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Maize

Maize (/mz/ MAYZ; Zea mays subsp. mays, from Spanish: maíz after Taino: mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago.[2][3] The leafy stalk of the plant produces pollen inflorescences (or "tassels") and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds, which are fruits.[4][5] The term maize is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike corn, which has a complex variety of meanings that vary by context and geographic region.

Maize
Illustration showing male and female maize flowers
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Panicoideae
Genus: Zea
Species:
Z. mays
Binomial name
Zea mays

Maize has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat or rice. In addition to being consumed directly by humans (often in the form of masa), maize is also used for corn ethanol, animal feed and other maize products, such as corn starch and corn syrup.[6] The six major types of maize are dent corn, flint corn, pod corn, popcorn, flour corn, and sweet corn.[7] Sugar-rich varieties called sweet corn are usually grown for human consumption as kernels, while field corn varieties are used for animal feed, various corn-based human food uses (including grinding into cornmeal or masa, pressing into corn oil, fermentation and distillation into alcoholic beverages like bourbon whiskey), and as feedstocks for the chemical industry. Maize is also used in making ethanol and other biofuels.

Maize is widely cultivated throughout the world, and a greater weight of maize is produced each year than any other grain.[8] In 2021, total world production was 1.2 billion tonnes. Maize is the most widely grown grain crop throughout the Americas, with 384 million metric tons grown in the United States alone in 2021.[citation needed] Genetically modified maize made up 85% of the maize planted in the United States in 2009.[9] Subsidies in the United States help to account for its high level of cultivation of maize and its position as the largest producer in the world.[10]

History

Pre-Columbian development

 
Plant fragments dated to 4200 BC found in the Guilá Naquitz Cave in Oaxaca, Mexico, showed maize had already been domesticated from teosinte.[3]
 
Cultivation of maize in an illustration from the 16th c. Florentine Codex

Maize is a cultigen; human intervention is required for it to propagate. Whether or not the kernels fall off the cob on their own is a key piece of evidence used in archaeology to distinguish domesticated maize from its naturally-propagating teosinte ancestor.[3] Genetic evidence can also be used to determine when various lineages split.[11]

Most historians believe maize was domesticated in the Tehuacán Valley of Mexico.[12] Recent research in the early 21st century has modified this view somewhat; scholars now indicate the adjacent Balsas River Valley of south-central Mexico as the center of domestication.[13]

An 2002 study by Matsuoka et al.. has demonstrated that, rather than the multiple independent domestications model, all maize arose from a single domestication in southern Mexico about 9,000 years ago. The study also demonstrated that the oldest surviving maize types are those of the Mexican highlands. Later, maize spread from this region over the Americas along two major paths. This is consistent with a model based on the archaeological record suggesting that maize diversified in the highlands of Mexico before spreading to the lowlands.[14][15]

Archaeologist Dolores Piperno has said:[13]

A large corpus of data indicates that [maize] was dispersed into lower Central America by 7600 BP [5600 BC] and had moved into the inter-Andean valleys of Colombia between 7000 and 6000 BP [5000–4000 BC].

— Dolores Piperno, The Origins of Plant Cultivation and Domestication in the New World Tropics: Patterns, Process, and New Developments[13]

Since then, even earlier dates have been published.[16]

According to a genetic study by the Brazilian Agricultural Research Corporation (Embrapa), corn cultivation was introduced in South America from Mexico, in two great waves: the first, more than 6000 years ago, spread through the Andes. Evidence of cultivation in Peru has been found dating to about 6700 years ago.[17] The second wave, about 2000 years ago, through the lowlands of South America.[18]

The earliest maize plants grew only small, 25-millimetre-long (1 in) corn ears, and only one per plant. In Jackson Spielvogel's view, many centuries of artificial selection (rather than the current view that maize was exploited by interplanting with teosinte) by the indigenous people of the Americas resulted in the development of maize plants capable of growing several ears per plant, which were usually several centimetres/inches long each.[19] The Olmec and Maya cultivated maize in numerous varieties throughout Mesoamerica; they cooked, ground and processed it through nixtamalization. It was believed that beginning about 2500 BC, the crop spread through much of the Americas.[20] Research of the 21st century has established even earlier dates. The region developed a trade network based on surplus and varieties of maize crops.[citation needed]

Mapuches of south-central Chile cultivated maize along with quinoa and potatoes in pre-Hispanic times; however, potato was the staple food of most Mapuches, "specially in the southern and coastal [Mapuche] territories where maize did not reach maturity".[21][22] Before the expansion of the Inca Empire maize was traded and transported as far south as 40°19' S in Melinquina, Lácar Department.[23] In that location maize remains were found inside pottery dated to 730 ± 80 BP and 920 ± 60 BP. Probably this maize was brought across the Andes from Chile.[23] The presence of maize in Guaitecas Archipelago (43°55' S), the southernmost outpost of pre-Hispanic agriculture,[24] is reported by early Spanish explorers.[25] However the Spanish may have misidentified the plant.[25]

By at least 1000 BCE, the Olmec in Mesoamerica had based their calendar, language, myths and worldview with maize at the center of their symbolism.[26]

Columbian exchange

After the arrival of Europeans in 1492, Spanish settlers consumed maize, and explorers and traders carried it back to Europe and introduced it to other countries. Spanish settlers much preferred wheat bread to maize, cassava, or potatoes. Maize flour could not be substituted for wheat for communion bread, since in Christian belief only wheat could undergo transubstantiation and be transformed into the body of Christ.[27] Some Spaniards worried that by eating indigenous foods, which they did not consider nutritious, they would weaken and risk turning into Indians. "In the view of Europeans, it was the food they ate, even more than the environment in which they lived, that gave Amerindians and Spaniards both their distinctive physical characteristics and their characteristic personalities."[28] Despite these worries, Spaniards did consume maize. Archeological evidence from Florida sites indicate they cultivated it as well.[29]

Maize spread to the rest of the world because of its ability to grow in diverse climates. It was cultivated in Spain just a few decades after Columbus's voyages and then spread to Italy, West Africa and elsewhere.[29] Widespread cultivation most likely began in southern Spain in 1525, after which it quickly spread to the rest of the Spanish Empire including its territories in Italy (and, from there, to other Italian states). Maize had many advantages over wheat and barley; it yielded two and a half times the food energy per unit cultivated area,[30] could be harvested in successive years from the same plot of land, and grew in wildly varying altitudes and climates, from relatively dry regions with only 250 mm (10 in) of annual rainfall to damp regions with over 5,000 mm (200 in). By the 17th century it was a common peasant food in Southwestern Europe, including Portugal, Spain, southern France, and Italy. By the 18th century, it was the chief food of the southern French and Italian peasantry, especially in the form of polenta in Italy.[31]

Names

 
Many small male flowers make up the male inflorescence, called the tassel.

The word maize derives from the Spanish form of the indigenous Taíno word for the plant, mahiz.[32] Using the maize common name, Linnaeus included it as the species epithet in Zea mays.[33] It is known by other names including "corn" in some English speaking countries.[34]

Maize is preferred in formal, scientific, and international usage as a common name because it refers specifically to this one grain, unlike corn, which has a complex variety of meanings that vary by context and geographic region.[35] International groups such as the Centre for Agriculture and Bioscience International also consider maize the preferred common name.[36] According to Ohio State University, the US and a handful of other English-speaking countries primarily use corn, but the rest of the world calls this maize or maíz.[37] The word maize is considered interchangeable with corn in the West; during early British and American trade, all grains were considered corn. Maize retained the name corn in the West as the primary grain in these trade relationships.[33]

The word "corn" outside the US, Canada, Australia, and New Zealand is synonymous with grain referring to any cereal crop with its meaning understood to vary geographically to refer to the local staple.[38][35] In the United States,[38] Canada,[39] Australia, and New Zealand,[40] corn primarily means maize; this usage started as a shortening of "Indian corn".[38] "Indian corn" primarily means maize (the staple grain of indigenous Americans), but can refer more specifically to multicolored "flint corn" used for decoration.[41] Other common names include barajovar, makka, silk maize, and zea.[42]

In a 1999 journal article, Betty Fussell describing calling maize as corn was "to plunge into tragi-farcial mistranslations of language and history." Similar to the British, the Spanish referred to maize as panizo, a generic term for cereal grains, as did Italians with the term polenta. The British later referred to maize as Turkey wheat, Turkey corn, or Indian corn with Fusell commenting that "they meant not a place but a condition, a savage rather than a civilized grain", especially with Turkish people later naming it kukuruz, or barbaric.[43]

The word maize is used by agricultural bodies and research institutes such as the UN's FAO,[44] the International Maize and Wheat Improvement Center based out of Mexico, and the Indian Institute of Maize Research.[45] National agricultural and industry associations often include the word maize in their name such as the Maize Association of Australia,[46] and the National Maize Association of Nigeria.[47]

In Southern Africa, maize is commonly called mielie (Afrikaans) or mealie (English), words possibly derived from the Portuguese word for maize, milho, but more probably from Dutch meel or English meal, meaning the edible part of a grain or pulse.[48]

Structure and physiology

The maize plant is often 3 m (10 ft) in height,[49] though some natural strains can grow 13 m (43 ft),[50] and the tallest recorded plant reached almost 14 metres (46 ft).[51] The stem is commonly composed of 20 internodes[52] of 18 cm (7 in) length.[49] The leaves arise from the nodes, alternately on opposite sides on the stalk,[53] and have entire margins.[54]

The apex of the stem ends in the tassel, an inflorescence of male flowers. When the tassel is mature and conditions are suitably warm and dry, anthers on the tassel dehisce and release pollen. Maize pollen is anemophilous (dispersed by wind), and because of its large settling velocity, most pollen falls within a few meters of the tassel.[55]

Ears develop above a few of the leaves in the midsection of the plant, between the stem and leaf sheath, elongating by around 3 mm (18 in) per day, to a length of 18 cm (7 in)[49] with 60 cm (24 in) being the maximum alleged in the subspecies.[56] They are female inflorescences, tightly enveloped by several layers of ear leaves commonly called husks.

Elongated stigmas, called silks, emerge from the whorl of husk leaves at the end of the ear. They are often pale yellow and 18 cm (7 in) in length, like tufts of hair in appearance. At the end of each is a carpel, which may develop into a "kernel" if fertilized by a pollen grain. The pericarp of the fruit is fused with the seed coat referred to as "caryopsis", typical of the grasses, and the entire kernel is often referred to as the "seed". The cob is close to a multiple fruit in structure, except that the individual fruits (the kernels) never fuse into a single mass. The grains are about the size of peas, and adhere in regular rows around a white, pithy substance, which forms the cob. The maximum size of kernels is reputedly 2.5 cm (1 in).[57] An ear commonly holds 600 kernels. They are of various colors: blackish, bluish-gray, purple, green, red, white and yellow. When ground into flour, maize yields more flour with much less bran than wheat does. It lacks the protein gluten of wheat and, therefore, makes baked goods with poor rising capability. A genetic variant that accumulates more sugar and less starch in the ear is consumed as a vegetable and is called sweet corn. Young ears can be consumed raw, with the cob and silk, but as the plant matures (usually during the summer months), the cob becomes tougher and the silk dries to inedibility. By the end of the growing season, the kernels dry out and become difficult to chew without cooking.[58]

Planting density affects multiple aspects of maize. Modern farming techniques in developed countries usually rely on dense planting, which produces one ear per stalk.[59] Stands of silage maize are yet denser,[citation needed] and achieve a lower percentage of ears and more plant matter.[citation needed]

Maize is a facultative short-day plant[60] and flowers in a certain number of growing degree days > 10 °C (50 °F) in the environment to which it is adapted.[61] The magnitude of the influence that long nights have on the number of days that must pass before maize flowers is genetically prescribed[62] and regulated by the phytochrome system.[63] Photoperiodicity can be eccentric in tropical cultivars such that the long days characteristic of higher latitudes allow the plants to grow so tall that they do not have enough time to produce seed before being killed by frost. These attributes, however, may prove useful in using tropical maize for biofuels.[64]

Immature maize shoots accumulate a powerful antibiotic substance, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA). DIMBOA is a member of a group of hydroxamic acids (also known as benzoxazinoids) that serve as a natural defense against a wide range of pests, including insects, pathogenic fungi and bacteria. DIMBOA is also found in related grasses, particularly wheat. A maize mutant (bx) lacking DIMBOA is highly susceptible to attack by aphids and fungi. DIMBOA is also responsible for the relative resistance of immature maize to the European corn borer (family Crambidae). As maize matures, DIMBOA levels and resistance to the corn borer decline.[citation needed]

Because of its shallow roots, maize is susceptible to droughts, intolerant of nutrient-deficient soils, and prone to be uprooted by severe winds.[65]

 
cv. 'Ottofile giallo Tortonese'' – MHNT
 
cv. "strawberry"—MHNT
 
cv. "Oaxacan Green" MHNT
 
Variegated maize ears
 
Multicolored corn kernels (CSIRO)

While yellow maizes derive their color from lutein and zeaxanthin, in red-colored maizes, the kernel coloration is due to anthocyanins and phlobaphenes. These latter substances are synthesized in the flavonoids synthetic pathway[66] from polymerization of flavan-4-ols[67] by the expression of maize pericarp color1 (p1) gene[68] which encodes an R2R3 myb-like transcriptional activator[69] of the A1 gene encoding for the dihydroflavonol 4-reductase (reducing dihydroflavonols into flavan-4-ols)[70] while another gene (Suppressor of Pericarp Pigmentation 1 or SPP1) acts as a suppressor.[71] The p1 gene encodes an Myb-homologous transcriptional activator of genes required for biosynthesis of red phlobaphene pigments, while the P1-wr allele specifies colorless kernel pericarp and red cobs, and unstable factor for orange1 (Ufo1) modifies P1-wr expression to confer pigmentation in kernel pericarp, as well as vegetative tissues, which normally do not accumulate significant amounts of phlobaphene pigments.[68] The maize P gene encodes a Myb homolog that recognizes the sequence CCT/AACC, in sharp contrast with the C/TAACGG bound by vertebrate Myb proteins.[72]

The ear leaf is the leaf most closely associated with a particular developing ear. This leaf and above contribute 70%[73] to 75% to 90%[74] of grain fill. Therefore fungicide application is most important in that region in most disease environments.[73][74]

Abnormal flowers

Maize flowers may sometimes exhibit mutations that lead to the formation of female flowers in the tassel. These mutations, ts4 and Ts6, prohibit the development of the stamen while simultaneously promoting pistil development.[75] This may cause inflorescences containing both male and female flowers, or hermaphrodite flowers.[76]

Genomics and genetics

 
Exotic varieties are collected to add genetic diversity when selectively breeding new domestic strains
 
With white and yellow kernels

Maize is an annual grass in the family Gramineae, which includes such plants as wheat, rye, barley, rice, sorghum, and sugarcane. There are two major species of the genus Zea (out of six total): Z. mays (maize) and Z. diploperennis, which is a perennial type of teosinte. The annual teosinte variety called Z. m. mexicana is the closest botanical relative to maize. It still grows in the wild as an annual in Mexico and Guatemala.[77]

Many forms of maize are used for food, sometimes classified as various subspecies related to the amount of starch each has:

This system has been replaced (though not entirely displaced) over the last 60 years by multivariable classifications based on ever more data. Agronomic data were supplemented by botanical traits for a robust initial classification, then genetic, cytological, protein and DNA evidence was added. Now, the categories are forms (little used), races, racial complexes, and recently branches.[citation needed]

Maize is a diploid with 20 chromosomes (n=10). The combined length of the chromosomes is 1500 cM. Some of the maize chromosomes have what are known as "chromosomal knobs": highly repetitive heterochromatic domains that stain darkly. Individual knobs are polymorphic among strains of both maize and teosinte.[citation needed] Hufford et al., 2012 finds that 83% of allelic variation within the genome derives from its teosinte ancestors, primarily due to the freedom of Zeas to outcross.[78]

Barbara McClintock used these knob markers to validate her transposon theory of "jumping genes", for which she won the 1983 Nobel Prize in Physiology or Medicine. Maize is still an important model organism for genetics and developmental biology today.[79]

The centromeres have two types of structural components, both of which are found only in the centromeres: Large arrays of CentC, a short satellite DNA; and a few of a family of retrotransposons. The B chromosome, unlike the others, contains an additional repeat which extends into neighboring areas of the chromosome. Centromeres can accidentally shrink during division and still function, although it is thought this will fail if it shrinks below a few hundred kilobase. Kinetochores contain RNA originating from centromeres. Centromere regions can become inactive, and can continue in that state if the chromosome still has another active one.[80]

The Maize Genetics Cooperation Stock Center, funded by the USDA Agricultural Research Service and located in the Department of Crop Sciences at the University of Illinois at Urbana-Champaign, is a stock center of maize mutants. The total collection has nearly 80,000 samples. The bulk of the collection consists of several hundred named genes, plus additional gene combinations and other heritable variants. There are about 1000 chromosomal aberrations (e.g., translocations and inversions) and stocks with abnormal chromosome numbers (e.g., tetraploids). Genetic data describing the maize mutant stocks as well as myriad other data about maize genetics can be accessed at MaizeGDB, the Maize Genetics and Genomics Database.[81]

In 2005, the US National Science Foundation (NSF), Department of Agriculture (USDA) and the Department of Energy (DOE) formed a consortium to sequence the B73 maize genome. The resulting DNA sequence data was deposited immediately into GenBank, a public repository for genome-sequence data. Sequences and genome annotations have also been made available throughout the project's lifetime at the project's official site.[82]

Primary sequencing of the maize genome was completed in 2008.[83] On November 20, 2009, the consortium published results of its sequencing effort in Science.[84] The genome, 85% of which is composed of transposons, was found to contain 32,540 genes (By comparison, the human genome contains about 2.9 billion bases and 26,000 genes). Much of the maize genome has been duplicated and reshuffled by helitrons—group of rolling circle transposons.[85]

In Z. mays and various other angiosperms the MADS-box motif is involved in floral development. Early study in several angiosperm models including Z. mays was the beginning of research into the molecular evolution of floral structure in general, as well as their role in nonflowering plants.[86]

Varieties differ in their resistance to insects, including borers.[87] CIMMYT maintains a large collection of maize/corn accessions tested and cataloged for insect resistance.[87]

Evolution

As with many plants and animals, Z. mays has a positive correlation between effective population size and the magnitude of selection pressure. Z. m. having an EPS of ~650,000, it clusters with others of about the same EPS, and has 79% of its amino acid sites under selection.[88]

Recombination is a significant source of diversity in Z. mays. (Note that this finding supersedes previous studies which showed no such correlation.)[88]

This recombination/diversity effect is seen throughout plants but is also found to not occur – or not as strongly – in regions of high gene density. This is likely the reason that domesticated Z. mays has not seen as much of an increase in diversity within areas of higher density as in regions of lower density, although there is more evidence in other plants.[88]

