Response of several transplanted pepper cultivars to variable rates and methods of application of clomazone

Field studies were conducted to evaluate the tolerance of several pepper (Capsicum annuum L.) cultivars to the herbicide clomazone. Peppers tested included the bell cultivars Yolo Wonder and Jupiter; the banana cultivar Sweet Banana; and the pungent cultivars Jalapeno and Red Chili. Treatments were clomazone at 0.56 or 1.12 kg.ha(-1) a.i. applied either preplant incorporated (PPI), pretransplant (PRE-T), or posttransplant (POS-T) on the day of transplanting, plus a nontreated control. Clomazone at 1.12 kg.ha(-1) a.i, PPI and PRE-T significantly injured (bleaching or chlorosis of foliage) 'Sweet Banana' (40% and 20%,respectively) and 'Red Chili' (30% and 18%,respectively) in 1993 in early-season evaluations, but this injury was transient and did not significantly affect total fruit number or yield. Injury to any cultivar from POS-T clomazone at 0.56 and 1.12 kg.ha(-1) a.i. was nonsignificant, Overall, tolerance to clomazone was excellent for all treatments and across all cultivars, Yield was not reduced significantly by any treatment. Chemical names used: 2-[(2-chlorophenyl) methyl]-4, 4-dimethyl-3-isoxazolidinone (clomazone).