The number of apple varieties is over 6,500 in the World, in Turkey the number is about 460.
However, among these,there are very few in point of high quality, fruitfulness and commercial expansion.

The biggest cause of inadequacy in fruit pollination is the problem of fertilization even if that plenty of flowers in the apple orchards which has established with a single variety

Apple varieties are generally infertile.

It means that they can't fertilize with their own flower powder.
A different type of fertiliser surely needs pollens.
For this reason, a good kinds of mixture should be arranged while creating the orchard.
While making a mixture of varieties, it is necessary to know that which varieties fertilise the main variety.

Table of fertilizer types are given below.