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Cotton varieties for Florida

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Title:
Cotton varieties for Florida
Series Title:
Bulletin - University of Florida Agricultural Experiment Station ; 285
Creator:
Carver, W. A.
Place of Publication:
Gainesville, Fla.
Publisher:
University of Florida Agricultural Experiment Station
Publication Date:
Language:
English

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Subjects / Keywords:
City of Gainesville ( local )
Cotton ( jstor )
Rain ( jstor )
Bolls ( jstor )

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University of Florida
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All applicable rights reserved by the source institution and holding location.

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September, 1935


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








COTTON VARIETIES FOR

FLORIDA


By W. A. CARVER

















Bulletins will be sent free to Florida residents upon application to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


Bulletin 285








EXECUTIVE STAFF

John J. Tigert, M.A., LL.D., President of the
University
Wilmon Newell, D.Sc., Director
H. Harold Hume, M.S., Asst. Dir., Research
Harold Mowry, M.S.A., Asst. Dir., Adm.
J. Francis Cooper, M.S.A., Editor
Jefferson Thomas, Assistant E litor
Clyde Beale, A.B.J., Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager
K. H. Graham, Business Manager
Rachel McQuarrie, Accountant

MAIN STATION, GAINESVILLE

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

ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Animal Husbandman**
R. B. Becker, Ph.D.. Dairy Husbandman
W. M. Neal, Ph.D., Asso. in An. Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Asst. Veterinarian
N. R. Mehrhof, M.Agr., Poultry Husbandman
W. W. Henley, B.S.A., Asst. An. Husbandman
Bradford Knapp, Jr., M.S., Asst. An. Husb.
P. T. Dix Arnold, B.S.A., Assistant Dairy
Husbandman
L. L. Rusoff, M.S, Laboratory Assistant
Jeanette Shaw, M.S., Laboratory Technician

CHEMISTRY AND SOILS
R. W. Ruprecht, Ph.D., Chemist**
R. M. Barnette, Ph.D., Chemist
C. E. Bell, Ph.D., Associate
R. B. French, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant

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

ECONOMICS, HOME
Ouida Davis Abbott, Ph.D., Specialist**
L. W. Gaddum, Ph.D., Biochemist
C. F. Ahmann, Ph.D., Physiologist
L. H. Rogers, M.A., Spectroscopic Analyst

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

HORTICULTURE
A. F. Camp, Ph.D., Horticulturist**
G. H. Blackmon, M.S.A., Horticulturist
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Horticulturist
R. J. Wilmot, M.S.A., Specialist, Fumigation
Research
R. D. Dickey, B.S.A., Assistant Horticulturist

PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist"*
George F. Weber, Ph.D., Plant Pathologist
R. K. Voorhees, M.S., Assistant
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Assistant Botanist


BOARD OF CONTROL

Geo. H. Baldwin, Chairman, Jacksonville
A. H. Blanding, Bartow
A. H. Wagg, West Palm Beach
Oliver J. Semmes, Pensacola
Harry C. Duncan, Tavares
J. T. Diamond, Secretary, Tallahassee

BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY
L. 0. Gratz, Ph.D., Plant Pathologist in
Charge
R. R. Kincaid, Ph.D., Asso. Plant Pathologist
J. D. Warner, M.S., Agronomist
R. M. Crown, B.S.A., Asst. Agronomist
Jesse Reeves, Farm Superintendent

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

EVERGLADES STATION, BELLE GLADE
A. Daane, Ph.D., Agronomist in Charge
R. N. Lobdell, M.S., Entomologist
F'. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane Physiologist
G. R. Townsend, Ph.D., Assistant Plant
Pathologist
J. R. Neller, Ph.D., Biochemist
R. W. Kidder, B.S., Assistant Animal
Husbandman
Ross E. Robertson, B.S., Assistant Chemist

SUB-TROPICAL STATION, HOMESTEAD
H. S. Wolfe, Ph.D., Horticulturist in Charge
W. M. Fifield, M.S., Asst. Horticulturist
Stacy O. Hawkins, M.A., Assistant Plant
Pathologist

W. CENTRAL FLA. STA., BROOKSVILLE
W. F. Ward, M.S.A., Asst. An. Husbandman
in Charge*

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

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









COTTON VARIETIES FOR FLORIDA

By W. A. CARVER

CONTENTS
PACKF
Effect of Soil, Rainfall, and Time of Planting Upon Yield of Lint.................................. 3
Experim ental M ethods ...... .......... ... ...... ... -..--------- ... .. ..... 9
R results of V variety T ests.................... ........................................................... .. ...... 10
Tests of 1925-1929 ...................... ............................ .......... ........ ... .... 10
Tests of 1930-1933 .......... .. .................................. .. 10
Test of Florida-Grown and Out-of-State Cotton Seed.................................... ......... 15
Discussion of Results and Conclusions 1...... ... ..... ... ......................... ... 10
Recommendation of Varieties ...--- .............. ....................... ... ................................ 18
List of Wilt-Resistant and Wilt-Susceptible Varieties of Cotton Tested in Florida............... 19
Suggestions on the Production of Cotton Seed .... ..................- ...... ...... 1.3


INTRODUCTION

The variety of cotton planted is one of the basic factors in
profitable cotton production. Farmers who are unconcerned
about varieties and plant "just cotton" are likely to begin the
season with a handicap which easily could have been avoided.
The Florida Agricultural Extension Service has studied the value
of improved cotton varieties versus common varieties of seed
in the cotton demonstrations planted during a six-year period
(1923-1928). They found that those farmers using improved
seed produced an average of ten percent more seed cotton per
acre than the farmers who planted seed of common varieties.
The Florida Experiment Station has tested the relative value
of 59 different varieties of cotton. The varieties which were
commonly grown in the state and others thought likely to be
adapted to Florida conditions were used in the variety trials.
This bulletin reports the results of these tests for the years
1925-1933.

