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Rice

2007 Schools Wikipedia Selection. Related subjects: Food and agriculture

         How to read a taxoboxRice
   Oryza sativa
   Oryza sativa
         Scientific classification

   Kingdom:  Plantae
   Division: Magnoliophyta
   Class:    Liliopsida
   Order:    Poales
   Family:   Poaceae
   Genus:    Oryza

                                   Species

     * Oryza glaberrima
     * Oryza sativa

   The planting of rice is often a labour-intensive process
   The planting of rice is often a labour-intensive process
   Terrace of rice paddies in Yunnan Province, southern China.
   Terrace of rice paddies in Yunnan Province, southern China.

   Rice is two species in the Poaceae ("true grass") family, Oryza sativa
   and Oryza glaberrima. These plants are native to tropical and
   subtropical southern and southeastern Asia and in Africa. Rice provides
   more than one fifth of the calories consumed by humans in their global
   diets. (The term "wild rice" can refer to wild species of Oryza, but
   conventionally refers to species of the related genus Zizania, both
   wild and domesticated.) Rice is a monocarpic annual plant, growing to
   1–1.8 m tall, occasionally more depending on the variety and soil
   fertility. The grass has long, slender leaves 50–100 cm long and 2–2.5
   cm broad. The small wind-pollinated flowers are produced in a branched
   arching to pendulous inflorescence 30–50 cm long. The seed is a grain
   (caryopsis) 5–12 mm long and 2–3 mm thick.

   Rice is a staple for a large part of the world's human population,
   especially in East and Southeast Asia, making it the most consumed
   cereal grain. Rice is the world's third largest crop, behind maize
   ("corn") and wheat. Rice cultivation is well-suited to countries and
   regions with low labour costs and high rainfall, as it is very
   labour-intensive to cultivate and requires plenty of water for
   irrigation, much like the licorice crops found in Eastern Europe. Rice
   can be grown practically anywhere, even on steep hillsides. Although
   its species are native to South Asia and certain parts of Africa,
   centuries of trade and exportation have made it commonplace in many
   cultures.

Growth

   Rice is often grown in paddies. The shallow puddles take advantage of
   the rice plant's tolerance to water; the water in the paddies prevents
   weeds from outgrowing the crop. Once the rice has established dominance
   of the field, the water can be drained in preparation for harvest.
   Paddies increase productivity, although rice can also be grown on dry
   land (including on terraced hillsides) with the help of chemical weed
   controls.

   In some instances, a deep-water strain of rice often called floating
   rice is grown. Floating rice can develop elongated stems capable of
   coping with water depths exceeding 2 meters (6.5 feet).

   Rice paddies are an important habitat for birds such as herons and
   warblers, and a wide range of amphibians and snakes. They perform a
   useful function in controlling insect pests by providing useful
   habitats for those who prey on them. For most farm families in the
   Greater Mekong Subregion the rice field is the main source of household
   food security. Not only does rice itself provide most of the calories
   in the rural diet, but the rice paddy is an important source of wild
   and cultivated fish .

   Rice blast, caused by the fungus Magnaporthe grisea, is the most
   significant disease affecting rice cultivation.

Preparation as food

   Old fashioned way of rice polishing in Japan.
   Old fashioned way of rice polishing in Japan.

   The seeds of the rice plant are first milled using a rice huller to
   remove the chaff (the outer husks of the grain). At this point in the
   process the product is called brown rice. This process may be
   continued, removing the germ and the rest of the husk, called the bran
   at this point, creating white rice. The white rice may then be buffed
   with glucose or talc powder (often called polished rice, though this
   term may also refer to white rice in general), parboiled, or processed
   into flour. The white rice may also be enriched by adding nutrients,
   especially those lost during the milling process. While the cheapest
   method of enriching involves adding a powdered blend of nutrients that
   will easily wash off (in the United States, rice which has been so
   treated requires a label warning against rinsing), more sophisticated
   methods apply nutrients directly to the grain, coating the grain with a
   water insoluble substance which is resistant to washing.
   Terraced rice paddy on a hillslope
   Terraced rice paddy on a hillslope

