Abstract

There is little information on the tolerance of dry bean to pendimethalin applied preplant incorporated (PPI) or preemergence (PRE). Five field studies were conducted over a two-year period (2009 and 2010) in major dry bean growing areas in Ontario, Canada to evaluate tolerance of black, cranberry, kidney, and white bean to the pendimethalin applied PPI or PRE at 1080 and 2160 g ai ha^-1. There was minimal injury in various market classes of dry bean with pendimethalin applied PPI or PRE at 1080 or 2160 g ai ha^-1 1 and 2 weeks after emergence (WAE). However, pendimethalin applied PRE caused slightly greater injury than pendimethalin applied PPI at 4 WAE.  Pendimethalin applied PPI or PRE at 1080 or 2160 g ai ha^-1 had no adverse effect on height of black, cranberry, kidney, and white bean except with pendimethalin at 2160 g ai ha^-1 which decreased plant height 2% at Exeter and Ridgetown in 2009 and 2010. Pendimethalin applied PPI or PRE at 1080 or 2160 g ai ha^-1 had no adverse effect on shoot dry weight of black, cranberry, kidney, and white bean. Yield of black, cranberry, kidney, and white bean was not adversely affected with pendimethalin applied PPI or PRE at 1080 or 2160 g ai ha^-1 but there were differences between seed yield of various market classes of dry bean. Based on these results, there is an adequate margin of crop safety for pendimethalin applied PPI or PRE at the proposed rate of 1080 g ai ha^-1 in black, cranberry, kidney, and white bean in Ontario.

Key words: Black bean, cranberry bean, kidney bean, navy bean, pendimethalin, Phaseolus vulgaris L., white bean.