EFFECT OF SOILS, RAINFALL, AND TIME OF PLANTING
UPON YIELD OF LINT

Most of the cotton produced in Florida is grown in a narrow
strip of territory about 25 to 40 miles wide, extending along
the northern border of the state from Madison County west-
ward. The soil textures best suited for cotton growing are the
sandy loams, fine sands, and medium sands which are well
drained. Those soils used most for cotton have grayish brown
to red surface soils with red subsoils (Orangeburg and Green-
ville series), gray surface soils with yellow subsoils (Norfolk









COTTON VARIETIES FOR FLORIDA

By W. A. CARVER

CONTENTS
PACKF
Effect of Soil, Rainfall, and Time of Planting Upon Yield of Lint.................................. 3
Experim ental M ethods ...... .......... ... ...... ... -..--------- ... .. ..... 9
R results of V variety T ests.................... ........................................................... .. ...... 10
Tests of 1925-1929 ...................... ............................ .......... ........ ... .... 10
Tests of 1930-1933 .......... .. .................................. .. 10
Test of Florida-Grown and Out-of-State Cotton Seed.................................... ......... 15
Discussion of Results and Conclusions 1...... ... ..... ... ......................... ... 10
Recommendation of Varieties ...--- .............. ....................... ... ................................ 18
List of Wilt-Resistant and Wilt-Susceptible Varieties of Cotton Tested in Florida............... 19
Suggestions on the Production of Cotton Seed .... ..................- ...... ...... 1.3


INTRODUCTION

The variety of cotton planted is one of the basic factors in
profitable cotton production. Farmers who are unconcerned
about varieties and plant "just cotton" are likely to begin the
season with a handicap which easily could have been avoided.
The Florida Agricultural Extension Service has studied the value
of improved cotton varieties versus common varieties of seed
in the cotton demonstrations planted during a six-year period
(1923-1928). They found that those farmers using improved
seed produced an average of ten percent more seed cotton per
acre than the farmers who planted seed of common varieties.
The Florida Experiment Station has tested the relative value
of 59 different varieties of cotton. The varieties which were
commonly grown in the state and others thought likely to be
adapted to Florida conditions were used in the variety trials.
This bulletin reports the results of these tests for the years
1925-1933.

EFFECT OF SOILS, RAINFALL, AND TIME OF PLANTING
UPON YIELD OF LINT

Most of the cotton produced in Florida is grown in a narrow
strip of territory about 25 to 40 miles wide, extending along
the northern border of the state from Madison County west-
ward. The soil textures best suited for cotton growing are the
sandy loams, fine sands, and medium sands which are well
drained. Those soils used most for cotton have grayish brown
to red surface soils with red subsoils (Orangeburg and Green-
ville series), gray surface soils with yellow subsoils (Norfolk









COTTON VARIETIES FOR FLORIDA

By W. A. CARVER

CONTENTS
PACKF
Effect of Soil, Rainfall, and Time of Planting Upon Yield of Lint.................................. 3
Experim ental M ethods ...... .......... ... ...... ... -..--------- ... .. ..... 9
R results of V variety T ests.................... ........................................................... .. ...... 10
Tests of 1925-1929 ...................... ............................ .......... ........ ... .... 10
Tests of 1930-1933 .......... .. .................................. .. 10
Test of Florida-Grown and Out-of-State Cotton Seed.................................... ......... 15
Discussion of Results and Conclusions 1...... ... ..... ... ......................... ... 10
Recommendation of Varieties ...--- .............. ....................... ... ................................ 18
List of Wilt-Resistant and Wilt-Susceptible Varieties of Cotton Tested in Florida............... 19
Suggestions on the Production of Cotton Seed .... ..................- ...... ...... 1.3


INTRODUCTION

The variety of cotton planted is one of the basic factors in
profitable cotton production. Farmers who are unconcerned
about varieties and plant "just cotton" are likely to begin the
season with a handicap which easily could have been avoided.
The Florida Agricultural Extension Service has studied the value
of improved cotton varieties versus common varieties of seed
in the cotton demonstrations planted during a six-year period
(1923-1928). They found that those farmers using improved
seed produced an average of ten percent more seed cotton per
acre than the farmers who planted seed of common varieties.
The Florida Experiment Station has tested the relative value
of 59 different varieties of cotton. The varieties which were
commonly grown in the state and others thought likely to be
adapted to Florida conditions were used in the variety trials.
This bulletin reports the results of these tests for the years
1925-1933.

EFFECT OF SOILS, RAINFALL, AND TIME OF PLANTING
UPON YIELD OF LINT

Most of the cotton produced in Florida is grown in a narrow
strip of territory about 25 to 40 miles wide, extending along
the northern border of the state from Madison County west-
ward. The soil textures best suited for cotton growing are the
sandy loams, fine sands, and medium sands which are well
drained. Those soils used most for cotton have grayish brown
to red surface soils with red subsoils (Orangeburg and Green-
ville series), gray surface soils with yellow subsoils (Norfolk






Florida Agricultural Experiment Station


series), grayish-brown pebbly surface soils with yellowish clay
pebbly subsoils (Tifton series), and gray surface soils with pale
yellowish and white splotched subsoils (Blanton series). The
very heavy red clay soils are not well adapted to cotton. Such
soils delay the maturity of the cotton and thus expose it to
excessive weevil damage.
The rainfall by months in the Florida cotton growing section
during the growing season and yield of lint cotton per acre each
year over a 17-year period (1917-1933) are given in Table 1.
The final estimates issued yearly on December first by the crop
reporting board of the Bureau of Agricultural Economics, United
States Department of Agriculture, were used for the state aver-
age yield of lint per acre. The average of the United States
Weather Bureau records at Madison, Tallahassee, Marianna,
DeFuniak Springs, and Cottage Hill was taken for rainfall. The
17-year average rainfall for each month, together with the total
rainfall for the crop year, and the yield of lint per acre for each
year are shown. The coefficient of variability for each of these
measurements is also given for the years 1917-1932. The co-
efficient of variability is a relative measure of variation ex-
pressed in percentage.
In the cotton-growing section of Florida there is a sharp rise
in rainfall during June, the peak being reached in July. From
July, there is a gradual decline extending through November.
As shown in Table 1, the rainfall of April was the most variable
of any month during the season, having a coefficient of varia-
bility of 72 percent. The amount of rain in April averaged
slightly more than either March or May over the 17-year period,
but its rainfall varied more from year to year than either of
these months.
The extreme variability of moisture and temperature condi-
tions during the months of March and April cause considerable
variation in the best time for planting cotton. When warm
weather comes early and there appears to be sufficient moisture
in the soil for prompt germination of seed, early planting seems
desirable. During such years, early plantings (March 20-25)
are better probably because they take advantage of the moisture
from the early spring rains and escape the danger of an un-
favorably dry season for seed germination in April. Since cotton
is a warm-weather plant as well as a dry-weather plant, cold
damp soil with continued cloudy weather should be taken as a
sign to delay planting.
Before cotton plants are up to a uniform stand and thinned






TABLE 1.-SHOWING THE RAINFALL DURING THE COTTON GROWING SEASON IN NORTHWEST FLORIDA AND THE STATE YIELD
OF LINT PER ACRE OVER A 17-YEAR PERIOD, 1917-1933.


Year



1917 .............. .......
1918 ............-........
1919 ............ .........
1920 ................ .......
1921-.... ....... ...... .
19232 .. .. .... ...
1924...................
1925 ... .. ...
1925---- ------.
1926 .... ..........
1927 ... ... ......-..
1928 ... ...............
1929 ........... .
1930 ................
1931..... .... .........
1932................ ..
1933................. .