Some lines of maize have undergone ancient polyploidy events, starting 11 million years ago. Over that time ~72% of polyploid duplicated genes have been retained, which is higher than other plants with older polyploidy events. Thus maize may be due to lose more duplicate genes as time goes along, similar to the course followed by the genomes of other plants. If so - if gene loss has merely not occurred yet - that could explain the lack of observed positive selection and lower negative selection which are observed in otherwise similar plants, i.e. also naturally outcrossing and with similar effective population sizes.[88]

Ploidy does not appear to influence EPS or magnitude of selection effect in maize.[88]

Breeding

Maize reproduces sexually each year. This randomly selects half the genes from a given plant to propagate to the next generation, meaning that desirable traits found in the crop (like high yield or good nutrition) can be lost in subsequent generations unless certain techniques are used.[citation needed]

Maize breeding in prehistory resulted in large plants producing large ears. Modern breeding began with individuals who selected highly productive varieties in their fields and then sold seed to other farmers. James L. Reid was one of the earliest and most successful developing Reid's Yellow Dent in the 1860s. These early efforts were based on mass selection. Later breeding efforts included ear to row selection (C. G. Hopkins c. 1896), hybrids made from selected inbred lines (G. H. Shull, 1909), and the highly successful double cross hybrids using four inbred lines (D. F. Jones c. 1918, 1922). University supported breeding programs were especially important in developing and introducing modern hybrids.[89] By the 1930s, companies such as Pioneer devoted to production of hybrid maize had begun to influence long-term development. Internationally important seed banks such as the International Maize and Wheat Improvement Center (CIMMYT) and the US bank at the Maize Genetics Cooperation Stock Center University of Illinois at Urbana-Champaign maintain germplasm important for future crop development.[citation needed]

Since the 1940s the best strains of maize have been first-generation hybrids made from inbred strains that have been optimized for specific traits, such as yield, nutrition, drought, pest and disease tolerance. Both conventional cross-breeding and genetic engineering have succeeded in increasing output and reducing the need for cropland, pesticides, water and fertilizer.[90] There is conflicting evidence to support the hypothesis that maize yield potential has increased over the past few decades. This suggests that changes in yield potential are associated with leaf angle, lodging resistance, tolerance of high plant density, disease/pest tolerance, and other agronomic traits rather than increase of yield potential per individual plant.[91]

Certain varieties of maize have been bred to produce many ears which are the source of the "baby corn" used as a vegetable in Asian cuisine.[92]

CIMMYT operates a conventional breeding program to provide optimized strains. The program began in the 1980s. Hybrid seeds are distributed in Africa by the Drought Tolerant Maize for Africa project.[90]

Genetic engineering

Genetically engineered (GE) maize was one of the 26 GE crops grown commercially in 2016.[93][94] The vast majority of this is Bt maize. Grown since 1997 in the United States and Canada,[95] 92% of the US maize crop was genetically modified in 2016[93][96] and 33% of the worldwide maize crop was GM in 2016.[93][97] As of 2011, Herbicide-tolerant maize varieties were grown in Argentina, Australia, Brazil, Canada, China, Colombia, El Salvador, the European Union, Honduras, Japan, Korea, Malaysia, Mexico, New Zealand, Philippines, the Russian Federation, Singapore, South Africa, Taiwan, Thailand, and the United States. Insect-resistant maize was grown in Argentina, Australia, Brazil, Canada, Chile, China, Colombia, Egypt, the European Union, Honduras, Japan, Korea, Malaysia, Mexico, New Zealand, Philippines, South Africa, Switzerland, Taiwan, the United States, and Uruguay.[98]

In September 2000, up to $50 million worth of food products were recalled due to the presence of Starlink genetically modified corn, which had been approved only for animal consumption and had not been approved for human consumption, and was subsequently withdrawn from the market.[99]

For pest and disease resistance

Tropical landraces remain an important and underused source of resistance alleles for disease and for herbivores. Notable discoveries of rare alleles for this purpose were made by Dao et al., 2014 and Sood et al., 2014.[100] Rashid et al., 2018 use an association mapping panel from CIMMYT originally developed for tropical drought tolerance traits to find new genomic regions providing sorghum downy mildew resistance, and to further characterize SDMR regions already located by others.[101]

Origin

Maize is the domesticated variant of teosinte.[102] The two plants have dissimilar appearance, maize having a single tall stalk with multiple leaves and teosinte being a short, bushy plant. The difference between the two is largely controlled by differences in just two genes, called grassy tillers-1 (gt1, A0A317YEZ1) and teosinte branched-1 (tb1, Q93WI2).[102]

Several theories had been proposed about the specific origin of maize in Mesoamerica:[103][104]

  1. It is a direct domestication of a Mexican annual teosinte, Z. m. ssp. parviglumis, native to the Balsas River valley in south-eastern Mexico,[105] with up to 12% of its genetic material obtained from Z. m. ssp. mexicana through introgression.[14]
  2. It has been derived from hybridization between a small domesticated maize (a slightly changed form of a wild maize) and a teosinte of section Luxuriantes, either Z. luxurians or Z. diploperennis.
  3. It has undergone two or more domestications either of a wild maize or of a teosinte. (The term "teosinte" describes all species and subspecies in the genus Zea, excluding Z. m. ssp. mays.)
  4. It has evolved from a hybridization of Z. diploperennis by Tripsacum dactyloides.

In the late 1930s, Paul Mangelsdorf suggested that domesticated maize was the result of a hybridization event between an unknown wild maize and a species of Tripsacum, a related genus. This theory about the origin of maize has been refuted by modern genetic testing, which refutes Mangelsdorf's model and the fourth listed above.[103]: 40 

The teosinte origin theory was proposed by the Russian botanist Nikolai Ivanovich Vavilov in 1931 and the later American Nobel Prize-winner George Beadle in 1932.[103]: 10  It is supported experimentally and by recent studies of the plants' genomes. Teosinte and maize can cross-breed and produce fertile offspring. A number of questions remain concerning the species, among them:

  1. how the immense diversity of the species of sect. Zea originated,
  2. how the tiny archaeological specimens of 3500–2700 BC could have been selected from a teosinte, and
  3. how domestication could have proceeded without leaving remains of teosinte or maize with teosintoid traits earlier than the earliest known until recently, dating from ca. 1100 BC.

The domestication of maize is of particular interest to researchers—archaeologists, geneticists, ethnobotanists, geographers, etc. The process is thought by some to have started 7,500 to 12,000 years ago. Research from the 1950s to 1970s originally focused on the hypothesis that maize domestication occurred in the highlands between the states of Oaxaca and Jalisco, because the oldest archaeological remains of maize known at the time were found there.

Connection with 'parviglumis' subspecies

 
Teosinte (top), maize-teosinte hybrid (middle), maize (bottom)
 
Ceramic statue of a Maya maize god emerging from an ear of corn, 600–900 A.D.

Genetic studies, published in 2004 by John Doebley, identified Zea mays ssp. parviglumis, native to the Balsas River valley in Mexico's southwestern highlands, and also known as Balsas teosinte, as being the crop wild relative that is genetically most similar to modern maize.[106][105] This was confirmed by further studies, which refined this hypothesis somewhat. Archaeobotanical studies, published in 2009, point to the middle part of the Balsas River valley as the likely location of early domestication; this river is not very long, so these locations are not very distant. Stone milling tools with maize residue have been found in an 8,700 year old layer of deposits in a cave not far from Iguala, Guerrero.[107][108][109]

 
Stucco head of the Maya maize god, 550–850 AD

Doebley was part of the team that first published, in 2002, that maize had been domesticated only once, about 9,000 years ago, and then spread throughout the Americas.[14][110]

A primitive corn was being grown in southern Mexico, Central America, and northern South America 7,000 years ago. Archaeological remains of early maize ears, found at Guila Naquitz Cave in the Oaxaca Valley, date back roughly 6,250 years; the oldest ears from caves near Tehuacan, Puebla, 5,450 B.P.[20]

Maize pollen dated to 7,300 B.P. from San Andres, Tabasco, on the Caribbean coast has also been recovered.[108]

As maize was introduced to new cultures, new uses were developed and new varieties selected to better serve in those preparations. Maize was the staple food, or a major staple – along with squash, Andean region potato, quinoa, beans, and amaranth – of most pre-Columbian North American, Mesoamerican, South American, and Caribbean cultures. The Mesoamerican civilization, in particular, was deeply interrelated with maize. Its traditions and rituals involved all aspects of maize cultivation – from the planting to the food preparation. Maize formed the Mesoamerican people's identity.[citation needed]

It is unknown what precipitated its domestication, because the edible portion of the wild variety is too small, and hard to obtain, to be eaten directly, as each kernel is enclosed in a very hard bivalve shell.[citation needed]

In 1939, George Beadle demonstrated that the kernels of teosinte are readily "popped" for human consumption, like modern popcorn.[111] Some have argued it would have taken too many generations of selective breeding to produce large, compressed ears for efficient cultivation. However, studies of the hybrids readily made by intercrossing teosinte and modern maize suggest this objection is not well founded.[citation needed]

Spreading to the north

Around 4,500 ago, maize began to spread to the north; it was first cultivated in what is now the United States at several sites in New Mexico and Arizona, about 4,100 ago.[112]

During the first millennium AD, maize cultivation spread more widely in the areas north. In particular, the large-scale adoption of maize agriculture and consumption in eastern North America took place about A.D. 900. Native Americans cleared large forest and grassland areas for the new crop.[113]

In 2005, research by the USDA Forest Service suggested that the rise in maize cultivation 500 to 1,000 years ago in what is now the southeastern United States corresponded with a decline of freshwater mussels, which are very sensitive to environmental changes.[114]

Cultivation

Planting

 
Seedlings three weeks after sowing
 
Young stalks

Because it is cold-intolerant, in the temperate zones maize must be planted in the spring. Its root system is generally shallow, so the plant is dependent on soil moisture. As a plant that uses C4 carbon fixation, maize is a considerably more water-efficient crop than plants that use C3 carbon fixation such as alfalfa and soybeans. Maize is most sensitive to drought at the time of silk emergence, when the flowers are ready for pollination. In the United States, a good harvest was traditionally predicted if the maize was "knee-high by the Fourth of July", although modern hybrids generally exceed this growth rate. Maize used for silage is harvested while the plant is green and the fruit immature. Sweet corn is harvested in the "milk stage", after pollination but before starch has formed, between late summer and early to mid-autumn. Field maize is left in the field until very late in the autumn to thoroughly dry the grain, and may, in fact, sometimes not be harvested until winter or even early spring. The importance of sufficient soil moisture is shown in many parts of Africa, where periodic drought regularly causes maize crop failure and consequent famine. Although it is grown mainly in wet, hot climates, it has been said to thrive in cold, hot, dry or wet conditions, meaning that it is an extremely versatile crop.[115]

 
Mature plants showing ears

Maize was planted by the Native Americans in hills, in a complex system known to some as the Three Sisters.[116] Maize provided support for beans, and the beans provided nitrogen derived from nitrogen-fixing rhizobia bacteria which live on the roots of beans and other legumes; and squashes provided ground cover to stop weeds and inhibit evaporation by providing shade over the soil.[117] This method was replaced by single species hill planting where each hill 60–120 cm (2 ft 0 in – 3 ft 11 in) apart was planted with three or four seeds, a method still used by home gardeners. A later technique was "checked maize", where hills were placed 1 m (40 in) apart in each direction, allowing cultivators to run through the field in two directions. In more arid lands, this was altered and seeds were planted in the bottom of 10–12 cm (4–4+12 in) deep furrows to collect water. Modern technique plants maize in rows which allows for cultivation while the plant is young, although the hill technique is still used in the maize fields of some Native American reservations. When maize is planted in rows, it also allows for planting of other crops between these rows to make more efficient use of land space.[118]

In most regions today, maize grown in residential gardens is still often planted manually with a hoe, whereas maize grown commercially is no longer planted manually but rather is planted with a planter. In North America, fields are often planted in a two-crop rotation with a nitrogen-fixing crop, often alfalfa in cooler climates and soybeans in regions with longer summers. Sometimes a third crop, winter wheat, is added to the rotation.[citation needed]

Many of the maize varieties grown in the United States and Canada are hybrids. Often the varieties have been genetically modified to tolerate glyphosate or to provide protection against natural pests. Glyphosate is an herbicide which kills all plants except those with genetic tolerance. This genetic tolerance is very rarely found in nature.[citation needed]

In the midwestern United States, low-till or no-till farming techniques are usually used. In low-till, fields are covered once, maybe twice, with a tillage implement either ahead of crop planting or after the previous harvest. The fields are planted and fertilized. Weeds are controlled through the use of herbicides, and no cultivation tillage is done during the growing season. This technique reduces moisture evaporation from the soil, and thus provides more moisture for the crop. The technologies mentioned in the previous paragraph enable low-till and no-till farming. Weeds compete with the crop for moisture and nutrients, making them undesirable.[citation needed]

Harvesting

 
Mature maize ears
 
Harvesting maize, Jones County, Iowa
 
Harvesting maize, Rantasalmi, South Savonia, Finland
 
Hand-picking harvest of maize in Myanmar

Maize harvested as a grain crop can be kept in the field a relatively long time, even months, after the crop is ready to harvest; it is also harvested and stored in the husk leaves if kept dry.[119] Before the 20th century, all maize harvesting was by manual labour, by grazing, or by some combination of those. Whether the ears were hand-picked and the stover was grazed, or the whole plant was cut, gathered, and shocked, people and livestock did all the work. Between the 1890s and the 1970s, the technology of maize harvesting expanded greatly. Today, all such technologies, from entirely manual harvesting to entirely mechanized, are still in use to some degree, as appropriate to each farm's needs, although the thoroughly mechanized versions predominate, as they offer the lowest unit costs when scaled to large farm operations.

Before World War II, most maize in North America was harvested by hand. This involved a large number of workers and associated social events (husking or shucking bees). From the 1890s onward, some machinery became available to partially mechanize the processes, such as one- and two-row mechanical pickers (picking the ear, leaving the stover) and corn binders, which are reaper-binders designed specifically for maize (for example, Video on YouTube). The latter produce sheaves that can be shocked. By hand or mechanical picker, the entire ear is harvested, which then requires a separate operation of a maize sheller to remove the kernels from the ear. Whole ears of maize were often stored in corn cribs, and these whole ears are a sufficient form for some livestock feeding use. Today corn cribs with whole ears, and corn binders, are less common because most modern farms harvest the grain from the field with a combine and store it in bins. The combine with a corn head (with points and snap rolls instead of a reel) does not cut the stalk; it simply pulls the stalk down. The stalk continues downward and is crumpled into a mangled pile on the ground, where it usually is left to become organic matter for the soil. The ear of maize is too large to pass between slots in a plate as the snap rolls pull the stalk away, leaving only the ear and husk to enter the machinery. The combine separates the husk and the cob, keeping only the kernels.[120]

The entire maize plant is also harvested as a silage crop.[121]

For storing grain in bins, the moisture of the grain must be sufficiently low to avoid spoiling. If the moisture content of the harvested grain is too high, grain dryers are used to reduce the moisture content by blowing heated air through the grain. This can require large amounts of energy in the form of combustible gases (propane or natural gas) and electricity to power the blowers.[122]

Production

 
Production of maize (2019)[123]

Maize is widely cultivated throughout the world, and a greater weight of maize is produced each year than any other grain.[8] In 2020, total world production was 1.16 billion tonnes, led by the United States with 31.0% of the total (table). China produced 22.4% of the global total.[124]

Maize production – 2020[125][124]
Country Production
(millions of tonnes)
  United States 360.3
  China 260.7
  Brazil 104.0
  Argentina 58.4
  Ukraine 30.3
  India 30.2
  Mexico 27.4
  Indonesia 22.5
  South Africa 15.3
  Russia 13.9
 World 1162.4

United States

In 2016, maize production was forecast to be over 380 million metric tons (15 billion bushels), an increase of 11% over 2014 American production.[126] Based on conditions as of August 2016, the expected yield would be the highest ever for the United States.[126] The area of harvested maize was forecast to be 35 million hectares (87 million acres), an increase of 7% over 2015.[126] Maize is especially popular in Midwestern states such as Indiana, Iowa, and Illinois; in the latter, it was named the state's official grain in 2017.[127]

The estimated corn usage for crop year September 1, 2020 to August 31, 2021, was 38.7 percent was used for feed, 34 percent for ethanol, 17.5 percent for export, and 9.8 percent for food.[128]

Trade

Corn futures are traded on several exchanges, the Chicago Board of Trade (CBOT) and JSE Derivatives (JDERIV). The Chicago Board Of Trade sells corn futures with a contact size of 5000 bushels which is quoted in cents/bushel and the JDERIV has a contact size of 100 Tonnes, quoted in Rand/Ton.[129][130] The detailed contract specifications are listed below:

Contract Specifications[129][130]
Corn (CORN) Corn (CNA)
Exchange: JDERIV CBOT
Sector: Grain Grain
Tick Size: 0.2 0.25
Tick Value: 5 ZAR 12.50 USD
BPV: 25 50
Denomination: ZAR USD
Decimal Place: 1 2

Pests

Insects

The susceptibility of maize to the European corn borer and corn rootworms, and the resulting large crop losses which are estimated at a billion dollars worldwide for each pest,[133][134][135] led to the development of transgenics expressing the Bacillus thuringiensis toxin. "Bt maize" is widely grown in the United States and has been approved for release in Europe.

