Round Lake. A crop
of fruit was harvested from the grove at Panama City. The
heaviest yield was obtained from the three plots receiving an
application of fertilizer in September.
A new fertilizer experiment with citrus on muck soils was
started west of Davie. In this experiment the effects of single
fertilizer elements as well as combinations of two or more are
being studied to determine the fertilizer needs of citrus on this
type of soil. A total of 189 trees is used in this experiment.
The concentrated fertilizer experiment in cooperation with
the U. S. D. A. at Lake Alfred was continued. The grove has
made remarkable recovery from the neglect to which it had been
subjected before the experiment was begun. As yet no differ-
ence due to the different fertilizers used has been noted.
The experiments at Lake Harris, in Lake County, have been
continued as outlined in the last annual report (P. 35R). All of
the trees made a good growth and produced a fair crop of fruit.


Florida Agricultural Experiment Station

The fertilizer experiments conducted in cooperation with the
Bureau of Chemistry and Soils, United States Department of
Agriculture, in Dade County were continued.
The results indicate that with manganese sulphate at the rate
of 50 pounds per acre applied either direct or in the fertilizer,
good crops of tomatoes can be grown without the use of stable
Lime and copper salts gave detrimental results. Everglades
muck also can be used in place of stable manure with good re-
sults. The results with the manganese iron waste obtained from
the Eastman Kodak Company were inconclusive. In one experi-
ment favorable results were obtained while in the other the re-
sults were negative.
A grant of $500 from the N. V. Potash Export My. for a
study of the effect of potash on tomatoes made it possible to
enlarge the experiments at Bradenton. The season however,
proved very unfavorable. Excessive rains flooded out part of
the field and cut down the yield on the entire experiment. Some
tests were made on the keeping quality of tomatoes from the
different plots but the result could not be correlated with the
fertilizer treatment. It is planned to repeat the experiments
this year.
All of the pecan fertilizer experiments were continued and
crops were harvested from most of the experiments. One hun-
dred and fifty three samples were taken and analyzed. No
marked differences due to fertilizer treatment were found.
A new experiment with potatoes was begun at Hastings. This
experiment seeks to determine: (1) whether all of the phos-
phoric acid and potash can be applied at one time with subse-
quent applications of ammonia; (2) whether inorganic forms
of ammonia alone can be used in place of a combination of or-
ganic and inorganic; (3) whether the new synthetic forms of
nitrogen give as good results as the older forms; (4) whether
the muriate of potash can be substituted for the sulphate of pot-
ash in potato fertilizers. The first year's results seemed to indi-
cate that some form of organic ammonia in the fertilizer gave
better crops than straight inorganic; also the muriate gave just


Annual Report, 1928

as good yields as the sulphate of potash with no appreciable
difference in the starch content of the potatoes.
The tobacco fertilizer experiments were reinaugurated under
a new shade. The plan of the experiment was altered somewhat.
In addition to a comparison of sulphate of potash with carbon-
ate of potash and manure with no manure the effects of in-
creased and decreased amount of commercial fertilizer were
studied. Up to the close of the year the season had been very
unfavorable, due to excessive rains and cold weather.

As in the past, numerous analyses of various materials were
made for other departments of the Station, principally for the
Department of Agronomy, over 300 samples of grasses being
analyzed for nitrogen for this department. A considerable num-
ber of soils were tested for acidity for farmers and the usual
number of rocks were tested for phosphate and lime.
The work of Dr. R. V. Allison at the Everglades Station has
been mainly a further study of the effect of different chemicals
not usually considered essential to plant life. Out of about a
dozen elements tested individually, compounds of copper, man-
ganese and zinc have given the best results and the further
studies largely involve the use of these elements alone and in
combination with each other and the usual fertilizer elements.
Also a study has been made of the movement of subsoil wa-
Through cooperation with the United States Department of
Agriculture a general reconnaissance of the Everglades area
was begun, in order to study and classify the various types of
peat and muck that are found in this area.
(For more detailed account of Dr. Allison's activity, see re-
port of Everglades Experiment Station.)


Florida Agricultural Experiment Station

Wilmon Newell, Director.
SIR: I submit the following report of the Department of Cot-
ton Investigations for the fiscal year ending June 30, 1928.
Associate Horticulturist in Charge.

Work was carried on in this department along the same lines
as for previous years and without any changes in personnel or
projects. Very little field work was done at Gainesville during
the 1926 season so that most of the field could be cover-cropped.
Eight acres of the Horticultural grounds were used for the cot-
ton for the Chemical Warfare Service. The Plant Board field
and a part of the general field were used for the breeding and
boll weevil work that was necessary. The work this year was
expanded in the field and numerous plantings were made in the
cotton growing counties. Bad weather conditions were unfav-
orable to cotton production but valuable results are being ob-

Besides continuing the temperature studies with cotton and
Rhizoctonia described in the report for 1926-27, some new work
has been taken up. Extensive trials of various commercial dust
treatments for seed disinfection were carried on in the hope
that some treatment would be found effective in controlling
seedling diseases. None of the 20 treatments, tried in both
greenhouse and field, showed sufficient or consistent improve-
ment over the untreated checks to warrant their use. It is be-
lieved that none of the common commercial dusts is of sufficient
value in controlling the various seedling diseases of cotton to
warrant its recommendation for further trial at the present
A survey is being made of the state to determine fairly ac-
curately the distribution and importance of the various diseases
attacking cotton in Florida. The diseases found most commonly
during the first two months of the current season were sore-
shin caused by several species of fungus parasites, particularly


Annual Report, 1928

Rhizoctonia solani Kihn; angular leaf spot caused by a bac-
terium, Pseudomonas malvacearum E. F. S.; and wilt caused by
Fusarium vasinfectum Atk. This study will be extended to a
careful survey of the fungi causing boll rots in order to de-
termine what fungi or bacteria are most important in this re-
A study of the assimilation of nitrates by cotton is being
made and particularly in regard to the effect of soil tempera-
ture upon this process. This is to be correlated with the work
on the time of application of a side-dressing. The work is be-
ing carried on in both the greenhouse and field and includes
analyses of cotton plants at different seasons and following dif-
ferent rates of application, together with studies of a similar na-
ture at various controlled soil temperatures.
A potash test has been planted in the field to determine the
effectiveness of applications of potash in reducing injury by this
disease. Work on Fusarium wilt has been continued and some
studies made on the relation of soil temperature to the develop-
ment of the disease.
It has been found that the Fusarium causing boll rots also
causes a serious damping off of cotton seedlings, as well as the
root rot of older cotton plants reported by Mrs. N. Woodruff of
the Georgia Experiment Station. A large proportion of seed-
lings brought in from the field this year showed F. moniliforme.
After isolation and series of inoculations in the laboratory it
showed a definite pathogenicity, although there was some varia-
tion in virulence of different strains. In a large number of
plantings of cotton seed this fungus showed up to only a slightly
less extent than Diplodia.

During the season of 1927 a variety test including 17 varie-
ties was conducted at Gainesville. Rhyne's Cook produced the
greatest amount of seed cotton per acre and the next five varie-
ties, in order, were Mexican Big Boll, Willis, Cook 307-6, King
29, and Express 95. In a test of seven varieties at Chattahoo-
chee, Cook 307-6 produced the highest yield of seed cotton per
acre, followed in order by Miller, Lightning Express No. 6,
Rhyne's Cook, Mexican Big Boll, Dixie Triumph, and Missis-
sippi Station Trice.


Florida Agricultural Experiment Station

During the present season (1928) variety tests are being
conducted at Gainesville on Norfolk and Gainesville soil types.
Tests are also being conducted in several localities in West Flor-
ida. Breeding work to secure better adapted strains of cotton
for Florida conditions is being continued. The varieties in
which selections are being made are Council Toole, Lightning
Express, and hybrids between Council Toole and Lightning

In addition to some 60 individual tests scattered throughout
the cotton growing area of the state, 52 1/-acre field plots, lo-
cated at Gainesville, were used for making a study of the cost
and effectiveness of early season poisoning.
Present indications substantiate the tentative conclusion, pub-
lished in the preceding annual report, that the most effective
and economical method of poisoning was to begin as soon as the
cotton first squared and to continue for about four weeks, by
which time practically all the weevils emerging from hiberna-
tion in the open have found their way to the cotton fields.
Studies of the manner in which the boll weevil ingests poison
were completed and published in Bulletin 192. Included in this
bulletin were notes on the use of syrup mixtures for mopping
and diluted calcium arsenate for dusting, with data on their
relative effectiveness. Recommendations for poisoning the boll
weevil coming out of hibernation were published in Press Bul-
letin 405.
Hibernation work on the boll weevil was continued and for the
third successive season the actual time of arrival of the hiber-
nated weevils in the fields was established by periodic examina-
tions of plants in plots exposed to infestation. The period of
heavy emergence, based on the three seasons' work, was found
to extend from late in May through June, with the heaviest
emergence occurring about June 18. This information indicates
that early season poisoning should start with the formation of
squares and continue through the month of June.
Work was continued on the study of hibernation under arti-
ficially controlled humidity and temperature conditions. In one
experiment 25 percent of the weevils survived the winter suc-
cessfully. With a little more work it is believed that conditions

Annual Report, 1928

can be determined whereby weevils can be successfully held
over for experimental work.

Studies on the biology of the boll weevil were conducted in
order to determine, (a) the effects of high and low temperature,
(b) the possibility of other foods besides cotton sustaining the
weevil and, (c) hatching and egg-laying phenomena. All of
these studies are of potential value as clues to control measures.
An intensive study is being conducted in the field to determine
which method, of a number in current usage, is best suited for
actual determination of weevil population and damage caused
in the cotton field. A simple and accurate method of determin-
ing infestation is important in both experimental work and in
practical poisoning methods.
Parasites of the boll weevil were found to be killing large
numbers of weevils and an attempt was made to determine
whether or not the parasites could be depended upon to control
the weevil. Though the parasites were found to aid consider-
ably, it was evident that they did not effect any considerable
control of the weevil.


Florida Agricultural Experiment Station

Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Entomology for the fiscal year ending June 30, 1928.

CITRUS APHID, Aphis Spiraecola Patch
As during the past two years, the investigation of the citrus
aphid was one of the major activities of the department. Ralph
L. Miller, who had charge of this work at the Lake Alfred Sta-
tion, was absent on leave for most of the year and the work
there was carried on by W. L. Thompson. The past spring was
again one of comparatively slight damage from the aphid.
This condition was again due to the character of the winter
weather which was both dry and cold, resulting in practically no
young growth on citrus trees which could furnish food for the
aphid. Consequently their numbers were so reduced that, when
growth did start in the spring, they were unable to multiply
fast enough to cause a heavy infestation, although some young
trees and tangerines were badly curled. There was a more heavy
infestation on rough lemon nursery stock and sprouts than had
been noted during previous years.
The life history studies were continued along the same lines
as heretofore. A continuous record of the generations of this
insect at Lake Alfred has been kept for two years. The severe
freeze of January 3, which destroyed all tender growth on trees
and severely damaged even mature wood, made it impossible to
continue this life history work at Gainesville during the winter.
Breeding experiments at Lake Alfred showed that the aphids
were reproducing at the usual rate, and the chief factor in pre-
venting a heavy infestation was lack of food. It was discovered
that the little young growth that does come out on the trees dur-
ing dry or cold weather does not seem to be sufficiently succu-
lent to enable aphids to thrive on it. Aphids do not flourish on
the new growth that comes out under such circumstances. They
must have not only young foliage but rapidly growing and suc-
culent foliage. This is undoubtedly the reason why they do not
attack the first flush of growth that comes out on newly planted


Annual Report, 1928

trees during the winter. This would indicate that in order to
escape aphid damage, young trees should be set out early in the
winter. Parallel life history work was carried on on both citrus
and spiraea. It was found that the growth of the aphids and
reproduction was more rapid on citrus than on spiraea, the
native host plant.
As during previous years there was no general flight of
aphids in the spring until about March 15, when the first flush
of growth began to harden a little and become unsuitable for
food. At this time the migration of aphids became general.
They appeared in considerable numbers as far north as Gaines-
ville. This agrees with previous observations, made during the
first two years of the aphid investigation, that during the spring
migration, the aphids may cover long distances, as much as
100 miles.
The study of host plants other than citrus showed more plain-
ly that, in the citrus belt, they are of very minor importance and
are to be looked upon as overflow plants to which the aphids wan-
der when they are abundant and citrus growth begins to harden.
Investigations, however, in the satsuma belt about Quincy and
Monticello showed that the wild crab apple was an important
host in this section. The crab apple drops its leaves with the
approach of cold weather. At this time eggs were laid abund-
antly on it and the aphids wintered over in the egg stage. In
this section, however, satsumas remained entirely free of infes-
tation. The failure of the insect to infest satsumas in this belt
is rather surprising, as it exists on wild crab apples and spiraea
all through this region. That it is not due to any distaste on
the part of the aphid for satsumas, is shown by the fact that
it heavily infests satsumas in the Gainesville section if the
growth is suitable. The failure may be due to the long dormant
period and the fact that the satsumas are slow to put out growth
in the spring. By the time they start the wild host plants are
in suitable condition to offer food.

