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{{Short description|Cereal (Oryza sativa)}}
{{Short description|Cereal grain and staple food}}
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[[File:White, Brown, Red & Wild rice.jpg|right|upright=1.35|thumb|A mixture of brown, white, and red [[indica rice]], also containing [[wild rice]], ''Zizania'' species]]
[[File:20201102.Hengnan.Hybrid rice Sanyou-1.6.jpg|thumb|upright=1.35|Rice plant (''[[Oryza sativa]]'') with branched [[panicle]]s containing many grains on each stem]]
[[File:Rice grains (IRRI).jpg|thumb|upright=1.35|Rice grains of different [[Variety (botany)|varieties]] at the [[International Rice Research Institute]]]]
'''Rice''' is the [[seed]] of the grass species ''[[Oryza sativa]]'' (Asian rice) or, less commonly, ''[[Oryza glaberrima|O. glaberrima]]'' (African rice). The name [[wild rice]] is usually used for species of the genera ''[[Zizania (genus)|Zizania]]'' and ''[[Porteresia]]'', both wild and domesticated, although the term may also be used for primitive or uncultivated varieties of ''[[Oryza]]''.


'''Rice''' is a [[cereal grain]] and in its [[Domestication|domesticated]] form is the [[staple food]] of over half of the [[world's population]], particularly in [[Asia]] and [[Africa]].<!--'Food security' --> 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.<!--'Phylogeny', 'History'--> Rice has become commonplace in many cultures worldwide; in 2021, 787 million tons were produced, placing it fourth after [[sugarcane]], [[maize]], and [[wheat]].<!--<ref name="faostat16">--> Only some 8% of rice is traded internationally.<!--'Trade'--> China, India, and Indonesia are the largest consumers of rice.<!--'Worldwide consumption'--> A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage.<!--'Food security' --> Rice yields can be reduced by pests including [[insect]]s, [[rodent]]s, and [[bird]]s, as well as by [[weed]]s, and by [[List of rice diseases|diseases]] such as [[rice blast]].<!--'Pests, weeds, and diseases'--> Traditional [[rice polyculture]]s such as [[rice-duck farming]], and modern [[integrated pest management]] seek to control damage from pests in a [[Sustainable agriculture|sustainable]] way.<!--'Integrated pest management'-->
As a [[cereal|cereal grain]], domesticated rice is the most widely consumed [[staple food]] for over half of the world's [[World population|human population]],<ref group="Liu" name="feed-over-half-world">Abstract, "Rice feeds more than half the world's population."</ref> particularly in [[Asia]] and [[Africa]]. It is the agricultural [[commodity]] with the third-highest worldwide production, after [[sugarcane]] and [[maize]].<ref name="faostat16">{{cite web|url=http://www.fao.org/faostat/en/#data/QC|title=Crops/Regions/World list/Production Quantity (pick lists), Rice (paddy), 2018|date=2020|publisher=[[FAOSTAT]] (UN Food and Agriculture Organization, Corporate Statistical Database) |access-date=October 11, 2019|archive-url=https://web.archive.org/web/20170511194947/http://www.fao.org/faostat/en/#data/QC|archive-date=May 11, 2017|url-status=live}}</ref> Since sizable portions of sugarcane and maize crops are used for purposes other than human consumption, rice is the most important food crop with regard to human nutrition and caloric intake, providing more than one-fifth of the [[Food energy|calories]] consumed worldwide by humans.<ref>Smith, Bruce D. (1998) ''The Emergence of Agriculture''. [[Scientific American Library]], A Division of [[HPHLP]], New York, {{ISBN|0-7167-6030-4}}.</ref> There are many varieties of rice, and culinary preferences tend to vary regionally.
[[File:Rice consumption.png|thumb|Annual per capita supply (2019)]]


Many varieties of rice have been bred to improve crop quality and productivity.<!--'Ecotypes and cultivars'--> [[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 [[Crop tolerance to seawater|salt-tolerant]] varieties.<!--'Biotechnology'--> Rice is used as a [[model organism]] in biology.<!--'Model organism'-->
[[File:Oryza sativa of Kadavoor.jpg|thumb|Small [[Anemophily|wind-pollinated]] flowers]]
The traditional method for cultivating rice is flooding the fields while, or after, setting the young seedlings. This simple method requires sound irrigation planning, but it reduces the growth of less robust weed and pest plants that have no submerged growth state, and deters [[vermin]]. While flooding is not mandatory for the cultivation of rice, all other methods of [[irrigation]] require higher effort in [[Weed control|weed]] and [[pest control]] during growth periods and a different approach for fertilizing the soil.


