From this to this 

With clear blue skies and good blossom spring 2019 started so well for my plums. But then many things began to  go wrong. The first disaster was a snap frost that did for my Victoria blossom. Fortunately another variety of plum flowers a bit later, is better sheltered and survived unaffected by frost. That didn’t save the crop from the fungal attack of ‘brown rot’.

More on Plum Problems

• Plum fruit infected with Monilinia laxa have grey coloured pustules. This fungus can also be responsible for end of stem wilt.
• Plums infected with Monilinia fructigena have pustules that are buff coloured.
• It looks like I might be blessed with both fungal infections.
• Brown rot survives on mummified fruit and small cankers on the tree. It passes quickly on to other fruit in the cluster particularly in moist weather.
• There is no spray available to gardeners so I will have to improve my hygiene and collect up and burn or bury deeply all infected twigs and fruit.
• Unhappy with previous years crops I had invested in a new victoria plum tree  and I will hope for more success in years to come.