The control of the citrus aphid during the winter by the lady-
beetles and syrphus fly larvae was more effective than hereto-
fore. In some groves where close watch was kept on the pro-
gress of the aphid during the winter, it was very evident that
these predators were holding down the multiplication of the
aphids. During the last two years a weekly census has been


Florida Agricultural Experiment Station

kept of the proportion of predators to aphids in the section
about Lake Alfred. A comparison of the figures for the past
winter with those of the previous one (January to March in-
clusive) showed that the predators were three times as abundant
as a year ago.
This fortunate condition of affairs was probably due to the
heavy infestation of aphids on truck crops during the early part
of the winter. Because of the drought, truck crops were unusu-
ally heavily infested with aphids during November and Decem-
ber. When these were killed by the freeze of January 3, the
predators were driven by hunger to seek other aphid colonies
and heavily parasitized the few left on citrus. This would sug-
gest that a profitable method of combatting aphids would be to
raise near citrus groves during the winter, crops which are par-
ticularly liable to be attacked by aphids, such as turnips, rape,
mustard and peas. The aphids that would attack these crops
do not molest citrus but the predators are largely the same,
although our studies show that some ladybeetles, such as the con-
vergent ladybeetles (Hippodamia convergens) seem to prefer the
garden aphid (Myzus persicae) to the citrus aphid. In general,
syrphus fly larvae have been more effective during the past
spring than ladybeetles, the reverse of conditions during other
years. Life history studies of the predators and their parasites
have been carried on as heretofore.
Efforts to establish the Chinese Ladybeetle (Leis sp.) do not
seem to have been successful, although in some cases they have
been recovered in groves several months after liberation. The
chief factor in this failure seems to be ants. They have been ob-
served to chase away the adult beetles and to kill the larvae.
Our experience during the past year has emphasized our pre-
vious conclusion that the cheapest and most effective way of
fighting the citrus aphid is through the winter cleanup. Experi-
ence again shows that if the growers will make a systematic ef-
fort to clean up the few and small colonies which occur on their
trees during winter, that the few aphids that escape or fly into
the grove will not be able to cause a general infestation before
the first flush of growth begins to harden; and that there will
be no general flight of aphids from other groves before this
time. An exception to this would be tangerines, which usually
put out their growth considerably later than other citrus and


Annual Report, 1928

are often just starting to grow when the growth on other citrus
is hardening. This results in a heavy migration of aphids to the
tangerines. Observation has shown that groves which are
planted to a single variety, or those in which different varieties
are kept separate in large blocks, suffer much less from aphids
than groves in which there is an intimate mixture of varieties.
Among new insecticides tried, a proprietary one gave a much
better kill in the open than the 3 percent nicotine sulphate-lime
dust heretofore used. The kill was quicker, therefore less inter-
fered with by wind. This is apparently a pyrethrum compound.

In cooperation with a commercial fumigation company, close
observations were made as to the comparative kill following
spraying and fumigation with hydrocyanic acid gas generated
from calcium cyanide dusted under the tents. The fumigation
was most satisfactory for the Florida red scale, a scale which is
the most difficult to kill with sprays. The kill of this insect was
higher than that of purple scale. This is due to the fact that,
unlike the purple scale, the Florida red scale seldom develops
under other scales where it is protected from the gas. The
crawlers do not exhibit such marked negative phototropism
(avoidance of light), with the result that the scales are more ex-
posed. Fumigation was less satisfactory on the pupae of white-
flies, which are always difficult to kill. It is evident that to get
an efficient kill of whitefly that have reached the pupal stage
requires a heavier concentration of the gas than is necessary for
the Florida red scale or the purple scale.


During the fall of 1927 a number of complaints were received
concerning the ravages of the plant bugs, particularly the South-
ern Green Stink bug or pumpkin bug (Nezara viridula) in
groves where Crotalaria was used as a cover crop. Investiga-
tion shows that Crotalaria is attractive to these bugs only when
it begins to form young pods or at least to bloom; and that as
long as green succulent pods remain on the plants, the bugs will
not leave it for citrus fruits, even tangerines. The few cases
of trouble observed resulted when something took the green
pods all off of the Crotalaria. This may be an early frost, drought,
or a heavy infestation of pumpkin bugs, out of proportion to the


Florida Agricultural Experiment Station

Crotalaria in the field. If the pumpkin bugs are too numerous
they may cause all the green pods to drop, whereupon they may
move on to the citrus, attacking not only the fruit but the limbs
an inch or more in diameter. In practically all cases where this
was noticed it was due to a mixture of beggarweed and Crota-
laria. A large crop of beggarweed and a comparatively small
crop of Crotalaria is undoubtedly a dangerous combination. The
stink bugs breed in large numbers in the beggarweed during
the summer and when it begins to mature and become unattrac-
tive (about October), they migrate to the Crotalaria, and if
there is little of this as compared with the beggarweed, they
may be numerous enough to cause all the pods to drop. A mix-
ture of beggarweed and Crotalaria does not, by any means, nec-
essarily mean an infestation of pumpkin bugs. Their numerous
parasites, especially the tachinid fly (Trichopoda pennipes), and
predators may control the pumpkin bugs or almost exterminate
them. The abundance of these parasites and hence the scarcity
of pumpkin bugs varied much in different vicinities studied. In
addition to the above well known parasites, an egg parasite was
found by Mr. Miller to be very effective in the neighborhood of
Lake Alfred.
These investigations indicate that Crotalaria is no more likely
to bring on an infestation of plant bugs than other cover crops;
nevertheless it is not fool-proof. The grove must be watched
and proper measures taken if pumpkin bugs appear. A sure way
to prevent injury and at the same time make use of this valu-
able cover crop is to mow the crop once or twice during the sea-
son to prevent it from going to seed in the grove. This will, of
course, necessitate growing the seed outside of the grove and
re-seeding every year. However, if the grower will give care-
ful attention to the dangers enumerated above, he can still safe-
ly allow the Crotalaria to go to seed in the grove and thus re-
seed itself.
During and following the dry weather of the early winter, red
spiders became very numerous and gave considerable trouble both
on citrus and, in one county, on Asparagus plumosus. A mixture
of sulphur and an unknown oxidizing agent supplied by a com-
mercial concern seem to give much better control than sulphur
ordinarily used for red spiders. On the asparagus, pyrethrum


Annual Report, 1928

compounds and the spray of Derrisol also gave better control
than ordinary flowers of sulphur heretofore used.

The study of the root-knot nematode (Heterodera radicicola)
was continued. As heretofore, the most economical method of
combatting this insect in truck gardens was found to be the
growing of immune plants under constant cultivation and free-
dom of weeds during the summer when the fields are not ordi-
narily used for planting of truck. The work of the past year fur-
ther confirms our previous experience that this method, if care-
fully and thoroughly followed out, will so reduce their numbers
during a single summer as to make the growing of truck crops
during the following winter reasonably profitable, although it
does not ordinarily result in a complete eradication. Heretofore
the grower has been practically confined to a single cover crop,
velvet beans, but experience during the past two years would
indicate that Crotalaria is also immune to root-knot attack and
can be used for this purpose. Although grown in heavily in-
fested land, we have not seen a single case of this plant being at-
tacked by root-knot. Crotalaria, however, is somewhat slower in
its growth than velvet beans and can be used only when the sum-
mer truckless season is comparatively long.
For treating seedbeds nothing better has been discovered
than the double treatment of sodium cyanide and ammonium sul-
phate heretofore used. A treatment with formaldehyde gave
practically as good results but it is even more expensive, espe-
cially in view of the fact that it does not, as does the other
method, leave large quantities of valuable nitrogenous fertilizer
in the soil. On the other hand, it has the advantage in that it also
kills out certain fungous diseases. For growers who wish to
sterilize the ground for both fungous diseases and root-knot, the
use of formaldehyde would be advisable.

Over a thousand parasites of the cane borer (Loxophaga) were
received from Cuba and liberated during the fall. We have not
been able to recover these in the field where liberated. However,
the borers are much scarcer in this field than a year ago. As this
condition also seems to prevail in other fields, we have no assur-
ance that it is due to the presence of the parasites.


Florida Agricultural Experiment Station


The Florida flower thrips became extremely abundant during
April but the outbreak was too late to damage the citrus bloom
or young fruit. Most of the control work on this insect on citrus
was along the endeavor to develop a combination control for
this insect and the green citrus aphid. The dusts which have
been found most economical for aphids have not given very ef-
ficient control of thrips on citrus. They do not sufficiently
penetrate the blossoms. A driving spray is needed for this. As
a result of the work of the past year it seems that the Florida
flower thrips is not as strictly confined to blossoms as hereto-
fore believed. It seems able to breed on any very tender vegeta-
tion. It has been a severe pest on snap beans and peanuts.
The tobacco thrips has been found rather commonly to infest
narcissus, but as yet the infestation has not been sufficiently
heavy to be of any commercial importance.

At the laboratory for the study of pecan insects at Monticello,
which was established last year (see report for 1927, page 47R),
studies were continued along about the same lines as during the
first year. An insectary has been built which greatly facilitates
this work. The shuckworm was found to be less injurious than
last year. It was also later in emerging from the pupa. Further
experiments as to plowing under the shucks during the winter
as a control measure indicated that this plowing should not be
too early in the season. If the plowing is done while the insects
are still in the larval stages, some of the larvae will work up
through the soil and pupate near the surface from where they
can successfully emerge; whereas if the plowing is done after
they have transformed into the pupal stage, the result is much
better. Further work will be necessary in order to ascertain
the best time for this winter plowing.
Further experiments and sprays for the nut case-bearer show,
as indicated by the study of the feeding habits of the caterpillar
(see report for 1927, page 48R), that spraying with arsenicals
is of no value as a control measure for this insect. Dormant
sprays would seem to be the most practical means of controlling
it. Several oils and oil emulsions are being tried out. Other in-
sects being studied in this laboratory are the leaf case-bearer,


Annual Report, 1928 49R

fall webworm, walnut caterpillar, black hickory aphid, yellow
hickory aphid, spittle bugs, tree crickets, and the hickory twig
Close study has been made of the various parasites of these
pecan pests.

Florida Agricultural Experiment Station

Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Horticulture for the fiscal year ending June 30, 1928.
Associate Horticulturist, in Charge.

Work in this department was continued on much the same
basis as for the preceding year.
The systematic study of the methods and problems involved
in the production of a number of horticultural crops was con-
tinued. Citrus was given the most attention but blueberries,
persimmons, pears and some miscellaneous fruits also were
studied carefully. The information collected on blueberries was
compiled in a general information bulletin. The same is being
done for Japanese persimmons. Correspondence concerning the
various fruits has been increasingly heavy and the information
collected in this way is used in answering letters of inquiry.
Similar work is being started on avocados, mangoes and other
tropical fruits. The demand for information on tropical fruits
has been exceedingly heavy and it is difficult to keep in touch
with developments along this line, from this Station.

Studies on the effect of cold on citrus and the artificial heating
of groves have been continued. Old groves that were partially
protected against wind were heated very successfully in the
northern portion of the citrus belt, the temperature being raised
from 7 to 100F. with ordinary firing methods. As previously
noted, the firing of young groves in which the trees were too
small to obstruct the movement of the air was very much less
successful than the firing of the larger groves. This is probably
to be expected when the cold is accompanied by any wind, as
the mixing of the air would tend to prevent the development of
any considerable inversion of temperature and the efficiency
of the heating would be correspondingly reduced.
During the course of firing the groves it was found that when
the temperature was maintained at 27 to 271/20F. no ice formed
in Pineapple oranges. But if the temperature was maintained


Annual Report, 1928

at this point for some time and then dropped, ice would form
in the fruit in a few minutes. No ice was found in the oranges
in a grove that was maintained at 27 to 280F. for 10 hours, but
under similar conditions when the temperature fell to 260, after
having been held at 271/0 for several hours, ice started to form
in the fruit in a few minutes. It is, of course, probable that
the freezing point of oranges may vary from year to year and
also from grove to grove, but the figures would appear to be
relatively reliable. It was noteworthy that where a temperature
of 260 was maintained for some hours all oranges examined
showed ice. Oranges in which only a small amount of ice was
formed did not appear to be materially injured by this condition
and hung on the trees for two to three weeks afterwards and
shipped in good shape, though occasional masses of hesperidin
crystals could be found. There was no softening of the fruit.

