Wok Swour

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).

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