Characterizing goosegrass and crabgrass in management intensive grazing dairies

Abstract

The state of Georgia has seen a rapid increase in the number of cows raised in pasture-based dairy systems. Recently unforeseen summer annual weed problems have emerged. Goosegrass (EleusineindicaL. Gaertn.) and crabgrass (DigitariasanguinalisL.Scop.) compete directly with bermudagrass (CynodondactylonL.Pers.). This competition may weaken forage stands thus; an experiment was conducted to determine if competition from winter annual forage grasses inhibited establishment of goosegrass and crabgrass. Summer annual weed suppression was greater following annual ryegrass (LoliummultiflorumL.) than oats (AvenasativaL.) or cereal rye (SecalecerealL.) under irrigation. Also the effect of goosegrass population density and defoliation strategy on bermudagrass biomass was examined and a decrease in bermudagrass biomass was seen where goosegrass was not harvested and as goosegrass population density increased. A third component of the research indicated that cell wall content of goosegrass was consistently less than that of bermudagrass and likely not a reason for grazing preferences for bermudagrass.