Sensitivity of Dry Bean to Dimethenamid-p, Saflufenacil and Dimethenamid-p/Saflufenacil

Abstract

There is limited information on the sensitivity of dry bean to dimethenamid-p, saflufenacil and a preformulated mixture of dimethenamid-p/saflufenacil. Field trials were conducted at Exeter and Ridgetown, ON, Canada in 2012 and 2013 to evaluate the tolerance of four market classes of dry bean to dimethenamid-p, saflufenacil and dimethenamid-p/saflufenacil applied preemergence (PRE) at the 1X and 2X manufacturer’s recommended rate in soybean. Dimethenamid-p, saflufenacil and dimethenamid-p/saflufenacil applied PRE caused 0% - 2%, 20% - 31% and 34% - 45% injury in dry bean, respectively. Dimethenamid-p (220 and 440 g ai ha - 1 ) caused no adverse effect on plant stand, shoot dry weight, height and yield of black, white, adzuki and kidney bean. Saflufenacil (25 and 50 g ai ha - 1 ) or dimethenamid-p/saflufenacil (245 and 490 g ai ha - 1 ) reduced plant stand 53% - 70%, shoot dry weight 61% - 81%, height 26% - 48% and yield 40% - 61% of black and white bean. However, saflufenacil applied alone or in combination with dimethenamid-p at the 1X or 2X rates caused no adverse effect on plant stand, shoot dry weight, height and yield of adzuki and kidney bean except with dimethenamid-p/saflufenacil at the 2X rate which reduced plant stand 38% in kidney bean, shoot dry weight 46% in adzuki bean and 42% in kidney bean, and yield 29% in kidney bean. Based on these results, saflufenacil and dimethenamid-p/saflufenacil applied PRE at the proposed rate of 25 and 245 g ai ha - 1 , respectively does have an adequate margin of crop safety for weed management in black and white bean. Further research is needed to ascertain the margin of crop safety in kidney and adzuki bean.