Feasibility of biological control of solanaceous weeds of temperate Australia

Summary

The solanaceous weeds, prairie ground cherry (PGC) and silverleaf nightshade (SLN) have been listed as Priority Weeds for the grazing industries of Australia (Weeds of Significance to the Grazing Industries of Australia 2003). They have extensive and deep perennial root systems, are hardy, withstand drought, shading and trampling and are toxic to stock. They are problem weeds in both the cropping/pasture and perennial pasture zones of temperate Australia. Due to their widespread distribution and difficulty and expense of control by other methods, biological control is considered a high priority research and development need for these weeds. 
The purpose of this project was to determine the need for and feasibility of initiating classical biological control programs for PGC and SLN in Australia. This were achieved by addressing 3 main issues: 
1) By understanding the distribution and ecology of these weeds, the current impact of PGC and SLN to Australian agriculture and how biological control would benefit agricultural industries should a program be initiated in the near future. 
2) By reviewing what we know about the management of these weeds, where there are deficiencies in the control technologies available, our knowledge of how better to control them and future research needs. 
3) By compiling and analysing information on organisms found to be associated with PCG and SLN, reviewing the success of biological control programs against these weeds elsewhere and the possibilities for biological control in Australia.
The information sourced for this project was gathered from a range of sources including literature reviews, unpublished data from researchers and farmer surveys, notes and outcomes from workshops and anecdotal information from extension professionals and farmers. The project also collaborated with the Weeds CRC, universities and other agencies conducting research of relevance to solanaceous weeds in Australia and overseas, to ensure all information sources and expertise are accessed and utilised. The final outcome of the project was a review of the evidence which may contribute to developing a case for MLA to invest in research for bio-control of PGC and SLN, develop recommendations on the role and potential of biological control. This includes an outline of what was involved in a biological control project, the duration and the potential costs.