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97-469: The Monongahela practiced maize agriculture, and lived in well laid out villages, some of which consisted of as many as 50-100 structures. They traded with other Indian groups who in turn traded with Europeans. The Monongahela seem to have disappeared some time during the 1620s or 1630s before having significant direct contact with Europeans. Many scholars believe this to be the result of the spread of European infectious diseases . Others believe that most of

194-427: A hierarchical pattern . Other terms for a drainage basin are catchment area , catchment basin , drainage area , river basin , water basin , and impluvium . In North America, they are commonly called a watershed , though in other English-speaking places, "watershed" is used only in its original sense, that of the drainage divide line. A drainage basin's boundaries are determined by watershed delineation ,

291-437: A common task in environmental engineering and science. In a closed drainage basin, or endorheic basin , rather than flowing to the ocean, water converges toward the interior of the basin, known as a sink , which may be a permanent lake, a dry lake , or a point where surface water is lost underground . Drainage basins are similar but not identical to hydrologic units , which are drainage areas delineated so as to nest into

388-814: A conventional breeding program to provide optimized strains. The program began in the 1980s. Hybrid seeds are distributed in Africa by its Drought Tolerant Maize for Africa project. Tropical landraces remain an important and underused source of resistance alleles – both those for disease and for herbivores . Such alleles can then be introgressed into productive varieties. Rare alleles for this purpose were discovered by Dao and Sood, both in 2014. In 2018, Zerka Rashid of CIMMYT used its association mapping panel, developed for tropical drought tolerance traits. to find new genomic regions providing sorghum downy mildew resistance , and to further characterize known differentially methylated regions . Genetically modified maize

485-403: 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

582-454: A drainage basin, and there are different ways to interpret that data. In the unlikely event that the gauges are many and evenly distributed over an area of uniform precipitation, using the arithmetic mean method will give good results. In the Thiessen polygon method, the drainage basin is divided into polygons with the rain gauge in the middle of each polygon assumed to be representative for

679-540: A drainage boundary is referred to as watershed delineation . Finding the area and extent of a drainage basin is an important step in many areas of science and engineering. Most of the water that discharges from the basin outlet originated as precipitation falling on the basin. A portion of the water that enters the groundwater system beneath the drainage basin may flow towards the outlet of another drainage basin because groundwater flow directions do not always match those of their overlying drainage network. Measurement of

776-427: A group signature, thus permitting identification of individual or related village removals that may be synonymous with tribes." Monongahela houses were small oval to round shaped and were built within palisaded villages with a central plaza . These villages' entry point often had a maze-like structure that overlapped the stockaded outer walls. Differing from Fort Ancient methods, some entrances were covered. Some of

873-408: A large cob. Yellow maizes derive their color from carotenoids ; red maizes are colored by anthocyanins and phlobaphenes ; and orange and green varieties may contain combinations of these pigments. Maize has short-day photoperiodism , meaning that it requires nights of a certain length to flower. Flowering further requires enough warm days above 10 °C (50 °F). The control of flowering

970-499: A measure of protection against a wide range of pests. Because of its shallow roots, maize is susceptible to droughts, intolerant of nutrient-deficient soils, and prone to being uprooted by severe winds. Maize is diploid with 20 chromosomes . 83% of allelic variation within the genome derives from its teosinte ancestors, primarily due to the freedom of Zea species to outcross . Barbara McClintock used maize to validate her transposon theory of "jumping genes", for which she won

1067-602: A multi-level hierarchical drainage system . Hydrologic units are defined to allow multiple inlets, outlets, or sinks. In a strict sense, all drainage basins are hydrologic units but not all hydrologic units are drainage basins. About 48.71% of the world's land drains to the Atlantic Ocean . In North America , surface water drains to the Atlantic via the Saint Lawrence River and Great Lakes basins,

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1164-638: A place but a condition, a savage rather than a civilized grain". International groups such as the Centre for Agriculture and Bioscience International consider maize the preferred common name. The word maize is used by the UN's Food and Agriculture Organization , and in the names of the International Maize and Wheat Improvement Center of Mexico, the Indian Institute of Maize Research,