Diseases

Storage

Drying is vital to prevent or at least reduce mycotoxin contamination. Aspergillus and Fusarium spp. are the most common mycotoxin sources, but there are others. Altogether maize contaminants are so common, and this crop is so economically important, that maize mycotoxins are among the most important in agriculture in general.[95]

Uses

Human food

 
Semi-peeled corn on the cob
 
Poster showing a woman serving muffins, pancakes, and grits, with canisters on the table labeled corn meal, grits, and hominy, US Food Administration, 1918

Maize and cornmeal (ground dried maize) constitute a staple food in many regions of the world. Maize is used to produce cornstarch, a common ingredient in home cooking and many industrialized food products. Maize starch can be hydrolyzed and enzymatically treated to produce syrups, particularly high fructose corn syrup, a sweetener; and also fermented and distilled to produce grain alcohol. Grain alcohol from maize is traditionally the source of Bourbon whiskey. Corn flour is used to make cornbread and other baked products.[citation needed]

In prehistoric times Mesoamerican women used a metate to process maize into ground cornmeal, allowing the preparation of foods that were more calorie dense than popcorn. After ceramic vessels were invented the Olmec people began to cook maize together with beans, improving the nutritional value of the staple meal. Although maize naturally contains niacin, an important nutrient, it was not bioavailable without the process of nixtamalization. The Maya used nixtamal meal to make varieties of porridges and tamales.[138] The process was later used in the cuisine of the American South to prepare corn for grits and hominy.[citation needed]

Maize is a staple of Mexican cuisine. Masa (cornmeal treated with limewater) is the main ingredient for tortillas, atole and many other dishes of Central American food. It is the main ingredient of corn tortilla, tamales, pozole, atole and all the dishes based on them, like tacos, quesadillas, chilaquiles, enchiladas, tostadas and many more. In Mexico the fungus of maize, known as huitlacoche, is considered a delicacy.[citation needed]

 
Mexican tamales made with corn meal
 
Boiled corn on a white plate

Coarse maize meal is made into a thick porridge in many cultures: from the polenta of Italy, the angu of Brazil, the mămăligă of Romania, to cornmeal mush in the US (or hominy grits in the South) or the food called mieliepap in South Africa and sadza, nshima, ugali and other names in other parts of Africa. Introduced into Africa by the Portuguese in the 16th century, maize has become Africa's most important staple food crop.[139] These are commonly eaten in the Southeastern United States, foods handed down from Native Americans, who called the dish sagamite.[citation needed]

Maize can also be harvested and consumed in the unripe state, when the kernels are fully grown but still soft. Unripe maize must usually be cooked to become palatable; this may be done by simply boiling or roasting the whole ears and eating the kernels right off the cob. Sweet corn, a genetic variety that is high in sugars and low in starch, is usually consumed in the unripe state. Such corn on the cob is a common dish in the United States, Canada, United Kingdom, Cyprus, some parts of South America, and the Balkans, but virtually unheard of in some European countries.[citation needed] Corn on the cob was hawked on the streets of early 19th-century New York City by poor, barefoot "Hot Corn Girls", who were thus the precursors of hot dog carts, churro wagons, and fruit stands seen on the streets of big cities today.[140]

Within the United States, the usage of maize for human consumption constitutes only around 1/40th of the amount grown in the country. In the United States and Canada, maize is mostly grown to feed livestock, as forage, silage (made by fermentation of chopped green cornstalks), or grain. Maize meal is also a significant ingredient of some commercial animal food products.[citation needed]

Nutritional value

Sweetcorn, yellow, raw
(seeds only)
Note: assuming freed niacin
Nutritional value per 100 g (3.5 oz)
Energy360 kJ (86 kcal)
18.7 g
Starch5.7 g
Sugars6.26 g
Dietary fiber2 g
1.35 g
3.27 g
Tryptophan0.023 g
Threonine0.129 g
Isoleucine0.129 g
Leucine0.348 g
Lysine0.137 g
Methionine0.067 g
Cystine0.026 g
Phenylalanine0.150 g
Tyrosine0.123 g
Valine0.185 g
Arginine0.131 g
Histidine0.089 g
Alanine0.295 g
Aspartic acid0.244 g
Glutamic acid0.636 g
Glycine0.127 g
Proline0.292 g
Serine0.153 g
VitaminsQuantity
%DV
Vitamin A equiv.
1%
9 μg
644 μg
Thiamine (B1)
13%
0.155 mg
Riboflavin (B2)
5%
0.055 mg
Niacin (B3)
12%
1.77 mg
Pantothenic acid (B5)
14%
0.717 mg
Vitamin B6
7%
0.093 mg
Folate (B9)
11%
42 μg
Vitamin C
8%
6.8 mg
MineralsQuantity
%DV
Iron
4%
0.52 mg
Magnesium
10%
37 mg
Manganese
8%
0.163 mg
Phosphorus
13%
89 mg
Potassium
6%
270 mg
Zinc
5%
0.46 mg
Other constituentsQuantity
Water75.96 g

Link to USDA Database entry
One ear of medium size (6-3/4" to 7-1/2" long)
maize has 90 grams of seeds
Percentages are roughly approximated using US recommendations for adults.
Source: USDA FoodData Central

Raw, yellow, sweet maize kernels are composed of 76% water, 19% carbohydrates, 3% protein, and 1% fat (table). In a 100-gram serving, maize kernels provide 86 calories and are a good source (10–19% of the Daily Value) of the B vitamins, thiamin, niacin (but see Pellagra warning below), pantothenic acid (B5) and folate (right table for raw, uncooked kernels, USDA Nutrient Database). In moderate amounts, they also supply dietary fiber and the essential minerals, magnesium and phosphorus whereas other nutrients are in low amounts (table).[citation needed]

Maize has suboptimal amounts of the essential amino acids tryptophan and lysine, which accounts for its lower status as a protein source.[141] However, the proteins of beans and legumes complement those of maize.[141]

Feed and fodder for livestock

Maize is a major source of both grain feed and fodder for livestock. It is fed to the livestock in various ways. When it is used as a grain crop, the dried kernels are used as feed. They are often kept on the cob for storage in a corn crib, or they may be shelled off for storage in a grain bin. The farm that consumes the feed may produce it, purchase it on the market, or some of both. When the grain is used for feed, the rest of the plant (the corn stover) can be used later as fodder, bedding (litter), or soil amendment. When the whole maize plant (grain plus stalks and leaves) is used for fodder, it is usually chopped all at once and ensilaged, as digestibility and palatability are higher in the ensilaged form than in the dried form. Maize silage is one of the most valuable forages for ruminants.[142] Before the advent of widespread ensilaging, it was traditional to gather the corn into shocks after harvesting, where it dried further. With or without a subsequent move to the cover of a barn, it was then stored for weeks to several months until fed to the livestock. Today ensilaging can occur not only in siloes but also in silage wrappers. However, in the tropics, maize can be harvested year-round and fed as green forage to the animals.[143]

Chemicals

Starch from maize can also be made into plastics, fabrics, adhesives, and many other chemical products.[citation needed]

The corn steep liquor, a plentiful watery byproduct of maize wet milling process, is widely used in the biochemical industry and research as a culture medium to grow many kinds of microorganisms.[144]

Chrysanthemin is found in purple corn and is used as a food coloring.[citation needed]

Bio-fuel

"Feed maize" is being used increasingly for heating;[145] specialized corn stoves (similar to wood stoves) are available and use either feed maize or wood pellets to generate heat. Maize cobs are also used as a biomass fuel source. Maize is relatively cheap and home-heating furnaces have been developed which use maize kernels as a fuel. They feature a large hopper that feeds the uniformly sized maize kernels (or wood pellets or cherry pits) into the fire.[citation needed]

Maize is increasingly used as a feedstock for the production of ethanol fuel.[146] When considering where to construct an ethanol plant, one of the site selection criteria is to ensure there is locally available feedstock.[147] Ethanol is mixed with gasoline to decrease the amount of pollutants emitted when used to fuel motor vehicles. High fuel prices in mid-2007 led to higher demand for ethanol, which in turn led to higher prices paid to farmers for maize. This led to the 2007 harvest being one of the most profitable maize crops in modern history for farmers. Because of the relationship between fuel and maize, prices paid for the crop now tend to track the price of oil.[citation needed]

The price of food is affected to a certain degree by the use of maize for biofuel production. The cost of transportation, production, and marketing are a large portion (80%) of the price of food in the United States. Higher energy costs affect these costs, especially transportation. The increase in food prices the consumer has been seeing is mainly due to the higher energy cost. The effect of biofuel production on other food crop prices is indirect. Use of maize for biofuel production increases the demand, and therefore price of maize. This, in turn, results in farm acreage being diverted from other food crops to maize production. This reduces the supply of the other food crops and increases their prices.[148][149]

 
Farm-based maize silage digester located near Neumünster in Germany, 2007. Green inflatable biogas holder is shown on top of the digester.

Maize is widely used in Germany as a feedstock for biogas plants. Here the maize is harvested, shredded then placed in silage clamps from which it is fed into the biogas plants. This process makes use of the whole plant rather than simply using the kernels as in the production of fuel ethanol.[citation needed]

A biomass gasification power plant in Strem near Güssing, Burgenland, Austria, began in 2005. There is potential that diesel can be created from the biogas by the Fischer Tropsch method.[150]

Increasingly, ethanol is being used at low concentrations (10% or less) as an additive in gasoline (gasohol) for motor fuels to increase the octane rating, lower pollutants, and reduce petroleum use (what is nowadays also known as "biofuels" and has been generating an intense debate regarding the human beings' necessity of new sources of energy, on the one hand, and the need to maintain, in regions such as Latin America, the food habits and culture which has been the essence of civilizations such as the one originated in Mesoamerica; the entry, January 2008, of maize among the commercial agreements of NAFTA has increased this debate, considering the bad labor conditions of workers in the fields, and mainly the fact that NAFTA "opened the doors to the import of maize from the United States, where the farmers who grow it receive multimillion-dollar subsidies and other government supports. ... According to OXFAM UK, after NAFTA went into effect, the price of maize in Mexico fell 70% between 1994 and 2001. The number of farm jobs dropped as well: from 8.1 million in 1993 to 6.8 million in 2002. Many of those who found themselves without work were small-scale maize growers.").[151] However, introduction in the northern latitudes of the US of tropical maize for biofuels, and not for human or animal consumption, may potentially alleviate this.[citation needed]

Commodity

Maize is bought and sold by investors and price speculators as a tradable commodity using corn futures contracts. These "futures" are traded on the Chicago Board of Trade (CBOT) under ticker symbol C. They are delivered every year in March, May, July, September, and December.[152]

Ornamental and other uses

Some forms of the plant are occasionally grown for ornamental use in the garden. For this purpose, variegated and colored leaf forms as well as those with colorful ears are used.[citation needed]

Corncobs can be hollowed out and treated to make inexpensive smoking pipes, first manufactured in the United States in 1869.[citation needed]

 
Children playing in a maize kernel box

An unusual use for maize is to create a "corn maze" (or "maize maze") as a tourist attraction. The idea of a maize maze was introduced by the American Maze Company who created a maze in Pennsylvania in 1993.[153][better source needed] Traditional mazes are most commonly grown using yew hedges, but these take several years to mature. The rapid growth of a field of maize allows a maze to be laid out using GPS at the start of a growing season and for the maize to grow tall enough to obstruct a visitor's line of sight by the start of the summer. In Canada and the US, these are popular in many farming communities.[citation needed]

Maize kernels can be used in place of sand in a sandboxlike enclosure for children's play.[154]

Stigmas from female maize flowers, popularly called corn silk, are sold as herbal supplements.[citation needed]

Maize is used as a fish bait, called "dough balls". It is particularly popular in Europe for coarse fishing.[citation needed]

Additionally, feed corn is sometimes used by hunters to bait animals such as deer or wild hogs.[citation needed]

United States usage breakdown

The breakdown of usage of the 12.1-billion-bushel (307-million-tonne) 2008 US maize crop was as follows, according to the World Agricultural Supply and Demand Estimates Report by the USDA.[155]

Use Amount
million bushels million tonnes percentage
livestock feed 5,250 133.4 43.4
ethanol production 3,650 92.7 30.2
exports 1,850 47.0 15.3
production of starch, corn oil, sweeteners (HFCS, etc.) 943 24.0 7.8
human consumption—grits, corn flour, corn meal, beverage alcohol 327 8.3 2.7

In the US since 2009/2010, maize feedstock use for ethanol production has somewhat exceeded direct use for livestock feed; maize use for fuel ethanol was 5,130 million bushels (130 million tonnes) in the 2013/2014 marketing year.[156]

A fraction of the maize feedstock dry matter used for ethanol production is usefully recovered as DDGS (dried distillers grains with solubles). In the 2010/2011 marketing year, about 29.1 million tonnes of DDGS were fed to US livestock and poultry.[157] Because starch utilization in fermentation for ethanol production leaves other grain constituents more concentrated in the residue, the feed value per kg of DDGS, with regard to ruminant-metabolizable energy and protein, exceeds that of the grain. Feed value for monogastric animals, such as swine and poultry, is somewhat lower than for ruminants.[157]

Comparison to other staple foods

The following table shows the nutrient content of maize and major staple foods in a raw harvested form on a dry weight basis to account for their different water contents. Raw forms are not edible and cannot be digested. These must be sprouted, or prepared and cooked for human consumption. In sprouted or cooked form, the relative nutritional and anti-nutritional contents of each of these staples are different from that of raw form of these staples reported in the table below.

Note: niacin for maize assumes freed niacin.
Nutrient content of 10 major staple foods per 100 g dry weight[162]
Staple Maize (corn)[A] Rice, white[B] Wheat[C] Potatoes[D] Cassava[E] Soybeans, green[F] Sweet potatoes[G] Yams[Y] Sorghum[H] Plantain[Z] RDA
Water content (%) 10 12 13 79 60 68 77 70 9 65
Raw grams per 100 g dry weight 111 114 115 476 250 313 435 333 110 286
Nutrient
Energy (kJ) 1698 1736 1574 1533 1675 1922 1565 1647 1559 1460 8,368–10,460
Protein (g) 10.4 8.1 14.5 9.5 3.5 40.6 7.0 5.0 12.4 3.7 50
Fat (g) 5.3 0.8 1.8 0.4 0.7 21.6 0.2 0.6 3.6 1.1 44–77
Carbohydrates (g) 82 91 82 81 95 34 87 93 82 91 130
Fiber (g) 8.1 1.5 14.0 10.5 4.5 13.1 13.0 13.7 6.9 6.6 30
Sugar (g) 0.7 0.1 0.5 3.7 4.3 0.0 18.2 1.7 0.0 42.9 minimal
Minerals [A] [B] [C] [D] [E] [F] [G] [Y] [H] [Z] RDA
Calcium (mg) 8 32 33 57 40 616 130 57 31 9 1,000
Iron (mg) 3.01 0.91 3.67 3.71 0.68 11.09 2.65 1.80 4.84 1.71 8
Magnesium (mg) 141 28 145 110 53 203 109 70 0 106 400
Phosphorus (mg) 233 131 331 271 68 606 204 183 315 97 700
Potassium (mg) 319 131 417 2005 678 1938 1465 2720 385 1426 4700
Sodium (mg) 39 6 2 29 35 47 239 30 7 11 1,500
Zinc (mg) 2.46 1.24 3.05 1.38 0.85 3.09 1.30 0.80 0.00 0.40 11
Copper (mg) 0.34 0.25 0.49 0.52 0.25 0.41 0.65 0.60 - 0.23 0.9
Manganese (mg) 0.54 1.24 4.59 0.71 0.95 1.72 1.13 1.33 - - 2.3
Selenium (μg) 17.2 17.2 81.3 1.4 1.8 4.7 2.6 2.3 0.0 4.3 55
Vitamins [A] [B] [C] [D] [E] [F] [G] [Y] [H] [Z] RDA
Vitamin C (mg) 0.0 0.0 0.0 93.8 51.5 90.6 10.4 57.0 0.0 52.6 90
Thiamin (B1) (mg) 0.43 0.08 0.34 0.38 0.23 1.38 0.35 0.37 0.26 0.14 1.2
Riboflavin (B2) (mg) 0.22 0.06 0.14 0.14 0.13 0.56 0.26 0.10 0.15 0.14 1.3
Niacin (B3) (mg) 4.03 1.82 6.28 5.00 2.13 5.16 2.43 1.83 3.22 1.97 16
Pantothenic acid (B5) (mg) 0.47 1.15 1.09 1.43 0.28 0.47 3.48 1.03 - 0.74 5
Vitamin B6 (mg) 0.69 0.18 0.34 1.43 0.23 0.22 0.91 0.97 - 0.86 1.3
Folate Total (B9) (μg) 21 9 44 76 68 516 48 77 0 63 400
Vitamin A (IU) 238 0 10 10 33 563 4178 460 0 3220 5000
Vitamin E, alpha-tocopherol (mg) 0.54 0.13 1.16 0.05 0.48 0.00 1.13 1.30 0.00 0.40 15
Vitamin K1 (μg) 0.3 0.1 2.2 9.0 4.8 0.0 7.8 8.7 0.0 2.0 120
Beta-carotene (μg) 108 0 6 5 20 0 36996 277 0 1306 10500
Lutein+zeaxanthin (μg) 1506 0 253 38 0 0 0 0 0 86 6000
Fats [A] [B] [C] [D] [E] [F] [G] [Y] [H] [Z] RDA
Saturated fatty acids (g) 0.74 0.20 0.30 0.14 0.18 2.47 0.09 0.13 0.51 0.40 minimal
Monounsaturated fatty acids (g) 1.39 0.24 0.23 0.00 0.20 4.00 0.00 0.03 1.09 0.09 22–55
Polyunsaturated fatty acids (g) 2.40 0.20 0.72 0.19 0.13 10.00 0.04 0.27 1.51 0.20 13–19
[A] [B] [C] [D] [E] [F] [G] [Y] [H] [Z] RDA

A raw yellow dent corn
B raw unenriched long-grain white rice
C raw hard red winter wheat
D raw potato with flesh and skin
E raw cassava
F raw green soybeans
G raw sweet potato
H raw sorghum
Y raw yam
Z raw plantains
/* unofficial

Hazards

Pellagra

When maize was first introduced into farming systems other than those used by traditional native-American peoples, it was generally welcomed with enthusiasm for its productivity. However, a widespread problem of malnutrition soon arose wherever maize was introduced as a staple food. This was a mystery, since these types of malnutrition were not normally seen among the indigenous Americans, for whom maize was the principal staple food.[163]

It was eventually discovered that the indigenous Americans had learned to soak maize in alkali — water (the process now known as nixtamalization) — made with ashes and lime (calcium oxide) since at least 1200–1500 BC by Mesoamericans. They did this to liberate the corn hulls, but (unbeknownst to natives or colonists) it coincidentally liberates the B-vitamin niacin, the lack of which was the underlying cause of the condition known as pellagra.[164]

Maize was introduced into the diet of non-indigenous Americans without the necessary cultural knowledge acquired over thousands of years in the Americas. In the late 19th century, pellagra reached epidemic proportions in parts of the southern US, as medical researchers debated two theories for its origin: the deficiency theory (which was eventually shown to be true) said that pellagra was due to a deficiency of some nutrient, and the germ theory said that pellagra was caused by a germ transmitted by stable flies. A third theory, promoted by the eugenicist Charles Davenport, held that people only contracted pellagra if they were susceptible to it due to certain "constitutional, inheritable" traits of the affected individual.[165]

Once alkali processing and dietary variety were understood and applied, pellagra disappeared in the developed world. The development of high lysine maize and the promotion of a more balanced diet have also contributed to its demise. Pellagra still exists today in food-poor areas and refugee camps where people survive on donated maize.[166]

Allergy

Maize contains lipid transfer protein, an indigestible protein that survives cooking. This protein has been linked to a rare and understudied allergy to maize in humans.[167] The allergic reaction can cause skin rash, swelling or itching of mucous membranes, diarrhea, vomiting, asthma and, in severe cases, anaphylaxis. It is unclear how common this allergy is in the general population.[citation needed]

The Z. mays plant has an OPALS allergy scale rating of 5 out of 10, indicating moderate potential to cause allergic reactions, exacerbated by over-use of the same plant throughout a garden. Corn pollen is heavy, large, and usually airborne in the early morning.[168]

Mycotoxins

Fungicide application does not reduce fungal growth or mycotoxin dramatically, although it can be a part of a successful reduction strategy. Among the most common toxins are those produced by Aspergillus and Fusarium spp. The most common toxins are aflatoxins, fumonisins, zearalenone, and ochratoxin A. Bt maize discourages insect vectors and by so doing it dramatically reduces concentrations of fumonisins, significantly reduces aflatoxins, but only mildly reduces others.[95]

Art

 
Gold maize. Moche culture 300 A.D., Larco Museum, Lima, Peru
 
Water tower in Rochester, Minnesota being painted as an ear of maize

Maize has been an essential crop in the Andes since the pre-Columbian era. The Moche culture from Northern Peru made ceramics from earth, water, and fire. This pottery was a sacred substance, formed in significant shapes and used to represent important themes. Maize was represented anthropomorphically as well as naturally.[169]

In the United States, maize ears along with tobacco leaves are carved into the capitals of columns in the United States Capitol building. Maize itself is sometimes used for temporary architectural detailing when the intent is to celebrate the fall season, local agricultural productivity and culture. Bundles of dried maize stalks are often displayed along with pumpkins, gourds and straw in autumnal displays outside homes and businesses. A well-known example of architectural use is the Corn Palace in Mitchell, South Dakota, which uses cobs and ears of colored maize to implement a mural design that is recycled annually. Another well-known example is the Field of Corn sculpture in Dublin, Ohio, where hundreds of concrete ears of corn stand in a grassy field.[170]

A maize stalk with two ripe ears is depicted on the reverse of the Croatian 1 lipa coin, minted since 1993.[171]

See also

References

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Further reading

  • Aureliano Brandolni; Andrea Brandolini (2006). . Bergamo, Italy: CRF press. Archived from the original on May 31, 2009. Retrieved March 14, 2009. XII+370 pages and 80 colour pages
  • Byerlee, Derek. "The globalization of hybrid maize, 1921–70." Journal of Global History 15.1 (2020): 101–122.
  • Clampitt, Cynthia. Maize: How Corn Shaped the U.S. Heartland (2015)
  • Ferro, D.N. & Weber, D.C. "Managing Sweet Corn Pests in Massachusetts".
  • Bonavia, Duccio (May 13, 2013). Maize: Origin, Domestication, and Its Role in the Development of Culture. Cambridge University Press. ISBN 978-1-107-02303-1.

