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: Brown rot on apricot fruit
Photo by: R.S. Byther
  
Apricot : Brown rot
(revision date: 1/22/2016)


Biology
Brown rot is a blossom-infecting fungal disease. Infected flowers wilt and die. The brown blossoms remain attached to the twigs, becoming covered with a grayish-brown fungal growth during wet weather. Blossom or fruit infections may spread to twigs. Infected twigs develop sunken, elongate cankers with gumming at the margins. Leaves on girdled shoots turn brown and remain attached. Infected fruit initially show a small brown spot which rapidly enlarges. The fruit remains fairly firm and often becomes covered with gray-brown fungus. Fruit may dry and harden into mummies, which serve as a source of infection in the spring.
Management Options


Non-Chemical Management
  • Remove mummified fruit in the tree or under the tree to reduce spread of disease.
  • Prune out infected twigs during summer. Do not wait until the dormant season, when infected twigs are difficult to distinguish.
  • Space plantings and prune to provide good air circulation. This will reduce moist conditions which favor disease development.
  • Avoid overhead watering.
Select non-chemical management options as your first choice!

Chemical Management

Apply fungicides just before blossoms open and at full bloom. 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 Infuse Systemic Disease Control
    Active ingredient: propiconazole  |  EPA reg no: 100-773-4
  • GardenTech Daconil Fungicide Conc
    Active ingredient: chlorothalonil  |  EPA reg no: 67572-82-71004
  • 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: Brown rot on apricot fruit
Photo by: R.S. Byther
Caption: Brown rot canker
Photo by: R.S. Byther