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Rice

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In horticulture , the term ( per- + -ennial , "through the year") is used to differentiate a plant from shorter-lived annuals and biennials . It has thus been defined as a plant that lives more than two years. The term is also loosely used to distinguish plants with little or no woody growth (secondary growth in girth) from trees and shrubs, which are also technically perennials . Notably, it is estimated that 94% of plant species fall under the category of perennials, underscoring the prevalence of plants with lifespans exceeding two years in the botanical world.

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91-750: Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population , particularly in Asia and Africa . Rice is the seed of the grass species Oryza sativa (Asian rice)—or, much less commonly, Oryza glaberrima (African rice). Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated in Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2021, 787 million tons were produced, placing it fourth after sugarcane , maize , and wheat . Only some 8% of rice

182-443: A century plant can live for 80 years and grow 30 meters tall before flowering and dying. However, most perennials are polycarpic (or iteroparous ), flowering over many seasons in their lifetime. Perennials invest more resources than annuals into roots, crowns, and other structures that allow them to live from one year to the next. They often have a competitive advantage because they can commence their growth and leaf out earlier in

273-657: A grain elevator or silo , to be sold later. Grain stores need to be constructed to protect the grain from damage by pests such as seed-eating birds and rodents . When the cereal is ready to be distributed, it is sold to a manufacturing facility that first removes the outer layers of the grain for subsequent milling for flour or other processing steps, to produce foods such as flour, oatmeal , or pearl barley . In developing countries, processing may be traditional, in artisanal workshops, as with tortilla production in Central America. Most cereals can be processed in

364-940: A photolyase and the other, a protein involved in nucleotide excision repair ). Perennials that are cultivated include: woody plants like fruit trees grown for their edible fruits; shrubs and trees grown as landscaping ornamentals ; herbaceous food crops like asparagus , rhubarb , strawberries ; and subtropical plants not hardy in colder areas such as tomatoes , eggplant , and coleus (which are treated as annuals in colder areas). Perennials also include plants grown for their flowering and other ornamental value including bulbs (like tulips, narcissus, and gladiolus); lawn grass, and other groundcovers , (such as periwinkle and Dichondra ). Each type of plant must be separated differently; for example, plants with fibrous root systems like daylilies, Siberian iris, or grasses can be pried apart with two garden forks inserted back to back, or cut by knives. However, plants such as bearded irises have

455-416: A sustainable way. Many varieties of rice have been bred to improve crop quality and productivity. Biotechnology has created Green Revolution rice able to produce high yields when supplied with nitrogen fertiliser and managed intensively. Other products are rice able to express human proteins for medicinal use; flood-tolerant or deepwater rice ; and drought-tolerant and salt-tolerant varieties. Rice

546-444: A balanced diet. Many legumes, however, are deficient in the essential amino acid methionine , which grains contain. Thus, a combination of legumes with grains forms a well-balanced diet for vegetarians. Such combinations include dal (lentils) with rice by South Indians and Bengalis , beans with maize tortillas , tofu with rice, and peanut butter with wholegrain wheat bread (as sandwiches) in several other cultures, including

637-402: A branched inflorescence which arises from the last internode on the stem. There can be up to 350 spikelets in a panicle, each containing male and female flower parts ( anthers and ovule ). A fertilised ovule develops into the edible grain or caryopsis . Rice is a cereal belonging to the family Poaceae . As a tropical crop, it can be grown during the two distinct seasons (dry and wet) of

728-401: A food trade imbalance and thus food security . Speculation , as well as other compounding production and supply factors leading up to the 2007–2008 financial crises , created rapid inflation of grain prices during the 2007–2008 world food price crisis . Other disruptions, such as climate change or war related changes to supply or transportation can create further food insecurity; for example

819-410: A role in various religions and traditions, such as in weddings . The rice plant can grow to over 1 m (3 ft) tall; if in deep water, it can reach a length of 5 m (16 ft). A single plant may have several leafy stems or tillers . The upright stem is jointed with nodes along its length; a long slender leaf arises from each node. The self-fertile flowers are produced in a panicle ,

910-408: A role. Among the best-known cereals are maize, rice , wheat, barley, sorghum , millet , oat, rye and triticale . Some other grains are colloquially called cereals, even though they are not grasses; these pseudocereals include buckwheat , quinoa , and amaranth . All cereal crops are cultivated in a similar way. Most are annual , so after sowing they are harvested just once. An exception

1001-470: A root system of rhizomes; these root systems should be planted with the top of the rhizome just above ground level, with leaves from the following year showing. The point of dividing perennials is to increase the amount of a single breed of plant in your garden. In the United States more than 900 million dollars worth of potted herbaceous perennial plants were sold in 2019. Although most of humanity

