Maize ( / m eɪ z / Mayz ; Zea mays subsp. Mays , from Spanish : maize After Taíno mahiz ) Also Known As corn , is a broad bean plant first domesticated by peoples indigenous in southern Mexico [1] about 10,000 years ago . The leafy stalk of the plant produces separate pollen and ovuliferous inflorescences or ears , which are fruits, yielding kernels or seeds.

Maize has become a staple food in many parts of the world, with total production surpassing that of wheat or rice . However, not all of this is consumed directly by humans. Some of the maize production is used for corn ethanol , animal feed and other maize products , such as corn starch and corn syrup . The six major types are corncorn , flint corn , corncob , popcorn , flour corn, and sweet corn . [2]


Most historians believe maize was domesticated in the Tehuacan Valley of Mexico . [4] Recent research in the early 21st century has modified this view somewhat; Scholars now indicate indication adjacent the Balsas River Valley of south-central Mexico as the center of domestication. [5]

An influential 2002 study by Matsuoka et al . It has been shown 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 shows 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 based on a model based on the archaeological record that offers a variety of products in the highlands of Mexico before spreading to the lowlands. [6] [7]

Archaeologist Dolores Piperno has said: [5]

A large corpus of data indicates that it was dispersed into lower Central America by 7600 BP [5600 BC] and had moved into the 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

page needed ]

Since then, even earlier dates have been published. [8]

According to a genetic study by 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 about 6700 years ago. [9] The second wave, about 2000 years ago, through the lowlands of South America. [10]

Before domestication, maize plants grew only small, 25 millimeters (1 in) long corn cobs, and only one per plant. In Spielvogel’s view, many centuries of artificial selection (rather than the current view that was exploited by interplanting with teosinte ) by the indigenous people of the Americas resulted in the development of maize plants capable of growing several cobs per plant, which were usually several centimeters / inches long each. [11] The Olmec and Maya cultivated maize in all types throughout Mesoamerica ; they cooked, ground and processed it through nixtamalization . It was believed that beginning about 2500 BC, the crop spread through much of theAmericas . [12] Research of the 21st century has established even earlier dates. The region developed a trade network based on surplus and varieties of maize crops.

Maize is the most widely grown grain crop in the Americas, with 361 million metric tons grown in the United States in 2014 (production table). Approximately 40% of the crop-130 million tones-is used for corn ethanol . [13] Genetically modified maize made up 85% of the maize planted in the United States in 2009. [14]

Columbian exchange

After the arrival of Europeans in 1492, the Spanish settlers consumed and traveled to Europe . Spanish settlers far preferred wheat bread to maize, cassava , or potatoes. Maize flour could not be Substituted for wheat bread for communion, since in Christian belief only wheat Could UNDERGO transubstantiation and be Transformed into the body of Christ. [15]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 their distinctive physical characteristics and their characteristic personalities.” [16] Despite these worries, Spaniards did not consume maize. Archeological evidence from Florida sites indicate they cultivated it as well. [17]

Maize spread to the rest of the world because of its ability to grow in various climates. It was cultivated in Spain just a few decades after Columbus’ travels and then spread to Italy , West Africa and elsewhere. [17] Sugar-rich varieties called Expired sweet corn are usually grown for human consumption as kernels, while field corn varieties are used for feed animal, various corn-based human food uses (Including grinding into cornmeal or masa , pressing into corn oil , and fermentation and distillation into alcoholic beverages like bourbon whiskey ), and as chemical feedstocks.


The word maize derives from the Spanish form of the indigenous Taíno word for the plant, mahiz . [18] It is known by other names around the world.

The word “corn” outside of North America, Australia, and New Zealand refers to any cereal crop, its meaning understood to vary geographically to refer to the local staple . [19] [20] In the United States, [19] Canada, [21] Australia and New Zealand, [22] corn Primarily means clustering maize; this use started as a shortening of “Indian corn”. [19] “Indian corn” primarily means maize (the staple grain of indigenous Americans ), but can refer to ” flint corn ” for decoration. [23]

In places outside North America, Australia, and New Zealand, corn Often Refers to maize in culinary contexts. The narrower meaning is usually Indicated By Some additional word, as in sweet corn , sweetcorn , corn on the cob , baby corn , making the puffed Known as popcorn and the breakfast cereal Known As cornflakes .

