Weed Control in Narrow and Wide-Row Soybeans

Abstract

Field studies were conducted over a 3-yr period to evaluate weed control systems for soybeans [Glycine max(L.) Merr.] grown in 18- and 76-cm rows. Combinations of herbicides satisfactorily controlled a broad spectrum of annual grass and broadleaf weeds in soybeans grown in 76-cm rows with cultivation and in 18-cm rows without cultivation. Where a single herbicide treatment was used to control only annual grasses, the 76-cm rows (which were cultivated once) yielded from essentially the same as 18-cm rows up to almost 50% more than the 18-cm rows, which received no cultivation, depending on the year and broadleaf weed infestation. However, where herbicide combinations were used to effectively control all weeds, soybeans in 18-cm rows averaged up to 9% higher yields than those in the 76-cm rows.