POTENTIAL IMPACT OF CLIMATE-CHANGE ON PLANT-DISEASES OF ECONOMIC-SIGNIFICANCE TO AUSTRALIA

Burning of fossil fuel, large scale clearing of forests and other huma n activities have changed global climate. Atmospheric concentration of radiatively active CO2, methane, nitrous oxide and chlorofluorocarbon s has increased to cause global warming. In Australia temperature is p rojected to rise between 1 and 3 degrees C by 2100. This review is the result of a recent workshop on the potential impact of climate change on plant diseases of economic significance to Australia. It gives an overview of projected changes in Australian climate and the current st ate of knowledge on the effect of climate change on plant diseases. Ba sed on an assessment of important diseases of wheat and other cereals, sugarcane, deciduous fruits, grapevine, vegetables and forestry speci es, climate change in Australia may reduce, increase or have no effect on some diseases. Impacts will be felt in altered geographical distri bution and crop loss due to changes in the physiology of host-pathogen interaction. Changes will occur in the type, amount and relative impo rtance of pathogens and diseases. Host resistance may be overcome more rapidly due to accelerated pathogen evolution from increased fecundit y at high CO2 and/or enhanced UV-B radiation. However, uncertainties a bout climate change predictions and the paucity of knowledge limit our ability to predict potential impacts on plant diseases. Both experime ntal and modelling approaches are available for impact assessment rese arch. As the development and implementation of mitigation strategies t ake a long time, more research is urgently needed and we hope this rev iew will stimulate interest.