Sulfentrazone Carryover to Vegetables and Cotton

Abstract

Sulfentrazone is commonly used for weed control in soybeans and tobacco, and vegetable crops and cotton are often rotated with soybeans and tobacco. Studies were conducted to evaluate the potential for sulfentrazone to carryover and injure several vegetable crops and cotton. Sulfentrazone was applied PRE to soybean at 0, 210, 420, and 840 g ai/ha before planting bell pepper, cabbage, cotton, cucumber, onion, snap bean, squash, sweet potato, tomato, and watermelon. Cotton, known to be susceptible to sulfentrazone carryover, was included as an indicator species. Cotton injury ranged from 14 to 18% with a 32% loss of yield in 1 of 2 yr when the labeled use rate of sulfentrazone (210 g/ha) was applied to the preceding crop. High use rates of sulfentrazone caused at least 50% injury with yield loss ranging from 36 to 100%. Bell pepper, snap bean, onion, tomato, and watermelon were injured < 18% by sulfentrazone at 840 g/ha. Squash was injured < 3% and < 36% by sulfentrazone at 210 and 840 g/ha, respectively. Yield of these crops was not affected regardless of sulfentrazone rate. Cabbage and cucumber were injured < 13% by sulfentrazone at 210 and 420 g/ha, and yields were not affected. Sulfentrazone at 840 g/ha injured cabbage up to 46% and reduced yield in 1 of 2 yr. Sulfentrazone injured cucumber up to 63% and reduced yield of No. 2 grade fruits. Sulfentrazone at 210 and 420 g/ha injured sweet potato < 6% and did not affect yield. Sulfentrazone at 840 g/ha injured sweet potato 14% and reduced total yield 26%. Our results suggest little to no adverse effect on bell pepper, cabbage, cucumber, onion, snap bean, squash, sweet potato, tomato, or watermelon from sulfentrazone applied at registered use rates during the preceding year.