. . .. ... ..... ......
........... .................
.......... .
.. ........
-- ~ ~ ~ ""'. 19 9 1.
'~ [:: ' ' P0 T 0 N.~~.
H erbicide R sistance De onstrated b Cocklebur
in Cotton
Reports of common cocklebur in
cotton fields developing resistance to
the arsenical herbicides MSMA and
DSMA have become increasingly
common in the Southeast during the
past few years. These reports were
investigated through AAES research
in a greenhouse study during 1990.
Cocklebur seed from cotton fields
located near Orrville and Polk in west
Alabama were planted in 1-quart
cups of potting soil. Cocklebur plants
were treated separately at 2-leaf and
6-leaf growth stages with MSMA at
rates of 0.5 to 4.0 pound active
ingredient (adi.) per acre in a spray
volume of 15 gallons per acre.
Cocklebur obtained from Orrville
and treated at the 2-leaf stage could
not be controlled with MSMA at
Common 4
0.5 to 1.0 pound ai. per Herbicide
acre, as shown in the al/acre
table. Only 59 percent
control was obtained Control.
with the 2-pound rate. MSMA, 
0.5
Cocklebur 
from Polk 
MSMA, 2.0
treated at the 6-leaf MSMA, 4.0
stage also could not be
controlled with MSMA rates of 0.5 to
1.0 pound adi. per acre and only 48
percent control was obtained with
2 pounds adi. per acre.
Regrowth occurred on the lower
stem nodes after top growth was
burned down with MSMA rates of 2
and 4 pounds a.i. per acre. This
regrowth would allow cocklebur to
escape early herbicide treatment and
compete with cotton if no further
treatments were applied.
Cocklebur Control from Over-the-top Herbicide
Treatments
Orrville Polk
2-leaf 6-leaf 2-leaf 6-leaf
Pct Pct. Pct Pct
....... 0 0 0 0
lb .....10 60 61 4
lb .....14 65 77 4
lb .....59 72 80 48
lb .....80 75 79 68
This indicates that common cockle-
bur is developing resistance to
MSMA. Because DSMA has a com-
parable chemical makeup, similar
control response and resistance de-
velopment would be expected for
this chemical. These findings suggest
that alternative control methods for
MSMA- and DSMA-resistant cockle-
bur must be studied.
M.G. Patterson and T.V. Hicks
April 15 Planting, Best at Fairhope
Cotton is again being grown in
Alabama's coastal counties with
acreage increasing in Baldwin and
Mobile counties during the past 3
years. Because information concern-
ing the optimum planting dates for
cotton in this area is limited, an AAES
field study was initiated in 1988 to
lear more about ideal plantingdates.
The study was conducted at the
Gulf Coast Substation, Fairhope, to
evaluate the yield potential of cotton
planted April 15, May15, and June15.
Cotton was grown both with and
without Pix? plant growth regula-
tor. Yields were obtained each year
for all planting dates except the May
15 date in 1988 when dry weather
prevented the establishment of a
workable stand. , coninued 
on 
page 
2
LABAMA .0:AE R MET SAIO ?B . .riVR 
.T ?
LOWELL T. FROBISH, DIRECTOR A uB,.URthf UNIVERS.ITcor ALABAMA
~ Y-~Y~ Cl~m~-H~ -i .~~ --~
I I
April 15 Planting, continued
The highest yields were obtained
each year from the April 15 planting
date, as shown in the table.
Yields from cotton planted in
April were significantly Cotton Date of Planting-Pix 
Study, Gulf Coast
April wereSubstation, 
Fairhope
higher than yields from
other planting dates 
in 1988 Planting 
date, Seed 
cotton yield
and 1989. Yields were ap- Pix treatment 
1988 1989 1990
proximately equal for April 
Lb. Lb. Lb.
and May planting dates in April 15
1990. Pix provided a yield No Pix.......1,906 3,527 
2,384
increase for the June planting 
Maix ................... 1,730 
3,216 2,517
in 1988, but gave no 
benefits No Pix 
........ 
