Help and advice, please.

This is a seemingly very sick apple tree in its first year.
Any advice or information would be appreciated, thanks.
The tree is espalliered against a sunny south west facing fence. It flowered well in spring and has sone fruit forming, but the leaves are shrivelled and curling and dry - and appear to be dying. The bark is conered with pin-head sized white spots.
I am at a loss. Perhaps I should cut it down and burn it. Any suggestions would be appreciated.
Cheers.. Jim