TROPICAL WEEDS

Weeds are threatening and destroying vast areas of the tropics throughout the world and controlling them is expensive. One example is the effort put into trying to keep one weed, mimosa, out of Kakadu. It costs half a million dollars a year.

The Tropical Weeds group is mainly based in Brisbane in Queensland, with a small group in Darwin in the Northern Territory. Their research involves finding natural enemies of target weeds in their home ranges, assessing their safety and efficacy in quarantine, releasing them where they are needed and evaluating their impact. The research covers a range of wetland, aquatic and rangeland weeds in northern Australia. It also looks at integrating biological control with other control methods.

Their target weeds are mimosa (Mimosa pigra), cabomba (Cabomba caroliniana), alligator weed (Alternanthera philoxeroides), parkinsonia (Parkinsonia aculeata), bellyache bush (Jatropha gossypiifolia), mesquite (Prosopis sp.) and an analysis of the risk of tropical grasses becoming weeds. They are also investigating the non target impact in biological control of Australian weeds and using ecological modelling to improve weed management.

Staff from the United States Department of Agriculture (USDA) are also housed in the Brisbane laboratories where they work on biological control of a range of Australian native plants that have become weeds in the USA.