Cedar-apple rust - Ask Extension
We have a small orchard and for the first time this year we’ve found cedar-apple rust. We do have several cedars on our property and suspect we noti...
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Cedar-apple rust #872151
Asked June 08, 2024, 8:08 AM EDT
We have a small orchard and for the first time this year we’ve found cedar-apple rust. We do have several cedars on our property and suspect we noticed the fungal pods (looking like small nuts) on the branches a couple summers ago, but didn’t know what they were. I’ve been researching how to treat the trees, but was wondering if removing the cedars would most likely resolve the issue over time? I’m not certain it’s an option I like, but may be willing if it would help in the long run.
Thank you for your time.
Eaton County Michigan
Expert Response
Hello,
This can be a tricky pathogen to manage, but there are some strategies used by commercial orchards that you may be able to incorporate into your orchard management.
Removal of the cedars may not help your situation unless you know that there are no other cedars for miles around. Wind can disperse the spores quite far. This is why it is also not that effective to prune off the galls. If there are trees with galls within a few miles, you can still get spores blowing in.
There are some effective fungicides you can use. The fungicides used to manage this fungus need to be applied weekly from the time of flowering to the time the galls have dried up and fall off. Sterol inhibitors are the most effective fungicides against cedar-apple rust. These are widely used in apple production.
Going forward, looking for resistant apple varieties can be a good practice. Also making sure there is good air flow around/within your trees is important in reducing fungal infections. If you are looking to raise your apples organically, tolerating spots on the apples might be necessary. Here is a good article about management of cedar-apple rust.
https://ohioline.osu.edu/factsheet/plpath-tree-10
Thank you for contacting Ask Extension.
Ruth
This can be a tricky pathogen to manage, but there are some strategies used by commercial orchards that you may be able to incorporate into your orchard management.
Removal of the cedars may not help your situation unless you know that there are no other cedars for miles around. Wind can disperse the spores quite far. This is why it is also not that effective to prune off the galls. If there are trees with galls within a few miles, you can still get spores blowing in.
There are some effective fungicides you can use. The fungicides used to manage this fungus need to be applied weekly from the time of flowering to the time the galls have dried up and fall off. Sterol inhibitors are the most effective fungicides against cedar-apple rust. These are widely used in apple production.
Going forward, looking for resistant apple varieties can be a good practice. Also making sure there is good air flow around/within your trees is important in reducing fungal infections. If you are looking to raise your apples organically, tolerating spots on the apples might be necessary. Here is a good article about management of cedar-apple rust.
https://ohioline.osu.edu/factsheet/plpath-tree-10
Thank you for contacting Ask Extension.
Ruth
