Answer: Without inspecting your pear trees, it's difficult to diagnose the problem. It could be cultural, but it might also be a disease that's causing the symptoms you describe. Carefully inspect the twigs and branches for discolored areas and cankers (sunken areas or raised areas). If either are present, you could be dealing with scab or fire blight. If neither are present, the problem could be powdery mildew. I highly recommend you take samples of the affected leaves plus a fruit or two to your local Cooperative Extension Office for professional diagnosis. Helpful folks there can positively identify the problem (or will send it to WSU's plant diagnostic lab in Puyallup). They will also provide control recommendations. Contact:
Washington State University Thurston County Extension
720 Sleater-Kinney Road SE, Suite Y
Lacey, WA 98503
Best wishes with your pear trees!
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