Pollinating Apples

Figure 1. Bumblebee on apple blossom (Alan R. Biggs, West Virginia University)

Apples require cross-pollination for optimal fruit set and size.  Cross-pollination involves the transfer of pollen from one apple cultivar to another by pollinating insects, such as bees which are referred to as pollinators.  The cultivar supplying the pollen is called the pollinizer.  For successful pollination to occur, bloom periods must overlap.  Triploids apple cultivars, such as ‘Mutsu’, ‘Jonagold’, and ‘Shizuka’, cannot supply viable pollen and are unsuitable as …

Parentage of Apple Cultivars


Nearly all apple cultivars have two parents – just like humans!  Apples have a genetic system that generally prohibits self-fertilization.  This self-incompatibility system is a way of insuring that each apple seed will be a hybrid between the maternal (seed) parent and a paternal (pollen) parent. The self-incompatibilty system is also the reason why two or more cultivars must be planted in an orchard to achieve fruit production through insect-vectored movement of pollen from one cultivar to the other.