Work was continued on the physiology of fruit production,
and the growth curves for Parson Brown, Pineapple and Val-
encia oranges, and Walters grapefruit were completed for the
1927 season (Valencia oranges recorded until the freeze of Janu-
ary 2 and 3 destroyed the fruit). The curves of growth were
found to be closely correlated with the rainfall, particularly
during the spring period when a prolonged drouth took place.
The Parson Brown and Pineapple orange studies were carried
on at Lowell and the growth rate dropped off steadily until
June 12, when the drouth at that place was broken by a heavy
rain. The data for these studies are being compiled and the
studies continued during the present year on Pineapple and Par-
son Brown oranges. Work on grapefruit and Valencia oranges
was discontinued because of severe damage to the trees by cold.
Studies on the effect of fall applications of nitrogenous mate-
rials on the growth of tangerines and Parson Brown oranges
'were started. Such applications failed to produce any material
increase in the size of the fruit. In the case of tangerines a
slight increase in size may have been obtained but only a frac-
tion of the amount necessary to increase the fruit one size in
During the course of the experiments it was found that there
was a considerable diurnal variation in the size of the fruit and
as a consequence all measurements were made in the early morn.-


Florida Agricultural Experiment Station

ing between 4 a.m. and 10 a.m. This variation in diameter is
undoubtedly due to the withdrawal of water from the fruit by
the leaves during the periods of the day when transpiration is
extremely high, and may have an important bearing upon the
drying out of fruits at the stem end. In order to study this phe-
nomenon further, an apparatus was designed to record continu-
ously the diameter of a single fruit, but the fruit on the Station
grounds was destroyed by cold about the time that the apparatus
was perfected.
In this connection it was noted that previous work as carried
out in California, by Waynick, utilized diameter measurements
as a criterion of growth, whereas the growth of the fruit is
actually a growth in volume. Such a volume growth would vary
as the cube of diameter if the fruit were spherical or nearly
spherical rather than varying directly as the diameter (volume
of a sphere=1/6 d ds). Though there is bound to be some in-
equality in shape, it must be conceded that in all probability
the plotting of the cubes of the diameters would produce a curve
of growth more nearly representative of the situation than
would the plotting of the diameters themselves. The inaccuracy
involved in the use of the diameter as such manifests itself in a
false diminution in the rate of growth as the fruit increases in
size, as may be readily visualized by considering the following
theoretical case: An orange 10 mm. in diameter when increased
to 12 mm. diameter would increase approximately 381 cubic mm.
in volume, but an orange 70 mm. in diameter when increased in
volume by the same amount (381 cubic mm.) would increase
only .053 mm. in diameter. Thus if a sphere be imagined to
grow in volume at a uniform rate per unit of time the curve for
the diameters of the sphere would show an apparent reduction
in rate of growth as the sphere became larger.
It is obvious from the above discussion that the plotting of
growth curves for fruits would need to be a function of volume
and for this purpose either the actual volume or the cube of
diameter would be the most satisfactory unit to use where the
form of the fruit is spherical or nearly so.

Most of the trees in the variety test orchard are making excel-
lent growth, many of them have reached an age and size suffi-


Annual Report, 1928

cient for nut production. Three trees, two Randall and one
Moore, set and produced 13 nuts in 1927. The following num-
bers of pecan trees of each variety mentioned have set nuts the
present year: 3 Frotscher, 2 Success, 4 Schley, 2 Moneymaker,
4 Kennedy, 2 Randall, 1 Moore, 2 Teche, 1 Van Deman, 3 Ris-
ing, and 1 Seedling Japanese Walnut.
A mixture of Crotalaria sericea and Crotalaria striata with
a scattering growth of beggarweed produced about 11,000
pounds per acre of green material that was turned into the soil.
The area in the new farm, devoted to pecan and other nut cul-
tural investigations, was planted to Crotalaria sericea which
yielded an average of about 5,000 to 8,000 pounds of green mate-
rial to the acre, which was returned to the soil.
Very few pecan nuts were produced in 1927 west of the Apa-
lachicola River on account of the severe injury to the trees,
caused by the September, 1926, storm. Therefore, there was no
yield record for the fertilizer experiments in that part of the
state. There was a fair to a good production on all of the other
fertilizer experiments except the one in Columbia County, near
Lake City.
While the data at hand cannot be interpreted in terms that
would be conclusive at the present time, it is felt that progress
is being made and that worth while information will come from
this line of work, as soon as sufficient time has been given to it.
On account of the severe losses caused by the shuckworm, scab
and the excessive dry weather during the remaining part of
1927, there was no harvest of nuts in the rejuvenation experi-
ment in Jefferson County. The owner is not giving the good co-
operation that was manifested during the first two years of
the experiment, and for that reason, the results to date are not
as encouraging as they would have been otherwise.
The trees are making satisfactory growth of twigs and trunk
circumference when moisture conditions and treatment in 1927
are considered. The foliage has a dark green color and is very
abundant when compared to the color and condition at the begin-
ning of the experiment. There was a very heavy bloom of pis-
tillate and staminate flowers this spring, which resulted in a


Florida Agricultural Experiment Station

fair set of nuts, but losses are being had from injury caused by
the nut case-bearer, the shuckworm and scab.
Table II gives the varieties, average annual gain in trunk
circumference, and the total gain of the trees in the rejuvena-
tion experiment. It will be observed that there has been a fairly
consistent average annual gain after the first year. Although
1927 was a dry one and the orchard did not receive the care that
it should have, the gain in circumference growth that year was
almost as great as that in 1926, demonstrating that definite re-
sults are being manifested in trunk growth.

(Jefferson County)
Gain in Centimeters

Variety 1925 1926 1927 Total Gain

Curtis ...........----- 0.1 5.0 4.4 9.5
Russell ..........-......... 2.2 4.1 3.3 9.6
Young --- .........I 0.2 6.6 2.9 9.7
Frotscher ............. 0.3 4.4 4.3 9.0
Pabst ................ 0.6 5.9 3.9 10.4
Schley -..-..---..--............. 0.3 4.3 3.2 7.8
Stuart ................... 1.5 3.6 4.2 9.3
Average of all
varieties ........... 0.74 4.84 3.74 9.32

Trees in the rejuvenation experiment being conducted in Clay
County are showing marked improvement in condition as well
as encouraging prospects for an increased yield of nuts.

The plots of trees in the rosette experiment receiving the man-
ure only and the commercial fertilizer are showing a gradual
improvement in condition. The general appearance of the trees
as well as twig growth in the manured plot is better than those
in the one where commercial fertilizer is used. By referring to
Table II it will be seen that the percentage increase in produc-
tion of nuts is very satisfactory for the manured plots when com-





Fertilizer Per

Manure and


II 4-8-4 50
and Cover


SVan Deman
I Randall


Van Deman


III Nothing Schley
Sand Cover Schley
Crops. Van Deman


No. Year
Trees Planted

2 1917
1 1911
2 1911
1 1911
2 1911
4 1911
1 1911
1 1911




Percent Total
Average Annual Yield Increase Per
Per Tree in Pounds 1927 Over Tree
1925 1926 1927 1925

0.0 1.0 4.0 5.0
50.0 7.5 59.0 116.5
66.5 9.0 73.0 148.5
64.5 4.5 93.0 162.0
20.0 12.2 23.8 56.0
15.2 16.1 28.1 59.4
6.0 0.0 5.0 11.0
41.2 0.0 119.0 160.2

263.4 50.3 404.9 53.7 718.6

0.2 0.5 1.5 2.2
14.0 0.6 31.0 45.6
0.0 1.7 0.0 1.7
0.1 0.1 0.8 1.0
42.0 0.2 100.0 142.2
18.1 0.4 18.8 37.3

74.4 3.5 152.1 104.4 230.0










Florida Agricultural Experiment Station

pared with the one receiving the commercial fertilizer. The
yield of the unfertilized plot has decreased 18 percent since the
work started. Summer cover crops of velvet beans have been
grown on all plots each year. It is well to state that the per-
centages have been figured from the production of 1925, as that
of 1924 was too light to harvest.
Table III gives the plots, varieties, yields and treatments by
years for the rosette experiment.
The cover crop experiments have been enlarged to include a
study of the effect of various soil building crops on tree growth
and nut production. The experiments are located in two or-
chards in Jefferson County, one being made up of 15 to 20 year
old trees and the other composed of five year old trees.

~ ry:.T.~Yfs'I

Fig. 1.-Austrian winter peas in this cover crop experiment produced
16,500 pounds of green material per acre.

Austrian winter peas and hairy vetch, planted October 26,
1927, produced an average of 16,500 and 13,500 pounds, respec-
tively, per acre of green material by April 24, 1928. Besides add-
ing large quantities of organic matter, much nitrogen that is
taken from the air is also added to the soil. Monantha vetch,


Annual Report, 1928

also cats and rye, are being used in experimental plots in testing
the value of winter cover crops. Crotalaria sericea continues to
give good results as a summer cover crop.
Measurements are being made to determine the rate of growth
of pecan trees in both trunk and twig development. A dendro-
graph has been set up on the tree trunk of a young Kennedy pe-
can tree and a continuous record is being kept of the growth.
Measurements of twig growth indicate that there is a close cor-
relation between size and length of twig and nut production.

In the test grounds, work on projects as noted in previous
reports has been continued, particular attention being given to
propagation experiments. Plantings of miscellaneous materials
have been increased somewhat during the year, although con-
siderable loss of both young and old plants was caused by the
extremely low temperatures of the past winter.
Although not to be considered as conclusive, the following data
on results of fertilizer experiments with the tung-oil tree may
tend to show the trend of fertilizer requirements, more partic-
ularly of young trees. The figures given are for trees in their
fifth year, planted on a Norfolk sand soil type. The oil and mois-
ture content of the seeds was determined by Dr. Henry A. Gard-
ner, research director for the National Varnish Manufacturers'
Aleurites montana (the Mu-oil tree) continues to make a very
vigorous growth but as yet has produced little fruit. The trees
were in a very dormant condition at the time of the cold period
of January last and were not injured by 150 Fahrenheit. Hy-
brids of this species and A. fordi have been secured by cross
pollination, A. montana being used as the male parent.
A satisfactory apparatus for maintaining a controlled tem-
perature to supply bottom heat for rooting cuttings was devised.
(Fig. 2.) The equipment consists of a flanged pan, 30" x 60" x
5", of a fairly heavy gauge of galvanized iron, set on the ordi-
nary greenhouse bench. The pan is fitted with two flanged holes




Sodium nitrate ...........
Bone meal ...........-
4-8-4: ammonium sul-
phate, blood, super-
phosphate, muriate of
potash ...................
Superphosphate ...........
Muriate of potash...-...
Superphosphate, muri
ate of potash ..........
Manure ........ ...... .......
Check .....................
Cottonseed meal, bone
m eal ...........................
Lim e only .....................
5-8-4: sodium nitrate
ammonium sulphate
superphosphate, muri
ate of potash, plus
lime as above ............
Check ........ ................
5-8-4 without lime ......
Manure .-.........................
5-8-4: cottonseed meal
sodium nitrate, super
phosphate, muriate of
potash .......................
Bone meal ...................

1 Seeds Seeds jSeeds to Weighi
I (Cluster)* (Single) 1 Pound
]Av. per Tree Ave. per Tree I Cluster | Single
SLbs. | Oz. Lbs. Oz.
.. 5 13 7 3 162 145
S 4 9 2 4 164 128

5 10 2 8 153 141
2 2 1 7 164 153
S 2 14 1 2 148 142

S 4 14 0 10 170 138
. 6 2 2 1 162 158
.. 3 0 0 5 152 145

.. 5 3 3 7 150 128
2 7 1 12 155 117

. 4 12 3 0 140 126
. 3 3 0 14 140 100




Tree Average Oil and Water Content
Hgt. Spd. I Cal. I Cluster Single
Ft. I Ft. I In. I Water I Oil Water C
93-5 113 3-7 4 1-2 6.8 31.2 6.9 3
91-3 11 3-5 4 1-4 7.8 36.1 7.4 31

92-1511 2-5 4 1-4 7.2 34.1 7.6 3'
84-5 913-151 3 1-3 6.7 32.5 7.4 31
9 7-15 1013-15| 3 3-4 7.4 35.3 8.1 3

10 2-1511 7-15 4 1-3 8.1 36.9 7.4 3
10 2-15 12 8-15 4 3-4 7.7 32.5 7.2 3&
83-5 914-15 3 1-2 7.3 33.6 6.8 3i

95-12110 2-3 1 3 3-4 7.1 35.1 7.3 3:
8 1-3 9 1-12 3 1-6 6.8 34.0 6.8 3'

101-2 Il1 1-4 3 2-3 6.6 31.8 6.8 3.
71-6 7 5-6 2 2-3 8.7 33.1 7.7 3i
10 11 7-12 4 1-4 7.2 35.3 7.3 3
9 10 3 1-4 7.4 32.7 7.2 3

91-2 11 1-2 3 5-6 8.1 32.9 7.8 3,
10 7-12i11 1-2 I 3 7-12 7.6 32.9 7.6 3

*The "single" or "cluster" seeds refer to the fruiting habit in what is evidently two types of trees, i.e., whether the fruit
is borne singly or in clusters on the individual twigs.


