Quackgrass (Agropyron repens) Control in Potatoes (Solanum tuberosum) by Fluazifop

In greenhouse and field studies, fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid} controlled quackgrass [Agropyron repens(Beauv.) # AGRRE] in potato (Solanum tuberosumL. ‘Russet Burbank’). Quackgrass control with fluazifop at 0.25 and 0.5 kg ai/ha in the greenhouse was greatest with application at the two-leaf stage compared with the four-and six-leaf stages. Control was not affected by rhizome length, with similar control obtained of plants grown from 2- and 10-node rhizome pieces. Removal of quackgrass shoots at 6 or 24 h after treatment resulted in decreased control at application rates of 0.25 and 0.5 kg/ha. Fluazifop at 0.5 kg/ha controlled quackgrass treated at the four-leaf stage. The active enantiomer of fluazifop at half the rate of the racemic mixture controlled the quackgrass to the same extent. Fluazifop did not affect potato yield.