Canker
Nectria spp., Cytospora spp., Botryosphaeria spp., Diaporthe spp., Phomopsis spp.
Overview
A general term for localized dead areas on bark of woody plants caused by various fungi and bacteria. Cankers may girdle branches or trunks, causing dieback above the infection point.
Symptoms
Sunken, discolored, dead areas on bark. Cracked or peeling bark around lesion margins. Gumming or resin exudation. Branch dieback above cankers. Fruiting bodies may be visible on canker surfaces.
Environmental Conditions
Variable
Prevention
Maintain tree vigor through proper watering and nutrition. Avoid wounding bark. Prune during dry weather. Paint large pruning wounds. Plant adapted species for the site.
Management
Prune out cankered branches well below the canker margin. Sterilize pruning tools. Improve tree vigor. Copper sprays may prevent new infections. Remove severely infected trees.