Nader Soltani*, Christy Shrops
Abstract
Six field trials (three to evaluate broadleaved weed control and three to evaluate grass weed control) were conducted from 2006 to 2008 in Ontario, Canada to evaluate the co-application of postemergence herbicides with dimethoate or cyhalothrin-lambda insecticides for control of annual broadleaved and grass weeds in white bean. Bentazon, fomesafen and bentazon plus fomesafen provided 3-62, 73-100 and 68-99% control of redroot pigweed, 34-98, 81-100 and 88-100% control of common ragweed, 78-85, 38-56 and 72-80% control of common lambsquarters, and 81-100, 97-100 and 96-100% control of wild mustard, respectively. Sethoxydim and quizalofop-p-ethyl provided 84-98 and 74-98% control of green foxtail, 91-98 and 91-97% control of giant foxtail, respectively. The addition of dimethoate or cyhalothrin-lambda insecticides to bentazon, fomesafen or bentazon plus fomesafen generally did not have any adverse effect on control, density and biomass of redroot pigweed, common ragweed, common lambsquarters and wild mustard. The addition of dimethoate or cyhalothrin-lambda to sethoxydim or quizalofop-p-ethyl decreased control of green foxtail and giant foxtail as much as 6% under some environments but did not have any significant effect on green foxtail and giant foxtail density and biomass. Injury in white bean was minimal (6% or less) with no adverse effect on yield in both studies. These studies conclude that dimethoate or cyhalothrin-lambda can be tankmixed with bentazon, fomesafen, bentazon plus fomesafen, sethoxydim or quizalofop-p-ethyl when the optimum application timing of theses herbicides and insecticides coincide with no adverse effect on weed control or white bean yield.