In Southern Africa, maize is commonly called honeyie ( Afrikaans ) or mealie ( English ), [24] words derived from the Portuguese word for maize, milho . [25]

Maize is preferred in formal, scientific, and international use Because It SPECIFICALLY Refers to this one grain Unlike corn , qui: has a complex variety of meanings That vary by context and geographic area. [20] Maize is used by agricultural organizations and research institutes such as FAO and CSIRO . National agricultural and industry associations Often include the word maize In Their name Even In English-speaking countries Where the local, informal word is something other than maize; for example, the Maize Association of Australia, the Indian Maize Development Association, the Kenya Maize Consortium and the Maize Breeders Network, the National Maize Association of Nigeria, the Zimbabwe Seed Maize Association. However, in commodities trading, cornrefers to maize and other grains. quote needed ]

Structure and physiology

The maize plant is often 3 m (10 ft) in height, [26] but some natural strains can grow 12 m (39 ft). [27] The stem is Commonly Composed of 20 internodes [28] of 18 cm (7.1 in) length. [26] A leaf, which grows from each node, is 9 cm (4 in) in width and 120 cm (4 ft) in length.

Ears develop above a few of the leaves in the midsection of the plant, between the stem and leaf sheath, elongating by around 3 millimeters (0.12 in) per day, to a length of 18 cm (7 in) [26] with 60 cm (24 in) being the maximum alleged in the subspecies. [29] They are female inflorescences , commonly called husks. Certain types of maize have been bred to produce many additional developed ears. These are the source of the ” baby corn ” used as a vegetable in Asian cuisine .

The apex of the stem ends in the tassel, an inflorescence of male flowers. When the tassel is 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.

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 fat , and the entire kernel is often referred to as ” seed “. The cob is close to a multiple fruitin structure, except that the individual fruits (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 ear. The maximum size of kernels is reputedly 2.5 cm (1 in). [30] An ear commonly holds 600 kernels. They are of different 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 the mature plant (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 cook.

Planting density affects multiple aspects of maize. Modern farming techniques in developed countries usually rely on dense planting, which produces one ear per stalk. [31] Stands of silage are still denser, [32] and achieve a lower percentage of ears and more plant matter.

Maize is an optional short-day plant [33] and flowers in a number of growing degree days > 10 ° C (50 ° F) in the environment to which it is adapted. [34] The magnitude of the influence of long nights That-have on the number of days must pass That before maize flowers is genetically prescribed [35] and regulated by the phytochrome system. [36] Photoperiodicity can be eccentric in tropical cultivarssuch that the long days of growing up allow the plants to grow so much that they do not have enough time to produce seed before being killed by frost. These attributes, however, can be found in tropical maize for biofuels . [37]

Immature maize shoots accumulate a potent 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 fat, particularly wheat. A mutant 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 mature maize, DIMBOA levels and resistance to the corn borer decline.

Because of its shallow roots, it is susceptible to droughts, it is intolerant of nutrient-deficient soils, and it is prone to being uprooted by severe winds. [38]

While yellow Maizes drift Their color from lutein and zeaxanthin , in red-colored Maizes, the kernel color is due to anthocyanins and phlobaphenes . These latter substances are synthesized in the flavonoids synthetic pathway [39] from polymerization of flavan-4-ols [40] by the expression of myize pericarp color1 (p1) gene [41] which encodes an R2R3 myb -like transcriptional activator [42] of the A1 gene encoding for dihydroflavonol 4-reductase (reducing dihydroflavonols into flavan-4-ols) [43]while another gene (Suppressor of Pericarp Pigmentation 1 or SPP1) acts as a suppressor . [44] 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) modified P1-wr expression to confer pigmentation in kernel pericarp, as well as vegetative tissues, which normally do not accumulate significant amounts of phlobaphene pigments. [41] The Mize P gene encodes a Myb homolog that recognizes the CCT / AACC sequence, in sharp contrast with the C / TAACGG bound by vertebrate Myb proteins. [45]

Abnormal flowers

Maize flowers may be mutated 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. [46] This may cause inflorescences containing both male and female flowers, or hermaphrodite flowers. [47]


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

  • Flour corn: Zea mays var. amylacea
  • Popcorn : Zea mays var. everta
  • Toothed tooth : Zea mays var. indentata
  • Flint corn : Zea mays var. indurata
  • Sweet corn : Zea mays var. saccharata and Zea mays var. rugosa
  • Waxy corn : Zea mays var. ceratina
  • Amylomaize : Zea mays
  • Podcorn : Zea mays var. tunicata Larrañaga ex A. St. Hil.
  • Striped maize: Zea mays var. japonica

This system has been replaced 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. Now, the categories are forms (little used), races, racial complexes, and recently branches.

