Sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, RO-13-8895 {acetone-O-[d-2-[p-[α,α,α-trifluoro-p-tolyl-oxy]phenoxy] propionyl] oxime}, and KK-80 {4-[4-[4-(trifluoromethyl)phenoxy] phenoxyl]-2-pentenoic} were evaluated for potential use for controlling quackgrass [Agropyron repens (L.) Beauv., # AGRRE] in perennial ryegrass (Lolium perenne L. ‘NK200’), smooth bromegrass (Bromus inermis Leyss. ‘Sac’), orchardgrass (Dactylis glomerata L. ‘Nordstern’), timothy (Phleum pratense L. ‘Climax’), Kentucky bluegrass (Poa pratensis L. ‘Park’), Reed canarygrass (Phalaris arundinaceae L. ‘Rise’), meadow fescue (Festuca elatior L.), and red fescue (Festuca rubra L.). The three herbicides, when applied postemergence at 1.1 kg ai/ha, caused severe injury to all species except red fescue. ‘Pennlawn’, ‘Ruby’, ‘Dawson’, MN67123, MN673, and MN6354 red fescue entries were tolerant to the three herbicides in both greenhouse and field experiments. Sethoxydim and RO-13-8895 effectively controlled quackgrass in Pennlawn red fescue, but KK-80 was not effective.
