Evaluation of postemergence herbicides for kochia control in spring wheat

A trial was conducted to evaluate postemergence herbicide combinations for control of kochia in spring wheat.  Spring wheat ‘Lang’ was planted on May 1, 2023 using a no-till drill at a depth of 2 inches; wheat emerged on May 9.  At time of planting, soil conditions were dry due to limited rainfall during the month of April 2023 and there were few weeds present. In the two weeks following planting, over 5 inches of rainfall occurred which allowed for emergence of both crop and weeds.  All treatments in this trial contained the active ingredient fluroxypyr.  Fluroxypyr alone (Starane Ultra) provided just 75% control at 68 days after application. Similarly, Widematch (fluroxypyr plus clopyralid), WideMatch plus MCPE, and Carnivore (fluroxypyr plus MCPA plus bromoxynil) controlled kochia at 75 to 77%. Most other treatments controlled kochia at 80 to 88%, with the exception of Huskie FX, where kochia control was 97%. Wheat yield ranged from 96 to 106 bu/A and there was no significant difference in wheat yield due to herbicide treatment, even when no herbicide was applied.  The lack of rainfall during April delayed the emergence of kochia in this trial until after wheat had been planted and was already emerged.  This resulted in wheat having a competitive advantage which it maintained throughout the growing season due to the above average rainfall that occurred during the 2023 cropping season.  Wheat yield, which often surpassed 100 bu/A was also much higher than the average for this location which is typically around 40 bu/A.