Eucalyptus diseases in Uruguay

Eucalyptus plantations has reached ca. 1 million hectares in Uruguay, primarily planted for pulp and solid wood production. Several diseases are reported to Eucalyptus in Uruguay, with significant impact to the industry. The arrival of Teratosphaeria nubilosa, first detected in 2007, changed the focus of the species planted and the industry virtually abandoned Eucalyptus globulus due to the significant effect of this disease on growth, survival and therefore wood yield. Years later, in 2011, the arrival of Teratosphaeria pseudoeucalypti caused similar effect on E. camaldulensis and E. tereticornis. This disease may cause severe defoliation even in adult trees, resulting in tree death. Since these Eucalyptus species are primarily used for firewood, livestock shelter and shade, and urban parks, this pathogen had a significant effect not only economic but social. Both exotic pathogens are clear examples of devastating effects of aggressive pathogens arriving to a new area with predominance of susceptible hosts. In addition, other diseases are affecting wood production. For instance, Ceratocystis wilt is of significance for solid wood production in the northeastern region. The increase of E. dunnii area has raised bacterial problems, such as bacterial blight caused by Erwinia psidii. Eucalyptus rust and bacterial leaf spot are also of high relevance on E. grandis countrywide, but primarily in the northeastern region. The initiative of replacing E. globulus by E. smithii has faced several problems associated primarily with site adaption. Additionally, the biological interaction of Eucalyptus plantation with native Myrtaceous trees has also been studied evidencing a strong biological exchange where exotic pathogens have been reported on native trees and native pathogens on Eucalyptus plantations. This movement is far more common than has been previously thought and should be carefully monitored.