Crop Protectants and Herbicides for Orchardgrass-Alfalfa Establishment

One greenhouse and two field experiments were conducted to determine if crop protectants used in conjunction with herbicides would permit weed-free establishment of orchardgrass ( Dactylis glomerata L. ‘Potomac’) with alfalfa ( Medicago sativa L. ‘WL 307’). Herbicides used were EPTC ( S -ethyl dipropylthiocarbamate) and butam [2,2-dimethyl- N -(1-methylethyl)- N -(phenylmethyl)propanamide] plus cyprazole { N -[5-(2-chloro-1,1-dimethylethyl)-1,3,4 thiadiazol-2-yl] cyclopropanecarboxamide}. These experiments revealed that banded activated charcoal allowed limited orchardgrass establishment with a herbicide but did not result in consistently better orchardgrass stands than the untreated control. Orchardgrass was not protected from herbicide injury by 1,8-naphthalic anhydride (NA) or R-25788 ( N,N -diallyl-2,2-dichloroacetamide). The butam plus cyprazole mixture consistently controlled grass and broadleaf weeds as effectively as EPTC.