Anthracnose (Bull's-eye Rot)
Cryptosporiopsis curvispora
16 host plants
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Watch for reddish-brown cankers that form on small branches and expand over one growing season, girding twigs especially during wet springs. As the canker expands, surrounding healthy tissue reacts with a characteristic crack forming at the margin. Later you'll see bull's-eye rot on stored fruit, brown sunken spots with concentric rings and spore masses in the center. Prune infected branches well before fall rains, which spread spores from old cankers to developing fruit. Use certified disease-free stock and scout regularly for early canker detection.
Reduce moisture around affected tissue by improving drainage and air circulation. Remove rotted material cleanly and dispose of it away from the planting area. Avoid wounding healthy tissue during cleanup, as fresh wounds create new entry points. If the problem keeps returning, evaluate whether the site is too wet or poorly drained for the species you are growing.
Quick Reference
Management
Fall (August-October) for fruit infection; spring (March-May) for canker development and shoot infection. Peak fall vulnerability: 8 weeks pre-harvest.
Fall: cool wet conditions (50-60°F) with rain; 8 weeks pre-harvest peak fruit vulnerability. Spring: wet conditions during canker development and sporulation.
Cultural Controls
- Aggressive scouting for and removal of cankers is the key to long term control.
- Whole tree removal is recommended in British Columbia nurseries when cankers are found.
- Establish new plantings with clean stock free of visible cankers.
- Locate new orchards as far as possible from older orchards that may have existing cankers.
- Scout new orchards for the disease, because early detection will aid in overall control.
- Prune out and burn affected twigs and branches, especially on highly susceptible cultivars.
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