Average 1917-1933.-

Coef. of var.
1917-1932........-


March


2.46
1.16
5.37
2.45
2.92
5.73
4.38
4.06
1.30
7.10
2.56
7.17
8.65
7.92
4.74
4.08
5.42

4.56


50.22


April


1.51
.8.76
5.32
8.54
4.21
1.98
4.59
4.68
1.49
4.37
0.99
13.18
4.94
2.19
2.16
1.91
11.50

4.84


72.46


May


3.49
3.01
6.12
6.46
5.40
7.01
7.59
3.03
2.41
2.92
1.02
2.90
4.73
1.75
2.26
7.29
1.68

4.06


49.41


Rainfall in Inches

June July A


4.26 7.56
3.98 4.43
3.89 9.11
5.94 6.01
2.71 7.52
8.17 5.26
11.29 6.91
6.95 9.19
4.96 5.77
4.06 7.71
11.33 7.42
6.99 8.00
8.69 9.04
3.29 5.96
3.15 8.06
7.87 5.22
3.51 10.09

5.94 7.25


44.10 2).51


ugust


7.50
8.10
7.36
9.84
5.21
6.01
7.72
3.50
3.40
9.89
4.31
8.89
4.88
2.98
7.43
9.48
6.33

6.64


34.24


The rainfall data are the averages of the U. S. weather records at Madison, Tal'ahassee, Marianna (Blountstown for
August and September 1933), DeFuniak Springs (Bonifay for September 1918; all of 1919 and 1923, and March through
August 1925), and Cottage Hill (Pensacola for 1917 through 1924, and September 1926). The government estimates were
taken for the state average yield of lint per acre.


September


5.43
3.54
2.00
6.51
1.85
4.20
3.23
13.63
2.82
8.06
3.27
7.38
8.08
8.03
2.81
9.39
1.95

5.42


56.21


Total for
Crop
Year

32.21
32.98
39.17
45.75
29.82
38.36
45.71
45.07
22.15
43.91
30.90
54.51
49.11
32.12
30.61
45.24
40.48

38.71


22.12


Pounds
of
Lint
per
Acre


100
85
74
86
80
102
40
130
180
145
126
97
145
200
175
79
134

116.4


37.17






Florida Agricultural Experiment Station


to the desired distance, they are often exposed to the danger
of heavy rains, cold, cloudy days, cutworms, blowing sand, and
seedling diseases. By planting on slightly elevated, level-top
seedbeds, damage from heavy rains, blowing sand, and cold
weather may be reduced. Damage to the seedlings from cut-
worms and damping off, which is usually more severe during
cool, damp weather, may be lessened by delayed planting.
May is the month in which the heavy crop of early squares
is formed. During the 17-year period studied, this month had
an average rainfall of 4.06 inches, which was slightly less than
that for any other month of the cotton season. Its variability
also decreased as compared with the two previous months. The
cotton blooming period begins about the middle of June. During
June the rainfall increases in amount and regularity. This trend
continues into the month of July. Table 1 shows for July an
average rainfall of 7.25 inches and a variability coefficient of
only 20.51 percent. Most of the cotton bolls are set during the
period from June 15 to July 20. As a general rule the squares
and bolls which form after July 20 have small chance of escaping
destruction by the boll weevil.
The rainfall decreases in amount and its variability increases
through August and September. The harvest season, which
extends from about the middle of August to the middle of Sep-
tember, does not escape injurious rain. Sunshine usually follows
closely after the rains and the time that cotton is too wet to
harvest is relatively short. At the same time, there is need of
greater precaution against picking cotton when it is wet with
rain or dew. Picking and storing wet cotton may result in
damage to both lint and seed.
The curves shown in Figures 1 and 2 were plotted from the
data given in Table 1. These curves are used in order to show
more clearly some of the relations that exist between rainfall
and yield of cotton.
In Figure 1 the solid line represents the rainfall in inches for
the month of May over a 17-year period while the broken line
represents the yield of lint per acre for corresponding years.
The yields are plotted in the order of their magnitude. The
lowest yield, 40 pounds, is shown as the lowest point at the left
end of the broken line; and the highest yield, 200 pounds, is
shown as the highest point at the right end of the line. The
other yields lie in order of their magnitude between these two
extremes. Then the rainfall for each year is plotted opposite
the yield for that year. For example, it is shown in Table 1






Cotton Varieties for Florida


7.4- / -200
Rainfall -
6.6- -ISO

:5.8- / -I60
S/eld
S5.0- \ -I(O


&14., -120 $3
'34- I / ~.




2.6- so" -80

1.S- / /V -60
/ Yield 6
I.0- -0

1923119'32 2I Ig,20,2g I7'22027 24'33126'29131'25'30
Years 1917-1933 arranged in order of ascending yields
Fig. 1.-Curves showing the rainfall in inches during the month of May
and the yield of lint cotton per acre during the 17-year period 1917-1933.
Based on figures in Table 1.
that the lowest yield, 40 pounds, occurred in 1923 and that the
rainfall in May of that year was 7.59 inches. Therefore, the
rainfall of 7.59 inches is plotted in the rainfall curve opposite
the yield of 40 pounds in the yield curve. In like manner, the
rainfall in May for each of the other years is plotted opposite the
yield for that year.
It happened that the highest rainfall of May was associated
with the lowest yield of cotton during the 17-year period, and
that the highest yield was associated with the third from lowest
rainfall. In fact, the general direction of the two curves in
Figure 1 shows a decided tendency for low yields to be associated
with high rainfall and for high yields to be associated with low
rainfall. Heavy rainfall during the month of May appears to
have a greater influence in reducing the yield of cotton than
that of any other month. However, certain other months show
the same tendency and contribute their influence in the same
direction as does the May rainfall. These months, as shown by







Florida Agricultural Experiment Station


correlation studies, are April, June, and August. The last month
apparently has a greater detrimental influence than April or
June. Cool weather usually is associated with the April rains,
and the consequent dying off of young plants results in a low
yield of cotton. The rapid increase of weeds and boll weevil
infestation during a rainy May is perhaps the major cause of
injury to the crop during that month. The rainfall of July
averages the heaviest of any month during the season and is
also the most constant from year to year; thus it no doubt exacts
a heavy toll in cutting the yield of cotton every year. A heavy
rainfall in August maintains weevil infestation at a high level
and encourages the rotting of bolls.