1261-601: A plant that uses C 4 carbon fixation , maize is a considerably more water-efficient crop than plants that use C 3 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

1358-791: A smokehouse. Monongahela pottery and tools were well crafted and included decorated clay pipes for smoking. Glass trade beads have been found at some villages, although there is no record of European contact. Like its sister culture the Fort Ancient , the Monongahela made a leap in agriculture by adopting seed crops from Mesoamerica, which had been obtained through their ancestral trade network. The women cultivated varieties of crops such as maize , beans , squash, and sunflower , collecting their seeds to use in subsequent years. They also collected wild plant foods, such as nuts and berries, to complete their diets. As with many contemporary groups to

1455-550: Is a Late Woodland horizon that coincides with the Mingo homeland and distinguishes it from the Iroquois League homeland, centered in present-day New York state. Monongahela villages originated on flood plains, but by 1250, the people had migrated to the watershed highlands and often lived on gaps between ridges. Archaeologists speculate that the move to these areas, and construction of larger, fortified villages at this time

1552-549: Is a major pest of maize in Asia. Drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth , or flows into another body of water , such as a lake or ocean . A basin is separated from adjacent basins by a perimeter, the drainage divide , made up of a succession of elevated features, such as ridges and hills . A basin may consist of smaller basins that merge at river confluences , forming

1649-426: Is a problem in Asia. Some fungal diseases of maize produce potentially dangerous mycotoxins such as aflatoxin . In the United States, major diseases include tar spot , bacterial leaf streak , gray leaf spot , northern corn leaf blight, and Goss's wilt ; in 2022, the most damaging disease was tar spot, which caused losses of 116.8 million bushels . Maize sustains a billion dollars' worth of losses annually in

1746-674: Is a tall stout grass that produces cereal grain . It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte . Native Americans planted it alongside beans and squashes in the Three Sisters polyculture . The leafy stalk of the plant gives rise to male inflorescences or tassels which produce pollen , and female inflorescences called ears . The ears yield grain, known as kernels or seeds. In modern commercial varieties, these are usually yellow or white; other varieties can be of many colors. Maize relies on humans for its propagation. Since

1843-408: Is composed of transposons , contains 32,540 genes. Much of it has been duplicated and reshuffled by helitrons , a group of transposable elements within maize's DNA. 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

1940-537: Is cultivated throughout the world; a greater weight of maize is produced each year than any other grain. In 2020, world production was 1.1 billion tonnes. It is afflicted by many pests and diseases ; two major insect pests, European corn borer and corn rootworms , have each caused annual losses of a billion dollars in the US. Modern plant breeding has greatly increased output and qualities such as nutrition, drought tolerance, and tolerance of pests and diseases. Much maize

2037-414: 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

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2134-533: Is now genetically modified . As a food, maize is used to make a wide variety of dishes including Mexican tortillas and tamales , Italian polenta , and American hominy grits . Maize protein is low in some essential amino acids , and the niacin it contains only becomes available if freed by alkali treatment . In Mesoamerica, maize is deified as a maize god and depicted in sculptures. Maize requires human intervention for it to propagate. The kernels of its naturally-propagating teosinte ancestor fall off

2231-487: Is referred to as " watershed management ". In Brazil , the National Policy of Water Resources, regulated by Act n° 9.433 of 1997, establishes the drainage basin as the territorial division of Brazilian water management. When a river basin crosses at least one political border, either a border within a nation or an international boundary, it is identified as a transboundary river . Management of such basins becomes

2328-468: Is set genetically; the physiological mechanism involves the phytochrome system. Tropical cultivars can be problematic if grown in higher latitudes, as the longer days can make the plants grow tall instead of setting seed before winter comes. On the other hand, growing tall rapidly could be convenient for producing biofuel. Immature maize shoots accumulate a powerful antibiotic substance, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one ( DIMBOA ), which provides

2425-498: 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 can thrive in cold, hot, dry or wet conditions, meaning that it is an extremely versatile crop. Maize was planted by the Native Americans in small hills of soil, in the polyculture system called the Three Sisters . Maize provided support for beans ;

