Many of these are sports, or accidental mutations of another variety. Others, especially the more recent introductions, are the result of painstaking crossing and selection by apple breeders. Each parent plant supplies half the heritage of seedlings, but that half may be a set of characteristics either partly or completely hidden in the parent.
The seedlings are an unknown mixture until the breeders grow them to fruiting size to see what characteristics they have. This work takes time, and many seedlings prove to be inferior to their parents.
Sports, or mutations, may occur at any time, often without apparent reason: Suddenly a branch of a tree is different. Occasionally the odd branch results from mechanical damage, such as pruning; sometimes experimenters purposely change genetic structure with chemicals or radiation. Most sports are worthless, but now and the turns to have a characteristics that make it worth propagating to create a new strain.
'Delicious', which is by far the most popular and economically important apple in America, first sprouted in an Iowa orchard in 1872. Its parentage is uncertain, but one parent may have been a nearby 'Yellow Bellflower' apple. That 'Delicious' exist at all today s almost a miracle. The owner, Jesse Hiatt, cut the seeding down twice, but it re-sprouted each time, so finally he let it grow. In about 1880 it bore fruit that Hiatt thought was the best he'd ever tasted. The name 'Delicious' was given at a fruit show by C.M. Stark of Stark Nurseries. Stark didn't learn the name of the grower until 1894, and by then the apple had already begun its rise to fame.
'Delicious' has produced a number of sports, including the original red sport, 'Starking'; the redder 'Richard', 'Royal Red', 'Hi Early', 'Chelan Red', and 'Red Queen'; and the spur-type 'Starkrimson', 'Redspur', 'Wellspur', 'Hardispur', and 'Oregon Spur'. 'Delicious' is also a parent of 'Melrose'.
The first seedling of 'Jonathan' sprouted in Woodstock, New York, apparently from the fruit of an 'Esopus Spitzenburg'. A Judge Buel of Albany found the apple so good that he presented specimens to the Massachusetts Horticultural Society, naming it for the man who first showed it to him. 'Jonathan' was the most important commercial variety before 'Delicious' took over.
Red sports of 'Jonthan' include 'Jon-A-Red' and 'Jonnee'. Hybrid descendants include 'Joagold', 'Jonamac', 'Idared', 'Melrose', 'Minjon', and 'Monroe'.
The 'McIntosh' apple came from the McIntosh Nursery in Ontario,Canada. John McIntosh discovered it about 1811 but did not propagate grafted stock until 1835, when the grafting technique was perfected. Well know descendants of 'McIntosh' include 'Summerred', 'Niagara', 'Early McIntosh', 'Puritan', 'Tydeman's Red', 'Jonamac', 'Macoun', 'Empire', 'Cortland', 'Spartan', and the spur variety 'Maespur'.
Other apples with long lines of descendants include 'Rome', 'Golden Delicious', 'Northern Spy', and 'Winesap'.
The extensive work on dwarfing rootstocks for apples has produced plants sizes ranging from a 4-foot bush to a 30 foot spreading tree. There is even a true, or genetic, dwarf that stays small on any rootstock.
Spur-type apple varieties are sports of standard varieties. They grow more slowly than other plants, and their spurs are packed closer together on the branch. This less vigoroues growth means that they are kind of genetic dwarf, but they are still good sized trees unless grafted to dwarfing roots. Spur varieties are difficult to train formally. If you buy spur varietes on dwarfing roots, use a training method that doesn't call for any particular form.
Prunning methods depend on how grow the tree.
Thinning is crucial with apple varieties. If left alone the trees set too much fruit, and the heavy crop can snap branches. EVen more important, many apples varieties tend to bear every other year. If you leave too much fruit you encourage this alternate bearing : The following year you may find that your trees bears only a handful of apples because the large crop of the previous year has depleted the tree's reserves. Most important of all, the quality of the remaining fruit is better after thinning.
There are many thinning methods, but the best method is to make a light first thinning by the time the fruit is pea size. After this, wait for the natural drop of young fruit in June, then thin the remaining fruit so that there is a single apple every 6 inches along the branches. Each spur may have a cluster fruit. A single fruit is less likely to become diseased, so leave only the largest fruit on each spur.
Thin carefully or you will damage the spurs or even pull them off the young fruit. If the apples are small one year, thin more heavily the next year. If the fruit set is light but the fruit is large, thin less the next season.
Most apples are self-infertile, so for a good crop most varieties need a pollinator.
Almost any two kinds that bloom together offer good cross-pollination. The following varieties produce poor pollen so cannot pollinate other varieties: 'Jonagold', 'Spigold', 'Mutsu', 'Gravestein', 'Winesap', 'Stayman', and 'Stayman' sports such as 'Blaxstayman' and 'Staymared'. If you plant one of these varieties, you will need to plant three different varieties in total to get fruit from all of them. Also, if you plant only a very early and very late variety, they will not cross-pollinate.
All apples need some cool winter weather, but there is an enormous range in this requirement, so varieties are available for any climate except for tropical and low desert regions.
Apples are subject to attack by many organisms, but the gardener will have most trouble with codling moth and other fruit-spoiling pests and the usual aphids, mites and scales. A regular spray schedule is best. Repeated sprays can control diseases such as mildew.
