Home Environment Encyclopedia of Cultivated Plants: From Acacia to Zinnia
A perennial shrub, blueberry is a member of the Ericaceae family and Vaccinium genus. Among the types of blueberry are the important lowbush, highbush, and rabbiteye. Of these three, the most important commercially is highbush, which is divided into northern and southern cultivars. Lowbush differentiates from highbush by being the shorter of the two. One cup of blueberries contains only 93 calories. Blueberry is rich in fiber, potassium, manganese, copper, iron, and zinc. The antioxidant and flavanoids in blueberry may protect one against cancer, aging, degenerative ailments, and infection. In small amounts, blueberry contains vitamins A, C, and E. Among its B vitamins are niacin, folic acid, pyridoxine, vitamin B6, riboflavin, and pantothenic acid. The chlorogenic acid in blueberry may reduce the amount of sugar in the blood, aiding diabetics.
One writer refers to lowbush blueberries as wild, but this designation obscures the fact that they are cultivated. Lowbush blueberries were likely the type that Native Americans harvested, though they may not have cultivated them, before the advent of Europeans. Amerindians ate blueberries fresh, dried, and in preserves, cornbread, and porridge. In the 17th century, New Englanders bought blueberries from Native Americans, making them into gruel and pudding, substituting them for cherries and currants. European settlers combined blueberries with flour, milk, and eggs. When colonists added blueberries to cornmeal, they called the product Indian fruit pudding. Colonists made blueberry pie with brown sugar.
Native Americans burned blueberry fields to kill shrubs and trees that encroached on them. This method of clearing land was not entirely deleterious because blueberries thrived on the charred soil. Without the cover of trees, however, the wind blew snow off the land, exposing blueberry bushes to winter injury. In the 19th century, those farmers who grew blueberries commonly burned one- third of their land each year. In the late fall or early winter, the grower mowed or burned blueberry land to kill pests and pathogens. A burned area will not bear fruit the following year.
In the 1860s, Americans began to can the lowbush harvest to extend its shelf life. The availability of canned blueberries stoked demand. By the 1920s, Maine had emerged as the leading canner. In 1926, Maine canned 70 percent of the U.S. harvest. The Great Depression forced growers to sell blueberries fresh because consumers could not afford the price of processed berries. Since World War II, freezing has replaced canning as the method of preserving blueberries. The consumer may store frozen blueberries two years.
In the 1980s, the yield of lowbush and other types of blueberry increased with the application of the herbicide Velpar, available in Canada in 1982 and the United States in 1983. Farmers apply herbicide in spring and fertilizer before the bush resumes growth in April. Given the requirement of nutrient-poor soil, the application of fertilizer must be infrequent. In May, the grower rents beehives to hasten pollination. The grower must guard against bear, fox, raccoon, robin, thrush, and grouse, all of which plunder the crop. Since the 1980s, farmers have harvested lowbush blueberries by machine. Less than 1 percent of the lowbush harvest is sold fresh. Most of the fresh crop goes to local hotels and restaurants. Most of the rest is frozen with a small portion being canned. Since the 1920s, the United States has exported lowbush blueberries to the Unied Kingdom. Since 1990, Germany and Japan have emerged as lowbush importers. Notable cultivars include Russell, which U.S. Department of Agriculture (USDA) scientist Frederick Coville bred in 1909, and Augusta, Brunswick, and Chignato, which the Kentville Research Station in Nova Scotia released in 1978.
There are two species of lowbush blueberry: Vaccinium augustifolium and Vaccinium myrtilloides. The first is more numerous in North America. A dwarf shrub, lowbush blueberry, like other types of blueberry, needs acidic soil, with a pH between 2.8 and 6. The soil may be peat or sand and, contrary to expectations and as we have seen, must be nutrient poor. Flowers, which may be white or pink, develop in May. Berries, ripening in late July in southern Maine and late September in Newfoundland, are one-eighth to one-half of an inch in diameter. Farmers cultivate lowbush blueberry from New Hampshire to northeastern Maine, and in New Brunswick, Nova Scotia, Prince Edward Island, northern Michigan, Minnesota, Wisconsin, and West Virginia. Vaccinium myrtilloides is grown in the Appalachian Mountains north to Labrador. Flowers, smaller than those of Vaccinium augustifolium, are white or pink. Berries are one-quarter to one-third of an inch in diameter.
Highbush and Rabbiteye
The hardiest blueberry, northern highbush grows 4 to 12 feet tall. It needs 750 hours of temperatures below 45°F to initiate dormancy. Berries, being between one-eighth and three-quarters of an inch in diameter, ripen over six to eight weeks. Whereas a green berry has 7 percent sugar, a ripe one has 15 percent sugar. Berries at the top of a bush, receiving the most sun, ripen first. Berries at the top of a bush have the most sugar and are largest.