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 rice|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.<!--'Processing'--> Rice of different types is eaten around the world. Long-grain rice tends to stay intact on cooking; medium-grain rice 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.<!--'Food'--> White rice when cooked contains 29% [[carbohydrate]] and 2% protein, with some [[manganese]].<!--'Nutrition'--> [[Golden rice]] is a variety produced by [[genetic engineering]] to contain [[vitamin A]].<!--'Golden rice'-->
[[File:Brown rice cooked.JPG|thumb|Cooked brown rice, [[Bhutan]]]]
[[File:Jumli Marshi.jpg|thumb|Jumli Marshi, brown rice, [[Nepal]]]]
[[File:Rice grains (IRRI).jpg|frameless|right|alt=Many shapes, colors, and sizes]]
[[File:Single grain of rice.png|thumb|Under handmade microscope|alt=Single grain under handmade microscope]]
Rice, a [[Monocotyledon|monocot]], is normally grown as an [[annual plant]], although in [[Tropics|tropical]] areas it can survive as a [[perennial]] and can produce a [[ratoon]] crop for up to 30 years.<ref>{{cite web |url=http://www.knowledgebank.irri.org/riceIPM/IPM_Information/PestEcologyBasics/CropGrowthAndPestDamage/RicePlantHowItGrows/The_Rice_plant_and_How_it_Grows.htm |title=The Rice Plant and How it Grows |website=International Rice Research Institute |archive-url=https://web.archive.org/web/20090106224427/http://www.knowledgebank.irri.org/riceIPM/IPM_Information/PestEcologyBasics/CropGrowthAndPestDamage/RicePlantHowItGrows/The_Rice_plant_and_How_it_Grows.htm |archive-date=January 6, 2009}}</ref> Rice cultivation is well-suited to countries and regions with low [[Labor theory of value|labor costs]] and high [[rain]]fall, as it is labor-intensive to cultivate and requires ample water. However, rice can be grown practically anywhere, even on a steep hill or [[mountain]] area with the use of water-controlling terrace systems. Although its parent species are native to Asia and certain parts of Africa, centuries of trade and exportation have made it commonplace in many cultures worldwide. Production and consumption of rice is estimated to have been responsible for 4% of global [[greenhouse gas emissions]] in 2010.


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 a role in various religions and traditions, such as in [[wedding]]s.<!--'In human culture'-->
[[File:Koeh-232.jpg|right|thumb|[[Botanical illustration]]]]


==Characteristics==
== Description ==
The rice plant can grow to {{cvt|1|–|1.8|m|ft|0}} tall, occasionally more depending on the variety and soil fertility. It has long, slender leaves {{cvt|50|–|100|cm|in|-1}} long and {{cvt|2|–|2.5|cm|in|frac=8}} broad. The small [[Anemophily|wind-pollinated]] flowers are produced in a branched arching to pendulous [[inflorescence]] {{cvt|30|–|50|cm|in|0}} long. The edible seed is a grain ([[caryopsis]]) {{cvt|5|–|12|mm|in|frac=32}} long and {{cvt|2|–|3|mm|in|frac=32}} thick.


The rice plant can grow to over {{cvt|1|m|ft|0}} tall; if in deep water, it can reach a length of {{cvt|5|m|ft|0}}. A single plant may have several leafy stems or [[Tiller (botany)|tillers]]. The upright stem is jointed with [[Node (botany)|nodes]] along its length; a long slender leaf arises from each node.<ref name="RBG Kew botany">{{cite web |title=Oryza sativa L. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:316812-2/general-information |publisher=[[Royal Botanic Gardens, Kew]] |access-date=December 6, 2023}}</ref> The [[Autogamy|self-fertile]] flowers are produced in a [[panicle]], a branched [[inflorescence]] which arises from the last internode on the stem. There can be up to 350 [[spikelet]]s in a panicle, each containing male and female flower parts ([[anther]]s and [[ovule]]). A fertilised ovule develops into the edible grain or [[caryopsis]].<ref name="Rice Hub">{{cite web |title=The Rice Plant |url=http://www.ricehub.org/RT/crop-establishment/-the-rice-plant/ |website=Rice Hub |access-date=December 6, 2023}}</ref>
Rice is a cereal crop belonging to the family [[Poaceae|Poecae]]. Rice being a tropical crop can be grown during the two distinct seasons (dry and wet) of the year provided that moisture is made available to the crop.<ref>{{Cite journal |last1=Kawure |first1=S |last2=Garba |first2=Aa |last3=Fagam |first3=As |last4=Shuaibu |first4=Ym |last5=Sabo |first5=Mu |last6=Bala |first6=Ra |date=December 31, 2022 |title=Performance of Lowland Rice (Oryza sativa L.) as Influenced by Combine Effect of Season and Sowing Pattern in Zigau |url=https://scholars.direct/Articles/rice-research/jrrd-5-027.php?jid=rice-research |journal=Journal of Rice Research and Developments |volume=5 |issue=2 |doi=10.36959/973/440|s2cid=256799161 }}</ref>


