Agriculture, Aquaculture and Fisheries - Evaluation of Herbicide Applications Following Forage Harvest to Control Smooth Bedstraw

Abstract: Smooth bedstraw (Galium mollugo) is becoming a serious weed in pastures, hayfields and field margins across the Maritime region. It is typically found in acidic, low fertility areas but is moving into intensively managed areas. A trial was initiated near Bathurst, New Brunswick to evaluate herbicide control options, with application made two weeks after forage harvest. All rates of triclopyr and aminopyralid tested offered consistent control of smooth bedstraw in the season of application and into the season following application. The addition of 2,4–D amine to aminopyralid did not improve control. MCPA amine, mecoprop/MCPA/dicamba, 2,4–D amine and carfentrazone–ethyl demonstrated early activity on the weed but the effect dissipated in further evaluations. Triclopyr and aminopyralid significantly improved grass species ground cover in the year following application. The cost and control of aminopyralid and triclopyr should be evaluated further in the Maritimes, especially in comparison to glyphosate application followed by fertility and re–seeding treatments.