In the 1890s, the attempt to grow northern highbush blueberries failed, probably because farmers did not appreciate that the soil must be acidic and poor. In the early 20th century, private growers and the USDA promoted the cultivation of blueberries, highbush and lowbush alike. In 1908, Frederick Coville bred the northern highbush variety Brooks. The next year he demonstrated that northern highbush berries, like all blueberries, need acidic soil. In the early 20th century, Coville bred six varieties: Adams, Dunphy, Grover, Harding, Rubel, and Sam. Farmers grew these cultivars in North Carolina, Michigan, Washington, Oregon, New England, New York, New Jersey, Connecticut, and British Columbia. Highbush was a lucrative crop. Expanding his work, Coville crossed northern highbush and lowbush cultivars, deriving the hybrids Pioneer, Katherine, and
Cabot. These hybrids grew no taller than four feet, yielded abundantly, and matured early. In the 1920s, Coville derived the varieties Concord, Greenfield, Jersey, and Ramcocas, and in the 1930s Catawba, Dixi, June, Redskin, Scammell, Stanley, Waraham, and Weymouth. Among these, Jersey is still grown in Michigan.
In the United States, Italian immigrants tried to grow peaches and grapes as they had in Italy, but because the climate and soil did not favor these crops, they turned to northern highbush. Before World War II, New Jersey was the leading northern highbush producer. After the war, Michigan overtook New Jersey. North Carolina, Washington, D.C., and British Columbia maintain large plantings of northern highbush. In the 1990s, Oregon emerged as a large producer.
The Netherlands may have been the first European country to plant northern highbush, in 1923. Poland began growing northern highbush in 1924, though the initial planting perished in the severe winter of 1929. After 1929, German scientist Walter Heerman bred the varieties Blauweiss-Goldtraube, Blauweiss- Zukertraube, Heerman, Pekord, Ama, and Gretha. Today, Germany, with more than 1,500 acres of northern highbush, has the largest acreage in Europe. In addition to the Netherlands and Germany, France, Spain, Portugal, Romania, and Denmark produce northern highbush. The Japanese, large consumers of blueberries, prefer northern highbush to other types. In the Southern Hemisphere Australia, New Zealand, Chile, and South Africa grow northern highbush. These ripen between December and April, supplying the Northern Hemisphere with fresh blueberries out of season. Since 1950, New Zealand has grown northern highbush and rabbiteye and exports to Japan. In 2000, New Zealand emerged as an exporter of northern highbush. In 1969, Australia first planted blueberries from U.S. seeds. Farmers grew northern highbush in Victoria and Tasmania and southern highbush and rabbiteye in New South Wales. Corindi, where the harvest is year-round, produces the majority of Australia’s crop. Australia exports to Europe, the United States, and Asia, especially Japan. In 2000, Chile exported northern highbush blueberries to 26 countries including the United States, Canada, Japan, the Netherlands, the United Kingdom, Italy, and Germany.
Farmers grow southern highbush and rabbiteye where the climate is too warm for northern highbush. Rabbiteye, being of the species Vaccinium ashei, needs 400 to 500 hours of temperatures below 45°F to initiate dormancy. Southern highbush needs 400 to 660 hours of temperatures below 45°F. Farmers grow rabbiteye and southern highbush from central Florida to eastern North Carolina and from northern Arkansas to eastern Texas. Florida has grown rabbiteye since 1892. In 1926, the University of Georgia began research to derive new varieties of rabbiteye and southern highbush. In 1939, the North Carolina Agricultural Experiment Station and the USDA joined this effort, releasing Calloway and Coastal in 1949, Homebell in 1955, Briteblue, Delite, and Southland in 1969, and Bluebelle in 1974. In a separate breeding program, the University of
Florida had derived varieties of southern highbush suitable for the United States and Australia.
Eck, Paul. Blueberry Science. New Brunswick, NJ: Rutgers University Press, 1988. Eck, Paul, and Norman F. Childers, eds. Blueberry Culture. New Brunswick, NJ: Rutgers University Press, 1966.
Scott, D. H., A. D. Draper, and George M. Darrow. Commercial Blueberry Growing. Washington, D.C.: U.S. Department of Agriculture, 1978.
Sumner, Judith. American Household Botany: A History of Useful Plants, 1620-1900. Portland, OR: Timber Press, 2004.
Trehane, Jennifer. Blueberries, Cranberries and Other Vacciniums. Portland, OR: Timber Press, 2004.
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