   While washing is counter-productive for powder-enriched rice, it is
   absolutely necessary when talc-coated rice is used, not least because
   of concerns about the negative health effects of talc consumption and
   possibility of asbestos accompanying the talc. Despite the hypothetical
   health risks of talc (such as stomach cancer), talc-coated rice remains
   the norm in some countries due to its attractive shiny appearance, but
   it has been banned in some and is no longer widely used in others such
   as the United States. Even where talc is not used, glucose, starch, or
   other coatings may be used to improve the appearance of the grains; for
   this reason, many rice lovers still recommend washing all rice in order
   to create a better-tasting rice with a better consistency, despite the
   recommendation of suppliers. Much of the rices produced today are in
   fact water polished.
   Modern rice polishing machines
   Modern rice polishing machines

   Rice bran, called nuka in Japan, is a valuable commodity in Asia and is
   used for many daily needs. It is a moist, oily inner layer which is
   heated to produce an oil. It is also used in making a kind of pickled
   vegetable.

   The raw rice may be ground into flour for many uses, including making
   many kinds of beverages such as amazake, horchata, rice milk, and sake.
   Rice flour is generally safe for people on a gluten-free diet. Rice may
   also be made into various types of noodles.

   The processed rice seeds are usually boiled or steamed to make them
   edible, after which they may be fried in oil or butter, or beaten in a
   tub to make mochi.
                 Rice, raw
   Nutritional value per 100 g (3.527 oz)
     Energy 360 kcal   1510 kJ

   Carbohydrates       79 g
   Fat                 0.6 g
   Protein             7 g
   Vitamin B6  0.15 mg 12%
   Water               13 g
   Percentages are relative to US
   recommendations for adults.

   Rice, like other cereal grains, can be puffed (or popped). This process
   takes advantage of the grains' water content and typically involves
   heating grain pellets in a special chamber. Further puffing is
   sometimes accomplished by processing pre-puffed pellets in a low-
   pressure chamber. The ideal gas law means that either lowering the
   local pressure or raising the water temperature results in an increase
   in volume prior to water evaporation, resulting in a puffy texture.

Cooking

   Uncooked pre-steamed long rice
   Uncooked pre-steamed long rice

   Rice is cooked by boiling or steaming. It can be cooked in just enough
   water to cook it through (the absorption method), or it can be cooked
   in a large quantity of water which is drained before serving (the
   rapid-boil method). Electric rice cookers, which are popular in Asia
   and Latin America, simplify the process of cooking rice.

   Rice may also be made into rice porridge by adding more water than
   usual, so that the cooked rice is saturated with water to the point
   that it becomes very soft, expanded, and fluffy. Rice porridge is very
   easy to digest, so it is especially suitable for the sick.

   Rice may be soaked prior to cooking. Soaked rice cooks faster. For some
   varieties, soaking improves the texture of the cooked rice by
   increasing expansion of the grains.

   In some culinary traditions, especially those of Latin America, Italy,
   and Turkey dry rice grains are fried in oil before cooking in water.

   Much of today's rice is consumed as parboiled rice. Also known as
   easi-cook rice. Parboiled rice is subjected to a steaming or parboiling
   process while still a brown rice. This causes nutrients from the outer
   husk to move into the grain itself. The parboil process causes a
   gelatisisation of the starch in the grains. The grains become less
   brittle, and the colour of the milled grain changes from white to
   yellow. The rice is then dried, and can then be milled as usual or
   consumed as brown rice. Milled parboil rice is nutritionally superior
   to standard milled rice. Parboiled rice has an additional benefit in
   that it does not stick to the pan during cooking as happens when
   cooking regular white rice.

   A nutritionally superior method of preparing brown rice known as GABA
   Rice or GBR (Germinated Brown Rice) may be used. This involves soaking
   washed brown rice for 20 hours in warm water (38 °C or 100 °F) prior to
   cooking it. This process stimulates germination, which activates
   various enzymes in the rice. By this method, a result of research
   carried out for the United Nations Year of Rice, it is possible to
   obtain a more complete amino acid profile, including GABA.

