Result Demonstration/Applied Research Report


2002 Glasscock, Reagan, and Upton Counties
Cotton Harvest Aid Demonstration

Cooperator: Andy Wheeler

Warren Multer, Extension Agent - IPM; Steve Sturtz, Glasscock County Extension Agent;
Robert Scott, Reagan County Extension Agent; Raymond Quigg, Upton County Extension Agent;
and Dr. Billy Warrick, Extension Agronomist (San Angelo, Texas)


Summary

Twelve treatments were applied over the top cotton on August 28 to prepare cotton for harvest. The plot was established on Andy Wheeler's Farm located 18 miles south and 1 miles west of Garden City. The chemicals were applied to cotton that had 40 percent of its bolls open. Leaf shed was less than one percent. When these plots were evaluated on September 10, 2002 (13 days after the treatments were applied) most of the treatments resulted in increased boll opening, leaf defoliation and leaf desiccation.

Objective

In the Trans-Pecos Area of Texas, cotton is usually planted starting in early May. Because of this planting date, many producers do not use harvest aids to terminate the cotton. When growing conditions are favorable, most of the cotton in this area is ready for harvest thirty days before the first killing freeze. The delay in harvest reduces the income of farmers due to the loss of lint yield and fiber quality. Even though the cost of several of the harvest aid treatments are expensive, there is usually a product that is economically justified that can be used effectively for crop termination. The intent of this field test is to: 1) determine the effectiveness of harvest aids at defoliating, desiccating, and opening bolls on cotton 2) provide producers the opportunity of observing how effectively the harvest aid materials work, and 3) determine the economic feasibility of using the harvest aid material.

Materials and Methods

Cooperating County Producer: Andy Wheeler
Location: 18 miles south and 1 miles west of Garden City

Crop Production Information:
Variety Planted: Deltapine Acala 90
Planting Pattern: Solid on 40 inch spacing
Irrigation: Drip
Number of Irrigations: Throughout the season

Harvest Aid Application Information:
Date Applied: August 28, 2002
Wind Speed: 6.0 to 10.0 miles per hour
Wind Direction: South by Southeast
Air Temperature: 83 to 940 Fahrenheit
Relative Humidity: 22 to 46%
Carrier: 10 gallons of water per acre
Pressure: 32 pounds per square inch
Nozzle Size: 11002 extended range flat fan over the top; 20 inch centers
Boom Height: 40 inches
Cotton Height: 28 to 30 inches
Ground Speed: 4.0 miles per hour
Application Device: Self propelled rig with 13.33 foot boom
Plot Size: 13.33 feet X 200 feet
Test Design: randomized strip design

Plant Information
At the time of application, the upper most cotton bolls were cross-sectioned and the seed coats were dark and the cotyledons well developed. Cotton height ranged from 28 to 30 inches. Plants showed minimum stress and leaf defoliation was less than one percent.

Results and Discussion

The percent of open bolls increased by 40 to a minimum of 70 percent in the 13 days after the treatments were applied. The leaf defoliation was 45 to 75 percent better than the check plot. Desiccation was highest in plots that had 15 to 21 ounces of Cyclone Max applied. Information collected on September 11th is reported in Table 1.

Several discussion items are seen in this plot. In the treatment of Aim at 0.5 ounce plus Finish at 8 ounces the level of leaf defoliation and desiccation was low. This plot was established to show that a Crop Oil Concentrate was needed with Aim. Aim was not used at a 1 ounce rate in any of the plots so juvenile growth desiccation was not observed.

Table 1. Reagan County Cotton Harvest Aid Test, 2002
(Note: By clicking on the underlined treatment names you can see the plot being rated.
The picture is taken in the center of a four row treatment.)

Harvest Aid
Chemicals Applied
(4 rows of each)

Rate Applied
Per Acre

Cost of
Harvest Aid
Per Acre

%
Open Bolls


%
Defoliation


%
Desiccation

Regrowth
Rating
Top, Bottom

Prep +
Def/Folex

16 oz. +
16 oz.

