Upland Cotton Variety Evaluation in Graham County, 2003
E.R. Norton and L.J. Clark
Abstract
A field trial was established during the 2003 growing season as part of the statewide
Upland Cotton Variety Testing Program. This trial was located in Thatcher with Dennis
Layton Farms as the cooperator. The location was one of eleven around the state. A
total of twelve varieties were entered from six cooperating seed companies. Varieties
included DP655BR, DP555BR, DP449BR, and DP5690R from Delta and Pine Land
Company; FM989BR, FM991R, and FM991BR from Fiber Max; ST5303R and
ST5599BR from Stoneville; Riata from CPCSD; AG3601 from Arizona Cotton Growers
Association; and SCX-7 from Salcot. The twelve varieties were planted in a randomized
complete block design with three replications. Individual plots consisted of 4, 38” rows
extending the full length of the irrigation run (1250 ft.). Plant measurements were
collected throughout the season to evaluate growth and development characteristics of
each variety. Yield and fiber quality data was collected at the end of the season by
harvesting and weighing each individual experimental unit. Sub-samples were collected
for fiber quality analysis. Percent emergence data indicated differences in seedling vigor
and stand establishment. Percent emergence ranged from a high of nearly 90% (Fiber
Max FM989BR) to less than 50% (Delta and Pine DP555BR). Even with the low percent
emergence for DP555BR an adequate stand was achieved for each variety and did not
significantly impact final yield. Significant differences were observed in final lint yields
with Fiber Max FM991BR producing the highest yield at 1690 lbs. lint per acre and
Fiber Max FM989BR producing the lowest yield at 1292 lbs. lint per acre, a difference of
approximately 400 lbs. Delta and Pine DP655BR has been the standard variety planted
in the valley for several years. The only variety producing more lint than DP655BR was
FM991BR. Lint value calculated using premium/discounts for fiber quality resulted in
FM991BR with the highest value at $952/acre. All varieties had overall premiums except
for AG3601which was discounted due to high fiber micronaire. Results from this
evaluation indicate that FM991BR appears to be an additional variety from which
growers have to choose that has the potential to perform very well in the Upper Gila
River valley.
Introduction
Variety selection is one of the most important decisions that a producer can make that will directly affect
the outcome of the year’s crop. With the development of transgenic technologies, the overall number of
varieties available has dramatically increased over the recent years making the decision of which variety to
plant more difficult.
There are several sources available to help the producer determine which variety best suits a particular farm
including seed company variety trials conducted around the state. In an effort to contribute in an unbiased
manner the University of Arizona conducts a statewide Upland Cotton variety testing program that involves
locations around the state to which seed companies may submit varieties for evaluation.
Most tests are located on grower-cooperator fields under normal production practices for that region.
These regional tests are conducted by individual county extension agents with cooperators selected from
local growers.
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104
Materials and Methods
Twelve varieties were selected by the cooperating seed companies in 2003 and planted in a randomized
complete block design with four replications. Plots were four - 38” rows wide and extended the full length
of the irrigation run of 1250 feet. Plots were planted on 28 April 2003 with 638 heat units (86o/55oF
thresholds) accumulated since January 1. Table 1 provides agronomic information for this study. Stand
counts were collected on two separate dates shortly after emergence to evaluate percent emergence and
seedling vigor of each variety. Plant measurements were taken on approximately fourteen-day intervals
throughout the growing season including plant height, number of mainstem nodes, number of aborted or
missing sites, and the number of nodes above the top, first position fresh bloom. Yield estimates were
made by harvesting the entire four-row plot, for each replication, at the end of the season and weighing
each plot with a boll buggy equipped with load cells. Sub-samples were taken from each plot for fiber
quality and percent lint estimates. Premiums or discounts were calculated based upon fiber quality for each
variety from data developed for the CCC loan schedule. The overall value of the crop was also determined
by multiplying lint yield by the adjusted price determined from fiber quality discounts or premiums.
Results
Stand count information collected shortly after emergence reveals significant differences among varieties.
Percent emergence estimates were made on 16 May and 3 June. Values from a low of near 50% to just
below 90%. Table 2 contain analysis of variance data for the percent emergence data. Some variation was
also experienced among the sample dates. Figure 1 shows seedlings/acre for each variety on the two
separate sampling dates. Some varieties experienced sharp declines in plant population in the 18 day
interval between evaluations. DP449BR and Salcot SC-7 both experienced over a 10% decrease in plant
population between sample dates (Figure 2). Planting conditions for this trial were optimum with
minimum soil temperatures never dropping below 60oF during the fourteen day period following planting.
