See:
Pine, White - White Pine Blister Rust
Cause Atropellis pinicola, a fungus reported to be common in Washington on Lodgepole and Western white pine. Has been reported from all states. Trees of all sizes and ages are affected. Ascospores are windblown in summer or early fall during rainy weather. The spores can penetrate undamaged bark in the axil of branches or twigs.
Lachnellula pini (formerly Dasyscyphus pini) a fungus reported to be common in Washington on Western white pine. The disease is most prevalent at high elevations, but is also encountered on poor sires at lower elevations.
Symptoms
Atropellis canker - cankers occur on the limbs of young trees, but seldom on the main trunk. The needles on branches girdled by the cankers die and are easily seen from a distance. The cankers are smooth, elongated, and flattened depressions, which remain covered by the bark. The wood under the canker is bluish black. The black fruiting bodies (apothecia) on the bark are very small, rarely measuring more than 0.125 inch in diameter, and usually have a short central stalk. Most cankers are found on trees up to 40 ft high. Lodgepole pine may have copious resin flow from the cankers. Young seedlings are frequently killed by girdling cankers. Possible to confuse with rust diseases.
Dasyscyphus canker - The perennial cankers are swollen and flat faced and the bark over the canker is roughened and cracked. Excessive resin flow is often associated with the cankers. They are usually found on the smaller branches which they eventually girdle. On larger branches the cankers persist, but do not girdle the branch. The cup-shaped fruiting bodies (apothecia) present on the face of the cankers measure up to 0.25 inch in diameter and have a short stalk. The inner surface of the cup is bright orange, while the outside is brown and hairy.
Cultural control
- Prune out and destroy infected branches.
- Remove infected seedlings from the nursery.
- Forest trees-thinning stands is helpful.
Chemical control Unknown.
Reference Shaw, C.G., and Harris, M.R. 1960. Important diseases and decays of trees native to Washington. Ag Extension Service, WSU. Extension Bulletin 540.