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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Birch > Unusually colored area on branch/trunk

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Birch > Trunk/Branches > Unusually colored area on branch/trunk

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Leaf and shoot blight
Diaporthe alleghaniensis

  • Black sunken cankers occur on bark of infected branches
  • Infections on young shoots cause branch tips to curl over in the form of a Shepard's crook
  • Leaves wilt, die and remain attached to the branch when the canker completely girdles the branch
  • Occurs only on yellow birch
  • More information on Leaf and shoot blight
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  • Image: Coral spot canker 1
  • Image: Coral spot canker 2
  • Image: Coral spot canker 3

Coral spot canker
Nectria cinnabarina

  • Raised cushion-like bumps on affected branches, may be cream
    to orange or red, turn black with age
  • Sunken dark brown area on branch that is often cracked or has a ridge at the edge
  • Dead branches and twigs are often first observed in early spring
  • Common on trees stressed by drought, recent transplant or
    other factors
  • More information on canker
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  • Image: Perennial nectria canker 1
  • Image: Perennial nectria canker 2
  • Image: Perennial nectria canker 3

Perennial nectria canker
Neonectria galligena

  • Red to reddish orange raised cushion like bumps can occasionally be seen on the edge of the canker
  • Cankers do not have bark and raised ridges of wood occur in target-like rings within the canker
  • Sunken target shaped cankers on main trunk or branches
  • Dead branches and twigs killed by girdling cankers
  • More information on Perennial nectria canker

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