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1092-510: A single domestication event for O. sativa . Both indica and japonica forms of Asian rice sprang from a single domestication event in China from the wild rice Oryza rufipogon . Despite this evidence, it appears that indica rice arose when japonica arrived in India about 4,500 years ago and hybridised with another rice, whether an undomesticated proto- indica or wild O. nivara . Rice

1183-536: A sugar . In the 20th century, industrial processes developed around chemically altering the grain, to be used for other processes. In particular, maize can be altered to produce food additives, such as corn starch and high-fructose corn syrup . Cereal production has a substantial impact on the environment. Tillage can lead to soil erosion and increased runoff. Irrigation consumes large quantities of water; its extraction from lakes, rivers, or aquifers may have multiple environmental effects , such as lowering

1274-500: A variety of ways. Rice processing , for instance, can create whole-grain or polished rice, or rice flour. Removal of the germ increases the longevity of grain in storage. Some grains can be malted , a process of activating enzymes in the seed to cause sprouting that turns the complex starches into sugars before drying. These sugars can be extracted for industrial uses and further processing, such as for making industrial alcohol , beer , whisky , or rice wine , or sold directly as

1365-479: A very few (e.g. Zostera ) occurring in shallow sea water. Herbaceous perennial plants are particularly dominant in conditions too fire-prone for trees and shrubs, e.g., most plants on prairies and steppes are perennials; they are also dominant on tundra too cold for tree growth. Nearly all forest plants are perennials, including trees and shrubs. Perennial plants are usually better long-term competitors, especially under stable, resource-poor conditions. This

1456-437: A wide variety of pests including insects, nematodes, rodents such as rats, snails, and birds. Major rice insect pests include armyworms, rice bugs , black bugs , cutworms, field crickets, grasshoppers, leafhoppers, mealybugs, and planthoppers. High rates of nitrogen fertiliser application may worsen aphid outbreaks. Weather conditions can contribute to pest outbreaks: rice gall midge outbreaks are worsened by high rainfall in

1547-434: Is rainfed like wheat or maize. Across Asia, unmilled rice or "paddy" (Indonesian and Malay padi ), was traditionally the product of smallholder agriculture, with manual harvesting . Larger farms make use of machines such as combine harvesters to reduce the input of labour. The grain is ready to harvest when the moisture content is 20–25%. Harvesting involves reaping , stacking the cut stalks, threshing to separate

1638-676: Is 69% water, 29% carbohydrates , 2% protein , and contains negligible fat (table). In a reference serving of 100 grams (3.5 oz), cooked white rice provides 130 calories of food energy , and contains moderate levels of manganese (18% DV), with no other micronutrients in significant content (all less than 10% of the Daily Value ). In 2018, the World Health Organization strongly recommended fortifying rice with iron , and conditionally recommended fortifying it with vitamin A and with folic acid . Golden rice

1729-625: Is a major food staple in Asia, Latin America, and some parts of Africa, feeding over half the world's population. However, a substantial part of the crop can be lost post-harvest through inefficient transportation, storage, and milling. A quarter of the crop in Nigeria is lost after harvest. Storage losses include damage by mould fungi if the rice is not dried sufficiently. In China, losses in modern metal silos were just 0.2%, compared to 7–13% when rice

1820-501: Is a variety produced through genetic engineering to synthesize beta-carotene , a precursor of vitamin A, in the endosperm of the rice grain. It is intended to be grown and eaten in parts of the world where Vitamin A deficiency is prevalent. Golden rice has been opposed by activists, such as in the Philippines . In 2016 more than 100 Nobel laureates encouraged the use of genetically modified organisms , such as golden rice, for

1911-577: Is based on four principles: biodiversity, host plant resistance, landscape ecology, and hierarchies in a landscape—from biological to social. Farmers' pesticide applications are often unnecessary. Pesticides may actually induce resurgence of populations of rice pests such as the brown planthopper , both by destroying beneficial insects and by enhancing the pest's reproduction. The International Rice Research Institute (IRRI) demonstrated in 1993 that an 87.5% reduction in pesticide use can lead to an overall drop in pest numbers. Farmers in China, Indonesia and

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2002-783: Is due to the development of larger root systems which can access water and soil nutrients deeper in the soil and to earlier emergence in the spring. Annual plants have an advantage in disturbed environments because of their faster growth and reproduction rates. Each section contains a short list of species related to that topic, these are an example as the true lists would fill several books. Perennials grown for their decorative flowers include very many species and types. Some examples include: The majority of fruit bearing plants are perennial even in temperate climates. Examples include: Many herbs are perennial, including these examples: Many vegetable plants can grow as perennials in tropical climates, but die in cold weather. Examples of some of

