Result Demonstration/Applied Research Report

2006 Runnels County

Cotton Harvest Aid Demonstration

Cooperator: Paul Minzenmayer

Rick Minzenmayer - IPM for Runnels and Tom Green Counties

Marty Gibbs, Runnels County Extension Agent - Agriculture

Dr. Billy Warrick, Extension Agronomist (San Angelo, Texas)


    Twelve treatments were applied over the top of cotton on September 11 to prepare for harvest. The plot was established on Paul Minzenmayer’s Farm located 6 miles north of Ballinger, Texas. The chemicals were applied to Stoneville 4700 B2RF cotton that had 70 percent of its bolls open. Leaf shed was less than one percent when the plot was established. When these plots were evaluated on September 21, 2006 (10days after the treatments were applied), most of the treatments resulted in an increase in open bolls, leaf defoliation, and leaf desiccation. In this test regrowth was becoming a problem in only 10 days and may have to be desiccated or removed before harvest. Some of the materials applied are known to be better at desiccating or removing juvenile growth; these include Aim, Blizzard, ET, Ginstar, and Resource.


     In the Southern Rolling Plains, cotton is usually planted starting in mid-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:           Paul Minzenmayer

Location:                                            6 miles north of Ballinger, Texas

Crop Production Information:

            Variety Planted:                     Stoneville 4700 B2F

            Planting Pattern:                    Planted solid on 40 inch rows

            Irrigation:                               No irrigation available

            Number of Irrigations:            None

Harvest Aid Application Information: 

            Date Applied:                         September 11, 2006

            Wind Speed:                           9.0 to 10.0 miles per hour

            Wind Direction:                      North

            Air Temperature:                    79 to 860 Fahrenheit

            Relative Humidity:                   39 to 51%

            Carrier:                                   15.0 gallons of water per acre

            Pressure:                                 32 pounds per square inch

            Nozzle Size:                           11002 extended range flat fan over the top of each row and one 8002 Extended Range nozzle on each side of the row.

            Boom Height:                         36 inches

            Cotton Height:                        28 inches

            Ground Speed:                        4.0 miles per hour

            Application Device:               Self propelled rig with 13.33 foot boom

            Plot Size:                                13.33 feet X 50 feet

            Test Design:                           randomized block design replicated three times

Plant Information

     At the time of application, the upper most cotton bolls were cross-sectioned, the seed coats were dark, and the cotyledons well developed. Cotton height averaged 28 inches and 70 percent of the bolls were open. Plants had regrowth in the top and bottom portion of the plants . Leaf defoliation was less than one percent.

Results and Discussion

   The cotton at the time of application was 70 percent open with most of the remaining bolls being mature. The application of the harvest aids did impact boll opening, percent defoliation and percent desiccation. Several factors contributed to the success of the harvest aids applied, these include: 1) The cotton was mature; 2) Chemical coverage was excellent due to gallonage, pressure used, and wind; 3) Air temperatures for the 10 days after application were warm with a few cool night temperatures. Leaf defoliation was higher than the check in all treatments and the increase ranged from 6 to 11 percent on September 21, 2006 (10 days after the treatments were applied). The removal of leaves result in rapid development of the juvenile leaves and some leaves were close to half grown by September 21. The data collected on September 21 is reported in Table 1.

Table 1. Runnels County Cotton Harvest Aid Test (Paul Minzenmayer Farm, 2006)

September 21, 2006 (10 days after treatments were applied)

Harvest Aid

Chemicals Applied

(2 rows of each)

Rate Applied

Per Acre

Cost of

Harvest Aid

 Per Acre


Open Bolls





Gramoxone Inteon +
Activator 90

6.0 oz. +

9.6 oz.

$1.33 +


98.0 ab

77.0 bcd

6.3 d

Gramoxone Inteon +
Activator 90

12.0 oz. +

9.6 oz.

$2.66 +


96.0 abc

70.3 ef

23.3 bc

Gramoxone Inteon +
Activator 90

24.0 oz. +

9.6 oz.

$5.32 +


95.7 abc

75.7 cde

19.3 c

Firestorm + Activator 90

16.0 oz. + 9.6 oz.

$4.33 + $1.68

97.0 abc

77.3 bcd

20.0 c

Gramoxone Inteon + Prep +
Herbimax (C.O.C.)

5.0 oz. + 21 oz. +

19.2 oz.

$1.11 + $6.23 +

+ 1.39

98.0 ab

82.7 b

7.7 d

Def + Prep +
Activator 90

16.0 oz. + 16.0 oz. + 9.6 oz.

$6.25 + 4.75

+ 1.68

93.3 bc

80.7 bc

8.3 d




87.7 d

4.0 g

0.0 e


5.0 oz.


94.3 abc

77.7 bcd

8.3 d


7.0 oz.


93.0 c

88.7 a

6.3 d

Aim + Prep +
Herbimax (C.O.C.)

0.75 oz. + 16 oz. +

19.2 oz.

$3.17 + $4.75 + $1.39

98.0 ab

69.7 ef

26.7 b

ET + Prep +
Herbimax (C.O.C.)

1.5 oz. + 16 oz. +

19.2 oz.

$3.75 + $4.75 + $1.39

98.7 a

72.0 de

25.0 bc

Blizzard + Prep +
Herbimax (C.O.C.)

0.6 oz. + 16 oz. +

19.2 oz.

$6.00 + $4.75 + $1.39

97.0 abc

65.0 f

35.0 a

Resource + Prep +
Herbimax (C.O.C.)

8.0 oz. + 16 oz. +

19.2 oz.

$9.50 + $4.75 + $1.39

97.7 abc

71.7 de

25.0 bc


      NOTE:       In Table 1 the individual or combination of letter a, b, c, d, e, f, or g shown beside the number are to indicate statistical significance. There is no statistical difference between numbers that have the same letter (even when there appears to be a large difference in results between the materials applied). Also, to account for 100 percent of the leaves you would add the percent defoliation plus the percent dessication and subtract from 100. The difference represents the number of original green leaves still remaining on the plant.

     In this test regrowth was becoming a problem in only 10 days and may have to be desiccated or removed before harvest. Some of the materials applied are known to be better at desiccating or removing juvenile growth; these include Aim, Blizzard, ET, Ginstar, and Resource. Please note that a crop oil concentrate was used in tank mixes that contained Aim, Blizzard, ET, and Resource. For maximum performance with these products C.O.C. is an important part of the tank mix.

     Increased boll opening was noted in all plots. In the Aim, Blizzard, ET, Ginstar, and Resource plots an abscission layer between the petiole and the main stem had formed but the leaves were still loosely attached.

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. Several of the treatments were in the 6 to 10 dollar per acre range and the use 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.


I want to take this opportunity to thank Paul Minzenmayer for his help in plot establishment and management. Also a word of thanks to Pam Halfmann for her help in plot establishment.

I would also like to thank the companies that provided the chemicals for this harvest aid test. These include:

            - Bayer CropScience who provided the Def, Ginstar, and Prep

            - Chemtura who provided the Blizzard and Firestorm

            - FMC Corporation who provided the Aim

            - Nichino America who provided the ET

            - Syngenta Crop Protection, Inc. who provided the Gramoxone Inteon

- Tri-State Chemical DBA United Agra Products (UAP) who provided the

               C.O.C. (Herbimax) and N.I.S. (Activator 90)

            - Valent USA Corporation who provided the Resource

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.