Sweet corn (Zea mays) cultivar tolerance to nicosulfuron

Eleven sweet corn cultivars were evaluated to identify cultivar sensitivity to nicosulfuron in three field studies, conducted over a 2-yr period. Response to nicosulfuron varied, depending on cultivar and application dose. DelMonte 2038 was highly sensitive to nicosulfuron, resulting in very severe injury and in most cases the death of all plants at both locations each year. At Exeter in 1997 and 1998, injury was slight, with no yield reductions on other cultivars. At Simcoe in 1998, five cultivars showed severe visual injury, especially at 50 g ha −1 of nicosulfuron; however, this did not always result in a significant yield reduction. Cultivars with a yield reduction were Elite, GH 1703 and Calico Belle. The cultivars Bonus Bt, Reveille, Krispy-King, GSS 7831 and GH 2690 were classified as fully tolerant to field applications of nicosulfuron showing injury of 5% or less at 25 g ha −1 and with no yield reduction.