Suppression of vulpia and goose grass in dryland pastures through the choice of sown pasture species

Abstract

Vulpia (Vulpia myuros) and goose grass (Bromus hordeaceus) are common annual grass weeds throughout New Zealand in dryland pastures. They compete with sown species, suppressing pasture production and livestock performance. Their seeds may also damage hides and carcasses. Choice of sown pasture species can be important in limiting their spread. The abundance and fecundity of sown vulpia and goose grass was measured over 1 year in dryland Canterbury pastures sown with different grass and legume species. Survival and seedhead production of both vulpia and goose grass were lower in pastures oversown with the annual legumes subterranean and balansa clover. Annual grass weed establishment was also lower in cocksfoot than perennial ryegrass pastures. In Canterbury dryland pastures subject to summer drought, cocksfoot-based pastures oversown with subterranean and balansa clover show promise as a better alternative to ryegrass-based pastures for suppressing the ingress of these species. Repeating this study over several years in different environments would determine how widely these conclusions can be applied.