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Cedar Apple Rust

Authors: Aaron Bergdahl, Joseph Zeleznik


  • Disease affects cedars, junipers, apples, and crabapples.
  • Yellowish-orange lesions develop on leaves and fruit of infected apple/crabapple trees. Juniper-infecting spores develop in these lesions.
  • New infections on junipers result in small galls (or witches'-brooms) that, in moist conditions produce orange gelatinous structures that infect apple/crabapple hosts.

 Cedar Apple Rust - Esther McGinnis

Figure 1. Yellow to orange lesions are smooth on top of the leaf (Esther McGinnis, NDSU)

Cedar Apple Rust - Esther McGinnis

Figure 2. The spore-producing structures are raised on the back of the leaf (Esther McGinnis, NDSU)

Cedar Apple Rust - Aaron Bergdahl

Figure 3. Cedar apple rust fruiting bodies on juniper (Terry S. Price, Georgia Forestry Commission,


Management and other important facts

  • Do not plant the juniper/cedar and apple hosts closely together because both are required for infection.
  • Picking the galls or pruning the witches'-brooms off the junipers may mitigate the disease.
  • Several species of this pathogen are found in North Dakota. 
  • Several apple and crabapple cultivars are resistant to cedar-apple rust.




This website was supported by the U.S. Department of Agriculture’s (USDA) Agricultural Marketing Service through grant 14-SCBGP-ND-0038.
Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.

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