Dwarf cherry ?virus?

Question: Hello, 
I’m an urban renter with an out-of-town landlord. The approx. 12 y/o dwarf cherry in the front yard is looking really ill, with all its leaves showing brown and wilting. 
I’ve always trickle watered it several times throughout the hottest part of the summer.

responder: Deb K  Replied September 04, 2024, 7:39 PM EDT
response: Thanks for contacting ask extension with your concerns about the dwarf cherry tree.   It looks like the tree has a bacterial or fungal disease. I have several questions that will help with the diagnosis.  How was the tree last year? Did you see a similar problem?  When did you notice the leaf spots/drop this season.      Did the tree produce fruit this year?  Take a look at the trunk and limbs. Do you see cankers or ooze?   Have you applied any dormant sprays in past years? If so, what have you used. How often and how long are you watering the tree? Looking forward to hearing back from you.

responder: The Question Asker Replied September 06, 2024, 1:34 PM EDT
response: Thank you for getting back to me so quickly. So, I’ve never sprayed/treated the tree, only occasionally watered during the summer. I would generally do a very slow overnight watering every couple weeks until the weather cooled. It’s always had a good crop of healthy, tasty red cherries. Several years ago the tree and residence were infested by small sugar ants, but the landlord has since been forced to regularly treat the residence foundation with a pet safe treatment (?) and no problems since. The crop this year was markedly different, although blossoms were bounteous there wasn’t much fruit, they were small and watery tasting. The branches and bark look normal and consistent. I noticed the leaves looking a little wilted at the top of the tree about mid July, and attributed it to the heat and that I had been out of town and not watered it since beginning of June, but it didn’t perk up with resuming watering, and as I say, the fruit this season was disappointing. Thank you,DebraSent from my iPhone On Sep 4, 2024, at 4:39 PM, Ask Extension wrote:﻿

responder: Deb K  Replied September 08, 2024, 3:52 PM EDT
response: Thanks for your reply!  It looks like you have leaf spot.  To control it for next season you need to rake and destroy fallen leaves. Do not use the leaves as a compost near your tree. Next spring at shucksplit  stage, spray your tree with either captan, chlorothalonil, myclobutanil, or propiconazole. (Note: The shuck is the dried floral remnant which in the stone fruits partially covers the newly-set fruit. As the fruit grows, the shuck splits and soon is sloughed off.  This process is known as shuck split. As the cherry continues to expand, the shuck eventually falls off. This stage is known as shuck fall.) Be sure to follow all directions listed on the table of the pesticide. Use only as directed.   The ants in the cherry tree may have been harvesting aphids. Ants like the honeydew that aphids produce and will actually protect them from predators. Your tree currently does not show symptoms of aphids but you might want to keep an eye out for them. Next summer If aphids appear in large numbers, you could spray with Beauveria bassiana, esfenvalerate, insecticidal soap, malathion, pyrethrins, or neem.     I recommend you water a little more regularly. In general fruit trees like a deep soak (2–3 inches of water) every 10–14 days on sandy soil and every 15–20 days on clay soil. In western Oregon, fruit trees need to be watered starting in mid-June and ending in late September.  Be sure to water all around the drip line of the tree and not near the trunk.  Please contact us if the leaf spot returns next season.

responder: The Question Asker Replied September 12, 2024, 2:04 PM EDT
response: Again, thank you!Are there any organic anti fungal options?Debra Sent from my iPhone On Sep 8, 2024, at 12:52 PM, Ask Extension wrote:﻿

responder: Deb K  Replied September 12, 2024, 2:34 PM EDT
response: Sorry,  There are no organic fungicides listed as approved for home orchards.  If you decide not to spray, be very diligent about removing fallen leaves.