Q Last year a lot of our apples were affected by rough, hard patches on their skins. What caused it and how can I stop it from happening again this year? Sally Peters, Lincoln
A Blame scab disease (Venturia inaequalis). Causing fruits to develop cracks and corky swellings, and leaves to develop greenish-brown blotches, it’s only skin deep so your crop can be harvested and enjoyed. Overwintering as spores on twigs and bark, the fungus attacks maturing fruits and, in extreme cases, can badly disfigure them. Unfortunately, showery weather, when blooms are opening, favours infection.
Another point: some varieties, such as ‘Bramley’s Seedling’, are more prone to attack than others. No chemical sprays are recommend forwhen winter pruning. Another cause of rough brown patches which, in this instance, are slightly raised, is an attack of capsid bugs. Both nymphs and adults pierce tissue with thin and tubular stylets. Then, when feeding on sap, inject tissue with infected saliva which causes fruits to develop a rough brown curving ridge.