Rice is a cereal belonging to the family [[Poaceae]]. As a [[Tropics|tropical]] crop, it can be grown during the two distinct seasons (dry and wet) of the year provided that sufficient water is made available.<ref name="Kawure Garba Fagam 2022">{{cite journal |last1=Kawure |first1=S. |last2=Garba |first2=A.A. |last3=Fagam |first3=A.S. |last4=Shuaibu |first4=Y.M. |last5=Sabo |first5=M.U. |last6=Bala |first6=R.A. |title=Performance of Lowland Rice (Oryza sativa L.) as Influenced by Combine Effect of Season and Sowing Pattern in Zigau |journal=Journal of Rice Research and Developments |date=31 December 2022 |volume=5 |issue=2 |doi=10.36959/973/440 |doi-access=free }}</ref> It is normally an annual, but in the tropics it can survive as a [[perennial]], producing a [[ratoon]] crop.<ref name="IRRI rice plant">{{cite web |url=http://www.knowledgebank.irri.org/riceIPM/IPM_Information/PestEcologyBasics/CropGrowthAndPestDamage/RicePlantHowItGrows/The_Rice_plant_and_How_it_Grows.htm |title=The Rice Plant and How it Grows |website=[[International Rice Research Institute]] |archive-url=https://web.archive.org/web/20090106224427/http://www.knowledgebank.irri.org/riceIPM/IPM_Information/PestEcologyBasics/CropGrowthAndPestDamage/RicePlantHowItGrows/The_Rice_plant_and_How_it_Grows.htm |archive-date=January 6, 2009}}</ref>
==Food==
Rice is commonly consumed as food around the world.


<gallery mode=packed widths=200 heights=200>
===Cooking===
File:Koeh-232.jpg|Anatomy of rice flowers: [[spikelet]] (left), plant with [[Tiller (botany)|tillers]] (centre), [[caryopsis]] (top right), [[panicle]] (right)
The [[List of rice varieties|varieties of rice]] are typically classified as long-, medium-, and short-grained.<ref>{{cite web|date=February 25, 2008|editor=Fine Cooking|title=Guide to Rice|url=http://www.finecooking.com/articles/guide-to-rice.aspx|url-status=live|archive-url=https://web.archive.org/web/20141016030017/http://www.finecooking.com/articles/guide-to-rice.aspx|archive-date=October 16, 2014|access-date=July 24, 2014|publisher=[[Fine Cooking]]}}</ref> The grains of long-grain rice (high in [[amylose]]) tend to remain intact after cooking; medium-grain rice (high in [[amylopectin]]) becomes more sticky. Medium-grain rice is used for sweet dishes, for ''[[risotto]]'' in Italy, and many rice dishes, such as ''[[arròs negre]]'', in Spain. Some varieties of long-grain rice that are high in [[amylopectin]], known as Thai Sticky rice, are usually steamed.<ref>{{cite web| vauthors = Loha-unchit K |title=White Sticky Rice – Kao Niow|url=http://www.thaifoodandtravel.com/ingredients/stickyr.html|url-status=live|archive-url=https://web.archive.org/web/20121013231727/http://thaifoodandtravel.com/ingredients/stickyr.html|archive-date=October 13, 2012|access-date=October 12, 2012}}</ref> A stickier short-grain rice is used for ''[[sushi]]'';<ref name="Kitchen2020">{{cite book|author=America's Test Kitchen|title=The Best of America's Test Kitchen 2021: Best Recipes, Equipment Reviews, and Tastings|url=https://books.google.com/books?id=06gSEAAAQBAJ&pg=PA282|date=October 6, 2020|publisher=[[America's Test Kitchen]]|isbn=978-1-948703-40-6|page=282}}</ref> the stickiness allows rice to hold its shape when cooked.<ref name="Simmons2009">{{cite book|author=Marie Simmons|title=The Amazing World of Rice: with 150 Recipes for Pilafs, Paellas, Puddings, and More|url=https://books.google.com/books?id=TLLu9RLUlLkC&pg=PT23|date=March 10, 2009|publisher=[[HarperCollins]] e-books|isbn=978-0-06-187543-4|page=23}}</ref> Short-grain rice is used extensively in Japan,<ref>{{cite book|title=Foreign Crops and Markets|url=https://books.google.com/books?id=0bojvKVWlvUC&pg=PA850|year=1928|publisher=Department of Agriculture, [[Foreign Agricultural Service]] (USDA FAS) |page=850}}</ref> including to accompany savoury dishes.<ref name="AlfordDuguid2003">{{cite book| vauthors = Alford J, Duguid N |title=Seductions of Rice|url=https://books.google.com/books?id=_0PQHTgRVCEC&pg=PA31|date=January 1, 2003|publisher=Artisan|isbn=978-1-57965-234-0|page=31}}</ref> Short-grain rice is often used for [[rice pudding]].
File:Oryza sativa of Kadavoor.jpg|Detail of rice plant showing flowers grouped in panicle. Male [[anther]]s protrude into the air where they can disperse their [[pollen]].
</gallery>


== Agronomy ==
[[Instant rice]] differs from [[parboiled rice]] in that it is fully cooked and then dried, though there is a significant degradation in taste and texture. Rice flour and [[starch]] often are used in [[Batter (cooking)|batters]] and breadings to increase crispiness.


