Control of African lovegrass by flupropanate in a flora conservation context

Context Managing widespread invasive plants to support biodiversity conservation is a significant challenge that requires weed control methods that have lesser impacts on co-occurring native species than ongoing weed invasion. African lovegrass (Eragrostis curvula) is a perennial grass invasive in many regions globally. There is a lack of effective control options, particularly in diverse native vegetation where application of broad-spectrum herbicide has risks of unacceptable off-target impacts. Aims We tested the effectiveness of flupropanate (sodium 2,2,3,3-tetra-fluoropropionate) in controlling African lovegrass in a conservation context in Mediterranean-climate south-western Australia, testing two application rates and measuring target and off-target impact. Methods Cover and condition (alive or dead) of plant species were measured in replicate plots in a ‘before-after-control-impact’ design. A small sample of endangered Grevillea curviloba individuals was deliberately treated with flupropanate. Key results Flupropanate significantly reduced African lovegrass cover, with greater reduction at the higher application rate. No significant off-target effects could be detected at a community or plant functional group level nor in the deliberate exposure of G. curviloba. Conclusions The results of this study indicate that flupropanate is effective in controlling African lovegrass in conservation settings in south-western Australia, including where G. curviloba is present. These findings contribute to the growing body of knowledge on the use of flupropanate for invasive grass management. Implications Possible off-target impacts on a single species in this study, and stronger evidence from other sources, suggest that robust testing of the susceptibility of conservation-listed flora to flupropanate should precede application in the habitat of these species.