Abstracts Biological Sciences

Glufosinate-tolerant cotton: tolerance and weed management

by Lesli Kristen Blair

Field studies conducted in 1997 and 1998 examined plant growth and development, yield and fiber quality of glufosinate-tolerant cotton. Regardless of glufosinate application rate, number of applications, or cotton growth stage at application, no visual injury nor adverse effects on cotton development, yield or fiber quality were observed. Amaranthus palmer! and Proboscidea louisianica control in glufosinate-tolerant cotton using preplant incorporated, preemergence and postemergence-topical herbicide applications with and without cultivation was examined also. Amaranthus palmeri and Proboscidea louisianica was controlled at least 90% when trifluralin preplant incorporated followed by prometryn preemergence followed by glufosinate postemergence was applied. These weeds were controlled 0 to 100% following soil applied herbicides alone and 47 to 99% following glufosinate alone. This research indicated that the transformation events for glufosinate-tolerance in Gossypium hirsutum L. cv. 'Coker 312' were successful and the gene expressing glufosinate-tolerance was expressed throughout the growing season. In addition, Amaranthus palmeri and Proboscidea louisianica control was greater when glufosinate was used in combination with soil applied herbicides as opposed to glufosinate applied alone.