Apple tree mold? - Ask Extension
I have a young (planted 4 years ago) apple tree that is leading and blooming but I am concerned as there appears to be a white mold or mildew that is ...
Knowledgebase
Apple tree mold? #825238
Asked April 11, 2023, 5:35 PM EDT
I have a young (planted 4 years ago) apple tree that is leading and blooming but I am concerned as there appears to be a white mold or mildew that is growing on various parts of the tree. I’m attaching photos of what it looks like now. I have been spraying with a multi-purpose fungicide (Spectricide Immunox) to treat/manage cedar rust etc. What is this growing in my tree? Should I be concerned? And how do I treat? Thank you kindly for your consideration .
Prince George's County Maryland
Expert Response
Hi- the white, waxy fuzz is a sign of wooly apple aphids. They are attracted to wounds like pruning cuts and were much more noticeable last year following the 2021 17-year periodical cicada phenomenon.
WAA feeds on foliage and roots. They can become a major problem if left un-checked. Beneficial insects often help to reduce aphid populations.
We suggest you remove by hand all of the colonies you see. Hort oil and insecticidal soap cannot penetrate the wax. The white wax is protecting egg masses and immature aphids. Look closely at the lower trunk as well. Monitor for signs of WAA through the growing season.
Web pages:
https://entomology.ca.uky.edu/ef219
https://extension.psu.edu/tree-fruit-insect-pest-woolly-apple-aphid
https://extension.usu.edu/pests/ipm/notes_ag/fruit-woolly-apple-aphid
Jon
WAA feeds on foliage and roots. They can become a major problem if left un-checked. Beneficial insects often help to reduce aphid populations.
We suggest you remove by hand all of the colonies you see. Hort oil and insecticidal soap cannot penetrate the wax. The white wax is protecting egg masses and immature aphids. Look closely at the lower trunk as well. Monitor for signs of WAA through the growing season.
Web pages:
https://entomology.ca.uky.edu/ef219
https://extension.psu.edu/tree-fruit-insect-pest-woolly-apple-aphid
https://extension.usu.edu/pests/ipm/notes_ag/fruit-woolly-apple-aphid
Jon
Thank you so much!!
Sent from my iPhone
Sent from my iPhone
On Apr 12, 2023, at 9:16 AM, Ask Extension <<personal data hidden>> wrote:
You're welcome. Good luck!
Jon
Jon
