Cedar-Apple Rust

Asked May 14, 2020, 11:18 AM EDT

Hello! I have six small apple trees under 6 ft. tall. They were all planted in the last three years and have not flowered or fruited yet- 2 Cortlands, 2 Fujis, and 2 Hyslop Crabapples. A huge cedar is on the adjacent property, 20 yards away. For the first time it had orange fungi this spring which have now turned brown. -Are these varieties of apples susceptible to the fungus? -If so would you recommend spraying the apple trees? They are all beginning to leaf out to some degree. - If you recommend spraying is there an organic fungicide or treatment you would recommend? Thanks for your help, I appreciate it!

Shiawassee County Michigan

1 Response

Hello,

Cortland is listed as susceptible. All apples and pears are susceptible to some extent. Ask your neighbor if you can prune the galls of the cedar to reduce spores in your area. Here are details, with treatments, timing.

https://www.canr.msu.edu/ipm/diseases/cedar_apple_rust#gallery

https://plantpathology.ca.uky.edu/files/ppfs-fr-t-18.pdf

This booklet has good pictures of bud stages, should you need them-

https://www.extension.purdue.edu/extmedia/ID/ID-146-W.pdf

This is an organic spray schedule-

https://s3.wp.wsu.edu/uploads/sites/2086/2014/05/organic_spray_home_apples_pears1.pdf