ROTATIONAL CROP RESPONSE TO CHLORIMURON, CLOMAZONE, AND IMAZAQUIN APPLIED THE PREVIOUS YEAR

Experiments to determine effects of chlorimuron, clomazone, and imazaquin applied the year before planting corn, cotton, and sorghum were conducted at three locations in Georgia. Corn injury was < 20% in 1987 and 1988 and yield was not affected. In 1988, imazaquin applied at a high rate or sequentially the previous year to late-planted soybeans injured corn more than applications to the early-planted soybeans. Cotton was the most sensitive crop to herbicides applied the previous year. However, seed cotton yield was not decreased due to herbicides applied the previous year. Sorghum growth and yield 8 weeks after planting was not affected by soybean herbicide application the previous year. Sicklepod, corn, and wheat bioassays did not detect any of the herbicides in soil samples obtained the season after treatment. Bioassays accurately predicted potential injury in corn and sorghum but not cotton.