2,408 2,202
at other planting dates or in Pix ..................... - 2,439 2,302
other years. 
June 15
No Pix ........... 998 2,122 2,009
M.G. Patterson, M.D. 
Pegues, Pix................ 
1,256 2,070 
1,852
N.R. McDaniel, 
and E.L CardenI__..........12 
2,7 
,8
Cotton Shows Little Response to Deep Placement
of Potassium Fertilizer
No-till Cotton Matches
Yield of Conventional
Cotton
Conservation tillage planting sys-
tems for cotton have been studied
since the early 1980's in Alabama, but
on-farm use of conservation tillage
has been only on a limited scale.
However, new conservation compli-
ance regulations and a renewed in-
terest in reducing labor, machinery,
and fuel costs associated with con-
continued on page 3
Research in Mississippi has shown
that deep placement of a narrow
band of potassium fertilizer under
the cotton row can produce increases
in lint yields. AAES field studies
were initiated in 1989-90 to see if
similar results could be obtained in
Alabama.
The studies were conducted at the
E.V. Smith Research Center, Shorter,
and the Tennessee Valley Substation,
Belle Mina, in 1989, and at the
Prattville Experiment Field, Pratt-
ville, in 1990.
Several treatments were compared
at each research site. Deep place-
ment treatments at the sites were
achieved using a dry fertilizer appli-
cator that applies fertilizer at depths
of 6 to 15 inches behind a subsoil
shank. Potassium was applied deep
at rates ranging from 0 to 90 pounds
K20 per acre. Other treatments re-
ceived K applied as surface broadcast
applications at rates ranging from 0
to 90 pounds K20 per acre with and
without subsoiling. Two additional
deep placement treatments received
1,500 pounds limestone per acre and
1,500 pounds limestone plus 90
pounds K20 per acre. A final treat-
ment of 120 pounds K,20 per acre
deep placed was included at the Ten-
nessee Valley Substation and Pratt-
ville Experiment Field.
At the E.V. Smith Research Center
and the Tennessee
Valley Substation,
no consistent yield
responses were
observed for the
deep placement
treatments. A
yield response to
the deep place-
ment of K was
obtained in 1990
at the Prattville Ex-
periment Field, as
shown in the table,
but a greater yield
response was ob-
tained by apply-
ing the same rates
of K as a surface
broadcast applica-
tion.
Initial results
from this series of
field studies sug-
gest that, for cotton, the deep place-
ment of K fertilizer on the soils stud-
ied was not superior to surface
broadcast applications of K fertilizer.
G.L Mullins, C.H. Burmester,
and D.W. Reeves
2
Cotton Yield Response to Deep Placement of K,
Prattille Experiment Field, 1990
Treatment
Application rate/acre, lb. 
Seed cotton,
per acre
K
2
O 
Limestone
1  
Subsoiled
Lb.
Surface applied
2
30 0 No 2,573
60 0 No 2,707
90 0 No 2,423
30 0 Yes 2,583
60 0 Yes 2,700
90 0 Yes 2,867
Deep placement
30 0 Yes 2,364
60 0 Yes 2,596
90 0 Yes 2,691
30 1,500 Yes 2,589
90 1,500 Yes 2,550
120 0 Yes 2,534
No K
2
0 or lime - No 2,439
No K
2
0 or lime - Yes 2,374
'Limestone application in selected treatments refers to the deep
placement of lime with a dry fertilizer applicator.
2
Potassium fertilizer broadcast on soil surface (after subsoiling)
prior to secondary tillage.
3
Dry K fertilizer placed in a vertical band from 6 to 15 inches, applied
approximately 3 weeks prior to planting.