External links

maize, confused, with, maze, this, article, about, commonly, grown, cereal, grain, other, uses, disambiguation, corn, redirects, here, other, uses, corn, disambiguation, mayz, mays, subsp, mays, from, spanish, maíz, after, taino, mahiz, also, known, corn, nort. Not to be confused with Maze This article is about the commonly grown cereal grain For other uses see Maize disambiguation Corn redirects here For other uses see Corn disambiguation Maize m eɪ z MAYZ Zea mays subsp mays from Spanish maiz after Taino mahiz also known as corn North American and Australian English is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10 000 years ago 2 3 The leafy stalk of the plant produces pollen inflorescences or tassels and separate ovuliferous inflorescences called ears that when fertilized yield kernels or seeds which are fruits 4 5 The term maize is preferred in formal scientific and international usage as a common name because it refers specifically to this one grain unlike corn which has a complex variety of meanings that vary by context and geographic region MaizeIllustration showing male and female maize flowersConservation statusLeast Concern IUCN 3 1 1 Scientific classificationKingdom PlantaeClade TracheophytesClade AngiospermsClade MonocotsClade CommelinidsOrder PoalesFamily PoaceaeSubfamily PanicoideaeGenus ZeaSpecies Z maysBinomial nameZea maysL Maize has become a staple food in many parts of the world with the total production of maize surpassing that of wheat or rice In addition to being consumed directly by humans often in the form of masa maize is also used for corn ethanol animal feed and other maize products such as corn starch and corn syrup 6 The six major types of maize are dent corn flint corn pod corn popcorn flour corn and sweet corn 7 Sugar rich varieties called sweet corn are usually grown for human consumption as kernels while field corn varieties are used for animal feed various corn based human food uses including grinding into cornmeal or masa pressing into corn oil fermentation and distillation into alcoholic beverages like bourbon whiskey and as feedstocks for the chemical industry Maize is also used in making ethanol and other biofuels Maize is widely cultivated throughout the world and a greater weight of maize is produced each year than any other grain 8 In 2021 total world production was 1 2 billion tonnes Maize is the most widely grown grain crop throughout the Americas with 384 million metric tons grown in the United States alone in 2021 citation needed Genetically modified maize made up 85 of the maize planted in the United States in 2009 9 Subsidies in the United States help to account for its high level of cultivation of maize and its position as the largest producer in the world 10 Contents 1 History 1 1 Pre Columbian development 1 2 Columbian exchange 2 Names 3 Structure and physiology 3 1 Abnormal flowers 4 Genomics and genetics 5 Evolution 6 Breeding 6 1 Genetic engineering 6 2 For pest and disease resistance 7 Origin 7 1 Connection with parviglumis subspecies 7 2 Spreading to the north 8 Cultivation 8 1 Planting 8 2 Harvesting 9 Production 9 1 United States 9 2 Trade 10 Pests 10 1 Insects 10 2 Diseases 10 3 Storage 11 Uses 11 1 Human food 11 2 Nutritional value 11 3 Feed and fodder for livestock 11 4 Chemicals 11 5 Bio fuel 11 6 Commodity 11 7 Ornamental and other uses 11 8 United States usage breakdown 12 Comparison to other staple foods 13 Hazards 13 1 Pellagra 13 2 Allergy 13 3 Mycotoxins 14 Art 15 See also 16 References 17 Further reading 18 External linksHistoryPre Columbian development Plant fragments dated to 4200 BC found in the Guila Naquitz Cave in Oaxaca Mexico showed maize had already been domesticated from teosinte 3 Cultivation of maize in an illustration from the 16th c Florentine Codex Ancient Mesoamerican relief National Museum of Anthropology of Mexico Maize is a cultigen human intervention is required for it to propagate Whether or not the kernels fall off the cob on their own is a key piece of evidence used in archaeology to distinguish domesticated maize from its naturally propagating teosinte ancestor 3 Genetic evidence can also be used to determine when various lineages split 11 Most historians believe maize was domesticated in the Tehuacan Valley of Mexico 12 Recent research in the early 21st century has modified this view somewhat scholars now indicate the adjacent Balsas River Valley of south central Mexico as the center of domestication 13 An 2002 study by Matsuoka et al has demonstrated that rather than the multiple independent domestications model all maize arose from a single domestication in southern Mexico about 9 000 years ago The study also demonstrated that the oldest surviving maize types are those of the Mexican highlands Later maize spread from this region over the Americas along two major paths This is consistent with a model based on the archaeological record suggesting that maize diversified in the highlands of Mexico before spreading to the lowlands 14 15 Archaeologist Dolores Piperno has said 13 A large corpus of data indicates that maize was dispersed into lower Central America by 7600 BP 5600 BC and had moved into the inter Andean valleys of Colombia between 7000 and 6000 BP 5000 4000 BC Dolores Piperno The Origins of Plant Cultivation and Domestication in the New World Tropics Patterns Process and New Developments 13 Since then even earlier dates have been published 16 According to a genetic study by the Brazilian Agricultural Research Corporation Embrapa corn cultivation was introduced in South America from Mexico in two great waves the first more than 6000 years ago spread through the Andes Evidence of cultivation in Peru has been found dating to about 6700 years ago 17 The second wave about 2000 years ago through the lowlands of South America 18 The earliest maize plants grew only small 25 millimetre long 1 in corn ears and only one per plant In Jackson Spielvogel s view many centuries of artificial selection rather than the current view that maize was exploited by interplanting with teosinte by the indigenous people of the Americas resulted in the development of maize plants capable of growing several ears per plant which were usually several centimetres inches long each 19 The Olmec and Maya cultivated maize in numerous varieties throughout Mesoamerica they cooked ground and processed it through nixtamalization It was believed that beginning about 2500 BC the crop spread through much of the Americas 20 Research of the 21st century has established even earlier dates The region developed a trade network based on surplus and varieties of maize crops citation needed Mapuches of south central Chile cultivated maize along with quinoa and potatoes in pre Hispanic times however potato was the staple food of most Mapuches specially in the southern and coastal Mapuche territories where maize did not reach maturity 21 22 Before the expansion of the Inca Empire maize was traded and transported as far south as 40 19 S in Melinquina Lacar Department 23 In that location maize remains were found inside pottery dated to 730 80 BP and 920 60 BP Probably this maize was brought across the Andes from Chile 23 The presence of maize in Guaitecas Archipelago 43 55 S the southernmost outpost of pre Hispanic agriculture 24 is reported by early Spanish explorers 25 However the Spanish may have misidentified the plant 25 By at least 1000 BCE the Olmec in Mesoamerica had based their calendar language myths and worldview with maize at the center of their symbolism 26 Columbian exchange After the arrival of Europeans in 1492 Spanish settlers consumed maize and explorers and traders carried it back to Europe and introduced it to other countries Spanish settlers much preferred wheat bread to maize cassava or potatoes Maize flour could not be substituted for wheat for communion bread since in Christian belief only wheat could undergo transubstantiation and be transformed into the body of Christ 27 Some Spaniards worried that by eating indigenous foods which they did not consider nutritious they would weaken and risk turning into Indians In the view of Europeans it was the food they ate even more than the environment in which they lived that gave Amerindians and Spaniards both their distinctive physical characteristics and their characteristic personalities 28 Despite these worries Spaniards did consume maize Archeological evidence from Florida sites indicate they cultivated it as well 29 Maize spread to the rest of the world because of its ability to grow in diverse climates It was cultivated in Spain just a few decades after Columbus s voyages and then spread to Italy West Africa and elsewhere 29 Widespread cultivation most likely began in southern Spain in 1525 after which it quickly spread to the rest of the Spanish Empire including its territories in Italy and from there to other Italian states Maize had many advantages over wheat and barley it yielded two and a half times the food energy per unit cultivated area 30 could be harvested in successive years from the same plot of land and grew in wildly varying altitudes and climates from relatively dry regions with only 250 mm 10 in of annual rainfall to damp regions with over 5 000 mm 200 in By the 17th century it was a common peasant food in Southwestern Europe including Portugal Spain southern France and Italy By the 18th century it was the chief food of the southern French and Italian peasantry especially in the form of polenta in Italy 31 Names Many small male flowers make up the male inflorescence called the tassel The word maize derives from the Spanish form of the indigenous Taino word for the plant mahiz 32 Using the maize common name Linnaeus included it as the species epithet in Zea mays 33 It is known by other names including corn in some English speaking countries 34 Maize is preferred in formal scientific and international usage as a common name because it refers specifically to this one grain unlike corn which has a complex variety of meanings that vary by context and geographic region 35 International groups such as the Centre for Agriculture and Bioscience International also consider maize the preferred common name 36 According to Ohio State University the US and a handful of other English speaking countries primarily use corn but the rest of the world calls this maize or maiz 37 The word maize is considered interchangeable with corn in the West during early British and American trade all grains were considered corn Maize retained the name corn in the West as the primary grain in these trade relationships 33 The word corn outside the US Canada Australia and New Zealand is synonymous with grain referring to any cereal crop with its meaning understood to vary geographically to refer to the local staple 38 35 In the United States 38 Canada 39 Australia and New Zealand 40 corn primarily means maize this usage started as a shortening of Indian corn 38 Indian corn primarily means maize the staple grain of indigenous Americans but can refer more specifically to multicolored flint corn used for decoration 41 Other common names include barajovar makka silk maize and zea 42 In a 1999 journal article Betty Fussell describing calling maize as corn was to plunge into tragi farcial mistranslations of language and history Similar to the British the Spanish referred to maize as panizo a generic term for cereal grains as did Italians with the term polenta The British later referred to maize as Turkey wheat Turkey corn or Indian corn with Fusell commenting that they meant not a place but a condition a savage rather than a civilized grain especially with Turkish people later naming it kukuruz or barbaric 43 The word maize is used by agricultural bodies and research institutes such as the UN s FAO 44 the International Maize and Wheat Improvement Center based out of Mexico and the Indian Institute of Maize Research 45 National agricultural and industry associations often include the word maize in their name such as the Maize Association of Australia 46 and the National Maize Association of Nigeria 47 In Southern Africa maize is commonly called mielie Afrikaans or mealie English words possibly derived from the Portuguese word for maize milho but more probably from Dutch meel or English meal meaning the edible part of a grain or pulse 48 Structure and physiologyThe maize plant is often 3 m 10 ft in height 49 though some natural strains can grow 13 m 43 ft 50 and the tallest recorded plant reached almost 14 metres 46 ft 51 The stem is commonly composed of 20 internodes 52 of 18 cm 7 in length 49 The leaves arise from the nodes alternately on opposite sides on the stalk 53 and have entire margins 54 The apex of the stem ends in the tassel an inflorescence of male flowers When the tassel is mature and conditions are suitably warm and dry anthers on the tassel dehisce and release pollen Maize pollen is anemophilous dispersed by wind and because of its large settling velocity most pollen falls within a few meters of the tassel 55 Ears develop above a few of the leaves in the midsection of the plant between the stem and leaf sheath elongating by around 3 mm 1 8 in per day to a length of 18 cm 7 in 49 with 60 cm 24 in being the maximum alleged in the subspecies 56 They are female inflorescences tightly enveloped by several layers of ear leaves commonly called husks Elongated stigmas called silks emerge from the whorl of husk leaves at the end of the ear They are often pale yellow and 18 cm 7 in in length like tufts of hair in appearance At the end of each is a carpel which may develop into a kernel if fertilized by a pollen grain The pericarp of the fruit is fused with the seed coat referred to as caryopsis typical of the grasses and the entire kernel is often referred to as the seed The cob is close to a multiple fruit in structure except that the individual fruits the kernels never fuse into a single mass The grains are about the size of peas and adhere in regular rows around a white pithy substance which forms the cob The maximum size of kernels is reputedly 2 5 cm 1 in 57 An ear commonly holds 600 kernels They are of various colors blackish bluish gray purple green red white and yellow When ground into flour maize yields more flour with much less bran than wheat does It lacks the protein gluten of wheat and therefore makes baked goods with poor rising capability A genetic variant that accumulates more sugar and less starch in the ear is consumed as a vegetable and is called sweet corn Young ears can be consumed raw with the cob and silk but as the plant matures usually during the summer months the cob becomes tougher and the silk dries to inedibility By the end of the growing season the kernels dry out and become difficult to chew without cooking 58 Female inflorescence with young silk Mature silk Stalks ears and silk Male flowers Full grown maize plants Mature maize ear on a stalkPlanting density affects multiple aspects of maize Modern farming techniques in developed countries usually rely on dense planting which produces one ear per stalk 59 Stands of silage maize are yet denser citation needed and achieve a lower percentage of ears and more plant matter citation needed Maize is a facultative short day plant 60 and flowers in a certain number of growing degree days gt 10 C 50 F in the environment to which it is adapted 61 The magnitude of the influence that long nights have on the number of days that must pass before maize flowers is genetically prescribed 62 and regulated by the phytochrome system 63 Photoperiodicity can be eccentric in tropical cultivars such that the long days characteristic of higher latitudes allow the plants to grow so tall that they do not have enough time to produce seed before being killed by frost These attributes however may prove useful in using tropical maize for biofuels 64 Immature maize shoots accumulate a powerful antibiotic substance 2 4 dihydroxy 7 methoxy 1 4 benzoxazin 3 one DIMBOA DIMBOA is a member of a group of hydroxamic acids also known as benzoxazinoids that serve as a natural defense against a wide range of pests including insects pathogenic fungi and bacteria DIMBOA is also found in related grasses particularly wheat A maize mutant bx lacking DIMBOA is highly susceptible to attack by aphids and fungi DIMBOA is also responsible for the relative resistance of immature maize to the European corn borer family Crambidae As maize matures DIMBOA levels and resistance to the corn borer decline citation needed Because of its shallow roots maize is susceptible to droughts intolerant of nutrient deficient soils and prone to be uprooted by severe winds 65 Maize kernels Maize plant diagram Ear of maize with irregular rows of kernels cv Ottofile giallo Tortonese MHNT cv strawberry MHNT cv Oaxacan Green MHNT Variegated maize ears Multicolored corn kernels CSIRO While yellow maizes derive their color from lutein and zeaxanthin in red colored maizes the kernel coloration is due to anthocyanins and phlobaphenes These latter substances are synthesized in the flavonoids synthetic pathway 66 from polymerization of flavan 4 ols 67 by the expression of maize pericarp color1 p1 gene 68 which encodes an R2R3 myb like transcriptional activator 69 of the A1 gene encoding for the dihydroflavonol 4 reductase reducing dihydroflavonols into flavan 4 ols 70 while another gene Suppressor of Pericarp Pigmentation 1 or SPP1 acts as a suppressor 71 The p1 gene encodes an Myb homologous transcriptional activator of genes required for biosynthesis of red phlobaphene pigments while the P1 wr allele specifies colorless kernel pericarp and red cobs and unstable factor for orange1 Ufo1 modifies P1 wr expression to confer pigmentation in kernel pericarp as well as vegetative tissues which normally do not accumulate significant amounts of phlobaphene pigments 68 The maize P gene encodes a Myb homolog that recognizes the sequence CCT AACC in sharp contrast with the C TAACGG bound by vertebrate Myb proteins 72 The ear leaf is the leaf most closely associated with a particular developing ear This leaf and above contribute 70 73 to 75 to 90 74 of grain fill Therefore fungicide application is most important in that region in most disease environments 73 74 Abnormal flowers Maize flowers may sometimes exhibit mutations that lead to the formation of female flowers in the tassel These mutations ts4 and Ts6 prohibit the development of the stamen while simultaneously promoting pistil development 75 This may cause inflorescences containing both male and female flowers or hermaphrodite flowers 76 Genomics and genetics Exotic varieties are collected to add genetic diversity when selectively breeding new domestic strains With white and yellow kernels Maize is an annual grass in the family Gramineae which includes such plants as wheat rye barley rice sorghum and sugarcane There are two major species of the genus Zea out of six total Z mays maize and Z diploperennis which is a perennial type of teosinte The annual teosinte variety called Z m mexicana is the closest botanical relative to maize It still grows in the wild as an annual in Mexico and Guatemala 77 Many forms of maize are used for food sometimes classified as various subspecies related to the amount of starch each has Flour corn Z m var amylacea Popcorn Z m var everta Dent corn Z m var indentata Flint corn Z m var indurata Sweet corn Z m var saccharata and Z m var rugosa Waxy corn Z m var ceratina Amylomaize Z mays verification needed Pod corn Z m var tunicata Larranaga ex A St Hil Striped maize Z m var japonicaThis system has been replaced though not entirely displaced over the last 60 years by multivariable classifications based on ever more data Agronomic data were supplemented by botanical traits for a robust initial classification then genetic cytological protein and DNA evidence was added Now the categories are forms little used races racial complexes and recently branches citation needed Maize is a diploid with 20 chromosomes n 10 The combined length of the chromosomes is 1500 cM Some of the maize chromosomes have what are known as chromosomal knobs highly repetitive heterochromatic domains