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The potato is a
starch Starch or amylum is a polymeric A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance ...

starch
y
tuber Tubers are enlarged structures used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing season, and ...
of the
plant Plants are predominantly photosynthetic Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respiration, can later be released to fuel ...

plant
''Solanum tuberosum'' and is a
root vegetable Root vegetables are underground plant parts eaten by humans as food Food is any substance consumed to provide Nutrient, nutritional support for an organism. Food is usually of plant, animal or Fungus, fungal origin, and contains essential n ...
native to the
Americas The Americas (also collectively called America) is a landmass comprising the totality of North America, North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with th ...

Americas
. The plant is a
perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and incl ...
in the nightshade family
Solanaceae The Solanaceae , or nightshades, are a family (biology), family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spice ...
. Wild potato
species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individu ...

species
can be found throughout the Americas, from Canada to southern Chile. The potato was originally believed to have been domesticated by
Native Americans Native Americans may refer to: Ethnic groups * Indigenous peoples of the Americas, the pre-Columbian peoples of North and South America and their descendants * Native Americans in the United States * Indigenous peoples in Canada, the indigenous p ...
independently in multiple locations,University of Wisconsin-Madison, ''Finding rewrites the evolutionary history of the origin of potatoes'' (2005

/ref> but later genetic traced a single origin, in the area of present-day southern Peru and extreme northwestern
Bolivia Bolivia ; ay, Wuliwya ; Quechuan languages, Quechua: ''Puliwya'' , officially the Plurinational State of Bolivia, is a landlocked country located in western-central South America. The constitutional capital is Sucre, while the seat of g ...

Bolivia
. Potatoes were
domesticated Domestication is a sustained multi-generational relationship in which one group of organisms assumes a significant degree of influence over the reproduction and care of another group to secure a more predictable supply of resources from that sec ...
there approximately 7,000–10,000 years ago, from a species in the ''
Solanum brevicaule ''Solanum brevicaule'' is a tuberous perennial plant A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shor ...
'' complex. In the
Andes The Andes, Andes Mountains or Andean Mountains ( es, Cordillera de los Andes) are the List of mountain ranges#Mountain ranges by length, longest continental mountain range in the world, forming a continuous highland along the western edge of Sou ...

Andes
region of South America, where the species is
indigenous Indigenous may refer to: *Indigenous peoples Indigenous peoples, also referred to as First people, Aboriginal people, Native people, or autochthonous people, are culturally distinct ethnic groups who are native to a particular place. The term ' ...
, some close relatives of the potato are cultivated. Potatoes were introduced to Europe from the Americas in the second half of the 16th century by the Spanish. Today they are a
staple food A staple food, food staple, or simply a staple, is a food Food is any substance consumed to provide Nutrient, nutritional support for an organism. Food is usually of plant, animal or Fungus, fungal origin, and contains essential nutrients, ...

staple food
in many parts of the world and an integral part of much of the world's
food supply Food security is a measure of the availability of food and individuals' Economic inequality, ability to access it. According the Committee on World Food Security, United Nations’ Committee on World Food Security, food security is defined as the ...
. As of 2014, potatoes were the world's fourth-largest food crop after
maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It can also be ...

maize
(corn),
wheat Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus ''Triticum''; the most widely grown is common wheat Common wheat (''Triticum aestivum'' ...

wheat
, and
rice Rice is the seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was relea ...

rice
. Following millennia of
selective breeding Selective breeding (also called artificial selection) is the process by which humans use animal breeding Animal breeding is a branch of animal science Animal science (also bioscience) is described as "studying the biology Biology i ...
, there are now over 5,000 different types of potatoes. Over 99% of presently cultivated potatoes worldwide descended from varieties that originated in the lowlands of south-central Chile. The importance of the potato as a food source and culinary ingredient varies by region and is still changing. It remains an essential crop in Europe, especially Northern and Eastern Europe, where
per capita ''Per capita'' is a Latin phrase literally meaning "by heads" or "for each head", and idiomatically used to mean "per person". The term is used in a wide variety of social sciences and statistical research contexts, including government statistic ...
production is still the highest in the world, while the most rapid expansion in production over the past few decades has occurred in
southern The name Southern may refer to: * South South is one of the cardinal directions or compass points. South is the opposite of north and is perpendicular to the east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earl ...

southern
and
eastern Asia East Asia is the east East is one of the four cardinal direction The four cardinal directions, or cardinal points, are the directions north North is one of the four compass points or cardinal directions. It is the opposite of south ...
, with China and India leading the world in overall production as of 2018. Like the
tomato The tomato is the edible berry A berry is a small, pulpy, and often edible fruit In botany, a fruit is the seed-bearing structure in flowering plants (also known as angiosperms) formed from the ovary after flowering. Fruits are ...

tomato
, the potato is a nightshade in the genus ''Solanum'', and the vegetative and fruiting parts of the potato contain the toxin
solanine Solanine is a glycoalkaloid poison found in species of the Solanaceae, nightshade family within the genus ''Solanum'', such as the potato (''Solanum tuberosum''), the tomato (''Solanum lycopersicum''), and the eggplant (''Solanum melongena''). I ...

solanine
which is dangerous for human consumption. Normal potato tubers that have been grown and stored properly produce glycoalkaloids in amounts small enough to be negligible to human health, but if green sections of the plant (namely sprouts and skins) are exposed to light, the tuber can accumulate a high enough concentration of glycoalkaloids to affect human health.


Etymology

The English word ''potato'' comes from Spanish (the name used in Spain). The
Royal Spanish Academy The Royal Spanish Academy ( es, Real Academia Española, generally abbreviated as RAE) is Spain's official royal institution with a mission to ensure the stability of the Spanish language Spanish () or Castilian (, ) is a Romance language ...
says the Spanish word is a hybrid of the
Taíno The Taíno were an indigenous people of the Caribbean. At the time of European contact in the late fifteenth century, they were the principal inhabitants of most of Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cub ...
('
sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledon The dicotyledons, also known as dicots (or more rarely dicotyls), are one of the two groups into which all the flowering plant The flowering plants, also known as Angio ...

sweet potato
') and the
Quechua Quechua may refer to: *Quechua people, several indigenous ethnic groups in South America, especially in Peru *Quechuan languages, a Native South American language family spoken primarily in the Andes, derived from a common ancestral language **Sou ...
('potato'). The name originally referred to the
sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledon The dicotyledons, also known as dicots (or more rarely dicotyls), are one of the two groups into which all the flowering plant The flowering plants, also known as Angio ...