Maize is a diploid with 20 chromosomes (n = 10). The combined length of the chromosomes is 1500 cM . Some of the maize chromosomes are what are known as “chromosomal knobs”: highly repetitive heterochromatic domains that stain darkly. Individual knobs are polymorphic among strains of both maize and teosinte .

Barbara McClintock used this knob 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. [48]

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 mutant maize. The total collection has nearly 80,000 samples. The bulk of the collection consists of several named genes, plus additional gene combinations and other heritable variants. There are about 1000 chromosomal aberrations (eg, translocations and inversions) and stocks with abnormal chromosome numbers (eg, tetraploids ). Genetic data describing the mutant maize genome can be accessed at MaizeGDB , the Maize Genetics and Genomics Database. [49]

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 was deposited 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 website. [50]

Primary sequencing of the genome was completed in 2008. [51] On November 20, 2009, the consortium published results of its sequencing effort in Science . [52] 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. [53]


Maize reproduces sexually each year. This randomly selects the following generics of the next generation, which is considered to be useful in the production of certain crops (like high yield or good nutrition).

Maize breeding in prehistory resulted in large plants producing large ears. Modern breeding business with individuals who are highly productive in their fields. 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 (CG Hopkins, 1896), hybrids made of selected inbredlines (GH Shull, 1909), and the highly successful double cross hybrids using 4 inbred lines ( DF Jonesit. 1918, 1922). University supported breeding programs were especially important in developing and introducing modern hybrids. (Ref Jugenheimer Hybrid Maize Breeding and Seed Production, 1958) by the 1930s, companies such as Pioneer devoted to the production of hybrid maize had begun to influence long term development. Internationally significant seed banks Such As International Maize and Wheat Improvement Center (CIMMYT) and the US bank at Maize Genetics Cooperation Stock Center University of Illinois at Urbana-Champaign Maintain germplasm major crop for future development.

Since the 1940s, the first strains of the world have been optimized for specific traits, such as yield, nutrition, drought, pest and disease tolerance. Cross-breeding and genetic modification of the crop, pesticide, water and fertilizer. [54]

Global maize program

CIMMYT operates a traditional 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. [54]

Genetic modification

Main article: Transgenic maize

Genetically modified (GM) maize was one of the 26 GM crops grown commercially in 2016. [55] [56] Grown since 1997 in the United States and Canada, 92% of the US maize crop was genetically modified in 2016 [55] [ 57] and 33% of the world maize crop was GM in 2016. [55] [58]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 USA, and insect-resistant corn was grown in Argentina, Australia, Brazil, Canada, Chile, China, Colombia, Czech Republic, Egypt, EU, Honduras, Japan, Korea, Malaysia, Mexico, Netherlands, New Zealand, Philippines, Romania, Russian Federation, South Africa, Switzerland, Taiwan, USA, and Uruguay. [59]

In September, 2000, up to $ 50 million worth of food products Were Recalled due to the presence of StarLink genetically modified corn, qui HAD beens approved only for animal consumption and HAD not-been approved for human consumption, and Was subsequently Withdrawn from the market. [60]


See also: Origin of maize and interaction with teosintes

Maize is the domesticated variant of teosinte . [61] The two seedlings 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. [61]

Several theories have been proposed to the specific origin of maize in Mesoamerica: [62] [63]

  1. It is a direct domestication of a Mexican annual teosinte , Zea mays ssp. parviglumis , native to the Balsas River valley in south-eastern Mexico , with up to 12% of its genetic material obtained from Zea mays ssp. mexicanathrough introgression . This theory was further confirmed by the 2002 study of Matsuoka et al. [6]
  2. It has-been derived from hybridization entre a small domesticated maize (a Slightly changed form of a wild maize) and a teosinte of section Lush , Either Z. luxurians gold Z. diploperennis .
  3. It has undergone two or more domestications of a wild maize or of a teosinte. (The term “teosinte” describes all species and subspecies in the genus Zea , excluding Zea mays ssp mays .)
  4. It has evolved from a hybridization of Z. diploperennis by Tripsacum dactyloides .

In the late 1930s, Paul Mangelsdorf suggests 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. [62] : 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. [62] : 10 It is supported experimentally and by recent studies of the plants’ genomes. Teosinte and maize are able to 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
  3. how domestication could have proceeded before leaving the face of the world 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 to have started 7,500 to 12,000 years ago. Research originated from the 1950s to 1970s, and was 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 are known to have been there.