Height to node ratio (HNR) provides a measurement of crop vigor and is calculated by dividing the total
plant height (inches) by the number of mainstem nodes. The values of HNR are plotted against normal
baselines for each of the twelve varieties in Figure 3. HNR trends consistently trended along normal
baselines throughout the season.
Fruit retention measurements provide an indication of fruit load and yield potential of a particular variety.
FR levels for each of the twelve varieties are plotted against normal baselines in Figure 4. All twelve
varieties performed in a similar manner with respect to fruit load. All varieties tracked at or above the
center (normal) baseline throughout the season. End of season FR levels were still considerably higher
than 50% indicating good yield potential for all twelve varieties.
The number of nodes above the top, first position fresh flower (NAWF) is a good indicator of progression
of a particular variety towards physiological maturity or ‘cut-out’. Levels of NAWF for each of the twelve
varieties are plotted in Figure 5 against normal baselines. Levels were consistently below normal
throughout the entire season. However, this situation is not uncommon when the fruit load is consistently
high as was experienced by this crop (Figure 4).
Final lint yields ranged from a low of 1292 lbs/acre to the highest lint yield at 1690 lbs/acre, a difference of
nearly 400 lbs/acre. Lint yield data is presented in Table 3 and Figure 6. A new variety to Graham County
performed very well in 2003, Fiber Max FM991BR. Fiber Max variety FM989BR which has performed
very well this region in past years did not perform as well in 2003. This was in part due to the presence of
unopened bolls toward the top of the plant. Another variety that performed extremely well in 2002 that did
not do as well in 2003 is Deltapine DP555BR. Deltapine DP655BR has been a standard variety planted in
this region for many years. Year in and year out DP655BR consistently performs well. To evaluate each
of the varieties with respect to the DP655BR standard a percent relative yield based on DP655BR was
Arizona Cotton Report (P-138) May 2004
105
calculated. A graph showing percent relative yield and percent relative value are shown in Figures 7 and 8
respectively. Only FM991BR performed at a level higher than the DP655BR standard with respect to lint
yield and value.
A premium or discount was calculated for each of the twelve varieties based on fiber quality results (Table
3) from high volume instrument (HVI) analysis. This premium/discount value is shown in Table 3 and
Figure 9. Fiber Max FM991BR and Deltapine DP449BR received the highest premium of over 400 points.
The only variety receiving a discount based on fiber quality was Arizona Cotton Growers Association
AG3601. Figures 10-12 show each of the fiber quality parameters and the discount/premium levels
associated with each parameter.
Results from this test demonstrate the range of quality varieties from which to choose for growers in the
Upper Gila River Valley. It is important to remember that performance in one year is not necessarily an
indication of how that variety will perform in other years. It is always a good idea to experiment with an
unfamiliar variety in small acreages at first in an effort to become familiar with it prior to planting a large
number of acres to a new variety.
Arizona Cotton Report (P-138) May 2004
106
Table 1. Agronomic information for the Graham County Upland Cotton Variety Test, 2003.
Planting Date
28 April
Final Irrigation Date
26 September
Harvest Date
30 October
Total Number of Irrigation
7
Total N Applied
83 lbs. N
General Soil Texture
Grabe Clay loam
Table 2. Percent emergence data for each of the twelve varieties on two separate sample dates for the
Graham County Upland variety trial, 2003.
Percent Emergence
Variety
16 May
3 June
FM989BR
88.3 a1
81.2 a1
DP449BR
81.7 ab
68.6 bcd
Riata
75.0 abc
73.8 ab
ST5599BR
70.1 bcd
73.4 abc
Salcot SCX-7
69.1 bcd
51.6 ef
DP655BR
68.0 bcd
73.0 abc
DP5690R
68.0 bcd
61.0 de
FM991BR
66.9 cd
62.0 cde
ST5303R
60.3 de
61.9 cde
AG3601
60.3 de
59.7 de
FM991R
59.8 de
57.1 def
DP555BR
47.3 e
48.1 f
LSD2
14.0
11.6
OSL3
0.0002
0.0001
C.V.4(%)
14.4
12.5
1
Means followed by the same letter are not significantly different according to a Fisher’s LSD means separation test.