Annual Report, 1928

in the bottom, one near each end, for the attachment of a 11/4"
pipe into which an electric bayonet heater is inserted. The
method of arrangement of heater and pipes results in a thermo-

warrB4 or ralfrfl
lt _ _ J ___ ---------

Fig. 2.-Apparatus for maintaining controlled temperatures in cutting bed.

siphon system, this causing a constant circulation of water in
the pan during the time the heating unit is in operation. By
means of a thermostatic control, any desired temperature above
prevailing air temperatures may be maintained with but slight
Sphagnum moss, to a depth of about an inch, placed over hard-
ware cloth, acts as a support for and prevents the cutting sand
from washing into the water below and at the same time allows
free passage of heat from the water to the sand.
The whole is enclosed with 1" dressed lumber except the top,
this being two hinged sashes which permit easy access to the
cuttings and allow regulation of ventilation.
The size of the pan is limited by the capacity of the heating
unit used and could be increased by the installation of addi-
tional heaters.

Investigations dealing with the effect of soil temperature and
soil moisture upon the growth of Irish potatoes have received
major attention for the year just ended. Experiments were con-
ducted at Hastings, Penney Farms and LaCrosse, where plant-
ings were made at weekly intervals beginning about January 10
and ending the middle of February. An effort is being made to
correlate the yields with the soil temperature and soil moisture
obtaining during the growth period of each of the respective
plantings. With such data accumulated over a period of several


Florida Agricultural Experiment Station

years, it is believed that the date of planting for the production
of maximum yields may be determined within certain limits.
These correlations have not been computed from the data ob-
tained this year. Table V shows the results obtained from
the Hastings area where 10 replications were made for each


Planting Name Bb's.
Date of Per
Plot Acre

n. 10 ..... X
n. 17 ..... Y ......
n. 23 ........ A 74.12
n. 30 ........ B 83.68
!b. 6 ........ Check (C) 78.94
!b. 13 ........ D 80.83
*b. 20 --.... E 68.40

Primes Per- Sec-
Bbls. cent onds
Primes Bbls.

...---. ...... .. --.... -----

50.81 68.55 17.32
52.53 62.77 16.40

57.26 72.53 18.10
51.36 63.54 21.40
40.86 59.73 20.90

cent Culls Per-
Sec- Bb!s. cent
onds Culls




C= 8.2% More barrels primes than B.
C=10.3% More barrels primes than D.
C=13.0% More barrels primes than A.
C=25.0% More barrels primes than E.
D & E had no chance to make any growth during last 2-3 weeks, too
much water.

From these data it is evident that the potatoes planted on
February 6 made the best yield of prime potatoes. The plant-
ing made on February 13 would no doubt have produced the
largest yield, but for the extremely heavy rainfall which killed
the vines two weeks prior to harvesting.
The data in Table VI show the yields obtained from the vari-
ous plantings made at LaCrosse.
From these data alone it is difficult to draw any very definite
conclusions, due to the extreme variability of the soil in which
the various plantings were made; also to the high percentage of
Rhizoctonia found in most of the plantings. The virulence of
the disease varied, however, with the soil moisture relations in
various parts of the field. This may explain in part the fact


Annual Report, 1928

Total Barrels Percent Barrels Percent Percent
Plot BArel Primes Primes Seconds Seconds Culls
Per Acre

Check I ............ 106.64 91.86 86.14 10.91 10.23 3.63
A ................... I 96.51 67.97 70.42 17.95 18.59 10.99
Check II ........- 107.74 89.92 83.46 9.97 9.19 7.35
B ................... 103.44 82.98 80.22 13.59 13.13 6.65
Check III .......... 92.92 73.81 79.43 12.60 13.56 7.01
C ...............I 89.59 68.57 76.53 13.81 15.41 7.06
Check IV .......... 92.12 68.97 74.86 14.02 15.21 9.93
E ................. 96.31 72.61 75.37 14.46 15.01 9.62
Check V ............ 100.70 76.18 75.65 14.41 14.30 10.05
F ..................- 87.50 39.20 66.65 15.93 18.20 15.15
Special F ......... 109.43 84.44 77.16 11.01 10.06 12.78
Check VI .......... 99.22 72.91 73.48 14.06 14.17 12.35

that the yields throughout the entire series of plantings showed
a close correlation with the percentage of soil moisture as de-
termined from the mean weekly soil samples taken at specified
points in the field during the growing period. This correlation
is shown in the accompanying graph (Fig. 3).
On January 3, a minimum temperature of 210F. was recorded
at Hastings. Again on February 19 270 was recorded. Some
of the earliest potatoes planted at Federal Point were dam-
aged severely by both of these freezes. The February freeze
caught the experimental plots at various stages of development.
The plantings made on January 10, 17 and 23, respectively, were
all above ground. In each of these, some few plants were left
untouched by the cold while the majority were killed down to
or below the surface of the ground. Fifty or more plants in each
of the series were marked and a corresponding number of frozen
plants were marked adjacent to the unfrozen ones. These were
harvested separately and yields of primes, and seconds were
taken for the first four plantings. The planting of January
30 (Plot B) was hardly through the ground, while practically
none of the sprouts in plot (C) were touched by the cold. Table
VII shows a summary of the yields from the four plantings.
It appears that there is a critical stage in the development of
the potato plant when a severe freeze is most damaging. The
potatoes in plot "Y" seemed to be at that stage at the time of
the February 19 freeze.
The effect of a mulch of cane pomace applied to potatoes
planted February 1 was studied at LaCrosse. Due to the very


Florida Agricultural Experiment Station

/jo zi ii


1 "11111 I- I I I
.... ,.

6 /o /7 14-
PercenTaqge of soil


Fig. 3.-Correlation of yields of potatoes with mean soil moisture for
growing period taken at weekly intervals at LaCrosse. Different parts
of the field showed an average soil moisture variation of 8 to 18 percent.
cool and wet spring following the application of the mulch on
March 8, the effect was to accentuate the virility of the Rhizoc-
tonia disease so prevalent in the field, so that the yields from


Annual Report, 1928

Yield Bbls. Per- Bbls. Per- Per-
Planted Bbls. Primes cent No. 2's cent cent
P. A. Primes No. 2's Culls

Plot "X" Jan. 10 Frozen 57.89 29.67 1 51 19.54 33 16
Unfrozen I 69.18 44.36 64 16.64 24 12
Plot "Y" Jan. 17 Frozen I 64.40 31.85 49.4 20.98 32 19
Unfrozen 77.86 47.76 61.0 21.52 27 12
Plot "A" Jan. 23 Frozen j 78.69 44.14 56 26.00 33 11
Unfrozen 1 75.98 58.18 76 15.92 20 4
Plot "B" Jan. 30 Frozen i 93.35 61.51 65 28.22 30 5
Unfrozen I 97.69 I 77.07 79 17.36 17 4

the mulched areas were considerably reduced as compared with
the unmulched. The Rhizoctonia was present in practically 100
percent of both the mulched and unmulched areas, but the detri-
mental effects were not nearly so marked in the unmulched.

A small planting of the two year old asparagus roots (Aspara-
gus officinalis) was made under the slat shade on the Horticul-
tural trial grounds in 1926. Very excellent top growth has char-
acterized their development for the two summers past, and due
to the very cold weather during December, January and Febru-
ary just past, complete dormancy was effected. As a result, sev-
eral very desirable shoots were produced from each plant upon
its resumption of growth the latter part of February. These
were not removed.
A further study on the effect of temperature and moisture on
the bean mosaic was made this spring. Seed from plants show-
ing 100 percent mosaic infection was planted alongside seed
from mosaic-free plants grown at the Arlington Farm, Virginia,
the preceding summer. The plants from the mosaic infected seed
showed only a trace of mosaic as compared to none from the
mosaic-free seed. A subsequent planting made to determine the
effects of the drier, warmer weather, was killed by unfavorable
weather and bacterial blight which came from an adjoining
commercial planting before any data could be taken.
Several plantings were made of the Iceberg variety of lettuce
with the intention of studying the effect of temperature and soil
moisture upon its heading. The ground was infected with root-
knot, which nullified the work.


Florida Agricultural Experiment Station

In Memoriam

O. F. BURGER, 1885-1928


Annual Report, 1928

Wilmon Newell, Director.
SIR: I submit the following report of the Department of
Plant Pathology for the fiscal year ending June 30, 1928.
Associate Plant Pathologist,
Acting Plant Pathologist.

During the year the Department of Plant Pathology has been
working in cooperation with the State Plant Board in investi-
gaticns of citrus canker and identifications of diseased speci-
mens sent in by grove and nursery inspectors and with the Of-
fice of Vege.ab.e and Forage Diseases of the United States De-
partment of Agriculture in tomato disease investigations.
A considerable amount of new and necessary equipment has
been added to the laboratories of the department and to the lab-
cratories of several of the field stations.
The departmental library has been increased materially with
scientiLc publications and books in the field of bacteriology, my-
cology and plant pathology.
A storage and tool house 20 x 20 feet was built on the station
grounds for the purpose of housing dust and liquid fungicides
and machinery used in applying the same. It also affords stor-
age space for field implements, stakes, greenhouse flats, pots,
hose, etc.
The facilities for experimental work in Manatee County on
tomato diseases were materially improved by the clearing of
the remainder of a 20-acre tract, thus making available several
acres of new land. A well was sunk, pump provided, irrigation
pipe laid, pump house and barn built and drainage ditches dug at
the expense of the county.

Heterothallism in Blakeslea trispora Thax.
By George F. Weber and Frederick A. Wolf. Mycologia 19:
302-307. 1927.
Diseases of Lettuce, Romaine, Escarole and Endive.
By G. F. Weber and A. C. Foster (U. S. D. A.) Fla. Agr.
Exp. Sta. Bull. 195:300-333. 1928.


Florida Agricultural Experiment Station

Owen F. Burger. By G. F. Weber, Phytopath. 18, 8:627-630,
The Downy Mildew, Sclerospora graminicola, on Everglade
Millet in Florida.
By Wm. H. Weston, Jr. and George F. Weber, Jour. Agr.
Res. March, 1928.
Water Requirements of Citrus Trees.
By A. S. Rhoads, Citrus Industry 8:6-9. 1927.
Water Injury to Citrus Trees in Florida.
By A. S. Rhoads, Citrus Industry 9:7-11. 1928.

(Inspections made and notes taken by David G. A. Kelbert.)
The melanose experiments have been continued in the Atwood
groves as described in previous reports. The grove was divided
into blocks and four different brands of oil sprays were used in
conjunction with 4-4-50 Bordeaux mixture.
The grove was inspected the latter part of May (three to six
weeks after the Bordeaux spray had been applied) and very
little melanose was found on the old growth and none on the
latest flush. The young fruit showed no infection.
The oil spray caused considerable damage in spots, causing
what has been termed "shadowing", which appears much like
a spray burn, resulting in dark brown blotches from 1/8 to 1/2
inch in diameter on the young fruit. These spots grow with
the fruit and are very unsightly on the mature fruit, little if any
being removed during the process of washing and drying for
Following is a summary of the melanose spraying experiment
in which 4-4-50 Bordeaux mixture was followed by four differ-
ent oil emulsion sprays in 1927-28.

Block Application ean Scale Shadowing Drops

1 oil "A" trace bad 8-10% 2%
2 oil "B" trace fair 5- 8% 2%
3 check trace control* none 10%
4 oil "C" 3% control 3- 5% 2%
good com.
5 oil "D" trace control trace 2%


Annual Report, 1928

During the particular seasons of the year very little melanose
developed on any of the check plots, consequently the value of
the sprays in that respect cannot be definitely determined.

