Fungal Cankers

You see branch dieback and sunken cankers on cherry or plum, with flag shoots where stem infections girdle limbs. Cytospora and other fungal cankers follow sunscald or winter injury on stressed trees. Prune out dead wood well below visible disease, avoid season-end wounding, and manage irrigation and fertilization for steady, not excessive, growth.

Remove dead branches, cutting well below (at least 1 ft) any visible discoloration in the bark. Infected material should be removed from the orchard and destroyed if possible.