On 02/10/2014 14:23, mark wrote:
I have some small but established apple trees. The soil they are in is weak
and more sandy than anything.

Production is disappointing and not anywhere like that of similar sized
trees that I've seen.

Did it set a decent number of fruit or too many small ones?

Would a mulch of manure around each tree help? Is this a good time to do it?

Yes, but not too deep and the chances are you really want to give them a
high potash feed like wood ash or slow nitrogen blood fish and bone.

I have read on the web not to add manure because it'll not encourage the
roots to go on the search for food. I can see the logic of this for new
trees but mine are a few years old.

Any views?

Too much nitrogen encourages soft growth. Potash encourages flowering
and fruit production. Don't mulch too deep either - many trees resent
having their surface aerobic roots buried too deeply. RHS advice here@

https://www.rhs.org.uk/advice/profile?PID=539

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Regards,
Martin Brown