sweet potato
although the two plants are not closely related. The 16th-century English herbalist
John Gerard John Gerard (also John Gerarde, c. 1545–1612) was an English botanist with a large herbal garden in London. His 1,484-page illustrated ''Herball, or Generall Historie of Plantes'', first published in 1597, became the most prevalent botany boo ...
referred to sweet potatoes as ''common potatoes'', and used the terms ''bastard potatoes'' and ''Virginia potatoes'' for the species we now call potato. In many of the chronicles detailing agriculture and plants, no distinction is made between the two. Potatoes are occasionally referred to as ''Irish potatoes'' or ''white potatoes'' in the United States, to distinguish them from sweet potatoes. The name ''spud'' for a potato comes from the digging of soil (or a hole) prior to the planting of potatoes. The word has an unknown origin and was originally () used as a term for a short knife or dagger, probably related to the Latin a word root meaning "sword"; compare Spanish , English "spade", and '' spadroon''. It subsequently transferred over to a variety of digging tools. Around 1845, the name transferred to the tuber itself, the first record of this usage being in
New Zealand English New Zealand English (NZE) is the dialect The term dialect (from , , from the word , 'discourse', from , 'through' and , 'I speak') can refer to either of two distinctly different types of phenomena: * One usage refers to a of a ...
. The origin of the word ''spud'' has erroneously been attributed to an 18th-century activist group dedicated to keeping the potato out of Britain, calling itself the Society for the Prevention of Unwholesome Diet. It was Mario Pei's 1949 ''The Story of Language'' that can be blamed for the word's false origin. Pei writes, "the potato, for its part, was in disrepute some centuries ago. Some Englishmen who did not fancy potatoes formed a Society for the Prevention of Unwholesome Diet. The initials of the main words in this title gave rise to spud." Like most other pre-20th century
acronym An acronym is a word In linguistics Linguistics is the scientific study of language A language is a structured system of communication used by humans, including speech (spoken language), gestures (Signed language, sign langu ...
ic origins, this is false, and there is no evidence that a Society for the Prevention of Unwholesome Diet ever existed. At least six languages (Afrikaans, Dutch, French, Hebrew, Persian and some variants of German) are known to use a term for "potato" that translates roughly (or literally) into English as "earth apple" or "ground apple".


Biology

Potato plants are herbaceous
perennial A perennial plant or simply perennial is a plant Plants are predominantly photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and incl ...
s that grow about high, depending on variety, with the leaves dying back after flowering, fruiting and tuber formation. They bear white, pink, red, blue, or purple flowers with yellow
stamen The stamen (plural The plural (sometimes abbreviated An abbreviation (from Latin ''brevis'', meaning ''short'') is a shortened form of a word or phrase, by any method. It may consist of a group of letters, or words taken from the full ve ...
s. Potatoes are mostly by insects such as
bumblebee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only Extant taxon, extant group in the tribe Bombini, though a few extinct ...

bumblebee
s, which carry pollen from other potato plants, though a substantial amount of self-fertilizing occurs as well. Tubers form in response to decreasing day length, although this tendency has been minimized in commercial varieties. After flowering, potato plants produce small green fruits that resemble green es, each containing about 300
seed A seed is an embryonic ''Embryonic'' is the twelfth studio album by experimental rock band the Flaming Lips released on October 13, 2009, on Warner Bros. Records, Warner Bros. The band's first double album, it was released to generally positi ...

seed
s. Like all parts of the plant except the tubers, the fruit contain the toxic
alkaloid Alkaloids are a class of basic BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming language In computer science Computer science deals with the theoretical foundations of ...
solanine Solanine is a glycoalkaloid poison found in species of the Solanaceae, nightshade family within the genus ''Solanum'', such as the potato (''Solanum tuberosum''), the tomato (''Solanum lycopersicum''), and the eggplant (''Solanum melongena''). I ...

solanine
and are therefore unsuitable for consumption. All new potato varieties are grown from seeds, also called "true potato seed", "TPS" or "botanical seed" to distinguish it from seed tubers. New varieties grown from seed can be propagated vegetatively by planting tubers, pieces of tubers cut to include at least one or two eyes, or cuttings, a practice used in greenhouses for the production of healthy seed tubers. Plants propagated from tubers are clones of the parent, whereas those propagated from seed produce a range of different varieties.


Genetics

There are about 5,000 potato varieties worldwide. Three thousand of them are found in the Andes alone, mainly in Peru, Bolivia, Ecuador, Chile, and Colombia. They belong to eight or nine species, depending on the taxonomic school. Apart from the 5,000 cultivated varieties, there are about 200 wild species and subspecies, many of which can be cross-bred with cultivated varieties. Cross-breeding has been done repeatedly to transfer resistances to certain pests and diseases from the gene pool of wild species to the gene pool of cultivated potato species. The major species grown worldwide is ''Solanum tuberosum'' (a
tetraploid Polyploidy is a condition in which the cells of an organism In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecul ...
with 48
chromosome A chromosome is a long DNA molecule with part or all of the genome, genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called histones which, aided by Chaperone (protein), chaperone proteins, bind to and ...

chromosome
s), 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): ''S. chaucha'' and ''S. juzepczukii''. There is one pentaploid cultivated species (with 60 chromosomes): ''S. curtilobum''. There are two major subspecies of ''Solanum tuberosum'': ''andigena'', or Andean; and ''tuberosum'', or Chilean. The Andean potato is adapted to the short-day conditions prevalent in the mountainous equatorial and tropical regions where it originated; the Chilean potato, however, native to the
Chiloé Archipelago The Chiloé Archipelago ( es, Archipiélago de Chiloé, , ) is a group of islands lying off the coast of Chile, in the Los Lagos Region. It is separated from mainland Chile by the Chacao Channel in the north, the Sea of Chiloé in the east and th ...
, is adapted to the long-day conditions prevalent in the higher latitude region of southern Chile. The
International Potato Center The International Potato Center (known as CIP from its Spanish-language name ''Centro Internacional de la Papa)'' is a research facility based in Lima Lima ( ; ) is the capital and the largest city of Peru. It is located in the valleys of t ...
, based in
Lima, Peru Lima ( ; ) is the capital and the largest city of Peru , , image_flag = Flag_of_Peru.svg , image_coat = Escudo_nacional_del_Perú.svg , other_symbol = Great Seal of the State , other_symbol ...
, holds 4,870 types of potato
germplasm Germplasm are living genetic resources such as seeds or tissues that are maintained for the purpose of animal Animals (also called Metazoa) are organisms that form the Animalia. With few exceptions, animals , , are , can , and grow fr ...
, most of which are traditional
landrace A landrace is a domesticated Domestication is a sustained multi-generational relationship in which one group of organisms assumes a significant degree of influence over the reproduction and care of another group to secure a more predictable s ...
cultivars. The international Potato Genome Sequencing Consortium announced in 2009 that they had achieved a draft sequence of the potato genome, containing 12 chromosomes and 860 million base pairs, making it a medium-sized plant genome. More than 99 percent of all current
varieties Variety may refer to: Science and technology Mathematics * Algebraic variety, the set of solutions of a system of polynomial equations * Variety (universal algebra), classes of algebraic structures defined by equations in universal algebra Hort ...
of potatoes currently grown are direct descendants of a subspecies that once grew in the
lowland Upland and lowland are conditional descriptions of a plain In geography Geography (from Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Re ...
s of south-central
Chile Chile, officially the Republic of Chile, is a country in the western part of South America South America is a entirely in the and mostly in the , with a relatively small portion in the . It can also be described as the southern ...

Chile
. Nonetheless, genetic testing of the wide variety of
cultivar A cultivar is a type of plant that people have bred for desired traits, which are reproduced in each new generation by a method such as grafting, tissue culture or carefully controlled seed production. Most cultivars arise from purposeful human ...
s and wild species affirms that all potato subspecies derive from a single
origin Origin(s) or The Origin may refer to: Arts, entertainment, and media Comics and manga * Origin (comics), ''Origin'' (comics), a Wolverine comic book mini-series published by Marvel Comics in 2002 * The Origin (Buffy comic), ''The Origin'' (Bu ...
in the area of present-day southern
Peru , , image_flag = Flag_of_Peru.svg , image_coat = Escudo_nacional_del_Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (device), National seal , national_mott ...

