Black Canker (Target Canker)
Ceratocystis fimbriata (black canker); Cytospora notastroma (target canker)
11 host plants · Fungal
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Concentric rings create a target pattern on cankers. Prune affected branches and sterilize tools. The pathogen (Ceratocystis fimbriata (black canker); Cytospora notastroma (target canker)) favors moist conditions and enters through wounds or natural openings. You are most likely to see symptoms during the growing season when conditions shift between wet and warm. On susceptible hosts, the damage can progress quickly if left unchecked.
Prune out cankered branches at least six inches below visible symptoms, making cuts into healthy wood. Sterilize your tools between cuts. Canker pathogens typically enter through wounds, so minimize pruning injuries and avoid working on trees when bark is wet. Maintain tree vigor through proper watering and avoid stress from drought or compacted soil, which makes trees more susceptible.
Quick Reference
Management
Peak infection Oct–May during cool, wet conditions. Canker development and death of branches rapid (weeks to months). Symptoms visible winter/spring. BBCH 97–09.
Wounding of trees (logging, storm damage, pruning); beetle/fly vector presence; stressed trees more susceptible; mature/old-growth stands more frequently affected
Cultural Controls
- Remove dead branches, cutting well below (at least 1 ft) any visible discoloration in the bark. Do not establish new orchards close to or downwind from badly diseased orchards. Treetop or other hedgerow pruning and overhead irrigation are not advised where the disease is a problem. Take special care to avoid wounding trees during the growing season. Tractors and sprayers commonly inflict such woun