Flupropanate <i>in vitro</i> pasture species susceptibilities

Abstract

Flupropanate a soilactive herbicide that inhibits lipid biosynthesis has become available in New Zealand for the selective control of the stipoid grasses Nassella neesiana and N trichotoma in pasture In commercial spray operations and field trials the selectivity of the herbicide has been extremely variable As a first step towards identifying pasture species that could be safely sown following application of the herbicide the in vitro doseresponse of 33 species and cultivars (grasses and dicotyledons) was determined Ranking the cultivars based on the slopes of linear regressions fitted to their radicle lengths (relative to untreated control) against the logarithm of flupropanate dose suggested that ryegrass and Nassella spp are among the most sensitive whilst plantain chicory and some legumes including lucerne are relatively tolerant The rankings from this study will be subjected to validation in a field trial using a subset of the species