2522-614: Is the Dead Sea . Drainage basins have been historically important for determining territorial boundaries, particularly in regions where trade by water has been important. For example, the English crown gave the Hudson's Bay Company a monopoly on the fur trade in the entire Hudson Bay basin, an area called Rupert's Land . Bioregional political organization today includes agreements of states (e.g., international treaties and, within

2619-557: Is the domesticated variant of the four species of teosintes , which are its crop wild relatives . The teosinte origin theory was proposed by the Russian botanist Nikolai Ivanovich Vavilov in 1931, and the American Nobel Prize -winner George Beadle in 1932. 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

2716-405: Is the leaf most closely associated with a particular developing ear. This leaf and those above it contribute over three quarters of the carbohydrate ( starch ) that fills the grain. The grains are usually yellow or white in modern varieties; other varieties have orange, red, brown, blue , purple , or black grains. They are arranged in 8 to 32 rows around the cob; there can be up to 1200 grains on

2813-548: Is the recently found Wana village site, which was revealed by infrared photography . A field test at the Wana site confirmed pottery, shell, and flint present. It has not yet been studied. The LaPoe (46Mg21) village complex in Monongalia County, West Virginia is a circular village occupied during the 16th and 17th centuries, with trade items recovered. Nearby LaPoe, 46Mg18 is a stone burial mound . Also located at LaPoe

2910-645: Is the village site 46Mg20. Pyle Farm, 46Mg15, is a late prehistoric village site that is located in the Osage USGS Quadrangle. In addition, hundreds of undocumented archeological sites exist in the Dunkard Creek Watershed of Greene County, Pennsylvania and Monongalia County, West Virginia . Monongahela pottery was constructed using the coil method, tempered using crushed igneous rock (e.g., granite) or quartz temper, and usually decorated with cordmarking. (Mayer-Oakes’ 1955) To quote

3007-713: The African Great Lakes , the interiors of Australia and the Arabian Peninsula , and parts in Mexico and the Andes . Some of these, such as the Great Basin, are not single drainage basins but collections of separate, adjacent closed basins. In endorheic bodies of water where evaporation is the primary means of water loss, the water is typically more saline than the oceans. An extreme example of this

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3104-612: The Balsas River valley in Mexico's southwestern highlands, as the crop wild relative genetically most similar to modern maize. The middle part of the short Balsas River valley is the likely location of early domestication. 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 . Doebley and colleagues showed in 2002 that maize had been domesticated only once, about 9,000 years ago, and then spread throughout

3201-705: The Columbian exchange , it has become a staple food in many parts of the world, with the total production of maize surpassing that of wheat and rice . Much maize is used for animal feed , whether as grain or as the whole plant, which can either be baled or made into the more palatable silage . Sugar-rich varieties called sweet corn are grown for human consumption, while field corn varieties are used for animal feed, for uses such as cornmeal or masa , corn starch , corn syrup , pressing into corn oil , alcoholic beverages like bourbon whiskey , and as chemical feedstocks including ethanol and other biofuels . Maize

3298-544: The Eastern Seaboard of the United States, the Canadian Maritimes , and most of Newfoundland and Labrador . Nearly all of South America east of the Andes also drains to the Atlantic, as does most of Western and Central Europe and the greatest portion of western Sub-Saharan Africa , as well as Western Sahara and part of Morocco . The two major mediterranean seas of the world also flow to

3395-735: The Mississippi (3.22 million km ), and the Río de la Plata (3.17 million km ). The three rivers that drain the most water, from most to least, are the Amazon, Ganges , and Congo rivers. Endorheic basin are inland basins that do not drain to an ocean. Endorheic basins cover around 18% of the Earth's land. Some endorheic basins drain to an Endorheic lake or Inland sea . Many of these lakes are ephemeral or vary dramatically in size depending on climate and inflow. If water evaporates or infiltrates into

3492-809: The Nile River ), Southern , Central, and Eastern Europe , Turkey , and the coastal areas of Israel , Lebanon , and Syria . The Arctic Ocean drains most of Western Canada and Northern Canada east of the Continental Divide , northern Alaska and parts of North Dakota , South Dakota , Minnesota , and Montana in the United States, the north shore of the Scandinavian peninsula in Europe, central and northern Russia, and parts of Kazakhstan and Mongolia in Asia , which totals to about 17% of

