Dave, Malcolm, Martin,

Thank you so much for the great guidance...

On Wednesday, October 25, 2017 at 9:13:40 AM UTC+1, Martin Brown wrote:

The main problem is the stuff is around the tree now so reinfection net
year is almost inevitable. Copper fungicide will slow it down.

Hmm.. that's helpful (albeit somewhat worrying). When should I spray the copper fungicide? (Now [Oct], or just before next Spring?) Alternatively, if I were to destroy the tree and plant a new one in its place, is it likely that the new one would become infected by the spores left behind by the old one? I'm hoping I can cure the existing tree, because I've put lots of time and effort into training it to a specific shape, to provide ideal shade over a certain sitting spot on my patio. So far, the disease has not spread to neigbouring fruit trees, but is there a danger this could happen? (I have apple trees, and another plum within a few meters of the infected plum tree.)

TIA,

Al