Influence of Adjuvants on Interactions of Sethoxydim with Selected Broadleaf Herbicides Used in Corn (Zea mays)

Field experiments were conducted during 1996 and 1998 to determine the effect of atrazine, bentazon, atrazine + bentazon, the amine salt of 2,4-D, and bromoxynil on broadleaf signalgrass and barnyardgrass control when applied in mixture with sethoxydim. Herbicide combinations were applied with crop oil concentrate, crop oil concentrate + ammonium sulfate, or BCH 815. Bentazon and atrazine + bentazon reduced broadleaf signalgrass and barnyardgrass control by sethoxydim. Bromoxynil reduced barnyardgrass control but had no affect on broadleaf signalgrass control. Including ammonium sulfate with crop oil concentrate or substituting BCH 815 for crop oil concentrate increased barnyardgrass and broadleaf signalgrass control by sethoxydim when applied with bentazon. Ammonium sulfate and BCH 815 increased barnyardgrass control when sethoxydim was applied with bromoxynil but did not affect control when sethoxydim was applied with atrazine + bentazon. Atrazine and the ammonium salt of 2,4-D did not reduce barnyardgrass and broadleaf signalgrass control by sethoxydim regardless of adjuvant.