This seems to be affecting my victoria plums. Will the whole crop be lost? Is there anything I can spray the tree with to stop it happening next year? (lost entire crop 2 years ago due to constant rain, no crop last year due to very late sharp frost)
It is worst in a wet summer and there have been a lot of downpours recently. There is no spray. Pick off affected fruits as soon as they are noticed and bury them.
Apply 70g sulphate of potash per square metre under the spread of the branches in March each year for three years to ‘harden’ the growth of the tree and help it to resist the fungus.