ID apple disease?

Asked June 3, 2020, 12:42 PM EDT

Can you help us identify what is killing leaves on 1 row of Pink Lady apples in the our orchard? This has developed in just the last month. Some new leaves are yellowing and others are turning red and brown. Outside of Antelope, elevation 1500 ft, and effected trees are on the SE facing side of orchard. Other varieties of apples and pears seem to be om for now.

Wasco County Oregon

1 Response

Hi,

It looks like you have a few things going on with these trees. In photos one and three, I notice that leaves are turning light yellow while the veins are a dark green color. This is called interveinal chlorosis. Interveinal chlorosis is a common symptom of a nutrient deficiencies. In this case, you are likely experiencing an iron deficiency. The leaves are likely turning brown due to burning caused by southern sun exposure on a leaf containing very little chlorophyll. Sometimes this can be corrected by lowering your soil pH if it is above 7. I would suggest taking a soil sample for testing to confirm that pH is the issue. You may also consider applying a fertilizer containing iron.

In the second photo, the leaves and wood have a black burnt appearance. Our weather recently has been warm and wet. It is likely that this is fire blight, a bacterial infection of the tree. I suggest looking at this branch and identifying where the burn appearance stops and pruning out all of the tissue up to 18 inches below that.