3589-607: The 1983 Nobel Prize in Physiology or Medicine . Maize remains an important model organism for genetics and developmental biology . The MADS-box motif is involved in the development of maize flowers. The Maize Genetics and Genomics Database is funded by the US Department of Agriculture to support maize research. The International Maize and Wheat Improvement Center maintains a large collection of maize accessions tested and cataloged for insect resistance. In 2005,

3686-662: The Americas. Maize pollen dated to 7,300 years ago from San Andres, Tabasco has been found on the Caribbean coast. 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 , are roughly 6,250 years old; the oldest ears from caves near Tehuacan , Puebla, are 5,450 years old. Around 4,500 years ago, maize began to spread to

3783-789: The Andes. The Indian Ocean 's drainage basin also comprises about 13% of Earth's land. It drains the eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf , the Indian subcontinent , Burma, and most parts of Australia . The five largest river basins (by area), from largest to smallest, are those of the Amazon (7 million km ), the Congo (4 million km ), the Nile (3.4 million km ),

3880-669: The Atlantic. The Caribbean Sea and Gulf of Mexico basin includes most of the U.S. interior between the Appalachian and Rocky Mountains , a small part of the Canadian provinces of Alberta and Saskatchewan , eastern Central America , the islands of the Caribbean and the Gulf, and a small part of northern South America. The Mediterranean Sea basin, with the Black Sea , includes much of North Africa , east-central Africa (through

3977-479: The B-vitamin niacin , the lack of which caused pellagra . 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 contributed to its demise. Pellagra still exists in food-poor areas and refugee camps where people survive on donated maize. The name maize derives from

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4074-709: The Maize Association of Australia, the National Maize Association of Nigeria, the National Maize Association of Ghana, the Maize Trust of South Africa, and the Zimbabwe Seed Maize Association. Maize is a tall annual grass with a single stem, ranging in height from 1.2 m (4 ft) to 4 m (13 ft). The long narrow leaves arise from the nodes or joints, alternately on opposite sides on

4171-669: The Maryland Archaeological Conservation Lab, "Monongahela ceramics are a complex series that begin with an early grit or limestone tempered group and end with a very anomalous collection of types found in southwestern Pennsylvania during the post-Contact period." According to the collaborative research of 2009 of William C. Johnson (Society for Pennsylvania Archaeology) and D. Scott Speedy (Grave Creek Mound Archaeology Complex Research Facility in West Virginia), Monongahela tradition women favored

4268-601: The Monongahela were killed by or assimilated into either the Iroquois or the Algonquian -speaking Lenape tribes during warfare, as the more powerful tribes competed to control area hunting grounds for the fur trade . Still others claim that two severe droughts , one from 1587 to 1589 and another from 1607 to 1612, drove habitable area. An internal temporal subdivision of the Monongahela culture, based on ceramic decorative attributes. The Monongahela culture extended in

4365-633: The Monongahela's greater Woodland heritage was the continued use of small stone mounds in the Monongahela drainage area, well into the Late Prehistoric." Child burials were sometimes inside the village and sometimes under the house. This contrasted with Andaste (Susquehannock) burials from 1450/1550, which were outside the palisaded village, as found east of the Allegheny Mountains . By 1450, petal-shaped attachments to their houses became common. These were used for storage or perhaps

4462-532: The Monongahela. About the year of 1635, it appears that a group of refugees from the Monongahela culture resettled in south-central Virginia at Halifax County . They were likely absorbed by a Siouan -speaking tribe of the area, but historians do not know for sure. There were also Algonquian and Iroquoian -speaking tribes nearby. Maize Maize / m eɪ z / ( Zea mays ), also known as corn in North American English ,

4559-589: The Native Americans did not have immunity , the new diseases resulted in high fatalities in widespread areas. The Monongahela culture was progressively disappearing before the time the Iroquois League invaded the Allegheny Plateau through to the Lake Erie region in an effort to control new hunting grounds for the lucrative fur trade . The powerful Iroquois likely conquered or drove out