that stain darkly Individual knobs are polymorphic among strains of both maize and teosinte citation needed Hufford et al 2012 finds that 83 of allelic variation within the genome derives from its teosinte ancestors primarily due to the freedom of Zeas to outcross 78 Barbara McClintock used these knob markers to validate her transposon theory of jumping genes for which she won the 1983 Nobel Prize in Physiology or Medicine Maize is still an important model organism for genetics and developmental biology today 79 The centromeres have two types of structural components both of which are found only in the centromeres Large arrays of CentC a short satellite DNA and a few of a family of retrotransposons The B chromosome unlike the others contains an additional repeat which extends into neighboring areas of the chromosome Centromeres can accidentally shrink during division and still function although it is thought this will fail if it shrinks below a few hundred kilobase Kinetochores contain RNA originating from centromeres Centromere regions can become inactive and can continue in that state if the chromosome still has another active one 80 The Maize Genetics Cooperation Stock Center funded by the USDA Agricultural Research Service and located in the Department of Crop Sciences at the University of Illinois at Urbana Champaign is a stock center of maize mutants The total collection has nearly 80 000 samples The bulk of the collection consists of several hundred named genes plus additional gene combinations and other heritable variants There are about 1000 chromosomal aberrations e g translocations and inversions and stocks with abnormal chromosome numbers e g tetraploids Genetic data describing the maize mutant stocks as well as myriad other data about maize genetics can be accessed at MaizeGDB the Maize Genetics and Genomics Database 81 In 2005 the US National Science Foundation NSF Department of Agriculture USDA and the Department of Energy DOE formed a consortium to sequence the B73 maize genome The resulting DNA sequence data was deposited immediately into GenBank a public repository for genome sequence data Sequences and genome annotations have also been made available throughout the project s lifetime at the project s official site 82 Primary sequencing of the maize genome was completed in 2008 83 On November 20 2009 the consortium published results of its sequencing effort in Science 84 The genome 85 of which is composed of transposons was found to contain 32 540 genes By comparison the human genome contains about 2 9 billion bases and 26 000 genes Much of the maize genome has been duplicated and reshuffled by helitrons group of rolling circle transposons 85 In Z mays and various other angiosperms the MADS box motif is involved in floral development Early study in several angiosperm models including Z mays was the beginning of research into the molecular evolution of floral structure in general as well as their role in nonflowering plants 86 Varieties differ in their resistance to insects including borers 87 CIMMYT maintains a large collection of maize corn accessions tested and cataloged for insect resistance 87 EvolutionAs with many plants and animals Z mays has a positive correlation between effective population size and the magnitude of selection pressure Z m having an EPS of 650 000 it clusters with others of about the same EPS and has 79 of its amino acid sites under selection 88 Recombination is a significant source of diversity in Z mays Note that this finding supersedes previous studies which showed no such correlation 88 This recombination diversity effect is seen throughout plants but is also found to not occur or not as strongly in regions of high gene density This is likely the reason that domesticated Z mays has not seen as much of an increase in diversity within areas of higher density as in regions of lower density although there is more evidence in other plants 88 Some lines of maize have undergone ancient polyploidy events starting 11 million years ago Over that time 72 of polyploid duplicated genes have been retained which is higher than other plants with older polyploidy events Thus maize may be due to lose more duplicate genes as time goes along similar to the course followed by the genomes of other plants If so if gene loss has merely not occurred yet that could explain the lack of observed positive selection and lower negative selection which are observed in otherwise similar plants i e also naturally outcrossing and with similar effective population sizes 88 Ploidy does not appear to influence EPS or magnitude of selection effect in maize 88 BreedingMaize reproduces sexually each year This randomly selects half the genes from a given plant to propagate to the next generation meaning that desirable traits found in the crop like high yield or good nutrition can be lost in subsequent generations unless certain techniques are used citation needed Maize breeding in prehistory resulted in large plants producing large ears Modern breeding began with individuals who selected highly productive varieties in their fields and then sold seed to other farmers James L Reid was one of the earliest and most successful developing Reid s Yellow Dent in the 1860s These early efforts were based on mass selection Later breeding efforts included ear to row selection C G Hopkins c 1896 hybrids made from selected inbred lines G H Shull 1909 and the highly successful double cross hybrids using four inbred lines D F Jones c 1918 1922 University supported breeding programs were especially important in developing and introducing modern hybrids 89 By the 1930s companies such as Pioneer devoted to production of hybrid maize had begun to influence long term development Internationally important seed banks such as the International Maize and Wheat Improvement Center CIMMYT and the US bank at the Maize Genetics Cooperation Stock Center University of Illinois at Urbana Champaign maintain germplasm important for future crop development citation needed Since the 1940s the best strains of maize have been first generation hybrids made from inbred strains that have been optimized for specific traits such as yield nutrition drought pest and disease tolerance Both conventional cross breeding and genetic engineering have succeeded in increasing output and reducing the need for cropland pesticides water and fertilizer 90 There is conflicting evidence to support the hypothesis that maize yield potential has increased over the past few decades This suggests that changes in yield potential are associated with leaf angle lodging resistance tolerance of high plant density disease pest tolerance and other agronomic traits rather than increase of yield potential per individual plant 91 Certain varieties of maize have been bred to produce many ears which are the source of the baby corn used as a vegetable in Asian cuisine 92 CIMMYT operates a conventional breeding program to provide optimized strains The program began in the 1980s Hybrid seeds are distributed in Africa by the Drought Tolerant Maize for Africa project 90 Genetic engineering Main article Transgenic maize Genetically engineered GE maize was one of the 26 GE crops grown commercially in 2016 93 94 The vast majority of this is Bt maize Grown since 1997 in the United States and Canada 95 92 of the US maize crop was genetically modified in 2016 93 96 and 33 of the worldwide maize crop was GM in 2016 93 97 As of 2011 Herbicide tolerant maize varieties were grown in Argentina Australia Brazil Canada China Colombia El Salvador the European Union Honduras Japan Korea Malaysia Mexico New Zealand Philippines the Russian Federation Singapore South Africa Taiwan Thailand and the United States Insect resistant maize was grown in Argentina Australia Brazil Canada Chile China Colombia Egypt the European Union Honduras Japan Korea Malaysia Mexico New Zealand Philippines South Africa Switzerland Taiwan the United States and Uruguay 98 In September 2000 up to 50 million worth of food products were recalled due to the presence of Starlink genetically modified corn which had been approved only for animal consumption and had not been approved for human consumption and was subsequently withdrawn from the market 99 For pest and disease resistance Tropical landraces remain an important and underused source of resistance alleles for disease and for herbivores Notable discoveries of rare alleles for this purpose were made by Dao et al 2014 and Sood et al 2014 100 Rashid et al 2018 use an association mapping panel from CIMMYT originally developed for tropical drought tolerance traits to find new genomic regions providing sorghum downy mildew resistance and to further characterize SDMR regions already located by others 101 OriginSee also Origin of maize and interaction with teosintes Maize is the domesticated variant of teosinte 102 The two plants have dissimilar appearance maize having a single tall stalk with multiple leaves and teosinte being a short bushy plant The difference between the two is largely controlled by differences in just two genes called grassy tillers 1 gt1 A0A317YEZ1 and teosinte branched 1 tb1 Q93WI2 102 Several theories had been proposed about the specific origin of maize in Mesoamerica 103 104 It is a direct domestication of a Mexican annual teosinte Z m ssp parviglumis native to the Balsas River valley in south eastern Mexico 105 with up to 12 of its genetic material obtained from Z m ssp mexicana through introgression 14 It has been derived from hybridization between a small domesticated maize a slightly changed form of a wild maize and a teosinte of section Luxuriantes either Z luxurians or Z diploperennis It has undergone two or more domestications either of a wild maize or of a teosinte The term teosinte describes all species and subspecies in the genus Zea excluding Z m ssp mays It has evolved from a hybridization of Z diploperennis by Tripsacum dactyloides In the late 1930s Paul Mangelsdorf suggested that domesticated maize was the result of a hybridization event between an unknown wild maize and a species of Tripsacum a related genus This theory about the origin of maize has been refuted by modern genetic testing which refutes Mangelsdorf s model and the fourth listed above 103 40 The teosinte origin theory was proposed by the Russian botanist Nikolai Ivanovich Vavilov in 1931 and the later American Nobel Prize winner George Beadle in 1932 103 10 It is supported experimentally and by recent studies of the plants genomes Teosinte and maize can cross breed and produce fertile offspring A number of questions remain concerning the species among them how the immense diversity of the species of sect Zea originated how the tiny archaeological specimens of 3500 2700 BC could have been selected from a teosinte and how domestication could have proceeded without leaving remains of teosinte or maize with teosintoid traits earlier than the earliest known until recently dating from ca 1100 BC The domestication of maize is of particular interest to researchers archaeologists geneticists ethnobotanists geographers etc The process is thought by some to have started 7 500 to 12 000 years ago Research from the 1950s to 1970s originally focused on the hypothesis that maize domestication occurred in the highlands between the states of Oaxaca and Jalisco because the oldest archaeological remains of maize known at the time were found there Connection with parviglumis subspecies Teosinte top maize teosinte hybrid middle maize bottom Ceramic statue of a Maya maize god emerging from an ear of corn 600 900 A D Genetic studies published in 2004 by John Doebley identified Zea mays ssp parviglumis native to the Balsas River valley in Mexico s southwestern highlands and also known as Balsas teosinte as being the crop wild relative that is genetically most similar to modern maize 106 105 This was confirmed by further studies which refined this hypothesis somewhat Archaeobotanical studies published in 2009 point to the middle part of the Balsas River valley as the likely location of early domestication this river is not very long so these locations are not very distant Stone milling tools with maize residue have been found in an 8 700 year old layer of deposits in a cave not far from Iguala Guerrero 107 108 109 Stucco head of the Maya maize god 550 850 AD Doebley was part of the team that first published in 2002 that maize had been domesticated only once about 9 000 years ago and then spread throughout the Americas 14 110 A primitive corn was being grown in southern Mexico Central America and northern South America 7 000 years ago Archaeological remains of early maize ears found at Guila Naquitz Cave in the Oaxaca Valley date back roughly 6 250 years the oldest ears from caves near Tehuacan Puebla 5 450 B P 20 Maize pollen dated to 7 300 B P from San Andres Tabasco on the Caribbean coast has also been recovered 108 As maize was introduced to new cultures new uses were developed and new varieties selected to better serve in those preparations Maize was the staple food or a major staple along with squash Andean region potato quinoa beans and amaranth of most pre Columbian North American Mesoamerican South American and Caribbean cultures The Mesoamerican civilization in particular was deeply interrelated with maize Its traditions and rituals involved all aspects of maize cultivation from the planting to the food preparation Maize formed the Mesoamerican people s identity citation needed It is unknown what precipitated its domestication because the edible portion of the wild variety is too small and hard to obtain to be eaten directly as each kernel is enclosed in a very hard bivalve shell citation needed In 1939 George Beadle demonstrated that the kernels of teosinte are readily popped for human consumption like modern popcorn 111 Some have argued it would have taken too many generations of selective breeding to produce large compressed ears for efficient cultivation However studies of the hybrids readily made by intercrossing teosinte and modern maize suggest this objection is not well founded citation needed Spreading to the north Around 4 500 ago maize began to spread to the north it was first cultivated in what is now the United States at several sites in New Mexico and Arizona about 4 100 ago 112 During the first millennium AD maize cultivation spread more widely in the areas north In particular the large scale adoption of maize agriculture and consumption in eastern North America took place about A D 900 Native Americans cleared large forest and grassland areas for the new crop 113 In 2005 research by the USDA Forest Service suggested that the rise in maize cultivation 500 to 1 000 years ago in what is now the southeastern United States corresponded with a decline of freshwater mussels which are very sensitive to environmental changes 114 CultivationPlanting Seedlings three weeks after sowing Young stalks Because it is cold intolerant in the temperate zones maize must be planted in the spring Its root system is generally shallow so the plant is dependent on soil moisture As a plant that uses C4 carbon fixation maize is a considerably more water efficient crop than plants that use C3 carbon fixation such as alfalfa and soybeans Maize is most sensitive to drought at the time of silk emergence when the flowers are ready for pollination In the United States a good harvest was traditionally predicted if the maize was knee high by the Fourth of July although modern hybrids generally exceed this growth rate Maize used for silage is harvested while the plant is green and the fruit immature Sweet corn is harvested in the milk stage after pollination but before starch has formed between late summer and early to mid autumn Field maize is left in the field until very late in the autumn to thoroughly dry the grain and may in fact sometimes not be harvested until winter or even early spring The importance of sufficient soil moisture is shown in many parts of Africa where periodic drought regularly causes maize crop failure and consequent famine Although it is grown mainly in wet hot climates it has been said to thrive in cold hot dry or wet conditions meaning that it is an extremely versatile crop 115 Mature plants showing ears Maize was planted by the Native Americans in hills in a complex system known to some as the Three Sisters 116 Maize provided support for beans and the beans provided nitrogen derived from nitrogen fixing rhizobia bacteria which live on the roots of beans and other legumes and squashes provided ground cover to stop weeds and inhibit evaporation by providing shade over the soil 117 This method was replaced by single species hill planting where each hill 60 120 cm 2 ft 0 in 3 ft 11 in apart was planted with three or four seeds a method still used by home gardeners A later technique was checked maize where hills were placed 1 m 40 in apart in each direction allowing cultivators to run through the field in two directions In more arid lands this was altered and seeds were planted in the bottom of 10 12 cm 4 4 1 2 in deep furrows to collect water Modern technique plants maize in rows which allows for cultivation while the plant is young although the hill technique is still used in the maize fields of some Native American reservations When maize is planted in rows it also allows for planting of other crops between these rows to make more efficient use of land space 118 In most regions today maize grown in residential gardens is still often planted manually with a hoe whereas maize grown commercially is no longer planted manually but rather is planted with a planter In North America fields are often planted in a two crop rotation with a nitrogen fixing crop often alfalfa in cooler climates and soybeans in regions with longer summers Sometimes a third crop winter wheat is added to the rotation citation needed Many of the maize varieties grown in the United States and Canada are hybrids Often the varieties have been genetically modified to tolerate glyphosate or to provide protection against natural pests Glyphosate is an herbicide which kills all plants except those with genetic tolerance This genetic tolerance is very rarely found in nature citation needed In the midwestern United States low till or no till farming techniques are usually used In low till fields are covered once maybe twice with a tillage implement either ahead of crop planting or after the previous harvest The fields are planted and fertilized Weeds are controlled through the use of herbicides and no cultivation tillage is done during the growing season This technique reduces moisture evaporation from the soil and thus provides more moisture for the crop The technologies mentioned in the previous paragraph enable low till and no till farming Weeds compete with the crop for moisture and nutrients making them undesirable citation needed Harvesting Mature maize ears Harvesting maize Jones County Iowa Harvesting maize Rantasalmi South Savonia Finland Hand picking harvest of maize in Myanmar Maize harvested as a grain crop can be kept in the field a relatively long time even months after the crop is ready to harvest it is also harvested and stored in the husk leaves if kept dry 119 Before the 20th century all maize harvesting was by manual labour by grazing or by some combination of those Whether the ears were hand picked and the stover was grazed or the whole plant was cut gathered and shocked people and livestock did all the work Between the 1890s and the 1970s the technology of maize harvesting expanded greatly Today all such technologies from entirely manual harvesting to entirely mechanized are still in use to some degree as appropriate to each farm s needs although the thoroughly mechanized versions predominate as they offer the lowest unit costs when scaled to large farm operations Before World War II most maize in North America was harvested by hand This involved a large number of workers and associated social events husking or shucking bees From the 1890s onward some machinery became available to partially mechanize the processes such as one and two row mechanical pickers