2093-483: Is fed by the re-sowing of the seeds of annual grain crops, (either naturally or by the manual efforts of humans), perennial crops provide numerous benefits. Perennial plants often have deep, extensive root systems which can hold soil to prevent erosion , capture dissolved nitrogen before it can contaminate ground and surface water, and out-compete weeds (reducing the need for herbicides ). These potential benefits of perennials have resulted in new attempts to increase

2184-505: Is from Asia. The average world yield for rice was 4.7 metric tons per hectare (2.1 short tons per acre), in 2022. Yuan Longping of China's National Hybrid Rice Research and Development Center set a world record for rice yield in 1999 at 17.1 metric tons per hectare (7.6 short tons per acre) on a demonstration plot. This employed specially developed hybrid rice and the System of Rice Intensification (SRI), an innovation in rice farming. Rice

2275-614: Is no frost. Most cereals are planted in tilled soils , which reduces weeds and breaks up the surface of a field. Most cereals need regular water in the early part of their life cycle. Rice is commonly grown in flooded fields, though some strains are grown on dry land. Other warm climate cereals, such as sorghum, are adapted to arid conditions. Cool-season cereals are grown mainly in temperate zones. These cereals often have both winter varieties for autumn sowing, winter dormancy, and early summer harvesting, and spring varieties planted in spring and harvested in late summer. Winter varieties have

2366-614: Is not required. Rice can be grown as a ratoon crop; and other researchers are exploring perennial cool-season cereals, such as kernza , being developed in the US. Fertilizer and pesticide usage may be reduced in some polycultures , growing several crops in a single field at the same time. Fossil fuel-based nitrogen fertilizer usage can be reduced by intercropping cereals with legumes which fix nitrogen . Greenhouse gas emissions may be cut further by more efficient irrigation or by water harvesting methods like contour trenching that reduce

2457-427: Is often used to make injera . It can be eaten as a warm breakfast cereal like farina with a chocolate or nutty flavor. The table shows the annual production of cereals in 1961, 1980, 2000, 2010, and 2019/2020. (millions of metric tons) Cereals are the most traded commodities by quantity in 2021, with wheat, maize, and rice the main cereals involved. The Americas and Europe are the largest exporters, and Asia

2548-510: Is rice, which although usually treated as an annual can survive as a perennial , producing a ratoon crop. Cereals adapted to a temperate climate , such as barley , oats , rye , spelt , triticale , and wheat , are called cool-season cereals. Those preferring a tropical climate , such as millet and sorghum , are called warm-season cereals. Cool-season cereals, especially rye, followed by barley, are hardy; they grow best in fairly cool weather, and stop growing, depending on variety, when

2639-811: Is sister to the bamboos, Bambusoideae , and the cereal subfamily Pooideae . The rice genus Oryza is one of eleven in the Oryzeae; it is sister to the Phyllorachideae . The edible rice species O. sativa and O. glaberrima are among some 300 species or subspecies in the genus. other grasses (inc. the C4 grasses , maize , sorghum ) Streptogyneae Ehrharteae Phyllorachideae Wild rices inc. Zizania other rice species and subspecies O. sativa (Asian rice) O. glaberrima (African rice) Bambusoideae (bamboos) Pooideae (grasses and cereals inc. wheat , barley ) Oryza sativa rice

2730-565: Is sometimes grown as a perennial . Winter varieties are hardy enough to be planted in the autumn, becoming dormant in the winter, and harvested in spring or early summer; spring varieties are planted in spring and harvested in late summer. The term cereal is derived from the name of the Roman goddess of grain crops and fertility, Ceres . Cereals were domesticated in the Neolithic , some 8,000 years ago. Wheat and barley were domesticated in

2821-694: Is stickier, and is used for sweet dishes, and in Italy for risotto ; and sticky short-grain rice is used in Japanese sushi as it keeps its shape when cooked. White rice when cooked contains 29% carbohydrate and 2% protein, with some manganese . Golden rice is a variety produced by genetic engineering to contain vitamin A . Production of rice is estimated to have caused over 1% of global greenhouse gas emissions in 2022. Predictions of how rice yields will be affected by climate change vary across geographies and socioeconomic contexts. In human culture, rice plays

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2912-436: Is subjected to a steaming process before it is milled. This makes the grain harder, and moves some of the grain's vitamins and minerals into the white part of the rice so these are retained after milling. Rice does not contain gluten , so is suitable for people on a gluten-free diet . Rice is a good source of protein and a staple food in many parts of the world, but it is not a complete protein as it does not contain all of