History

   Utagawa Hiroshige, Rice field in Oki province, view of O-Yama.
   Utagawa Hiroshige, Rice field in Oki province, view of O-Yama.

Etymology

   It is widely accepted that the term Rice comes from the Tamil word for
   rice Arisi. According to Microsoft Encarta Dictionary (2004) and to
   Chambers Dictionary of Etymology (1988), the word rice has an
   Indo-Iranian origin. It came to English from Greek óryza, via Latin
   oriza, Italian riso and finally Old French ris (the same as present day
   French riz).
   The same Indo-Iranian origin produced the Arabic ar-ruzz, from which
   the Portuguese and Spanish word arroz originated. Orzo, a pasta shaped
   like small grains of rice, presumably gets its name from the Latin
   oriza.

Genetic History

   Japanese short-grain rice
   Japanese short-grain rice

   Rice is considered to have begun simultaneously in many countries over
   6500 years ago. Two species of rice were domesticated, Asian rice (O.
   sativa) and African rice (O. glaberrima).

   One genetic study suggests that common wild rice, Oryza rufipogon, was
   the wild ancestor of Asian rice. However, the description that Zohary
   and Hopf (2000) provide suggests that rice was cultivated at three
   separate locations, as shown by the three groups of cultivars: the
   short-grained "japonica" or "sinica" varieties, exemplified by Japanese
   rice; the long-grained "indica" varieties, exemplified by Basmati rice;
   and the broad-grained "javonica" varieties, which thrive under tropical
   conditions. However Zohary and Hopf note that the earliest find site
   for the javonica variety, dated to the fifth millennium BC, was in the
   earliest phases of the Hemudu culture on the south side of Hangzhou Bay
   in China, but was found along with japonica types.

   According to Londo and Chiang, O. sativa appears to have originated
   around the foothills of the Himalayas, with O. sativa var. indica on
   the Indian side and O. sativa var. japonica on the Chinese and Japanese
   side.

East Asia

   The origins of rice cultivation is the object of research of
   specialized branch of archaeology called palaeoethnobotany. Research in
   China is active, well reported, and there are a number of differing
   perspectives on when rice was domesticated, and when the intensive
   cultivation of domesticated rice first began.

   China

   Z. Zhao, a Chinese palaeoethnobotanist, hypothesizes that people of the
   Late Pleistocene began to collect wild rice. Zhao explains that the
   collection of wild rice from an early date eventually led to its
   domestication and then the exclusive use of domesticated rice strains
   by circa 6400 B.C. at the latest (Zhao 1998). Stone tool evidence from
   the Yunchanyan site in Hunan province suggests the possibility that
   Early Neolithic groups cultivated rice as early as circa 9000 B.C.
   (Crawford and Shen 1998:862). Crawford and Shen point out that
   calibrated radiocarbon dates show that direct evidence of the earliest
   cultivated rice is no older than 7000 B.C. (Crawford and Shen
   1998:862). Jared Diamond, a biologist and popular science author,
   summarizes some of the work done by professional archaeologists
   mentioned above and estimates that the earliest attested domestication
   of rice took place in China by 7500 B.C.

   One early findspot of rice from Pengtoushan in the Hupei basin was
   dated by AMS radiocarbon techniques to 6400–5800 BC (Zohary and Hopf
   2000), but most of the Neolithic sites in China with finds of charred
   rice and radiocarbon dates are from 5000 BC or later (Crawford and Shen
   1998). This evidence leads most archaeologists to say that large-scale
   dry-land rice farming began between 5000 and 4500 BC in the area of
   Yangtze Delta (for example Hemudu culture, discovered in 1970s), and
   the wet-rice cultivation began at approximately 2500 BC in the same
   area ( Liangzhu culture). It is now commonly thought that some areas
   such as the alluvial plains in Shaoxing and Ningbo in Zhejiang province
   are the cradle-lands of East Asian rice cultivation. Finally, ancient
   textual evidence of the cultivation of rice in China dates to 3000
   years ago.