picking the ear leaving the stover and corn binders which are reaper binders designed specifically for maize for example Video on YouTube The latter produce sheaves that can be shocked By hand or mechanical picker the entire ear is harvested which then requires a separate operation of a maize sheller to remove the kernels from the ear Whole ears of maize were often stored in corn cribs and these whole ears are a sufficient form for some livestock feeding use Today corn cribs with whole ears and corn binders are less common because most modern farms harvest the grain from the field with a combine and store it in bins The combine with a corn head with points and snap rolls instead of a reel does not cut the stalk it simply pulls the stalk down The stalk continues downward and is crumpled into a mangled pile on the ground where it usually is left to become organic matter for the soil The ear of maize is too large to pass between slots in a plate as the snap rolls pull the stalk away leaving only the ear and husk to enter the machinery The combine separates the husk and the cob keeping only the kernels 120 The entire maize plant is also harvested as a silage crop 121 For storing grain in bins the moisture of the grain must be sufficiently low to avoid spoiling If the moisture content of the harvested grain is too high grain dryers are used to reduce the moisture content by blowing heated air through the grain This can require large amounts of energy in the form of combustible gases propane or natural gas and electricity to power the blowers 122 Production Production of maize 2019 123 Maize is widely cultivated throughout the world and a greater weight of maize is produced each year than any other grain 8 In 2020 total world production was 1 16 billion tonnes led by the United States with 31 0 of the total table China produced 22 4 of the global total 124 Maize production 2020 125 124 Country Production millions of tonnes United States 360 3 China 260 7 Brazil 104 0 Argentina 58 4 Ukraine 30 3 India 30 2 Mexico 27 4 Indonesia 22 5 South Africa 15 3 Russia 13 9 World 1162 4United States Main article Corn production in the United States In 2016 maize production was forecast to be over 380 million metric tons 15 billion bushels an increase of 11 over 2014 American production 126 Based on conditions as of August 2016 the expected yield would be the highest ever for the United States 126 The area of harvested maize was forecast to be 35 million hectares 87 million acres an increase of 7 over 2015 126 Maize is especially popular in Midwestern states such as Indiana Iowa and Illinois in the latter it was named the state s official grain in 2017 127 The estimated corn usage for crop year September 1 2020 to August 31 2021 was 38 7 percent was used for feed 34 percent for ethanol 17 5 percent for export and 9 8 percent for food 128 Trade Corn futures are traded on several exchanges the Chicago Board of Trade CBOT and JSE Derivatives JDERIV The Chicago Board Of Trade sells corn futures with a contact size of 5000 bushels which is quoted in cents bushel and the JDERIV has a contact size of 100 Tonnes quoted in Rand Ton 129 130 The detailed contract specifications are listed below Contract Specifications 129 130 Corn CORN Corn CNA Exchange JDERIV CBOTSector Grain GrainTick Size 0 2 0 25Tick Value 5 ZAR 12 50 USDBPV 25 50Denomination ZAR USDDecimal Place 1 2PestsInsects African armyworm Spodoptera exempta African sugarcane borer Eldana saccharina Asian corn borer Ostrinia furnacalis Common armyworm Pseudaletia unipuncta Common earwig Forficula auricularia Corn delphacid Peregrinus maidis Corn leaf aphid Rhopalosiphum maidis Corn rootworms Diabrotica spp including Western corn rootworm Diabrotica virgifera virgifera LeConte Northern corn rootworm D barberi or D longicornis and Southern corn rootworm D undecimpunctata howardi Corn silkfly Euxesta stigmatias Dusky sap beetle Carpophilus lugubris European corn borer Ostrinia nubilalis ECB Fall armyworm Spodoptera frugiperda Some sweet corn varieties have developed partial resistance to fall army worms by producing a unique 33 kD proteinase that significantly retards fall army worm growth 131 132 Corn earworm Cotton bollworm Helicoverpa zea Lesser cornstalk borer Elasmopalpus lignosellus Maize weevil Sitophilus zeamais Northern armyworm Oriental armyworm or Rice ear cutting caterpillar Mythimna separata Southwestern corn borer Diatraea grandiosella Stalk borer Papaipema nebris The susceptibility of maize to the European corn borer and corn rootworms and the resulting large crop losses which are estimated at a billion dollars worldwide for each pest 133 134 135 led to the development of transgenics expressing the Bacillus thuringiensis toxin Bt maize is widely grown in the United States and has been approved for release in Europe Diseases Main article List of maize diseases Rust Corn smut or common smut Ustilago maydis a fungal disease known in Mexico as huitlacoche which is prized by some as a gourmet delicacy in itself Northern corn leaf blight Purdue Extension site Pioneer site Archived June 24 2017 at the Wayback Machine Southern corn leaf blight Maize downy mildew Peronosclerospora spp Maize dwarf mosaic virus Maize streak virus Stewart s wilt Pantoea stewartii Goss s wilt Clavibacter michiganensis subsp nebraskensis 136 Grey leaf spot 137 Mal de Rio Cuarto virus MRCV Stalk rot Ear rot Aspergillus flavus 95 A parasiticus 95 Storage Drying is vital to prevent or at least reduce mycotoxin contamination Aspergillus and Fusarium spp are the most common mycotoxin sources but there are others Altogether maize contaminants are so common and this crop is so economically important that maize mycotoxins are among the most important in agriculture in general 95 UsesHuman food Further information List of corn dishes Semi peeled corn on the cob Poster showing a woman serving muffins pancakes and grits with canisters on the table labeled corn meal grits and hominy US Food Administration 1918 Maize and cornmeal ground dried maize constitute a staple food in many regions of the world Maize is used to produce cornstarch a common ingredient in home cooking and many industrialized food products Maize starch can be hydrolyzed and enzymatically treated to produce syrups particularly high fructose corn syrup a sweetener and also fermented and distilled to produce grain alcohol Grain alcohol from maize is traditionally the source of Bourbon whiskey Corn flour is used to make cornbread and other baked products citation needed In prehistoric times Mesoamerican women used a metate to process maize into ground cornmeal allowing the preparation of foods that were more calorie dense than popcorn After ceramic vessels were invented the Olmec people began to cook maize together with beans improving the nutritional value of the staple meal Although maize naturally contains niacin an important nutrient it was not bioavailable without the process of nixtamalization The Maya used nixtamal meal to make varieties of porridges and tamales 138 The process was later used in the cuisine of the American South to prepare corn for grits and hominy citation needed Maize is a staple of Mexican cuisine Masa cornmeal treated with limewater is the main ingredient for tortillas atole and many other dishes of Central American food It is the main ingredient of corn tortilla tamales pozole atole and all the dishes based on them like tacos quesadillas chilaquiles enchiladas tostadas and many more In Mexico the fungus of maize known as huitlacoche is considered a delicacy citation needed Mexican tamales made with corn meal Boiled corn on a white plate Coarse maize meal is made into a thick porridge in many cultures from the polenta of Italy the angu of Brazil the mămăligă of Romania to cornmeal mush in the US or hominy grits in the South or the food called mieliepap in South Africa and sadza nshima ugali and other names in other parts of Africa Introduced into Africa by the Portuguese in the 16th century maize has become Africa s most important staple food crop 139 These are commonly eaten in the Southeastern United States foods handed down from Native Americans who called the dish sagamite citation needed Maize can also be harvested and consumed in the unripe state when the kernels are fully grown but still soft Unripe maize must usually be cooked to become palatable this may be done by simply boiling or roasting the whole ears and eating the kernels right off the cob Sweet corn a genetic variety that is high in sugars and low in starch is usually consumed in the unripe state Such corn on the cob is a common dish in the United States Canada United Kingdom Cyprus some parts of South America and the Balkans but virtually unheard of in some European countries citation needed Corn on the cob was hawked on the streets of early 19th century New York City by poor barefoot Hot Corn Girls who were thus the precursors of hot dog carts churro wagons and fruit stands seen on the streets of big cities today 140 Within the United States the usage of maize for human consumption constitutes only around 1 40th of the amount grown in the country In the United States and Canada maize is mostly grown to feed livestock as forage silage made by fermentation of chopped green cornstalks or grain Maize meal is also a significant ingredient of some commercial animal food products citation needed Nutritional value Sweetcorn yellow raw seeds only Note assuming freed niacinNutritional value per 100 g 3 5 oz Energy360 kJ 86 kcal Carbohydrates18 7 gStarch5 7 gSugars6 26 gDietary fiber2 gFat1 35 gProtein3 27 gTryptophan0 023 gThreonine0 129 gIsoleucine0 129 gLeucine0 348 gLysine0 137 gMethionine0 067 gCystine0 026 gPhenylalanine0 150 gTyrosine0 123 gValine0 185 gArginine0 131 gHistidine0 089 gAlanine0 295 gAspartic acid0 244 gGlutamic acid0 636 gGlycine0 127 gProline0 292 gSerine0 153 gVitaminsQuantity DV Vitamin A equiv lutein zeaxanthin1 9 mg644 mgThiamine B1 13 0 155 mgRiboflavin B2 5 0 055 mgNiacin B3 12 1 77 mgPantothenic acid B5 14 0 717 mgVitamin B67 0 093 mgFolate B9 11 42 mgVitamin C8 6 8 mgMineralsQuantity DV Iron4 0 52 mgMagnesium10 37 mgManganese8 0 163 mgPhosphorus13 89 mgPotassium6 270 mgZinc5 0 46 mgOther constituentsQuantityWater75 96 gLink to USDA Database entryOne ear of medium size 6 3 4 to 7 1 2 long maize has 90 grams of seedsUnits mg micrograms mg milligrams IU International units Percentages are roughly approximated using US recommendations for adults Source USDA FoodData CentralRaw yellow sweet maize kernels are composed of 76 water 19 carbohydrates 3 protein and 1 fat table In a 100 gram serving maize kernels provide 86 calories and are a good source 10 19 of the Daily Value of the B vitamins thiamin niacin but see Pellagra warning below pantothenic acid B5 and folate right table for raw uncooked kernels USDA Nutrient Database In moderate amounts they also supply dietary fiber and the essential minerals magnesium and phosphorus whereas other nutrients are in low amounts table citation needed Maize has suboptimal amounts of the essential amino acids tryptophan and lysine which accounts for its lower status as a protein source 141 However the proteins of beans and legumes complement those of maize 141 Feed and fodder for livestock See also Corn stover Uses Maize is a major source of both grain feed and fodder for livestock It is fed to the livestock in various ways When it is used as a grain crop the dried kernels are used as feed They are often kept on the cob for storage in a corn crib or they may be shelled off for storage in a grain bin The farm that consumes the feed may produce it purchase it on the market or some of both When the grain is used for feed the rest of the plant the corn stover can be used later as fodder bedding litter or soil amendment When the whole maize plant grain plus stalks and leaves is used for fodder it is usually chopped all at once and ensilaged as digestibility and palatability are higher in the ensilaged form than in the dried form Maize silage is one of the most valuable forages for ruminants 142 Before the advent of widespread ensilaging it was traditional to gather the corn into shocks after harvesting where it dried further With or without a subsequent move to the cover of a barn it was then stored for weeks to several months until fed to the livestock Today ensilaging can occur not only in siloes but also in silage wrappers However in the tropics maize can be harvested year round and fed as green forage to the animals 143 Chemicals Starch from maize can also be made into plastics fabrics adhesives and many other chemical products citation needed The corn steep liquor a plentiful watery byproduct of maize wet milling process is widely used in the biochemical industry and research as a culture medium to grow many kinds of microorganisms 144 Chrysanthemin is found in purple corn and is used as a food coloring citation needed Bio fuel See also Corn ethanol and Corn stover Feed maize is being used increasingly for heating 145 specialized corn stoves similar to wood stoves are available and use either feed maize or wood pellets to generate heat Maize cobs are also used as a biomass fuel source Maize is relatively cheap and home heating furnaces have been developed which use maize kernels as a fuel They feature a large hopper that feeds the uniformly sized maize kernels or wood pellets or cherry pits into the fire citation needed Maize is increasingly used as a feedstock for the production of ethanol fuel 146 When considering where to construct an ethanol plant one of the site selection criteria is to ensure there is locally available feedstock 147 Ethanol is mixed with gasoline to decrease the amount of pollutants emitted when used to fuel motor vehicles High fuel prices in mid 2007 led to higher demand for ethanol which in turn led to higher prices paid to farmers for maize This led to the 2007 harvest being one of the most profitable maize crops in modern history for farmers Because of the relationship between fuel and maize prices paid for the crop now tend to track the price of oil citation needed The price of food is affected to a certain degree by the use of maize for biofuel production The cost of transportation production and marketing are a large portion 80 of the price of food in the United States Higher energy costs affect these costs especially transportation The increase in food prices the consumer has been seeing is mainly due to the higher energy cost The effect of biofuel production on other food crop prices is indirect Use of maize for biofuel production increases the demand and therefore price of maize This in turn results in farm acreage being diverted from other food crops to maize production This reduces the supply of the other food crops and increases their prices 148 149 Farm based maize silage digester located near Neumunster in Germany 2007 Green inflatable biogas holder is shown on top of the digester Maize is widely used in Germany as a feedstock for biogas plants Here the maize is harvested shredded then placed in silage clamps from which it is fed into the biogas plants This process makes use of the whole plant rather than simply using the kernels as in the production of fuel ethanol citation needed A biomass gasification power plant in Strem near Gussing Burgenland Austria began in 2005 There is potential that diesel can be created from the biogas by the Fischer Tropsch method 150 Increasingly ethanol is being used at low concentrations 10 or less as an additive in gasoline gasohol for motor fuels to increase the octane rating lower pollutants and reduce petroleum use what is nowadays also known as biofuels and has been generating an intense debate regarding the human beings necessity of new sources of energy on the one hand and the need to maintain in regions such as Latin America the food habits and culture which has been the essence of civilizations such as the one originated in Mesoamerica the entry January 2008 of maize among the commercial agreements of NAFTA has increased this debate considering the bad labor conditions of workers in the fields and mainly the fact that NAFTA opened the doors to the import of maize from the United States where the farmers who grow it receive multimillion dollar subsidies and other government supports According to OXFAM UK after NAFTA went into effect the price of maize in Mexico fell 70 between 1994 and 2001 The number of farm jobs dropped as well from 8 1 million in 1993 to 6 8 million in 2002 Many of those who found themselves without work were small scale maize growers 151 However introduction in the northern latitudes of the US of tropical maize for biofuels and not for human or animal consumption may potentially alleviate this citation needed Commodity Maize is bought and sold by investors and price speculators as a tradable commodity using corn futures contracts These futures are traded on the Chicago Board of Trade CBOT under ticker symbol C They are delivered every year in March May July September and December 152 Ornamental and other uses Main article Corn construction Some forms of the plant are occasionally grown for ornamental use in the garden For this purpose variegated and colored leaf forms as well as those with colorful ears are used citation needed Corncobs can be hollowed out and treated to make inexpensive smoking pipes first manufactured in the United States in 1869 citation needed Children playing in a maize kernel box An unusual use for maize is to create a corn maze or maize maze as a tourist attraction The idea of a maize maze was introduced by the American Maze Company who created a maze in Pennsylvania in 1993 153 better source needed Traditional mazes are most commonly grown using yew hedges but these take several years to mature The rapid growth of a field of maize allows a maze to be laid out using GPS at the start of a growing season and for the maize to grow tall enough to obstruct a visitor s line of sight by the start of the summer In Canada and the US these are popular in many farming communities citation needed Maize kernels can be used in place of sand in a sandboxlike enclosure for children s play 154 Stigmas from female maize flowers popularly called corn silk are sold as herbal supplements citation needed Maize is used as a fish bait called dough balls It is particularly popular in Europe for coarse fishing citation needed Additionally feed corn is sometimes used by hunters to bait animals such as deer or wild hogs citation needed United States usage breakdown The breakdown of usage of the 12 1 billion bushel 307 million tonne 2008 US maize crop was as follows according to the World Agricultural Supply and Demand Estimates Report by the USDA 155 Use Amountmillion bushels million tonnes percentagelivestock feed 5 250 133 4 43 4ethanol production 3 650 92 7 30 2exports 1 850 47 0 15 3production of starch corn oil sweeteners HFCS etc 943 24 0 7 8human consumption grits corn flour corn meal beverage alcohol 327 8 3 2 7In the US since 2009 2010 maize feedstock use for ethanol production has somewhat exceeded direct use for livestock feed maize use for fuel ethanol was 5 130 million bushels 130 million tonnes in the 2013 2014 marketing year 156 A fraction of the maize feedstock dry matter used for ethanol production is usefully recovered as DDGS dried distillers grains with solubles In the 2010 2011 marketing year about 29 1 million tonnes of DDGS were fed to US livestock and poultry 157 Because starch utilization in fermentation for ethanol production leaves other grain constituents more concentrated in the residue the feed value per kg of DDGS with regard to ruminant metabolizable energy and protein exceeds that of the grain Feed value for monogastric animals such as swine and poultry is somewhat lower than for ruminants 157 Comparison to other staple foodsNutrient contents in DV of common foods raw uncooked per 100 g Protein Fiber Vitamins MineralsFood DV Q DV A B1 B2 B3 B5 B6 B9 B12 Ch C D E K Ca Fe Mg P K Na Zn Cu Mn Secooking Reduction 10 30 20 25 25 35 0 0 30 10 15 20 10 20 5 10 25Corn 20 55 6 1 13 4 16 4 19 19 0 0 0 0 0 1 1 11 31 34 15 1 20 