Since the first rentals for apples, made about 1910, the scope and complexity of pollination requirements have increased every year. Thousands of colonies are rented in Ohio each year.
Following are some of the crops that need bee pollination:
Apples and Pears: Because most fruit trees are propagated by grafts, a solid block of one variety is genetically only one plant. Most varieties are self-sterile, and therefore cannot be productive without pollen from a compatible variety. This is accomplished by the grower interplanting compatible varieties, providing bouquets of flowers from other varieties, or supplying the beekeeper with pollen to use in pollen inserts.
Apples require 1 colony per acre. Pears often need 2 colonies per acre, due to the low sugar content of the nectar. Colonies should be spaced in groups of 15 to 20 colonies for every 15 to 20 acres. This provides for a 300 to 350 yard space between groups, which normally gives the highest fruit yield at minimum moving of bees by the beekeeper.
Other Tree Fruit: All varieties of sweet cherries and many varieties of European plums, grapes, apricots, and peaches need no cross pollination, but they still need bees to move pollen to the stigma. One colony per acre is usually sufficient.