Series/Report Number: COARC2015

Abstract: There have been ongoing concerns by growers and fieldmen in about herbicides used in peppermint production carrying over when rotating into Kentucky bluegrass or winter wheat. Symptoms generally appear as Sinbar damage despite lowered rates later in production years with no Sinbar applied the final year of production. Of concern is whether alternative herbicides used in the final year or two in combination with Sinbar is creating a synergistic effect that is causing the observed damage. A research project was established to evaluate four herbicides applied alone and in various combinations to address these concerns. As of early December, no observable effect of these twenty herbicide treatments on Kentucky bluegrass or winter wheat stands has been observed.