Connection with ‘parviglumis’ subspecies

Genetic studies 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 relative wild crop teosinte genetically most similar to modern maize. [64]This has been confirmed by further more recent studies, which has made this hypothesis somewhat more complex. Archaeobotanical studies published in 2009 Balsas River Valley as the most 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 Iguala, Guerrero . [65] [66] [67]

Also, Doebley was part of the team that was credited with first finding, back in 2002, which had been domesticated only once, about 9000 years ago, and then spread throughout the Americas. [6] [68]

A primitive corn was 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 the caves near Tehuacan , Puebla, ca. 3,450 BC. [12]

Maize pollen dated to 7300 cal BP from San Andres, Tabasco , on the Caribbean coast has also been recovered. [66]

As maize was introduced to new cultures, new uses have been developed and improved. Maize was the staple food, a major staple – along with squash , Andean region potato , quinoa , beans , and amaranth – 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.

It is unknown what is its domestication, because it is difficult to obtain directly, as it is enclosed in a very hard bivalve shell. It is possible that, early on, teosinte may have been gathered as preferred feed for domestic animals.

Also, back in 1939, George Beadle demonstrated that the kernels of teosinte are readily “popped” for human consumption, like modern popcorn. [69] Some have argued that it would have taken too many generations of wide breeding , compressed ears for efficient cultivation. However, studies of the hybrids made by intercrossing teosinte and modern maize suggest this objection is not well founded.

Spreading to the north

Around 2500 BC, maize began to spread to the north; It was first cultivated in New Mexico and Arizona, about 2100 BC. [70]

During the first millennium AD, maize cultivation spread more widely in the north. In particular, the large-scale adoption of maize farming and consumption in eastern North America took place on AD 900. Native Americans cleared wide forest and grassland areas for the new crop. [71]

In 2005, research by the USDA Forest Service suggéré que la 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 , qui are very sensitive to environmental changes. [72]



Because it is cold-intolerant, in the temperate areas maize must be planted in the spring. Its root system is shallow, so the plant is dependent on soil moisture. As a C4 plant (a plant that uses C4 carbon fixation ), maize is a more effective water-efficient crop than C3 plants (plants that use C3 carbon fixation ) as small grains, 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 were “knee-high by the Fourth of July “, although modern hybridsgenerally 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 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 moisture is shown in many parts of Africa , where periodic drought often causes maize crop failure and consequent famine.. Although it is grown in hot, hot climates, it has been said to be cold, hot, dry or wet conditions, it is an extremely versatile crop. [73]

Maize was planted by the Native Americans in three Sisters . Maize provided support for beans , and the beans provided by nitrogen derived from nitrogen-fixing rhizobia bacteria which live on the roots of beans and other vegetables ; and squashes provided ground cover to prevent and evaporation by providing shade over the soil. [74]This method was replaced by single species hill planting where each hill 60-120 cm (2.0-3.9 ft) was used by home gardeners. A later technique was “checked maize”, where hills were placed 40 in (1.0 m) apart in each direction, allowing cultivators to run through the field in two directions. In more arid lands, this field has been planted in the bottom of 10-12 cm (3.9-4.7 in) deep furrows to collect water. Modern technique seedlings maize in rows that allows for cultivation while the plant is young, but the hill technique is still used in the fields of some Native American reservations. When maize is planted in rows, it also allows for planting of other crops. [75]

In MOST areas today, maize grown in residential gardens is still Often planted manually with a hoe , whereas maize grown Commercially is no longer planted manually Rather goal is planted with a plant . In North America, fields are planted in a TWO- Often crop rotation with a nitrogen-fixing crop, Often alfalfa in cooler climates and soybeans in regions with summers along. Sometimes a third crop, winter wheat , is added to the rotation.

Many of the maize varieties are grown in the United States and Canada are hybrids. Often the types 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.

In the midwestern United States, low-till or no-till farming techniques are usually used. In low-till, fields are covered once or twice, with a prior implementation or before harvesting. The fields are planted and fertilized . Weeds are controlled through the use of herbicides , and no cultivation is done during the growing season. This technique 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.


Before the 20th century, all maize harvesting by manual labor , by grazing , or by some combination of those. Whether the ears were hand-picked and the stover was grazed, gathered together, 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 manual harvesting to Entirely Entirely mechanized, are still in use to Some degree, as Appropriate To Each farm’s needs , the ALTHOUGH Thoroughly mechanized versions predominate, As They offer the lowest unit costswhen scaled to large farm operations. For small farms, their unit can be too high, and their fixed cost can not be reduced .

