Bradford Pear problem

Asked June 16, 2017, 2:01 PM EDT

Our two 20 year old Bradford Pear trees have developed a problem and are dropping many leafs. They have pencil erasure sized rust colored spots on the leaves. Will this kill the trees? Is it treatable now? If not, what do I need to do to prevent it in the future? What is the name of the disease or problem?
Thank you very much for taking time to help us.
Sincerely,
Barney S

Livingston County Michigan trees and shrubs pear diseases pear rust

3 Responses

Yes it is a rust and yes it is too late to treat this year.
This rust is or is related to cedar-apple rust.
https://en.wikipedia.org/wiki/Gymnosporangium_juniperi-virginianae
Not sure which disease goes to Bradford pear but control will be similar.
There are a lot of fairly specific diseases which have a complex lifecycle where they infect 2 different species. The disease overwinters cedar or Juniper trees. You will see galls on these trees in the early spring, which become orange and gelatinous in the spring and infect your pear. The wet spring was good for this disease. You need to protect the tree from when the flowers become visible for about a month. Captan which is a common fungicide for home fruit growers is weak on rust diseases. I would suggest a material call Immunox Multipurpose fungicide. This material needs to be applied about every 10 days or immediately following a rain to protect the leaves and fruit. You might keep you eyes open for the galls on any juniper trees in your area.

Here is a link to an Illinois publication which has a link to the different types of rust.
http://extension.illinois.edu/focus/index.cfm?problem=cedar-apple-rust

One of my colleagues correctly diagnosed this disease as European Pear Rust.
Here is a link to more information.
https://ask.extension.org/questions/407743