Bladder plum is a fungal disease similar to peach leaf curl. In cool wet spring weather it spread by rain splash and infects fruit making them spongy and rotten.
Identify the problem
Bladder plum infection starts with a small blister on the fruit. The blister quickly grows and soon covers the whole fruit and they may grow to ten times their normal size. The fruit goes white/grey, gets a spongy texture and becomes covered with velvety, gray fungal spores. Eventually infected fruit dry out and turn black.
- Prune and dispose of affected parts of the plum tree.
- Spray with copper oxychloride spray.
- If irrigating trees apply water to the roots and not foliage.
- Carry out a winter spray programme when trees are dormant.