54- AI 200

50- -ISO
f
S Rainfall /
2- / -1460
4P4

aI \ / "o

42- 12- 0


0
S30- 0- so

26- bO
/ Yield

22- 40
a I I i i I I aI I I I | I I
1923' I9'32 2IIIS820128117122 27124133'26'29'3I'25'30
Years 1917-1933 arranged in order of ascending yields
Fig. 2.-Curves showing the seasonal (March-September) rainfall in
inches and the yield of lint per acre during the 17-year period 1917-1933.
Based on figures in Table 1.

Figure 2 gives curves showing the total rainfall in inches
during the cotton growing season, or from March to September
inclusive, and yield of lint per acre over the 17-year period. The
curves are based on the data given in Table 1 and are plotted
by the same method as that used for the curves in Figure 1.






Cotton Varieties for Florida


A general tendency for low yields in rainy years and high yields
in dry years is shown by the curves. Still, this tendency is not
so marked as that shown by the curve for the May rainfall.
The total rainfall for the month or the year does not show
the influence of certain factors which may at times be associ-
ated with rainfall. For example, the lowered temperatures ac-
companying rains are unfavorable to the growth of cotton. This
is especially true of the early spring rains. Likewise, the total
rainfall of a spring month may be low, but one torrent of rain
may have fallen over a large area during that month to leach
practically all of the fertilizer from sandy soils and result in a
low yield of cotton for the state.
EXPERIMENTAL METHODS
Cotton variety tests for Florida were conducted on the Main
Experiment Station farms at Gainesville during the seasons
1925-1930 and at the North Florida Experiment Station at
Quincy during the years 1931-1933. Cooperative variety tests
were also conducted with farmers assisted by county agents in
one or more counties in North and West Florida each season
with the exception of 1925 and 1933.
The experiments were located on the better grades of Norfolk,
Tifton, and Orangeburg soils, which are typical of the soils
generally planted to cotton. During the years of 1925 to 1929
inclusive, each variety was first planted in single-row plots for
one or two years and studied carefully to determine its possible
adaptation to Florida conditions. A variety which appeared
promising in these trials was then tested competitively with
several other varieties in larger tests. Single-row plots were
used very little after 1929. Fewer new varieties were imported,
and these were generally tested directly in replicated plots along
with previously tested varieties. In the tests having replicated
plots, which were conducted on the Experiment Station farms,
each variety was planted either in three 4-row plots 372 feet long,
or in four 3-row plots 90 to 100 feet long, or in three 3-row plots
50 feet long. The latter small area was used only in 1933. In
the cooperative experiments with growers the size of plots and
number of replications varied considerably. Most of them con-
sisted of two 2-row plots averaging 220 feet in length.
Variety samples of seed cotton were gathered from the local
test each year and from one or more of the cooperative tests.
A sample of 50 bolls was gathered from each variety at the
second picking. The samples were ginned locally on a small






Florida Agricultural Experiment Station


roller type gin. The data on grade of lint, the staple length,
and the price of lint per pound for each sample were furnished
by the Board of Review Examiners, U. S. Department of Agri-
culture, Bureau of Agricultural Economics, Washington, D. C.

RESULTS OF VARIETY TESTS
TESTS OF 1925-1929
Forty-two cotton varieties were placed in the preliminary
trials of 1925 through 1929 (Table 2). These varieties were
grown in observation plots during the first year of trial. Each
variety was studied carefully to determine its adaptability to
Florida conditions. The varieties which appeared best adapted
were tested further in plots designed to give more conclusive
results on their yielding ability. Some varieties were tested
only one year; others were tested two, three, or all five years.
Those varieties which appeared poorly adapted to Florida con-
ditions were planted in the tests only one year. However, certain
varieties which are listed in the table as being tested only one
or two years appear in the tests of the following years as shown
in Tables 3 and 4, and will be discussed later. The order in which
the varieties are listed in Table 2 shows their approximate yield-
ing ability. Rhyne's Cook, Acala 31, Cook 307-6, Council Toole,
Lightning Express, Bottoms, Trice, and Cleveland 54 were the
eight most productive varieties.
The third column of the table gives the number of years each
variety was planted, either in single-row observation plots or in
replicated plot tests. Other data given on the varieties are:
percent and length of lint; degree of resistance to wilt, or black
root as it is sometimes called; earliness in maturity; and size
of boll expressed in the number of bolls required to make one
pound of seed cotton. The degree of resistance to wilt was
estimated from plant counts which were made in the plots of
the variety tests. A complete list of the wilt-resistant and wilt-
susceptible cotton varieties tested during the years 1925-1933
is given in Table 5. Earliness in maturity was taken from the
percentage of the total crop which was harvested at the first
picking. A study of the variety characters shown in Table 2
will give the reader a fair idea of how the varieties performed
in Florida.
TESTS OF 1930-1933
The varieties which appeared most promising in previous
tests, together with several new varieties, were included in the







Cotton Varieties for Florida


TABLE 2.-GENERAL SUMMARY OF CHARACTERS OF THE COTTON VARIETIES USED IN THE
VARIETY TESTS DURING THE YEARS 1925-1929.
SLength Bolls
Order of Number Per- of Comparative per
VARIETY IEstimated of cent Lint in Resistance Earliness I Pound
Yield Years Lint 1/32 to Wilt or Seed
Tested Inch Black Root Cotton

Rhyne's Cook.....-.......-......... 1 2 33 26 High Med. 77
Acala 31............................. 2 2 36 33 Med. Early 75
Cook 307-6.......................... 3 5 34 25 High Med. 85
Council Toole .................. 4 3 33 28 High Med. 100
Lightning Express............. 5 5 30 34 High Early 87
Bottoms-.................... ........ 6 6 2 34 26 Low Med. 93
Trice-Miss. Sta..........---...........-- 7 3 32 29 Low Early 88
Cleveland 54......................... 8 2 35 28 Med. Med. 79
Express 95............................ 9 2 33 33 Low Med. 85
Mexican..................--- ........- ... 10 3 33 30 Med. Med. 72
College No. 1.......-................ 11 1 33 28 Low Early 81
Miller.....----------............................ 12 3 33 29 High Med. 65
Petty Toole........................... 13 1 34 26 High Early 93
Perry Toole----........................... 14 1 36 26 High Med. 92
King 29...........................--- ..... 15 3 33 26 Low Early 108
Express 432........................... 16 1 32 36 Med. Early 84
Express 116.......................... 17 1 32 33 'Low Early 74
Piedmont Cleveland............ 18 1 32 26 Low Med. 73
Rowden 40............................. 19 2 34 30 Med. Med. 65
Rowden 2119 -------....................... 20 1 35 30 Med. Med. 66
Coker Cleveland 3 & 6----.... 21 3 36 30 Low Med. 85
Wilt Resistant
Long Staple...................... 22 1 36 34 High Early 88