==== Preparation ====
=== Growing ===
Rinsing rice before cooking removes much of the [[starch]], thereby reducing the extent to which individual grains will stick together. This yields a fluffier rice, whereas not rinsing yields a stickier and creamier result.<ref name="Kenyon">{{cite book| vauthors = Kenyon C |title=Knack Mexican Cooking: A Step-by-Step Guide to Authentic Dishes Made Easy|url=https://books.google.com/books?id=Nv9Dim73f_YC&pg=PA15|publisher= [[Rowman & Littlefield]] |isbn=978-0-7627-6206-4|page=15}}</ref> Rice produced in the US is usually fortified with vitamins and minerals, and rinsing will result in a loss of nutrients.


Like all crops, rice depends for its growth on both biotic and abiotic environmental factors. The principal biotic factors are crop variety, [[Pest (organism)|pests]], and [[plant disease]]s. Abiotic factors include the soil type, whether lowland or upland, amount of rain or irrigation water, temperature, [[Photoperiodism|day length]], and intensity of sunlight.<ref name="Verheye 2010">{{cite book |last=Beighley |first=Donn H. |title=Soils, Plant Growth and Crop Production Volume II |chapter=Growth and Production of Rice |editor-last=Verheye |editor-first=Willy H. |date=2010 |publisher=[[EOLSS]] Publishers |isbn=978-1-84826-368-0 |url=https://www.eolss.net/ebooklib/bookinfo/soils-plant-growth-crop-production.aspx |page=49}}</ref>
Rice may be soaked to decrease cooking time, conserve fuel, minimize exposure to high temperature, and reduce stickiness. For some [[Variety (botany)|varieties]], soaking improves the texture of the cooked rice by increasing expansion of the grains. Rice may be soaked for 30 minutes up to several hours.


Rice grains can be planted directly into 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.<ref name="IRRI planting">{{cite web |url=http://www.knowledgebank.irri.org/step-by-step-production/growth/planting |title=How to plant rice |publisher=[[International Rice Research Institute]] |access-date=December 29, 2023 }}</ref> 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 the machine.<ref name="IRRI transplanting">{{cite web |url=http://www.knowledgebank.irri.org/step-by-step-production/growth/planting/transplanting |title=Transplanting |publisher=[[International Rice Research Institute]] |access-date=December 29, 2023 }}</ref> Rice does not thrive if continuously submerged.<ref name="Cornell 2011">{{cite web |last=Uphoff |first=Norman |url=http://ciifad.cornell.edu/sri/extmats/philmanual.pdf |title=More rice with less water through SRI - the System of Rice Intensification |publisher=[[Cornell University]] |archive-url=https://web.archive.org/web/20111226111455/https://ciifad.cornell.edu/sri/extmats/philmanual.pdf |archive-date=December 26, 2011 |access-date=May 13, 2012 }}</ref> Rice can be grown in different environments, depending upon water availability. The usual arrangement is for lowland fields to be surrounded by [[Bunding|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 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.<ref name="IRRI water mgmt">{{cite web |url=http://www.knowledgebank.irri.org/step-by-step-production/growth/water-management |title=Water Management |publisher=[[International Rice Research Institute]] |access-date=November 4, 2023 }}</ref> [[Deepwater rice]] varieties tolerate flooding to a depth of over 50 centimetres for at least a month.<ref>{{cite book |last=Catling |first=David |chapter=Deepwater Rice Cultures in the Ganges-Brahmaputra Basin |title=Rice in Deep Water |publisher=[[International Rice Research Institute]] |year=1992 |chapter-url=https://books.google.com/books?id=N5JxwKx1RAgC&pg=PA230 |isbn=978-971-22-0005-2 |page=2}}</ref> [[Upland rice]] is grown without flooding, in hilly or mountainous regions; it is [[rainfed]] like wheat or maize.<ref>{{cite book |last1=Gupta |first1=Phool Chand |last2=O'Toole |first2=J. C. O'Toole |year=1986 |title=Upland Rice: A Global Perspective |publisher=[[International Rice Research Institute]] |isbn=978-971-10-4172-4}}</ref>
Brown rice may be soaked in warm water for 20 hours to stimulate [[germination]]. This process, called [[germinated brown rice]] (GBR),<ref>{{cite web| vauthors = Ito S, Ishikawa Y |title=Marketing of Value-Added Rice Products in Japan: Germinated Grown Rice and Rice Bread|url=http://www.hatsuga.com/DOMER/english/en/GBRRB.html|url-status=dead|archive-url=https://web.archive.org/web/20130530221121/http://www.hatsuga.com/DOMER/english/en/GBRRB.html|archive-date=May 30, 2013|access-date=February 12, 2004|publisher=[[Tottori University]]|location=[[Japan]]|name-list-style=amp}}</ref> activates enzymes and enhances amino acids including [[gamma-aminobutyric acid]] to improve the nutritional value of brown rice. This method is a result of research carried out for the United Nations [[International Year of Rice]].