3003-475: Is the largest importer. The largest exporter of maize is the US, while India is the largest exporter of rice. China is the largest importer of maize and of rice. Many other countries trade cereals, both as exporters and as importers. Cereals are traded as futures on world commodity markets , helping to mitigate the risks of changes in price for example, if harvests fail. Perennial Perennials (especially small flowering plants ) that grow and bloom over

3094-461: Is the main ingredient of bread and pasta . Maize flour has been important in Mesoamerica since ancient times, with foods such as Mexican tortillas and tamales . Rye flour is a constituent of bread in central and northern Europe, while rice flour is common in Asia. A cereal grain consists of starchy endosperm , germ , and bran . Wholemeal flour contains all of these; white flour

3185-404: Is to flood the field to a depth of 5 cm (2 in), then to let the water level drop to 15 cm (6 in) below surface level, as measured by looking into a perforated field water tube sunk into the soil, and then repeating the cycle. Deepwater rice varieties tolerate flooding to a depth of over 50 centimetres for at least a month. Upland rice is grown without flooding, in hilly or mountainous regions; it

3276-429: Is too cold or dry. In many parts of the world, seasonality is expressed as wet and dry periods rather than warm and cold periods, and deciduous perennials lose their leaves in the dry season. Some perennial plants are protected from wildfires because they have underground roots that produce adventitious shoots, bulbs, crowns , or stems ; other perennials like trees and shrubs may have thick cork layers that protect

3367-509: Is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects , rodents , and birds , as well as by weeds , and by diseases such as rice blast . Traditional rice polycultures such as rice-duck farming , and modern integrated pest management seek to control damage from pests in

3458-471: Is used as a model organism in biology. Dry rice grain is milled to remove the outer layers; depending on how much is removed, products range from brown rice to rice with germ and white rice. Some is parboiled to make it easy to cook. Rice contains no gluten ; it provides protein but not all the essential amino acids needed for good health. Rice of different types is eaten around the world. Long-grain rice tends to stay intact on cooking; medium-grain rice

3549-402: Is without some or all of the germ or bran. Because cereals have a high starch content, they are often used to make industrial alcohol and alcoholic drinks by fermentation . For instance, beer is produced by brewing and fermenting starch , mainly from cereal grains—most commonly malted barley. Rice wines such as Japanese sake are brewed in Asia; a fermented rice and honey wine

3640-459: The Puccinia spp.) and powdery mildews . Fusarium head blight, caused by Fusarium graminearum , is a significant limitation on a wide variety of cereals. Other pressures include pest insects and wildlife like rodents and deer. In conventional agriculture, some farmers will apply fungicides or pesticides Annual cereals die when they have come to seed, and dry up. Harvesting begins once

3731-473: The "organic" movements of the early 21st century, but there is a tradeoff in yield-per-plant, putting pressure on resource-poor areas as food crops are replaced with cash crops . Cereals are grasses, in the Poaceae family, that produce edible grains . A cereal grain is botanically a caryopsis , a fruit where the seed coat is fused with the pericarp . Grasses have stems that are hollow except at

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3822-747: The Fertile Crescent ; rice was domesticated in East Asia, and sorghum and millet were domesticated in West Africa. Maize was domesticated by Indigenous peoples of the Americas in southern Mexico about 9,000 years ago. In the 20th century, cereal productivity was greatly increased by the Green Revolution . This increase in production has accompanied a growing international trade , with some countries producing large portions of

3913-840: The Green Revolution , a technological change funded by development organizations. The strategies developed by the Green Revolution, including mechanized tilling, monoculture , nitrogen fertilizers, and breeding of new strains of seeds. These innovations focused on fending off starvation and increasing yield-per-plant, and were very successful in raising overall yields of cereal grains, but paid less attention to nutritional quality. These modern high-yield cereal crops tend to have low-quality proteins , with essential amino acid deficiencies, are high in carbohydrates , and lack balanced essential fatty acids , vitamins , minerals and other quality factors. So-called ancient grains and heirloom varieties have seen an increase in popularity with

4004-492: The Russian invasion of Ukraine in 2022 disrupted Ukrainian and Russian wheat supplies causing a global food price crisis in 2022 that affected countries heavily dependent on wheat flour. Cereals are the world's largest crops by tonnage of grain produced. Three cereals, maize, wheat, and rice, together accounted for 89% of all cereal production worldwide in 2012, and 43% of the global supply of food energy in 2009, while

4095-475: The astronomical symbol for the planet Jupiter . Perennial plants can be short-lived (only a few years) or long-lived. They include a wide assortment of plant groups from non-flowering plants like ferns and liverworts to highly diverse flowering plants like orchids , grasses , and woody plants . Plants that flower and fruit only once and then die are termed monocarpic or semelparous ; these species may live for many years before they flower. For example,

