WSU Extension


Bacterial leaf spot and dieback 
Leaf scorch 
Nectria canker 
Phyllosticta leaf spot 
Powdery mildew 
Tar spots 
Verticillium wilt 
Cottony maple scale 
Maple bladdergall mite 

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Caption: Tubercularia canker fruiting bodies
Photo by: R.S. Byther
Maple : Nectria canker
(revision date: 4/28/2014)

Nectria is a fungal infection which often attacks via wounds and forms cankers on twigs, branches, and trunks. The cankers are often sunken areas that develop conspicuous yellow to orange-red fungal fruiting bodies in the dead bark. Nectria cankers may girdle twigs and kill them or become elongated and enlarge year after year. Older cankers may develop a characteristic target or bull's-eye shape. Infected branches are susceptible to breakage in wind storms and should be removed.
Management Options

Non-Chemical Management
  • Provide proper culture to maintain healthy, vigorous, disease-resistant trees.
  • Avoid wounding trees.
  • Prune and destroy infected twigs and branches.
  • Prune properly to reduce risk of infection through pruning wounds or stubs.
  • To minimize infection risks, do not plant in cold pockets or on poorly drained sites.
Select non-chemical management options as your first choice!

Chemical Management

None recommended


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Caption: Tubercularia canker fruiting bodies
Photo by: R.S. Byther