Before World War II , most in North America was harvested by hand. This involved large numbers of workers and associated social events (husking or shucking bees ). From the 1890s onward, some machinery has become partially mechanized, such as one-and two-row mechanical pickers (picking the ear, leaving the stover ) and corn binders, which are reaper-bindersspecifically designed for maize (for example , Video on YouTube ). The last produce sheaves that can be shocked. By hand or mechanical picker, the whole ear is harvested, which then requires a separate operation of a maize sheller to remove the kernels from the ear. Whole ears of maize are often stored in these cribs , and they are a sufficient supply for some livestock feeding. 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 head (with points and snapshots instead of a reel) does not cut the stalk; it simply pulls the stalk down. The stalk continues downward and is in a state of flux on the ground, where it is usually left to become organic matter for the soil. The ear of maize is too wide to pass between the slots and the sneakers of the stalk away, leaving only the ear and husk to enter the machinery. The combine separates the husk and the cob, keeping the kernels alone.

When maize is a silage crop, the whole plant is usually chopped at once with a harvester drill (chopper) and ensiled in silos or polymer wrappers. Ensiling of sheaves is usually common in some regions but has become uncommon.

For storing grain in bins, the moisture of the grain must be sufficiently low to avoid spoiling. If the moisture content of the 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 propane or natural gas and electricity to power the blowers. [76]


Maize is widely cultivated throughout the world, and a greater weight of maize is produced each year than any other grain. [77] In 2014, total world production was 1.04 billion tonnes , led by the United States with 35% of the total (table). China produced 21% of the global total.

Maize production – 2014 [78]
Country Production(millions oftonnes )
 United States 361.1
 china 215.6
 brazil 79.9
 argentina 33.1
 Ukraine 28.5
 india 23.7
 mexico 23.3

United States

Main article: Corn production in the United States

In 2016, corn (maize) production was forecast to be over 15 billion bushels , an increase of 11% over 2014 American production. [79] Based on conditions as of August 2016, the expected yield would be the highest ever for the United States. [79] The area of ​​harvested maize was forecast to be 87 million acres, an increase of 7% over 2015. [79]



  • African armyworm ( Spodoptera exempta )
  • African sugarcane borer (Eldana saccharina)
  • 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 ) and Southern corn rootworm ( D. undecimpunctata howardi )
  • Corn silkfly ( Euxesta stigmatias )
  • Asian corn borer ( Ostrinia furnacalis )
  • European corn borer ( Ostrinia nubilalis ) (ECB)
  • Fall armyworm ( Spodoptera frugiperda ) Some sweet corn has developed partial resistance to fallows by producing a unique 33-kD proteinase that significantly delays fall army worm growth. [80] [81]
  • Earworm Corn / 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 consequent large-scale production of pest, [82] [83] [84] 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.


Main article: List of maize diseases
  • Rust
  • Corn smut or common smut ( Ustilago maydis ): a fungal disease, known in Mexico as eightlacoche , which is prized by some as a gourmet delicacy in itself
  • Northern corn leaf blight (Purdue Extension site) (Pioneer site)
  • 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 )
  • Gray leaf spot
  • Río Cuarto virus virus (MRCV)
  • Stalk rot
  • Ear rot


Human food

Maize and cornmeal (ground maize) is a staple food in many regions of the world.

Maize is central to Mexican food . Virtually every dish in Mexican kitchen uses maize. In the form of grain or cornmeal, maize is the main ingredient of tortillas , tamales , pozole , atole and all the dishes based on them, like tacos , quesadillas , chilaquiles , enchiladas , tostadas and many more. In Mexico, a fungus of maize, known as eightloche is considered a delicacy.

Introduced into Africa by the Portuguese in the 16th century, maize has become Africa’s most important staple food crop. [85] Maize meal is made into a thick porridge in many cultures: from the polenta of Italy, the angu of Brazil, the mămăligă of Romania , the cornmeal of the US (and hominy grits in the South) or the food called mealie pap in South Africa and sadza , nshimaand ugali in other parts of Africa. Maize meal is also used as a replacement for wheat flour, to makecornbread and other baked products. Masa (cornmeal treated with limewater ) is the main ingredient for tortillas , atole and many other dishes of Central American food.

Popcorn consists of kernels of certain types that explode when heated, forming fluffy pieces that are eaten as a snack. Roasted dried maize ears with semihardened kernels, a popular snack food in Vietnam. Cancha , which are roasted maize chulpe kernels, are a very popular snack food in Peru, and also appears in traditional Peruvian ceviche . An unleavened bread called makki di roti is a popular bread eaten in the Punjab region of India and Pakistan.