4186-438: The essential amino acids in sufficient amounts for good health. World trade figures are much smaller than those for production, as less than 8% of rice produced is traded internationally. China, an exporter of rice in the early 2000s, had become the world's largest importer of rice by 2013. Developing countries are the main players in the world rice trade; by 2012, India was the largest exporter of rice, with Thailand and Vietnam

4277-400: The nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath. The leaf grows from the base of the blade, an adaptation that protects the growing meristem from grazing animals. The flowers are usually hermaphroditic , with the exception of maize , and mainly anemophilous or wind-pollinated, although insects occasionally play

4368-623: The water table and cause salination of aquifers. Fertilizer production contributes to global warming , and its use can lead to pollution and eutrophication of waterways. Arable farming uses large amounts of fossil fuel , releasing greenhouse gases which contribute to global warming. Pesticide usage can cause harm to wildlife, such as to bees . Some of the impacts of growing cereals can be mitigated by changing production practices. Tillage can be reduced by no-till farming , such as by direct drilling of cereal seeds, or by developing and planting perennial crop varieties so that annual tilling

4459-477: The 21st century as people in Asia and elsewhere ate less grain and more meat. An exception is Sub-Saharan Africa, where both per capita consumption of rice and population are increasing. Rice is a commonly-eaten food around the world. The varieties of rice are typically classified as short-, medium-, and long-grained. Oryza sativa indica varieties are usually long-grained; Oryza sativa japonica varieties are usually short- or medium-grained. Short-grain rice, with

4550-643: The Americas by the Spanish. In British North America by the time of the start of the American War of Independence , rice had become the fourth most valuable export commodity behind only tobacco, wheat, and fish. In 2021, world production of rice was 787 million tonnes , led by China and India with a combined 52% of the total. This placed rice fourth in the list of crops by production, after sugarcane , maize , and wheat . Other major producers were Bangladesh , Indonesia and Vietnam . 90% of world production

4641-484: The Americas. For feeding animals , the amount of crude protein measured in grains is expressed as grain crude protein concentration. Cereals constitute the world's largest commodities by tonnage, whether measured by production or by international trade. Several major producers of cereals dominate the market. Because of the scale of the trade, some countries have become reliant on imports, thus cereals pricing or availability can have outsized impacts on countries with

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4732-624: The Hittite Sun goddess of Arinna , the Canaanite Lahmu and the Roman Janus . Complex civilizations arose where cereal agriculture created a surplus, allowing for part of the harvest to be appropriated from farmers, allowing power to be concentrated in cities. During the second half of the 20th century, there was a significant increase in the production of high-yield cereal crops worldwide, especially wheat and rice, due to

4823-464: The Philippines have traditionally managed weeds and pests by the polycultural practice of raising ducks and sometimes fish in their rice paddies. These produce valuable additional crops, eat small pest animals, manure the rice, and in the case of ducks also control weeds. Rice plants produce their own chemical defences to protect themselves from pest attacks. Some synthetic chemicals, such as

4914-446: The advantage of generating larger seedlings that can better compete with other plants. Perennials also produce seeds over many years. An important aspect of cold acclimation is overexpression of DNA repair genes. In Thinopyrum intermedium a perennial relative of common wheat Triticum aestivum , conditions of freezing stress were shown to be associated with large increases in expression of two DNA repair genes (one gene product

5005-485: The advantage of using water when it is plentiful, and permitting a second crop after the early harvest. They flower only in spring as they require vernalization , exposure to cold for a specific period, fixed genetically. Spring crops grow when it is warmer but less rainy, so they may need irrigation. Cereal strains are bred for consistency and resilience to the local environmental conditions. The greatest constraints on yield are plant diseases , especially rusts (mostly

5096-461: The benefits these could bring. In 2022, greenhouse gas emissions from rice cultivation were estimated at 5.7 billion tonnes CO2eq, representing 1.2% of total emissions. Within the agriculture sector, rice produces almost half the greenhouse gas emissions from croplands , some 30% of agricultural methane emissions , and 11% of agricultural nitrous oxide emissions. Methane is released from rice fields subject to long-term flooding, as this inhibits

5187-498: The cereal supply for other countries. Cereals provide food eaten directly as whole grains , usually cooked, or they are ground to flour and made into bread , porridge , and other products. Cereals have a high starch content, enabling them to be fermented into alcoholic drinks such as beer . Cereal farming has a substantial environmental impact , and is often produced in high-intensity monocultures . The environmental harms can be mitigated by sustainable practices which reduce

