2002 Runnels County Cotton Harvest Aid Demonstration

Result Demonstration/Applied Research Report

2002 Runnels County
Cotton Harvest Aid Demonstration

Cooperator: Allen Hohensee
Rick Minzenmayer, Extension Agent – IPM; Marty Gibbs and Tom Guthrie, Runnels County Extension Agent;
and Dr. Billy Warrick, Extension Agronomist (San Angelo, Texas)

Summary

Twelve treatments were applied over the top cotton on September 6 to prepare cotton for harvest. The plot was established on Allen Hohensee’s Farm located 4 miles west of Lowake. The chemicals were applied to cotton that had 60 percent of its bolls open. Leaf shed was less than five percent. When these plots were evaluated on September 17, 2002 (11 days after the treatments were applied) most of the treatments resulted in an increase in boll opening, leaf defoliation and leaf desiccation.

Objective

In the Concho Valley Area of Texas, 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: Allen Hohensee
Location: 4 miles west of Lowake

Crop Production Information:

Variety Planted: Deltapine 5415
Planting Pattern: Two-in-1-out on 40 inch rows
Irrigation: Dryland Production
Number of Irrigations: None

Harvest Aid Application Information:

Date Applied: September 6, 2002
Wind Speed: 2.0 to 4.0 miles per hour
Wind Direction: South by Southeast
Air Temperature: 77 to 850 Fahrenheit
Relative Humidity: 44 to 56%
Carrier: 11.5 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 no signs of stress and leaf defoliation was less than five percent.

Results and Discussion

The application of the harvest aids resulted in a slight improvement in boll opening when compared to the check. Since 60 percent of the cotton was open at the time the harvest aids were applied and remaining bolls mature, the impact to boll opening was slight. Leaf defoliation was higher than the check in all treatments and the increase ranged from 5 to 90 percent by the time of the evaluation conducted on September 17, 2002 (11 days after the treatments were applied). Leaf desiccation was high in most of the plots where Cyclone Max rates above 10 ounces were used. The information collected on September 27th is reported in Table 1.

Table 1. Runnels 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 two rows of that particular treatment.)

Results and Discussion (continued)

When these plots were evaluated on September 17, 2002 (11 days after the treatments were applied) most of the treatments applied had a significant difference in leaf defoliation and leaf desiccation. The amount of regrowth in the top and bottom portion of the plants varied between treatments, however, no regrowth was high enough to impact harvesting or ginning.

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.

Plots receiving Ginstar at 4 ounces alone or combined with Cyclone Max at 4 ounces had 45 to 87 percent more leaf defoliation than the check. 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 not significantly better in leaf defoliation. Its performance was considered poor when compared to the best treatments in this test.

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 up to 30 percent.

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 Allen Hohensee 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:

• Bayer Corporation provided the Def, Finish, Ginstar, and Prep
• FMC Corporation who provided the Aim
• Syngenta Crop Protection, Inc. who provided the Cyclone Max
• Tri-State Chemical DBA United Agra Products (UAP) who provided the LI700

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.