The apple flavour spectrum extends from sharp acidity in culinary varieties to sweetness in dessert varieties; the best flavoured dessert apples combine a subtle blend of both — about 0.5 per cent acidity with a high sugar content. The flesh of some apples is highly aromatic; some are dry fleshed, others exceedingly juicy. The colour range is great and there are a number of excep-tions to the assumption that dessert apples are red, cookers green.
- Apples can be grown in most places at any altitude below 600 feet, provided frost-laden air can drain away to a lower level. A mean annual rainfall of 20-30 inches of rain is desirable.
- Every variety is self-incompatible to a certain degree; some are completely self-sterile, others can set a worthwhile crop alone. However, the cropping of all vari-eties is improved if cross pollination occurs. Varieties are classified into two categories, diploid and triploid, according to their chromosome complement. Tri-ploids have little or no good pollen and must be interplanted with two diploid varieties flowering simultaneously — the diploids pollinating each other and, mutually, the unresponsive triploid. Cross pollination is effective between any two diploid varieties whose blossom period overlaps.
- Most varieties bear their fruit mainly on spurs formed on the older branches. The tip bearers do so on the tips of one-year-old shoots. Some sorts fruit on both kinds of wood.
- Dwarf trees permit spraying, pruning and harvesting to be done without the need for step-ladders; they are also more easily protected from bird damage.
- A number of small trees in a range of varieties covering a long season is preferable to a few large trees each giving an excessive quantity of fruit at one season and with one flavour. On average, a cordon tree gives 3-5 pounds of apples, pyramids 6-8 pounds, bush trees on Malling IX rootstock 25-30 pounds, bush trees on Malling II 80-100 pounds, and larger trees according to size.
- Alternatively, a ‘family’ tree having several varieties grafted on the one trunk can be grown or additional varieties be grafted on to an established tree which is yielding glut crops.
- Apple trees have a long expectation of life and may remain fruitful and healthy for 50 years or more.
Apples prefer deep loams but can be grown on sandy soils and heavy clays, if care is taken to drain wet soils and irrigate dry ones.
Cordons (planted 2 ½ feet by 6 feet), espaliers (10-18 feet apart), and arcure trained trees (3 feet by 6 feet), are grown against walls, fences or on post and wire supports; dwarf pyramids (3 feet by 7 feet), spindle bushes (6 feet by 13 feet), pillars (5-6 feet by 10 feet), bush (12 feet by 12 feet), and half-standards (15-18 feet by 15-18 feet), on an open, but sheltered, site. Provide wind-breaks if natural shelter is not present.
Plant in November, if possible, or up to the end of March whenever the soil is sufficiently friable. It is best not to incor-porate farmyard manure before planting into any except the poorest of soils. Plant as firmly as possible, ramming the soil round the roots with the square end of a stout post, and tie the tree to a sub-stantial stake. Mulch the root area to conserve moisture in the soil during the first season, thereby minimising the trans-planting check to growth.
Subsequently, control the vigour balance by applying farmyard manure annually as a mulch in the spring and fertilisers according to the tree’s needs.
Trained trees respond to being summer pruned in July or August, the side shoots being shortened to five leaves, the leaders remaining unpruned. Winter pruning con-sists of shortening summer-pruned shoots to two buds and reducing the lengths of the leaders by a third. Bush and half-standard trees are not summer pruned : in winter, the dead and crossing shoots are cut out and also sufficient branches to keep the head of the tree to an open habit. The leaders are shortened by a third for the first four years only —leaving them un-pruned from then onwards induces the branches to droop and become more fruitful.
Vigorous but unfruitful trees can be shocked into fruiting by bark ringing the trunks in May or by root pruning in October or November (see Pruning). Putt-ing the soil down to a mixture of fine grass and clover, which is kept cut short, retards tree growth and induces fruitful-ness. In addition, dessert apples take on a better colour when grown in grass than under clean cultivation and have a longer storage life.
Pests And Diseases Of Apples
The chief pests and diseases of apples are : aphids, apple blossom weevil, sawfly, sucker, capsid, various caterpillars, cod-ling moth, red spider mite, woolly aphid, mildew, scab, brown rot, canker, collar rot, gloeosporium storage rot, black rot, silver leaf, and the viruses star crack, flat limb, chat fruit, rubbery wood and mosaic. The physiological disorders of bitter pit and russeting may be trouble-some under some conditions. Birds may attack apple trees at various times — ravaging the fruit buds, destroying the blossom and pecking holes in the fruit.
