Curly leaf disease plum tree

Asked June 14, 2018, 3:54 PM EDT

I have a 3 year old Santa Rosa plum tree. It is showing some signs of disease. See photos. Some of the new leaves are abnormally curled/deformed. It has a few healthy looking green plums, but also a tiny yellow plum. Is this curly leaf disease? Any treatment suggestions. I also have a nearby 5 year old Itslian Brooks pplum tree looking healthier but a few branches with simalar looking leaves.(3rd photo)My 2 year old shiro plum looks ok.

Multnomah County Oregon plant disease identification plum trees horticulture

3 Responses

Your plum tree has several common issues.

The severely curled/distorted leaf in top center of the first image may have been fed upon by aphids. To verify, uncurl the leaf and look inside the curls and tell me what you see. (An image will be helpful, also.) Perhaps you'll find small aphids or the debris that remained after they died.

The small holes in the leaves are due to shothole, a common disease with plums and peaches. You’ll need to apply a spray every year to manage the disease. (It’s too late to spray now.) //

Cultural management includes –

- Do not allow sprinkler irrigation water to wet tree foliage and fruit.

-If twigs have died, remove them during pruning if practical.

Chemical treatment is also needed –

- Spray twice:

(1) At 50% leaf fall in late autumn to help protect leaf scars and again during the dormant season (when the tree is leafless). Use one of the following: Hi-Yield Captan; Monterey Liqui-Cop; Bonide Liquid Copper Fungicide.

(2) Spray again at shuck fall (the small brown protective flakes around the baby fruit) in spring to protect fruit.

The small plum that has yellowed will soon drop. It may not have been pollinated. (Lack of pollination occurs with some fruits every year.)

Thank you for the advice. This is s fantastic resource!
a couple of follow up questions
1. Curly leaves- I didn’t find aphids, but there was a white sticky insect like substance and a couple of brown things, ??? Dead bugs??? See photo 1
2. Spraying trees - you said “twice but
your description is 3 times, late fall, dormant (winter) and spring. Is 3 the correct amount?

I'm unable to see the insects. But from your description, they may be aphids killed by a very small beneficial insect.

Sorry abut the error in the comment re spraying. Three applications is correct.