Trellis Rust on pears in May or other infection? - Ask Extension
We live in Portland and have a pear tree with multiple grafted types in the garden since 4 years now. It was doing well until it caught Trellis Rust l...
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Trellis Rust on pears in May or other infection? #868755
Asked May 16, 2024, 3:48 PM EDT
We live in Portland and have a pear tree with multiple grafted types in the garden since 4 years now. It was doing well until it caught Trellis Rust last fall (2023). We picked off the infected leaves and bagged them up, hoping for the best, but this spring (2024) it seems to have started again - or maybe it is something else? The local nursery says to spray with Liqui-Cop but we would prefer not to use anything harder than Neem oil or maybe sulfur. As far as I can tell, the Liqui-Cop is not going to do much anyway. We suspect we might have to remove the tree.and try something else in that spot.
Could you help identify the infection and advice on our options?
The grafted types are Luscious pear, Seckel pear, Flemish Beauty and Summercrisp pear. Unfortunately I don't know what the root stock is but it's a semi-dwarf, 12' - 15' high. I included pictures of the Luscious pear - the only branch with fruit this year, but I have pictures of the other leaves with varying degrees of infection. The Seckel pear branch seems less infected than the rest.
Multnomah County Oregon
Expert Response
More pictures.
More pictures.
Looks like you have mostly pear mites and a little rust. The mites are very common and you generally see symmetrical symptoms on either side of the mid-rib. Here is the information on those critters:https://pnwhandbooks.org/insect/tree-fruit/pear/pear-eriophyid-mite
As for the rust, this one is a bit different as it is not trellis rust but likely Pacific Coast Pear Rust which cycles on incense cedar trees: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-pacific-coast-pear-rust
Let me know if you need more information or have questions after reading the sites.
As for the rust, this one is a bit different as it is not trellis rust but likely Pacific Coast Pear Rust which cycles on incense cedar trees: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-pacific-coast-pear-rust
Let me know if you need more information or have questions after reading the sites.
Thank you so much!
We plan to spray for the blister mites with an OMRI-listed Pyrethrum now, and then with an OMRI-listed lime-sulphur come fall and again just before bud-break next year. Also, we will keep removing rust-infected leaves and fruit. We have two follow-up questions we hope you could answer:
1) Do you have a hunch as to whether the two rusts are likely to be recurring annually?
2) Does the infected tree pose a threat to other fruit trees in the area? (We have a number of apple trees we are very fond of)
Thank you again and very best regards!
The rust will be there most years, sometimes heavy and sometime light. The problem is the conifer that the rust fungus is also on. Your pears are getting sores from conifers and not from other pears or roseaceous hosts.
