Perennial Canker (Bull's-eye Rot)
Cryptosporiopsis perennans
18 host plants
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Unlike anthracnose cankers that grow one season then stop expanding, these cankers enlarge year after year, gradually girdling limbs and causing eventual death. Cankers are very difficult to remove once established due to their persistent expanding nature. Prune well below visible symptoms and destroy all infected material promptly to prevent spread.
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 (April-May) for new canker development and expansion on stems.
Fall and spring; cool wet conditions. Fall (August-October): rain spreads spores to fruit and shoots. Spring: wet conditions favor canker expansion.
Cultural Controls
- Prune out cankers when practical.
- Harvest apples at the proper stage of maturity.
- Keep fruit dry after picking and remove from orchard as soon as possible.
- Avoid wounding trees.
- If wounds occur, induce rapid healing.
- Prevent sunscald or southwest injury using white wash of trunks or shields.