Dixie Triumph, Watson...... 23 3 34 26 High Late 85
W hiting................................. 24 1 34 26 Low Med. 95
Lewis 63, Statham........----.... 25 1 32 26 High Med. 108
Mathis Toole.--.................... 23 1 38 26 High Med. 110
Cook, Improved.................... 27 1 34 26 Low Early 86
Wannamaker Cleveland...... 28 2 37 26 Low Late 77
Super Seven.......................... 29 1 33 34 High Med. 81
Covington Toole.................. 30 3 33 27 High Med. 87
Delta & Pine Land No. 5..... 31 1 33 28 Med. Med. 82
Carolina Foster........ .......... 32 1 32 36 Low Med. 84
Chappell ................................ 33 1 38 30 Low Early 64
Trice 321-- ---....... ----....................... 34 1 35 30 Low Early 107
Salsbury .......................... 35 1 33 34 Low Early 84
Delta Type Webber----....... 36 1 31 36 Low Med. 85
Webber 49 ........................... 37 1 35 38 Low Med. 98
Coker Foster.------- ...... 38 1 34 34 Low Med. 85
Wannamaker Cleveland
Wilt Resistant.................. 39 1 30 22 High Med. 95

Wilds No. 2.......................... 40 1 29 40 Low Med. 71
Hartsville--................. 41 1 32 34 Low Med. 77
Neely Cleveland..-................ 42 1 35 30 Low Med. 79




TABLE 3.-COTTON VARIETY TEST IN FLORIDA DURING THE SEASONS 1930-1933. THE YIELD Is GIVEN IN POUNDS OF LINT
PER ACRE, AND THE VALUE OF LINT AND SEED IN DOLLARS PER ACRE.


VARIETY

Clevew ilt.............................
Rhyne's Cook.......................
Misdel No. 2-.................
Cook 144..-..........................--
Express 121.........................
Farm Relief .........................
Lewis 63, Kirkland.............
Misdel No. 1................
Council Toole........ .........
Trice, Miss. Sta...................
Lightning Express ............
Wilson Type......................
Acala 31..---... .........
Petty Toole---......... --.
Cleveland 54................
Chappell--........- ---..-.....
Covington Toole..................
Sikes-...... ...
M iller ---- ... .......
Cook 27-54 .......... .....-...
Arkansas No. 17...............
Cook 307-92... ......................
Bottoms...........-.............
Dixie Triumph, Marett......
Heavyfruiter.........................
Super Seven-....................
Cook 307-6.......................
Rowden 40 ...........................
Wannamaker Cleveland......
Dixie No. 14..........................
Tidewater........................
Coker Cleveland 884...........


Number
of
Years
Tested

3
4
2
1
1
1
2
2
4
2
4
2
3
3
3
2
3
2
2
1
1
1
2
1
2
1
1
2
1
1
1
1


Test of 1930
Yield Value
lbs. Dollars


359 43.26
334 45.09


304
261



310

285



. .


38.86
34.55
37.50
32.68
37.74
40.00
32.98
36.90
36U39

36.31
33.46



38.39

35.32


Test of 1931 Test of 1932 Test of 1933
Yield Value Yield Value Yield Value
lbs. Dollars lbs. Dollars lbs. Dollars

248 19.51 213 18.61 320 40.32
272 16.48 260 21.79 327 34.37
183 15.51 --. .......... ...- ---- ....
--- ---. ... .......... 312 38.31
214 18.43 ...... ......... ...... ..........
215 18.27 ..... .......... ... ....-
---... 211 17.63 333 38.27
196 16.78 .. .. .-
275 19.79 195 16.99 329 37.74
207 17.19 ...... .......... -.........
211 18.69 167 15.94 299 40.69
247 16.82 ..... ........ .. ...
212 16.67 164 15.89 ... .. .
252 17.05 202 17.51 .... ..
227 16.07 188 16.18 ... .......
237 15.07 ...... .......... -- --....
221 14.27 203 17.08 296 36.69
223 14.73 ...... .......... ..... ......
221 15.54 ... .......... .......... ----
------- ... ... ... -..... 284 32.61
......... 164 15.80 .. ----.
...... .--..- 284 32.47
191 12.35 ..... .......... .... .... ....
........ ..... .......... 280 32.25
193 13.12 .... ...................
183 14.92 ..... ........ ...... ..--
224 14.61 ....- -- ...... ...-- ........
199 14.34 165 14.24 ......-
218 14.00 ...... ........- --...... ..........
207 13.74 -.- ..... .. .......
... ......... 136 13.27 .......
171 13.30 ...... .......... .... ..........


not tested each year were corrected so that all varieties may be compared directly.


Averages1


Rank


I bs. | Rank

269 4A
305 1
251 8A
263 5A
227 21
228 20
277 2
233 17
269 4B
241 11
229 19
271 3
237 14A
258 7
251 8B
263 5B
248 9
259 6
238 13
239 12A
212 23A
239 12B
244 10
236 15
234 16
194 24
237 14B
212 23B
231 18
219 22
176 26
181 25


Value
Dollars

29.22
28.98
28.75
28.28
27.92
27.67
27.53
27.36
27.27
27.14
27.00
26.97
26.53
25.78
25.59
25.14
24.89
24.84
24.36
24.06
24.03
23.98
23.81
23.81
23.25
22.59
22.14
21.70
21.20
20.18
20.17
20.15


iThe data of those varieties which were




TABLE 4.-CONTINUATION OF TABLE 3. SUMMARY OF DATA1 TAKEN ON
1932, AND 1933 ONLY.


VARIETY CHARACTERS DURING THE SEASONS 1961,


VARIETY


C evew ilt ... ...... ...... ..........
Rhyne's Cook............................ ...
M isdel N o. 2............................ ......
Cook 144-........................ ... ....
Express 121...........-......--........
Farm Relief................... .. ..... ....
Lewis 63, Kirkland.........-- ............
M isdel N o. 1........................ ........
Council Toole.................. ............
Trice, Miss. Sta..........- .................
Lightning Express..........................
Wilson Type...........................
Acala 31............................
Petty Toole...........----...... ....... ...
Cleveland 54 ....... .............................
Chappell......................... ......
Covington Toole................-.........
Sikes........... ........ ... ...... ..........
M iller........... ...-..- .. .. .......
Cook 27-54.................... .........
Arkansas No. 17... ........... ..........
Cook 307-92.......----.........-- ........
Bottom s..... ........ ..........................- ....
Dixie Triumph, Marett ...................
V andiver...............................
Super-Seven......... .. ........ .....
Cook 307-6....................... ...
Rowden 40.................... ....--...-.......
Wannamaker Cleveland-....................
Dixie No. 14....... .................
Tidewater........................ ..
Coker Cleveland 884..---.............--....


