Evaluation of Clopyralid and Additives for Coronilla varia Suppression in a Remnant Prairie (Wisconsin)

摘要

Coronilla varia (crown vetch) is a perennial legume that has been extensively planted for erosion control along roadsides since the 1950s, and has become a widespread invasive species in grasslands throughout the Midwestern United States. Coronilla varia spreads through prolific seed production and several modes of vegetative expansion, including rhizomes, crown buds, and root-splitting (Klime?ová and de Bello 2009, Losure et al. 2009). Once established, C. varia outcompetes and displaces native vegetation through shading and smothering (Tu 2003). Coronilla varia invasions have been directly linked to declines in at-risk plant species populations (Walck et al. 1999), decreased reproductive success in prairie plants (Molano-Flores 2014), and indirect reductions in insect pollinator diversity through loss of plant diversity (Hopwood 2008). Suppression of C. varia is a management priority in regions where it is problematic, yet only a limited number of studies are available to direct practitioners efforts. We conducted complementary anatomical and field studies to develop an effective and cost-feasible method for reversing C. varia invasions in grassland communities. We first quantified C. varia's capacity for clonal expansion and examined aspects of its cellular anatomy relevant to the use of herbicides for suppression. Then, using our anatomical findings to refine our approach, we tested the effects of clopyralid (Transline~?, Dow Agro-Sciences, Inc.) herbicide on C. varia in a four-year field experiment.