Young plum and cherry: brown holes in leaves

Hello fellow growers!

I'm new to all of this. Last fall, we planted 6 fruit trees, amongst which a cherry and a plum. The other four trees are doing fine, but the plum and the cherry have leaves turning yellow with brown blotches, and even lose some leaves. We're in central austria, the soil is mostly clay, it hasn't been particularly dry or wet. The trees are in direct sunlight for most of the day.
I'm attaching a few pictures, can anyone give me a pointer what I should be looking for? Is this due to the soil? Due to some fungus? Insects?

Thanks for any help!

EDIT: corrected prune to plum

By Prune I assume you mean a plum tree ?
What other fruit trees did you plant and how far away are they from the plum and cherry ? Have you used any mulch ?

David

David Livingston wrote:By Prune I assume you mean a plum tree ?
What other fruit trees did you plant and how far away are they from the plum and cherry ? Have you used any mulch ?

Yes, sorry, plum (not so good with the english names).
There's a walnut, a pear, an apple (Jonagold) and a multi-apple (5 different apples) within 10 meters.
I've added about 20kg of soil (per tree) when planting, no mulch, there's grass growing beneath the tree (about knee high).

Look up leaf shot. Do you have it on peaches too?

Can be treated but my prior experience is not favorable from pruning/conservative controls. I only could cure it with a decidedly non-permie solution.

I agree with TJ that it looks like leaf spot (I think TJ had a typo, it's spot not shot from my research) - It's a fungal pathogen, and I'm wondering if there are some fermented herbal sprays that include garlic, other aromatic herbs, nettles etc. that could be effective for this. I'm about to move from Oregon to Florida and my Holistic Orchard book by Michael Phillips is packed away. That would be a good resource to check out. Other than herbal sprays which can use friendly bacteria and microbes to combat the fungus on the leaves, I've read that removing the infected leaves from the trees and ground around them, and making sure the area has plenty of air circulation and sun will help to deter the fungus from proliferating. Best wishes, and do add some mulch if you can.. wood chips that leave about 10 cm of space around the trunk will help the trees roots grow strong, help the soil come to life, and make a situation where the tree's natural strength and immune system are better supported. Send me a PM if you want to chat a bit more - Pete

(I think TJ had a typo, it's spot not shot from my research

Yup. I honestly haven't looked at the common names for a long time. We called it shot-hole, leaf shot- basically it meant tree needs to be destroyed.

Generally in my experience these come infected from the nursery, where they are grown very close together, watered from above and very often kept humid in a growhouse. I have never successfully treated one with the measures noted above. If anyone else has been able to do so, please update. I think foliar feeding may hold promise, it seems to work for Stefan Sobkowiak. He is way past me in knowledge. If you haven't watched Permaculture Orchard you are missing a great film and some awesome motivation! But and I stress, you may be better off removing the tree. I lost three trees next to a sick Santa Rosa because I was too stubborn to cut my losses.

Phytophtora and Armillaria are also issues with the recommended mulching. They do not have to be next to the trunk to do their deed. I personally had been mulching and inoculating with desired mycorrhizae but this is based on principle and not science, in fact I would say I was probably wrong. After reading some comments on here I quit doing that and am adding compost only as a top dressing, no wood chips at all.  

Grass under young trees is extremely stressful to them. Pull out the grass completely, especially the roots and then mulch over the area so no weeds or grass regrows in the area.

If the holes were random and there was no yellowing I would say it was a caterpillar, such as tiger swallowtail or a sphinx moth, but since you are in Austria, I do not know the insects that are hosted on Prunus species.

Overall the trees look rather healthy, so keeping up with growth, reducing stress etc may allow you to simply prune off the area that are effected and spray with a herbal retardant.

All the best!