Cause The fungus Nectria cinnabarina is considered a wound invader since it is frequently associated with pruning cuts. Naturally occurring scars may also be sites of entry for the spores. Broken fruit pedicels left in the tree during harvest are another site of entry. The fungus has a wide host range.
Symptoms Small, sunken cankers appear near wounds and develop slowly. After two or more seasons, small branches or twigs are girdled. Leaves beyond the canker generally wilt and die. Bright pink to coral-red fruiting bodies (sporodochia) break through the bark in the cankered area. Another fruiting body (perithecia) also will form in the same area. Both fruiting bodies are borne on a stroma.
Cultural control
- Pruning stubs should be relatively short.
- Remove and destroy all infected or dead wood.
- Instruct pickers not to leave fruit stems on the tree.
Chemical control Generally not needed and not recommended. Focus on cultural control tactics.
Reference Sutton, T.B., Aldwinkle, H.S., Agnello, A.M., and Walgenbach, J.F. 2014. Compendium of Apple and Pear Diseases and Pests, 2nd ed. St. Paul, MN: APS Press.