Chicha and chicha morada (purple shisha) are usually made from particular types of maize. The first one is fermented and alcoholic, the second is a soft drink commonly drunk in Peru.

Cornflakes are a common breakfast cereal in North America and the United Kingdom, and found in many other countries all over the world.

Maize can be prepared as hominy , in which the kernels are soaked with lye in a process called nixtamalization ; gold grits , which are coarsely ground hominy. These are commonly eaten in the Southeastern United States , from Native Americans , who called the dish sagamite .

The Brazilian dessert canjica is made by boiling maize kernels in sweetened milk. 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 roaming the right 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. 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 stalls seen on the streets of big cities today. [86] The cooked, unripe kernels can also be used as a vegetable , salads , garnishes , etc. Alternatively, the raw unripe kernels may be grated off the cobs and processed into a variety of cooked dishes, such as maize puree , tamales,pamonhas , curau , cakes , ice creams , etc.

Maize is a major source of starch . Cornstarch (maize flour) is a major ingredient in home cooking and many industrialized food products. Maize is also a major source of cooking oil ( corn oil) and maize gluten. 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 sourced from Bourbon whiskey . Maize is sometimes used as a starch source for beer. Within the United States, the use of maize for human consumption is 1 / 40th of the amount grown in the country. In the United States and Canada, maize is mostly grown to feed livestock , as drilling, silage (made by fermentation of chopped green cornstalks), or grain. Maize meal is also a significant ingredient of some commercial pet food products, such as dog food .

Nutritional value

Raw, yellow, sweet corn kernels are composed of 76% water, 19% carbohydrates , 3% protein , and 1% fat (table). In a 100- gram serving, myize kernels provide 86 calories and are a good source (10-19% of the Daily Value ) of the B vitamins , thiamin , niacin , pantothenic acid (B5) and folate (right table for raw, uncooked kernels, USDA Nutrient Database). In moderate water equivalent, They aussi supply dietary fiber and the essential minerals , magnesium andphosphorus and other nutrients are in low amounts (table).

Maize has suboptimal amounts of the essential amino acids tryptophan and lysine , which accounts for its lower status as a protein source. [87]

Feed and fodder for livestock

See also: Corn stover § Uses

Maize is a major source of both feed grain 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 a crib , or they can be shelled for storage in a grain bin . The farm that consumes the feed can produce it, buy 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) gold soil amendment. When the whole maize plant (grain more 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 boreholes for ruminants. [88] Before the advent of Widespread ensilaging, It was traditional to gather the corn into shocks after-harvesting, Where It further Top dried. With or without a subsequent move to the cover of a barn, it was then stored for weeks to be fed to the livestock. Today ensilaging can occur in siloesbut also in silage wrappers. However, in the tropics can be harvested year-round and fed as green drilling to the animals. [89]


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

The corn steep liquor , a plentiful watery byproduct of maize wet milling process, is widely used in the biochemical industry and research as a medium culture to grow many kinds of microorganisms . [90]

Chrysanthemum is found in purple corn and is used as a food coloring.


See also: Corn ethanol and corn stover

“Feed maize” is being used for heating; [91] Specialized corn stoves (similar to wood stoves ) are available and wears 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 using maize kernels as a fuel. They feature a large hopper that feeds the uniformly sized maize kernels (gold wood pellets or cherry pits) into the fire.

Maize is used as a feedstock for the production of ethanol fuel . [92] When considering where to construct an ethanol plant, one of the site selection criteria is to ensure there is locally available feedstock. [93] Ethanol is mixed with gasoline to reduce the amount of pollutants emitted when used to fuel motor vehicles. High fuel prices in ethanol, which in turn to farmers for maize. This is one of the most profitable maize crops in modern history for farmers. Because of the relationship between fuel and maize, the prices paid for the crop tend to the price of oil. quote needed ]

The price of food is affected by the use of maize for biofuel production. The cost of transportation, production, and marketing are large (80%) of the price of food in the United States. Higher energy costs affect these costs, especially transportation. The increase in food prices has been increased. The effect of biofuel production on other food crops is indirect. Use of maize for biofuel production increases 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 other food crops and increases their prices. [94] [95]

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 in the production of fuel ethanol.

A biomass gasification power plant in Strem near Güssing , Burgenland , Austria, began in 2005. Research is being done to make diesel out of the biogas by the Fischer Tropsch method.

