Mystery of Blueberry Pollination Revealed
Rabbiteye blueberry hybrid cultivars were obtained by crossing outstanding selected seedlings from the wild river banks of South Georgia and North Florida. When blueberry plants fruit in the wild, state, each plant is a unique seedling that is cross pollinated by adjoining wild blueberry plants. This phenomenon has also been observed in low bush blueberry plants and high hush blueberry plants in the more Northern States, where commercial blueberry production was first introduced from harvesting wild fields of blueberry seedling bushes that the famous berry authority, Professor Darrow, astutely noted populations of millions of low bush blueberry seedlings meant there would be absolute and certain cross pollination, since they were all distinctly different genetically from one another. This concept is complicated and mysteriously known as 'Pseudocultivar, in Situ'.
In the wild and natural state, Rabbiteye blueberry plants are seedlings, each plant being genetically different from each other surrounding neighbor plant, and therefore, is easily cross pollinated to form berries. The new hybrid Rabbiteye blueberry plants that have been released by the USDA with cultivar names different from each other were distributed to commercial growers by vegetative propagating each plant, so that each named cultivar would reliably flower with predictable flowering time, harvest time, and data was obtained that demonstrated the value of growing that particular cultivar for commercial purposes.
It is well known that in areas outside the South, where many wild Rabbiteye blueberry plants grow near commercial plantings, two separate cultivars must be planted, if a grower expects to produce blueberries. In the South it is also necessary to plant two separate cultivars of neighboring Rabbiteye blueberry plants, unless wild native plants are growing nearby.
The flower of the Rabbiteye blueberry plant is shaped like a bell that hangs downward and this, unlike raspberry and blackberry flowers that face upwards, makes it difficult for honeybee pollination to happen. Most Rabbiteye blueberry pollination is done by solitary bees such as the bumble bee that lands upwards on the down-turned flowers and the bee slices into the nectar sacs - consuming the sweet nectar of the flower. This type of pollination is called "Buzz Pollination," meaning that the heavy weight of the bumble bee body and rapid wing movements will vibrate the berry flower, violently fanning and spreading layers of pollen from the male stamen flower parts onto the ripening receptive female pistol part. That insures Rabbiteye blueberry pollen transfer formation from the legs of the bumblebee that has presumably recently visited another different cultivar different from the visited flower landed upon.
There are no major pests or diseases of Rabbiteye Blueberries, but it is very important to plant them in an acid soil between pH of 4 and 5, and a use of 50% peat moss in the planting soil that will fulfill an important requirement. If the pH of the soil rises higher than 5.5, the blueberry plant will die.
Southern high bush blueberry plants are hybrid cultivar crosses of Rabbiteye blueberry and Northern High bush blueberry plants and can be grown in some areas of Florida, however, in most of Georgia, Northward and Westward production, will suffer some years from late frosts that kill early blueberry flowers or the early forming juvenile blueberries. Many commercial blueberry growers extensively experimented with plantings of Southern high bush blueberry cultivars, because of the promise of a very early crop of blueberries that demanded high prices in May, before the market downslide began when Rabbiteye blueberries flooded the market into an unprofitable chaos. Since that finding the commercial plantings of Southern High bush plants has decreased drastically after late spring frosts, sometimes devastated crops.
Remember, that it is crucial that no insecticides should be used during berry flowering, because solitary bee pollinators and bumble bees will be killed, leading to a blueberry crop failure.