A small amount of trace elements might also help.
Jim

"DD" wrote in message
...
I have a lemon tree growing in a tub, it is about 10 years old and has
been recently repotted. It has fruited well this year but now the leaves
have started to go yellow. I am fairly sure that it is not lack of water
and it has always been kept well fertilised with Organic Life and
occasionally with Citrus food. Could anyone suggest what the problem
could be?

DD