too many leaves in too little space (plum tree)

The problem I have have is with a 5yr old Victoria plum tree in that every year as of now,the tree produces too many leaves for any one area.These leaves curl when grown as if infected with aphids etc,but there is no indication of any pest infestation?
Equally the fruits form obviously at first very small , then soon after just wither and drop?
I have another plum tree in the same area (20yds away) which thrives....any indication of problem with initial tree would be greatly appreciated.:cnfs:

 

Hi caskin,

Any chance of a few photos of the tree in question, including closeups of the leaves, bark and any fruits? It sounds to me like a fungal infection such as Monilinia laxa or Nectria galligena. Usually when the symptoms of fungal infections like this appear it is too late to do anything about it. As fungi spread via spores carried on the wind your other tree could be in line for being infected too. Keep an eye on both trees, post some pics and keep your fingers crossed!

Matthew.

 

Hi Many thanks fro answer I have tried a number of things,but I will attempt to upload some photos for you which should show the problem..Many thanks Derek

 

After some in depth discussion with my local garden centre I went back to the tress with a magnifying glass when the problem became extremly obvious as the leaves are packed with juvenile aphids.
Most treatments are for over winter sprays,but is here anything I can do now to hit the critters,remembering the tree is quite large?

 

As aphids breathe through their skin, a spray of soapy water (i.e. washing up liquid) can block their pores and cause the little green blighters to suffocate and die. Alternatively you could also try other methods of biological control as mentioned here: http://www.rhs.org.uk/advice/biocontrol.asp

Hope this helps,
Matthew