Soybean (Glycine max) Tolerance to Simulated Drift of Nicosulfuron and Primisulfuron

Abstract

Soybean response to simulated drift of the corn herbicides nicosulfuron and primisulfuron applied POST at 10 to 50% (3.5 to 17.4 and 4.0 to 20.2 g ai ha−1, respectively) of the total rates at the V3 and R1 growth stages was evaluated in field studies in 1991 and 1992. Primisulfuron reduced soybean height and increased leaf chlorosis, cupping, and necrosis more than nicosulfuron with both applications at all five rates. The symptoms of injury caused by both herbicides often increased linearly with increasing rate. At 50% of label rate, primisulfuron reduced height 75% and decreased yield 58%. Nicosulfuron reduced soybean height as much as 27%, but did not reduce seed yield either year. Height reduction, leaf chlorosis, cupping, and necrosis were correlated with yield loss caused by primisulfuron.