Economic impacts of Xylella fastidiosa on the Australian wine grape and wine-making industries

Overview \r\nXylella fastidiosa is a bacterium that affects many plant species. In Brazil X. fastidiosa infects an estimated 200 million citrus trees. In California, it causes over $100 million in yearly losses to the grape industry. And on the Italian peninsula of Salento, around one million olive trees are estimated to be infected. There is no cure for the disease. \r\n\r\n Recent outbreaks in Europe prompted Australia's biosecurity authorities to introduce emergency measures in late 2015 to reduce the risk of an incursion. As part of the heightened preparedness, the Department's Plant Biosecurity Division requested ABARES to assess the economic impacts of a potential X. fastidiosa outbreak on the wine grape and wine-making industries in Australia. \r\n\r\n ABARES assessed a range of scenarios and the expected benefits to the wine industry of keeping Australia free of X. fastidiosa and its vectors. Three scenarios of progressively smaller habitat suitability were assessed: \r\n• Scenario 1 - all existing wine grape growing areas \r\n• Scenario 2 - Scenario 1 areas with an average minimum winter temperature above 1.7 degrees C, and \r\n• Scenario 3 - Scenario 2 areas that were in close proximity to riparian vegetation. \r\n\r\n ABARES estimated that if it enters and establishes in Australia, X. fastidiosa could cost the Australian grape vine industries between $2.8 billion to $7.9 billion, over 50 years, on a net present value (NPV) basis. ABARES also found that if X. fastidiosa appears in a region but was contained within that region, the aggregate impact on the wine industry would be a fraction of the impact of an uncontrolled spread. Containing the outbreak to either the Murray Darling - Swan Hill or Lower Murray regions, for example, could avoid losses estimated between $2.6 billion and $2.0 billion, on a NPV basis. \r\n\r\nKey Issues \r\n• X. fastidiosa is not present in Australia, but is a major concern. \r\n• If it established in Australia, X. fastidiosa would pose a significant threat to the productivity, sustainability and competitiveness of Australia's wine industry. \r\n• Habitat suitability in Australia is likely to be high. \r\n• The current level of investment in prevention measures to reduce the risk of X. fastidiosa entering Australia appear to be highly cost-effective. \r\n• International experience suggests that successful eradication is unlikely. Nonetheless, were it to enter, enhancing early detection capacity would be prudent. \r\n\r\n