Could someone tell me what the pest or diease is that my two pear trees have developed this year. The leaves have an orange circle on them with a growth of sorts on the underside. No fruits have developed this year. What is the diease and how can I get rid of it? Will the trees fruit next year?
Pear rust spores are carried and spread mainly by Juniperus chinensis.
If you have any of these near your trees, get rid of them. In Switzerland these have to be reported to the local councils who then come to eradicate them.
See also the following site: