WSU Extension

Hortsense

Peach : Crown gall
(revision date: 5/20/2014)


Biology
Crown gall is caused by a soilborne bacterium. The bacteria infect through wounds on the crown and roots. Young galls are fleshy, white, enlarged masses on the roots or stems. Older galls are hardened and turn dark brown and woody or corky in appearance. They range in size from less than an inch to several inches across. The bacteria can be spread from contaminated to clean soil by water movement. Damage varies with location and size of galls. Small galls are essentially harmless. Large galls on the crown may weaken or girdle trees. The growths can also be an aesthetic concern.
Management Options

Non-Chemical Management
  • Plant disease-free materials.
  • Remove and destroy declining trees with large crown galls. Also remove roots and surrounding soil where possible.
  • Prune out galls when practical. Sterilize pruning tools between cuts to avoid spreading bacteria to healthy tissue.
  • Avoid injuries to the bark, crown, and roots while planting.
  • Do not replant susceptible species in contaminated soil.
Select non-chemical management options as your first choice!

Chemical Management

None recommended

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Caption: Crown gall
Photo by: R.S. Byther