K. W. Loucks has conducted the investigations on citrus can-
ker. Following is his report:
Investigations concerning the viability, longevity and decline
of Bacterium citri (Hasse) Jehle in soils of various types have
been continued along lines previously reported. These studies
also include the rate of growth of the causal organism in vari-
ous environments. The optimum and maximum temperatures
for the growth of the organism have been definitely established
at: Opt. 28-300C.; Max. 400C. Growth took place at 100C., the
lowest temperature tried. The organism growing in broth was
killed when exposed to a temperature of 48C. for five minutes.
Hydrogen peroxide killed the organism in culture tubes in 30
seconds or less. The organism did not pass through a medium
chamberlain filter, as determined by plating filtrate. Neither
did the filtrate produce any noticeable effect on healthy leaves
through inoculation.
It was shown that kumquats were somewhat resistant to the
disease when inoculated, but that they were not entirely immune.
A number of permanent slides of diseased and healthy tissue
on the various hosts have been made. Other histological studies
are in progress from the viewpoint of showing the complete life
cycle in the development of the disease and a study of symptoms
on the different hosts at various temperatures.
One hundred and twenty collections of suspicious looking
specimens were sent to the laboratory by grove inspectors of
the State Plant Board. By careful examination and comparison
84 were definitely diagnosed as not being infected with citrus
canker, the other 36 were plated and inoculations made and one
proved to be citrus canker caused by Bacterium citri (Hasse)
Cucumber disease investigations were conducted by Dr.
George F. Weber and several student assistants.
Angular leaf spot.-Due to an entirely unfavorable season
and laxness of growers in disinfecting their seed, angular leaf


68R Florida Agricultural Experiment Station

spot was more or less prevalent over the central portions of the
state on cucumber plants.
The disease was first noticed in some of the experimental plots
which were being treated for downy mildew. The organism was
isolated from leaf spots from a field several miles south of
Gainesville and about two weeks later, an organism was isolated
from rotted fruits from an entirely different field. These two
organisms were grown in pure culture, direct and reciprocal in-
oculations made. The spots developed on the leaves of the plants
inoculated with the organisms isolated from both the leaves and
the fruits. Fruits that had been inoculated at the same time
with both organisms, did not show lesions until about 10 days
later. The organisms were reisolated from both the leaves and
infected fruit and it can be conclusively stated that B. lachry-
mans (E. F. S.) Bry. is the causal organism for angular leaf
spot and fruit rot. These experiments verify a similar series
of experiments conducted in 1926.
Downy mildew.-The cucumber season in the vicinity of
Gainesville was about three weeks later than usual. Blight ap-
peared about the time of the first picking and as usual was se-
vere, killing the plants before the fields were necessarily aban-
doned because of marketing conditions.
Approximately 5 acres divided into 4 plots were used in experi-
ments to which various fungicides were added for the control
of this disease. Comparisons were made between fungicides of
sulphur and copper constituents. Sulphur appeared to be much
more detrimental this season than last and did not prove to be
as good a fungicide as Bordeaux mixture spray or copper car-
bonate dust. Copper carbonate averaged somewhat better than
Bordeaux mixture in the various plots, giving a fair commer-
cial control and holding the vines in production 10 days to, two
weeks longer than the check plants.
An experiment was conducted in which 2-4-50 Bordeaux was
applied to 50 percent of the plants, the others receiving no
fungicides. The pistillate and staminate flowers and set fruit
were counted. The conclusions which may be drawn from this
single season showed that there was considerable injury in pro-
duction by the Bordeaux spray.
The tomato disease projects were conducted by Dr. George
F. Weber with the aid of the field assistants, David G. A. Kel-

Annual Report, 1928

bert, stationed in Manatee County, and Stacy Hawkins, in Dade
Since the hurricane of September 18, 1926 the rainfall of
Dade County has been considerably below normal. In addition
to dry weather, the following enumerated factors were import-
ant in causing a short crop during the past season; continued
cold and frosts, excessive winds, bad off-type seed and insect
pests. Mosaic plants also appeared in larger numbers than ever
before. Diseases were not important and nailhead rust did not
spot 1 percent of the fruits in any of the plots in the 12 acres
to which fungicides were applied. The work and fungicides were
similar to those reported last year.
In Manatee County the situation was quite different in rela-
tion to the appearance of nailhead rust, even though many of the
other factors were comparable to those in Dade County.
The spraying experiments were conducted along lines similar
to last year and comparable to those in Dade County. Nailhead
was a serious factor in the crop and on the check plots spotted
about 40 percent of the fruit. The copper sprays reduced the
abundance of the disease to 24 percent. Copper dust showed 30
percent and sulphur dusts showed 38 percent, or only slightly
better than the check plots.
Staked tomato plants showed less nailhead than unstaked
Investigations on the occurrence, sources and spread of mo-
saic were conducted by Dr. S. P. Doolittle, U. S. D. A., with head-
quarters in the Manatee County Field Laboratory.
At the Main Station several Marglobe varieties selected the
year before have been grown and further selections made. The
host range of certain Alternaria spp. have been studied in both
field and greenhouse, including inoculation experiments.
Indications are that early blight of tomato, potato and egg-
plant are caused by Alternaria solani (E. & M.) J. & G. and that
nailhead rust of tomatoes is caused by another distinct Alter-
naria sp. A Stymphylium sp., undescribed as far as known, has
been found to be of considerable importance on solanaceous
plants. This organism has been grown in pure culture and its
pathogenicity proven by inoculation experiments. Its host range
has been partially determined and a description is being worked


Florida Agricultural Experiment Station

Certain investigations, surveys and mycological work have
been conducted by Erdman West, whose report is as follows:
The investigation of scaly bark of citrus was conducted, in
both field and laboratory. The old Phillipi Hammock grove at
Safety Harbor and the Terwilliger Grove at LaGrange were
given excellent care last year. Many of the old badly infected
trees were removed, but the remaining trees are being observed
to note their reaction to these changed cultural conditions, espe-
cially in regard to new scaly bark infections. The old Indianola
Hotel property on Merritt's Island is still neglected and a con-
siderable amount of infection of young wood occurred in this
grove. Two weeks were spent in the grove this spring in an at-
tempt to isolate a causal organism of the disease. Numerous
cultures secured are now being purified. These organisms and
such as are obtained from later isolations will be used for inocu-
lation experiments. Scaly bark infected trees obtained in the
Lake Beresford Nursery recovered while kept in the greenhouse
during the past 12 months.
Several weeks were spent in making three separate disease
surveys of a majority of the commercial ferneries in the state.
At least two important fungus troubles are present which merit
further investigation, a leaf blight caused by a species of Hel-
minthosporium and a stem disease of unknown cause. Most
"rust" seems to be due to senility, assisted by various semi-
parasitic organisms incapable of attacking vigorous plants.
Considerable improvement was made in the herbarium in
equipment and by the addition of several thousand mycological
and phanerogamic specimens. Six modern steel insect-proof
cases were acquired, making a total of eight in the herbarium
rooms in the new fireproof Horticultural Building.
The mycological herbarium was increased this year by about
600 specimens, sent in for identification by correspondents, col-
lected by various members of the department, from the United
States Department of Agriculture at Washington in return for
certain Florida material, and by exchange with other institu-
The old phanerogamic herbarium has been revised and used
as the foundation collection. Nearly 2,000 new sheets were ob-
tained through the activity of the various members of the de-


Annual Report, 1928

apartment. About 100 more northern plants were obtained by
exchange. The entire herbarium of Prof. A. Cuthbert of Bra-
denton, Fla., was given to the Experiment Station. This collec-
tion consists of more than 3,000 sheets collected principally in
Florida and the southern United States. It entirely fills one steel
case and while it is to remain intact for the life of the donor, it
is very valuable for reference as it contains many uncommon
The herbarium, even in its present incomplete condition, has
rendered valuable and readily available assistance in the identi-
fication of native plants that otherwise would have been neces-
sarily obtained from outside of the state. There is no other
herbarium available in the state at present.
Through inquiries nearly a thousand specimens of diseased
plants were received during the past 12 months along with a
number of other requests for information on plant diseases.
These specimens were examined, the cause of the trouble de-
termined and the sender informed by mail as to the best methods
of combatting the trouble or preventing its recurrence in future
crops. In about 20 percent of the cases, cultures were neces-
sarily made before the true nature of the cause of the trouble
was ascertained.
Approximately 200 identifications of plants, both wild and
cultivated, have been made during the past year for citizens in
various parts of the state and for departments of the Univer-
sity. The latter included poisonous plants for the Veterinarian;
weeds for the Agronomist; various wild plants, insect hosts,
for the Entomologist; official plants for the Pharmacy School
and wild citrus relatives for the State Plant Board.
Several specimens of honey comb were examined for the pres-
ence of the American Foul Brood bacteria in the spore stage.

The investigational work on citrus blight and psorosis has
been conducted by Dr. Arthur S. Rhoads, whose report is as fol-
During the past two years the primary investigational work
conducted at the laboratory at Cocoa has been the development
of control methods for psorosis and gummosis. A total of 277
trees treated previously, have been inspected and, in a few cases,
they have been re-treated when necessary. The re-treated trees


Florida Agricultural Experiment Station

were principally those which were first worked on and the
methods developed were not adequate to insure complete recov-
ery. The re-treated trees as a group also included the older,
larger trees, which in most cases were severely affected. Dur-
ing the past year 253 trees, consisting of grapefruit, orange,
tangerine and satsuma, were scraped and various fungicides
applied. The treatment as a whole has been considerably im-
proved and it has been found that dry lime-sulphur (1/4 pound
diluted in 2 quarts of water) gave very good control. This dis-
ease was also well controlled by the usual scraping methods and
the application of a paste made by mixing equal parts of dust-
ing sulphur and hydrated lime, enough water being added to
make a paste of the right consistency. Ordinary Bordeaux paste
also was found to be of considerable value and each of these
three fungicides proved to be superior to the various brands of
carbolineum that are available and usually have been recom-
mended. Examination in the grove shows that a large number
of trees have contracted the disease apparently from pruning
Clitocybe tabescens (Scop.) Bres. has been under continuous
observation. It has been found killing the common guava, Aus-
tralian pine, and Cattley guava (first report) and an instance
was observed where the fungus was infecting a peach tree from
a nearby guava.
During the year continued observations have been made on
drought and water injury in their relation to blight and data
have been collected in an attempt to correlate these diseases with
soil types. Observations and notes have been continuously made
on the young citrus plantings, which were budded from typi-
cally blighted trees. At this time some of these trees are more
than three years old and continue to remain healthy.
Supporting the evidence obtained on the work of wilt and
the correlated soil types, watering experiments have given good
results and on the strength of these experiments, numerous irri-
gation systems have been installed in various groves. As addi-
tional evidence is accumulated, the evidence points unquestion-
ably to the extremes of soil moisture as the chief factors in the
development of blight on citrus trees.
About 100 specimens of flowering plants have been collected
in this vicinity and sent to the herbarium at the Main Station.


Annual Report, 1928

The investigational work on strawberry diseases has been
conducted by Dr. A. N. Brooks, whose report is as follows:
The field laboratory on two acres of land located at Spring-
head, southeast of Plant City, was completed August 1 and the
laboratory equipment was moved there from the Growers' Build-
Anthracnose, caused by the organism Colletotrichum sp., a
disease of strawberry runners, although not widespread last
fall, was found to be quite serious in the field belonging to T. J.
Black (Cork), Plant City, where it caused a loss of from 5 to
10 percent of the young plants being formed at that time. The
causal organism has been studied and described, but not def-
initely identified as to species. Although leaves escape the dis-
ease under field conditions, it has been produced by artificial
inoculation on petioles and midribs under controlled conditions.
A search for a wild host plant of this organism has been made,
but as yet none has been found. Partial control of the disease
has been secured with Bordeaux mixture 4-4-50.
Inoculation experiments with Mycosphaerella fragariae, the
causal organism of Mycosphaerella leaf spot, show that the Mis-
sionary variety is not resistant to this disease when environ-
mental conditions exist favorable for its development. Experi-
ments have shown that it can be controlled by Bordeaux mix-
ture 4-4-50.
On May 16, 10 days after artificial inoculation with Dendro-
phoma obscurans, the causal organism of leaf blight, spotting
was apparent on inoculated plants and these spots are still
gradually increasing in size (May 22). Leaf blight is found to
be more common in the Florida fields than is the Mycosphaerella
leaf spot. Successful control has been demonstrated by two ap-
plications of Bordeaux mixture 4-4-50.
Leaf scorch, caused by the fungus Diplocarpon earliana, was
abundant during the extremely dry summer months of 1927.
The crimping, stunting, and reddening of the leaves known
as "crimps", which appears to a certain extent each year, was
serious during the fall of 1927. An organism has not been dem-
Unhealthy condition of the roots, usually in the form of a
root rot, causes considerable damage each year to the strawberry
plantings. This diseased condition of the roots is probably not


Florida Agricultural Experiment Station

due primarily to fungus invasion but is the result of several
factors working together.
Although root-knot is generally present in Florida soils, its
relation to strawberry has not been deemed of much importance.
The most severe case of this trouble was seen near Vero Beach
where one field was found in which 25 percent of the plants had
been killed.
Due to the dry, cool weather prevailing during the fruiting
season the fruit rots caused by Pezizella sp., Rhizoctonia sp.,
Phytophthora sp. and Botrytis sp. have been of minor import-
ance both in the field and in transit.
Other phases of the investigational work in which some data
have been accumulated may be classified as follows: control of
fruit rots by washing in weak disinfectant, study of pony re-
frigerators in relation to development of Rhizopus rot, methods
of handling fruit found to reduce accumulation of moisture in
refrigerator, shipping of pre-cooled fruit without ice, smother-
ing of strawberries in airtight containers, ripening of straw-
berries after picking, observations on strawberry insects, var-
iety tests, Florida-grown plants for fall setting, and frost pro-
The investigational work on Irish potato diseases has been
conducted by Dr. L. 0. Gratz, whose report is as follows:
No late blight (Phytophthora infestans de By.) was observed
or reported from any part of the potato belt this season. Early
blight (Alternaria solani (E. & M.) J. & G.) became severe as
the plants matured. Southern brown rot (Bacillus solanacearum
E. F. S.) developed rapidly until checked by rains and slightly
cooler weather about March 15. The total injury for the sec-
tion was comparatively small.
The experimental work consisted of seed treatment and spray-
ing and dusting experiments, spindle tuber disease studies, and
varietal responses, in both symptoms and yields, to various dis-
eases under Florida conditions.
In the seed treatment experiments comparisons were made
by treating seed potatoes with corrosive sublimate, semesan bel
and dipdust. With the first treatment one plot consisting of 7
replications yielded a 4 percent increase in marketable tubers.




