Use of harvest aids to terminate and prepare the cotton crop for machine harvest has been an accepted practice for expediting crop maturity, increasing harvest efficiency, and improving lint yield and quality. Many materials have been registered and recommended for use as harvest aids in this country. Def/Folex, Dropp, Harvade, Ginstar, ethephon, Finish, CottonQuik, Leafless, and Aim are some of the most popular products now being used. Proper use of these products is important to ensure the quality of defoliation, boll opening, and regrowth control.

Picker cotton is usually treated with a hormonal or herbicidal defoliant to remove the leaves. Both hormonal and herbicidal defoliants injure the leaf by increasing ethylene production that causes the leaf to fall from the plant, while desiccants are harsher than defoliants and cause injury that leads to rapid moisture loss and drying of the leaves.

Although not exact, timing of harvest aid application is generally guided by such techniques as percent open bolls, the cut boll technique, and nodes above cracked boll. Choice of harvest aids varies with production region, type of harvest, physical, and environmental factors. Nevertheless, most growers use mixtures popular in their area to accomplish some or all of the following actions: defoliation and/or desiccation, boll opening, and regrowth control. Evaluation of a harvest aid alone or in combination with others is extremely important for identifying the optimal rate for the product and/or combinations of products.

The objective of this analysis is to test each harvest aid treatment of a four year defoliation study for its performance and cost effectiveness.