Apple tree blight

Question: What is affecting this espaliered 5-yr-old Gala apple tree for the second year in a row?  The tree is producing many apples and appears otherwise healthy.

responder: Jacki D., Master Gardener Diagnostician Volunteer (Washington, Multnomah and Clackamas Counties) Oregon State University Extension Service Volunteer Metro Master Gardeners (http://metromastergardeners.org/) Replied July 03, 2023, 7:40 PM EDT
response: Please share a couple more photos of a leaf with “some” early spots, not heavily infected. This page has photos of three types of leaf spots on apples. Do yours make lumpy structures on lower side? How are the apples? Scab often damages fruit as well as leaves. While we wait to identify the issue with your leaves, check out the general “Managing diseases and insects without using pesticides” in EC 631. When only a few leaves are infected with fungal or bacterial blights, removal of those leaves, good sanitation year-around, and pruning for good air circulation is part of the standard recommendations.

responder: The Question Asker Replied July 04, 2023, 6:28 PM EDT
response: Thank you for your response.  Regarding questions:   Lumpy structures on lower side:  No.  Brown lesions seem to be flat (or very faintly raised) on both sides of the leaves (see 2 images of both sides of same 3 leaves) The apples:  they look fine at this stage; last year they also looked fine at this stage but I remember a large percentage of them as wormy, mushy, and generally inedible as the summer progressed (see 1 image of an apple cluster; all apples on the tree look like this right now)

responder: Jacki D., Master Gardener Diagnostician Volunteer (Washington, Multnomah and Clackamas Counties) Oregon State University Extension Service Volunteer Metro Master Gardeners (http://metromastergardeners.org/) Replied July 04, 2023, 9:29 PM EDT
response: Did you learn what was wrong with the apples last year? Some pests and diseases attack both leaves and fruit. Take clear photos of apples this year. I’ll refer this to another expert. I’m just not sure about these leaves.

responder: The Question Asker Replied July 04, 2023, 9:47 PM EDT
response: Thank you, Jacki, for your amazingly prompt reply . . . and on a holiday, too!  No, we didn’t learn what was wrong with the fruit or the leaves last year, just thought whatever it was would go away and never return.  Denial is a river…I so appreciate your tackling this question and referring it to another diagnostician as needed.  We will do better by this apple tree this year with your help.PatriciaOn Jul 4, 2023, at 6:29 PM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Jay W. Pscheidt, PhD, Professor  Replied July 05, 2023, 11:46 AM EDT
response: Looks like a bad case of blister mites. Have a look here and see if it matches the symptoms you are seeing on your tree: https://extension.usu.edu/pests/ipm/notes_ag/fruit-blister-mites  One of your images looks like the leaves have some apple scab as well. Overall the tree seems to be doing fine. Keep up with the suckers at the base of the tree and keep an eye on those burr knots along the trunk.  (https://pnwhandbooks.org/plantdisease/host-disease/apple-malus-spp-burrknot)  As for worms, likely coddling moth and the publication suggested earlier should help you get after them. There are other insects such as apple maggot so make an id when you see them next.

responder: The Question Asker Replied July 05, 2023, 2:13 PM EDT
response: Dear Jay,We are on the case and will forever grateful for your expert advice and the OSU Extension service.PatriciaOn Jul 5, 2023, at 8:46 AM, Ask Extension <<personal data hidden>> wrote:﻿