4656-586: The Spanish form maíz of the Taíno mahis . The Swedish botanist Carl Linnaeus used the common name maize as the species epithet in Zea mays . The name 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. Most countries primarily use

4753-562: The US National Science Foundation , Department of Agriculture, and the Department of Energy formed a consortium to sequence the maize genome . The resulting DNA sequence data was deposited immediately into GenBank , a public repository for genome-sequence data. Sequencing of the maize genome was completed in 2008. In 2009, the consortium published results of its sequencing effort. The genome, 85% of which

4850-534: The US from each of two major insect pests , namely the European corn borer or ECB ( Ostrinia nubilalis ) and corn rootworms ( Diabrotica spp ) western corn rootworm , northern corn rootworm , and southern corn rootworm . Another serious pest is the fall armyworm ( Spodoptera frugiperda ). The maize weevil ( Sitophilus zeamais ) is a serious pest of stored grain. The Northern armyworm, Oriental armyworm or Rice ear-cutting caterpillar ( Mythimna separata )

4947-575: The US, interstate compacts ) or other political entities in a particular drainage basin to manage the body or bodies of water into which it drains. Examples of such interstate compacts are the Great Lakes Commission and the Tahoe Regional Planning Agency . In hydrology , the drainage basin is a logical unit of focus for studying the movement of water within the hydrological cycle . The process of finding

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5044-542: The area of the upper Ohio River system that includes the Monongahela , Youghiogheny and Casselman tributary rivers. Their region was of western Pennsylvania and the adjoining areas of eastern Ohio , West Virginia , and western Maryland . Nearly four hundred archeological sites have been recorded. The culture was contemporaneous to the bordering Fort Ancient culture in the Ohio Valley . The Monongahela

5141-406: The basin, it can form tributaries that change the structure of the land. There are three different main types, which are affected by the rocks and ground underneath. Rock that is quick to erode forms dendritic patterns, and these are seen most often. The two other types of patterns that form are trellis patterns and rectangular patterns. Rain gauge data is used to measure total precipitation over

5238-418: 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. Sweet corn, harvested earlier than maize grown for grain, grows to maturity in a period of from 60 to 100 days according to variety. An extended sweet corn harvest, picked at

5335-613: The body of Christ. 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. By the 17th century, it was a common peasant food in Southern Europe. By the 18th century, it was the chief food of the southern French and Italian peasantry, especially as polenta in Italy. When maize

5432-577: The cob on their own, while those of domesticated maize do not. All maize arose from a single domestication in southern Mexico about 9,000 years ago. The oldest surviving maize types are those of the Mexican highlands. Maize spread from this region to the lowlands and over the Americas along two major paths. The centre of domestication was most likely the Balsas River valley of south-central Mexico. Maize reached highland Ecuador at least 8000 years ago. It reached lower Central America by 7600 years ago, and

5529-450: The culture began failing due to poor health conditions. In addition, some scholars believe that two severe droughts , one from 1587 to 1589 and another from 1607 to 1612, drove the bearer of the Monongahela culture from the region in search of a more habitable area. Because of trade with other groups, the Monongahela could have contracted infectious diseases from coastal peoples, who were directly exposed by their contact with Europeans. As

5626-430: The discharge of water from a basin may be made by a stream gauge located at the basin's outlet. Depending on the conditions of the drainage basin, as rainfall occurs some of it seeps directly into the ground. This water will either remain underground, slowly making its way downhill and eventually reaching the basin, or it will permeate deeper into the soil and consolidate into groundwater aquifers. As water flows through

5723-441: The drainage area is dependent on the soil type. Certain soil types such as sandy soils are very free-draining, and rainfall on sandy soil is likely to be absorbed by the ground. However, soils containing clay can be almost impermeable and therefore rainfall on clay soils will run off and contribute to flood volumes. After prolonged rainfall even free-draining soils can become saturated , meaning that any further rainfall will reach

