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The potato () is a starchy root vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant Solanum tuberosum, a perennial plant in the nightshade family Solanaceae.
Wild potato species can be found from the southern United States to southern Chile. Genetic studies show that the cultivated potato has a single origin, in the area of present-day southern Peru and extreme northwestern Bolivia. Potatoes were domesticated there about 7,000–10,000 years ago from a species in the S. brevicaule complex. Many varieties of the potato are cultivated in the Andes region of South America, where the species is indigenous.
The Spanish introduced potatoes to Europe in the second half of the 16th century from the Americas. They are a staple food in many parts of the world and an integral part of much of the world's food supply. Following millennia of selective breeding, there are now over 5,000 different varieties of potatoes. The potato remains an essential crop in Europe, especially Northern and Eastern Europe, where per capita production is still the highest in the world, while the most rapid expansion in production during the 21st century was in South Asia and eastern Asia, with China and India leading the world production as of 2023.
Like the tomato and the nightshades, the potato is in the genus Solanum; the aerial parts of the potato contain the toxin solanine. Normal potato tubers that have been grown and stored properly produce glycoalkaloids in negligible amounts, but if sprouts and potato skins are exposed to light, tubers can become toxic.
The name "spud" for a potato is from the 15th century spudde, a short and stout knife or dagger, probably related to Danish spyd, "spear". Through semantic change, the general sense of short and thick was transferred to the tuber from around 1840.
At least seven languages: Afrikaans, Dutch, Low Saxon, French, (West) Frisian, Hebrew, Persian and some variants of German, use a term for "potato" that means "earth apple" or "ground apple", from an earlier sense of both pome and apple, referring in general to a ( apple-shaped) fruit or vegetable.
The South Asian word aloo is from Sanskrit आलु (ālu), said to mean the edible root of a variety of Amorphophallus paeoniifolius (elephant foot yam) which potato substituted.
The plant develops to store nutrients. These are not roots but stems that form from thickened rhizomes at the tips of long thin . On the surface of the tubers there are "eyes," which act as sinks to protect the vegetative buds from which the stems originate. The "eyes" are arranged in helical form. In addition, the tubers have small holes that allow breathing, called . The lenticels are circular and their number varies depending on the size of the tuber and environmental conditions. (1992). 9780471573395 ISBN 9780471573395 Tubers form in response to decreasing day length, although this tendency has been minimized in commercial varieties.
After flowering, potato plants produce Potato fruit that resemble green , each containing about 300 very small .R. Plaisted (1982). 9780891180340, American Society of Agronomy, Crop Science Society of America. ISBN 9780891180340
The major species grown worldwide is S. tuberosum (a tetraploid with 48 ), and modern varieties of this species are the most widely cultivated. There are also four diploid species (with 24 chromosomes): S. stenotomum, S. phureja, S. goniocalyx, and S. ajanhuiri. There are two triploid species (with 36 chromosomes): Solanum chaucha and S. juzepczukii. There is one pentaploid cultivated species (with 60 chromosomes): S. curtilobum.
There are two major subspecies of S. tuberosum. The Andean potato, S. tuberosum andigena, is adapted to the short-day conditions prevalent in the mountainous equatorial and tropical regions where it originated. The Chilean potato S. tuberosum tuberosum, native to the Chiloé Archipelago, is in contrast adapted to the long-day conditions prevalent in the higher latitude region of southern Chile.
The earliest archaeologically verified potato tuber remains have been found at the coastal site of Ancon (central Peru), dating to 2500 BC.Martins-Farias 1976; Moseley 1975 The most widely cultivated variety, Solanum tuberosum tuberosum, is indigenous to the Chiloé Archipelago, and has been cultivated by the local indigenous people since before the Spanish conquest.
The International Potato Center, based in Lima, Peru, holds 4,870 types of potato germplasm, most of which are traditional landrace cultivars. In 2009, a draft sequence of the potato genome was made, containing 12 chromosomes and 860 million base pairs, making it a medium-sized plant genome.