No-till Cotton, continued
ventional cotton pro- Seed Cotton
duction has increased Ter
interest in no-till or Tillage
minimum tillage cotton. type
Vetch, crimson clo-
ver, rye, wheat, and
No-till
old crop stubble 
have Into cotton 
s
been evaluated as co- Into wheat c
ver crops for no-till 
Conventional
cotton in AAES experi-
ments. Use of in-row subsoiling has
also been evaluated. Earlier studies
found that vetch and dover covers
created cotton establishment prob-
lems because the vetch and clovers
were difficult to kill and the thick
mulches kept the soil cool, increasing
seedling diseases and insect problems.
In-row subsoiling was found to be
beneficial only on sandy soils
which often develop "hard pans" or
"traffic pans." Subsoiling of clayey
soils at planting often resulted in
poor stands when wet clay that was
pulled to the soil surface impeded
planting.
Research during the last 3 years
has concentrated on growing cotton
no-till into small grains or old cover
crops. A rotation experiment at the
Tennessee Valley Substation, Belle
Mina, in 1988 was modified to in-
i Yields of No-till and Conventional Till Cotton,
nnessee Valley Substation, Belle Mina
Seed cotton yield/acre
1988 1989 1990 Av.
Lb. Lb. Lb. Lb.
3tubble ....... 1,140 2,440 1,510 1,697
,over .......... 1,380 2,490 1,840 1,903
.................. 1,400 2,780 1,700 1,960
clude planting cotton no-till into old
cotton stubble or a wheat cover crop.
The wheat cover crop and winter
weeds in the old stubble were killed
2 weeks prior to planting. The no-
till cotton was planted into the
stubble with a conventional planter
modified with a coulter directly in
front of each row to reduce trash.
Good cotton stand establishment
was found with both no-till systems;
however, seed cotton yields during
the last 3 years were increased by
200 pounds per acre by planting
into wheat cover compared to old
cotton stubble. The greatest differ-
ences were found in the dry years of
1988 and 1990. Conventionally
planted cotton and cotton planted
no-till into wheat cover have pro-
duced similar yields.
C.H Burmester
Specialized Cultivator
Tested for Minimum
Tillage Cotton
A series of minimum tillage cotton
experiments at the Tennessee Valley
Substation, Belle Mina, and the
Wiregrass Substation, Headland,
during a 4-year period revealed that
weeds could be effectively controlled
using broadcast herbicide applica-
tions. However, this increases weed
control costs above conventional till-
age systems where herbicides are
banded over the row and the middles
are cultivated. AAES experiments
were initiated to evaluate the poten-
tial of reducing weed control costs
by using a specialized cultivator in
minimum tillage cotton.
Cotton was planted into desiccated
rye cover using a strip tillage planter
(Ro-Till?). A preemergence herbi-
cide mixture (Cotoran? plus
Zorial?) was either banded over the
row or broadcast. Additional weed
control inputs included minimum till-
age cultivation and postemergence
directed sprays. A conventional till-
continued on page 4
Broiler Litter Evaluated for Use as Cotton Fertilizer
Alabama's growing poultry in-
dustry and increased environmental
concerns with excessive application
of broiler litter to small acreages have
created an interest in the use of broiler
litter on row crops. With more than
200,000 acres of cotton in northern
Alabama in close proximity to the
broiler industry, cotton could provide
an important outlet for litter disposal.
However, little research on cotton's
response to broiler litter applications
has been available and possible prob-
lems associated with broiler litter ap-
plications, such as rank vegetative
growth and delayed cotton maturity,
have not been addressed.
Effects
Three AAES
field studies Treatment/acre
were conducted
in 1990 at 
the No N 
.....................
Tennessee Val- 
60 lb. N.............
ley Substation, 120 b. N...............
Belle Mina, and Litter, 
2 tons.
in farmers' fields Litter, 4 tons ..........
in Cullman and
Lauderdale counties to evaluate the
effects of broiler litter on cotton
growth and development. In these
studies, broiler litter rates of 2, 3, and
4 tons per acre were compared to 0,
60, and 120 pounds fertilizer nitro-
gen (N) per acre. All litter applica-
tions were incorporated before plant-
of Broiler ULitter on Cotton Yields
Seed cotton yields/acre
Tennessee Valley Cullman Lauderdale
Lb. Lb. Lb.
