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.