CLOMAZONE FOR WEED-CONTROL IN TRANSPLANTED COLE CROPS (BRASSICA-OLERACEA)

Experiments were conducted at Lexington and Quicksand, KY,in 1989 and 1990 to determine the effect of preplant incorporated clomazone on wee d control, crop injury, and yield of broccoli, cauliflower, green cabb age, red cabbage, and pak choi. Oxyfluorfen and trifluralin were inclu ded as standard treatments. Greater than 80% weed control was observed at both locations with 0.8 kg ai ha(-1) clomazone, with the exception of smooth pigweed at Lexington. Ah clomazone treatments caused crop i njury 2 WAT. Injury was still evident 8 WAT at clomazone rates of 1.7 and 3.4 kg ha(-1), but was minor with rates of 0.8 kg ha(-1) or less o n broccoli, cauliflower, and red cabbage. Injury was less at Quicksand in both years and seasons over all clomazone rates, most likely due t o higher soil organic matter content. Yields of broccoli and cauliflow er treated with 0.8 kg ha(-1) clomazone were similar to yields with ox yfluorfen on a 3% organic matter soil at Lexington in 1989. However, c lomazone at 0.8 kg ha(-1) at Lexington reduced 1989 spring yields of g reen cabbage, red cabbage, and pak choi and 1990 spring yields of all cole crops as compared to oxyfluorfen. Clomazone at 0.8 kg ha(-1) at Q uicksand reduced yield of green cabbage and pak choi in spring 1990 on ly on a 5.2% organic matter soil. Fall yields of broccoli and cauliflo wer in both years were not reduced by clomazone at 0.8 kg ha(-1) or le ss at either location. Our studies indicated potential for utilization of clomazone on cole crops in higher organic matter soils, especially if some early season crop injury and occasional yield loss can be tol erated.