Ginstar was applied with a self-propelled ground sprayer in 1991, 1992, and 1993 to small replicated test plots of furrow irrigated cotton in the Southern Rolling Plains of Texas. Ginstar was applied by airplane to a twenty acre block in 1993. In these four small plots tests and one large block test, Ginstar was equal in its level of leaf defoliation with any currently legal labled harvest aid (as of December 1993) that was tested and significantly higher than the check. Leaf drop still remained high when night temperatures fell in the 50 to 60°F range. The defoliation of the cotton plant was slowed when night temperatures dropped below 60°F. When Ginstar is used at rates above the 0.125 a.i. level, leaf desiccation is significantly higher than the check. However, when applied at the 0.125 and 0.15 a.i. rates the level of leaf desiccation was no different than harvest aids that were tested that are currently labeled for legal application. When compared to the check and all harvest aids tested, Ginstar plots had an equal amount or less regrowth in the terminal and bottom portion of the plant.