Sicklepod (Senna obtusifolia) Interference with Soybean (Glycine max) Cultivars Following Herbicide Treatments

Abstract

Three Group V soybean cultivars were grown in the greenhouse to quantify interference when planted at various intervals with sicklepod, and the effects of chlorimuron and imazaquin POST on this interspecific interference. Soybean shoot height or fresh weight was not affected by sicklepod interference when sicklepod was planted 10 d after soybean in most cases. ‘Asgrow 5979’ soybean shoot height was not reduced when planted with sicklepod, but was reduced when planted 10 d after sicklepod and no herbicide treatment was added. When sicklepod was planted 10 d before Asgrow 5979 and ‘9592 Pioneer’ soybean, shoot height was reduced more than ‘Hutcheson,’ regardless of herbicide treatment. The cultivar 9592 Pioneer was more effective in reducing sicklepod shoot height than Asgrow 5979 when no herbicide treatment was used. Chlorimuron or imazaquin had little or no effect on sicklepod interference with soybean under these conditions.