Cedar-Apple Rust

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This article was published originally on 4/28/1993
Byline:
by Paula Flynn, Department of Plant Pathology
During warm rainy days in late April and early May, cedar trees infected with the cedar-apple rust fungus will develop bright orange, gelatinous galls.
Cedar-apple rust is an interesting disease. It requires both an apple and cedar or juniper to complete its life cycle. On the cedar, the fungus produces reddish-brown galls that are up to golf-ball size on young twigs. During wet weather these galls swell and begin to push out bright orange gelatinous tubular structures. Wind carries fungal spores from these gelatinous structures to susceptible apple or crabapple cultivars.

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