5820-697: The drainage basin to the mouth, and may accumulate there, disturbing the natural mineral balance. This can cause eutrophication where plant growth is accelerated by the additional material. Because drainage basins are coherent entities in a hydrological sense, it has become common to manage water resources on the basis of individual basins. In the U.S. state of Minnesota , governmental entities that perform this function are called " watershed districts ". In New Zealand, they are called catchment boards. Comparable community groups based in Ontario, Canada, are called conservation authorities . In North America, this function

5917-425: The earliest and most successful, developing Reid's Yellow Dent in the 1860s. These early efforts were based on mass selection (a row of plants is grown from seeds of one parent), and the choosing of plants after pollination (which means that only the female parents are known). Later breeding efforts included ear to row selection (C. G. Hopkins c. 1896), hybrids made from selected inbred lines (G. H. Shull, 1909), and

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6014-413: The entire ear is harvested, which 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 , sufficient for some livestock feeding uses. 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 harvester and store it in bins . The combine with

6111-722: The expansion of the Inca Empire , maize was traded and transported as far south as 40° S in Melinquina, Lácar Department , Argentina, probably brought across the Andes from Chile. After the arrival of Europeans in 1492, Spanish settlers consumed maize, and explorers and traders carried it back to Europe . Spanish settlers much preferred wheat bread to maize. Maize flour could not be substituted for wheat for communion bread, since in Christian belief at that time only wheat could undergo transubstantiation and be transformed into

6208-435: The ground and along rivers it can pick up nutrients , sediment , and pollutants . With the water, they are transported towards the outlet of the basin, and can affect the ecological processes along the way as well as in the receiving water body . Modern use of artificial fertilizers , containing nitrogen (as nitrates ), phosphorus , and potassium , has affected the mouths of drainage basins. The minerals are carried by

6305-781: The ground at its terminus, the area can go by several names, such playa, salt flat, dry lake , or alkali sink . The largest endorheic basins are in Central Asia , including the Caspian Sea , the Aral Sea , and numerous smaller lakes. Other endorheic regions include the Great Basin in the United States, much of the Sahara Desert , the drainage basin of the Okavango River ( Kalahari Basin ), highlands near

6402-532: 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. 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

6499-432: The history of the word corn in North America that "[t]o say the word corn is to plunge into the tragi-farcical mistranslations of language and history". Similar to the British usage, 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; Fussell comments that "they meant not

6596-419: The machinery. The combine separates the husk and the cob, keeping only the kernels. Drying is vital to prevent or at least reduce damage by mould fungi, which contaminate the grain with mycotoxins . Aspergillus and Fusarium spp. are the most common mycotoxin sources, and accordingly important in agriculture. If the moisture content of the harvested grain is too high, grain dryers are used to reduce

6693-512: The mid-Atlantic coastal people with whom they also traded. As evidence of that trade, sea shells from the mid-Atlantic have been found in some Monongahela sites. This late prehistoric culture peaked about AD 1300. The colder weather of the Little Ice Age may have caused inter-group battling over food and farmland, according to some scholars. The crops did not prosper as well during this colder period, causing food shortages for populations that had grown after their introduction. Some studies show that

6790-413: The milk stage, can be arranged either by planting a selection of varieties which ripen earlier and later, or by planting different areas at fortnightly intervals. 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 can be harvested and stored in the husk leaves if kept dry. Before World War II , most maize in North America

6887-427: 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. Maize is widely cultivated throughout the world, and a greater weight of maize is produced each year than any other grain. In 2020, total world production was 1.16 billion tonnes , led by the United States with 31.0% of

6984-501: The need for cropland, pesticides, water and fertilizer. 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. Certain varieties of maize have been bred to produce many ears; these are

7081-400: The new crop. 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. 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

7178-465: The north. In the United States, maize was first cultivated at several sites in New Mexico and Arizona about 4,100 years ago. 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

7275-760: The presence of Starlink genetically modified corn, which had been approved only for animal consumption. The maize genus Zea is relatively closely related to sorghum , both being in the PACMAD clade of Old World grasses, and much more distantly to rice and wheat , which are in the other major group of grasses, the BOP clade . It is closely related to Tripsacum , gamagrass. various grasses e.g. fescue , ryegrass Hordeum (barley) Triticum (wheat) Oryza (rice) Pennisetum (fountaingrasses) Sorghum (sorghum) Tripsacum (gamagrass) Zea mays (maize) other Zea species ( teosintes ) Maize

