Weeds of pastures and field crops in Tasmania : economic impacts and biological control

It has been estimated that weeds cost Australian agriculture about $4 billion annually (Sinden et al 2004), In Tasmania, about 1.8 million ha is used for production agriculture (Australian Bureau of Statistics 2001). In 1996, the cost of weeds to Tasmanian primary producers in terms of lost production and the cost of control was estimated at $33 million annually (Anon 1996). The primary aim of this technical bulletin is to provide a revised assessment of the cost of weeds to Tasmanian pastures and field crops as well as identifying the weeds that are having the most significant impact on Tasmanian agriculture. It also reviews the current status of all weed biological control programs that have been conducted in Tasmania against some of the major weeds and provides a case study of the successful biological control program on ragwort. The document should serve as a useful reference for those involved in weed control both within the state and nationally.