5-5-50 Bordeaux ......................--

Copper lime dust ..........-.....

Increase (barrels) .............

over (percent).............

dust (odds) ..................

5-5-50 Bordeaux ..........................

Check ................ ............ ..

Increase (barrels) ............

over (percent) .............

check L (odds) ...............

Copper-lime dust ............. ...

Check .... .............. ....................

Increase (barrels) .............

over (percent).................

check (odds) ................

No. of Barrels
*No. 1 *No. 2

30 75.31.59 18.3 .394

30 63.41.23 19.9 .376

11.72.00 -1.6 .547

18.73.15 -8.0 .28

19,230:1 22:1

12 78.61.50 19.4 .476

12 75.10.97 20.7 .323

3.51.79 -1.3+ .574

4.72.38 -6.3 .277

4.6:1 7:1

8 54.50.99 21.91.09

8 64.81.37 21.80.36

-10.31.69 0.11.14

-15.9-2.61 0.46.523

19,230:1 1:1

*No. 1-Primes; No. 2-Seconds; M-Marketable.

culated Yield per Acre

*M -Nc

93.61.53 8

83.31.20 7




98.01.59 8

95.71.13 8




76.31.63 7




S 267:1

Percent per Grade
. 1I No. 2 M

0.4 19.6 100.0

6.2 23.8 100.0

0.2 19.8 100.0

8.7 21.3 100.0

1.3 28.7 100.0

4.9 25.1 100.0

Florida Agricultural Experiment Station

Semesan bel in two plots of 7 and 8 replications each resulted
respectively in a yield increase of 1.3 percent and 3.0 percent
marketable tubers. Dipdust, in 3 plots consisting of 10.7 and
8 replications, yielded definite decreases of 14 percent and 6.7
percent marketable tubers in two plots, and an increase of 21
percent in the third plot.
Table VIII gives the average data obtained from the spray
and dust plots. Four applications were made per plot. Late
blight (Phytophthora infestans de By.) was entirely absent, and
early blight (Alternaria solani (E. & M.) J. & G.) which was
practically controlled by Bordeaux mixture, was severe only the
last few weeks. Significant increases by spraying were obtained
where spraying was compared with dusting, and significant de-
creases by dusting where the use of copper-lime dust was com-
pared with no treatment.
Samples carrying 100 percent spindle tuber were again com-
pared with healthy lots, and the seriousness of this disease, if
not checked, was again demonstrated, as indicated by the yields
in Table IX.



Healthy ...-.... ..
Spindle tuber ....
Barrels increase
Healthy over
spindle tuber
Odds ...............

No. Calc. Yield in
of Stand Barrels per Acre
Repl. *No. 1 *No. 2| *M

10 99.8 87.2 19.9 107.1
10 64.2 19.1 8.6 27.7

68.1 11.3 79.4
**M:1 4999:11 **M:1

Percentage per
No. I No. 21 M

81.4 18.6 100.0
69.0 31.0 100.0

*No. 1-Primes; No. 2-Seconds; M-Marketable.
**Million to one.

The Spaulding Rose No. 4 was compared with Irish Cobblers,
Green Mountains and Bliss Triumphs and was found to carry
less disease than these other varieties. All of the samples tried
were considered to be the best commercial lots available and
were found to produce high yields as shown in Table X.


Annual Report, 1928

Yield in Barrels per Acre
Primes Seconds Marketable
Maine Spauldings ................. ............- 69.9-1.65 15.5.414 85.4-1.88
Prince Edward Island Spauldings-....... 86.11.95 12.6.688 98.7-2.14
"Bill Spud" Spauldings ....................... 60.8-1.32 15.2-.672 76.01.77
Maine Irish Cobblers ............................ 59.7_1.40 8.7- .310 68.441.41
Maine Green Mountains ..............-... 61.4-1.43 11.4-.650 72.8-1.80
Nebraska B:iss Triumphs ... ................ 61.1-1.78 11.41.500 72.5-1.65

Ten replications each 60 feet long were planted for each variety.

Investigations of the diseases of the citrus aphid have been
conducted at the Lake Alfred Branch Station by Wm. A. Kuntz,
whose report is as follows:
The host range of Empusa fresenii, the fungus attacking the
citrus aphid, up to the present time is citrus aphid, melon aphid,
brown citrus aphid and the grape aphid. Zygospores of the fun-
gus were collected in October, 1927. Infection has been extreme-
ly light during the past spring. The influence of humidity and
temperature in relation to the activity of the fungus has been
studied. Atmospheric moisture is probably one of the most im-
portant factors. Data have been collected from 70 trees for the
past three years on the occurrence of the aphids and the pres-
ence of the disease. Catch crops have been experimented with
and variations in symptoms of the disease on aphids noted under
different conditions. The dissemination of the disease is prob-
ably centered around migrating adults over distances up to 500
yards. Inoculation experiments were conducted on tented trees
with some success. Zygospores have been developed in the lab-
oratory on infected material. The conditions surrounding this
development are being studied. Their germination has not been
observed. The perpetuation of the disease apparently depends
upon whether or not the aphids killed by the fungus die on heav-
ily infested trees.


Florida Agricultural Experiment Station

The investigation of pecan diseases, principally scab (Fusi-
cladium effusum Wint.), has been conducted by R. E. Nolen
in the field laboratory at Monticello, whose report is as follows:
The experimental work has been conducted along lines sim-
ilar to those reported last year. A new power sprayer has been
added to the equipment of the laboratory. Spraying and dust-
ing operations in cooperation with various growers constitute
the major part of the work. Comparisons are being made of the
efficiency of various sprays and dust in the control of scab. The
determinations for comparison are made by making counts of
lesions on leaves, nuts and twigs on the variously treated blocks
of trees. The correct time of application and the number of
applications also are receiving considerable attention. Consid-
erable variation in susceptibility of varieties of trees to infec-
tion has been noted and is an important factor in making new
The laboratory work has been continued in which the fungus
is being studied and the perfect stage sought.


Annual Report, 1928

Wilmon Newell, Director.
SIR: I submit the following report of the Veterinary Depart-
ment for the fiscal year ending June 30, 1928.

There has been considerable expansion in the work of the
Veterinary Department during the past year.
Work has been conducted during the fiscal year on the fol-
lowing projects: (1) Manson's eyeworm of poultry, (2) kidney
worms of swine, (3) "salt sickness" in cattle, (4) paralysis
and coccidiosis in poultry, and (5) Daubentonia seed poisoning
in poultry.
Studies on the life history of Manson's eyeworm were con-
tinued during the year. These studies were carried out in the
field laboratory located at Bradenton. Further observations on
the life history of the kidney worm in swine were made. The
work on these two projects was conducted by Dr. D. A. Sanders.
His report follows:

The work on Manson's eyeworm described in previous reports
has been continued. After experimentally producing eyeworm
infestation in the domestic fowl and in many species of wild
birds, some of the nematodes in the eyes were removed at vari-
ous intervals in order to make observations on their develop-
ment. Thirty days after the infestation had occurred the sex
organs were well developed but lack of eggs in these organs
showed that the female parasites were not wholly mature.
Forty-eight days after infestation the uteri of worms taken
from the eye contained numerous eggs, many of which contained
the coiled embryo indicating that the parasites had reached the
sexually mature stage. Likewise, a microscopical examination
of the eye fluid and of the intestinal contents of diseased birds
48 days after infestation revealed the presence of eggs of the
Since it was unknown how the embryos entered the body cav-
ity of the cockroach, which is the intermediate host of the eye-


Florida Agricultural Experiment Station

worm, and since the subsequent development of the larvae with-
in the roach was unknown, it was thought advisable to conduct
certain experiments to determine data on these questions. In
conducting the experiments embryonated eggs were secured by
teasing mature female eyeworms in normal salt solution. The
eggs were incubated for 48 hours, after which time they were
thoroughly stirred into a custard mixture and placed before
caged nymphal roaches which had been reared under controlled
conditions and therefore definitely known to be free from eye-
worm larvae. Within 48 hours the roaches had ingested all the
custard mixture containing the eggs. The food regularly pro-
vided for the roaches consisted of a commercial poultry mash
and in addition some carefully selected lettuce leaves were given
daily. After feeding the roaches eyeworm eggs, frequent ob-
servations were made, which involved dissecting and examining
microscopically numerous roaches in an effort to determine the
stage of development and the location frf the larvae of the eye-
worm within the roach. These observations revealed the follow-
ing facts:
On the first and second day after the eggs were eaten they
were found in the crop and intestine of the roach. Examinations
made on the third, fourth and fifth days after ingestion of the
eyeworm eggs revealed the presence of larval forms of the para-
site, measuring 0.2 mm. in length and located free in the intes-
tine. On the eighth day the larvae were found free within the
body cavity and were 0.4 mm. in length. Examinations made on
the 20th day showed that the larvae had encysted within the
body cavity of the roach, the length of the larvae being 1.0 to
1.5 mm. On the 30th day, the larvae were 2.5 to 3.0 mm. in length
and were encysted within the body cavity. Examinations made
on the 40th and 50th days showed the larvae to be 4.0 to 5.0 mm.
and 6.0 mm. respectively in length, and encysted within the body
Infestation of the eyes by feeding these roaches at various in-
tervals was negative until the 50th day. At this time six young
cockerels were fed a number of nymphs and all six became in-
fested. An examination of roaches which have been heavily in-
fested as in this experiment showed that it is common for two
or three worms to be present in the same cyst. The control
roaches fed and handled in an identical manner to the experi-
mental roaches were free from larvae in all cases.


Annual Report, 1928

It remained to be determined if the roaches would become in-
fested by ingesting droppings of diseased birds and if the time
period required for the larvae to reach the infective stage was
subject to variation. To determine these points a number of
roaches were isolated in test cages, starved for several days and
then allowed access for 72 hours to freshly voided droppings of
a chicken severely infested with the eyeworm. Evidence was
very apparent that the.roaches consumed a sufficient quantity
of infected droppings for the purpose of the experiment. The
roaches were then allowed the usual ration which consisted of a
commercial poultry mash but were not given any green food.
Examinations of the roaches at various intervals showed that
they became infested by having access to droppings of diseased
birds and that the time period required for the larvae to reach
the infective stage in this experiment was approximately 100
days after the last possible feeding. Thus it is seen that the time
period required for the larvae to reach the infective stage may
vary according to the food supply of the insect.

KIDNEY WORM (Stephanurus dentatus) OF SWINE
Investigations of the life history of the kidney worm of swine
are now being carried out. The eggs of the species gain entrance
to the urinary bladder from the parasitic cysts through fistulous
tracts and are passed to the outside with the urine. Eggs ob-
tained from the urine by various concentration methods are
found to be in an advanced stage of segmentation. Such eggs
are capable of hatching in 48 hours at room temperature, thus
liberating the first stage larvae. Further studies relative to the
life history of this parasite will be conducted in the future.

Definite research work on paralysis and coccidiosis of poultry
was begun during the past year. Work on these two diseases has
been conducted by Dr. E. F. Thomas. His report follows.
Numerous post mortem examinations were made on diseased
birds sent to this department for diagnosis. Research work on
fowl paralysis was commenced during the fall of 1927. This is
a disease of chickens that is characterized by paralysis of the
limbs and affects birds from four to 18 months of age, usually


Florida Agricultural Experiment Station

taking its largest toll just about the time the pullets reach the
age for egg production.
From observations made on numerous cases of fowl paralysis
investigated by this department the following symptoms were
noticed. The disease is one of partial and progressive paralysis
of the legs, wings, and other organs of the body. One or both
legs may be affected. Both feet may extend forward or back-
ward, or the bird may lie on its chest with one leg extended for-
word and the other leg extended backward. When the wings
are affected, they are drooped down by the side. The colored
parts of the eye (iris) are often discolored or else present a
greyish coloration. The bird is usually blind when the eyes are
so affected. Blindness may or may not be associated with paraly-
sis of the wings or legs. There is a great loss of flesh; the dis-
eased birds have a depressed appearance and are very unthrifty.
Diarrhea is usually present, and this symptom persists for sev-
eral days. The diseased birds may linger for weeks and finally
die. Some cases show an improvement in the paralytic condi-
tion at intervals, yet the improvement is only temporary since
the birds go down again with paralysis, usually within a few
days time.
From numerous post mortem examinations made in this lab-
oratory on birds affected with paralysis the following conditions
were noted: About 80 percent of the autopsied birds showed in,
flammation of the mucus membrane of the duodenum and most
of the cases so affected showed the presence of coccidia in the
contents and scrapings of the intestinal tract. The nerve sup-
ply to the limbs was affected in a large percentage of the para-
lyzed birds. About 20 percent of the birds showed the presence
of intestinal worms. Lesions involving the liver were found in
40 percent of the diseased birds.