7372-498: The production of final Z-twist cordage production. On the upper Ohio River drainage basin subareas, some pottery apparently represents the incorporation of local Late Woodland groups with their own distinctive cordage-manufacturing traditions. As Johnson and Speedy say in their abstract, "In the absence of elaborately decorated ceramics, variations in the relative frequency of the predominant cordage twist direction peculiar to some subareas also suggest that twist direction may function as

7469-418: The rainfall on the area of land included in its polygon. These polygons are made by drawing lines between gauges, then making perpendicular bisectors of those lines form the polygons. The isohyetal method involves contours of equal precipitation are drawn over the gauges on a map. Calculating the area between these curves and adding up the volume of water is time-consuming. Isochrone maps can be used to show

7566-631: The responsibility of the countries sharing it. Nile Basin Initiative , OMVS for Senegal River , Mekong River Commission are a few examples of arrangements involving management of shared river basins. Management of shared drainage basins is also seen as a way to build lasting peaceful relationships among countries. The catchment is the most significant factor determining the amount or likelihood of flooding . Catchment factors are: topography , shape, size, soil type, and land use (paved or roofed areas). Catchment topography and shape determine

7663-461: The river rather than being absorbed by the ground. If the surface is impermeable the precipitation will create surface run-off which will lead to higher risk of flooding; if the ground is permeable, the precipitation will infiltrate the soil. Land use can contribute to the volume of water reaching the river, in a similar way to clay soils. For example, rainfall on roofs, pavements , and roads will be collected by rivers with almost no absorption into

7760-613: The site. In 2002 the site was endangered with destruction by commercial development. The majority of the 18 known sites within the Osage USGS Quadrangle and the Blacksville USGS Quadrangle on the environs of the Pennsylvania and West Virginia border are of the Monongahela Culture. The Worley village Complex (46Mg23) dates to about AD 900. It is located within the Blacksville USGS Quadrangle, as

7857-491: The source of the " baby corn " used as a vegetable in Asian cuisine . A fast-flowering variety named mini-maize was developed to aid scientific research, as multiple generations can be obtained in a single year. One strain called olotón has evolved a symbiotic relationship with nitrogen-fixing microbes, which provides the plant with 29%–82% of its nitrogen. The International Maize and Wheat Improvement Center (CIMMYT) operates

7954-418: The speed with which the runoff reaches a river. A long thin catchment will take longer to drain than a circular catchment. Size will help determine the amount of water reaching the river, as the larger the catchment the greater the potential for flooding. It is also determined on the basis of length and width of the drainage basin. Soil type will help determine how much water reaches the river. The runoff from

8051-415: The stalk. Maize is monoecious , with separate male and female flowers on the same plant. At the top of the stem is the tassel, an inflorescence of male flowers; their anthers release pollen, which is dispersed by wind . Like other pollen, it is an allergen , but most of it falls within a few meters of the tassel and the risk is largely restricted to farm workers. The female inflorescence, some way down

8148-425: The stem from the tassel, is first seen as a silk, a bundle of soft tubular hairs , one for the carpel in each female flower, which develops into a kernel (often called a seed. Botanically, as in all grasses, it is a fruit, fused with the seed coat to form a caryopsis ) when it is pollinated. A whole female inflorescence develops into an ear or corncob , enveloped by multiple leafy layers or husks. The ear leaf

8245-608: The term maize , and the name corn is used mainly in the United States and a handful of other English-speaking countries. In countries that primarily use the term maize , the word corn may denote any cereal crop, varying geographically with the local staple , such as wheat in England and oats in Scotland or Ireland. The usage of corn for maize started as a shortening of " Indian corn " in 18th-century North America. The historian of food Betty Fussell writes in an article on