Many varieties set an excessive number of fruitlets and hand thinning is necessary if the apples are to grow to a worthwhile size. Many fruitlets fall naturally during the ‘June drop’ but additional thinning is necessary in June and July. Each cluster of dessert fruit must be reduced to two fruitlets, always removing the largest one —the ‘king’ fruit—first, and the clusters reduced to at least 3 inches apart. Thin cookers to single fruits 6-8 inches apart.
Apples are ready for harvesting when well coloured, with the seeds becoming brown in colour, and when they part readily from the fruit spurs.
Some varieties set no fruit at all when :,elf-pollinated, while others under favourable conditions set a fair crop. Yields are better when there are enough varieties for cross-pollination. There are a number of popular varieties which are poor pollinators (triploid varieties) but most are diploid, which pollinate each other very well. It is important to have at least two diploid varieties in a collection, unless the pollinator chosen is sufficiently self-fertile alone. When choos-ing varieties select those which will flower about the same time or overlap by a few days with others. There is some variation in the flowering periods of varieties but on the whole the times are very consistent. Winter temperatures and district can affect flowering periods.
Pruning of apples
- Most apple trees are purchased when they are 1-4 years old. Trees older than this will need special care to help them over the shock of transplanting. A good nurseryman ensures that the trees he sends out have healthy strong roots, properly spaced for the type of tree which is to be grown—bush, cordon, pyramid or any other shape.
- The gardener who wishes to train his own trees will plant maidens. These are one-year-old trees with a single stem, possibly with a few sideshoots, called feathers. This is the cheapest way of buying a tree. There is no reason why the first pruning should not be done in the winter of planting and this is a time to decide what type of tree should be grown. A selection can be made from the following.
- A standard tree is one with a 6 foot long stem. These are not suitable for gardens as they make large trees, which are difficult to manage. They can, however, make pleasant shade trees. The early treatment of the standard tree consists in pruning the maiden after planting, removing half to one-third of its length to encourage a further upright shoot to form a main stem at 6 feet.
- The tree should, at one year after planting, be tall enough to prune this main stem so that the lowest branch is at the right height from ground level.
- Pruning thereafter may consist simply of the removal of overcrowding branches with the occasional pruning of the ends of the leading shoots to help to form new Growth.
- Spurs, which are shoots with a number of fruit buds, can be reduced in size, since too many fruit buds can be as embarrassing as too few.
- The half-standard tree has a main stem of 41-5 feet. It is more manageable than a standard tree in the early years, but varieties on a vigorous stock still make big heads with delayed cropping. Most varieties will grow and crop happily with the minimum of pruning even on medium vigorous rootstocks which usually en-courage earlier cropping-6-8 years from planting.
Large bush trees growing about 15-18 feet high, are popular in large gardens. The main stem is 2-I-3 feet long. The lowest branches make cropping underneath dif-ficult except for grass. The trees can be managed fairly easily from ground level. Pruning starts with the maiden which is pruned at a point 3-3 ½ feet from ground level. As a result of this pruning a number of shoots, possibly three to five, will grow from the buds below the pruning cut in the following summer. The shoot from the top-most bud (the leader) should be fairly upright, while the remainder become less upright the lower down the stem they are. Dwarfing bushes are very popular in the garden. Varieties grafted or budded on semi-dwarfing rootstocks need not exceed 7 feet in height. A number of varieties on these stocks can be even smaller. At their heights the trees are easy to manage and can be planted fairly close together. Pyramid shaped trees are also small bushes on dwarfing or semi-dwarfing stocks. They are very useful in small gardens as they can be kept compact. The maiden tree is pruned to within 18 inches from ground level after planting.
In the following winter each new leader is pruned to 10 inches, depending on vigour, above the cut made in the previous winter.
The direction of the top bud at each cut should be varied so that an upright main stem is made. When this reaches about 7 feet high—and this may take many years, if ever —the top can be removed in mid summer to restrict new growth.
Any branch which is rather upright should be tied to a near horizontal posi-tion. This should have the effect of restricting growth and encouraging fruit buds to form.