Percent

S36
36
32
34
34
36
36
33
33
31
32
34
34
34
36
36
S34
S35
37
36
33
37
S35
35
34
.. 35
S37
.. 34
. 36
. 36
. 32
35


Length
in
1/32nd
Inches
33
28
36
32
36
35
29
36
30
34
35
29
34
28
30
27
29
27
31
30
33
30
29
30
29
35
30
31
21
29
37
33


LINT DATA
Grade2 in
Relative
Numerical
Values
3.69
4.39
4.02
3.35
4.70
3.01
3.83
4.70
3.56
3.38
3.78
5.03
4.17
3.83
4.03
4.02
4.10
4.02
3.35
3.35
3.70
3.35
4.35
3.35
4.35
3.01
3.35
4.17
4.35
3.69
4.17
3.69


Value
per
Pound,
Cents
8.53
7.17
9.24
8.34
9.51
9.21
7.68
9.39
7.80
8.63
9.11
6.91
8.48
7.51
7.70
6.71
7.64
6.91
7.78
7.82
8.80
7.82
6.93
7.82
7.12
8.96
7.40
7.95
6.50
7.22
10.33
8.47


Percent
Harvested
at 1st
Picking

30
29
52
42
37
44
41
49
40
53
50
46
50
40
45
44
31
35
39
31
49
45
60
30
43
44
36
47
36
33
37
37


Bolls
Resistance per
to Wilt, Pound
Estimated Seed
Cotton

High 84
High 72
Low 92
High 87
Med. 82
Low 72
High 81
Low 77
High 102
Low 89
High 89
Med. 77
Med. 78
High 89
Med. 76
Med. 86
High 83
Med. 81
High 64
High 87
Med. 81
High 81
Low 92
High 85
Low 81
High 98
High 91
Med. 67
Low 76
High 82
Med. 64
Low 82


1The varieties which were not tested each year were corrected so that all varieties may be compared directly.
2In calculating the grade values, grades were given values as follows: Good Middling 3, Strict Middling 4, Middling and
Strict Middling spotted 6, and Good Middling spotted 5. Hence, the smaller number indicates the higher grade.






Florida Agricultural Experiment Station


tests of 1930. The new varieties tested were Wilson Type, Sikes,
Heavyfruiter, Misdel No. 1, and Misdel No. 2. In the 1931 tests,
the new varieties were Dixie No. 14, Coker Cleveland 885, Cleve-
wilt, Farm Relief, and Express 121. After 1931, most of the
varieties which were not bred for planting on wilt-infested land
were dropped from the tests. This was done because of the
apparent growing need for wilt-resistant varieties and because
high yielding resistant varieties had been found. In 1932, the
new varieties tested were Kirkland's Lewis 63, Arkansas No.
17, and Tidewater. Tidewater had been planted in a small dem-
onstration plot during the previous season. This variety is a
selection from Acala. The new varieties tested in 1933 were
Cook 27-54, Cook 307-92, Cook 144, and Marett's Dixie Triumph.
A summary of the lint cotton yields and values per acre for
the different varieties tested during the seasons 1930-1933 is
presented in Table 3. The number of years each variety was
tested is shown in the second column. The yield is given in
pounds of lint per acre, and the value of lint and seed is given
in dollars per acre. The data on those varieties which were not
tested during each of the four years were corrected so that all
varieties may be compared directly. The corrected figures for
yield and value appear in the columns headed "Averages".
The corrections for yield, for example, were made by the
method described below. The varieties Rhyne's Cook, Council
Toole, and Lightning Express are the only ones which were
tested every year of the period 1930-1933. So the average yield
of these three varieties each year was used as a "standard".
Then for any given year, the variety yield to be corrected was
divided by this "standard" value for that year. If the variety
to be corrected yielded more than the standard, its "rating"
would be greater than 1.000, say 1.125 for example. If it yielded
less, its rating would be less than 1.000. The given variety's
ratings for the different years tested were then added and this
sum divided by the number of years, giving its average rating.
Then this average rating was multiplied by the average yield of
the three standard varieties during the same seasons. The
resulting number is the corrected yield for the variety in ques-
tion. Corrections for value and other characters were made in
a similar manner.
In Table 3, the varieties are listed in order of value, the nine
most valuable varieties in order being Clevewilt, Rhyne's Cook,






Cotton Varieties for Florida


Misdel No. 2, Cook 144, Express 121, Farm Relief, Kirkland's
Lewis 63, Misdel No. 1, and Council Toole. In calculating value
per acre, the longer stapled varieties were given the advantage
of the higher market price of their lint. The nine highest yield-
ing ones were Rhyne's Cook, Kirkland's Lewis 63, Wilson Type,
Clevewilt, Council Toole, Cook 144, Chappell, Sikes and Petty
Toole. The number of years that each variety has been tested
should be kept in mind when comparing the varieties for yielding
ability and value. The yield from one year's test means very
little.
Other variety characters which are reported in Table 4 are:
percentage, length, grade, and cents per pound of lint; earliness
or percentage of the total crop harvested at the first picking;
estimated resistance to wilt; and size of boll or the number of
bolls required to produce one pound of seed cotton. The lint
grades are expressed in relative numerical values. The different
grades of lint and their assigned values, based on their market
price per pound, are as follows: Good Middling 3, Strict Middling
4, Good Middling spotted 5, and Middling together with Strict
Middling spotted 6. Good Middling (value of 3) was the highest
grade and brought the highest price. Middling and Strict Mid-
dling spotted (grade 6) were the poorest in grade and lowest
in value. Hence, the smaller number indicates the higher grade
of lint. The estimates on resistance to wilt were obtained as
described above for the preliminary tests. No uniformly wilt-
infected soil was available to use for wilt tests. The degree of
resistance shown by the different varieties was rated as high,
medium, or low.

