Field studies were conducted in 1987 and 1988 to investigate the control of common lambsquarters in pea and snap bean following preplant incorporated, preemergence, and postemergence applications of imazethapyr at 36 to 69 g ai/ha. The residual activity of imazethapyr on rotational crops of sweet corn, grain sorghum, and cucumber was evaluated. All rates of imazethapyr provided good (>80% initially) control of common lambsquarters. Although imazethapyr caused some injury to both pea and snap bean, yields were not reduced except for snap bean following postemergence applications. Imazethapyr residues resulting from the applications of 36 to 69 g/ha caused visible injury and fresh weight reductions to all three rotational crops.
