North Carolina cotton producers experience perennial problems defoliating cotton. With over 90% of the state's cotton being entirely rainfed, year to year variations result in both lint yield and nitrogen utilization. Additionally, droughts experienced in July and August may be followed by late season rains promoting second growth in late August and September.

Inconsistent response to defoliation treatment may result in cotton when ample nitrogen and water are available, particularly when accompanied by second growth. producers learn that the treatment that worked well last year does not satisfactorily defoliate this year's crop. The leaves are either visually unaffected or dessicated. Frustrated producers resort to untested, complex mixes of several defoliants and adjuvants; a practice that only contributes to the overall confusion. Producers need a more reliable method of harvest preparation.

This research was initiated to assist North Carolina producers choose defoliation treatments systematically, with predictable and desirable results. The study had three specific objectives; 1) Evaluate six selected defoliation treatments under varied environmental conditions; 2) Determine varietal response to these treatments; and, 3) Evaluate petiole nitrate monitoring as a guide to defoliant selection.