Bell Pepper (Capsicum annuum) Tolerance to Imazosulfuron and Thifensulfuron-Methyl

摘要

Greenhouse and field studies were conducted to evaluate bell pepper tolerance to the sulfonylurea herbicides imazosulfuron and thifensulfuron-methyl. Imazosulfuron was applied at 56, 112, 224, 336, or 448 g ai ha(-1). Thifensulfuron-methyl was applied at 2.6, 5.3, 10.5, 21.0, or 31.6 g ai ha(-1). In the greenhouse over 2 yr, bell pepper injury due to imazosulfuron POST ranged from 12 to 27. Reductions in plant height and numbers of nodes, buds, flowers, and fruits were generally minor or not observed. Injury from thifensulfuron-methyl POST ranged from 40 to 60 in the greenhouse. Similar trends were observed for leaf chlorosis and distortion. Thifensulfuron-methyl tended to decrease numbers of buds, flowers, and fruits in the greenhouse. In the field at three sites, bell pepper injury due to imazosulfuron applied POST-directed (POST-DIR) was less than 10 at all rating times, and height and yield were not affected. Total and marketable yield averaged 40,300 and 35,810 kg ha(-1), respectively, across environments and years. Bell pepper injury from thifensulfuron-methyl applied POST-DIR in the field was less than 20 with all rates and less than 10 when rates less than 10.6 g ai ha(-1) thifensulfuron-methyl were applied. Bell pepper stand (plants ha(-1)) or height was not affected by thifensulfuron-methyl. Thifensulfuron-methyl did not affect total bell pepper yield (39,310 kg ha(-1) averaged across environments); however, reductions in Fancy grade yield were observed. No. 1 and cull yield grades tended to increase with increasing thifensulfuron-methyl rate, apparently compensating for lost Fancy yield.