{{multiple image |align=center |caption_align=center |total_width=840 |image_gap=10 |image_style=border:none;
[[File:Tteumul.jpg|thumb|Rice with the water used to wash it]]
|image1=Kerbau Jawa.jpg |caption1=Ploughing a rice terrace with [[Domestic buffalo|water buffaloes]] in [[Java]]
Rice is cooked by [[boiling]] or [[steaming]], and absorbs water during cooking. With the absorption method, rice may be cooked in a volume of water equal to the volume of dry rice plus any evaporation losses.<ref>{{cite AV media |people= Dan Souza|date= November 17, 2018|title=The Best Way to Cook Rice is All About the Right Ratio {{!}} What's Eating Dan? |trans-title= |type= |language= |url= https://www.youtube.com/watch?v=JOOSikanIlI|access-date= |format= |time= |location= |publisher= [[America's Test Kitchen]] |id= |isbn= |oclc= |quote= }}</ref> With the rapid-boil method, rice may be cooked in a large quantity of water which is drained before serving. Rapid-boil preparation is not desirable with enriched rice, as much of the enrichment additives are lost when the water is discarded. Electric [[rice cooker]]s, popular in Asia and Latin America, simplify the process of cooking rice. Rice (or any other grain) is sometimes quickly fried in oil or fat before boiling (for example [[saffron rice]] or [[risotto]]); this makes the cooked rice less sticky, and is a cooking style commonly called [[pilaf]] in [[Iran]] and [[Afghanistan]] or [[biryani]] in [[India]] and [[Pakistan]].
|image2=Cambodian farmers planting rice.jpg |caption2=Farmers planting rice by hand in [[Cambodia]]
|image3=Rice-planting-machine 2,katori-city,japan.JPG |caption3=Mechanised rice planting in Japan
|image4=Pana Banaue Rice Terraces (Cropped).jpg |caption4=Ancient mountainside [[Banaue Rice Terraces|rice terraces at Banaue]], Philippines
}}


====Dishes====
=== Harvesting ===
{{main|List of rice dishes}}
In [[Arab cuisine]], rice is an ingredient of many soups and dishes with fish, poultry, and other types of meat. It is used to stuff vegetables or is wrapped in grape leaves ([[dolma]]). When combined with milk, sugar, and honey, it is used to make desserts. In some regions, such as [[Tabaristan]], bread is made using rice flour. Rice may be made into [[congee]] (also called rice porridge or [[rice gruel]]) by adding more water than usual, so that the cooked rice is saturated with water, usually to the point that it disintegrates. Rice porridge is commonly eaten as a breakfast food, and is a traditional food for the sick.


Across Asia, unmilled rice or "paddy" (Indonesian and Malay {{lang|id|padi}}), was traditionally the product of [[smallholder]] agriculture, with manual [[harvest]]ing. Larger farms make use of machines such as [[combine harvester]]s to reduce the input of labour.<ref name="IRRI Harvesting systems">{{cite web |title=Harvesting systems |url=http://www.knowledgebank.irri.org/step-by-step-production/postharvest/harvesting/harvesting-systems |publisher=[[International Rice Research Institute]] |access-date=January 3, 2024}}</ref> The grain is ready to harvest when the moisture content is 20–25%. Harvesting involves [[reaping]], stacking the cut stalks, [[threshing]] to separate the grain, and cleaning by [[winnowing]] or [[sieve|screening]].<ref name="IRRI Harvesting">{{cite web |title=Harvesting |url=http://www.knowledgebank.irri.org/step-by-step-production/postharvest/harvesting#guidelines-on-proper-harvesting |publisher=[[International Rice Research Institute]] |access-date=December 6, 2023}}</ref> 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.<ref name="IRRI Drying">{{cite web |title=Drying |url=http://www.knowledgebank.irri.org/step-by-step-production/postharvest/drying |publisher=[[International Rice Research Institute]] |access-date=December 6, 2023}}</ref>
===Nutrition===
Rice is the [[staple food]] of over half the world's population. It is the predominant dietary energy source for 17 countries in Asia and the Pacific, 9 countries in North and South America and 8 countries in Africa. Rice provides 20% of the world's dietary energy supply, while wheat supplies 19% and maize (corn) 5%.<ref>{{cite web|title=Rice is Life|publisher= United Nations [[Food and Agriculture Organization]] (FAO) |year=2004|url=http://www.fao.org/rice2004/en/f-sheet/factsheet3.pdf|access-date=November 21, 2011|archive-url=https://web.archive.org/web/20111110193515/http://www.fao.org/rice2004/en/f-sheet/factsheet3.pdf|archive-date=November 10, 2011|url-status=live}}</ref>