TEST OF FLORIDA-GROWN AND OUT-OF-STATE
COTTON SEED
Seed stocks of cotton varieties produced on the Florida Ex-
periment Station farms and on the farms of Florida farmers
were tested during the seasons 1928, 1930, 1931, 1932, and 1933
in competition with seed stocks of the same variety produced by
seed concerns in other cotton states. A total of 17 different varie-
ties were tested, from three to 10 varieties being tested each sea-
son. The seed stocks produced out of the state excelled stocks
from the same varieties grown in Florida by an average of 56
pounds of seed cotton per acre or a difference of 8.05 percent.
This difference in yield is significant, the odds being 25.3 : 1. A






Florida Agricultural Experiment Station


second parallel experiment using seed stocks of Lightning Ex-
press only and extending over two seasons, 1931 and 1932,
produced similar results. South Carolina seed, produced at the
Sand Hill Experiment Station, Columbia, South Carolina, excelled
Florida-grown seed in yield by 53 pounds of seed cotton per
acre or 9.2 percent. In both experiments, out-of-state seed ex-
celled Florida-grown seed by an average of 10 to 15 percent in
germination.
A study of individual varieties in the first experiment men-
tioned above reveals some differences in the response of certain
varieties to Florida conditions. Of those varieties which have
yielded well in the Florida variety tests, Rhyne's Cook was
planted in the experiment during four seasons, Lightning Ex-
press during three seasons, Council Toole during two seasons,
and Clevewilt during three seasons. The Florida-grown seed of
Rhyne's Cook excelled its imported seed by 58 pounds of seed
cotton per acre, or by 7.4 percent. Lightning Express, to the
contrary, yielded 53 pounds more (6.4 percent) from out-of-state
seed; Council Toole yielded 47 pounds more (7.2 percent) from
out-of-state seed; and Clevewilt yielded 115 pounds more (14.0
percent) from out-of-state seed. Hence, of those varieties
appearing best adapted to Florida, only Rhyne's Cook promises to
produce as good or better planting seed in Florida as in the
section where it originated.

DISCUSSION OF RESULTS AND CONCLUSIONS

The prevalence of cotton wilt or black root, Fusarium vasin-
fectum Atkinson, and the heavy rainfall during the fruiting and
harvesting seasons render many varieties unsuitable for growing
in Florida. Only highly resistant varieties can be planted in
Florida with the assurance of continued satisfactory yields. In
Tables 2 and 4, those varieties rated as having medium resistance
would perhaps continue to produce well on land having a low
wilt infestation, provided cotton were planted in rotation with
other crops that are not attacked by the wilt organism. Varieties
having low resistance are of still more doubtful value. Since
high yielding resistant varieties are available, it appears best
that they be grown in Florida in preference to the less resistant
ones. A list of the wilt-resistant varieties which have been
tested in Florida is shown in the first part of Table 5.






Cotton Varieties for Florida


The varieties found best adapted to Florida conditions have
come from South Carolina, Georgia, and Alabama. Mexican
was the best North Carolina variety tried. Mexican and King
29 from North Carolina were dropped from the tests because
other varieties produced nearer at hand appeared to be as well
or better adapted. Misdel No. 1, Misdel No. 2, Express 121,
Trice, and Cleveland 54 were the most valuable varieties from
Mississippi. The Misdels and Trice have low resistance to wilt,
while Express 121 and Cleveland 54 have a medium degree of
resistance. Miller is the most resistant variety from Mississippi.
However, it has not produced a high yield in the tests and its
bolls do not open well under Florida conditions. The varieties
Wilson Type, Acala 31, Arkansas No. 17 and Rowden 40, which
are produced in Arkansas, have a medium degree of resistance
to wilt, but suffered greater damage from boll rots than the
average of the varieties in the test at Quincy in 1932. Wilson
Type, which was not tested that year, has yielded well in Florida,
but has not done well on wilt-infested soil. It was not noticeably
affected by boll rots during the two years in which it was tested.
Tidewater, a selection from Acala produced in South Carolina,
was injured by boll rots about equally with Acala. The tendency
toward boll rotting appears to result from the bolls not opening
well. In Florida, frequent rains and a warm, humid atmosphere
encourage the growth of boll-rot organisms. Varieties having an
open type of plant, which admits the sunlight, and a medium
sized boll that opens rapidly and well are as a rule relatively
free of boll rots. However, there are no doubt other internal
or external qualities of the plant that influence the tendency
toward boll rotting. Rhyne's Cook, an Alabama variety, ranks
among those most resistant to wilt. It also stands high in the
larger boll group in freedom from boll rots. In the test of
Florida-grown and out-of-state planting seed, Rhyne's Cook pro-
duced a higher yield of cotton from Florida-grown seed than
any of the other varieties which yield well in Florida. Council
Toole from Georgia and Clevewilt and Lightning Express from
South Carolina belong to the small boll group and have a desir-
able type of plant. Clevewilt and Lightning Express are injured
less by boll rots than any of the others. They have small leaves
and an open type of branching which allows the sunlight to reach
many bolls. The heat and drying effect of the sun tend to con-






Florida Agricultural Experiment Station


trol boll rot, and to some extent control the boll weevil by drying
up the small squares which contain young weevils.
The ability of a variety to start fruiting early is of less import-
ance than the ability to fruit rapidly and to maintain a vigorous
growing condition. At the same time, very late varieties must
be avoided as they are often subject to severe damage by boll
weevils which migrate from earlier fields of cotton. It has been
observed that in general those varieties which begin fruiting
very early are lacking in vigor. During the unfavorable fruiting
seasons they are injured more than the vigorous-growing later
varieties, and often fail to resume fruiting when favorable
weather returns. Varieties of medium early maturity have
yielded highest.

RECOMMENDED VARIETIES
The variety type which has proved most profitable in the
variety tests and which is most acceptable to Florida farmers
has the following good characters: (1) high yield of lint per
acre; (2) resistance to wilt or black root; (3) freedom from boll
rots; (4) small to medium size bolls that are easy to harvest;
(5) medium early in maturity; (6) high germinating seed; (7)
vigor of growth in the seedling state and (8) ability to remain
in a vigorous growing condition through the fruiting season.
The varieties which are recommended for general planting in
Florida combine several of these characters. The recommended
varieties listed in order of their value are Clevewilt and Rhyne's
Cook. In calculating variety values, the superior lint length of
Clevewilt was given the benefit of its higher market price. Dur-
ing the period of the test, Rhyne's Cook excelled Clevewilt in
yield by an average of 36 pounds of lint per acre. The lint of
Clevewilt is superior in quality and value to that of Rhyne's Cook
and is generally in greater demand. However, Rhyne's Cook is
more valuable to the grower unless he is able to secure the pre-
vailing higher market price for the Clevewilt lint.
Any variety of cotton can be handled to the best advantage if
it is grown on a large area, as on several adjacent farms. This
is especially true of varieties having superior staple length. By
excluding from this area all varieties except the superior stapled
one, a pure stock of planting seed can be more easily maintained
and a large quantity of uniform staple produced. Consequently,
a higher price can be secured for the lint.







Cotton Varieties for Florida


TABLE 5.-LIST OF WILT-RESISTANT AND WILT-SUSCEPTIBLE COTTON
VARIETIES TESTED IN FLORIDA DURING THE YEARS 1925-1933.