It had been thought that most potato derived from a single origin in southern Peru and extreme Northwestern Bolivia, from a species in the S. brevicaule complex. DNA analysis however shows that more than 99% of all current varieties of potatoes are direct descendants of a subspecies that once grew in the of south-central Chile.
Most modern potatoes grown in North America arrived through European settlement and not independently from the South American sources. At least one wild potato species, S. fendleri, occurs in North America; it is used in breeding for resistance to a nematode species that attacks cultivated potatoes. A secondary center of genetic variability of the potato is Mexico, where important wild species that have been used extensively in modern breeding are found, such as the hexaploid S. demissum, used as a source of resistance to the devastating late blight disease ( Phytophthora infestans). Another relative native to this region, Solanum bulbocastanum, has been used to genetically engineer the potato to resist potato blight. Many such wild relatives are useful for breeding resistance to P. infestans.
Little of the diversity found in Solanum ancestral and wild relatives is found outside the original South American range. This makes these South American species highly valuable in breeding. The importance of the potato to humanity is recognised in the United Nations International Day of Potato, to be celebrated on 30 May each year, starting in 2024.
Diploid hybrid potato breeding is a recent area of potato genetics supported by the finding that simultaneous homozygous and fixation of donor alleles is possible. Wild potato species useful for breeding blight resistance include Solanum desmissum and S. stoloniferum, among others.
For culinary purposes, varieties are often differentiated by their waxiness: floury or mealy baking potatoes have more starch (20–22%) than waxy boiling potatoes (16–18%). The distinction may also arise from variation in the comparative ratio of two different potato starch compounds: amylose and amylopectin. Amylose, a long-chain molecule, diffuses from the starch granule when cooked in water, and lends itself to dishes where the potato is mashed. Varieties that contain a slightly higher amylopectin content, which is a highly branched molecule, help the potato retain its shape after being boiled in water. Potatoes that are good for making or potato crisps are sometimes called "chipping potatoes", which means they meet the basic requirements of similar varietal characteristics, being firm, fairly clean, and fairly well-shaped.
Immature potatoes may be sold fresh from the field as "" or "" potatoes and are particularly valued for their taste. They are typically small in size and tender, with a loose skin, and flesh containing a lower level of starch than other potatoes. In the United States they are generally either a Yukon Gold potato or a red potato, called gold creamers or red creamers respectively. In the UK, the Jersey Royal is a famous type of new potato.
Dozens of potato have been plant breeding specifically for their skin or flesh color, including gold, red, and blue varieties. These contain varying amounts of , including carotenoids for gold/yellow or for red or blue cultivars. Carotenoid compounds include provitamin A alpha-carotene and beta-carotene, which are converted to the essential nutrient, vitamin A, during digestion. mainly responsible for red or blue pigmentation in potato cultivars do not have nutritional significance, but are used for visual variety and consumer appeal. In 2010, potatoes were bioengineered specifically for these pigmentation traits. (2025). 9781441973467 ISBN 9781441973467
Potato starch contains two types of glucan, amylose and amylopectin, the latter of which is most industrially useful. Waxy potato varieties produce waxy potato starch, which is almost entirely amylopectin, with little or no amylose. BASF developed the 'Amflora' potato, which was modified to express antisense RNA to inactivate the gene for granule bound starch synthase, an enzyme which catalyzes the formation of amylose. 'Amflora' potatoes therefore produce starch consisting almost entirely of amylopectin, and are thus more useful for the starch industry. In 2010, the European Commission cleared the way for 'Amflora' to be grown in the European Union for industrial purposes only—not for food. Nevertheless, under EU rules, individual countries have the right to decide whether they will allow this potato to be grown on their territory. Commercial planting of 'Amflora' was expected in the Czech Republic and Germany in the spring of 2010, and Sweden and the Netherlands in subsequent years.
The 'Fortuna' GM potato variety developed by BASF was made resistant to late blight by introgression two resistance genes, and , from S. bulbocastanum, a wild potato native to Mexico. is a nucleotide-binding leucine-rich repeat (NB-LRR/NLR), an R-gene-produced immunoreceptor.
