Help diagnosing apple leaf problem

Asked May 22, 2016, 1:58 PM EDT

After this crazy moist and cool Spring, some of my apple trees are exhibiting a problem they have not exhibited before. I am enclosing a photo. The apple in the photo is only partly affected, but I have another in which 100% of the leaves are affected. The trees have not been sprayed yet this year. The affected apples are Honeycrisp and Goldrush and they are on EMLA-111 roots. Could you help identify the problem and suggest a remedy ? Thank you, Philip A in rainy Selbyville, Del.

Sussex County Delaware apples fruit plant diagnostics tree fruits

1 Response

Hello, You mentioned that the apple trees have not been sprayed yet this year. You probably should have put on an apple scab fungicide at bloom, and be on a regular fungicide spray schedule with this wet weather. However, the picture you sent appears to be possible herbicide injury. If there was herbicide applied to your lawn or to surrounding agronomist fields, it is possible that your trees received some injury from drift. Chemicals volatile (become air borne as gases) differently in wet humid weather. Is the damage on one side of the trees more so than the other? If this is herbicide exposure, the trees should grow out of it. The other possibility, but remote, is that this distortion is due to powdery mildew infection, which can cause distortion of new growth. I would suggest that you seen in a sample, so I can check it under the microscope. You can take a sample in to the Kent County Extension office at the Paradee Center in south Dover. I'll try to get back to you within a few days. Thank you for contacting Delaware Cooperative Extension, Nancy Nancy