Pathogenicity of seven species of the Botryosphaeriaceae on Eucalyptus clones in Venezuela

The Botryosphaeriaceae include several well recognised Eucalyptus pathogens of which various species have recently been found on Eucalyptus spp. in Venezuela. An initial inoculation trial was conducted using seven species (Botryosphaeria mamane, B. dothidea, Lasiodiplodia theobromae, Neofusicoccum andinum, N. parvum, N. ribis and Pseudofusicoccum stromaticum) on one commercially propagated clone representing a Eucalyptus urophylla x E. grandis hybrid in Venezuela. Stems were inoculated and lesion development recorded after 7 weeks. Inoculations with B. mamane, B. dothidea, L. theobromae, N. andinum and P. stromaticum showed little effect, but N. parvum and N. ribis caused bark swelling around the inoculation points with kino exudation. A second inoculation trial was performed on four commercial clones to evaluate variation in their tolerance to infection by N. ribis and N. parvum, which were the most pathogenic in the first trial. The clones differed significantly in their tolerance to infection by N. parvum and N. ribis, and N. parvum was significantly more virulent than N. ribis on all clones. These results illustrate the potential of using Eucalyptus clones to manage canker disease of Eucalyptus caused by species of Botryosphaeriaceae.