EXP 31130A efficacy and corn (Zea mays) response in western Kansas

Field experiments were conducted over 3 yr at two locations in northwest Kansas to evaluate the efficacy and crop tolerance of EXP 31130A alone and with other herbicides in corn. EXP 31130A alone and in combination with acetochlor, atrazine, or metolachlor controlled kochia and redroot pigweed 93% or greater regardless of location, year, or tillage system. Green foxtail control in 1997 and 1998 was > 90% with EXP 31130A in combination with chloroacetamide herbicides but varied among experiments with EXP 31130A alone. Control of puncturevine with EXP 31130A alone or in tank mixtures was 75% or greater at five of six sites. EXP 31130A alone and in combinations caused minor, early-season, corn leaf bleaching and/or stunting under conventional tillage. However, no injury was detected in no-till systems. In 1996, no-till corn receiving EXP 31130A treatments yielded similarly or up to 29% more than hand-weeded corn. Yields did not differ among treated, untreated, and hand-weeded corn in 1996 under conventional tillage, where weed interference was not as intense as under no-till conditions. Conventional-tillage corn receiving EXP 31130A alone or in tank mixtures in 1997 yielded similarly to hand-weeded corn. Averaged over experiments, corn yield in 1998 increased by 10 to 18% with applications of EXP 31130A alone or in combinations compared to untreated corn.