Annual Grass Control in Alfalfa (Medicago sativa) with Postemergence Graminicides

Abstract

Field experiments were conducted during 1982 to 1988 in Virginia to evaluate BAS 517, CGA 82725, clethodim, cloproxydim, fenoxaprop, fluazifop, fluazifop-P, haloxyfop, paraquat, quizalofop, SC-1084, sethoxydim, sethoxydim plus thifensulfuron, and terbacil for control of annual grasses in alfalfa. Herbicides were applied to alfalfa and grasses 2 to 30 cm in height after the first and/or second cuttings. Overall, the herbicides were highly effective in controlling fall panicum, giant foxtail, barnyardgrass, and large crabgrass. Alfalfa yields were not increased with herbicide treatments in several experiments. Only paraquat, applied later than recommended after cutting in one experiment, and sethoxydim plus thifensulfuron at one location reduced alfalfa yields.