Q What is plum pocket?
A It is considered a rare fungal disease of plums, though many of our readers have reported attacks on plums and cherry plums in recent years.
Caption: Plum pocket can play havoc with a plum crop
Q How do I recognise plum pocket?
A Look out for long and narrow, crooked or lopsided fruits. To begin with, the fruits look pale green and smooth on the outside. When cut open they are pocket-like, with an empty space where the stone should be. The fruit goes on to develop a spore layer on the skin, which gives it a mealy, creamy-grey covering. It becomes wrinkled and may swell, becoming spongy inside. The fruit shrivels and falls prematurely. The twigs are also affected.
Q What causes plum pocket?
A It's caused by a fungus, Taphrina pruni, related to the fungus that causes peach leaf curl. The fungus spends the winter in infected shoots and old fruits and is spread to new leaves by spores borne on air currents and in splashes from rain.
Q How can I prevent plum pocket?
A Collect and burn or consign to the bin all affected fruit to reduce the level of infection next year. If you see any diseased twigs, cut these out too. The good news is that the disease is unlikely to affect the whole crop at once, and may not recur again for several years.