Response of dry beans to halosulfuron applied postemergence

Abstract

Soltani, N., Shropshire, C. and Sikkema, P. H. 2012. Response of dry beans to halosulfuron applied postemergence. Can. J. Plant Sci. 92: 723–728. Four field trials were conducted over a 2-yr period (2009 and 2010) at Exeter and Ridgetown, Ontario, to evaluate the tolerance of adzuki, black, cranberry, kidney, otebo, pinto, Small Red Mexican and white beans to halosulfuron applied postemergence (POST) at 35 and 70 g a.i. ha−1. All treatments including the non-treated control were maintained weed free during the growing season. Halosulfuron applied POST caused as much as 73, 7, 13, 12, 12, 11, 11 and 9% injury in adzuki, black, cranberry, kidney, otebo, pinto, Small Red Mexican (SRM) and white beans, respectively. Halosulfuron applied POST reduced adzuki bean height as much as 52 and 70% at Exeter and Ridgetown, respectively. Plant height was not affected in the other market classes of dry bean evaluated. Halosulfuron POST reduced shoot dry weight of adzuki bean 68% at both rates evaluated. Otebo and SRM bean shoot dry weight were not affected when halosulfuron was applied POST at 35 g a.i. ha−1 but otebo bean shoot dry weight was reduced 12% and SRM bean shoot dry weight was reduced 14% at 70 g a.i. ha−1. Shoot dry weight of black, cranberry, kidney, pinto and white bean was not affected with either rate of halosulfuron. Seed yield of adzuki bean was decreased 58% at 35 g a.i. ha−1 and 68% at 70 g a.i. ha−1 with halosulfuron. White bean yield was not affected with halosulfuron applied POST at 35 g a.i. ha−1 but was reduced 9% at 70 g a.i. ha−1. Seed yield of black, cranberry, kidney, otebo, pinto and SRM bean was not reduced with either rate of halosulfuron. Based on these results, there is not an adequate margin of crop safety for halosulfuron POST in adzuki bean. However, there is potential for POST application of halosulfuron in black, cranberry, kidney, otebo, pinto, SRM and white beans.