Peru
and extreme Northwestern
Bolivia Bolivia ; ay, Wuliwya ; Quechuan languages, Quechua: ''Puliwya'' , officially the Plurinational State of Bolivia, is a landlocked country located in western-central South America. The constitutional capital is Sucre, while the seat of g ...

Bolivia
(from a species in the ''Solanum brevicaule'' complex). Most modern potatoes grown in North America arrived through European settlement and not independently from the South American sources, although at least one wild potato species, '' Solanum fendleri'', naturally ranges from Peru into Texas, where it is used in breeding for resistance to a
nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...

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 '' Solanum demissum'', as a source of resistance to the devastating late blight disease. Another relative native to this region, '' Solanum bulbocastanum'', has been used to genetically engineer the potato to resist potato blight.


Varieties

There are close to 4,000 varieties of potato each of which has specific agricultural or culinary attributes. Around 80 varieties are commercially available in the UK. In general, varieties are categorized into a few main groups based on common characteristics, such as russet potatoes (rough brown skin), red potatoes, white potatoes, yellow potatoes (also called Yukon potatoes) and purple potatoes. For culinary purposes, varieties are often differentiated by their waxiness: floury or mealy ''baking'' potatoes have more
starch Starch or amylum is a polymeric A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance ...
(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 Amylose is a polysaccharide , a beta-glucan polysaccharide Image:amylose 3Dprojection.svg">350px, Amylose is a linear polymer of glucose mainly linked with α(1→4) bonds. It can be made of several thousands of glucose units. It is one of the two ...

amylose
and
amylopectin Amylopectin is a water-soluble Subscription required for online access. polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose. Glucose units are linke ...
. 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
potato chip A potato chip (often just chip, or crisp in British and Irish English) is a thin slice of potato The potato is a starch Starch or amylum is a polymeric A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance Sub ...

potato chip
s 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 "creamer" or "new" 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 Starch or amylum is a polymeric A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance ...
than other potatoes. In the USA 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. They are distinct from "baby", "salad" or " fingerling" potatoes, which are small and tend to have waxy flesh, but are grown to maturity and can be stored for months before being sold. The European Cultivated Potato Database (ECPD) is an online collaborative database of potato variety descriptions that is updated and maintained by the
Scottish Agricultural Science Agency SASA (formerly the Scottish Agricultural Science Agency) is a division of the Scottish Government Agriculture and Rural Delivery Directorate. It provides scientific advice and support on a range of agricultural and environmental topics to the Scott ...
within the framework of the European Cooperative Programme for Crop Genetic Resources Networks (ECP/GR)—which is run by the International Plant Genetic Resources Institute (IPGRI).


Pigmentation

Dozens of potato
cultivar A cultivar is a type of plant that people have bred for desired traits, which are reproduced in each new generation by a method such as grafting, tissue culture or carefully controlled seed production. Most cultivars arise from purposeful human ...
s have been selectively bred specifically for their skin or, more commonly, flesh
color Color (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. Currently, American Engli ...
, including gold, red, and blue varieties that contain varying amounts of
phytochemical Phytochemicals are chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entity, molecular entities) composed of atoms from more than one chemical element, element held together by che ...
s, including
carotenoids Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and fungi. Carotenoids give the characteristic color to pumpkins, carro ...
for gold/yellow or
polyphenol Polyphenols () are a large family of naturally occurring s characterized by multiples of units. They are abundant in plants and structurally diverse. Polyphenols include s, , and , some of which have been used historically as s and for . Et ...

polyphenol
s for red or blue cultivars. Carotenoid compounds include provitamin A
alpha-carotene α-Carotene is a form of carotene The term carotene (also carotin, from the Latin ''carota'', "carrot") is used for many related unsaturated hydrocarbon 300px, Structure of an ethene molecule, the simplest unsaturated hydrocarbon Unsaturate ...

alpha-carotene
and , which are converted to the
essential nutrient A nutrient is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance, a material with a definite chemical composition * Matter, anything that has mass and ta ...
,
vitamin A Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, (also known as retinaldehyde), retinoic acid and several provitamin A carotenoids (most notably Beta-Carotene, beta-carotene). Vitamin A has mul ...

vitamin A
, during digestion.
Anthocyanin Anthocyanins (also anthocyans; from Ancient Greek, Greek: (''anthos'') "flower" and / ''kyaneos/kyanous'' "dark blue") are solubility, water-soluble vacuole, vacuolar pigments that, depending on their pH, may appear red, purple, blue or black. F ...

Anthocyanin
s 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.


Genetically engineered potatoes

Genetic research has produced several
genetically modified Genetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism's gene In biology, a gene (from ''genos'' "...Wilhelm Johannsen coined the word gene to describe the Mendelian_in ...
varieties. 'New Leaf', owned by
Monsanto Company The Monsanto Company () was an American agrochemical and agricultural biotechnology corporation founded in 1901. In 2018, it was acquired by Bayer as part of its crop science division. It was headquartered in Creve Coeur, Missouri. Monsanto ...
, incorporates genes from ''
Bacillus thuringiensis ''Bacillus thuringiensis'' (or Bt) is a Gram-positive 300px, Violet-stained gram-positive cocci and pink-stained gram-negative bacillus (shape), bacilli In bacteriology, gram-positive bacteria are bacteria that give a positive result in the G ...

Bacillus thuringiensis
'', which confers resistance to the
Colorado potato beetle The Colorado potato beetle (''Leptinotarsa decemlineata''), also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle, or the potato bug, is a major Pest (organism), pest of potato crops. It is about long, with a ...

Colorado potato beetle
; 'New Leaf Plus' and 'New Leaf Y', approved by US regulatory agencies during the 1990s, also include resistance to viruses.
McDonald's McDonald's is an American fast food Fast food is a type of Mass production, mass-produced food designed for commercial resale and with a strong priority placed on "speed of service" versus other relevant factors involved in food scie ...

McDonald's
,
Burger King Burger King (BK) is an American multinational chain Image:Kettenvergleich.jpg, Roller chains A chain is a wikt:series#Noun, serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to t ...

Burger King
,
Frito-Lay Frito-Lay is an American subsidiary of PepsiCo that manufactures, markets, and sells corn chips, potato chips, and other snack foods. The primary snack food brands produced under the Frito-Lay name include Fritos corn chips, Cheetos cheese-flavore ...
, and
Procter & Gamble The Procter & Gamble Company (P&G) is an American multinational consumer goods A final good or consumer good is a final product In Production (economics), production, a final product, or finished product is a product (business), product th ...
announced they would not use genetically modified potatoes, and Monsanto published its intent to discontinue the line in March 2001. Waxy potato varieties produce two main kinds of potato starch,
amylose Amylose is a polysaccharide , a beta-glucan polysaccharide Image:amylose 3Dprojection.svg">350px, Amylose is a linear polymer of glucose mainly linked with α(1→4) bonds. It can be made of several thousands of glucose units. It is one of the two ...

amylose
and
amylopectin Amylopectin is a water-soluble Subscription required for online access. polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose. Glucose units are linke ...
, the latter of which is most industrially useful.
BASF BASF SE is a German multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * Multinational state, a sovere ...

