Ornamental Plum: Shothole (Coryneum blight)
categories: Ornamental Plum Ornamental Plum Diseases Ornamental trees Ornamentals
last review date: 2025-06-29 10:37
Photo by: R.S. Byther
Biology
Coryneum blight is a fungal disease.
Lesions on leaves are initially small, purplish, round to oval areas which expand into brown spots with light centers. The lesions are typically up to 1/4″ in diameter.
The infected spots on leaves often die and drop out in warm weather, giving leaves the characteristic “shothole” appearance of the disease.
The fungus probably overwinters on the bark and in infected buds. Spores are easily spread by water.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Avoid overhead watering.
- Prune and destroy dead buds and cankered twigs if present.
- Rake and destroy infected leaves.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- If fungicides are used as part of your management program, apply at 50% leaf fall in late autumn before heavy rains to protect leaf scars (except sulfur products).
- Chlorothalonil or sulfur products can also be applied in spring when petals fall.
- NOTE: Bonide Fung-onil is for spring use only.
- Homeowners should not make foliar applications to trees over 10 ft tall.
- Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.
Approved Pesticides
Examples of pesticides that are legal for home use in Washington State are listed below.
The list may not include all products registered for this use.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.