Caring for Apple Trees
How to Thin Apple Tree Crops
Bearing a heavy crop puts a strain upon a tree that might result in a harvest of poor-quality fruits.
Start to thin a heavy crop in early June, before the natural drop that occurs later in the month.
Use a pair of scissors to cut through the stalk, or hold the stalk between two fingers and press the apple away with the thumb.
First remove badly shaped fruits, then wait until after the natural drop before making a final thinning.
Heavy thinning is seldom necessary on cordons, espaliers and dwarf trees. On large bush trees, however, the fruit should be spaced_ out. Thin dessert varieties 4-6 in. (100-150 mm) apart, and large cooking varieties 6-9 in. (150 230 mm) apart.
All cooking and most dessert varieties can be reduced to singles, but some dessert varieties, such as ‘Ellison’s Orange’, grow very large if left as singles.
At the second thinning remove blemished and mis-shapen fruits and also the large king, or crown, apple which grows in the centre.
However, the fruits on some varieties, such as ‘Golden Delicious’, grow on long stalks, and the king apple retains its shape. In this case it need not be cut out.
Pests and diseases
Aphids, grubs of the codling moth and caterpillars of the Winter moth are among the most troublesome pests, but apples may also be attacked by Apply sawfly, Capsid bugs, Fruit tree red spider mites, Tortrix moths and Woolly aphid.
The chief diseases and disorders are Apple canker, Bitter pit, Brown rot, Fire blight, Honey fungus, Magnesium deficiency, Papery bark, Powdery mildew, Scab and Silver leaf.
To test whether an apple is ready for picking, place the palm of your hand beneath it and give a simultaneous lift and gentle twist. It should part easily from the spur.
Eat early varieties as soon as possible after picking, as they will not keep more than a few weeks.
Handle carefully later varieties intended for storing.
Keep the apples in a frost-proof garage or spare room where the temperature is stable but cool.
The apples can be wrapped in specially oiled paper, stacked on fibre trays or kept in clear, plastic bags with the tops unsealed or the sides perforated.
Spraying programme for apple trees
It is important to use the correct sprays at the right time to control the various pests and diseases that ruin fruits and affect the size of the apple crop. The timing is based mainly on the stage of bud development.
A systematic spraying programme will deal with the most common pests and diseases, while other, rarer, outbreaks can be dealt with if and when they should occur.
Do not spray when the blossom is fully open, as this is when bees and other pollinating insects are most active.
Over-spraying can do more harm than good by killing beneficial insects; so keep to the spraying programme and follow the manufacturer’s instructions.
Every third year in the dormant period, between December and February, apply tar-oil wash to control aphids, scale insects and apple suckers.
If groups of minute, red eggs of the fruit tree red spider are numerous, spray with DNOC-petroleum wash in February.
The main spraying programme begins at bud-burst in March and continues, with only a break when the blossom is fully open — and pollination is taking place – until about the middle of July.