A severe canker disease of Corymbia ficifolia caused by Quambalaria coyrecup in native and urban forests of Western Australia

A serious canker disease is affecting the health of Corymbia ficifolia in urban areas of Perth, Western Australia. Quambalaria coyrecup was frequently associated with diseased trees and its presence confirmed by morphological characters and DNA sequencing. A number of Quambalaria species have previously been identified as causal agents of canker and shoot blight diseases on a range of Eucalyptus and Corymbia species. It was therefore the aim, using glasshouse studies, to determine whether Q. coyrecup was the primary causal agent of the cankers on C. ficifolia and whether other Quambalaria species could also be associated with the disease. All seedlings inoculated with Q. coyrecup produced canker symptoms within 1 month after inoculation. Canker lesions typical of those observed in the field also occurred in the four subsequent months, after which time the trial was terminated. Inoculation with Q. cyanescens and Q. pitereka (isolated from C. ficifolia shoots) did not result in lesion development. This study establishes that Q. coyrecup is a serious pathogen of C. ficifolia and that wounding is required for canker development to occur. The management of Quambalaria canker must therefore include the minimization of artificial wounding of trees in the nursery and field.