5278-508: The crop would be lost under these conditions. In the Po Valley in Italy, the arborio and carnaroli risotto rice varieties have suffered poor harvests through drought in the 21st century. The Ente Nazionale Risi  [ it ] is developing drought-resistant varieties; its nuovo prometeo variety has deep roots that enable it to tolerate drought, but is not suitable for risotto. Rice yield can be reduced by weed growth, and

5369-510: The dormancy period is over and new growth begins. In climates that are warm all year long, perennials may grow continuously. Annuals which complete their life cycle in one growing season, in contrast with perennials, produce seeds as the next generation and die; the seeds may survive cold or dry periods or germinate soon after dispersal depending on the climate. Some perennials retain their foliage year-round; these are evergreen perennials. Deciduous perennials shed all their leaves part of

5460-424: The exception of Spanish Bomba, is usually sticky when cooked, and is suitable for puddings. Thai Jasmine rice is aromatic, and unusually for a long-grain rice has some stickiness, with a soft texture. Indian Basmati rice is very long-grained and aromatic. Italian Arborio rice , used for risotto , is of medium length, oval, and quite sticky. Japanese sushi rice is a sticky short-grain variety. Cooked white rice

5551-424: The field where they will grow, or seedlings can be grown in a seedbed and transplanted into the field. Direct seeding needs some 60 to 80 kg of grain per hectare, while transplanting needs less, around 40 kg per hectare, but requires far more labour. Most rice in Asia is transplanted by hand. Mechanical transplanting takes less time but requires a carefully-prepared field and seedlings raised on mats or in trays to fit

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5642-455: The grain, and cleaning by winnowing or screening . The rice grain is dried as soon as possible to bring the moisture content down to a level that is safe from mould fungi. Traditional drying relies on the heat of the sun, with the grain spread out on mats or on pavements. The edible rice species are members of the BOP clade within the grass family, the Poaceae . The rice subfamily, Oryzoideae ,

5733-582: The great diversity and continuous evolution of pests. Resistance genes are being sought from wild species of rice, and genetic engineering techniques are being applied. Cereal grain A cereal is a grass cultivated for its edible grain . Cereals are the world's largest crops, and are therefore staple foods . They include rice , wheat , rye , oats , barley , millet , and maize . Edible grains from other plant families, such as buckwheat and quinoa , are pseudocereals . Most cereals are annuals , producing one crop from each planting, though rice

5824-541: The growing season, and can grow taller than annuals. In doing so they can better compete for space and collect more light. Perennials typically grow structures that allow them to adapt to living from one year to the next through a form of vegetative reproduction rather than seeding. These structures include bulbs , tubers , woody crowns, rhizomes , turions , woody stems, or crowns which allows them to survive periods of dormancy over cold or dry seasons; these structures typically store carbohydrates which are used once

5915-573: The herbicide 2,4-D , cause the plant to increase the production of certain defensive chemicals and thereby increase the plant's resistance to some types of pests. Conversely, other chemicals, such as the insecticide imidacloprid , appear to induce changes in the gene expression of the rice that make the plant more susceptible to certain pests. Plant breeders have created rice cultivars incorporating resistance to various insect pests . Conventional plant breeding of resistant varieties has been limited by challenges such as rearing insect pests for testing, and

6006-620: The hormones produced due to environmental situations (i.e., seasons), reproduction, and stage of development to begin and halt the ability to grow or flower. There is also a distinction between the ability to grow and the actual task of growth. For example, most trees regain the ability to grow during winter but do not initiate physical growth until the spring and summer months. The start of dormancy can be seen in perennial plants through withering flowers, loss of leaves on trees, and halting of reproduction in both flowering and budding plants. Perennial species may produce relatively large seeds that have

6097-749: The impact on soil and improve biodiversity, such as no-till farming and intercropping . Wheat, barley, rye , and oats were gathered and eaten in the Fertile Crescent during the early Neolithic . Cereal grains 19,000 years old have been found at the Ohalo II site in Israel , with charred remnants of wild wheat and barley. During the same period, farmers in China began to farm rice and millet, using human-made floods and fires as part of their cultivation regimen. The use of soil conditioners , including manure , fish, compost and ashes , appears to have begun early, and developed independently in areas of

6188-408: The later years of the 20th century decreased rice yield by between 10% and 20% across 200 farms in seven Asian countries. This may have been caused by increased night-time respiration. IRRI has predicted that Asian rice yields will fall by some 20% per 1°C rise in global mean temperature. Further, rice is unable to yield grain if the flowers experience a temperature of 35 °C or more for over one hour, so

6279-415: The machine. Rice does not thrive if continuously submerged. Rice can be grown in different environments, depending upon water availability. The usual arrangement is for lowland fields to be surrounded by bunds and flooded to a depth of a few centimetres until around a week before harvest time; this requires a large amount of water. The "alternate wetting and drying" technique uses less water. One form of this

