Annual grass control in alfalfa (Medicago sativa) with postemergence graminicides.
Field trials were conducted in 1982-88 in Virginia (on loam at or near Blacksburg and on silt loam at Stuarts Draft) to evaluate BAS 517 [cycloxydim], CGA 82725 [chlorazifop], clethodim, cloproxydim, fenoxaprop, fluazifop, fluazifop-P, haloxyfop, paraquat, quizalofop, SC-1084, [methyl-3-hydroxy-4-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]pentanoate], sethoxydim ± thifensulfuron and terbacil for the control of annual grasses in lucerne cv. WL 311 and Saranac. Herbicides were applied to lucerne and grasses 2-30 cm in height after the 1st and/or 2nd cuttings. Overall, the herbicides were highly effective in controlling Panicum dichotomiflorum, Setaria faberi, Echinochloa crus-galli and Digitaria sanguinalis. Lucerne yields were not increased with herbicide treatments in several experiments. Only paraquat, applied later than recommended after cutting in 1 experiment, and sethoxydim + thifensulfuron at 1 location, reduced lucerne yields.