Treatment of paralysis has not proven successful. A strict
sanitary program carried out in a thorough manner on the in-
fected premises gives the most promising results of any method
used in controlling the disease. Where it is impossible to clean


Annual Report, 1928

the grounds and houses which have been used by the diseased
birds, it will be found necessary to change the healthy birds to
new, uncontaminated grounds in order to attempt to control
Since the cause of paralysis is still an unsettled question, ex-
periments are being conducted by this department in an attempt
to determine the cause of the disease. These experiments include
the feeding of intestinal contents of paralyzed birds to healthy
chicks, the intestinal contents being subjected to various labora-
tory tests before being fed. Also, comparisons are being made
between chicks hatched from eggs obtained from badly diseased
flocks and eggs obtained from flocks in which paralysis has
never occurred. None of these experiments have yet been com-
pleted. Further work will be conducted along this line.
Coccidiosis has been quite prevalent in this state during the
past year, judging from the numerous birds sent to this depart-
ment for examination and also from the cases observed in in-
vestigating poultry diseases in various sections of Florida. In
the course of these examinations it has been noted that appar-
ently two types of coccidiosis are present-the duodenal and the
cecal types. The duodenal type has been found in the duodenum
of many adult birds affected with paralysis. In at least 50 per-
cent of the young chicks affected with coccidiosis, the coccidia
are found infecting the duodenum. The cecal type is found most
prevalent in young chicks, though occasionally it is detected in
the adult birds. The cecal type is very fatal in young birds. The
old birds, having the duodenal coccidiosis, harbor the disease
in a chronic form and undoubtedly act as "carriers" of the coc-
cidia, serving thereby as a constant danger and menace to the
rest of the flock, especially to the young chicks that are permit-
ted to run with the older birds. Several outbreaks of coccidiosis
in young chicks have been traced to hens that had chronic duo-
denal coccidiosis.
Medication is of little value in coccidiosis. The most success-
ful control measure is to provide clean, dry, sanitary poultry
houses, keeping the houses and premises clean at all times, and
feeding rations of easily digestible and highly nutritious feeds.


Florida Agricultural Experiment Station

Further observations have been made on "salt sickness" in
cattle during the year. It was impossible to make these observa-
tions in a systematic manner due to the fact that the owners of
the affected cattle kept these cases under range conditions, and
only general information could be obtained. Evidence obtained
from such studies tends to show further that cattle affected with
"salt sickness" can overcome the condition by having access to
a balanced ration to which bone meal has been added.

A poultry owner in this state had several hens to die which
showed symptoms of some peculiar type of poisoning. He held
several post mortem examinations and found numerous Dauben-
tonia seed in the intestinal tract of a few of these birds. A large
quantity of the seed was sent to this department and tests were
conducted to determine if the Daubentonia seed were toxic. A
total of 34 birds were used in the course of the tests, and all of
these birds died as a result of eating the seed. Daubentonia seed
are highly toxic for poultry, and as few as nine seed will cause
The first symptom noted in Daubentonia seed poisoning is a
staggering gait, followed by a drooping of the wings. The feath-
ers are ruffled, and the bird shows signs of profound depres-
sion, general debility and unthriftiness. The comb becomes dark
purple in color and drops over to one side of the head. Muscular
twitching (jerking) is noted over different parts of the body. A
profuse diarrhea is present, even in the early stages of the dis-
ease. When the symptoms are prolonged for three to eight days,
there is a rapid loss of flesh and extreme weakness is noted.
Many seed pass through the digestive tract in an undigested
condition and such seed, when fed to poultry, are also toxic.
No drug has yet been found to serve as an antidote for Dau-
bentonia seed poisoning. The poisoning may be prevented, how-
ever, by simply picking and destroying the seed pods before they
reach maturity, since the toxic agent is contained within the


Annual Report, 1928 85R


In addition to conducting research work on the above men-
tioned projects, the department has maintained a diagnostic
laboratory, and diseased specimens from the various classes of
livestock have been sent to the laboratory for a diagnostic re-
port on same. These specimens are received from practicing
veterinarians, officials of the State Live Stock Sanitary Board,
and livestock owners themselves. During the year 1,077 diag-
noses were made.
Numerous inquiries concerning diseases of livestock, includ-
ing poultry, have been received and information given on these
The department has rendered considerable veterinary services
to animals belonging to the State Farm at Raiford.

Florida Agricultural Experiment Station

Wilmon Newell, Director.
SIR: I submit the following report of the Department of Ag-
ricultural Economics for the fiscal year ending June 30, 1928.
Agricultural Economist.

The work of the Department of Agricultural Economics for
the year was a continuation of the four projects reported for
the previous fiscal year and the inauguration of a fifth project
for the purpose of studying the economics of dairy farming in
Florida. The work can best be summarized by projects.

This study was completed during the year and the results are
incorporated in bulletin 193 of this Station. A copy of the bul-
letin has been sent to each of the 294 potato farmers who fur-
nished the data for the study. Some of the facts and conclu-
sions derived from the study are mentioned here.
The average capital invested in these potato farms was $22,726
per farm. It was found that the 50 farms with the highest in-
vestment and the 50 farms with the lowest investment were not
so profitable as the 194 farms having investments between these
Eighty-seven percent of the total farm receipts came from
the potato crop. As a rule, the farmers obtaining the highest
percentage of their receipts from potatoes made the largest
labor incomes.
The four expense items constituting approximately 80 percent
of the total expense on these farms were: Human labor (exclud-
ing operators') 23.8 percent; fertilizer, 24.3; seed, 15.2; and
containers, 16.5.
One third of the labor on potatoes was performed before har-
vesting and two-thirds was required in harvesting and market-
The percentage of the different grades of potatoes in 1925 was:
Number 1 -----.-------------..................... 73.2
Number 2 --........................- 19.5
Number 3 ... ......... 5
Culls ................ ------------ ...... 6.8


Annual Report, 1928

There did not appear to be any correlation between the pro-
duction of Florida potatoes and the price received for them.
The size of the late Northern potato crop of the preceding year
has a pronounced effect upon the price of the Florida crop.
The operators who had always engaged in farming made bet-
ter labor incomes than did those transferring from other occu-

This project has also been completed and is now in manuscript
form. As soon as a few minor corrections are made, it will be
submitted for publication.
The average cost per box of picking, hauling and packing cit-
rus fruit for the 99 houses in 1924-25 was 95 cents, but the
range in cost per box was from 74 cents to $1.50. The costs per
box were considerably higher in 1925-26, due primarily to the
smaller crop handled.
The principal factors influencing the costs of handling citrus
were found to be volume of fruit per packinghouse, volume of
fruit per grower, percent of the season the packinghouse was
operated at full capacity, and the percent of the total fruit
packed represented by grapefruit.

Some progress has been made during the year in the analysis
of these survey data, though it has been necessary to devote
much time to other lines of work. More concentrated effort will
be given to the completion of this study in the near future.

The following progress report on the above project is made
by M. A. Brooker, who is in charge of the study.
The citrus transportation project has been pushed steadily
and a large amount of data has been secured. A brief survey of
the World Citrus Situation, and a history of the development of
the citrus industry in the United States have been included as


Florida Agricultural Experiment Station

preliminary to the cost of transportation study. A study of the
monthly distribution of citrus shipments from the various pro-
ducing areas has been made. The geographical distribution of
the citrus crop over a four-year period was also studied, and
Table XI gives some of the results of this study.

(FouR YEAR AVERAGE 1923-24 TO 1926-27.)
Percent of Percent of Percent of
Number Population Percent of Total Total
Section States (Census of Total (Grape- (Com-
1925) (Oranges) fruit) bined)

New England ............ 6 7.0 11.3 9.1 10.4
Eastern --------.......-- 5* 23.1 44.6 34.8 40.7
Midwest .. .....-- ..... 5 20.5 14.6 26.2 19.2
Southeastern ........... ... 10 19.4 25.3 13.7 20.6
Western .....-...........--- 22 30.0 3.6 14.6 8.1
Canada ...... .. ...... ........... ......... ... .6 1.6 1.0

*And the District of Columbia.

The new England States contain two of the 36 largest citrus
markets in the United States.
The Eastern Section, containing the states of New York, New
Jersey, Pennsylvania, Delaware, Maryland and the District of
Columbia, has seven of the 36 largest citrus markets.
The Midwest Section, made up of the states of Ohio, Indiana,
Illinois, Michigan and Wisconsin, contains eight of the 36 larg-
est citrus markets in the United States.
The Southeastern Section, made up of the 10 states south of
the Ohio and Potomac rivers and east of the Mississippi river,
but including no part of the state of Louisiana, contains four
of the 36 largest citrus markets.
The Western Section includes the 22 states lying west of the
Mississippi river including the whole of Louisiana, and has 15
of the 36 largest citrus markets in the United States.
The burden of the cost of transportation work deals with a
comparison of the freight and refrigeration charges from rep-
resentative citrus shipping points in the various producing
areas to the 36 largest citrus markets in the United States; also
with the preparation of index numbers of freight rates from 18


Annual Report, 1928

citrus shipping points in Florida, and a like number in Cali-
fornia, to 9 common destinations, since 1900, using the 5-year
average, January 1, 1910-December 31, 1914, as a base period.
The data for these studies were secured personally, with the aid
of a rate expert, from the official files of the Interstate Com-
merce Commission.

Work on this project was started in December, 1927. The pur-
poses of the project are to determine as accurately as possible
the following facts concerning the dairy situation on Florida
1. The economic status of the Florida dairy farmer.
2. The costs of and the returns from milk production.
3. The possibilities for decreasing the costs of milk produce.
tion on Florida farms by pasture improvement, more home-pro-
duced feeds, better cows, and other methods.
The survey method is being used and the collecting of the field
data is practically completed. The procedure has been to secure
the names of all Florida dairymen selling milk in some of the
principal Florida cities and make personal visits to each of these
dairy farms to obtain directly from the operator a financial
record of his business for the fiscal year ending December 1,
1927. No records were obtained from dairymen with less than
six cows or who had been in the business for less than a year.
The cities chosen were Jacksonville, Miami, Tampa, St. Peters-
burg, Orlando and Ocala, and the following number of farm
records have been secured from each area upon which to base
the study: Jacksonville, 66 records; Miami, 38; Tampa, 66;
St. Petersburg, 27; Orlando, 40; Ocala, 35. Office work on
these records is in progress.


Up to the present time, most of the work of the Department
has been based on the survey method of research. This was
necessary in order to obtain a general economic picture of farm-
ing conditions in this state, and much more of this type of work
should be done. In making these personal visits to farmers,
however, the scarcity of any kind of financial record keeping
was pronounced. Perhaps one of the greatest reasons for this
is that most of the prepared accounting forms are for commer-


90R Florida Agricultural Experiment Station

cial businesses and not adapted to farm accounting. A number
of farmers visited expressed the desire for suitable accounting
forms for their business. It was with this idea in mind that
the Department has prepared and has on hand for free distri-
bution to Florida farmers the following types of accounting
forms for their use:
A Method for Taking a Farm Inventory.
A Method for Keeping a Cash Account on a Farm.
A Method for Keeping an Account with a Dairy Cow Herd.
A Method for Keeping an Account with a Crop.
There is perhaps no quicker or better way of analyzing a farm
business, in order to find ways for making improvements, than
from the use of well kept records on that farm.

Annual Report, 1928

Wilmon Newell, Director.
SIR: I submit the following report of the Home Economics
Department for the fiscal year ending June 30, 1928.
Home Economist.

