WSU Extension

Hortsense

Apricot
 
Disease
Bacterial canker 
Brown rot 
Cytospora canker 
Shothole (Coryneum blight) 
Silver leaf 
Insect
Brown marmorated stink bug 
Peach twig borer 
Peachtree borer 



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Caption: Coryneum blight symptoms: shothole, leaf spot, and fruit spot
Photo by: R.S. Byther
  
Apricot : Shothole (Coryneum blight)
(revision date: 4/11/2018)


Biology
Shothole is a fungal disease which attacks leaves, buds, blossoms, fruits, and twigs. Twig cankers are rare on apricot. On apricot, the fungus often infects and kills buds, which may be covered with a shiny, gummy material. Lesions on leaves and fruit are initially small purplish areas which expand into brown spots with light centers. The lesions are seldom larger than 1/4" in diameter. The infected spots on leaves often die and drop out in warm weather, giving leaves a "shothole" appearance. 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.
  • Space plantings and prune to provide good air circulation.
Select non-chemical management options as your first choice!

Chemical Management

Apply copper fungicides or chlorothalonil products at leaf drop in late fall before heavy rains. Apply IMMUNOX or chlorothalonil products 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 Liquid Copper Fungicide Conc/Organic Gardening
    Active ingredient: copper octanoate  |  EPA reg no: 67702-2-4
  • GardenTech Daconil Fungicide Conc
    Active ingredient: chlorothalonil  |  EPA reg no: 67572-82-71004
  • Monterey Liqui-Cop Copper Fungicidal Garden Spray
    Active ingredient: copper-ammonia complex  |  EPA reg no: 54705-7
  • Ortho Max Garden Disease Control Conc
    Active ingredient: chlorothalonil  |  EPA reg no: 239-2522
  • 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

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Caption: Coryneum blight symptoms: shothole, leaf spot, and fruit spot
Photo by: R.S. Byther
Caption: Coryneum blight gummy cankers
Photo by: R.S. Byther
Caption: Coryneum blight gummy canker
Photo by: R.S. Byther