News Release 

When, how, and why to use harvest aids

American Phytopathological Society

Science Business Announcement

When we talk about defoliants, we're actually talking about harvest aids, according to Extension cotton agronomist Steve Brown. Harvest aids are tools used by cotton farmers to accelerate the natural processes of leap drop and boll opening and thereby improve harvest efficiency, expedite once-over harvest, minimize trash in the harvester, minimize lint stain, and deliver quality cotton. These aids might also serve other functions, including leaf removal, regrowth inhibition, weed management, and boll opening.

In the freely available presentation "Preparing for Defoliation," Brown outlines the overall purpose and function of harvest aids without providing specific recommendations, as different regions require different strategies. He discusses the importance of the timing of harvest aid application and recommends several methods, including the standard approach of waiting until 60% of the cotton is opened. He also advocates for cut and confirm, also known as the sharp knife technique. If the boll is difficult to cut through, farmers can confidently apply harvest aids.

Brown recommends that farmers keep abreast of performance in their areas to determine local preferred products and rates. Moreover, Brown recommends that farmers combine products for better results. Farmers should also consider harvest capacity, labor availability, and the weather when determining when to apply harvest aids. Conditions during the first 3 to 6 days after application significantly affect performance; extreme temperatures and heavy rains can decease harvest aid efficacy.

This 28-minute presentation is available through the "Focus on Cotton" resource on the Plant Management Network. This resource contains more than 100 webcasts, along with presentations from a number of conferences, on a broad range of aspects of cotton crop management: agronomic practices, diseases, harvest and ginning, insects, irrigation, nematodes, precision agriculture, soil health and crop fertility, and weeds. These webcasts are available to readers open access (without a subscription).

The "Focus on Cotton" homepage also provides access to "Cotton Cultivated," a resource from Cotton Incorporated that helps users quickly find the most current cotton production information available. These and other resources are freely available courtesy of Cotton Incorporated at


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