$6.66 +
5.88

90

75

1

Top= 1
Bottom= 0

Check

--

$0.00

70

15

0

Top= 0
Bottom=
0

Cyclone Max +
LI-700

5 oz. +
6.4 oz.

$1.48 +
$1.28

92

80

2

Top= 1
Bottom=
0

Cyclone Max +
LI-700

10 oz. +
6.4 oz.

$2.96 +
$1.28

90

70

20

Top= 1
Bottom=
0

Cyclone Max +
LI-700

15 oz. +
6.4 oz.

$4.44 +
$1.28

85

60

35

Top= 1
Bottom=
0

Aim +
Cyclone Max +
LI-700

0.5 oz. +
6 oz. +
6.4 oz.

$2.81 +
$1.78 +
$1.28

90

75

3

Top=1
Bottom=
0

Aim +
Cyclone Max +
LI-700

0.5 oz. +
10 oz. +
6.4 oz.

$2.81+
$2.96 +
$1.28

90

80

7

Top= 1
Bottom=
0

Aim +
Finish

0.5 oz. +
8 oz.

$2.81+
$5.36

80

75

0

Top= 0
Bottom=
0

Ginstar

4 oz.

$5.88

80

85

0

Top= 0
Bottom=
0

Ginstar +
Cyclone Max +
LI-700

4 oz. +
4 oz. +
6.4 oz.

$5.88 +
$1.18 +
$1.28

80

83

2

Top= 0
Bottom=
0

Ginstar

8.0 oz.

$11.75

80

90

0

Top= 0
Bottom=
0

Aim +
Cyclone Max +
LI-700

0.25 oz. +
21 oz. +
6.4 oz.

$1.41 +
$6.22 +
$1.28

85

60

39

Top= 1
Bottom=
0

Aim +
Cyclone Max +
LI-700

0.25 oz. +
10 oz. +
6.4 oz.

$1.41 +
$2.96 +
$1.28

85

85

10

Top= 1
Bottom=
0

Results and Discussion (continued)

Plots receiving Ginstar at 4 ounces alone or combined with Cyclone Max at 4 ounces had over 80 percent leaf defoliation. The Ginstar rate of 4 ounces was not high enough to cause juvenile growth to abscise or desiccate. When the rate of Ginstar was increased to 8 ounces the juvenile growth was aborted or desiccated.

Prep at 16 ounces plus Def at 16 ounces did not perform as well as expected. When compared to the check it was significantly better in boll opening and leaf defoliation. However, it performance was only considered fair to good when compared to the best treatments in this test. The Def and Prep applied by the producer to the remaining portion of the field had acceptable levels of leaf defoliation and boll opening.

Cyclone Max performed as expected. The day the treatments were applied was sunny and the 5 ounce treatment defoliated and opened bolls as well as any treatment in the test. The 10 and 15 ounce Cyclone Max treatments had levels of desiccation that ranged from 20 to 35 percent. Boll opening was high in all of the Cyclone Max plus surfactant plots.

Economic Analysis
This test can be used to document the results obtained from the use of harvest aids. If the same treatments are consistently at the top of the list for several years, then producers may want to incorporate those treatments into their cotton production program. Most of the treatments were in the 6 to 8 dollar range per acre and the use of several of these treatments should result in increased profits for producers. It is important to remember that a higher lint yield is not the only way of increasing profit from the use of a harvest aid. Other factors include: timely harvest, improved fiber quality, improved harvesting efficiency, and higher percent lint turnout at the gin.

Acknowledgments

I want to take this opportunity to thank Andy Wheeler for his help in plot establishment and management.

I would also like to thank the companies that provided the chemicals for this harvest aid test, these included:

Trade names of commercial products used in this report are included only for better understanding and clarity. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas A&M University System is implied. Readers should realize that results from one experiment do not represent conclusive evidence that the same response would occur where conditions vary.