The cotton producer in Texas once again finds himself in the familiar situation of harvesting his crop. Some regions of the state are beginning to use harvest aids, while in other regions the cotton plant is in early development.

Old questions come up regarding when to terminate the crop and what product or combination of products should be used to maximize return on investment. That return correlates with cotton quality and weight. Cotton quality and weight are affected by either good or bad results from harvest aids. You can expect better results when applications are made in warm temperatures, sunny weather, when nitrogen levels are low in both the soil and the plant, and the soil moisture is low.

The crop's yield potential plays an important role in the decision making process as to what harvest aids are used and which ones are economical. Generally, higher yielding cotton requires a combination of products for best results.

There are many different types of harvest aids. Products such as Cyclone Max© injure the leaf and stimulate the abscission process. Products such as Ginstar© defoliate and reduce regrowth. Ethephon products, such as Prep©, cause increased ethylene production and stimulates boll opening. Desiccants, such as Boa©, kill plant tissue and cause rapid loss of water from the foliage.

Good spray coverage is essential as harvest aids are not readily translocated within the plant. Each leaf that is to be removed or desiccated must receive some of the spray. Spray coverage can be enhanced by using proper nozzles and adjuvants. Research indicates that cone type nozzles usually provide better foliar coverage than flat fan or flood jet nozzles. Two equally spaced nozzles per row should give adequate coverage in most situations.

Adjuvants enhance the ability of an agrichemical to enter a substrate or penetrate a surface. These are known as “penetrants”. They also increase the area that a droplet of a given volume of spray mixture will cover on a target. These are called “spreaders”. Products such as Syl-Tac©, Hasten©, and Super Spread 7000 have the ability to both penetrate and spread.

It is important to realize that crop conditions have effects on crop responses to harvest aid treatments that are not always predictable. Each field can present it's own set of criteria. Read labels carefully and ask for assistance in determining where your crop is for termination.

References: Texas Agricultural Extension Service James R. Supak, Professor and Associate Department Head Rober G. Lemon, Assistant Professor Charles Stichler, Extension Agronomist

Articles — Cotton Harvest-Aid Recommendations For The 1997 Crop — Central Texas The Proper Use of Cotton Harvest Aid Chemicals

Syl-Tac© and Hasten© are registered trademarks of Wilbur-Ellis Company.
Cyclone Max© is a trademark of Syngenta Crop Protection, Inc.
Prep© and Ginstar© are trademarks of Aventis CropScience.
Boa© is a trademark of Griffin LLC.