BASF
developed the
Amflora Amflora (also known as EH92-527-1) is a genetically modified potato cultivar developed by BASF Plant Science. "Amflora" potato plants produce pure amylopectin starch that is processed to waxy potato starch. It was approved for industrial application ...
potato, which was modified to express
antisense RNA Antisense RNA (asRNA), also referred to as antisense transcript, natural antisense transcriptNatural antisense transcripts (NATs) are a group of RNAs encoded within a cell that have transcript complementarity to other RNA transcripts. They have be ...
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 Amylopectin is a water-soluble Subscription required for online access. polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose. Glucose units are linke ...
, 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 Sweden ( sv, Sverige ), officially the Kingdom of Sweden ( sv, links=no, Konungariket Sverige ), is a Nordic country The Nordic countries, or the Nordics, are a geographical and cultural region In geography, regions are areas that ...

Sweden
and the Netherlands in subsequent years. Another GM potato variety developed by BASF is 'Fortuna' which was made resistant to
late blight ''Phytophthora infestans'' is an oomycete or water mold, a microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is ...
by adding two resistance genes, blb1 and blb2, which originate from the Mexican wild potato Solanum bulbocastanum. 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. In November 2014, the USDA approved a genetically modified potato developed by J.R. Simplot Company, which contains genetic modifications that prevent bruising and produce less
acrylamide Acrylamide (or acrylic amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a chemical compound, compound with the general formula RC(=O)NR′R″, where R, R', and R″ represent organic compound, orga ...
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 RNA interference (RNAi) is a biological process in which RNA Ribonucleic acid (RNA) is a polymer A polymer (; Greek ''wikt:poly-, poly-'', "many" + ''wikt:-mer, -mer'', "part") is a Chemical substance, substance or material consisting o ...
. Genetically modified varieties have met public resistance in the United States and in the European Union.


Biosynthesis

Sucrose is a product of photosynthesis as it is in many photosynthetic organisms. As sucrose synthase activity begins, Ferreira et al 2010 finds starch
biosynthesis Biosynthesis is a multi-step, enzyme Enzymes () are proteins that act as biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and ...

biosynthesis
genes to begin transcription at the same time. This transcription - including starch synthase - also shows a
diurnal Diurnal ("daily Daily or The Daily may refer to: Journalism * Daily newspaper A newspaper is a Periodical literature, periodical publication containing written News, information about current events and is often typed in black ink with a ...
rhythm, correlating with the sucrose supply arriving from the leaves.


History

The potato was first domesticated in the region of modern-day southern
Peru , , image_flag = Flag_of_Peru.svg , image_coat = Escudo_nacional_del_Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (device), National seal , national_mott ...

Peru
and northwestern
Bolivia Bolivia ; ay, Wuliwya ; Quechuan languages, Quechua: ''Puliwya'' , officially the Plurinational State of Bolivia, is a landlocked country located in western-central South America. The constitutional capital is Sucre, while the seat of g ...

Bolivia
by pre-Columbian farmers, around Lake Titicaca. It has since spread around the world and become a
staple crop File:Speltkorrels.jpg, 215px, Unprocessed seeds of spelt, a historically important staple food A staple food, food staple, or simply a staple, is a food that is eaten routinely and in such quantities that it constitutes a dominant portion of a stan ...

staple crop
in many countries. The earliest archaeologically verified potato tuber remains have been found at the coastal site of
Ancon Ancon Ltd is a company that designs and manufactures stainless steel products for the construction industry founded and still based in Sheffield, United Kingdom. The main products being "Wall Tie", and brickwork support systems. Ancon is part of ...
(central
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Peru
), dating to 2500 BC. The most widely cultivated variety, '' Solanum tuberosum tuberosum'', is indigenous to the
Chiloé Archipelago The Chiloé Archipelago ( es, Archipiélago de Chiloé, , ) is a group of islands lying off the coast of Chile, in the Los Lagos Region. It is separated from mainland Chile by the Chacao Channel in the north, the Sea of Chiloé in the east and th ...
, and has been cultivated by the local
indigenous people Indigenous peoples, also referred to as first peoples, first nations, aboriginal peoples, native peoples (with these terms often capitalized when referred to relating to specific countries), or autochthonous peoples, are culturally distinct e ...
since before the
Spanish conquest The Spanish Empire ( es, Imperio Español; la, Imperium Hispanicum), historically known as the Hispanic Monarchy ( es, Monarquía Hispánica) and as the Catholic Monarchy ( es, Monarquía Católica), was a colonial empire A colonial empire is a ...
. According to conservative estimates, the introduction of the potato was responsible for a quarter of the growth in
Old World The Old World consists of Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% o ...
population and urbanization between 1700 and 1900. In the Altiplano, potatoes provided the principal energy source for the
Inca civilization The Incas were most notable for establishing the Inca Empire The Inca Empire ( qu, Tawantinsuyu,  "four parts together"), Quechuan and Aymaran spelling shift, also known as the Incan Empire and the Inka Empire, was the largest empire in ...
, its predecessors, and its Spanish successor. Following the
Spanish conquest of the Inca Empire The Spanish conquest of the Inca Empire, also known as the Conquest of Peru, was one of the most important campaigns in the Spanish colonization of the Americas The Spanish colonization of the Americas began under the Crown of Castile ...
, the Spanish introduced the potato to Europe in the second half of the 16th century, part of the
Columbian exchange #REDIRECT Columbian exchange#REDIRECT Columbian exchange native plants. Clockwise, from top left: 1. Citrus (Rutaceae); 2. Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agr ...
. The staple was subsequently conveyed by European (possibly including
Russian Russian refers to anything related to Russia, including: *Russians (русские, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *Rossiyane (россияне), Russian language term ...
) mariners to territories and ports throughout the world, especially their colonies. The potato was slow to be adopted by European and colonial farmers, but after 1750 it became an important food staple and field crop and played a major role in the European 19th century population boom. However, lack of genetic diversity, due to the very limited number of varieties initially introduced, left the crop vulnerable to disease. In 1845, a plant disease known as late blight, caused by the fungus-like
oomycete Oomycota or oomycetes () form a distinct phylogenetic In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, mole ...
''
Phytophthora infestans ''Phytophthora infestans'' is an oomycete Oomycota or oomycetes () form a distinct phylogenetic In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry ...
'', spread rapidly through the poorer communities of western
Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic. It is separated from Great Britain to its east by the North Channel (Great Britain and Ireland), North Channel, the Irish Sea ...

Ireland
as well as parts of the
Scottish Highlands The Highlands ( sco, the Hielands; gd, a’ Ghàidhealtachd , 'the place of the Gaels The Gaels ( ; ga, Na Gaeil ; gd, Na Gàidheil ; gv, Ny Gaeil ) are an ethnolinguistic group An ethnolinguistic group (or ethno-linguistic group) ...

Scottish Highlands
, resulting in the crop failures that led to the
Great Irish Famine The Great Famine ( ga, an Gorta Mór ), also known as the Great Hunger, the Famine (mostly within Ireland) or the Irish Potato Famine (mostly outside Ireland), was a period of mass starvation and disease A disease is a particular abn ...
. Thousands of varieties still persist in the Andes however, where over 100 cultivars might be found in a single valley, and a dozen or more might be maintained by a single agricultural household.


