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Caption: White pine blister rust
Photo by: R.S. Byther
  
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Pine : White pine blister rust
(revision date: 4/23/2014)


Biology
White pine blister rust is a fungal disease which attacks all five-needle or white pines. Elongate cankers are formed on trunks and branches. The cankers may ooze resin. In the spring, fungal spores are formed in orange- or rust-colored pustules or blisters on the bark of the cankers. Branches usually die back (flagging) above the canker, which may also have severe pitching associated with it. The alternate hosts for white pine blister rust are currants and gooseberries, which display brown, hairlike structures and tiny yellow blisters on the underside of infected leaves. The upper surface of currant leaves is often discolored. Infection of pines typically occurs in late summer.
Management Options

Non-Chemical Management
  • Plant resistant species. Only five-needle (white) pines are affected.
  • Remove severely infected trees.
  • Prune infected branches, making pruning cuts well below diseased tissues.
  • Do not plant in sites with poor air circulation, as moist conditions favor disease.
  • Do not plant white pines near currant or gooseberry patches. If necessary, remove alternate hosts near pine plantings.
Select non-chemical management options as your first choice!

Chemical Management


None recommended

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Caption: White pine blister rust
Photo by: R.S. Byther
Caption: White pine blister rust trunk canker
Photo by: R.S. Byther
Caption: White pine blister rust alternate host
Photo by: R.S. Byther