Soybean and Weed Response to Dinoseb and Chloroxuron Applied Topically

Abstract

Two herbicides, the alkanolamine salts of 2-sec-butyl-4,6-dinitrophenol (dinoseb) and 3-[p-(p-chlorophenoxy) phenyl]-1,1-dimethylurea (chloroxuron), were compared for their effects on soybean [Glycine max (L.) Merr., ‘Lee’] when applied topically. In initial studies, chloroxuron was damaging when applied twice to soybean and reduced yields in one of the two year's studies. In a third year's work, direct comparisons of topical applications of dinoseb and chloroxuron showed that soybean injury increased with increased rate of material at each soybean growth stage with the most severe initial damage in the two-trifoliate stage. Recovery was rapid with few significant yield decreases occurring. Chloroxuron was more effective in controlling the broadleaf weeds present. Both herbicides were most effective when weeds were in the seedling stage of growth.