Production

In 2018, world production of potatoes was 368 million
tonne The tonne ( or ; symbol: t) is a metric unit of mass equal to 1,000 kilogram The kilogram (also kilogramme) is the base unit of mass Mass is the physical quantity, quantity of ''matter'' in a physical body. It is also a meas ...
s, led by China with 27% of the total (table). Other major producers were India, Russia, Ukraine and the United States. It remains an essential crop in Europe (especially northern and eastern Europe), where per capita production is still the highest in the world, but the most rapid expansion over the past few decades has occurred in southern and eastern Asia.


Nutrition

According to the United States Department of Agriculture, a typical raw potato is 79% water, 17%
carbohydrates is a disaccharide A disaccharide (also called a double sugar or ''biose'') is the sugar Sugar is the generic name for sweet-tasting, soluble carbohydrate is a disaccharide found in animal milk. It consists of a molecule of D-galacto ...
(88% is
starch Starch or amylum is a polymeric A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance Substance may refer to: * Substance (Jainism), a term in Jain ontology to denote the base or owner of attributes * Chemical substance ...
), 2%
protein Proteins are large biomolecule , showing alpha helices, represented by ribbons. This poten was the first to have its suckture solved by X-ray crystallography by Max Perutz and Sir John Cowdery Kendrew in 1958, for which they received a No ...

protein
, and contains negligible
fat In nutrition Nutrition is the biochemical Biochemistry or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided ...

fat
(see table). In a portion, raw potato provides of food energy and is a rich source of
vitamin B6 Vitamin B6 is one of the , and thus an . The term refers to a group of six chemically similar compounds, i.e., "s", which can be interconverted in biological systems. Its active form, , serves as a in more than 140 reactions in , , and meta ...
and
vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a vitamin found in various foods and sold as a dietary supplement. It is used to prevent and treat scurvy. Vitamin C is an Nutrient#Essential nutrients, essential nutrient involved in t ...

vitamin C
(23% and 24% of the
Daily Value The Reference Daily Intake (RDI) used in nutrition labeling on food and dietary supplement products in the U.S. and Canada is the daily intake level of a nutrient A nutrient is a substance used by an organism to survive, grow, and reproduce. The ...
, respectively), with no other vitamins or minerals in significant amount (see table). The potato is rarely eaten raw because raw potato starch is poorly digested by humans. When a potato is baked, its contents of vitamin B6 and vitamin C decline notably, while there is little significant change in the amount of other nutrients. Potatoes are often broadly classified as having a high
glycemic index The glycemic index (GI; ) is a number from 0 to 100 assigned to a food, with pure glucose arbitrarily given the value of 100, which represents the relative rise in the blood glucose level two hours after consuming that food. The GI of a specific fo ...
(GI) and so are often excluded from the diets of individuals trying to follow a low-GI diet. The GI of potatoes can vary considerably depending on the cultivar, growing conditions and storage, preparation methods (by cooking method, whether it is eaten hot or cold, whether it is mashed or cubed or consumed whole), and accompanying foods consumed (especially the addition of various high-fat or high-protein toppings). Consuming reheated or pre-cooked and cooled potatoes may yield a lower GI effect due to the formation of resistant starch. In the UK, potatoes are not considered by the National Health Service (NHS) as counting or contributing towards the recommended daily 5 A Day, five portions of fruit and vegetables, the 5-A-Day program.


Comparison to other staple foods

This table shows the nutrient content of potatoes next to other major staple foods, each one measured in its respective raw state on a Dry matter#Dry matter basis, dry weight basis to account for their different water contents, even though staple foods are not commonly eaten raw and are usually sprouted or cooked before eating. In sprouted and cooked form, the relative nutritional and anti-nutritional contents of each of these grains (or other foods) may be different from the values in this table. Each nutrient (every row) has the highest number highlighted to show the staple food with the greatest amount in a dry 100 gram portion.


Toxicity

Potatoes contain Toxicity, toxic compounds known as glycoalkaloids, of which the most prevalent are
solanine Solanine is a glycoalkaloid poison found in species of the Solanaceae, nightshade family within the genus ''Solanum'', such as the potato (''Solanum tuberosum''), the tomato (''Solanum lycopersicum''), and the eggplant (''Solanum melongena''). I ...

solanine
and chaconine. Solanine is found in other plants in the same family,
Solanaceae The Solanaceae , or nightshades, are a family (biology), family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spice ...
, which includes such plants as deadly nightshade (''Atropa belladonna''), henbane (''Hyoscyamus niger'') and tobacco (''Nicotiana, Nicotiana spp.''), as well as the food plants eggplant and
tomato The tomato is the edible berry A berry is a small, pulpy, and often edible fruit In botany, a fruit is the seed-bearing structure in flowering plants (also known as angiosperms) formed from the ovary after flowering. Fruits are ...

tomato
. These compounds, which protect the potato plant from its predators, are generally concentrated in its leaves, flowers, sprouts, and fruits (in contrast to the tubers). In a summary of several studies, the glycoalkaloid content was highest in the flowers and sprouts and lowest in the tuber flesh. (The glycoalkaloid content was, in order from highest to lowest: flowers, sprouts, leaves, tuber skin, roots, berries, peel [skin plus outer cortex of tuber flesh], stems, and tuber flesh). Exposure to light, physical damage, and age increase glycoalkaloid content within the tuber. Cooking at high temperatures—over —partly destroys these compounds. The concentration of glycoalkaloids in Solanum jamesii, wild potatoes is sufficient to produce toxic effects in humans. Glycoalkaloid poisoning may cause headaches, diarrhea, cramps, and, in severe cases, coma and death. However, poisoning from cultivated potato varieties is very rare. Light exposure causes greening from chlorophyll synthesis, giving a visual clue as to which areas of the tuber may have become more toxic. However, this does not provide a definitive guide, as greening and glycoalkaloid accumulation can occur independently of each other. Different potato varieties contain different levels of glycoalkaloids. The Lenape (potato), Lenape variety was released in 1967 but was withdrawn in 1970 as it contained high levels of glycoalkaloids. Since then, breeders developing new varieties test for this, and sometimes have to discard an otherwise promising
cultivar A cultivar is a type of plant that people have bred for desired traits, which are reproduced in each new generation by a method such as grafting, tissue culture or carefully controlled seed production. Most cultivars arise from purposeful human ...
. Breeders try to keep glycoalkaloid levels below 200 mg/kg (200 Parts-per notation, ppmw). However, when these commercial varieties turn green, they can still approach
solanine Solanine is a glycoalkaloid poison found in species of the Solanaceae, nightshade family within the genus ''Solanum'', such as the potato (''Solanum tuberosum''), the tomato (''Solanum lycopersicum''), and the eggplant (''Solanum melongena''). I ...

solanine
concentrations of 1000 mg/kg (1000 ppmw). In normal potatoes, analysis has shown solanine levels may be as little as 3.5% of the breeders' maximum, with 7–187 mg/kg being found. While a normal potato tuber has 12–20 mg/kg of glycoalkaloid content, a green potato tuber contains 250–280 mg/kg and its skin has 1500–2200 mg/kg.