   Korea and Japan

   In 2003 archaeologists alleged that they discovered burnt grains
   (domesticated rice) in Soro-ri, Korea, that predate the oldest grains
   in China. This find potentially challenges the mainstream explanation
   that domesticated rice originated in China. Unfortunately, the media
   reports of the Soro-ri charred grains are brief and lack sufficient
   detail for archaeologists and other scientists to properly evaluate the
   true meaning of this very unusual find.

   Reliable, mainstream archaeological evidence derived from
   palaeoethnobotanical investigations indicate that dry-land rice was
   introduced to Japan and Korea some time between 3500 and 1200 BC. The
   cultivation of rice in Korea and Japan during that time occurred on a
   small-scale, fields were impermanent plots, and evidence shows that in
   some cases domesticated and wild grains were planted together. The
   technological, subsistence, and social impact of rice and grain
   cultivation is not evident in archaeological data until after 1500 BC.
   For example, intensive wet- paddy rice agriculture was introduced into
   Korea shortly before or during the Middle Mumun Pottery Period (c.
   850–550 BC) and reached Japan by the Final Jomon or Initial Yayoi circa
   300 BC (Crawford and Lee 2003; Crawford and Shen 1998).

India

   It is generally assumed that the Rigveda's have no mention of rice.
   There is however mention of ApUpa, Puro-das and Odana (rice-gruel) in
   the Rig Veda, terms that, at least in later texts, refer to rice
   dishes, The rigvedic commentator Sayana refers to "tandula" when
   commenting on RV 1.16.2., which usually means rice. It was also
   speculated that the rigvedic term dhana (dhanaa, dhanya) could possibly
   refer to rice. Both Charaka and Sushruta mention rice in some detail.
   The Arthasastra discusses some aspects of rice cultivation. The
   Kashyapiyakrishisukti by Kashyapa is the most detailed ancient Sanskrit
   text on rice cultivation.

Africa

   African rice has been cultivated for 3500 years. Between 1500 and 800
   BC, O. glaberrima propagated from its original centre, the Niger River
   delta, and extended to Senegal. However, it never developed far from
   its original region. Its cultivation even declined in favour of the
   Asian species, possibly brought to the African continent by Arabs
   coming from the east coast between the 7th and 11th centuries CE.
   The rice motif on this five-yen coin underscores the importance of the
   grain to the people of Japan
   The rice motif on this five-yen coin underscores the importance of the
   grain to the people of Japan

Near East and Europe

   According to Zohary and Hopf (2000, p. 91), O. sativa was introduced to
   the Middle East and in Hellenistic times, and was familiar to both
   Greek and Roman writers. They report that a large sample of rice grains
   was recovered from a grave at Susa in Iran (dated to the first century
   AD) at one end of the ancient world, while at the same time rice was
   grown in the Po valley in Italy. However, Pliny the Elder writes that
   rice (oryza) is grown only in "Egypt, Syria, Cilicia, Asia Minor and
   Greece" ( N.H. 18.19). The Moors brought it to the Iberian Peninsula
   when they conquered it in 711. After the middle of the 15th century,
   rice spread throughout Italy and then France, later propagating to all
   the continents during the great age of European exploration.

The Americas

   In 1694, rice arrived in South Carolina, probably originating from
   Madagascar. The Spanish brought rice to South America at the beginning
   of the 18th century.

   In the United States, colonial South Carolina and Georgia grew and
   amassed great wealth from the slave labour obtained from the Senegambia
   area of West Africa. At the port of Charleston, through which 40% of
   all American slave imports passed, slaves from this region of Africa
   brought the highest prices, in recognition of their prior knowledge of
   rice culture, which was put to use on the many rice plantations around
   Georgetown, Charleston, and Savannah. From the slaves, plantation
   owners learned how to dyke the marshes and periodically flood the
   fields. At first the rice was milled by hand with wooden paddles, then
   winnowed in sweetgrass baskets (the making of which was another skill
   brought by the slaves). The invention of the rice mill increased
   profitability of the crop, and the addition of water power for the
   mills in 1787 by millwright Jonathan Lucas was another step forward.
   Rice culture in the southeastern U.S. became less profitable with the
   loss of slave labour after the American Civil War, and it finally died
   out just after the turn of the 20th century. The predominant strain of
   rice in the Carolinas was from Africa and was known as "Carolina Gold."
   The cultivar has been preserved and there are current attempts to
   reintroduce it as a commercially grown crop.