In October 2011, BASF requested cultivation and marketing approval as a feed and food from the EFSA. In 2012, GMO development in Europe was stopped by BASF. BASF stops GM crop development in Europe, Deutsche Welle, 17 January 2012 In November 2014, the United States Department of Agriculture (USDA) approved a genetically modified potato developed by Simplot, which contains genetic modifications that prevent bruising and produce less acrylamide when fried than conventional potatoes; the modifications do not cause new proteins to be made, but rather prevent proteins from being made via RNA interference.
Genetically modified varieties have met public resistance in the U.S. and in the European Union.
New tubers may start growing at the surface of the soil. Since exposure to light leads to an undesirable greening of the skins and the development of solanine as a protection from the sun's rays, growers cover surface tubers. Commercial growers cover them by piling additional soil around the base of the plant as it grows (called "hilling" up, or in British English "earthing up"). An alternative method, used by home gardeners and smaller-scale growers, involves covering the growing area with such as straw or plastic sheets.
At farm scale, potatoes require a well-drained neutral or mildly acidic soil (pH 6 or 7) such as a sandy loam. The soil is prepared using deep tillage, for example with a chisel plow or ripper. In areas where irrigation is needed, the field is leveled using a landplane so that water can be supplied evenly. Manure can be added after initial irrigation; the soil is then broken up with a disc harrow. The potatoes are planted using a potato planter machine in rows apart. At garden scale, potatoes are planted in trenches or individual holes some deep in soil, preferably with additional organic matter such as garden compost or manure. Alternatively, they can be planted in containers or bags filled with a free-draining compost. Potatoes are sensitive to heavy , which damage them in the ground or when stored.
Insects that commonly transmit potato diseases or damage the plants include the Colorado potato beetle, the potato tuber moth, the green peach aphid ( Myzus persicae), the potato aphid, Tuta absoluta, , thrips, and . The Colorado potato beetle is considered the most important insect defoliator of potatoes, devastating entire crops. The potato cyst nematode is a microscopic worm that feeds on the roots, thus causing the potato plants to wilt. Since its eggs can survive in the soil for several years, crop rotation is recommended.
Potatoes are usually cured after harvest to improve skin-set. Skin-set is the process by which the skin of the potato becomes resistant to skinning damage. Potato tubers may be susceptible to skinning at harvest and suffer skinning damage during harvest and handling operations. Curing allows the skin to fully set and any wounds to heal. Wound-healing prevents infection and water-loss from the tubers during storage. Curing is normally done at relatively warm temperatures () with high humidity and good gas-exchange if at all possible.
Temperatures below convert the starch in potatoes into sugar, which alters their taste and cooking qualities and leads to higher acrylamide levels in the cooked product, especially in deep-fried dishes. The discovery of acrylamides in starchy foods in 2002 has caused concern, but it is not likely that the acrylamides in food, even if it is somewhat burnt, causes cancer in humans.
Chemicals are used to suppress sprouting of tubers during storage. Chlorpropham is the main chemical used, but it has been banned in the EU over toxicity concerns. Alternatives include ethylene, spearmint and orange oils, and 1,4-dimethylnaphthalene.
Under optimum conditions in commercial warehouses, potatoes can be stored for up to 10–12 months. The commercial storage and retrieval of potatoes involves several phases: first drying surface moisture; wound healing at 85% to 95% relative humidity and temperatures below ; a staged cooling phase; a holding phase; and a reconditioning phase, during which the tubers are slowly warmed. Mechanical ventilation is used at various points during the process to prevent condensation and the accumulation of carbon dioxide.
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The world dedicated to potato cultivation in 2010; the world average yield was . The United States was the most productive country, with a nationwide average yield of .
New Zealand farmers have demonstrated some of the best commercial yields in the world, ranging between 60 and 80 tonnes per hectare, some reporting yields of 88 tonnes of potatoes per hectare.