6370-509: The need for irrigation, and by breeding new crop varieties. Some cereals such as rice require little preparation before human consumption. For example, to make plain cooked rice , raw milled rice is washed and boiled. Foods such as porridge and muesli may be made largely of whole cereals, especially oats, whereas commercial breakfast cereals such as granola may be highly processed and combined with sugars, oils , and other products. Cereals can be ground to make flour. Wheat flour

6461-426: The other largest exporters. As of 2016, the countries that consumed the most rice were China (29% of total), India, and Indonesia. By 2020, Bangladesh had taken third place from Indonesia. On an annual average from 2020-23, China consumed 154 million tonnes of rice, India consumed 109 million tonnes, and Bangladesh and Indonesia consumed about 36 million tonnes each. Across the world, rice consumption per capita fell in

6552-481: The plant can be allowed to decompose, or collected as straw ; this can be used for animal bedding, mulch, and a growing medium for mushrooms. It is used in crafts such as building with cob or straw-bale construction . If cereals are not completely dry when harvested, such as when the weather is rainy, the stored grain will be spoilt by mould fungi such as Aspergillus and Penicillium . This can be prevented by drying it artificially. It may then be stored in

6643-465: The plants and seeds are dry enough. Harvesting in mechanized agricultural systems is by combine harvester , a machine which drives across the field in a single pass in which it cuts the stalks and then threshes and winnows the grain. In traditional agricultural systems, mostly in the Global South , harvesting may be by hand, using tools such as scythes and grain cradles . Leftover parts of

6734-540: The production of oats and rye has drastically fallen from their 1960s levels. Other cereals not included in the U.N.'s Food and Agriculture Organization statistics include wild rice , which is grown in small amounts in North America, and teff , an ancient grain that is a staple in Ethiopia . Teff is grown in sub-Saharan Africa as a grass primarily for feeding horses. It is high in fiber and protein. Its flour

6825-467: The removal of the bran and germ, all that remains is the starchy endosperm. In some developing countries , cereals constitute a majority of daily sustenance. In developed countries , cereal consumption is moderate and varied but still substantial, primarily in the form of refined and processed grains. Some cereals are deficient in the essential amino acid lysine , obliging vegetarian cultures to combine their diet of cereal grains with legumes to obtain

6916-465: The seed yield of perennial species, which could result in the creation of new perennial grain crops. Some examples of new perennial crops being developed are perennial rice and intermediate wheatgrass . A perennial rice developed in 2018, was reported in 2023, to have provided a similar yield to replanted annual rice when evaluated over eight consecutive harvests. Perennial plants dominate many natural ecosystems on land and in fresh water, with only

7007-1006: The soil from absorbing atmospheric oxygen, resulting in anaerobic fermentation of organic matter in the soil. Emissions can be limited by planting new varieties, not flooding continuously, and removing straw. It is possible to cut methane emissions in rice cultivation by improved water management, combining dry seeding and one drawdown, or executing a sequence of wetting and drying . This results in emission reductions of up to 90% compared to full flooding and even increased yields. Predictions of climate change's effects on rice cultivation vary. Global rice yield has been projected to decrease by around 3.2% with each 1°C increase in global average temperature while another study predicts global rice cultivation will increase initially, plateauing at about 3°C warming (2091–2100 relative to 1850–1900). The impacts of climate change on rice cultivation vary across geographic location and socioeconomic context. For example, rising temperatures and decreasing solar radiation during

7098-668: The spring and summer, die back every autumn and winter, and then return in the spring from their rootstock or other overwintering structure, are known as herbaceous perennials . However, depending on the rigours of the local climate (temperature, moisture, organic content in the soil, microorganisms), a plant that is a perennial in its native habitat, may be treated by a gardener as an annual and planted out every year, from seed, from cuttings, or from divisions. Tomato vines, for example, live several years in their natural tropical/ subtropical habitat but are grown as annuals in temperate regions because their above-ground biomass does not survive

7189-431: The stems. Herbaceous perennials from temperate and alpine regions of the world can tolerate the cold during winter. Perennial plants may remain dormant for long periods and then recommence growth and reproduction when the environment is more suitable, while most annual plants complete their life cycle during one growing period, and biennials have two growing periods. The meristem of perennial plants communicates with

7280-404: The temperature goes above around 30 °C or 85 °F. Warm-season cereals, in contrast, require hot weather and cannot tolerate frost. Cool-season cereals can be grown in highlands in the tropics, where they sometimes deliver several crops in a single year. In the tropics, warm-season cereals can be grown at any time of the year. In temperate zones, these cereals can only be grown when there

