Bird vetch is a perennial Eurasian plant which, unlike many exotic weed species, can invade low fertility areas that have not been disturbed. It also is common in pastures, woodland, and tall forb communities. Bird vetch is expanding along Alaskan roadsides, in urbanized areas, and in low density forests. A greenhouse study was conducted to determine efficacy of six herbicide treatments applied at reduced rates in 2005 and again in 2006 for bird vetch seedling control. Bird vetch seedlings were tolerant of reduced rates of chlorsulfuron and 2,4-DB; however, complete control was achieved with rates of clopyralid, dicamba plus diflufenzopyr, triclopyr, and 2,4-D that were a fourth to an eighth of the full registered rate. These results will be important for developing effective, low-cost methods for controlling bird vetch in Alaska, especially on the outer margins of infestations.
Nomenclature: Chlorsulfuron, clopyralid, dicamba, diflufenzopyr, triclopyr, 2,4-D, 2,4-DB, bird vetch, Vicia cracca L. VICCR