Growth and cultivation


Seed potatoes

Potatoes are generally grown from ''seed potatoes'', tubers specifically grown to be free from disease and to provide consistent and healthy plants. To be disease free, the areas where seed potatoes are grown are selected with care. In the US, this restricts production of seed potatoes to only 15 states out of all 50 states where potatoes are grown. These locations are selected for their cold, hard winters that kill pests and summers with long sunshine hours for optimum growth. In the UK, most seed potatoes originate in Scotland, in areas where westerly winds reduce aphid attack and the spread of Potato virus Y, potato virus pathogens.


Phases of growth

Potato growth can be divided into five phases. During the first phase, sprouts emerge from the seed potatoes and root growth begins. During the second, photosynthesis begins as the plant develops leaves and branches above-ground and stolons develop from lower leaf axils on the below-ground stem. In the third phase the tips of the stolons swell forming new tubers and the shoots continue to grow and flowers typically develop soon after. Tuber bulking occurs during the fourth phase, when the plant begins investing the majority of its resources in its newly formed tubers. At this phase, several factors are critical to a good yield: optimal soil moisture and temperature, soil nutrient availability and balance, and resistance to Pest (organism), pest attacks. The fifth phase is the maturation of the tubers: the leaves and stems senesce and the tuber skins harden.


Challenges

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 Solanine is a glycoalkaloid poison found in species of the Solanaceae, nightshade family within the genus ''Solanum'', such as the potato (''Solanum tuberosum''), the tomato (''Solanum lycopersicum''), and the eggplant (''Solanum melongena''). I ...

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 organic mulches such as straw or plastic sheets. Correct potato husbandry can be an arduous task in some circumstances. Good ground preparation, harrowing, plough, plowing, and rolling are always needed, along with a little grace from the weather and a good source of water. Three successive plowings, with associated harrowing and rolling, are desirable before planting. Eliminating all root-weeds is desirable in potato cultivation. In general, the potatoes themselves are grown from the eyes of another potato and not from seed. Home gardeners often plant a piece of potato with two or three eyes in a hill of mounded soil. Commercial growers plant potatoes as a row crop using seed tubers, young plants or microtubers and may mound the entire row. Seed potato crops are roguing, rogued in some countries to eliminate diseased plants or those of a different variety from the seed crop. Potatoes are sensitive to heavy frosts, which damage them in the ground. Even cold weather makes potatoes more susceptible to bruising and possibly later rotting, which can quickly ruin a large stored crop.


Pests and disease

The historically significant ''
Phytophthora infestans ''Phytophthora infestans'' is an oomycete Oomycota or oomycetes () form a distinct phylogenetic In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry ...
'' (late blight) remains an ongoing problem in Europe and the United States. Other potato diseases include ''Rhizoctonia'', ''Sclerotinia'', Pectobacterium carotovorum, black leg, powdery mildew, powdery scab and Potato leafroll virus, leafroll virus. Insects that commonly transmit potato diseases or damage the plants include the
Colorado potato beetle The Colorado potato beetle (''Leptinotarsa decemlineata''), also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle, or the potato bug, is a major Pest (organism), pest of potato crops. It is about long, with a ...

Colorado potato beetle
, the potato tuber moth, the green peach aphid (''Myzus persicae''), the potato aphid, ''Tuta absoluta'', beet leafhoppers, thrips, and mites. 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. According to an Environmental Working Group analysis of USDA and FDA pesticide residue tests performed from 2000 through 2008, 84% of the 2,216 tested potato samples contained detectable traces of at least one pesticide. A total of 36 unique pesticides were detected on potatoes over the 2,216 samples, though no individual sample contained more than 6 unique pesticide traces, and the average was 1.29 detectable unique pesticide traces per sample. The average quantity of all pesticide traces found in the 2,216 samples was 1.602 Parts per million, ppm. While this was a very low value of pesticide residue, it was the highest amongst the 50 vegetables analyzed.


Harvest

At harvest time, gardeners usually dig up potatoes with a long-handled, three-prong "grape" (or graip), i.e., a Garden fork, spading fork, or a potato hook, which is similar to the graip but with tines at a 90Degree (angle), ° angle to the handle. In larger plots, the plow is the fastest implement for unearthing potatoes. Commercial harvesting is typically done with large potato harvesters, which scoop up the plant and surrounding earth. This is transported up an apron chain consisting of steel links several feet wide, which separates some of the dirt. The chain deposits into an area where further separation occurs. Different designs use different systems at this point. The most complex designs use vine choppers and shakers, along with a blower system to separate the potatoes from the plant. The result is then usually run past workers who continue to sort out plant material, stones, and rotten potatoes before the potatoes are continuously delivered to a wagon or truck. Further inspection and separation occurs when the potatoes are unloaded from the field vehicles and put into storage. 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.


Storage

Storage facilities need to be carefully designed to keep the potatoes alive and slow the natural process of sprouting which involves the breakdown of starch. It is crucial that the storage area be dark, ventilated well, and, for long-term storage, maintained at temperatures near . For short-term storage, temperatures of about are preferred.Potato storage, value Preservation: Temperatures below convert the starch in potatoes into sugar, which alters their taste and cooking qualities and leads to higher
acrylamide Acrylamide (or acrylic amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a chemical compound, compound with the general formula RC(=O)NR′R″, where R, R', and R″ represent organic compound, orga ...
levels in the cooked product, especially in deep-fried dishes. The discovery of acrylamides in starchy foods in 2002 has led to international health concerns. They are believed to be probable carcinogens and their occurrence in cooked foods is being studied for potentially influencing health problems. Chemicals are used to suppress sprouting of tubers during storage. Chlorpropham (CIPC) is the main chemical used, but toxicity concerns have led to it being banned in the EU. Alternatives are applying maleic hydrazide to the crop whilst it is still growing or the use of 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. Ventilation (architecture), Mechanical ventilation is used at various points during the process to prevent condensation and the accumulation of carbon dioxide.


Yield

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 . United Kingdom was a close second. 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 38 and 44 tonnes per hectare. China and India accounted for over a third of world's production in 2010, and had yields of 14.7 and 19.9 tonnes per hectare respectively. The yield gap between farms in developing economies and developed economies represents an opportunity loss of over 400 million tonnes 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, can 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 soybeans ().


Climate change

Climate change is predicted to have significant effects on global potato production. Like many crops, potatoes are likely to be affected by changes in atmospheric carbon dioxide, temperature and precipitation, as well as interactions between these factors. As well as affecting potatoes directly, climate change will also affect the distributions and populations of many potato diseases and pests.


Uses

Potatoes are prepared in many ways: skin-on or peeled, whole or cut up, with seasonings or without. The only requirement involves cooking to swell the starch granules. Most potato dishes are served hot but some are first cooked, then served cold, notably potato salad and potato chip, potato chips (crisps). Common dishes are: mashed potatoes, which are first boiled (usually peeled), and then mashed with milk or yogurt and butter; whole baked potatoes; boiling, boiled or steaming, steamed potatoes; French fries, French-fried potatoes or chips; cut into cubes and roasting, roasted; scalloped potatoes, scalloped, diced, or sliced and fried (home fries); grated into small thin strips and fried (hash browns); grated and formed into dumplings, Rösti or potato pancakes. Unlike many foods, potatoes can also be easily cooked in a microwave oven and still retain nearly all of their nutritional value, provided they are covered in ventilated plastic wrap to prevent moisture from escaping; this method produces a meal very similar to a steamed potato, while retaining the appearance of a conventionally baked potato. Potato chunks also commonly appear as a stew ingredient. Potatoes are boiled between 10 and 25 minutes, depending on size and type, to become soft.