7371-641: The voyage to the rest of the Pacific. It reached Austroasiatic and Kra-Dai -speakers in Mainland Southeast Asia and southern China by 5000 years ago. Rice spread around the rest of the world through cultivation, migration and trade, eventually to the Americas as part of the Columbian exchange after 1492. The now less common Oryza glaberrima (African rice) was independently domesticated in Africa around 3,000 years ago, and introduced to

7462-779: The wet season, while thrips outbreaks are associated with drought. Rice blast , caused by the fungus Magnaporthe grisea , is the most serious disease of growing rice. It and bacterial leaf streak (caused by Xanthomonas oryzae pv. oryzae ) are perennially the two worst rice diseases worldwide; they are both among the ten most important diseases of all crop plants. Other major rice diseases include sheath blight (caused by Rhizoctonia solani ), false smut ( Ustilaginoidea virens ), and bacterial panicle blight ( Burkholderia glumae ). Viral diseases include rice bunchy stunt, rice dwarf, rice tungro , and rice yellow mottle. Crop protection scientists are developing sustainable techniques for managing rice pests. Sustainable pest management

7553-405: The winter. There is also a class of evergreen perennials which lack woody stems, such as Bergenia which retain a mantle of leaves throughout the year. An intermediate class of plants is known as subshrubs , which retain a vestigial woody structure in winter, e.g. Penstemon . The symbol for a perennial plant, based on Species Plantarum by Linnaeus , is [REDACTED] , which is also

7644-601: The world including Mesopotamia , the Nile Valley , and Eastern Asia. Cereals that became modern barley and wheat were domesticated some 8,000 years ago in the Fertile Crescent. Millets and rice were domesticated in East Asia, while sorghum and other millets were domesticated in sub-Saharan West Africa, primarily as feed for livestock. Maize arose from a single domestication in Mesoamerica about 9,000 years ago. In these agricultural regions, religion

7735-536: The year provided that sufficient water is made available. It is normally an annual, but in the tropics it can survive as a perennial , producing a ratoon crop. Like all crops, rice depends for its growth on both biotic and abiotic environmental factors. The principal biotic factors are crop variety, pests , and plant diseases . Abiotic factors include the soil type, whether lowland or upland, amount of rain or irrigation water, temperature, day length , and intensity of sunlight. Rice grains can be planted directly into

7826-439: The year. Deciduous perennials include herbaceous and woody plants; herbaceous plants have stems that lack hard, fibrous growth, while woody plants have stems with buds that survive above ground during dormancy. Some perennials are semi-deciduous, meaning they lose some of their leaves in either winter or summer. Deciduous perennials shed their leaves when growing conditions are no longer suitable for photosynthesis, such as when it

7917-464: Was first domesticated in China 9,000 years ago, by people of Neolithic cultures in the Upper and Lower Yangtze , associated with Hmong-Mien -speakers and pre-Austronesians , respectively. The functional allele for nonshattering , the critical indicator of domestication in grains, as well as five other single-nucleotide polymorphisms , is identical in both indica and japonica . This implies

8008-569: Was introduced early into Sino-Tibetan cultures in northern China by around 6000 to 5600 years ago, and to the Korean peninsula and Japan by around 5500 to 3200 years ago. It was also carried into Taiwan by the Dapenkeng culture by 5500 to 4000 years ago, before spreading southwards via the Austronesian migrations to Island Southeast Asia , Madagascar , and Guam , but did not survive

8099-622: Was made in China some 9,000 years ago. Cereals and their related byproducts such as hay are routinely fed to farm animals . Common cereals as animal food include maize, barley, wheat, and oats. Moist grains may be treated chemically or made into silage ; mechanically flattened or crimped, and kept in airtight storage until used; or stored dry with a moisture content of less than 14%. Commercially, grains are often combined with other materials and formed into feed pellets. As whole grains , cereals provide carbohydrates , polyunsaturated fats , protein , vitamins , and minerals . When processed by

8190-496: Was often shaped by the divinity associated with the grain and harvests. In the Mesopotamian creation myth, an era of civilization is inaugurated by the grain goddess Ashnan . The Roman goddess Ceres presided over agriculture, grain crops, fertility, and motherhood; the term cereal is derived from Latin cerealis , "of grain", originally meaning "of [the goddess] Ceres". Several gods of antiquity combined agriculture and war:

8281-435: Was stored by rural households. The dry grain is milled to remove the outer layers, namely the husk and bran . These can be removed in a single step, in two steps, or as in commercial milling in a multi-step process of cleaning, dehusking, separation, polishing, grading, and weighing. Brown rice only has the inedible husk removed. Further milling removes bran and the germ to create successively whiter products. Parboiled rice

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