Allotments 4 All

Yellow blotches have suddenly appeared on the leaves of my 4 year old plum tree. Any idea what it my be?

hi
had a quick look in the "Fruit Expert" book by Dr D.G.Hessayon but couldn't see anything conclusive,you may have to let the problem go a bit longer for the signs to be more obvious.sorry i couldn't be more helpful.
all the best flutemaster

Could it be just the natural ageing of the leaves?  ::)  Cheers,   Tony.

The lack of rain this year especially in the south of England may lead to poor uptake of nutrients by the tree and cause mild chlorosis (yellowing) of the leaves.
You say it is a 4 year old tree, that's still pretty young and the roots try and do most of their growing in spring - we've had 2 dry springs here and that's bound to affect it.
I'm assuming that it's planted in the ground, not a pot, and that you didn't get much rain where you are, and that the plum tree isn't in a waterlogged position, so at a rough guess, you'd need to be giving it about 4 large watering cans a week at the minimum.