Prunus Shot Hole

This year there seems to be a large amount of ‘Prunus Shot Hole’ (Wilsonomyces carpophilus) about. This can affect any of the Prunus species plums, cherries and peach plants, but mine seem to on Almonds. It is a bacterium that overwinters on the bark and in leaf litter also in the bud, spores being spread by drops of water splashing on the leaves. If you look closely you can see small areas of the leaf that go brown and then that brown area drops off the leaf. This gives  the impression that the leaf has been eaten by an insect. The disease can be severe  during warm wet winters and wet springs. It can be controlled by using copper based fungicide during the winter months.