WSU Extension

Hortsense

Crabapple
 
Disease
Powdery mildew 
Scab 
Stem rot 
Insect
Aphids 
Apple-and-thorn skeletonizer 
Leafrollers and leaftiers 
San Jose scale 
Spider mites 



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Caption: Crabapple stem rot: rotten stem has a dark blotch
Photo by: R.P. Regan
  
Crabapple : Stem rot
(revision date: 4/28/2014)


Biology
Stem rot of crabapple is caused by a soil-borne fungus. This disease is most prevalent in the winter on nursery stock. The fungus infects through wounds on the stem where the bark is broken. Cankers develop on the stems of young plants and near the base of older plants. Active cankers are orange to purple-brown with a darker margin. Older cankers are brown, slightly sunken, and may develop cracks. The tissues beneath the canker may be discolored. Twigs and branches above the canker may show yellowing leaves or die back. Cankers can grow to 8" in length and may expand to completely girdle the stem.
Management Options


Non-Chemical Management
  • Plant disease-free plant material.
  • Prevent injury to the stems and trunks of trees.
  • Plant in well-drained sites.
  • Do not mound soil around trunks.
  • Do not plant in infected areas.
Select non-chemical management options as your first choice!

Chemical Management

None recommended

Images

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Caption: Crabapple stem rot: rotten stem has a dark blotch
Photo by: R.P. Regan