Weed control and economic returns with postemergence herbicides in narrow-row soybeans (Glycine max).

Field studies were conducted at three sites in 1993 and 1994 to evaluate weed control, crop response, and economic returns to 0.5 X and 1 X postemergence rates of chlorimuron, chlorimuron plus quizalofop, bentazon plus acifluorfen, fluazifop plus fenoxaprop, imazethapyr, and imazethapyr plus clethodim in no-till narrow-row soybean production. Common lambsquarters, ivyleaf morningglory, and common ragweed were controlled equally with 0.5 X rates applied early postemergence and 1 x rates applied mid-postemergence. Control of giant foxtail, large crabgrass, and common cocklebur was generally greater with 1 X rates mid-postemergence than with 0.5 X rates early postemergence. Soybean yields were equivalent with 0.5 X and 1 X rates. Soybean yields and net income were highest with 1 X and 0.5 X rates of chlorimuron plus quizalofop and imazethapyr plus clethodim, and metolachlor preemergence (PRE) followed by 0.5 X bentazon plus acifluorfen.