Evaluation of glufosinate-resistant corn (Zea mays) and glufosinate: Efficacy on annual weeds

Field studies were conducted in 1996 and 1997 at Belleville and Pawnee, IL, to evaluate single and sequential applications of glufosinate on tolerance of glufosinate-resistant corn and annual weed control. Glufosinate caused 0 to 13% corn injury 7 days after treatment (DAT) and 0 to 6% corn injury 2 8 DAT. Injury was characterized as stunting with glufosinate. Glufosinate a t 400 to 1,200 g ai/ha did not reduce final corn height or grain yield. At Pawnee in both years and at Belleville in 1996, a single application of glu fosinate at 400 g/ha controlled giant foxtail, velvetleaf, ivyleaf morningg lory, and common lambsquarters 85 to 100%. At Belleville in 1997, sequentia l applications of glufosinate provided greater weed control (87 to 100%) th an a single application (0 to 63%) because of weed emergence after applicat ion. Weed control with a single application of glufosinate or with nicosulf uron plus bromoxynil was similar at both locations. Height and grain yield of glufosinate-resistant corn were not different from that of glufosinate-s usceptible corn (isoline of glufosinate-resistant corn).