1,840 910 850
2,230 1,210 1,160
2,450 1,330 1,280
2,460 1,250 1,100
2,560 1,200 1,220
2,520 1,320 1,280
ing and N fertilizers were applied half
at preplant and half as sidedressing.
No detrimental effects on cotton
growth and no additional weed
pressures were found when litter was
used. Early season height and node
measurements indicated that litter-
continued on page 4
3
Broiler Litter, continued
treated cotton was growing slightly
faster than cotton treated with com-
mercial N fertilizer. At all sites, the
2-ton-per-acre broiler litter treatment
produced seed cotton yields equal to
the standard N fertilizer treatment
(60 pounds N per acre). However,
extremely hot, dry weather from
mid-July until September equalized
most treatment effects and possible
problems with late season N release
from the broiler litter could not be
evaluated.
These results indicate that broiler
litter has potential as a fertilizer for
cotton.
C.H. Burmester, C.W. Wood,
and C.C. Mitchell, Jr.
Research Seeking
Ways to Make Cotton
Nonflammable
The comfort and durability of cot-
ton fabric make it a natural choice for
use in sleepwear, but economic and
safety factors have kept it out of the
children's sleepwear market for
more than 15 years. AAES research is
working to reopen this market to
cotton.
Problems arose with cotton when
federal law began to require child-
ren's sleepwear to be flame resistant.
Cotton's natural flammability re-
quires the addition of expensive
flame-retardant finishes to ensure
nonflammability. Unfortunately,
interactions between metal ions
found in hard water and compounds
in phosphate-free detergents can di-
lute the effectiveness of flame retar-
dants on cotton.
Research has shown that this dilu-
tion effect is caused by an extremely
complicated chemical reaction.
Rather than unravel this process,
many sleepwear manufacturers
have replaced cotton with fabrics
that can be managed more easily
Specialized Cultivator, continued
age treatment using standard weed
control techniques was included for
comparison.
Weed control in minimum tillage
plots which received banded
preemergence herbicide applications
followed by cultivation alone or culti-
vation plus postemergence directed
sprays was equal to conventional
tillage weed control in 1989, as shown
in the table. Cotton yields for both
minimum and conventional tillage
systems also were equal that year.
However, poor annual grass control
and less expensively. Studies at the
Alabama Agricultural Experiment
Station have continued to explore
this intricate chemical process in an
effort to overcome the problems as-
sociated with making cotton flame
retardant.
Flame-retardant treatments cause
cotton fabric to char rather than burnm
by encouraging the formation of wa-
ter and inhibiting the rapid break-
down of ignited material. Cotton fi-
bers are composed almost entirely
of cellulose, long-chain molecules
which are the basis for most plants.
The Auburn research has concen-
4
in minimum tillage plots where
preemergence herbicides were
banded and followed by cultivation
alone resulted in total yield loss for
this treatment in 1990. Annual grasses
were not inverted by the minimum
tillage cultivator and rerooted after
rainfall. Minimum tillage plots which
received broadcast preemergence
herbicide applications either alone or
followed by cultivation, or cultivation
plus postemergence directed sprays
produced good cotton yields and ex-
cellent weed control both years.
M.G. Patterson, B.E. Norris,
H.E. Burgess, and W.B. Webster
trated on finding out how metal ions
influence the burning (thermal
breakdown) of cellulose.
In the experimental work, cotton
fabric was thoroughly cleaned, and
sodium, potassium, magnesium, and
calcium salts of chlorine and carbon-
ate were applied to or formed in the
fabric. These samples were then
burned at various rates and tem-
peratures. When the burning was
complete, the resulting products
were separated and identified.
