WSU Extension


Peach : Brown rot
(revision date: 1/22/2016)

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 the following spring.
Management Options

Non-Chemical Management
  • Rake and destroy infected debris and mummified fruit to reduce spread of disease. Remove mummified fruit remaining on the tree, as well.
  • Prune out infected twigs in late spring or 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 the moist conditions favoring disease.
  • Avoid overhead watering.
  • Control insects that cause wounds and provide infection sites for the fungus.
Select non-chemical management options as your first choice!

Chemical Management

Apply fungicides just before blossoms open. Additional applications at full bloom, and when most of the blossom petals have fallen. Sulfur gives only slight control and is not recommended for use during 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
  • Bonide Sulfur Plant Fungicide Micronized Spray or Dust RTU [Organic]
    Active ingredient: sulfur  |  EPA reg no: 4-62
  • Captan 50% WP Fruit & Ornamental
    Active ingredient: captan  |  EPA reg no: 4-459
  • 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
  • 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.
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Caption: Brown rot infected peach
Photo by: R.S. Byther
Caption: Brown rot blossom infection
Photo by: R.S. Byther
Caption: Brown rot stem cankers
Photo by: R.S. Byther
Caption: Brown rot mummified fruit
Photo by: R.S. Byther