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’ need of energy, the need to maintain, in regions such as Latin America, the food habits and culture of the essence of civilizations such as NAFTA , January 2008, the first originated in Mesoamerica, of maize among the commercial agreements of NAFTANAFTA “opened the doors of the United States of America, 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 from 8.1 million in 1993 to 6.8 million in 2002 Many of those who found themselves working with small scale maize growers. “). [96] However, introduction to the northern latitudes of the US of tropical maize for biofuels , and not for human or animal consumption, may potentially alleviate this.

As a result of the US federal government announcing its production target of 35 billion US gallons (130,000,000 m 3 ) of biofuels by 2017, ethanol production will grow to 7 trillion US gallons (26,000,000 m 3 ) by 2010, up from 4.5 trillion in 2006 , boosting ethanol’s share of demand in the US from 22.6 percent to 36.1 percent. [97]


Maize is Bought and sold by investors and price Speculators have a tradable commodity using corn futures contracts . These “future” 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. [98]

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.

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

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, which was created in Maze in Pennsylvania in 1993. [99] 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.

Maize kernels can be used in sandboxlike enclosure for children’s play. [100]

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

Maize is used as a fish bait , called “dough balls”. It is particularly popular in Europe for coarse fishing .

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

United States usage breakdown

The breakdown of use of the 12.1-billion- bushel (307-million-ton) 2008 US maize crop was as follows, according to the World Agricultural Supply and Demand Estimates Report by the USDA. [101]

use Amount
million bushels million tons 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, cornmeal, beverage alcohol 327 8.3 2.7

In the US since 2009/2010, maize feedstock used for ethanol production has been exceeded directly for livestock feed; Maize use for fuel ethanol was 5.130 million bushels (130 million tonnes) in the 2013/2014 marketing year. [102]

A fraction of the feedstock drystock used for ethanol production is usedfully 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. [103] Because starch utilization in fermentation for ethanol production leaves other grain constituents, the feed value 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. [103]

Comparison to other staple foods

Nutrient contents in% DV of common foods (raw, uncooked) per 100 g
[ show ] Protein Fiber Vitamins Minerals

Ch. = Choline; Ca = Calcium; Fe = Iron; Mg = Magnesium; P = Phosphorus; K = Potassium; Na = Sodium; Zn = Zinc; Cu = Copper; Mn = Manganese; Se = Selenium; % DV =% daily value ie% 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. [104] [105] Cooking reduction =% Maximum typical reduction in nutrients due to boiling without draining for ovo-lacto-vegetables group [106] [107] Q = Quality of Protein in Terms of Complementary Control for Digestability. [107]

The following table shows the nutrient content of maize and major staple foods in a raw harvested form. Raw forms are not edible and can not 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 those presented in the table below.