10 42 0Rice 14 71 1 3 0 12 3 11 20 5 2 0 0 0 0 0 0 1 9 6 7 2 0 8 9 49 22Wheat 27 51 40 0 28 7 34 19 21 11 0 0 0 0 0 0 3 20 36 51 12 0 28 28 151 128Soybean dry 73 132 31 0 58 51 8 8 19 94 0 24 10 0 4 59 28 87 70 70 51 0 33 83 126 25Pigeon pea dry 42 91 50 1 43 11 15 13 13 114 0 0 0 0 0 0 13 29 46 37 40 1 18 53 90 12Potato 4 112 7 3 0 5 2 5 3 15 4 0 0 33 0 0 2 1 4 6 6 12 0 2 5 8 0Sweet potato 3 82 10 284 5 4 3 8 10 3 0 0 4 0 1 2 3 3 6 5 10 2 2 8 13 1Spinach 6 119 7 3 188 5 11 4 1 10 49 0 4 5 47 0 10 604 10 15 20 5 16 3 4 6 45 1Dill 7 32 7 154 4 17 8 4 9 38 0 0 142 0 0 0 21 37 14 7 21 3 6 7 63 0Carrots 2 9 3 334 4 3 5 3 7 5 0 0 10 0 3 16 3 2 3 4 9 3 2 2 7 0Guava 5 24 18 12 4 2 5 5 6 12 0 0 381 0 4 3 2 1 5 4 12 0 2 11 8 1Papaya 1 7 5 6 22 2 2 2 2 1 10 0 0 103 0 4 3 2 1 2 1 7 0 0 1 1 1Pumpkin 2 56 1 6 184 3 6 3 3 3 4 0 0 15 0 5 1 2 4 3 4 10 0 2 6 6 0Sunflower oil 0 0 0 0 0 0 0 0 0 0 0 0 0 205 7 0 0 0 0 0 0 0 0 0 0Egg 25 136 0 10 5 28 0 14 7 12 22 45 0 9 5 0 5 10 3 19 4 6 7 5 2 45Milk 6 138 0 2 3 11 1 4 2 1 7 2 6 0 0 0 0 11 0 2 9 4 2 3 1 0 5Chicken Liver 34 149 0 222 20 105 49 62 43 147 276 30 0 4 0 1 50 5 30 7 3 18 25 13 78 DV daily value i e of DRI Dietary Reference Intake Note All nutrient values including protein and fiber are in DV per 100 grams of the food item Significant values are highlighted in light Gray color and bold letters 158 159 Cooking reduction Maximum typical reduction in nutrients due to boiling without draining for ovo lacto vegetables group 160 161 Q Quality of Protein in terms of completeness without adjusting for digestability 161 The following table shows the nutrient content of maize and major staple foods in a raw harvested form on a dry weight basis to account for their different water contents Raw forms are not edible and cannot be digested These must be sprouted or prepared and cooked for human consumption In sprouted or cooked form the relative nutritional and anti nutritional contents of each of these staples are different from that of raw form of these staples reported in the table below Note niacin for maize assumes freed niacin Nutrient content of 10 major staple foods per 100 g dry weight 162 Staple Maize corn A Rice white B Wheat C Potatoes D Cassava E Soybeans green F Sweet potatoes G Yams Y Sorghum H Plantain Z RDAWater content 10 12 13 79 60 68 77 70 9 65Raw grams per 100 g dry weight 111 114 115 476 250 313 435 333 110 286NutrientEnergy kJ 1698 1736 1574 1533 1675 1922 1565 1647 1559 1460 8 368 10 460Protein g 10 4 8 1 14 5 9 5 3 5 40 6 7 0 5 0 12 4 3 7 50Fat g 5 3 0 8 1 8 0 4 0 7 21 6 0 2 0 6 3 6 1 1 44 77Carbohydrates g 82 91 82 81 95 34 87 93 82 91 130Fiber g 8 1 1 5 14 0 10 5 4 5 13 1 13 0 13 7 6 9 6 6 30Sugar g 0 7 0 1 0 5 3 7 4 3 0 0 18 2 1 7 0 0 42 9 minimalMinerals A B C D E F G Y H Z RDACalcium mg 8 32 33 57 40 616 130 57 31 9 1 000Iron mg 3 01 0 91 3 67 3 71 0 68 11 09 2 65 1 80 4 84 1 71 8Magnesium mg 141 28 145 110 53 203 109 70 0 106 400Phosphorus mg 233 131 331 271 68 606 204 183 315 97 700Potassium mg 319 131 417 2005 678 1938 1465 2720 385 1426 4700Sodium mg 39 6 2 29 35 47 239 30 7 11 1 500Zinc mg 2 46 1 24 3 05 1 38 0 85 3 09 1 30 0 80 0 00 0 40 11Copper mg 0 34 0 25 0 49 0 52 0 25 0 41 0 65 0 60 0 23 0 9Manganese mg 0 54 1 24 4 59 0 71 0 95 1 72 1 13 1 33 2 3Selenium mg 17 2 17 2 81 3 1 4 1 8 4 7 2 6 2 3 0 0 4 3 55Vitamins A B C D E F G Y H Z RDAVitamin C mg 0 0 0 0 0 0 93 8 51 5 90 6 10 4 57 0 0 0 52 6 90Thiamin B1 mg 0 43 0 08 0 34 0 38 0 23 1 38 0 35 0 37 0 26 0 14 1 2Riboflavin B2 mg 0 22 0 06 0 14 0 14 0 13 0 56 0 26 0 10 0 15 0 14 1 3Niacin B3 mg 4 03 1 82 6 28 5 00 2 13 5 16 2 43 1 83 3 22 1 97 16Pantothenic acid B5 mg 0 47 1 15 1 09 1 43 0 28 0 47 3 48 1 03 0 74 5Vitamin B6 mg 0 69 0 18 0 34 1 43 0 23 0 22 0 91 0 97 0 86 1 3Folate Total B9 mg 21 9 44 76 68 516 48 77 0 63 400Vitamin A IU 238 0 10 10 33 563 4178 460 0 3220 5000Vitamin E alpha tocopherol mg 0 54 0 13 1 16 0 05 0 48 0 00 1 13 1 30 0 00 0 40 15Vitamin K1 mg 0 3 0 1 2 2 9 0 4 8 0 0 7 8 8 7 0 0 2 0 120Beta carotene mg 108 0 6 5 20 0 36996 277 0 1306 10500Lutein zeaxanthin mg 1506 0 253 38 0 0 0 0 0 86 6000Fats A B C D E F G Y H Z RDASaturated fatty acids g 0 74 0 20 0 30 0 14 0 18 2 47 0 09 0 13 0 51 0 40 minimalMonounsaturated fatty acids g 1 39 0 24 0 23 0 00 0 20 4 00 0 00 0 03 1 09 0 09 22 55Polyunsaturated fatty acids g 2 40 0 20 0 72 0 19 0 13 10 00 0 04 0 27 1 51 0 20 13 19 A B C D E F G Y H Z RDAA raw yellow dent cornB raw unenriched long grain white riceC raw hard red winter wheatD raw potato with flesh and skinE raw cassavaF raw green soybeansG raw sweet potatoH raw sorghumY raw yamZ raw plantains unofficialHazardsPellagra Main article Pellagra When maize was first introduced into farming systems other than those used by traditional native American peoples it was generally welcomed with enthusiasm for its productivity However a widespread problem of malnutrition soon arose wherever maize was introduced as a staple food This was a mystery since these types of malnutrition were not normally seen among the indigenous Americans for whom maize was the principal staple food 163 It was eventually discovered that the indigenous Americans had learned to soak maize in alkali water the process now known as nixtamalization made with ashes and lime calcium oxide since at least 1200 1500 BC by Mesoamericans They did this to liberate the corn hulls but unbeknownst to natives or colonists it coincidentally liberates the B vitamin niacin the lack of which was the underlying cause of the condition known as pellagra 164 Maize was introduced into the diet of non indigenous Americans without the necessary cultural knowledge acquired over thousands of years in the Americas In the late 19th century pellagra reached epidemic proportions in parts of the southern US as medical researchers debated two theories for its origin the deficiency theory which was eventually shown to be true said that pellagra was due to a deficiency of some nutrient and the germ theory said that pellagra was caused by a germ transmitted by stable flies A third theory promoted by the eugenicist Charles Davenport held that people only contracted pellagra if they were susceptible to it due to certain constitutional inheritable traits of the affected individual 165 Once alkali processing and dietary variety were understood and applied pellagra disappeared in the developed world The development of high lysine maize and the promotion of a more balanced diet have also contributed to its demise Pellagra still exists today in food poor areas and refugee camps where people survive on donated maize 166 Allergy Main article Corn allergy Maize contains lipid transfer protein an indigestible protein that survives cooking This protein has been linked to a rare and understudied allergy to maize in humans 167 The allergic reaction can cause skin rash swelling or itching of mucous membranes diarrhea vomiting asthma and in severe cases anaphylaxis It is unclear how common this allergy is in the general population citation needed The Z mays plant has an OPALS allergy scale rating of 5 out of 10 indicating moderate potential to cause allergic reactions exacerbated by over use of the same plant throughout a garden Corn pollen is heavy large and usually airborne in the early morning 168 Mycotoxins Fungicide application does not reduce fungal growth or mycotoxin dramatically although it can be a part of a successful reduction strategy Among the most common toxins are those produced by Aspergillus and Fusarium spp The most common toxins are aflatoxins fumonisins zearalenone and ochratoxin A Bt maize discourages insect vectors and by so doing it dramatically reduces concentrations of fumonisins significantly reduces aflatoxins but only mildly reduces others 95 Art Gold maize Moche culture 300 A D Larco Museum Lima Peru Water tower in Rochester Minnesota being painted as an ear of maize Maize has been an essential crop in the Andes since the pre Columbian era The Moche culture from Northern Peru made ceramics from earth water and fire This pottery was a sacred substance formed in significant shapes and used to represent important themes Maize was represented anthropomorphically as well as naturally 169 In the United States maize ears along with tobacco leaves are carved into the capitals of columns in the United States Capitol building Maize itself is sometimes used for temporary architectural detailing when the intent is to celebrate the fall season local agricultural productivity and culture Bundles of dried maize stalks are often displayed along with pumpkins gourds and straw in autumnal displays outside homes and businesses A well known example of architectural use is the Corn Palace in Mitchell South Dakota which uses cobs and ears of colored maize to implement a mural design that is recycled annually Another well known example is the Field of Corn sculpture in Dublin Ohio where hundreds of concrete ears of corn stand in a grassy field 170 A maize stalk with two ripe ears is depicted on the reverse of the Croatian 1 lipa coin minted since 1993 171 See also Food portal Agriculture and Agronomy portalBlue corn Purple corn Columbian Exchange Corn syrup Crop circle Detasseling List of maize dishes List of sweetcorn varieties Post harvest losses grains Push pull technology pest control strategy for maize and sorghum ZeinReferences Contreras A Ruiz Corral J A Menjivar J Aragon Cuevas F Gonzalez Ledesma M amp Sanchez J J 2019 Zea mays The IUCN Red List of Threatened Species 2019 e T77726273A77726310 https dx doi org 10 2305 IUCN UK 2019 2 RLTS T77726273A77726310 en Accessed on 28 October 2022 The Evolution of Corn University of Utah HEALTH SCIENCES Retrieved January 2 2016 a b c Benz B F 2001 Archaeological evidence of teosinte domestication from Guila Naquitz Oaxaca Proceedings of the National Academy of Sciences 98 4 2104 2106 Bibcode 2001PNAS 98 2104B doi 10 1073 pnas 98 4 2104 PMC 29389 PMID 11172083 Please settle a dispute Is sweet corn a vegetable or a grain What is the difference How about field corn eXtension USDA National Institute of Food and Agriculture New Technologies for Ag Extension project Archived from the original on June 21 2018 Retrieved March 3 2018 Chodosh Sara July 8 2021 The bizarre botany that makes corn a fruit a grain and also kind of a vegetable Popular Science Retrieved February 24 2022 Foley Jonathon It s Time to Rethink America s Corn System Scientific American Retrieved February 18 2019 Linda Campbell Franklin Corn in Andrew F Smith ed The Oxford Encyclopedia of Food and Drink in America 2nd ed Oxford Oxford University Press 2013 pp 551 558 p 553 a b International Grains Council international organization 2013 International Grains Council Market Report 28 November 2013 PDF Genetically modified plants Global Cultivation Area Maize Archived August 12 2010 at the Wayback Machine GMO Compass March 29 2010 retrieved August 10 2010 Corn Production By State 2021 worldpopulationreview com Retrieved July 16 2021 Blake Michael August 28 2015 Maize for the Gods Unearthing the 9 000 Year History of Corn Univ of California Press ISBN 978 0 520 27687 1 Origin History and Uses of Corn Iowa State University Department of Agronomy February 11 2014 Archived from the original on February 23 2014 a b c Piperno Dolores R 2011 The Origins of Plant Cultivation and Domestication in the New World Tropics Patterns Process and New Developments Current Anthropology 52 S4 453 S470 doi 10 1086 659998 S2CID 83061925 Recent studies in the Central Balsas River Valley of Mexico maize s postulated cradle of origin document the presence of maize phytoliths and starch grains at 8700 BP the earliest date recorded for the crop Piperno et al 2009 Ranere et al 2009 A large corpus of data indicates that it was dispersed into lower Central America by 7600 BP and had moved into the inter Andean valleys of Colombia between 7000 and 6000 BP Given the number of Cauca Valley Colombia sites that demonstrate early maize it is likely that the inter Andean valleys were a major dispersal route for the crop after it entered South America a b c Matsuoka Y Vigouroux Y Goodman M M et al 2002 A single domestication for maize shown by multilocus microsatellite genotyping Proceedings of the National Academy of Sciences 99 9 6080 4 Bibcode 2002PNAS 99 6080M doi 10 1073 pnas 052125199 PMC 122905 PMID 11983901 Matsuoka Yoshihiro January 22 2003 Earliest Directional Evolution for Microsatellite Size in Maize PDF Science Retrieved March 3 2014 Pagan Jimenez Jaime R Guachamin Tello Ana M Romero Bastidas Martha E Constantine Castro Angelo R 2015 Late ninth millennium B P use of Zea mays L at Cubilan area highland Ecuador revealed by ancient starches Quaternary International 404 137 155 Bibcode 2016QuInt 404 137P doi 10 1016 j quaint 2015 08 025 ISSN 1040 6182 Los antiguos peruanos comian palomitas de maiz BBC Mundo BBC January 19 2012 Did man follow plants or did plants follow man Tracks of prehistoric man and ways of contact in the Americas according to cultivated plants Case study Maize translated from Portuguese Yumpu 2015 Retrieved October 13 2015 Spielvogel Jackson J March 1 2005 Medieval and Early Modern Times Discovering Our Past Glencoe McGraw Hill School Publishing Company ISBN 978 0 07 868876 8 a b Roney John Winter 2009 The Beginnings of Maize Agriculture Archaeology Southwest 23 1 4 Bengoa Jose 2003 Historia de los antiguos mapuches del sur in Spanish Santiago Catalonia pp 199 200 ISBN 956 8303 02 2 Dillehay Tom D Pino Quivira Mario Bonzani Renee Silva Claudia Wallner Johannes Le Quesne Carlos 2007 Cultivated wetlands and emerging complexity in south central Chile and long distance effects of climate change PDF Antiquity 81 314 949 960 doi 10 1017 s0003598x00096034 S2CID 59480757 a b Perez Alberto E Erra Georgina 2011 Identificacion de maiz de vasijas recuperadas de la Patagonia noroccidental argentina Identifying maize residues in pottery vessels in northwestern Patagonia Argentina Magallania in Spanish 39 2 309 316 doi 10 4067 S0718 22442011000200022 Bird Junius 1946 The Alacaluf In Steward Julian H ed Handbook of South American Indians Bulletin 143 Vol I Bureau of American Ethnology pp 55 79 a b Torrejon Fernando Bizama Fernando Araneda Alberto Aguayo Mauricio Bertrand Sebastien Urrutia Roberto 2013 Descifrando la historia ambiental de los archipielagos de Aysen Chile El influjo colonial y la explotacion economica mercantil republicana siglos XVI XIX Deciphering the environmental history of the Aysen archipelagos Chile Colonial influence and commercial exploitation during the Republican Era XVI XIX centuries Magallania in Spanish 41 1 29 52 doi 10 4067 S0718 22442013000100002 Fussell Betty 1999 Translating Maize into Corn The Transformation of America s Native Grain Social Research 66 1 41 65 JSTOR 40971301 Retrieved September 19 2022 The greatest difference between corn and maize however lies in the symbolic freight that each word carries If north of Mexico European immigrants built an industrial kingdom and a global empire on the economic power of corn in Mesoamerica the Olmec a thousand years before Christ founded a complete universe a language calendar mythos and cosmos on the symbolic power of maize If the one culture diminished a staple food to merchandise the other sanctified it as divine Rebecca Earle The Body of the Conquistador Food Race and the Colonial Experience in Spanish America 1492 1700 New York Cambridge University Press 2012 pp 17 151 Earle The Body of the Conquistador p 5 a b Earle The Body of the Conquistador p 144 Marion Eugene Ensminger and Audrey H Ensminger Foods amp Nutrition Encyclopedia Two Volume Set CRC Press 1994 Page 1104 William L Langer American Foods and Europe s Population Growth 1750 1850 Journal of Social History 8 2 1975 pp 51 66 Pages 58 60 maize n and adj Oxford English Dictionary Online ed Oxford University Press Subscription or participating institution membership required a b Ranum Peter Pena Rosas Juan Pablo Garcia Casal Maria Nieves April 2014 Global maize production utilization and consumption Annals of the New York Academy of Sciences 1312 1 105 112 doi 10 1111 nyas 12396 PMID 24650320 S2CID 4640742 Head John W November 25 2016 International Law and Agroecological Husbandry Building legal foundations for a new agriculture Routledge ISBN 978 1 315 44650 9 a b Ensminger Audrey H 1994 Foods and Nutrition Encyclopedia 2nd ed CRC Press p 479 ISBN 978 0 8493 8980 1 The word maize is preferred in international usage because in many countries the term corn the name by which the plant is known in the United States is synonymous with the leading cereal grain thus in England corn refers to wheat and in Scotland and Ireland it refers to oats Zea mays maize CABI Retrieved September 16 2022 Espinoza Mauricio All Corn Is the Same and Other Foolishness about America s King of Crops Ohio State University College of Food Agricultural and Environmental Sciences Retrieved September 21 2022 a b c corn n 1 Oxford English Dictionary Online ed Oxford University Press Subscription or participating institution membership required Boberg Charles 2010 The English Language in Canada Status History and Comparative Analysis Cambridge University Press p 109 ISBN 978 1 139 49144 0 Rhodes L L Eagles H A 1984 Origins of maize in New Zealand New Zealand Journal of Agricultural Research 27 2 151 156 doi 10 1080 00288233 1984 10430414 Indian corn Merriam Webster Dictionary definition 3 accessed June 7 2012 Rouf Shah Tajamul Prasad Kamlesh Kumar Pradyuman April 4 2016 Maize A potential source of human nutrition and health A review Cogent Food amp Agriculture 2 1 doi 10 1080 23311932 2016 1166995 S2CID 87844060 Fussell Betty 1999 Translating Maize into Corn The Transformation of America s Native Grain Social Research 66 1 41 65 JSTOR 40971301 Retrieved September 19 2022 To say the word corn is to plunge into the tragi farcical mistranslations of language and history If only the British had followed Columbus in phoneticizing the Taino word mahiz which the Arawaks named their staple grain we wouldn t be in the same linguistic pickle we re in today where I have to explain to someone every year that when Biblical Ruth stood in tears amid the alien corn she was standing in a wheat field But it was a near thing even with the Spaniards when we read in Columbus Journals that the grain which the Indians called maiz the Spanish called panizo The Spanish term was generic for the cereal grains they knew wheat millet barley oats as was the Italian term polenta from Latin pub As was the English term corn which covered grains of all kinds including grains of salt as in corned beef French linguistic imperialism by way of a Parisian botanist in 1536 provided the term Turcicum frumentum which the British quickly translated into Turkey wheat Turkey corn and Indian corn By Turkey or Indian they meant not a place but a condition a savage rather than a civilized grain with which the Turks concurred calling it kukuruz meaning barbaric Maize FAO Retrieved September 16 2022 Overview ICAR Indian Institute of Maize Research Retrieved September 16 2022 Maize Association Maize Association Australia Retrieved September 16 2022 The Maize Association of Nigeria honors IITA for supporting the nation s agriculture International Institute of Tropical Agriculture Retrieved September 16 2022 mealie n Oxford English Dictionary Online ed Oxford University Press Subscription or participating institution membership required a b c Wellhausen Edwin John 1952 Races of Maize in Mexico Karl J R January 2012 The Maximum Leaf Number of the Maize Subspecies PDF The Maize Genetics Cooperation Newsletter 86 4 ISSN 1090 4573 Archived from the original PDF on March 3 2016 Retrieved July 5 2013 World s tallest corn towers nearly 14 meters Science News for Students January 6 2017 Retrieved November 10 2021 Stevenson J C Goodman M M 1972 Ecology of Exotic Races of Maize I Leaf Number and Tillering of 16 Races Under Four Temperatures and Two Photoperiods1 Crop Science 12 6 864 doi 10 2135 cropsci1972 0011183X001200060045x Willy H Verheye ed 2010 Growth And Production Of Maize Traditional Low Input Cultivation Soils Plant Growth and Crop Production Volume II EOLSS Publishers