Studies were conducted in the Willamette Valley of western Oregon to evaluate the effects of plowing (7.5-15 cm deep) and disking (5-10 cm deep) in peppermint, Mentha piperita L., on the following factors: 1) emergence of adult "mint root borer", Fumibotys fumalis Guenée; 2) suppression of common groundsel, Senecio vulgaris...