{{multiple image |align=center |caption_align=center |total_width=840 |image_gap=10 |image_style=border:none;
Cooked unenriched long-grain white rice is composed of 68% water, 28% [[carbohydrates]], 3% [[protein]], and 1% [[fat]] (table). A {{convert|100|g|oz|abbr=off|adj=on|frac=2}} reference serving of it provides {{convert|130|kcal|kJ|order=flip|abbr=off}} of [[food energy]] and contains no [[micronutrient]]s in significant amounts, with all less than 10% of the [[Daily Value]] (DV) (table). Cooked short-grain white rice provides the same food energy and contains moderate amounts of [[B vitamins]], [[iron]], and [[manganese]] (10–17% DV) per 100-gram serving (table).
|image1=Rice-combine-harvester, Katori-city, Japan.jpg |caption1=Rice [[combine harvester]] in [[Chiba Prefecture]], Japan
|image2=Rice farmers Mae Wang Chiang Mai Province.jpg |caption2=After the harvest, rice straw is gathered in the traditional way from small paddy fields in [[Mae Wang]], Thailand
|image3=NP India burning 48 (6315309342).jpg |caption3=Burning of rice residues to prepare the land for [[wheat]] planting in [[Sangrur]], India
|image4=Nellu.JPG |caption4=Drying rice in [[Peravoor]], India
}}


== Evolution ==
A detailed analysis of nutrient content of rice suggests that the nutrition value of rice varies based on a number of factors. It depends on the strain of rice, such as [[white rice|white]], [[brown rice|brown]], [[red rice|red]], and [[black rice|black]] (or purple) varieties having different prevalence across world regions.<ref name="who2018">{{cite book |title=Guideline: Fortification of rice with vitamins and minerals as a public health strategy |url=http://apps.who.int/iris/bitstream/handle/10665/272535/9789241550291-eng.pdf?ua=1 |publisher=[[World Health Organization]] (WHO)|isbn=978-92-4-155029-1 |access-date=August 7, 2018 |date=2018}}</ref> It also depends on nutrient quality of the soil rice is grown in, whether and how the rice is polished or processed, the manner it is enriched, and how it is prepared before consumption.<ref>{{cite web|title=Rice in human nutrition|year=1993|publisher=United Nations [[Food and Agriculture Organization]] (FAO)| vauthors = Juliano BO |url=http://www.fao.org/docrep/T0567E/T0567E00.htm|access-date=November 21, 2011|archive-url=https://web.archive.org/web/20111001002157/http://www.fao.org/docrep/T0567E/T0567E00.htm|archive-date=October 1, 2011|url-status=live}}</ref>


=== Phylogeny ===
A 2018 [[World Health Organization]] (WHO) guideline showed that [[food fortification|fortification]] of rice to reduce [[malnutrition]] may involve different micronutrient strategies, including [[iron]] only, iron with [[zinc]], [[vitamin A]], and [[folic acid]], or iron with other [[B vitamins|B-complex vitamins]], such as [[thiamin]], [[Niacin (nutrient)|niacin]], [[vitamin B6]], and [[pantothenic acid]].<ref name=who2018/> A [[systematic review]] of [[clinical research]] on the efficacy of rice fortification showed the strategy had the main effect of reducing the risk of [[iron deficiency]] by 35% and increasing blood levels of [[hemoglobin]].<ref name=who2018/> The guideline established a major recommendation: "Fortification of rice with iron is recommended as a public health strategy to improve the iron status of populations, in settings where rice is a staple food."<ref name=who2018/>


{{further|Oryza sativa}}
Rice grown experimentally under elevated [[carbon dioxide]] levels, similar to those predicted for the year 2100 [[Carbon dioxide in Earth's atmosphere|as a result of human activity]], had less iron, zinc, and protein, as well as lower levels of thiamin, [[riboflavin]], folic acid, and pantothenic acid.<ref>{{Cite journal| vauthors = Wishart S |date=July–August 2018|title=Second-rate grains|url=https://www.nzgeo.com/stories/second-rate-grains/|journal=New Zealand Geographic|issue=152|page=25|access-date=August 3, 2018|archive-url=https://web.archive.org/web/20180803074429/https://www.nzgeo.com/stories/second-rate-grains/|archive-date=August 3, 2018|url-status=live}}</ref>
The following table shows the nutrient content of rice and other major staple foods in a raw form on a [[Dry matter#Dry matter basis|dry weight basis]] to account for their different water contents.<ref>{{cite web|title=USDA National Nutrient Database for Standard Reference |publisher= [[United States Department of Agriculture]] (USDA) |url=http://www.nal.usda.gov/fnic/foodcomp/search/ |url-status=dead |archive-url=https://web.archive.org/web/20150303184216/http://www.nal.usda.gov/fnic/foodcomp/search/ |archive-date=March 3, 2015 }}</ref>
{{Comparison of major staple foods}}


The edible rice species are members of the [[BOP clade]] within the grass family, the [[Poaceae]]. The rice subfamily, [[Oryzoideae]], 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.<ref name="Soreng Peterson 2017">{{cite journal |last1=Soreng |first1=Robert J. |last2=Peterson |first2=Paul M. |last3=Romaschenko |first3=Konstantin |last4=Davidse |first4=Gerrit |last5=Teisher |first5=Jordan K. |last6=Clark |first6=Lynn G. |last7=Barberá |first7=Patricia |last8=Gillespie |first8=Lynn J. |last9=Zuloaga |first9=Fernando O. |title=A worldwide phylogenetic classification of the Poaceae (Gramineae) II: An update and a comparison of two 2015 classifications |journal=Journal of Systematics and Evolution |volume=55 |issue=4 |year=2017 |pages=259–290 |doi=10.1111/jse.12262 |doi-access=free |hdl=10261/240149 |hdl-access=free }}</ref>
{{Nutritional value

