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54-801: The Dong Son people were skilled at cultivating rice , keeping water buffalos and pigs , fishing and sailing in long dugout canoes . They also were skilled bronze casters , which is evidenced by the Dong Son drum found widely throughout northern Vietnam and Guangxi in China. To the south of the Dong Son culture was the Sa Huỳnh culture of the proto-Chams . The Dongsonians spoke either Austroasiatic or Northern Tai languages ; or were Austroasiatic -speakers with significant contact and admixture with Tai-speakers. Archaeogenetics have demonstrated that before

108-416: 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

162-403: 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

216-411: 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 ,

270-462: 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

324-441: A smooth surface. The leaf is lanceolate, 15–30 cm ( 5 + 7 ⁄ 8 – 11 + 3 ⁄ 4  in) long, and grows from a ligule 10–20 mm ( 3 ⁄ 8 – 3 ⁄ 4  in) long. The generic name Oryza is a classical Latin word for rice, while the specific epithet sativa means "cultivated". Oryza sativa contains two major subspecies: the sticky, short-grained japonica or sinica variety, and

378-423: A variety of colors, including white , brown , black (purple when cooked), and red . A third subspecies, which is broad-grained and thrives under tropical conditions, was identified based on morphology and initially called javanica , but is now known as tropical japonica . Examples of this variety include the medium-grain 'Tinawon' and 'Unoy' cultivars, which are grown in the high-elevation rice terraces of

432-440: 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

486-436: 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

540-678: 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

594-627: 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

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648-504: 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

702-581: 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

756-508: 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

810-812: 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

864-694: 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

918-438: 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

972-538: 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

1026-406: 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

1080-509: 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

1134-471: 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

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1188-494: The Cordillera Mountains of northern Luzon , Philippines. Glaszmann (1987) used isozymes to sort O. sativa into six groups: japonica , aromatic , indica , aus , rayada , and ashina . Garris et al. (2004) used simple sequence repeats to sort O. sativa into five groups: temperate japonica , tropical japonica and aromatic comprise the japonica varieties, while indica and aus comprise

1242-599: The Việt ". Ferlus (2009) showed that the inventions of pestle, oar, and a pan to cook sticky rice, which is the main characteristic of the Đông Sơn culture, correspond to the creation of new lexicons for these inventions in Northern Vietic (Việt–Mường) and Central Vietic ( Cuoi-Toum ). The new vocabularies to denote these inventions were proven to be derivatives from original verbs rather than borrowed lexical items. The current distribution of Northern Vietic also correspond to

1296-440: 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

1350-409: The indica varieties. The Garris scheme has held up against newer analyses as of 2019, though one 2014 article argues that rayada is distinct enough to be its own group under japonica . SPL14 / LOC4345998 is a gene that regulates the overall architecture / growth habit of the plant. Some of its epialleles increase rice yield. An accurate and usable simple sequence repeat marker set

1404-478: 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

1458-704: 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

1512-567: The Dong Son period, the Red River Delta's inhabitants were predominantly Austroasiatic. Genetic data from Vietnam's Phùng Nguyên culture 's Mán Bạc burial site demonstrated close proximity to modern Austroasiatic speakers such as the Khmer and Mlabri ; meanwhile, "mixed genetics" from Đông Sơn culture 's Núi Nấp site showed affinity to " Dai from China, Tai-Kadai speakers from Thailand, and Austroasiatic speakers from Vietnam, including

1566-765: The Iron Age. The bronze drums were used for war, "the chief summons the warriors of the tribe by beating the drum", when mourning, and during feasts. "The scenes cast onto the drums would inform us that the Dong Son leaders had access to bronze founders of remarkable skill." Lost-wax casting was based on Chinese founders , but the scenes are local, including drummers and other musicians, warriors, rice processing, birds, deer, war vessels, and geometric designs. The bronze drums were made in significant proportions in northern Vietnam, Laos and parts of Yunnan . The Dong Son bronze drums exhibit "remarkable skill". The Cổ Loa drum weighs 72 kilograms (159 lb) and would have required

1620-466: 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

1674-517: The area of Dong Son culture. Thus, Ferlus conclude that the Dongsonian culture was of Vietic origin and they were the direct ancestors of modern Vietnamese people . The origins of Dong Son culture may be traced back to ancient bronze castings. Scholars traditionally traced the origins of bronze-casting technology to China but during the 1970s archaeological discoveries in Isan , Thailand found that

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1728-465: 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

1782-530: The casting of bronze either began in Southeast Asia first then spread into China, or that it developed the practise independently from China. The Dong Son bronze industry therefore has a local origin in Southeast Asia rather than being introduced by migrations out of China. The Gò Mun culture gave rise to the Dong Son culture; the Dong Son was the culmination of the Bronze Age and the opening stage of

1836-511: 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

1890-425: 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

1944-425: 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

1998-511: 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 ,

2052-403: 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. Oryza sativa Oryza sativa , having the common name Asian cultivated rice , is the much more common of the two rice species cultivated as a cereal , the other species being O. glaberrima , African rice. It

2106-575: 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

2160-410: 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

2214-417: 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

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2268-762: The nonsticky, long-grained indica [ zh ] [ ja ] rice variety. Japonica was domesticated in the Yangtze Valley 9–6,000 years ago, and its varieties can be cultivated in dry fields (it is cultivated mainly submerged in Japan), in temperate East Asia, upland areas of Southeast Asia, and high elevations in South Asia, while indica was domesticated around the Ganges 8,500–4,500 years ago, and its varieties are mainly lowland rices, grown mostly submerged, throughout tropical Asia. Rice grain occurs in

2322-428: 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

2376-405: The rice blast fungus Magnaporthe grisea is provided by various resistance genes including Pi1 , Pi54 , and Pita . O. sativa uses the plant hormones abscisic acid and salicylic acid to regulate immune responses. Salicylic acid broadly stimulates, and abscisic acid suppresses, immunity to M. grisea ; success depends on the balance between their levels. O. sativa has

2430-488: The smelting of between 1 and 7 tonnes (1.1 and 7.7 tons) of copper ore. Displays of the Đông Sơn drum surface can be seen in some of Vietnam's cultural institutions. Some of Dong Son bronze daggers closely resemble Scytho-Siberian styles . Rice 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

2484-1011: 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

2538-648: 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

2592-785: 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

2646-539: 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

2700-556: Was first domesticated in the Yangtze River basin in China 13,500 to 8,200 years ago. Oryza sativa belongs to the genus Oryza and the BOP clade in the grass family Poaceae . With a genome consisting of 430   Mbp across 12 chromosomes , it is renowned for being easy to genetically modify and is a model organism for the study of the biology of cereals and monocots . O. sativa has an erect stalk stem that grows 80–120 cm (30–45 in) tall, with

2754-843: Was developed and used to generate a high-density map . A multiplex high-throughput marker assisted selection system has been developed but as with other crop HTMAS systems has proven difficult to customize, costly (both directly and for the equipment), and inflexible. Other molecular breeding tools have produced rice blast resistant cultivars. DNA microarray has been used to advance understanding of hybrid vigor in rice, QTL sequencing has been used to elucidate seedling vigor, and genome wide association study (GWAS) by whole genome sequencing (WGS) has been used to investigate various agronomic traits . In total, 641 copy number variations are known. Exome capture often reveals new single nucleotide polymorphisms in rice, due to its large genome and high degree of DNA repetition. Resistance to

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2808-469: 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

2862-574: 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

2916-439: 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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