Dates of Herbicide Application for Summer Weed Control in Turf

Abstract

Six herbicides were applied monthly from February to May for control of large crabgrass [Digitaria sanguinalis (L.) Scop.] and goosegrass [Eleusine indica (L.) Gaertn.]. Bensulide [O,O-diisopropyl phosphorodithioate S-ester with N-(2-mercaptoethyl)benzenesulfonamide] applied in February or March controlled at least 70% of large crabgrass, whereas, treatments applied in April resulted in similar control at two of three locations. All herbicides failed to control large crabgrass when applied in May. Oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-δ2-1,3,4-oxadiazolin-5-one] and butralin [4-(1,1-dimethylethyl)-N-(1-methylpropyl)-2,6-dinitrobenzenamide] controlled goosegrass for the full season when applied in March or April. Oxadiazon also controlled goosegrass when applied in May.