I have a ‘Rescue’ pear which has gotten pear rust. It is about 3 years old. I also have an ‘Orca’ pear tree that so far this season does not have rust. Last year we had terrible rust. We thought maybe it came from a secondary host, because there were Juniper bushes. Now those bushes are all gone and I did clean up the leaves from last year to try and avoid contamination from the rust.
Also, I have never gotten any pears on either tree. The Orca tree is a bit older, about 5 years old. They both were bought from Raintree Nursery.
Sorry to hear about your pear with rust, and about the lack of fruit. Washington State University’s HortSense website says there are two types of rust that affect pears in our area:
“Two pear rusts which occur in Washington are Pacific Coast pear rust and pear trellis rust. Both require an alternate host. The rust fungus causing Pacific Coast pear rust is also found on hawthorn, apple, crabapple, serviceberry, quince, and mountain ash. The alternate host is the incense cedar (Calocedrus decurrens), which develops witches’ brooms. Infected fruits of pear are deformed and drop prematurely. On the surface of the fruit, yellowish spots with cup-shaped pustules develop. Leaves and green shoots may also be infected. Symptoms are most obvious after flowering and before July. Pear trellis rust may also infect pears, causing reddish to orange blotches on leaves. The alternate host is juniper, which develops elongate, swollen galls along branches.”
The only controls they recommend are cultural:
- Avoid susceptible varieties such as ‘Winter Nelis’.
- Collect and destroy fallen fruit beneath trees.
- Plant resistant varieties such as ‘Bartlett’.
- Prune out and destroy rust-infected tissues in pears and alternate hosts.
- Remove alternate hosts in the vicinity of pear trees, when practical.
Here is an article from British Columbia Ministry of Agriculture and Food on managing this disease in the home orchard.
It sounds as if you are doing everything you can to prevent a recurrence. The web resource above also states that fungicide is probably not a worthwhile approach to managing rust on pears or junipers.
As for the lack of fruit on your trees, Raintree’s pollination chart shows that ‘Rescue’ and ‘Orcas’ should cross-pollinate. It is possible that the ‘Rescue’ pear is not mature enough, or that its bout with disease slowed it down.
Here is an article about failure to produce fruit, from University of Maine. It mentions possibilities such as immature tree(s), lack of sun, and frost damage to flower buds.
I have an ‘Orcas’ growing without other pears in the garden, and yet it produces fruit, so I wonder if something else may be happening. Do you have a good number of bees and other pollinators in your garden? Do you or nearby households use pesticides that might interfere with pollinators? Here is information on protecting and encouraging pollinators, from U.S. Fish and Wildlife.
I also recommend contacting Raintree to see if they have any advice.