I have a 12 year old Bartlett pear that I topworked to several Asian varieties and 2 additional Ubileen grafts about 5 years ago. This year I noticed leaf spot for the first time in my orchard, involving only this tree and only on the Bartlett and Ubileen sections. I removed the remaining branches with Bartlett leaves and sprayed the tree with myclobutanil. No signs of psylla.
I'm considering now what to do with the Ubileen part of the tree. This consists of two 5 year old multibranched grafts, each about 8 feet long. I'm considering pruning them back sharply, heading off each lateral shortly after it comes off the leader, so that no leaves will be left on that part of the tree. This has the advantage of removing all diseased leaves from the orchard and hopefully keeping the disease from spreading to my other pear trees and not significantly damaging the Ubileen .From those experienced managing this disease I would appreciate your comments on my proposed plan.