SICKLEPOD (SENNA-OBTUSIFOLIA) INTERFERENCE WITH SOYBEAN (GLYCINE-MAX)CULTIVARS FOLLOWING HERBICIDE TREATMENTS

Three Group V soybean cultivars were grown in the greenhouse to quanti fy interference when planted al. various intervals with sicklepod, and the effects of chlorimuron and imazaquin POST on this interspecific i nterference, Soybean shoot height or fresh weight was not affected by sicklepod interference when sicklepod was planted 10 d after soybean i n most cases. 'Asgrow 5979' soybean shoot height was not reduced when planted with sicklepod, but was reduced when planted 10 d after sickle pod and no herbicide treatment was added. When sicklepod was planted 1 0 d before Asgrow 5979 and '9592 Pioneer' soybean, shoot height was re duced more than 'Hutcheson,' regardless of herbicide treatment. The cu ltivar 9592 Pioneer was more effective in reducing sicklepod shoot hei ght than Asgrow 5979 when no herbicide treatment was used, Chlorimuron or imazaquin had Little or no effect on sicklepod interference with s oybean under these conditions.