A preliminary assessment of high risk areas for Puccinia psidii (Eucalyptus rust) in the Neotropics and Australia

Puccinia psidii Winter, which causes both guava rust and eucalypt rust, is an important pathogen on eucalypts and other members of the Myrtaceae family in the Neotropics. If introduced into Australia it could represent a major potential threat to eucalypt plantations as well as native vegetation. Observations of the distribution of eucalypt rust epidemics in the Neotropics were analysed to develop a simple description of the species climatic requirements. Climatic mapping programs were used to generate maps showing high risk areas in the Neotropics and Australia. It is concluded that some northern parts of the Northern Territory as well as eastern coastal areas of northern New South Wales and Queensland are the regions most at risk to P. psidii in Australia. However, it is recognized that more detailed models and survey information are needed to provide better predictions of epidemic risks.