p 74 ISBN 978 1 84826 368 0 Assefa Yared Roozeboom Kraig Thompson Curtis Schlegel Alan Stone Loyd Lingenfelser Jane December 16 2013 Corn and Grain Sorghum Comparison All Things Considered Academic Press ISBN 978 0 12 800395 4 Oldenburg Marcus Petersen Arnd Baur Xaver December 13 2011 Maize pollen is an important allergen in occupationally exposed workers Journal of Occupational Medicine and Toxicology 6 32 doi 10 1186 1745 6673 6 32 ISSN 1745 6673 PMC 3269392 PMID 22165847 Karl J R 2007 Jala Maize is Small PDF Maize Genetics MNL 89 e3 Archived from the original PDF on August 8 2017 Retrieved November 19 2015 Grobman Alexander 1961 Races of Maize in Peru Solaimalai A Anantharaju P Irulandi S Theradimani M May 10 2020 Maize Crop Improvement Production Protection and Post Harvest Technology CRC Press ISBN 978 1 000 17695 7 Common Corn Questions and Answers Archived May 1 2012 at the Wayback Machine Iowa State University of Science and Technology Agronomy Extension 2011 Karl J R January 2002 Maize is Not Day Neutral Day Length and Flowering PDF The Maize Genetics Cooperation Newsletter 89 e7 Archived from the original PDF on August 8 2017 Retrieved September 6 2015 Paliwal R L 2000 Tropical maize Improvement and production ISBN 9789251044575 Unique gene combinations control tropical maize response to day lengths Eurekalert org June 14 2011 Retrieved November 14 2013 Elongated mesocotyl1 a phytochrome deficient mutant of maize Brutnell Lab Archived from the original on December 11 2013 Retrieved December 7 2013 News College of Agricultural Consumer amp Environmental Sciences Corn Stalk Lodging PDF Monsanto Imagine October 2 2008 Archived from the original PDF on February 25 2009 Retrieved February 23 2009 Himi E Mares DJ Yanagisawa A Noda K 2002 Effect of grain color gene R on grain dormancy and sensitivity of the embryo to abscisic acid ABA in wheat Journal of Experimental Botany 53 374 1569 74 doi 10 1093 jxb erf005 PMID 12096095 Winkel Shirley B 2001 Flavonoid biosynthesis A colorful model for genetics biochemistry cell biology and biotechnology Plant Physiology 126 2 485 93 doi 10 1104 pp 126 2 485 PMC 1540115 PMID 11402179 a b Chopra S Cocciolone SM Bushman S Sangar V McMullen MD Peterson T 2003 The maize unstable factor for orange1 is a dominant epigenetic modifier of a tissue specifically silent allele of pericarp color1 Genetics journal Genetics 163 3 1135 1146 doi 10 1093 genetics 163 3 1135 PMC 1462483 PMID 12663550 Structural And Transcriptional Analysis Of The Complex P1 wr Cluster In Maize Wolfgang Goettel Joachim Messing Plant amp Animal Genomes XVI Conference Archived February 18 2012 at the Wayback Machine Dong X Braun EL Grotewold E 2001 Functional conservation of plant secondary metabolic enzymes revealed by complementation of Arabidopsis flavonoid mutants with maize genes Plant Physiology 127 1 46 57 doi 10 1104 pp 127 1 46 PMC 117961 PMID 11553733 cite journal title Suppressor of Pericarp Pigmentation 1 SPP1 a novel gene involved in phlobaphene accumulation in maize Zea mays L pericarps last1 Lee first1 E A last2 Harper first2 V journal Maydica year 2002 volume 47 pages 51 58 id INIST 13772300 issue 1 Grotewold Erich Drummond Bruce J Bowen Ben Peterson Thomas 1994 The myb homologous P gene controls phlobaphene pigmentation in maize floral organs by directly activating a flavonoid biosynthetic gene subset Cell 76 3 543 53 doi 10 1016 0092 8674 94 90117 1 PMID 8313474 S2CID 42197232 a b Gray Leaf Spot Severity Increasing Rapidly CropWatch September 17 2015 Retrieved July 24 2021 a b Before applying fungicides to corn Stop Look Consider Integrated Crop Management Iowa State University Extension Retrieved July 24 2021 Irisch Erin E 1997 Class II tassel seed mutations provide evidence for multiple types of inflorescence meristems in maize Poaceae American Journal of Botany 84 11 1502 1515 doi 10 2307 2446611 JSTOR 2446611 PMID 21708555 Montgomery E 1906 What is an ear of corn Popular Science Monthly 68 January Kraig Bruce 2012 Corn Oxford Reference doi 10 1093 acref 9780199734962 001 0001 ISBN 9780199734962 Retrieved December 4 2017 Wani Shabir Samantara Kajal Razzaq Ali Kakani Grihalakshmi Kumar Pardeep 2022 Back to the wild mining maize Zea mays L disease resistance using advanced breeding tools Review Article Molecular Biology Reports Springer Nature B V 1 17 doi 10 1007 s11033 021 06815 x eISSN 1573 4978 ISSN 0301 4851 OCLC 300185386 Brown David November 20 2009 Scientists have high hopes for corn genome The Washington Post Birchler James A Han Fangpu 2009 Maize Centromeres Structure Function Epigenetics Annual Review of Genetics Annual Reviews 43 1 287 303 doi 10 1146 annurev genet 102108 134834 ISSN 0066 4197 PMID 19689211 Welcome to MaizeGDB MaizeGDB Welcome to MaizeSequence org MaizeSequence org Retrieved September 21 2013 Researchers sequence genome of maize a key crop Reuters February 26 2008 Retrieved October 6 2014 Schnable P S Ware D Fulton R S et al 2009 The B73 Maize Genome Complexity Diversity and Dynamics Science 326 5956 1112 5 Bibcode 2009Sci 326 1112S doi 10 1126 science 1178534 PMID 19965430 S2CID 21433160 Feschotte C Pritham E 2009 A cornucopia of Helitrons shapes the maize genome Proceedings of the National Academy of Sciences 106 47 19747 19748 Bibcode 2009PNAS 10619747F doi 10 1073 pnas 0910273106 PMC 2785235 PMID 19926864 Friedman William E Moore Richard C Purugganan Michael D 2004 The evolution of plant development American Journal of Botany Botanical Society of America Wiley 91 10 1726 1741 doi 10 3732 ajb 91 10 1726 ISSN 0002 9122 PMID 21652320 a b Prasanna Boddupalli Bruce Anani Beyene Yoseph Makumbi Dan Gowda Manje Asim Muhammad Martinelli Samuel Head Graham Parimi Srinivas 2022 Host plant resistance for fall armyworm management in maize relevance status and prospects in Africa and Asia Theoretical and Applied Genetics Breeding towards Agricultural Sustainability Springer Science and Business Media LLC 1 20 doi 10 1007 s00122 022 04073 4 ISSN 0040 5752 PMID 35320376 S2CID 247630210 a b c d e Hough Josh Williamson Robert J Wright Stephen I November 23 2013 Patterns of Selection in Plant Genomes Annual Review of Ecology Evolution and Systematics Annual Reviews 44 1 31 49 doi 10 1146 annurev ecolsys 110512 135851 ISSN 1543 592X Jugenheimer Robert W 1958 Agr Dev Paper 62 Hybrid Maize Breeding and Seed Production Rome Food and Agriculture Organization United Nations a b Rosenberg Tina April 9 2014 A Green Revolution This Time for Africa Duvick D N Cassman K G 2009 Post green revolution trends in yield potential of temperate maize in the north central United States Crop Science 39 6 1622 1630 doi 10 2135 cropsci1999 3961622x S2CID 39657597 Archived from the original on November 15 2009 Maiti Ratikanta 2012 Crop Plant Anatomy CABI ISBN 978 1 78064 174 4 a b c James Clive 2016 Global Status of Commercialized Biotech GM Crops 2016 ISAAA Brief 52 2016 ISAAA Archived from the original on May 4 2017 Retrieved August 26 2017 ISAAA Brief 43 2011 Executive Summary retrieved September 9 2012 a b c d e Ostry Vladimir Malir Frantisek Pfohl Leszkowicz Annie 2015 Comparative data concerning aflatoxin contents in Bt maize and non Bt isogenic maize in relation to human and animal health a review Acta Veterinaria Brno University of Veterinary and Pharmaceutical Sciences Brno 84 1 47 53 doi 10 2754 avb201585010047 ISSN 0001 7213 National Agricultural Statistics Service NASS Agricultural Statistics Board US Department of Agriculture Acreage report for 2010 PDF ISAAA Biotech Maize Update 2011 PDF Archived from the original PDF on May 24 2013 Retrieved October 6 2014 ISAAA Pocket K No 2 Plant Products of Biotechnology 2011 Retrieved October 6 2014 Andrew Pollack September 23 2000 Kraft Recalls Taco Shells With Bioengineered Corn The New York Times Chakradhar Thammineni Hindu Vemuri Reddy Palakolanu Sudhakar September 5 2017 Genomic based breeding tools for tropical maize improvement PDF Genetica Springer 145 6 525 539 doi 10 1007 s10709 017 9981 y ISSN 0016 6707 PMID 28875394 S2CID 24074330 Kole Chittaranjan ed 2020 Genomic Designing of Climate Smart Cereal Crops Cham Switzerland Springer ISBN 978 3 319 93380 1 ISBN 978 3 319 93381 8 a b Whipple C J Kebrom T H Weber A L Yang F Hall D Meeley R Schmidt R Doebley J Brutnell T P August 16 2011 grassy tillers1 promotes apical dominance in maize and responds to shade signals in the grasses Proceedings of the National Academy of Sciences 108 33 E506 E512 doi 10 1073 pnas 1102819108 ISSN 0027 8424 PMC 3158142 PMID 21808030 Emma Penrod September 14 2011 Study of corn genetics has implications for biofuel research The Daily Universe a b c Wilkes Garrison March 8 2004 Chapter 1 1 Corn strange and marvelous but is a definitive origin known In Smith C Wayne Betran Javier Runge E C A eds Corn Origin History Technology and Production John Wiley amp Sons pp 3 63 ISBN 978 0 471 41184 0 Hyams Edward 1990 The Last of the Incas The Rise and Fall of an American Empire Dorset Press ISBN 978 0 88029 595 6 a b Wu Chi Chih Diggle Pamela K Friedman William E March 6 2011 Female gametophyte development and double fertilization in Balsas teosinte Zea mays subsp parviglumis Poaceae Sexual Plant Reproduction International Association of Sexual Plant Reproduction Research Springer 24 3 219 229 doi 10 1007 s00497 011 0164 1 ISSN 0934 0882 PMID 21380710 S2CID 8045294 Doebley John F 2004 The genetics of maize evolution PDF Annual Review of Genetics 38 37 59 doi 10 1146 annurev genet 38 072902 092425 PMID 15568971 Wild grass became maize crop more than 8 700 years ago National Science Foundation News Release at Eurekalert March 24 2009 March 23 2009 Retrieved October 6 2014 a b Ranere Anthony J Piperno Dolores R Holst Irene et al 2009 The cultural and chronological context of early Holocene maize and squash domestication in the Central Balsas River Valley Mexico Proceedings of the National Academy of Sciences 106 13 5014 5018 Bibcode 2009PNAS 106 5014R doi 10 1073 pnas 0812590106 PMC 2664064 PMID 19307573 Ranere Anthony J Piperno Dolores R Holst Irene et al 2009 Starch grain and phytolith evidence for early ninth millennium B P maize from the Central Balsas River Valley Mexico Proceedings of the National Academy of Sciences 106 13 5019 5024 Bibcode 2009PNAS 106 5019P doi 10 1073 pnas 0812525106 PMC 2664021 PMID 19307570 Michael Balter Corn It s Not for Cocktails March 23 2009 news sciencemag org Norman H Horowitz George Wells Beadle 1903 1989 PDF National Academy of Sciences Roney p 4 Thomas E Emerson Kristin M Hedman and Mary L Simon Marginal Horticulturalists or Maize Agriculturalists Archaeobotanical Paleopathological and Isotopic Evidence Relating to Langford Tradition Maize Consumption Midcontinental Journal of Archaeology Vol 30 No 1 Spring 2005 pp 67 118 https www jstor org stable 20708222 Evan Peacock Wendell R Haag Melvin L Warren Jr 2005 Prehistoric decline in freshwater mussels coincident with the advent of maize agriculture PDF Conservation Biology 19 2 547 551 doi 10 1111 j 1523 1739 2005 00036 x S2CID 3679709 Fernandez Armesto Felipe 2011 The World A History p 470 Penguin Academics London ISBN 0 205 75930 0 Hill Christina Gish November 20 2020 Returning the three sisters corn beans and squash to Native American farms nourishes people land and cultures The Conversation Retrieved January 9 2021 Mann Charles C July 2011 Cotton or Anchovies and Maize 1491 New Revelations of the Americas Before Columbus 2nd ed New York Vintage Books pp 225 229 ISBN 978 1 4000 3205 1 Diderot Denis December 15 2011 Maize Encyclopedia of Diderot amp d Alembert Collaborative Translation Project Retrieved April 1 2015 Smith C Wayne Betran Javier Runge Edward C A March 8 2004 Corn Origin History Technology and Production John Wiley amp Sons ISBN 978 0 471 41184 0 Brown Robert C Brown Tristan R December 6 2013 Biorenewable Resources Engineering New Products from Agriculture Wiley ISBN 978 1 118 52492 3 Corn Silage Production and Management Penn State Extension Retrieved November 14 2021 Van Devender Karl July 2011 Grain Drying Concepts and Options PDF University of Arkansas Division of Agriculture Retrieved December 15 2013 World Food and Agriculture Statistical Yearbook 2021 Rome FAO 2021 doi 10 4060 cb4477en ISBN 978 92 5 134332 6 S2CID 240163091 a b FAOSTAT FAO Maize production in 2017 Crops Regions Production Quantity from pick lists United Nations Food and Agriculture Organization Statistics Division FAOSTAT 2018 Retrieved March 15 2020 a b c Crop production 2016 PDF US Department of Agriculture August 12 2016 Retrieved April 4 2017 Janssen Kim December 28 2017 Exciting days for corn lovers as corn to become official state grain of Illinois Chicago Tribune Torban Alli December 4 2021 2 The pandemic wreaked havoc on the corn supply chain Axios Retrieved December 7 2021 a b Download Historical Corn Intraday Futures Data CNA PortaraCQG Retrieved May 17 2022 a b Download Historical Chicago Corn JSE Intraday Futures Data CORN PortaraCQG Retrieved May 17 2022 fall armyworm Spodoptera frugiperda J E Smith entnemdept ufl edu Retrieved November 14 2017 Pechan Tibor Ye Lijun Chang Yu min Mitra Anurina Lin Lei Davis Frank M Williams W Paul Luthe Dawn S July 1 2000 A Unique 33 kD Cysteine Proteinase Accumulates in Response to Larval Feeding in Maize Genotypes Resistant to Fall Armyworm and Other Lepidoptera The Plant Cell 12 7 1031 1040 doi 10 1105 tpc 12 7 1031 ISSN 1040 4651 PMC 149047 PMID 10899972 Marra M C Piggott N E Goodwin B K 2012 The impact of corn rootworm protected biotechnology traits in the United States AgBioForum pp 217 230 Archived from the original on August 6 2016 Retrieved October 6 2013 Erin W Hodgson Utah State University Extension and Utah Plant Pest Diagnostic Laboratory Western corn rootworm Ostlie KR et al University of Minnesota Extension Office Last Reviewed 2008 Bt Corn amp European Corn Borer Long Term Success Through Resistance Management Archived September 28 2013 at the Wayback Machine Goss s Wilt of Corn Crop Protection Network Retrieved July 15 2021 Crous Pedro W Groenewald Johannes Z Groenewald Marizeth Caldwell Pat Braun Uwe Harrington Thomas C May 1 2006 Species of Cercospora associated with grey leaf spot of maize Studies in Mycology Westerdijk Institute Elsevier 55 189 197 doi 10 3114 sim 55 1 189 PMC 2104713 PMID 18490979 S2CID 31494639 Jeffrey M Pilcher Maize and the Making of Mexico p 27 The cassava transformation in Africa The Food and Agriculture Organization of the United Nations FAO Solon Robinson Hot Corn Life Scenes in New York Illustrated Series appearing in 1853 in the NY Tribune later as a book a b Chapter 8 Improvement of maize diets from corporate document Maize in human nutrition United Nations Food and Agriculture Organization 1992 Retrieved June 5 2017 Heuze V Tran G Edouard N Lebas F 2017 Maize silage Feedipedia a programme by INRA CIRAD AFZ and FAO https www feedipedia org node 13883 Last updated on June 22 2017 14 24 Heuze V Tran G Edouard N Lebas F 2017 Maize green forage Feedipedia a programme by INRA CIRAD AFZ and FAO https www feedipedia org node 358 Last updated on June 21 2017 10 16 Liggett R Winston Koffler H December 1948 Corn steep liquor in microbiology Bacteriological Reviews 12 4 297 311 doi 10 1128 MMBR 12 4 297 311 1948 PMC 180696 PMID 16350125 Corn for Home Heat A Green Idea That Never Quite Popped March 2 2015 Retrieved July 7 2017 Torres Andres F Slegers Petronella M Noordam Boot Cornelie M M Dolstra Oene Vlaswinkel Louis van Boxtel Anton J B Visser Richard G F Trindade Luisa M March 15 2016 Maize feedstocks with improved digestibility reduce the costs and environmental impacts of biomass pretreatment and saccharification Biotechnology for Biofuels 9 63 doi 10 1186 s13068 016 0479 0 ISSN 1754 6834 PMC 4791978 PMID 26981155 Fuel Ethanol Plants Thermal Kinetics Engineering PLLC Thermal Kinetics Engineering PLLC Retrieved July 7 2017 Mark Clayton January 28 2008 Christian Science Monitor Christian Science Monitor Retrieved October 6 2014 Iowa Renewable Fuels Association Archived from the original on October 11 2014 Retrieved October 6 2014 Hermann Hofbauer Reinhard R Klaus Bosch Reinhard K Christian Aichernig January 2002 Biomass CHP plant Gussing A success story Revista Envio Are Free Trade Agreements Free Are They Development Strategies envio org ni CBOT Corn Futures Contract Overview via Wikinvest About the American Maze The American Maze Company Maize Quest Fun Park Corn Box Archived from the original on October 12 2007 Retrieved October 8 2007 2009 US Corn Stats PDF Iowa Corn Retrieved December 2 2010 United States Department of Agriculture Economic Research Service Corn supply disappearance and share of total corn used for ethanol www ers usda gov datafiles US Bioenergy Feedstocks table05 xls Excel file accessed June 29 2015 a b Hoffman L and A Baker 2011 Estimating the substitution of distillers grains for corn and soybean meal in the U S feed complex United States Department of Agriculture Economic Research Service FDS 11 l 01 62 pp National Nutrient Database for Standard Reference Release 28 United States Department of Agriculture Agricultural Research Service Nutrition facts calories in food labels nutritional information and analysis NutritionData com USDA Table of Nutrient Retention Factors Release 6 PDF USDA USDA December 2007 a b Nutritional Effects of Food Processing NutritionData com Nutrient data laboratory United States Department of Agriculture Retrieved August 10 2016 The origins of maize the puzzle of pellagra EUFIC gt Nutrition gt Understanding Food The European Food Information Council December 2001 Archived from the original on September 27 2006 Retrieved September 14 2006 Staller John Carrasco Michael November 24 2009 Pre Columbian Foodways Interdisciplinary Approaches to Food Culture and Markets in Ancient Mesoamerica Springer Science amp Business Media p 317 ISBN 978 1 4419 0471 3 Chase Allan April 1980 The Legacy of Malthus the social costs of the new scientific racism University of Illinois Press ISBN 978 0 252 00790 3 Precis by Jan Coe Thompson Janice J Manore Melinda Vaughan Linda January 15 2016 Nutrients involved in energy metabolism The Science of Nutrition Pearson Education pp 292 321 ISBN 978 0 13 429880 1 Also ISBN 978 0 321 64316 2 Corn maize Allergy Archived September 30 2008 at the Wayback Machine InformAll Database October 18 2006 Ogren Thomas Leo 2015 The Allergy Fighting Garden Berkeley Ten Speed Press ISBN 9781607744917 Berrin Katherine amp Larco Museum The Spirit of Ancient Peru Treasures from the Museo Arqueologico Rafael Larco Herrera New York Thames and Hudson 1997 Gordon Ken September 28 2019 From oddity to cherished Dublin icon Field of Corn celebrates 25 years The Columbus Dispatch Archived from the original on September 30 2019 Retrieved December 21 2021 Croatian National Bank Kuna and Lipa Coins of Croatia Archived June 22 2009 at the Wayback Machine 1 Lipa Coin Archived June 28 2011 at the Wayback Machine Retrieved on March 31 2009 Further readingAureliano Brandolni Andrea Brandolini 2006 Il mais in Italia storia naturale e agricola Bergamo Italy CRF press Archived from the original on May 31 2009 Retrieved March 14 2009 XII 370 pages and 80 colour pages Byerlee Derek The globalization of hybrid maize 1921 70 Journal of Global History 15 1 2020 101 122 Clampitt Cynthia Maize How Corn Shaped the U S Heartland 2015 Ferro D N amp Weber D C Managing Sweet Corn Pests in Massachusetts Bonavia Duccio May 13 2013 Maize Origin Domestication and Its Role in the Development of Culture Cambridge University Press ISBN 978 1 107 02303 1 External links Wikimedia Commons has media related to Zea mays Wikispecies has information related to Zea mays Maize Genetics and Genomics Database Maize Genetics Cooperation Stock Center Zea mays Germplasm Resources Information Network GRIN Agricultural Research Service ARS United States Department of Agriculture USDA Maize New International Encyclopedia 1905 Corn The Outer Limits ca 1976 Archives of Ontario YouTube Channel Retrieved from https en wikipedia org w index php title Maize amp oldid 1129836365, wikipedia, wiki, book, books, library,

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