Seventeenth Australasian Weeds Conference

phorus L.) is an annual broadleaf invasive weed from the Asteraceae family. It is a threat to the pasture lands of central Queensland and has the potential to convert much traditional pasture land into parthenium-dominated communities. This study was initiated to identify beneficial pasture plants that may be able to competitively displace parthenium weed from the pres-ently infested areas. Initial trials were undertaken in the glasshouse to select plants to be further tested at two parthenium-infested field sites in central Queensland. In the glasshouse an addition series competition trial, in several steps, was run with 20 selected grasses and legume species. Ten species were selected and were further tested in the field under natural conditions. Purple pigeon grass, guinea grass, buffel grass, Indian bluegrass, bull Mitchell grass, Kangaroo grass, pitted bluegrass and hoop Mitchell grass were all ranked as strong displacement plants in the glasshouse trial. In the field purple pigeon grass, buffel grass, butterfly pea, Kangaroo grass and bull Mitchell grass were all determined to be useful at displacing parthenium weed at the Injune site, while Rhodes grass, buffel grass, Queensland bluegrass and butterfly pea were all shown to do the same at the Monto site. These find-ings indicate that selected pasture species are likely to be a useful part of an integrated management plan for parthenium weed in the infested regions of central Queensland