White Bean Sensitivity to Preemergence Herbicides

White bean producers have a limited number of herbicide options available for annual grass and broadleaf weed control. Tolerance of two white bean cultivars to preemergence (PRE) applications ofS-metolachlor,S-metolachlor + imazethapyr, flumetsulam +S-metolachlor, cloransulam-methyl, clomazone, clomazone + imazethapyr, and clomazone +S-metolachlor at the maximum labeled rate in soybean (1×) and twice the labeled rate (2×) were studied at two Ontario locations (Exeter and Ridgetown) in 2001 and 2002.S-Metolachlor, clomazone, and clomazone +S-metolachlor generally had no negative effect on plant height, dry weight, maturity, and yield.S-Metolachlor + imazethapyr and clomazone + imazethapyr reduced plant height, dry weight, and yield as much as 21, 42, and 24%, respectively. Flumesulam +S-metolachlor and cloransulam-methyl reduced plant height, dry weight, and yield as much as 39, 58, and 43%, respectively. White beans are tolerant to PRE applications ofS-metolachlor, clomazone, and clomazone +S-metolachlor. White beans are sensitive to PRE applications ofS-metolachlor + imazethapyr, flumetsulam +S-metolachlor, clomazone + imazethapyr, and cloransulam-methyl.