Tolerance of Four Dry Bean Market Classes to Pre-Emergence Applications of Sulfentrazone

Abstract

Ontario dry bean growers are currently limited to ALS inhibitor herbicides for soilapplied broadleaf weed control; therefore another mode of action is needed. Sulfentrazone is a PPO inhibitor herbicide that has activity on some annual grass and broadleaf weed species. Four field trials were conducted over two years (2014, 2015) to determine the tolerance of four commonly grown dry bean market classes (adzuki, kidney, small red Mexican and white bean) to PRE applications of sulfentrazone at 140, 210, 280 and 420 g·ai·ha -1 . Crop injury, plant height, plant density, shoot biomass, seed moisture content and yield were examined. Sulfentrazone (420 g·ai·ha -1 ) caused up to 74%, 22%, 30%, and 57% injury in adzuki, kidney, small red Mexican and white bean, respectively. Plant density, height and yield were not reduced for kidney or small red Mexican bean. Sulfentrazone (420 g·ai·ha -1 ) reduced white bean plant density, height and yield by 28%, 29% and 29%, respectively; and reduced adzuki bean plant density, height and yield by 51%, 34% and 57%, respectively. Overall, kidney and small red Mexican bean were the most tolerant to sulfentrazone, followed by white bean, and then adzuki. This study determined sulfentrazone applied PRE is safe for Ontario kidney bean and small red Mexican bean crops.