It was discovered that all the inor-
ganic salt additives increased the
continued on page 5
Effectiveness of Cultivation in Minimum-tillage Cotton at Tennessee Valley Substation,
Belle Mina
Weed control Cotton yield/acre
Treatment
1  
Grass Broadleaf
1989 
1990 
1989 
1990
Pct. Pct. Pct. Pct. Lb. Lb.
Strip-tillage
Banded,
cultivated ........................ 83 45 81 78 2,485 0
Banded,
cultivated, PDS.............. 88 68 89 83 2,845 1,788
Broadcast ....................... 94 97 94 96 2,491 1,992
Broadcast,
cultivated........................ 
95 97 95 
98 2,365 
2,025
Broadcast,
cultivated, PDS.............. 95 98 95 98 2,807 1,948
Conventional tillage
Banded,
cultivated, PDS............... 75 89 79 89 2,644 2,284
'Herbicide banded or broadcast; cultivated= cultivation twice during the growing season;
PDS = postemergence directed spray.
I 
I
HOld Rotation" Helps Identify Least Risky Rotations
Economic analysis of data from 92
years of the Alabama Agricultural
Experiment Station's "Old Rotation"
experiment is providing information
about the least risky rotation alterna-
tives for cotton production.
In the AAES economic study, data
from the Old Rotation were used to
analyze the effect of alternative
rotations for sustainable cotton
yields. In particular, the analysis
looked at the effect of winter le-
gumes following cotton as a source
of green manure and nitrogen for
crops involved in the rotations. Ro-
tations included in the long-running
study were: (1) continuous cotton,
with and without winter legumes
and nitrogen fertilizer; (2) 2-year ro-
tations of cotton, winter legumes,
and corn, with and without nitrogen
fertilizer; and (3) 3-year rotations of
cotton, winter legumes, corn, and
small grains-soybeans double-
cropped, with nitrogen fertilizer ap-
plied to the small grains.
All rotations received 80 pounds of
phosphorus (P
2
0O) and 60 pounds of
potassium (K20) per acre per year
applied to the summer crop or winter
legume, or split between the summer
crop and winter legume.
The net return potential of each of
these alternative rotations was calcu-
Nonflammable Cotton, continued
amount of carbon dioxide, water, and
carbon monoxide released by the fab-
ric. The yields of these products in-
creased or decreased as additional
salts were added, depending on the
type of salt used.
These results are the first steps in
explainingthe complicated chemistry
involved when cotton burns. Once
this process is understood, new flame
retardant finishes could be developed
for cotton fabrics which will reopen
the children's sleepwear market to
cotton and allow consumers a wider
choice of fabrics.
I.R. Hardin
lated using the past 10 years' data.
Comparisons were also made of the
economic riskiness of the alternative
rotations on 570 acres of cropland.
The greatest net returns were real-
ized from the continuous cotton with
winter legumes and the 3-year rota-
tion of cotton-winter legumes-small
grains-soybeans. In contrast, the con-
tinuous cotton without winter le-
gumes and without nitrogen fertil-
izer and the 2-year rotation of cot-
ton-winter legumes-corn (without
nitrogen fertilizer) did not generate
enough income to cover out-of-pocket
(variable) costs.
Results of the risk analysis indicate
that the most profitable farm plan
included the 3-year rotation of cotton,
winter legumes, corn, and small
grains-soybeans (1/3 of the acreage
to cotton, 1/3 to winter legumes-corn,
1/3 to rye-soybeans double-
cropped). This 3-year rotation also
had a high economic risk which
might be reduced by including the
rotation of continuous cotton with
winter legumes in the farm plan.
This shift, however, results in a re-
duction of potential net return.
Despite a slightly decreased net
return, the best overall management
strategy to minimize risk while
achieving an expected return of
$52,581 involved planting 31 percent
of the cotton acreage in continuous
cotton with winter legumes and the
remainder to the 3-year rotation of
cotton-winter legumes-corn-small
grains-soybeans.
