Does a Preharvest Application of Roundup® Improve Cotton Defoliation?

Abstract

Preharvest applications of Roundup improved defoliation and regrowth suppression when used in conjunction with an application of Dropp +Def on Upland cotton in experiments conducted in Buckeye, Maricopa, and Queen Creek, AZ. However, all treatments used provided commercially acceptable defoliation. Preharvest Roundup applications made about two weeks (or one irrigation interval) before the application of Dropp +Def did not reduce seed cotton yields, lint yields, or affect color-grade and fiber characteristics.