World production and trade

                                        Top Paddy Rice Producers — 2005
                                                     (million metric ton)
                             Flag of People's Republic of China  China 185
                                                  Flag of India  India 129
                                          Flag of Indonesia  Indonesia  54
                                        Flag of Bangladesh  Bangladesh  40
                                              Flag of Vietnam  Vietnam  36
                                            Flag of Thailand  Thailand  27
                                              Flag of Myanmar  Myanmar  25
                                            Flag of Pakistan  Pakistan  18
                                      Flag of Philippines  Philippines  15
                                                Flag of Brazil  Brazil  13
                                                  Flag of Japan  Japan  11
                                                           World Total 700
                                                                  Source:
                                UN Food & Agriculture Organisation (FAO)

   World production of rice has risen steadily from about 200 million tons
   of paddy rice in 1960 to 600 million tons in 2004. Milled rice is about
   68% of paddy rice by weight. In the year 2004, the top three producers
   were China (31% of world production), India (20%), and Indonesia (9%).

   World trade figures are very different, as only about 5–6% of rice
   produced is traded internationally. The largest three exporting
   countries are Thailand (26% of world exports), Vietnam (15%), and the
   United States (11%), while the largest three importers are Indonesia
   (14%), Bangladesh (4%), and Brazil (3%).

   Rice is the most important crop in Asia. In Cambodia, for example, 90%
   of the total agricultural area is used for rice production (see "The
   Burning of the Rice" by Don Puckridge for the story of rice production
   in Cambodia ).

Rice pests

   Rice pests are any organisms or microbes with the potential to reduce
   the yield or value of the rice crop (or of rice seeds) (Jahn et al
   2007). Rice pests include weeds, pathogens, insects, rodents, and
   birds. A variety of factors can contribute to pest outbreaks, including
   the overuse of pesticides and high rates of nitrogen fertilizer
   application (e.g. Jahn et al. 2005) . Weather conditions also
   contribute to pest outbreaks. For example, rice gall midge and army
   worm outbreaks tend to follow high rainfall early in the wet season,
   while thrips outbreaks are associated with drought ( Douangboupha et
   al. 2006).

   One of the challenges facing crop protection specialists is to develop
   rice pest management techniques which are sustainable. In other words,
   to manage crop pests in such a manner that future crop production is
   not threatened (Jahn et al. 2001). Rice pests are managed by cultural
   techniques, pest-resistant rice varieties, and pesticides (which
   include insecticide). Increasingly, there is evidence that farmers'
   pesticide applications are often unnecessary (Jahn et al. 1996,
   2004a,b) . By reducing the populations of natural enemies of rice pests
   (Jahn 1992), misuse of insecticides can actually lead to pest outbreaks
   (Cohen et al. 1994). Botanicals, so-called “natural pesticides”, are
   used by some farmers in an attempt to control rice pests, but in
   general the practice is not common. Upland rice is grown without
   standing water in the field. Some upland rice farmers in Cambodia
   spread chopped leaves of the bitter bush (Chromolaena odorata (L.))
   over the surface of fields after planting. The practice probably helps
   the soil retain moisture and thereby facilitates seed germination.
   Farmers also claim the leaves are a natural fertilizer and helps
   suppress weed and insect infestations (Jahn et al. 1999).

