EUCALYPTUS RUST - A DISEASE WITH THE POTENTIAL FOR SERIOUS INTERNATIONAL IMPLICATIONS

Eucalyptus spp. are propagated extensively as non-natives in plantatio ns in many parts of the tropics and sub-tropics. A number of diseases result in serious losses to this economically important forest resourc e. Eucalyptus rust, caused by Puccinia psidii, is one such example. Th e economic losses due to this disease are the result of infections of seedlings, young trees, and coppice. P. psidii occurs predominately in Central and South America, but reports of a similar rust are known fr om other areas. Eucalyptus rust is a remarkable disease in that the pa thogen is not known on eucalypts in their centers of origin. It has ap parently originated on native Myrtaceae in South America and is highly infective on some Eucalyptus spp. planted there. P. psidii causes one of the most serious forestry diseases in Brazil and is considered to be the most serious threat to eucalypt plantations worldwide. Advances in eucalyptus rust research are reviewed here, with a focus on topics such as distribution, host range, pathogen specialization, symptomato logy, etiology, epidemiology, and control.