Spruce broom rust
Needle, Leaf, Branch
Damage, symptoms and biology
The infection causes the formation of witches brooms, with yellowed needles. Orange spores appear on the needles in late summer.
Spruce brooms are often associated with stem deformations, reduced increment growth, broken tops, and tree mortality. Rust brooms also serve as infection courts for decay fungi such as Phellinus pini contributing to increased levels of damage.
The brooming symptoms caused by C. artcostaphyli could be confused with mistletoe infections. However, distinguishing features of the rust are the complete loss of needles in the winter and the yellow-orange colour of the broom in the spring and summer.
Canadian Forest Service Publications
Information on host(s)
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