Dwarf apple trees don't produce tiny fruit, nor are they regular-sized apple trees that have been magically shrunk. They are, in fact, any apple tree cultivar that has been grafted onto miniature or dwarfing rootstock.
There are many reasons why dwarf apples are so good. They are easier to spray and prune, and harvesting is much more efficient. It's also easier to protect them from birds and other animals that like to eat the buds and fruit. Plus, in a small garden, you can grow four or five dwarf apples to provide many months' supply of fruit in the same space as one normal-sized apple.
Most trees are made up of two parts: the rootstock, which is a dwarf, and the scion, which is the top or main part of the tree. Although it will never have the yield of a larger tree of the same variety, a dwarf apple will start fruiting much earlier, often in its second or third year.
Source: Gardening Australia
Photographed with: Olympus Pen EP-3, with Olympus M.Zuiko Digital ED 60mm f2.8 macro lens, with an exposure bracket of +/- 2 EV at f 8 and 200 ISO and the resultant images combined to produce an HDR image.
Dwarf Apple – Jürgen Strauss Photography