The work of the department for the last year has been a con-
tinuation of the projects reported in 1927.
Biochemical and biological laboratories have been equipped.
An animal house has been built with adequate facilities to care
for the present experimental and stock animals. A departmental
library has been organized and at present contains about 180
In the determination of whether chlorophyll, chlorophyll alpha
and beta, the petroleum ether extracts of the yellow pigment of
alfalfa can be used as a source of vitamin A in animal nutrition,
alfalfa seeds germinated and ungerminated, alfalfa seedlings
grown for 10 days in the light and in the dark have been tested.
When albino rats 30 days old were placed on a vitamin A-free
diet and allowed to decline in weight, alfalfa plants grown in
full nutrient solutions in either light or dark were able to re-
store weight and cure xerophthalmia. Germinated seed were
able to restore weight and cure xerophthalmia, though they were
not as effective as the seedlings. The dry seed afforded protec-
tion but were not effective as a cure for xerophthalmia. The
materials were fed dry at the rate of 1 gm. per day per rat. This
experiment has been repeated three times with the same results.
Two hundred rats have been used.
Experiments have been conducted to determine whether the
anti-rachitic factor was the limiting one; 70 rats 30 days old
were fed on extracted basal (Sherman), and ashless filter paper,
and were placed for 1 hour each day in the sun. At the end of
60 days when the rats were 90 days old, 70 percent were still


Florida Agricultural Experiment Station

gaining, and the remainder were stationary or losing in weight.
There were no indications of xerophthalria. The weather be-
came variable and the rats were kept indoors. Xerophthalmia
developed in 90 percent of the rats. When some of the rats were
posted, rachitic lesions and beaded ribs showed that the anti-
rachitic factor had not been controlled. When alfalfa seedlings
grown in either light or dark were added to the diet there was
a prompt recovery in all cases. When soap made from stearic
acid and NaOH was added to the diet of rats as a prophylactic
there was a slight increase in weight and at the end of three
months there were no indications of xerophthalmia.

Experiments to determine the most effective means of control-
ling the anti-rachitic factor; 50 rats used.
1. Extracted basal (Sherman) (irradiated 1 hr. distance 1
m. mercury quartz vapor lamp) + 4 hrs. of sun on the rat-
2. Extracted irradiated basal + irradiated cholesterol --
3. Extracted basal + sunlight (4 hrs.) on the rat + soap.
The following checks were used:
4. Stock food.
5. Basal (extracted with alcohol and ether) + soap.
6. Basal (extracted according to McCollum) + soap.
Rats on rations 5 and 6 died in four to six weeks and showed
symptoms of rickets and symptoms typical of the lack of vita-
min A, xerophthalmia, loss of appetite, emaciation and respira-
tory defects.
Rats on ration 2 died only a few days later than those on an
unirradiated food and showed the symptoms typical of lack of
vitamin A.
Whether the anti-rachitic factor had been controlled on ration
2 was not conclusively proved by the examination made. X-Ray
photographs are now being made to determine it.
Rats on rations 2 and 3 showed no indication of xerophthalmia
after 12 weeks, though they were stationary as to weight. The
femurs from these rats will be x-rayed to determine the degree
of calcification.


Annual Report, 1928


The following pigments have been prepared and are now be-
ing fed:
1. Chlorophyll.
2. Ether extracts of the yellow pigments.
Dr. F. M. Schertz has sent to this laboratory crystalline chlo-
rophyll and four chlorophyll derivatives. These pigments are
now being tested.

Histological sections have been prepared from rats fed on
stock food, and from rats fed on vitamin A-deficient diets. Sec-
tions have been prepared from the following parts of the rats:
1. Stomach, 2. brain, 3. intestine, 4. ovaries, 5. oviduct, 6. testes,
7. thyroid, 8. spleen, 9. pancreas, 10 liver, 11. thymus.
Thus far special study has been given to the stomach, testes
and liver.
Sections of stomachs from rats on vitamin A-deficient diets
show an absence of mucosa, disintegration of much of the musci-
lar tissue, and in most cases localized ulceration. These ulcers are
situated along the elevated ridge which divides the rumen from
the glandular part of the stomach. No lesions have been found
in rats on complete diets, but of rats on vitamin A-deficient
diets, 100 percent showed lesions and degeneration of the mu-
Sections from the testes of rats on vitamin A-deficient diets
show progressive degeneration of the germinal epithelium of
the seminiferous tubules, finally resulting in loss of the germ
Livers of experimental rats showed a spotted appearance and
in more advanced cases the livers became gray in color.

Aseptic surgical operations are being performed on experi-
mental rats to determine the internal condition of the rat. It
has been observed that the great momentum has almost disap-
peared. A small remnant was found at its place of attachment
on the greater curvature of the stomach. Ulcers were removed
from the stomachs and small pieces were taken from the livers
for sectioning. The rats were then put on special food and al-
lowed to recover. They are to be operated on again to determine


Florida Agricultural Experiment Station

whether the rat has been able to regenerate the tissues of the
stomach and momentum and whether the liver has regained its
normal appearance when put on a complete ration. This work
is still in progress.

A nutritional study of the school children of five representa-
tive counties of Florida has been in charge of Dr. C. F. Ahmann.
Following is his report:
Physical examinations and laboratory tests have been made
thus far on children of four representative counties of Florida.
Data were taken on the diets of these children. Records of the
progress in school were made of all children to determine who
were retarded in their school work.
In County IV, where data were collected in 1927-28, 1,828 chil-
dren have been examined. The data for 1,218 of these children
have been tabulated up to date and will be herein reported.
The following tables give the data collected in the survey for
four counties.

Percent Percent Percent
County N umber e Percent Percent
Number Under- c Defective Eye
Examined weight aries ee Hookworm
weight Tonsils Disease

I............ 144 66 48 58 18 All treated
II ........... 322 40 38 36 7 29
III ......... 247 75 23 43 48 54
IV .......... 1,828* 45 46 49 23 52

*Percent calculated for 1,218 children.

Those cases which were underweight and free from hookworm
will be studied with respect to diet.
The data of pupils who are retarded in school are being stud-
ied in relation to diet and physical defects.
Table XII shows the prevalence of defects by sex.
Those cases which were found anemic but free from hook-
worm are being studied with respect to diet of this group. Of
these 87 percent had faulty diets; that is, one deficient in green
leafed vegetables, fruit or milk.


Annual Report, 1928


SBoth Sexes

Disease or Defect

Total ........................

Without Defects ...........

With Disease or Defect

t ......


Underweight (10 percent
and over) ....................-

A nem ic ............................

Eye Defects:

Defective Vision ..................

Other Defects ..........------


Decayed Teeth ..........--

Defective Tonsils .---............


Cervical Glands ....-...........--

Heart Defects: ................

Skin Defects: ...............


Hookworm ......................

Tapeworm ..............--..........

A scaries ..............................































Boys Girls
Num- Per- Num- Per-
ber cent her cent

541 45.7 642 54.3

31 5.7 46 7.2

510 94.3 596 92.8

78 14.4 115 17.9

























Investigation of the factors affecting the jellying of citrus
fruits, loquats, etc. was conducted by Dr. L. W. Gaddum. Fol-
lowing is his report:
The general plan of the project calls for:
(1) Analysis of the fruits.
(2) Study of the effect of various methods of extraction on
the quality and yield of pectin obtained.


Florida Agricultural Experiment Station

(3) Study of the physical and chemical properties of the pec-
tin obtained from the various fruits.
Some time has been spent in working out analytical methods
and in organizing the laboratory work.
The work is at present in the first stage; commercial pectins
and fruits in season are being analyzed. It is expected that one
more year's work will complete this phase of the project.
After the analytical work is completed, it is planned to pur-
sue during the next biennial period the study of extraction meth-
ods and the properties of pectin.
Since pectin occurs in large amounts in the albedo of citrus
fruits and also in loquats, guavas, etc., it is hoped that a thor-
ough study of the properties of pectin may reveal methods of
profitable utilization of much of Florida's waste pectin.

In an effort to determine the cause of spoilage of non-acid
vegetables in the South, two methods have been used.
(1) Vegetables canned in this laboratory in a pressure cooker
according to the directions sent out by the Bureau of Home
(2) Vegetables canned in homes in pressure cookers accord-
ing to methods they are in the habit of using, spoiled products
being sent to this laboratory.
Examinations are made to determine whether spoilage is due
to leakage or underprocessing. By the use of a pressure cooker
the organisms are limited to spore-forming types.
Examinations of products canned in this laboratory have
shown that spoilage is caused by leakage due to poor rubbers.
This loss is less than 2 percent. There has been no spoilage due
to under-processing.
Examinations of products sent to this laboratory has shown
that much of the spoilage is caused by leakage. Contents of some
of the jars, however, have spoiled due to flat, sour organisms.
Non-gas-forming, spore forming bacteria, isolated from
spoiled and sound canned foods, are being studied to determine
types significant in the production of flat, sour spoilage. Two
larger thermophylic groups, a facultative thermophylic group,
and an obligative thermophylic group, have been defined as
causing this type of spoilage. Work is being continued on the
identification of these organisms.


Annual Report, 1928

Wilmon Newell, Director.
SIR: I submit the following report of the Library for the fiscal
year ending June 30, 1928.

The principal work of the present fiscal year was the removal
of the Library from the Experiment Station into the new Hor-
ticultural Building. This was accomplished in September, 1927.
Owing to the fact that the same book stacks were to be used, all
material had to be removed from the shelves and packed in
boxes. This was a difficult piece of work, though it was success-
fully accomplished in a short time. The rearrangement of the
material in the new building was more complicated and required
more time to complete.
The new library room has given very little additional floor
space. A badly needed office was provided however, which has
materially added to the efficiency of the work being done.
Routine work has grown heavier, owing to the constantly in-
creased use of the Library by the Experiment Station staff, fac-
ulty and students of the College of Agriculture. Graduate stu-
dents, in particular, have made heavy demands on the facilities
of the library and with the increase of projects by station work-
ers, demands for research literature have increased correspond-
ingly. It is the desire of the librarian to meet all these demands
and where the library cannot take care of the many requests, she
has enlisted the aid of other libraries through the inter-library
loan. As usual, the library of the United States Department of
Agriculture, Library of Congress, and other large libraries have
been most prompt in their assistance, supplying volumes that
were not available in this library.
It is gratifying to report that the collection of scientific and
agricultural literature has had a number of important additions
for the present year. Many thousands of reports, bulletins, etc.,
all valuable publications of the various Experiment Stations and
Departments of Agriculture, of this and foreign countries, have
been received and cared for. The shelves have received 352 new
volumes, while 209 volumes were prepared and sent to the


Florida Agricultural Experiment Station

Cataloging and indexing have proceeded as rapidly as other
demands permitted, and, although this work was entirely aban-
doned through the weeks of moving and rearranging the Li-
brary, 10,748 new titles have been prepared and typed in the
Library, and are now properly filed in the card catalog. These
do not include those cards printed by the Library of Congress
for the publications of the United States Department of Agricul-
ture, which are purchased therefrom.
Every effort is being made to make this an unexcelled agricul-
tural research library. It is of the utmost importance that this
be done, for otherwise those members of the staff conducting
agricultural experiments and investigations will be seriously
handicapped. With this idea in view, the librarian is not only
interested in modern methods for conducting a library, but
equally interested in a study of the literature essential to the
work this institution is carrying on. Research in agricultural
literature, especially that of the tropical and semi-tropical
lands, therefore, has been productive of much good.
Preparing of bibliographies has been an important phase of
work the past year. Several lengthy ones have been undertaken,
while considerable time has been spent on the citrus list. This
now numbers several hundred titles.
The workers in the field have called on the library for numer-
ous loans and references, and many people throughout this and
other states have had occasion to use the valuable material avail-
able here.
Altogether, the year has been a successful one, considered
from the viewpoint of present conditions. Particularly gratify-
ing to the librarian has been the appreciation of the library by
those persons having occasion to use it constantly.


Annual Report, 1928

Wilmon Newell, Director.
SIR: I submit the following report of the Tobacco Experi-
ment Station at Quincy for the fiscal year ending June 30, 1928.
Plant Pathologist in Charge.

The only improvement of permanent nature made during the
year was the erection of a tool shed. The cost of this shed was
approximately $250.

Fertilizer experiments with shade tobacco were resumed this
year on new land. In order to obtain the maximum amount of
practical information, certain changes were made in the original
plan of the experiment.
A standard fertilizer formula was adopted as a basis for com-
parison with other formulae and with other sources of plant
nutrients. This standard fertilizer contains the average amounts
of the three plant nutrients now in use by eight of the largest
growers of shade tobacco in the vicinity of Quincy and the nutri-
ents are derived from the same sources as that used by these
growers. This standard fertilizer contains 275 pounds of am-
monia, 215 pounds of phosphoric acid and 236 pounds of potash
per acre, including the nutrients contained in 10 tons of stable
manure. Eleven other fertilizer combinations are used on the
two acres. The object of the experiment is to determine the best
sources and amounts of the three plant nutrients required to
grow a profitable crop of shade tobacco. Each fertilizer treat-
ment is applied on five plots of 1/30 acre each. The plots are
located on different parts of the field in order to take advantage
of any variation in the soil which may exist.
A resistant type of cigar wrapper tobacco-301-was selected
for the fertilizer tests because it is highly resistant to black
shank and also produces a leaf of good quality. It is impossible
to conduct the experiment for more than one year on the same
piece of land with Connecticut Round Tip or other susceptible