LSD: Least Significant Difference.
3
OSL: Observed Significance Level.
4
CV: Coefficient of Variation.
2
Arizona Cotton Report (P-138) May 2004
107
Table 3. Lint yield and fiber quality characteristics for each of the nine varieties planted in 2003.
Company
FiberMax
Stoneville
Delta and Pine
FiberMax
Delta and Pine
Delta and Pine
Salcot
Delta and Pine
ACGA
Stoneville
CPCSD
FiberMax
LSD0.052
OSL3
CV (%)4
Variety
FM991BR
ST5303R
DP655BR
FM991R
DP5690R
DP555BR
SCX-7
DP449BR
AG3601
ST5599BR
Riata
FM989BR
Lint Yield
(lbs/Acre)
1690 a1
1661 a
1661 ab
1632 abc
1618 abc
1593 abc
1517 bcd
1496 cde
1398 def
1395 def
1363 ef
1292 f
144
0.0001
6.0
Percent Lint
36.0 a
35.8 a
35.0 a
34.1 a
35.5 a
36.0 a
33.9 a
34.8 a
32.3 a
34.8 a
35.5 a
32.3 a
NS
0.1218
5.0
Micronaire
4.3 a
4.4 a
4.4 a
4.5 a
4.7 a
4.4 a
4.4 a
4.3 a
5.1 a
4.3 a
4.7 a
4.3 a
NS
0.0797
5.4
Fiber
Length
(100ths)
1.10 a
1.04 a
1.07 a
1.05 a
1.07 a
1.06 a
1.08 a
1.10 a
1.08 a
1.07 a
1.08 a
1.08 a
NS
0.1035
2.5
Fiber Quality
Staple
Fiber
Length
Strength
(32nds)
(g/tex)
35.2 a
32.6 a
33.5 a
30.3 a
34.5 a
30.5 a
33.5 a
28.8 a
34.5 a
30.9 a
34.2 a
30.1 a
34.5 a
31.0 a
35.2 a
31.7 a
34.5 a
32.0 a
33.5 a
30.8 a
34.5 a
31.8 a
34.7 a
31.9 a
NS
NS
0.2394
0.1690
2.7
5.2
Uniformity
Index
81.2 ab
80.0 abc
80.5 abc
79.0 c
81.2 ab
79.7 bc
80.0 abc
81.5 ab
81.0 ab
80.2 abc
81.7 a
81.5 ab
1.8
0.0488
1.4
Premium/
Discount5
(points)
430
81
334
85
281
231
360
423
-13
280
354
380
1
Means followed by the same letter are not significantly different according to a Fisher’s LSD means separation test.
LSD: Least Significant Difference.
3
OSL: Observed Significance Level.
4
CV: Coefficient of Variation.
5
Average premium or discount applied to the lint based on CCC loan schedule.
6
Value of lint per acre based on CCC loan schedule of discounts and premiums and assuming a base value of 52.00 cents per pound.
2
Arizona Cotton Report (P-138) May 2004
108
Value6
($/acre)
952
877
920
864
886
863
844
841
725
766
757
721
120000
16 May
3 June
S eedlings Per Acre
110000
100000
90000
80000
70000
60000
601 9B R 5B R 90R 5B R 8B R 1B R 91R R IATA L COT5303R599B R
AG3 DP 44 D P 55 DP 56 DP 65 F M89 F M99 F M9
S A S T S T5
Figure 1. Number of seedling per acre on two separate sample dates counted for each of the twelve
varieties entered into the Graham County Upland Variety Test, 2003.
100
Es timated P ercent Emergence
16 May
3 June
90
80
70
60
50
40
601 9B R 5B R 90R 5B R 8B R 1B R 91R R IATA L COT 5303R599B R
AG3 D P 44 D P 55 D P 56 DP 65 F M89 F M99 F M9
S A S T S T5
Figure 2. Estimated percent emergence on two sample dates for each of the twelve varieties entered into
the Graham County Upland Variety Test, 2003.
