Potato

The high Andes Mountains were the first area of domestication for the potato, the most important root crop in the world. The potato supported many pre-Columbian Andean civilizations, culminating with the Incas. Originally cultivated as a cool-weather crop, it was an important contributor to the agricultural and industrial revolutions of Europe. Today, the potato is increasingly relied upon in the tropics as a staple for underdeveloped countries.

The potato is a member of the Solanaceae family, which includes several other New World domesticates such as tomatoes, tobacco, and Chile peppers. The genus Solanum is one of many tuber-bearing species found in the Andes. Biologists recognize eight cultivated species within the genus. Like many other cultivated plants, potatoes can be segregated according to the number of chromosomes, and four chromosome groups, diploid to pentaploid, are cultivated in the Andes. Outside of their home, however, only the tetraploids are common. Thousands of distinct types of potatoes are grown in the Andes, distinguished by color, shape, number and depth of "eyes," and other plant characteristics. The International Potato Center in Lima, Peru, has a collection of over 3,600 potato varieties.

EARLY CULTIVATION

The potato was one of several root crops to be domesticated in the Andes, but it is by far the most important. The earliest plant remains of domesticated potatoes occur around 5000 bce. The tubers were modeled in ancient Peruvian ceramics, starting with the Nazca culture after about ce 1 and subsequently throughout the pre-European period. The Incas facilitated empire building by feeding their armies with freeze-dried potatoes. Several South American Indian names exist for potato, but the Quechua term papa was universally adopted in Latin America after its diffusion by the Spaniards in the sixteenth century. There is no evidence of potato cultivation outside of the Andes before 1500.

The Andean tuber first arrived in Europe in Spain (1570) and then England (1588). The actual origin of the European potato is disputed. Genetic evidence suggests that European varieties came from Chile, where the plant was adapted to long days similar to those found in northern Europe. The trip between Chile and Europe in the sixteenth century was long and arduous, and Chilean tubers might not have survived the journey. Moreover, the first potatoes to become established in Europe did better in the shorter days of southern Europe, suggesting that they perhaps came from the central or northern Andes.

The potato was slow to become established in Europe, but once established it played a major role in revolutionizing northern European agriculture. For nearly two centuries following its introduction into Europe, the potato was a curiosity, often regarded with skepticism. In several countries, its cultivation was prohibited because of its resemblance to deadly nightshade and because the plant was believed to cause diseases such as leprosy and tuberculosis. General acceptance of the potato occurred after 1785, following the efforts of the French chemist Parmentier, who suggested that King Louis XVI promote the crop by pretending to guard a mature field with soldiers who were withdrawn at night so the valuable tubers could be stolen.

Potatoes were especially important in increasing the productivity of land in more northerly areas where cereals had been the staple. The tubers produce two or three times as many calories as wheat or rye on the same amount of land, although they require more labor than the cereals. Ireland experienced the first conversion to potatoes as the major staple, and the island's increase in population in the eighteenth century was due to the tuber's productivity. Steadily rising cereal prices in Europe after 1750 led to increased potato cultivation throughout northern Europe.

One of history's worst famines followed the outbreak of a potato fungus disease, late blight (Phytophthora infestans), in Ireland in 1845. More than a million of Ireland's 8 million people died, and more than 1.5 million emigrated. While late blight continues to be a major problem for potato growers everywhere, it is now effectively controlled by varietal resistance and fungicides.

MODERN CULTIVATION

Andean farmers, especially in Peru and Bolivia, continue to grow a vast diversity of potatoes. Part of their crop is bitter potatoes of two Andean species that are frost resistant and can be produced in very high altitudes, up to 13,000 feet above sea level. These bitter tubers are processed by freeze-drying them into chuño. While the tuber remains important to Andean people, per capita consumption is higher in Poland, Germany, and Belgium than in Peru. Argentina, Colombia, and Guatemala are the primary potato exporters in Latin America, and their main markets are in their neighboring countries, rather than overseas.

Potatoes are produced under many different farming conditions and for different uses. Farmers in the Netherlands harvest an average of over 42 metric tons per acre, while in Peru and Bolivia the average yield is less than 10 tons per acre. Russia has more area sown to potatoes than any other country, and it leads the world in per capita consumption of the tubers. Andean farmers cultivate a dozen or more varieties on a small plot of land, while the variety Russet Burbank, first developed in 1874, is grown on tens of thousands of acres in North America. Potatoes are helping to satisfy human hunger in nonindustrial countries where population growth is high. Of the major staples in developing countries, potatoes have shown the greatest increase in production since 1961. Less-developed countries are discovering the same advantage of potatoes that was recognized in Europe 200 years ago. As land resources become increasingly scarce, potatoes deliver higher carbohydrate returns per acre than most other major food crops. Potatoes also contain a good protein-to-calorie ratio and high amounts of vitamins B and C.

The constraints on increased use of potatoes to feed the world include its high water content at harvest (80 percent), difficulty in storing and transporting fresh tubers, and difficulty in multiplying the seed of new varieties. The last problem is being overcome in some areas by the use of true botanical seed rather than tubers as seed.

See alsoAgriculture .

BIBLIOGRAPHY

John S. Niederhauser and William C. Cobb, "The Late Blight of Potatoes," in Scientific American 200 (May 1959): 100-112.

Donovan S. Correll, The Potato and Its Wild Relatives (1962).

Cecil Woodham-Smith, The Great Hunger: Ireland, 1845–1849 (1962).

W. G. Burton, The Potato: A Survey of Its History and Factors Influencing Its Yield, Nutritive Value, Quality, and Storage (1966).

Donald Ugent, "The Potato," in Science 170 (11 December 1970): 1161-1166.

Stephen B. Brush, Heath J. Carney, and Zozimo Huaman, "Dynamics of Andean Potato Agriculture," in Economic Botany 35 (1981): 70-85.

International Potato Center, Potatoes for the Developing World (1984).

E. J. Kahn, "Potatoes: Man Is What He Eats," in The Staffs of Life (1985).

Redcliffe Salaman, The History and Social Influence of the Potato, rev. ed. (1985).

Douglas Horton, Underground Crops: Long-Term Trends in Production of Roots and Tubers (1988).

J. G. Hawkes, The Potato: Evolution, Biodiversity, and Genetic Resources (1990).

Timothy Johns, With Bitter Herbs They Shall Eat It: Chemical Ecology and the Origins of Human Diet and Medicine (1990).

Carlos Ochoa, The Potatoes of South America: Bolivia (1990).

Additional Bibliography

Biarnès, Anne; Jean Philippe Colin; and Ma. de Jesús Santiago Cruz; eds. Agroeconomía de la papa en México. Mexico City: ORSTOM, Colegio de Postgraduados, 1995.

Ochoa, Carlos M., and Franz Frey. Las papas de Sudamérica: Peru. Lima: Centro Internacional de la Papa, 1999.

                                        Stephen B. Brush