Published online by Cambridge University Press: 12 June 2017
Research was conducted at two sites during 1991 and 1993 at Brandon, MB to determine if sodium bicarbonate antagonizes clethodim or quizalofop efficacy and if ultraviolet light is a factor in any antagonism. Sodium bicarbonate in the spray solution reduced the efficacy of clethodim. However, removal of ultraviolet light partially reversed sodium bicarbonate antagonism of clethodim activity with all adjuvants except crop oil concentrate with or without ammonium sulfate. Amigo, crop oil concentrate plus ammonium sulfate, and Merge were the most effective adjuvants for clethodim with distilled water. However, only the adjuvant crop oil concentrate plus ammonium sulfate overcame sodium bicarbonate antagonism of clethodim. Enhance increased the activity of clethodim when sodium bicarbonate was present in the spray solution but overall was not as effective an adjuvant as crop oil concentrate plus ammonium sulfate. Sodium bicarbonate in the spray solution did not reduce quizalofop efficacy.