Hi, I have a very young apple tree, planted this spring and only 5ft
tall. I've just noticed some flat brown patches on some of the
leaves, and wonder whether you knowledgeable folk could tell me what
it is? Is it some kind of fungus I can spray against?

I'm worried it may be some horrible disease that I need to "nip in the
bud". The tree is otherwise thriving - I've kept it reasonably
watered throughout the dry spell here in Hants.

Thank you.
Barb