yellow blueberry leaves with necrotic freckles

Asked August 2, 2019, 3:37 PM EDT

On the pair of Duke blueberries two days ago, I noticed yellow leaves with necrotic spots.
What can be the cause of this occurrence on the leaves. Blueberries are in post-harvest phenophage.
Here are pictures of blueberries.

Best regards and thanks for your response and help
Nick

Michigan blueberries blueberry diseases yellow leaves

4 Responses

I have never seen anything like that in Michigan Blueberries. It is not a soil pH problem which would cause the newer leaves to be yellow with green veins. Tip burn looks like drought but that would be the newer leaves as well. What did you spray on them. How often are they watered and where does the water come from?

Weed grass in the row space was treated with herbicide, but only 15 cm in height, while the weeds around the plants were hand-picked. Also, 2-3 days of blueberries were not irrigated enough.
Maybe that can be the cause of these symptoms.

If the yellow leaves are only on the bottom of the plant I would agree the the herbicide spray might be to blame. Usually the grass herbicides are really safe but the oil carrier can cause problems on hot days. Some of it does look like spray injury

Professor Mark Longstroth, thank you very much for your help.
best regards
Nick