Forage Quality and Animal Performance as Influenced by Quackgrass (Agropyron repens) Control in Alfalfa (Medicago sativa) with Pronamide

Abstract

Fall applications of pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide] control or suppress quackgrass [Agropyron repens(L.) Beauv.] in established alfalfa (Medicago sativaL.). Studies were initiated to evaluate benefits of pronamide usage in areas where quackgrass is a problem. Alfalfa swards severely infested with quackgrass were treated with pronamide. Forage quality of first cutting alfalfa was significantly improved with pronamide usage, but second and third cutting forage quality was not greatly affected. First cutting hay from pronamide-treated and untreated areas was fed to goats and dairy cows in feeding trials. Animal intake of total forage dry matter, digestible dry matter, and digestible crude protein was increased with pronamide usage. A reduction in need for supplemental protein, an increase in efficiency in dry matter conversion into milk, and a 20% increase in milk production resulted from controlling quackgrass in alfalfa with pronamide.