Canadian Forest Service Publications
Spatio-temporal severity patterns and association of certain key factors with butternut canker severity in Quebec. 2018. Sambaraju, K.; DesRochers, P.; Rioux, D. In Proceedings of the 77th Annual Meeting of the Northeastern Division of the American Phytopathological Society, November 1-3, 2017, Quebec City, Canada.
Available from: Laurentian Forestry Centre
Catalog ID: 39079
CFS Availability: Not available through the CFS (click for more information).
Butternut is an indigenous tree species important from a conservation and biodiversity perspective in the mixed hardwood forests of eastern North America. An exotic fungal pathogen, Ophiognomonia clavigignenti-juglandacearum (Oc-j), causes butternut canker that is characterized by dieback and trunk cankers that eventually kill the tree. This disease currently endangers the survival of butternut throughout its natural habitat in Canada and the United States. We studied the distribution patterns of butternut canker in Quebec using data collected from 24 locations and assessed the relationships of tree location and topography with trunk canker and dieback. We also assessed the temporal changes in severity of trunk canker and dieback on a small sample of trees from three locations. Butternut canker was found in all study locations in Quebec. Trunk canker showed a southwest to northeast declining trend in severity while dieback was more related to the altitude. Generalized mixed models showed a negative association of trunk canker with increasing latitude. Dieback showed a positive relationship with elevation. Trees on flat lands showed a greater probability of trunk canker than those on higher slopes, whereas dieback was unrelated to slope. Trunk canker and dieback worsened over time on individual trees. Given the spread of the disease and the strong future likelihood of extirpation of butternut by Oc-j, strategies to restore this tree species should be a high priority.