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Apple problem #926346

Asked March 19, 2026, 7:51 PM EDT

How to treat a disease on my Zestar apple tree.

Douglas County Minnesota

Expert Response

Hi Barry,

Thanks for reaching out. Is this a photo of an apple that you have stored throughout the winter? If so, it could be a problem with the storage: https://extension.umaine.edu/fruit/harvest-and-storage-of-tree-fruits/storage-disorders/ Brown spots can occur when the apples are stored in too cold of temps.

If not, a photo of the outside of the fruit could be helpful. It might be codling moths or apple maggots: https://extension.umn.edu/yard-and-garden-insects/codling-moths or https://extension.umn.edu/yard-and-garden-insects/apple-maggot if this occurred last year during the summer.

I hope this helps!

An Ask Extension Expert Replied March 19, 2026, 9:30 PM EDT