How ever, many varieties cannot produce fruit from their own pollen. If the male pollen is shed before the female flower is receptive, fruit-set becomes a problem. Some species of fruit trees do not fit conveniently into either category. Pistachios have male trees that produce pollen and female trees that produce fruit. To grow them successfully, it is necessary to plant at least one male tree for every eight female pistachio trees.
Most apple trees are self unfruitful.
Golden Delicious', a self fruitful variety, and 'Jonathan' are the most common pollinators used. In general, a pollinator should be considered for all pear varieties, even though 'Kieffer' and 'Duchess' set good crops without pollinators. Most peach varieties are self fruitful. However, if you are planting 'J. H. Hale', 'Stark Honeydew Hale', or 'Stark Hale Berta Giant', you need to plant another variety to assure adequate pollination. The lack of fuzz on the fruit is the main difference between a nectarine and a peach.