Management of Spreading Dogbane (Apocynum androsaemifolium) in Wild Blueberry Fields

Abstract

Spreading dogbane is a troublesome weed of wild blueberry fields. Field studies were conducted in 2008 and 2009 to evaluate efficacy of different herbicides and application techniques on spreading dogbane as well as blueberry tolerance. Results indicated that summer-broadcast nicosulfuron at 25 g ai ha−1with 0.5% v/v blend of surfactant with petroleum hydrocarbons suppressed (> 60%) spreading dogbane at three of four sites. Spot sprays with dicamba at 1 kg ae ha−1effectively controlled (> 80%) spreading dogbane with minimal (19 to 23%) blueberry damage at three of four sites. Glyphosate spot sprays at 5 g ae L−1water provided more effective and longer control than hand pulling. Wiping with glyphosate at 154 g ae L−1water or wiping triclopyr at 29 g ae L−1water onto the shoots is also an effective control method for localized patches of spreading dogbane. Although low to moderate crop damage may accompany these techniques, it may still be tolerable for growers to apply these options to limit long-term yield loss caused by spreading dogbane.