Nutrient content of major staple foods per 100 g portion [108]
Nutrient component: Maize / Corn [A] Rice (white) [B] Rice (brown) [I] Wheat [C] Potato [D] Cassava [E] Soybean (Green) [F] Sweet potato [G] Yam [Y] Sorghum [H] Plantain [Z] GDR
Water (g) 10 12 10 13 79 60 68 77 70 9 65 3000
Energy (kJ) 1528 1528 1549 1369 322 670 615 360 494 1419 511 8368 to 10.460
Protein (g) 9.4 7.1 7.9 12.6 2.0 1.4 13.0 1.6 1.5 11.3 1.3 50
Fat (g) 4.74 0.66 2.92 1.54 0.09 0.28 6.8 0.05 0.17 3.3 0.37
Carbohydrates (g) 74 80 77 71 17 38 11 20 28 75 32 130
Fiber (g) 7.3 1.3 3.5 12.2 2.2 1.8 4.2 3 4.1 6.3 2.3 30
Sugar (g) 0.64 0.12 0.85 0.41 0.78 1.7 0 4.18 0.5 0 15
Calcium (mg) 7 28 23 29 12 16 197 30 17 28 3 1000
Iron (mg) 2.71 0.8 1.47 3.19 0.78 0.27 3.55 0.61 0.54 4.4 0.6 8
Magnesium (mg) 127 25 143 126 23 21 65 25 21 0 37 400
Phosphorus (mg) 210 115 333 288 57 27 194 47 55 287 34 700
Potassium (mg) 287 115 223 363 421 271 620 337 816 350 499 4700
Sodium (mg) 35 5 7 2 6 14 15 55 9 6 4 1500
Zinc (mg) 2.21 1.09 2.02 2.65 0.29 0.34 0.99 0.3 0.24 0 0.14 11
Copper (mg) 0.31 0.22 0.43 0.11 0.10 0.13 0.15 0.18 0.08 0.9
Manganese (mg) 0.49 1.09 3.74 3.99 0.15 0.38 0.55 0.26 0.40 2.3
Selenium (μg) 15.5 15.1 70.7 0.3 0.7 1.5 0.6 0.7 0 1.5 55
Vitamin C (mg) 0 0 0 0 19.7 20.6 29 2.4 17.1 0 18.4 90
Thiamin (B1) (mg) 0.39 0.07 0.40 0.30 0.08 0.09 0.44 0.08 0.11 0.24 0.05 1.2
Riboflavin (B2) (mg) 0.20 0.05 0.09 0.12 0.03 0.05 0.18 0.06 0.03 0.14 0.05 1.3
Niacin (B3) (mg) 3.63 1.6 5.09 5.46 1.05 0.85 1.65 0.56 0.55 2.93 0.69 16
Pantothenic acid (B5) (mg) 0.42 1.01 1.49 0.95 0.30 0.11 0.15 0.80 0.31 0.26 5
Vitamin B6 (mg) 0.62 0.16 0.51 0.3 0.30 0.09 0.07 0.21 0.29 0.30 1.3
Folate Total (B9) (μg) 19 8 20 38 16 27 165 11 23 0 22 400
Vitamin A (IU) 214 0 0 9 2 13 180 14187 138 0 1127 5000
Vitamin E , alpha-tocopherol (mg) 0.49 0.11 0.59 1.01 0.01 0.19 0 0.26 0.39 0 0.14 15
Vitamin K1 (μg) 0.3 0.1 1.9 1.9 1.9 1.9 0 1.8 2.6 0 0.7 120
Beta-carotene (μg) 97 0 5 1 8 0 8509 83 0 457 10,500
Lutein + zeaxanthin (μg) 1355 0 220 8 0 0 0 0 0 30
Saturated fatty acids (g) 0.67 0.18 0.58 0.26 0.03 0.07 0.79 0.02 0.04 0.46 0.14
Monounsaturated fatty acids (g) 1.25 0.21 1.05 0.2 0.00 0.08 1.28 0.00 0.01 0.99 0.03
Polyunsaturated fatty acids (g) 2.16 0.18 1.04 0.63 0.04 0.05 3.20 0.01 0.08 1.37 0.07
A yellow corn B raw unenriched long grain white rice
C hard red winter wheat A 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
I raw long-grain brown rice



Main article: Pellagra

When it was first introduced into farming systems other than 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 commonly seen among the indigenous Americans, for whom maize was the principal staple food. [109]

It was eventually discovered that the indigenous Americans had learned to soak in alkali- water-made with ashes and lime ( calcium oxide ) since at least 1200-1500 BC by Mesoamericans and North Americans-which liberates the B-vitamin niacin , the lack of which was the underlying cause of the condition known as pellagra . [110]

Maize was introduced into the diet of nonindigenous Americans without the need for cultural knowledge of the Americas. In the late 19th century, epidemic proportions of the southern US, as shown by the results of the deficiency theory (which was eventually shown to be true) , and the germ theory said that pellagra was caused by a germ transmitted by stable flies. A third theory, sponsored by the Charles Davenport eugenicist , held that they only contracted pellagra if they were susceptible to it due to certain “constitutional, inheritable” traits of the affected individual. [111]

Once alkali processing and dietary variety are understood and applied, pellagra disappeared in the developed world. The development of high lysine and the promotion of a 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. Thompson, Janice J .; Manore, Melinda; Vaughan, Linda (15 January 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 . </ Ref>


Maize contains lipid transfer protein , an indigestible protein that survives cooking. This protein has been linked to a rare and understated allergy to maize in humans. [112] 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.


Maize has been an essential crop in the Andes since the pre-Columbian era . The Moche culture from Northern Peru made from ceramics from earth, water, and fire. This pottery was a sacred substance, formed in significant shapes and used to represent important themes. Maize was naturally anthropomorphically represented. [113]

In the United States, the United States Capitol Building. Maize itself is sometimes used for temporary architectural design when it comes to local agricultural productivity and culture. Bundles of dried maize are often displayed 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 walls and ears of color to create a design that is recycled annually. Another example is the Well Known Field of Corn in Dublin, Ohio, where hundreds of concrete ears of corn lay in a grassy field.

A maize stalk with two ripe ears is depicted on the reverse of the Croatian 1 lipa coin, minted since 1993. [114]