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

Non-Chemical Management

Prune and destroy dead buds and cankered twigs if present.
Rake and destroy infected leaves.
Avoid overhead watering.

Select non-chemical management options as your first choice!

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, IMMUNOX, 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.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

Bonide Fung-onil Multi-Purpose Fungicide Conc
Active ingredient: chlorothalonil | EPA reg no: 60063-9-4
Bonide Sulfur Plant Fungicide Micronized Spray or Dust RTU [Organic]
Active ingredient: sulfur | EPA reg no: 4-62
GardenTech Daconil Fungicide Conc
Active ingredient: chlorothalonil | EPA reg no: 67572-82-71004
Hi-Yield Snake Eyes Dusting Wettable Sulfur
Active ingredient: sulfur | EPA reg no: 7401-188-34911
Lilly Miller Sulfur Dust Fungicide/Insecticide Dust or Spray
Active ingredient: sulfur | EPA reg no: 802-16
Ortho Max Garden Disease Control Conc
Active ingredient: chlorothalonil | EPA reg no: 239-2522
Soap-Shield Flowable Liquid Copper Fungicide [Organic]
Active ingredient: copper octanoate | EPA reg no: 67702-2-56872
Spectracide IMMUNOX Multi-Purpose Fungicide Spray Conc
Active ingredient: myclobutanil | EPA reg no: 9688-123-8845
This list may not include all products registered for this use.

Images

+ Show larger images


Caption: Coryneum blight symptoms on leaves and fruit Photo by: R.S. Byther

WSU Extension

Hortsense