Residues and Efficacy With Fluazifop-P in Alfalfa (Medicago sativa)

Abstract

Fluazifop-P, applied in the spring or fall and pronamide, applied in the fall only, reduced quackgrass infestation in established alfalfa and increased the dry matter yield of alfalfa. Herbicides did not improve alfalfa in vitro digestibility or crude protein content. Average residues of fluazifop-P in alfalfa treated with rates of 0.25 or 0.5 kg ai ha–1, were 0.1 mg kg–1when harvested 280 d after application, and 0.06 mg kg–1when harvested 295 d after application. Average residues in alfalfa harvested 41 and 55 d after application were 0.13 mg kg–1and 0.1 mg kg–1, respectively, with a 0.25 kg ha–1treatment and 0.19 mg kg–1and 0.05 mg kg–1, respectively, with a 0.5 kg ha–1treatment.