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 of S-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 of S-metolachlor, clomazone, and clomazone S-metolachlor. White beans are sensitive to PRE applications of S-metolachlor imazethapyr, flumetsulam S-metolachlor, clomazone imazethapyr, and cloransulam-methyl.
Nomenclature: Clomazone; cloransulam-methyl; flumetsulam; imazethapyr; S-metolachlor; soybean, Glycine max (L.) Merr; white bean, Phaseolus vulgaris L.
Additional index words: Dry beans, herbicide tolerance, preemergence herbicides, white beans.
Abbreviations: DAE, days after emergence; PRE, preemergence; 1× rate, the maximum recommended herbicide labeled rate in soybean; 2× rate, twice the maximum recommended herbicide labeled rate in soybeans.