Cultivar (variety) selection is perhaps the most important aspect of starting a new commercial blueberry planting. There are numerous productive varieties available and more continually be released from public and private breeding programs. Blueberries have several different important characteristics such as yield, fruit size, color, firmness, flavor, scar strength, disease resistance, post harvest shelf-life, etc. that contribute to adaptation in a specific area. There is a tendency to assume that newer varieties are always better but in fact it is necessary to evaluate varieties old and new in specific growing conditions to determine those best adapted. There are many fine older varieties that often may fit specific production constraints well. And newer varieties may show weaknesses or shortcomings once they are propagated and grown on a large scale over an extended period. So growers continually evaluate new varieties as they come available and change varieties when needed, replacing reliable, productive older varieties slowly only after a staged trial process.
Variety Patents and Licensing.
Blueberry Plant Types.
Southern Highbush blueberry
The two types of blueberries that will produce reliably in mild climate growing areas are southern highbush (SHB) and rabbiteye types. The southern highbush types are generally preferable because they are earlier and have better horticultural fruit quality characteristics. Rabbiteye varieties are vigorous, tolerate higher soil pH and other stresses, and typically produce later in the season. So, while the emphasis for offseason production is clearly on southern highbush types, there eventually may be a role for selected rabbiteye varieties in certain situations depending on the target market.
There are many commercial SHB blueberry varieties available through nurseries. In many countries or geographical areas, newer varieties may be protected by plant patents and their propagation and distribution limited by licensing agreements.
The lower chill requirement, early producing SHB varieties are recommended for mild winter climates. Varieties shown to be promising in diverse mild climate growing areas include the following:
1/PVP - Plant variety protection indicates a patented variety. UFL indicates patent and licensing rights controlled by the University of Florida, Florida Foundation Seed Producers, PVP-UGA indicates patent and license rights controlled by the University of Georgia.
The harvest period varies with the growing area and across growing seasons depending upon chill hour accumulation and the heat unit accumulation during the period from February to May. The following graph illustrate the harvest period for selected varieties at coastal and southern California growing areas.
1/assuming frost free or frost protection Note: the recently released SHB varieties Abundance, Primadona, Sweet Crisp, Snowchaser, Spring High, Spring Wide, Rebel, Camellia, and Palmetto also appear to have ufficiently low chill requirement to be well adapted to coastal and southern California but information is not yet available on the harvest periods for these varieties.
Additional considerations.
Rabbiteye blueberry
Many growers are replacing Sharpblue and Misty with newer low chill varieties such as Emerald and Jewel, because Sharpblue tends to produce smaller fruit and has a reputation also for a leaky scar end. The Gulf Coast variety also has been replaced on many farms because while it is early, vigorous, and productive, a high percentage of the fruit retain their stems when picked and this requires additional labor to remove these stem pieces prior to shipping. The plant shape may also be an important consideration. More upright varieties such as Star require less pruning and this can reduce costs. Larger fruited varieties such as Emerald and Jewel may also reduce harvest costs and in some markets the larger fruit may be more desirable. But the larger size of fruit may also affect fruit firmness or flavor. Some varieties are more flexible with regard to harvest period – Saphire, Emerald, and Sharpblue, tend to flower multiple times during the year in mild climate zones and this may enable production during additional fall harvest windows.