J.L Novak, C.C. Mitchell, Jr., and
J.R. Crews
Reniform Nematode on Cotton in Alabama
Cotton producers across the State
have reported a general decline in
cotton production in many of their
fields. In a few cases, yields have
declined to less than 50 percent of
their original production capacity.
Reniform nematode has now been
identified as being at least partially
responsible for that decline in pro-
duction.
Reniform nematodes 
attack cot-
ton in all stages of development.
Cotton fields infested with reniform
nematode do not display the typical
signs associated with other plant
parasitic nematodes. Damage is
general and spread throughout the
entire field rather than being re-
stricted to plants in localized areas
within the field. Reniform-infested
cotton plants are usually stunted but
exhibit no other unusual above-
ground symptoms. Affected cotton
roots exhibit poor growth but form
no galls or lesions like those caused
by root-knot nematodes.
Cotton soil samples analyzed at
the Plant Diagnostic Laboratory in
Auburn and a Statewide systematic
survey initiated last summer have
indicated that this nematode is
present in all major cotton produc-
ing areas of Alabama. It is also found
in almost all soil types, which makes
practically all Alabama cotton fields
potential targets for infestation.
Nematicide and crop rotation stud-
ies conducted through the Alabama
Agricultural Experiment Station and
in other Southeastern States indicate
that reniform can be controlled by
either rotation, nematicides, or a
combination of both. Data from
nematicide trials revealed that
Telone? and Temik? increased
cotton yields by as much as 75 per-
cent in heavily infested fields.
W.S. Gazaway
5
Cotton Varieties Tested
at Gulf Coast Produce
Good Yields
For years virtually no cotton was
grown in extreme southwest Ala-
bama (Baldwin and Mobile counties).
In response to increased interest in
planting cotton by farmers in this
area, an abbreviated variety test was
conducted in 1987 at the Gulf Coast
Yields of Three Top Producing Varieties,
Gulf Coast Substation, Fairhope
Variety Lint yield/acre
Lb.
Deltapine 90 ............... 1,050
DES 119 ..................... 1,040
HS46 ...................... 1,031
Substation, Fairhope, on eight cotton
varieties. The test was expanded the
following year to a regular cotton
variety test with 30 varieties.
Cotton yields from the trials have
been excellent, averaging about 1.5
times the State cotton yield average in
Alabama. The average yield for all
varieties was 752, 695, 994, and 946
pounds per acre in 1987, 1988, 1989,
and 1990, respectively. Varieties
with the highest 3-year average
lint yields per acre were Deltapine
90, DES 119, and HS46. Yield aver-
ages for these varieties are shown in
the table.
W.C. Johnson
EDITOR'S NOTE
Mention of company or trade names does not
indicate endorsement by the Alabama Agricul-
tural Experiment Station or Auburn University
of one brand over another. Any mention of non-
label uses or applications in excess of labeled rates
of pesticides or other chemicals does not constitute
a recommendation. Such use in researchis simply
part of the scientific investigation necessary to
fully evaluate materials and treatments.
Information contained herein is available to all
persons without regard to race, color, sex, or
national origin.
C O N T RIB U T O R S T O
C 0 T T 0 N
R E S E A R C H
Alabama Cotton Commission Rhone-Poulenc, Inc.
Chembred, Inc. StonevillePedigreed Seed 
Company
Delta and Pine Land Company Tennessee Valley Authority
Dow Elanco Terra International
HyPerfomer Seed Company USDA, ARS
Editor's Note: It is the goal of the Alabama Agricultural Experiment
Station (AAES) to distribute annual issues of its Cotton Research Update to all
persons who can use the information reported. At the same time, the AAES does
not wish to send copies to anyone who does not wish to receive the report. With
your help, we can achieve this goal. Will you please use the form below to send
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Add the following name to receive the AAES Cotton Research Update. I
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6
March 1991 3.5M ,, II