Diseases in apple trees – ruthless action is the key


There are diseases and pests affecting apple trees that are dreaded by gardeners.


After waiting months, from spring blossom to seeing the fruit ripen, it is so disappointing to see pock-marked or even completely rotten fruit.


It seems apple trees are prone to a depressing catalogue of problems which causes damaged, rotten, infected and most importantly, uneatable apples.


The key to healthy apple trees is prevention and prevention consists of cleanliness and urgent action.


If there’s a problem, identify it and do something about it. Often the best thing is to sacrifice a crop from a diseased tree for one season in the hope of curing it for the next.


So be decisive, remove and burn any fruit which shows signs of disease, regularly sweep up and burn fallen leaves, and keep any storage area clean with an annual wash of soda and warm water.


So here are some of the most common diseases and pests and how to deal with them.


Beware the rotten apple….Brown Rot


This is a common sight on garden apple trees and often it is caused by the wild birds we feed. Fungus enters through pecking by birds and it turns the fruit brown and soft. Eventually the fruit becomes covered with rings of white mould which spread rapidly.


Brown rot is a fungal disease causing a brown, spreading rot in fruit. It is caused by the same fungi that cause blossom wilt of the flowers and fruit spurs


There’s no control, so all you can do is to keep looking at the


tree and pick off any that you see looking like this and throw them away immediately before the rest of the apples are affected. Store only perfect fruit.


Scab


Spray when the blossom is still in tight bud form, and then when they have opened to show some pink on the petals, then spray again when the petals have fallen. About three weeks later spray for the fourth and final time.


Canker


Canker shows up as sunken patches on the bark with white fungus growths in summer. The stem swells round the wound,


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Winter moth – likely to cause havoc if it arrives


Apple canker – a fungal disease causing sunken patches of dead bark on the branches of apple trees. Infections often begin at wounds or buds


usually but if it spreads right round the branch it will cause the branch to die.


Cut out diseased branches or, if the branches are large, cut out the canker and destroy the diseased wood.


And some pests, starting with the codling moth


You can get to this pest, the most serious to affect apple trees, by killing the males before they fertilise the females. Set up a sticky trap in your fruit trees (one trap is enough for five trees) with a capsule of the female sex pheromone. The males will stick to the pad, reducing the number of fertile females by about 80 per cent. The same control can be applied to plum sawfly.


Codling moths have caterpillars that look like maggots and these little creatures tunnel into the growing fruits and feed inside them. They leave a powdery, brown ‘frass’ on the outside and are found inside as well. Spray with permethrin three weeks after the petals fall and again three weeks later.


Winter moth


This is a common enemy of fruit trees. Put sticky grease bands round the tree about half way up the trunk, or apply grease with a special spray gun, to stop the moths from crawling up the tree in early autumn to lay their eggs.


You can spray with permethrin when the flower buds are formed but still green.


Apple sawfly


The larvae burrow into the fruit after feeding on the surface. You will see ribbon-like scars across the skin. Spray with permethrin about a week after the blossom has fallen, soaking the young fruits. Also remember to pick up the apples that fall in the ‘June Drop’.


Country Gardener


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