Other than for eating

Potatoes are also used for purposes other than eating by humans, for example: * Potatoes are used to brew alcoholic beverages such as vodka, poitín, or akvavit. * They are also used as fodder for livestock. Livestock-grade potatoes, considered too small and/or blemished to sell or market for human use but suitable for fodder use, have been called ''chats'' in some dialects. They may be stored in bins until use; they are sometimes silage, ensiled. Some farmers prefer to steam them rather than feed them raw and are equipped to do so efficiently. * 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 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, model tissue for experiments on wound-response studies and electron transport. * Potatoes have been delivered with personalized messages as a novelty. Potato delivery services include Potato Parcel and Mail A Spud.


Latin America

Peruvian cuisine naturally contains the potato as a primary ingredient in many dishes, as around 3,000 varieties of this tuber are grown there. Some of the more notable dishes include boiled potato as a base for several dishes or with ají (sauce), ají-based sauces like in Papa a la Huancaína or ocopa, diced potato for its use in soups like in cau cau, or in Carapulca with dried potato (papa seca). Smashed condimented potato is used in causa Limeña and papa rellena. French-fried potatoes are a typical ingredient in Peruvian stir-fries, including the classic dish lomo saltado. Chuño is a freeze-drying, freeze-dried potato product traditionally made by Quechuas, Quechua and Aymara people, Aymara communities of
Peru , , image_flag = Flag_of_Peru.svg , image_coat = Escudo_nacional_del_Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (device), National seal , national_mott ...

Peru
and
Bolivia Bolivia ; ay, Wuliwya ; Quechuan languages, Quechua: ''Puliwya'' , officially the Plurinational State of Bolivia, is a landlocked country located in western-central South America. The constitutional capital is Sucre, while the seat of g ...

Bolivia
, and is known in various countries of South America, including
Peru , , image_flag = Flag_of_Peru.svg , image_coat = Escudo_nacional_del_Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (device), National seal , national_mott ...

Peru
, Bolivia, Argentina, and
Chile Chile, officially the Republic of Chile, is a country in the western part of South America South America is a entirely in the and mostly in the , with a relatively small portion in the . It can also be described as the southern ...

Chile
. In Chile's
Chiloé Archipelago The Chiloé Archipelago ( es, Archipiélago de Chiloé, , ) is a group of islands lying off the coast of Chile, in the Los Lagos Region. It is separated from mainland Chile by the Chacao Channel in the north, the Sea of Chiloé in the east and th ...
, potatoes are the main ingredient of many dishes, including milcaos, chapaleles, curanto and chochoca. In Ecuador, the potato, as well as being a staple with most dishes, is featured in the hearty ''locro de papas'', a thick soup of potato, squash, and cheese.


Europe

In the UK, potatoes form part of the traditional staple, fish and chips. Roast potatoes are commonly served as part of a Sunday roast, Sunday roast dinner and mashed potatoes form a major component of several other traditional dishes, such as shepherd's pie, bubble and squeak, and bangers and mash. New potatoes may be cooked with mentha, mint and are often served with butter. The Tattie scone is a popular Scottish dish containing potatoes. Colcannon is a traditional Irish food made with mashed potato, shredded kale or cabbage, and onion; champ (food), champ is a similar dish. Boxty pancakes are eaten throughout Ireland, although associated especially with the North, and in Irish diaspora communities; they are traditionally made with grated potatoes, soaked to loosen the starch and mixed with flour, buttermilk and baking powder. A variant eaten and sold in Lancashire, especially Liverpool, is made with cooked and mashed potatoes. In the UK, game chips are a traditional accompaniment to roast gamebirds such as pheasant, grouse, partridge and quail. Halušky, Halushky are the national dish of many Slavic nations. Halušky dumplings are made from a batter consisting of flour and grated potatoes. ''Bryndzové halušky'' are associated to Slovakia, Slovak cuisine in particular. In Germany, Northern Europe, Northern (Finland, Latvia and especially Scandinavia, Scandinavian countries), Eastern Europe (Russia, Belarus and Ukraine) and Poland, newly harvested, early ripening varieties are considered a special delicacy. Boiled whole and served un-peeled with dill, these "new potatoes" are traditionally consumed with pickled herring, Baltic herring. Puddings made from grated potatoes (kugel, kugelis, and potato babka) are popular items of Ashkenazi cuisine, Ashkenazi, Lithuanian cuisine, Lithuanian, and Belarusian cuisine, Belarusian cuisine. German fries, German fried potatoes and various versions of Potato salad are part of German cuisine. Bauernfrühstück (literally ''farmer's breakfast'') is a warm German dish made from fried potatoes, Egg (food), eggs, ham and vegetables. Cepelinai is Lithuanian national dish. They are a type of dumpling made from grated raw potatoes boiled in water and usually stuffed with Ground meat, minced meat, although sometimes dry cottage cheese (curd) or mushrooms are used instead. In Western Europe, especially in Belgium, sliced potatoes are fried to create ''frieten'', the original French fried potatoes. ''Stamppot'', a traditional Dutch meal, is based on mashed potatoes mixed with vegetables. In France, the most notable potato dish is the ''Hachis Parmentier'', named after Antoine-Augustin Parmentier, a French pharmacist, nutritionist, and agronomist who, in the late 18th century, was instrumental in the acceptance of the potato as an edible crop in the country. ''Pâté aux pommes de terre'' is a regional potato dish from the central Allier and Limousin (region), Limousin regions. ''Gratin dauphinois'', consisting of baked thinly sliced potatoes with cream or milk, and ''tartiflette'', with Reblochon cheese, are also widespread. In the north of Italy, in particular, in the Friuli region of the northeast, potatoes serve to make a type of pasta called gnocchi. Similarly, cooked and mashed potatoes or potato flour can be used in the Knödel or dumpling eaten with or added to meat dishes all over central and Eastern Europe, but especially in Bavaria and Luxembourg. Potatoes form one of the main ingredients in many soups such as the vichyssoise and Albanian potato and cabbage soup. In western Norway, komle is popular. A traditional Canary Islands dish is Canarian wrinkly potatoes or ''papas arrugadas''. ''Tortilla de patatas'' (potato omelette) and ''patatas bravas'' (a dish of fried potatoes in a spicy tomato sauce) are near-universal constituent of Spanish tapas.


