Woollyleaf Bursage (Ambrosia grayi) Management in Transgenic Cotton on the Texas Southern High Plains

Abstract

Field studies were established in 1998 and repeated in 1999 to evaluate woollyleaf bursage management in glyphosate- and bromoxynil-tolerant cotton.  Glyphosate and bromoxynil, applied three times during the growing season, were evaluated with and without in-season cultivation.  Glyphosate alone and in combination with cultivation and bromoxynil with cultivation controlled woollyleaf bursage greater than 70% after one season and greater than 90% after two seasons.  Glyphosate treatments reduced woollyleaf bursage density >88% after two years.  Weed control systems in both glyphosate- and bromoxynil-tolerant cotton increased yields and net returns over weed control costs compared to cultivation alone for both years of this study.