Wilt-Resistant Varieties

Cleveland, Wannamaker Lewis 63, Statham
Wilt Resistant Lewis 63, Kirkland
Clevewilt Lightning Express
Cook 307-6 Miller
Cook 144 Super Seven
Cook 307-92 Toole, Council
Cook, Rhyne Toole, Covington
Cook 27-54 Toole, Mathis
Dixie Triumph, Watson Toole, Perry
Dixie Triumph, Marett Toole, Petty
Dixie No. 14 Wilt Resistant Long Staple

Wilt-Susceptible Varieties


"Acala 31
*Arkansas No. 17
Bottoms
*Chappell
Cleveland, Coker 3 and 6
*Cleveland 54
Cleveland, Coker 884
Cleveland, Neely
Cleveland, Piedmont
Cleveland, Wannamaker
College No. 1
Cook Improved
*Delta Pine Land No. 5
Express 95
Express 116
*Express 121
*Express 432
Farm Relief
Foster, Carolina


Foster, Coker
Hartsville
Heavyfruiter
King 29
*Mexican
Misdel No. 1 and No. 2
*Rowden 40
*Rowden 2119
Salsbury
*Sikes
*Tidewater
Trice, Miss. Sta.
Trice 321
Webber 49
Webber, Deltatype
Whiting
Wilds No. 2
*Wilson Type


*These varieties possess a "medium" degree of resistance to wilt. The
other varieties in this same group have "low" resistance. All of the varieties
listed above under the heading, "Wilt-Resistant Varieties" have a "high"
degree of resistance to wilt.

SUGGESTIONS ON THE PRODUCTION OF COTTON SEED

The following suggestions are given for Florida farmers and
seedsmen who wish to maintain the purity of their cotton varie-
ties and to grow seed of high germinating ability and vigor:
Planting.-The cotton field should not be extremely rich in
organic matter, such as plowed-under legumes. Neither should
an excess of inorganic nitrogen in relation to potash and phos-
phoric acid be present in the soil when the crop is maturing. An
excess of nitrogen encourages vegetative growth at the expense
of seed development.






Florida Agricultural Experiment Station


Plant about 500 yards from other fields planted to a different
variety of cotton in order to lessen the danger of variety cross-
pollination by insects. This barrier would be more efficient if
corn, sorghum, or trees were growing on it. However, the field
should not be closed in and protected from free movement of
air. Such a condition may result in severe boll rotting.
Slightly elevated, open fields of average fertility are favorable
to good seed production. Make the distance between the rows
and between the plants along the row in accord with the fertility
of the land or with the expected size of the plants at maturity.
The spacing should be such that the sun can penetrate a good
distance through the branches between plants and reach the
ground between rows. Thus, ample sunlight may reduce boll or
seed rotting and boll weevil damage.
Roguing.-Fields should be rogued of undesirable plants just
before blooming time and again before harvest; all plants should
be removed which are conspicuously offtype in plant or boll
characters. This is necessary because of the almost unavoidable
variety mixing in the field and at the gin and because of throw-
backs of undesirable types.
Harvesting and Storing Seed Cotton.-Make the first picking
when about one-third of the total crop has opened, and make
other pickings at 7- to 14-day intervals, depending upon the
rapidity of opening. If avoidable, do not pick cotton when it is
wet with dew or rain. If it is picked wet, do not store in this
condition. Spread it out in a thin layer until the locks become
dry and fluffy. Do not pick green cotton from partly opened
bolls, or compact locks which are dark or yellow stained. Un-
weathered cotton from sound, well matured bolls of the first and
second picking may be harvested for planting seed.
Store the seed cotton in a dry room on a dry floor. Cracks of
about one-quarter inch between each plank of the floor and walls
are an aid to drying the cotton. Do not pack the cotton.
Examine it frequently for any sign of heating and if found
to heat, turn it over with a pitchfork.
Ginning.-In saving pure seed at the gin, it is usually advis-
able to wait until the rush of the ginning season is over. The
common practice of saving the latter half of the seed from a
bale-load of seed cotton for planting seed results in much variety
mixing in the gin. Several bales of the same variety must be
ginned in succession in order to remove all seed cotton and seed






Cotton Varieties for Florida


of a formerly ginned bale from the different conveyors. Take
extraordinary precaution to prevent foreign seed from getting
into and contaminating the supply of pure seed.
The rules are as follows:
Remove the seed from the gin roll and thoroughly clean the
gin stand and adjoining parts and the floor of foreign seed and
seed cotton. Dump the seed cotton on to the feeding belt or gin
stand and feed it into the gin roll by hand. Allow the seed to fall
from the roll to the floor in front of the gin stand. Place im-
mediately in sacks which are free of foreign seed, label each sack
inside and outside with tags. Write the following on each tag:
variety name, grower's name, year grown, and the serial number
of the sack.
Storing Seed.-Store the seed in a dry, well-ventilated room.
Stack the sacks of seed in two-sack layers crosswise one another,
leaving air spaces between sacks. If observed to heat, move the
sacks and restack.
Testing Viability of the Seed.-Examine the-seed for germinat-
ing ability some time during the winter months. Several sacks
should be examined, or a sufficient number to give a good idea
of the whole lot. Secure a handful of the seed from the center
of a sack. Note the number of the sack from which seed is
taken. Count out 100 seed, taking care to avoid choosing the
best looking ones. With a knife, cut each of the 100 seed in half
and examine the germ. Discard those seed which are poorly
developed, badly shrunken, or have brown-colored germs. A
count of the seed left from the original 100 will give a fair idea
of the percentage of live seed.
If a germination test by sprouting is wanted and no regular
seed germinator is available, the following method may be used.
Wet 100 seed thoroughly with warm water. Spread them out on
a half folder of newspaper which has also been wet with warm
water. Using a lead pencil, number the paper with the serial
number of the sack from which the seed came. Then roll the
paper over the seed, making a loose roll about 2 inches in
diameter. Place the roll in a shallow pan. Keep the seed roll
moist, wetting with warm water. Cotton seed will germinte
well at the temperature of a living room. The pan should not
be placed directly on the floor as the cold will penetrate to the
seed. Examine the seed every 3 days, removing and counting
those seed which have sprouted. All live seed should sprout in
6 to 9 days.






22 Florida Agricultural Experiment Station

ACKNOWLEDGMENTS
The writer is indebted to Dr. A. F. Camp for starting the
cotton variety work, and for his continued interest and guid-
ance during the years 1925 through 1930. After the season of
1930, the Cotton Department was discontinued and the cotton
work was transferred from Gainesville to the North Florida
Experiment Station at Quincy. The writer wishes to acknowl-
edge his indebtedness to Prof. W. E. Stokes, Head of the Agro-
nomy Department; to Dr. L. O. Gratz, in charge of the North
Florida Experiment Station, for many helpful suggestions; and
to Mr. R. M. Crown, Assistant Agronomist, for valuable assist-
ance in conducting the local variety tests. Grateful acknowledg-
ment is also made to the county agents who aided in arranging
and observing the cooperative variety tests, and to farmers who
planted the tests on their farms.