A quick gurgle of the net indicates that it may be a combination
of my soil and the sodden UK conditions causing iron deficiency.
Can anyone cast any better light?

The leaves have prominent veins (darker green), are slightly
curled up and are definitely chlorotic.

The only other match is a phycoplasma or similar nasty, which
I can do nothing about (except grub the tree).


Regards,
Nick Maclaren.

Try watering it with chelated iron. If the leaves don't start greening, then think again.