Arizona Cotton Report (P-138) May 2004
109
2.5
Height (in.)/Node Ratio
2.0
1.5
AG 3601
DP449BR
DP555BR
DP5690R
DP655BR
FM989BR
FM991BR
FM991R
RIATA
SCX_7
ST5303R
ST5599BR
1.0
0.5
0.0
500
1000
1500
2000
2500
3000
3500
Heat Units Accumulated After P lanting
Figure 3. Height (in.) to node ratio trends for each of the 12 varieties planted in the Graham County
Upland Variety Test, 2003.
120
P ercent Fruit Retention
100
80
AG 3601
DP449BR
DP555BR
DP5690R
DP655BR
FM989BR
FM991BR
FM991R
RIATA
SCX_7
ST5303R
ST5599BR
60
40
20
0
500
1000
1500
2000
2500
3000
3500
Heat Units Accumulated After P lanting
Figure 4. Fruit retention levels for each of the 12 varieties planted in the Graham County Upland Cotton
Variety Test, 2003.
Arizona Cotton Report (P-138) May 2004
110
Nodes Above Top 1s t P os ition Fres h B loom
16
14
12
10
AG 3601
DP449BR
DP555BR
DP5690R
DP655BR
FM989BR
FM991BR
FM991R
RIATA
SCX_7
ST5303R
ST5599BR
8
6
4
2
0
500
1000
1500
2000
2500
3000
3500
Heat Units Accumulated After P lanting
Figure 5. Number of nodes above top, first position fresh bloom for each of the 12 varieties planted in the
Graham County Upland Cotton Variety Test, 2003.
1800
950
1600
1500
1400
1300
900
850
800
Value ($/acre)
Lint Yield (lbs./acre)
1700
1000
1200
1100
1000
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B S C X P449BAG 3605599B RIATM 989B
D
F
F M 9 S T D P6 F M DP DP5
ST
750
700
Figure 6. Lint yield estimates and crop value for each of the twelve varieties entered into the Graham
County Upland Variety Test, 2003.
Arizona Cotton Report (P-138) May 2004
111
Percent Relative Yield (DP655BR)
105
100
95
90
85
80
75
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B SC X P449BAG 3605599B RIATM989B
D
F M9 S T DP6 F M D P D P5
F
ST
Figure 7. Percent relative yield (relative to DP655BR) for each of the twelve varieties entered into the
Graham County Upland Variety Test, 2003.
Percent Relative Value (DP655BR)
105
100
95
90
85
80
75
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B SC X P449BAG 3605599B R IATM989B
D
F M9 S T DP6 F M DP DP5
F
ST
Figure 8. Percent relative value (relative to DP655BR) for each of the twelve varieties entered into the
Graham County Upland Variety Test, 2003.
Arizona Cotton Report (P-138) May 2004
112
Premium/Discount (points)
500
400
300
200
100
0
-100
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B SC X P449BAG 3605599B RIATM989B
D
F M9 ST D P6 F M D P D P5
F
ST
Figure 9. Premium/discount for each of the twelve varieties entered into the Graham County Upland
Variety Test, 2003 calculated based upon fiber quality data.
5.2
5.1
Discount Range
5.0
Fiber Micronaire
4.9
4.8
4.7
4.6
4.5
4.4
4.3
4.2
4.1
4.0
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B SC X P449BAG 3605599B RIATM 989B
D
F M 9 S T D P6 F M D P D P5
F
ST
Figure 10. Fiber micronaire values for each of the twelve varieties entered into the Graham County Upland
Variety Test, 2003.
Arizona Cotton Report (P-138) May 2004
113
36.0
Staple (32nds of an inch)
35.5
Premium Range
35.0
34.5
34.0
Discount Range
33.5
33.0
32.5
32.0
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B SC X P449BAG 3605599B RIATM989B
D
F M 9 ST D P6 F M D P D P5
F
ST
Figure 11. Staple length values for each of the twelve varieties entered into the Graham County Upland
Variety Test, 2003.
33.0
32.5
Premium Range
Fiber Strength (g/tex)
32.0
31.5
31.0
30.5
30.0
29.5
29.0
28.5
28.0
1
A
R
R
R
R
R
R
R
R
R
-7
91B 5303 55B 991 5690 55B SC X P449BAG 3605599B RIATM 989B
D
F M 9 ST D P6 F M D P D P5
F
ST
Figure 12. Fiber strength values for each of the twelve varieties entered into the Graham County Upland
Variety Test, 2003.
Arizona Cotton Report (P-138) May 2004
114