Bartlett Pear tree orange rust - Ask Extension
I am looking for information on your website about a fungus that affects Bartlett Pear trees. It is sometimes called "Orange Rust" or "...
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Bartlett Pear tree orange rust #875354
Asked June 30, 2024, 2:13 PM EDT
I am looking for information on your website about a fungus that affects Bartlett Pear trees. It is sometimes called "Orange Rust" or "Pear Rust". My search only turned up information about cedar trees. I understand that cedar trees are involved in the cycle but I don't have a cedar tree, I only have a Bartlett Pear tree. Where would I find information related to Bartlett Pear trees? I have a tree that has orange spots all over it's leaves. This is the first year this has happened. I've included a photo of my pear tree's leaves.
Thank you for any assistance.
Multnomah County Oregon
Expert Response
Please share a photo of the leaf underside to confirm this is a rust. This blog from OSU is one of the most succinct articles I’ve seen. The resources linked provide more details.
Here is a photo of the underside of 3 Bartlett pear tree leaves. Any additional information or suggestions is appreciated.
I read the article by Jean Natter and concluded that it would be difficult to protect the pear tree from pear rust. The tree is located in NE Portland in a neighborhood where lots are relatively small. We might look into have a service spray the tree but that depends of possible downside consequences of spraying chemicals. Perhaps the answer is to plant disease resistant trees.
Thank you
I believe your diagnosis to be accurate. You are also right in that its other host (it needs both pear family hosts and incense cedar) could be some distance away and the spores moved by wind. The disease is worse some years and not seen much in others. We had a lot of rain this spring with strange 70 degree patches in between.
Here is the PNW Plant Disease Handbook on the subject: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-pacific-coast-pear-rust
There is a newer rust (here) that goes from juniper to pears that might be it but the treatments are more or less there same. https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-trellis-rust-european-pear-rust
The Handbook guidance is mainly focused toward commercial pear growers.
None of the listed fungicides are available to homeowners according to the PNW link. So if you were seeking treatment, you would need a commercial firm to do the treatment. Since the disease is rather sporadic, you might try living with it, knowing there will be mostly good years with low disease presence and some bad ones. I hope this helps. Please feel free to respond to this through Ask Extension or directly at <personal data hidden>. Chip Bubl. OSU Extension Agent/Columbia County (retired)
Here is the PNW Plant Disease Handbook on the subject: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-pacific-coast-pear-rust
There is a newer rust (here) that goes from juniper to pears that might be it but the treatments are more or less there same. https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-trellis-rust-european-pear-rust
The Handbook guidance is mainly focused toward commercial pear growers.
None of the listed fungicides are available to homeowners according to the PNW link. So if you were seeking treatment, you would need a commercial firm to do the treatment. Since the disease is rather sporadic, you might try living with it, knowing there will be mostly good years with low disease presence and some bad ones. I hope this helps. Please feel free to respond to this through Ask Extension or directly at <personal data hidden>. Chip Bubl. OSU Extension Agent/Columbia County (retired)
