Snap Bean (Phaseolus vulgaris) and Common Lambsquarters (Chenopodium album) Response to Acifluorfen

Abstract

Field studies were conducted for 3 yr to determine the foliar activity of acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} for control of common lambsquarters (Chenopodium albumL. # CHEAL) in snap beans (Phaseolus vulgarisL. ‘Provider’ in 1983 and 1985 and ‘Green Crop’ in 1984). Control of 1 to 7 cm tall common lambsquarters varied between 75 and 100% with 0.28 kg ai/ha acifluorfen and frequently increased linearly with increases in acifluorfen rates to 0.84 kg/ha. Snap bean injury occurred each year and in 1985 was influenced by acifluorfen rate, stage of snap bean growth, and surfactant. Snap bean yields in 1983 were reduced linearly with increases in acifluorfen rates and in 1985 were reduced more from applications at the 1- to 2-trifoliolate leaf stage than at the 4- to 8-trifoliolate leaf stage. In the greenhouse, reductions in snap bean height from acifluorfen were related to application timing, surfactant and cultivar. Fresh weight reduction of snap beans was highest with the cultivar ‘Green Crop’ but was increased to both cultivars by early application timing and the addition of surfactant to the spray mix.