There is a big gap among various countries between high and low yields, even with the same variety of potato. Average potato yields in developed economies ranges between . China and India accounted for over a third of world's production in 2010, and had yields of respectively. The yield gap between farms in developing economies and developed economies represents an opportunity loss of over of potato, or an amount greater than 2010 world potato production. Potato crop yields are determined by factors such as the crop breed, seed age and quality, crop management practices and the plant environment. Improvements in one or more of these yield determinants, and a closure of the yield gap, could be a major boost to food supply and farmer incomes in the developing world. The food energy yield of potatoes—about —is higher than that of maize (), rice (), wheat (), or ().
Potato plants and crop yields are predicted to benefit from the CO2 fertilization effect, which would increase photosynthesis and therefore growth, reduce water consumption through lower transpiration from stomata and increase starch content in the edible tubers. However, potatoes are more sensitive to soil water deficits than some other staple crops like wheat. In the UK, the amount of arable land suitable for rainfed potato production is predicted to decrease by at least 75%. These changes are likely to lead to increased demand for irrigation water, particularly during the potato growing season.
Potatoes grow best under temperate conditions. Temperatures above have negative effects on potato crops, from physiological damage such as brown spots on tubers, to slower growth, premature sprouting, and lower starch content. These effects reduce crop yield, affecting both the number and the weight of tubers. As a result, areas where current temperatures are near the limits of potatoes' temperature range (e.g. much of sub-Saharan Africa) will likely suffer large reductions in potato crop yields in the future. On the other hand, low temperatures reduce potato growth and present risk of frost damage.
The other approach is through the development of varieties or cultivars which would be more adapted to altered conditions. This can be done through 'traditional' horticulture and genetic modification. These techniques allow for the selection of specific traits as a new cultivar is developed. Certain traits, such as heat stress tolerance, drought tolerance, fast growth/early maturation and disease resistance, may play an important role in creating new cultivars able to maintain yields under stressors induced by climate change.
For instance, developing cultivars with greater heat stress tolerance would be critical for maintaining yields in countries with potato production areas near current cultivars' maximum temperature limits (e.g. Sub-Saharan Africa, India). Superior drought resistance can be achieved through improved water use efficiency (amount of food produced per amount of water used) or the ability to recover from short drought periods and still produce acceptable yields. Further, selecting for deeper root systems may reduce the need for irrigation.
Boiled potatoes are a moderate source (10–19% of the Daily Value, DV) of vitamin C (14% DV) and the B vitamins, vitamin B6 and pantothenic acid (table). Other than a moderate source of potassium (13% DV), boiled potatoes do not supply significant amounts of dietary minerals (table).
The potato is rarely eaten raw because raw potato starch is poorly digested by humans. Depending on the cultivar and preparation method, potatoes can have a high glycemic index (GI) and so are often excluded from the diets of individuals trying to follow a low-GI diet. There is a lack of evidence on the effect of potato consumption on obesity and diabetes.
In the UK, potatoes are not considered by the National Health Service as counting or contributing towards the recommended daily five portions of fruit and vegetables, the 5-A-Day program.
Exposure to light, physical damage, and age increase glycoalkaloid content within the tuber. Different potato varieties contain different levels of glycoalkaloids. The 'Lenape' variety, released in 1967, was withdrawn in 1970 as it contained high levels of glycoalkaloids. Since then, breeders of new varieties test for this, sometimes discarding an otherwise promising cultivar. Breeders try to keep glycoalkaloid levels below . However, when these commercial varieties turn green, their solanine concentrations can go well above this limit, with higher levels in the potato's skin.
Potatoes are used as fodder for livestock. They may be made into silage which can be stored for some months before use.
Potato starch is used in the food industry as a thickener and binder for soups and sauces, in the textile industry as an adhesive, and in the paper industry for the manufacturing of papers and boards.
Potatoes are commonly used in plant research. The consistent parenchyma tissue, the clonal nature of the plant and the low metabolic activity make it an ideal model organism for experiments on wound-response studies and electron transport.
In the 2015 science fiction film The Martian, the protagonist, a stranded astronaut and botanist named Mark Watney, cultivates potatoes on Mars using Martian regolith fertilized with frozen feces.
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