   Among rice cultivars there are differences in the responses to, and
   recovery from, pest damage ( Jahn et al. 2004c, Khiev et al. 2000).
   Therefore, particular cultivars are recommended for areas prone to
   certain pest problems. Major rice pests include the brown planthopper
   (Preap et al. 2006), armyworms , the green leafhopper, the rice gall
   midge (Jahn and Khiev 2004), the rice bug (Jahn et al. 2004c), hispa
   (Murphy et al. 2006), the rice leaffolder, stemborer, rats (Leung et al
   2002), and the weed Echinochloa crusgali (Pheng et al. 2001). Major
   rice diseases include Rice Ragged Stunt, Sheath Blight and Tungro.

Cultivars

   The largest collection of rice cultivars is at the International Rice
   Research Institute ( IRRI), with over 100,000 rice accessions held in
   the International Rice Genebank . Rice cultivars are often classified
   by their grain shapes and texture. For example, Thai Jasmine rice is
   long-grain and relatively less sticky, as long-grain rice contains less
   amylopectin than short-grain cultivars. Chinese restaurants usually
   serve long-grain as plain unseasoned steamed rice. Japanese mochi rice
   and Chinese sticky rice are short-grain. Chinese people use sticky rice
   which is properly known as "glutinous rice" (note: glutinous refer to
   the glue-like characteristic of rice; does not refer to "gluten") to
   make zongzi. The Japanese table rice is a sticky, short-grain rice.
   Japanese sake rice is another kind as well.

   Indian rice cultivars include long-grained and aromatic Basmati (grown
   in the North), long and medium-grained Patna rice and short-grained
   Masoori. In South India the most prized cultivar is 'ponni' which is
   primarily grown in the delta regions of Kaveri River. Kaveri is also
   referred to as ponni in the South and the name reflects the geographic
   region where it is grown. Rice in East India and South India, is
   usually prepared by boiling the rice in large pans immediately after
   harvesting and before removing the husk; this is referred to in English
   as parboiled rice. It is then dried, and the husk removed later. It
   often displays small red speckles, and has a smoky flavour from the
   fires. Usually coarser rice is used for this procedure. It helps to
   retain the natural vitamins and kill any fungi or other contaminants,
   but leads to an odour which some find peculiar. This rice is easier on
   the stomach to digest. In South India, it is also used to make idlis.
   Brown Rice
   Brown Rice
   Polished sona masuri rice.
   Polished sona masuri rice.

   Aromatic rices have definite aromas and flavours; the most noted
   cultivars are Thai fragrant rice, Basmati, Patna rice, and a hybrid
   cultivar from America sold under the trade name, Texmati. It is a cross
   between Basmati and American long-grained rice that is creating great
   controversy. Both Basmati and Texmati have a mild popcorn-like aroma
   and flavour. In Indonesia there are also red and black cultivars.

   High-yield cultivars of rice suitable for cultivation in Africa and
   other dry ecosystems called the new rice for Africa (NERICA) cultivars
   have been developed. It is hoped that their cultivation will improve
   food security in West Africa.

   Scientists are working on so-called golden rice which is genetically
   modified to produce beta carotene, the precursor to vitamin A.

   Draft genomes for the two most common rice cultivars, indica and
   japonica, were published in April 2002. Rice was chosen as a model
   organism for the biology of grasses because of its relatively small
   genome (~430 mega base pairs). Rice was the first crop with a complete
   genome sequence. Basmati rice is the oldest, common progenitor for most
   types.

   On December 16, 2002, the UN General Assembly declared the year 2004
   the International Year of Rice. The declaration was sponsored by
   Bangladesh, Brunei Darussalam, Burkina Faso, Cambodia, Cuba, Cyprus,
   Democratic People's Republic of Korea, Ecuador, Fiji, Gabon, Grenada,
   Guyana, India, Indonesia, Japan, Kazakhstan, Korea, Kuwait, Kyrgyzstan,
   Lao People's Democratic Republic, Madagascar, Mali, Malaysia, the
   Marshall Islands, Mauritania, Myanmar, Nauru, Nepal, Nicaragua, Niger,
   Nigeria, Papua New Guinea, Pakistan, Peru, Philippines, Saint Vincent
   and the Grenadines, Singapore, Sri Lanka, Sudan, Tajikistan, Thailand,
   Togo, Vietnam, and Zambia.

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