Western Gall Rust
What is it?
Western gall rust (Endocronartium harknessii) is a common disease of hard pines, like Jack pine and lodgepole pine. Airborne
spores infect the green tissue of young shoots and cause the wood to swell into galls (globe-shaped clumps).
Where is it found?
The rust generally affects young pines throughout the province.
How to recognize it?
Look for the following signs and symptoms:
Branch and stem globe-shaped perennial galls caused by swelling of the wood rather than the bark are conspicuous and easy
Orange-yellow spores are produced within the bark tissue of the gall for 5 to 6 weeks every spring.
What's the concern?
Western gall rust is a common disease of hard pines. This disease often kills small trees that have main stem galls. However,
this disease does not usually kill mature trees. Stem galls cause growth losses and make trunks susceptible to breakage
from wind or heavy snow. Branch galls do not significantly affect the overall health of the infected trees but help spread
Western gall rust can affect aesthetic, recreational and economical values of our forests. It is economically important
in high value plantations, tree farms and nurseries. Unlike other stem rusts, this species does not need another species
of host to complete its life cycle; consequently, this rust can directly and more rapidly infect other pine trees.
What does Alberta do?
Alberta is not currently surveying for western gall rust. Alberta plays a role in education and awareness about western
gall rust and its management.
Where can I get more information?
Skip to breadcrumb trail
Posted May 1, 2009