| image = [[File:Rice p1160004.jpg|200px]]
{{clade
| name=Rice, white, long-grain, regular, unenriched, cooked without salt
|label1=[[Poaceae]]
| Scientific Name = ''[[Oryza sativa]]''
|1={{clade
| water=68.44 g
|1=other grasses
| kcal=130
|2={{clade
| protein=2.69 g
|label1=[[PACMAD clade]]
| fat=0.28 g
|1=(inc. the [[C4 carbon fixation|C4 grasses]], [[maize]], [[sorghum]])
| carbs=28.1 g
|label2=[[BOP clade]]
| sugars=0.05 g
|2={{clade
| fiber=0.4 g
|label1=[[Oryzoideae]]
| iron_mg=0.2
|1={{clade
| manganese_mg=0
|1=[[Streptogyneae]]
| calcium_mg=10
|2={{clade
| magnesium_mg=12
|1=[[Ehrharteae]]
| phosphorus_mg=43
|2={{clade
| potassium_mg=35
|1=[[Phyllorachideae]]
| sodium_mg=1
|label2=[[Oryzeae]]
| zinc_mg=0.049
|2={{clade
| pantothenic_mg=0
|1=Wild rices inc. ''[[Zizania]]''
| vitB6_mg=0.093
|label2=''[[Oryza]]''
| folate_[[ug]]=0
|2={{clade
| thiamin_mg=0.02
|1=other rice species and subspecies
| riboflavin_mg=0.013
|2='''''[[Oryza sativa|O. sativa]]''''' (Asian rice)
| niacin_mg=0.4
|3='''''[[Oryza glaberrima|O. glaberrima]]''''' (African rice)
| note=[https://web.archive.org/web/20180915122210/https://ndb.nal.usda.gov/ndb/foods/show/20445 Link to USDA Database entry]
}}
| source_usda=1
}}
}}
}}
{{Nutritional value
}}
| name=Rice, white, short-grain, cooked
}}
|Scientific Name = ''[[Oryza sativa]]''
|2={{clade
| water=68.53 g
|1=[[Bambusoideae]] (bamboos)
| kJ=544
|2=[[Pooideae]] (grasses and cereals inc. [[wheat]], [[barley]])
| protein=2.36 g
}}
| fat=0.19 g
}}
| carbs=28.73 g
}}
| sugars=0 g
}}
| fiber=0 g
| vitB6 =0.059mg
| iron_mg=0.20| manganese_mg=0.4
| calcium_mg=1| magnesium_mg=8| phosphorus_mg=33
| potassium_mg=26
| zinc_mg=0.4| pantothenic_mg=0.4| vitB6_mg=0.164
| folate_[[ug]]=2
| thiamin_mg=0.02
| riboflavin_mg=0.016| niacin_mg=0.4
| note=[https://web.archive.org/web/20180915122224/https://ndb.nal.usda.gov/ndb/foods/show/20453 Link to USDA Database entry]
| source_usda=1
}}
}}


{{Anchor|Domestication}}
===Arsenic concerns===
{{Main|Arsenic poisoning}}


=== History ===
As arsenic occurs in soil, water, and air, the United States [[Food and Drug Administration]] (FDA) monitors the levels of arsenic in foods, particularly in rice products used commonly for infant food.<ref name="fda-ars">{{cite web|url=https://www.fda.gov/food/foodborneillnesscontaminants/metals/ucm319870.htm|title=Arsenic in Rice and Rice Products|publisher=US Food and Drug Administration|date=April 24, 2017|access-date=May 12, 2017|archive-url=https://web.archive.org/web/20170502180624/https://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm319870.htm|archive-date=May 2, 2017|url-status=live}}</ref> While growing, rice plants tend to absorb arsenic more readily than other food crops, requiring expanded testing by the FDA for possible arsenic-related risks associated with rice consumption in the United States.<ref name=fda-ars/> In April 2016, the FDA proposed a limit of 100 parts per billion (ppb) for inorganic arsenic in infant [[rice cereal]] and other foods to minimize exposure of infants to arsenic.<ref name=fda-ars/> For water contamination by arsenic, the United States [[Environmental Protection Agency]] has set a lower standard of 10 ppb.<ref name="epa">{{cite web|url=https://www.epa.gov/dwreginfo/chemical-contaminant-rules|title=Chemical Contaminant Rules|publisher=US Environmental Protection Agency|date=April 24, 2017|access-date=May 12, 2017|archive-url=https://web.archive.org/web/20170519033834/https://www.epa.gov/dwreginfo/chemical-contaminant-rules|archive-date=May 19, 2017|url-status=live}}</ref>