8342-415: The time taken for rain to reach the river, while catchment size, soil type, and development determine the amount of water to reach the river. Generally, topography plays a big part in how fast runoff will reach a river. Rain that falls in steep mountainous areas will reach the primary river in the drainage basin faster than flat or lightly sloping areas (e.g., > 1% gradient). Shape will contribute to

8439-477: The time taken for runoff water within a drainage basin to reach a lake, reservoir or outlet, assuming constant and uniform effective rainfall. Drainage basins are the principal hydrologic unit considered in fluvial geomorphology . A drainage basin is the source for water and sediment that moves from higher elevation through the river system to lower elevations as they reshape the channel forms. Drainage basins are important in ecology . As water flows over

8536-472: The total (table). China produced 22.4% of the global total. Many pests can affect maize growth and development, including invertebrates, weeds, and pathogens. Maize is susceptible to a large number of fungal, bacterial, and viral plant diseases . Those of economic importance include diseases of the leaf, smuts such as corn smut , ear rots and stalk rots. Northern corn leaf blight damages maize throughout its range, whereas banded leaf and sheath blight

8633-500: The two is largely controlled by differences in just two genes, called grassy tillers-1 ( gt1 , A0A317YEZ1 ) and teosinte branched-1 ( tb1 , Q93WI2 ). 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 has been refuted by modern genetic testing . In 2004, John Doebley identified Balsas teosinte, Zea mays subsp. parviglumis , native to

8730-589: The valleys of the Colombian Andes between 7000 and 6000 years ago. The earliest maize plants grew a single, small ear per plant. The Olmec and Maya cultivated maize in numerous varieties throughout Mesoamerica ; they cooked, ground and processed it through nixtamalization . By 3000 years ago, maize was central to Olmec culture, including their calendar, language, and myths. The Mapuche people of south-central Chile cultivated maize along with quinoa and potatoes in pre-Hispanic times. Before

8827-430: The villages had elevated observation platforms. Charnel houses have been found in the larger villages. Black bear masks have been found in some graves, showing a possible indication of a rank. Of the average adult burials, it is not clearly understood where they might have been buried. To distinguish the characteristics between Fort Ancient and interior Monongahelan of West Virginia, Dr. McMichael writes, "A reflection of

8924-530: The west and south, they depended on maize as the major staple of their diet. The Monongahela men hunted animals including deer and turtles, and caught fish and shell fish. They made advances in the cultivation of tobacco and hemp braid crops, and traded these with the East Coast agriculturists. In 1599 - 1600 the English geographer and propagandist Richard Hakluyt reported on Native American foods of

9021-789: The world's land. Just over 13% of the land in the world drains to the Pacific Ocean . Its basin includes much of China, eastern and southeastern Russia, Japan, the Korean Peninsula , most of Indochina, Indonesia and Malaysia, the Philippines, all of the Pacific Islands , the northeast coast of Australia , and Canada and the United States west of the Continental Divide (including most of Alaska), as well as western Central America and South America west of

9118-461: Was a symptom of intergroup warfare. The Fort Hill Site (46MG12) in Morgantown, West Virginia is a nearly 5-acre (20,000 m) archeological site that includes what appears to be a Monongahela village. The site has good preservation. A human burial, animal bones, bone beads, a marginella -shell bead, shell-tempered pottery and triangular arrow points have been recovered during excavations at

9215-458: 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. The latter produce sheaves that can be shocked . By hand or mechanical picker,

9312-425: Was introduced into Western farming systems, it was welcomed for its productivity. However, a widespread problem of malnutrition soon arose wherever it had become a staple food . Indigenous Americans had learned to soak maize in alkali -water — made with ashes and lime — since at least 1200–1500 BC, creating the process of nixtamalization. They did this to liberate the corn hulls, but coincidentally it also liberated

9409-466: Was one of the 26 genetically engineered food crops grown commercially in 2016. The vast majority of this is Bt maize . Genetically modified maize has been grown since 1997 in the United States and Canada; by 2016, 92% of the US maize crop was genetically modified. As of 2011, herbicide-tolerant maize and insect-resistant maize varieties were each grown in over 20 countries. In September 2000, up to $ 50 million worth of food products were recalled due to

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