Why do my honey crisp apples have dark spots? - Ask Extension
My honey crisp apples, have skins with dark spots. What can I do to cure that?
Knowledgebase
Why do my honey crisp apples have dark spots? #601575
Asked October 08, 2019, 7:46 PM EDT
My honey crisp apples, have skins with dark spots. What can I do to cure that?
Pine County Minnesota
Expert Response
Black spots does not tell me much. The spots could be several things, apple scab, bitter pit, black or white rot or even fly speck.
Below are links to each and measures to control
Apple scab https://www.canr.msu.edu/ipm/diseases/apple_scab is controlled with fungicide sprays early in the season from when green tissue first appears until about a month after bloom when the fruit becomes waxy and resistant to the fungus. There is also a window of vulnerability late in the season when the fruit can develop pinpoint scab.
Bitter pit https://www.canr.msu.edu/ipm/diseases/bitter_pit_and_cork_spot is a calcium disorder that is common in Honeycrisp especially when the fruit are large. It is corrected by including calcium in the cover sprays applied after bloom to the cover sprays of insecticides and fungicides to protect the fruit. Here is another article on managing bitter pit https://fruitgrowersnews.com/article/reducing-risk-bitter-pit-honeycrisp-apples/
Black rot https://www.canr.msu.edu/ipm/diseases/black_rot_blossom_end_rot_frogeye_leaf_spot is what we call a summer rot, these are a problem in regions with warm wet summers and are controlled bu applying fungicides to the fruit during the summer. White rot is also a summer disease.
Sooty blotch and fly speck https://www.canr.msu.edu/ipm/diseases/sooty_blotch also cause black spots on the fruit. These fungi actually live on the waxy coat of the apple and do not harm it at all. They appear when fruit is wet for long periods of time allowing the fungus to become established. Commercial growers include a fungicide in several of their cover sprays to control this disease.
If you do not think it is any of these causing your black spots let me know. If so a picture would be helpful
Thank you!
here is a photo of my honey crisp apples. You stated that it was hard to tell without seeing them.
thank you for your advice on what I can do to prevent this in the future
best regards, Jane Eastling
here is a photo of my honey crisp apples. You stated that it was hard to tell without seeing them.
thank you for your advice on what I can do to prevent this in the future
best regards, Jane Eastling
Most of those spots are sooty blotch. It is really only cosmetic. It should be reduced by some fungicide applications during the summer. Some are some insect stings where an insect has pierced the skin while feeding. Do you spray at all?
No, we don’t spray at all.
whst is the product which we should be spraying?
thank you so much for your help!
whst is the product which we should be spraying?
thank you so much for your help!
Surprised you don't get scab. The fungicide Captan should be effective. You can find it in the garden sections of most large stores. Garden stores will have a more complete selection of home pesticides.
For home apple grower sprays where you need to protect against insects, and diseases I recommend this short resource from the University of Kentucky https://plantpathology.ca.uky.edu/files/ppfs-fr-t-18.pdf
Ohio State has developed a good resource on home fruit tree care.
https://extensionpubs.osu.edu/midwest-home-fruit-production-guide/
It is available from many states for free as a PDF. Here is one from Kentucky.
https://plantpathology.ca.uky.edu/files/mw_home_fruit_productn_b591.pdf
Purdue also has a good resource for pest control for the home gardener for both tree fruit, grapes, strawberries and raspberries.https://www.extension.purdue.edu/extmedia/ID/ID-146-W.pdf