North America

In the US, potatoes have become one of the most widely consumed crops and thus have a variety of preparation methods and condiments. French fries and often hash browns are commonly found in typical American fast-food burger "joints" and cafeterias. One popular favourite involves a baked potato with cheddar cheese (or sour cream and chives) on top, and in New England "smashed potatoes" (a chunkier variation on mashed potatoes, retaining the peel) have a great popularity. Potato flakes are popular as an instant variety of mashed potatoes, which reconstitute into mashed potatoes by adding water, with butter or oil and salt to taste. A regional dish of Central New York, salt potatoes are bite-size new potatoes boiled in water saturated with salt then served with melted butter. At more formal dinners, a common practice includes taking small red potatoes, slicing them, and roasting them in an iron skillet. Among American Jews, the practice of eating latkes (fried potato pancakes) is common during the festival of Hanukkah. A traditional Acadian dish from New Brunswick is known as ''poutine râpée''. The Acadian poutine is a ball of grated and mashed potato, salted, sometimes filled with pork in the centre, and boiled. The result is a moist ball about the size of a baseball (ball), baseball. It is commonly eaten with salt and pepper or brown sugar. It is believed to have originated from the German ''Klöße'', prepared by early German settlers who lived among the Acadians. ''Poutine'', by contrast, is a hearty serving of French fries, fresh cheese curds and hot gravy. Tracing its origins to Quebec in the 1950s, it has become a widespread and popular dish throughout Canada. Potato grading for Idaho potatoes is performed in which No. 1 potatoes are the highest quality and No. 2 are rated as lower in quality due to their appearance (e.g. blemishes or bruises, pointy ends). Potato density assessment can be performed by floating them in brines. High-density potatoes are desirable in the production of dehydrated mashed potatoes, potato crisps and french fries. File:Burger and fries (1).jpg, French fries served with a hamburger File:OriginalPoutineLaBanquise.jpg, Poutine, a Canadian dish of fried potatoes, cheese curds, and gravy


South Asia

In South Asia, the potato is a very popular traditional staple. In India, the most popular potato dishes are ''aloo ki sabzi'', batata vada, and samosa, which is spicy mashed potato mixed with a small amount of vegetable stuffed in conical dough, and deep fried. Potatoes are also a major ingredient as fast food items, such as aloo chaat, where they are deep fried and served with chutney. In Northern India, alu dum and alu paratha are a favourite part of the diet; the first is a spicy curry of boiled potato, the second is a type of stuffed chapati. A dish called masala dosa from South India is very notable all over India. It is a thin pancake of rice and legume, pulse batter rolled over spicy smashed potato and eaten with sambhar and chutney. Poori in south India in particular in Tamil Nadu is almost always taken with smashed potato masal. Other favourite dishes are alu tikki and pakoda items. Vada pav is a popular vegetarian fast food dish in Mumbai and other regions in the Maharashtra in India. Aloo posto (a curry with potatoes and poppy seeds) is immensely popular in East India, especially Bengal. Although potatoes are not native to India, it has become a vital part of food all over the country especially North Indian food preparations. In Tamil Nadu this tuber acquired a name based on its appearance 'urulai-k-kizhangu' (உருளைக் கிழங்கு) meaning cylindrical tuber. The Aloo gosht, Potato and meat curry, is one of the popular dishes in South Asia, especially in Pakistan.


East Asia

In East Asia, particularly Southeast Asia, rice is by far the predominant starch crop, with potatoes a secondary crop, especially in China and Japan. However, it is used in northern China where rice is not easily grown, with a popular dish being (''qīng jiāo tǔ dòu sī''), made with green pepper, vinegar and thin slices of potato. In the winter, roadside sellers in northern China will also sell roasted potatoes. It is also occasionally seen in Korean and Thai cuisines.


Cultural significance


In art

The potato has been an essential crop in the
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made ceramics from the earth, water, and fire. This pottery was a sacred substance, formed in significant shapes and used to represent important themes. Potatoes are represented anthropomorphically as well as naturally. During the late 19th century, numerous images of potato harvesting appeared in European art, including the works of Willem Witsen and Anton Mauve. Van Gogh's 1885 painting ''The Potato Eaters'' portrays a family eating potatoes. Van Gogh said he wanted to depict peasants as they really were. He deliberately chose coarse and ugly models, thinking that they would be natural and unspoiled in his finished work. Jean-François Millet's ''The Potato Harvest'' depicts peasants working in the plains between Barbizon and Chailly. It presents a theme representative of the peasants' struggle for survival. Millet's technique for this work incorporated paste-like pigments thickly applied over a coarsely textured canvas. File:Van-willem-vincent-gogh-die-kartoffelesser-03850.jpg, ''The Potato Eaters'' by Van Gogh, 1885 (Van Gogh Museum) File:Jean-François Millet - The Potato Harvest - Walters 37115.jpg, ''The Potato Harvest'' by Jean-François Millet, 1855 (Walters Art Museum)


In popular culture

Invented in 1949, and marketed and sold commercially by Hasbro in 1952, Mr. Potato Head is an American toy that consists of a plastic potato and attachable plastic parts, such as ears and eyes, to make a face. It was the first toy ever advertised on television.


See also

* Climate change and potatoes * Irish potato candy * List of potato cultivars * List of potato dishes * List of potato museums * Loy (spade), a form of early spade used in Ireland for the cultivation of potatoes * New World crops * Potato battery


Explanatory notes


References


Citations


General sources

* ''Economist''. "Llamas and mash"
''The Economist'' 28 February 2008 online
* ''Economist''. "The potato: Spud we like", (leader
''The Economist'' 28 February 2008 online
* * Hawkes, J.G. (1990). ''The Potato: Evolution, Biodiversity & Genetic Resources'', Smithsonian Institution Press, Washington, DC * * * McNeill, William H. "How the Potato Changed the World's History." ''Social Research'' (1999) 66#1 pp. 67–83. Fulltext: Ebsco, by a leading historian * * Ó Gráda, Cormac. ''Black '47 and Beyond: The Great Irish Famine in History, Economy, and Memory.'' (1999). 272 pp. * Ó Gráda, Cormac, Richard Paping, and Eric Vanhaute, eds. ''When the Potato Failed: Causes and Effects of the Last European Subsistence Crisis, 1845–1850.'' (2007). 342 pp.  . 15 essays by scholars looking at Ireland and all of Europe * Reader, John. ''Propitious Esculent: The Potato in World History'' (2008), 315pp a standard scholarly history * Salaman, Redcliffe N. (1989). ''The History and Social Influence of the Potato'', Cambridge University Press (originally published in 1949; reprinted 1985 with new introduction and corrections by J.G. Hawkes). * Stevenson, W.R., Loria, R., Franc, G.D., and Weingartner, D.P. (2001) ''Compendium of Potato Diseases'', 2nd ed, Amer. Phytopathological Society, St. Paul, MN. * Zuckerman, Larry. ''The Potato: How the Humble Spud Rescued the Western World.'' (1998). 304 pp. Douglas & McIntyre. .


Further reading

* * *
The World Potato Atlas
released by the International Potato Center in 2006 and regularly updated. Includes current chapters of 15 countries: ** South America: (English and Spanish): Bolivia, Colombia, Ecuador, Peru ** Africa: Cameroon, Ethiopia, Kenya ** Eurasia: Armenia, Bangladesh, China, India, Myanmar, Nepal, Pakistan, Tajikistan ** 38 others as brief "archive" chapters ** Further information links a
Other Materials
* World Geography of the Potato a
UGA.edu
released in 1993.
''Atlas of Wild Potatoes''
(2002), Systematic and Ecogeographic Studies on Crop Genepools 10, International Plant Genetic Resources Institute (IPGRI), * Gauldie, Enid (1981). The Scottish Miller 1700–1900. Pub. John Donald. .


External links


''Solanum tuberosum'' (potato, papas): life cycle, tuber anatomy at GeoChemBio
{{Authority control Potatoes, Crops originating from Bolivia Crops originating from indigenous Americans Crops originating from Peru Crops originating from South America Cuisine of Northern Ireland Edible Solanaceae Flora of the Andes Irish cuisine Plants described in 1753 Root vegetables Solanum Staple foods Stoloniferous plants Tubers