Fall Herbicide Treatments Reduce Northern Dewberry (Rubus flagellaris) Stem Density in Tall Fescue Pastures and Haylands

Field experiments were conducted from 2008 to 2011 to evaluate the effects of various fall herbicide treatments on northern dewberry (Rubus flagellaris Willd.) control and spring forage yields in tall fescue [Schedonorus phoenix (Scop.) Holub] pastures and haylands. When applied in the fall, all herbicide treatments evaluated in this research, except aminopyralid plus 2,4-D ester (0.12 + 1.0 kg/ha) and triclopyr plus 2,4-D ester (0.56 + 1.1 kg/ha), reduced northern dewberry stem density 50 to 66% the season following treatment. Treatments that contained metsulfuron tended to provide some of the greatest levels of visual control and stem reduction. The spring following treatment, herbicide treatment did not influence forage grass yields compared to the untreated control; however, herbicide treatment reduced northern dewberry and other weed components of the total forage yield compared to the untreated control. These experiments indicate fall applications of herbicides that contain metsulfuron will reduce northern dewberry stem density by at least 50%, but that follow-up treatments will be necessary where severe infestations exist.