Pear Rust - Bartlett

Asked July 24, 2018, 10:45 AM EDT

Hello, Today I found a leaf on my new (this spring) Bartlett tree with a rust spot. How can I treat this? How can I keep it from spreading? I have another new pear (Orcas) on the other side of the yard (50 feet away). I have not yet seen it on the other tree.

In terms of conifers, I do not have an incense cedar, which I read is an alternating rust host. I do have small dwarf Japanese cedars: cryptomeria Japonica 'globusa Nana' and gold cone junipers.

Alternately, if it is not treatable and will kill future pear harvests, are there other fruit trees that are not susceptible?

I'm on a residential lot in Milwaukie (not in a rural area). There are large cedars in the neighborhood.


Thank you, Alexandra

Clackamas County Oregon disease issues fruit trees pears horticulture

3 Responses

Rust does not automatically destroy a crop every year. Infection intensity varies from one year to the next, depending upon the weather.

Further, two different kinds of rust are possible on pear, each with its own alternate host: incense cedar for Pacific Coast Rust, juniper for Pear Trellis Rust which arrived n Oregon approximately 3 years ago.

No chemical products are available for use by home gardeners for either kind of rust. If you want the trees sprayed, you will need to hire a professional spray company.

In the meantime, remove and destroy all rust-affected leaves and fruits. And consider doing the same with the alternate hosts.

Thank you. I do have two junipers. They are only a few feet tall at this point, and replaceable. If I am very interested in the pear crop, and don't want to hire someone to spray chemicals, is removal the safest choice?

What a great service! Thank you for your help.






Depends upon which rust the tree has.

Please send images of typically affected leaves, both top and bottom surfaces.