{{main |History of rice cultivation}}
Arsenic is a [[List of IARC Group 1 carcinogens|Group 1 carcinogen]].<ref name=fda-ars/><ref name=EFSA2009>{{cite journal|title=Scientific Opinion on Arsenic in Food|journal= [[EFSA Journal]] |date=October 28, 2009|volume=7|issue=10|page=1351|doi=10.2903/j.efsa.2009.1351|author=EFSA Panel on Contaminants in the Food Chain (CONTAM)|doi-access=free}}</ref> The amount of arsenic in rice varies widely with the greatest concentration in brown rice and rice grown on land formerly used to grow cotton, such as in [[Arkansas]], [[Louisiana]], [[Missouri]], and [[Texas]].<ref name=CR1112>{{cite news | title=Arsenic in your food: Our findings show a real need for federal standards for this toxin | url=http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm | access-date=March 13, 2014 | work= [[Consumer Reports]] | date=November 2012 | url-status=live | archive-date=March 8, 2014 | archive-url=https://web.archive.org/web/20140308144211/http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm}}</ref> White rice grown in Arkansas, Louisiana, Missouri, and Texas, which account collectively for 76 percent of American-produced rice, had higher levels of arsenic than other regions of the world studied, possibly because of past use of arsenic-based pesticides to control cotton weevils.<ref>{{cite web | url = http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm#chart | work = [[Consumer Reports Magazine]] | date = November 2012 | title = Arsenic in your Food | archive-url = https://web.archive.org/web/20140308144211/http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm#chart | archive-date=March 8, 2014}}</ref> Jasmine rice from Thailand and Basmati rice from Pakistan and India contain the least arsenic among rice varieties in one study.<ref name="cpotera">{{cite journal | vauthors = Potera C | title = U.S. rice serves up arsenic | journal = [[Environmental Health Perspectives]] | volume = 115 | issue = 6 | pages = A296 | date = June 2007 | pmid = 17589576 | pmc = 1892142 | doi = 10.1289/ehp.115-a296 }}</ref> China has set a limit of 150 ppb for arsenic in rice.<ref>{{cite web | url = http://medicalxpress.com/news/2011-12-rice-source-arsenic-exposure.html | title = Rice as a source of arsenic exposure] | archive-url = https://web.archive.org/web/20140110085539/http://medicalxpress.com/news/2011-12-rice-source-arsenic-exposure.html | archive-date= January 10, 2014 | work = Medicalxpress.com | date = December 5, 2011 }}</ref>{{ Unreliable source | date = May 2023 }}


[[File:KITLV_40091_-_Kassian_Céphas_-_Relief_of_the_hidden_base_of_Borobudur_-_1890-1891.jpg|thumb|upright=1.5|Bas-relief of 9th century [[Borobudur]] in Indonesia describes [[rice barn]]s and rice plants infested by mice.]]
===''Bacillus cereus''===
Cooked rice can contain ''[[Bacillus cereus]]'' spores, which produce an [[emetic]] toxin when left at {{convert|4|–|60|°C|°F}}. When storing cooked rice for use the next day, rapid cooling is advised to reduce the risk of toxin production.<ref>{{cite web|title=Can reheating rice cause food poisoning?|url=http://www.nhs.uk/chq/Pages/can-reheating-rice-cause-food-poisoning.aspx?CategoryID=51&SubCategoryID=215|work= [[National Health Service]] (England) NHS.uk|date=June 26, 2018|access-date=February 19, 2012|archive-url=https://web.archive.org/web/20130708044941/http://www.nhs.uk/chq/pages/can-reheating-rice-cause-food-poisoning.aspx?categoryid=51&subcategoryid=215|archive-date=July 8, 2013|url-status=live}}</ref> One of the [[enterotoxin]]s produced by ''Bacillus cereus'' is heat-resistant; reheating contaminated rice kills the bacteria, but does not destroy the toxin already present.


''[[Oryza sativa]]'' rice was first [[Domestication|domesticated]] in [[Neolithic China|China]] 9,000 years ago,<ref name="Fornasiero Wing Ronald 2022">{{cite journal |last1=Fornasiero |first1=Alice |last2=Wing |first2=Rod A. |last3=Ronald |first3=Pamela |title=Rice domestication |journal=Current Biology |date=January 2022 |volume=32 |issue=1 |pages=R20–R24 |doi=10.1016/j.cub.2021.11.025 |pmid=35015986 |bibcode=2022CBio...32..R20F }}</ref> by people of [[Neolithic]] cultures in the [[Upper Yangtze|Upper]] and [[Lower Yangtze]], associated with [[Hmong-Mien]]-speakers and [[pre-Austronesians]], respectively.<ref name="Bellwood2011">{{cite journal |last1=Bellwood |first1=Peter |title=The Checkered Prehistory of Rice Movement Southwards as a Domesticated Cereal—from the Yangzi to the Equator |journal=Rice |date=December 2011 |volume=4 |issue=3–4 |pages=93–103 |doi=10.1007/s12284-011-9068-9 |doi-access=free |bibcode=2011Rice....4...93B }}</ref><ref name="He2017">{{cite journal |last1=He |first1=Keyang |last2=Lu |first2=Houyuan |last3=Zhang |first3=Jianping |last4=Wang |first4=Can |last5=Huan |first5=Xiujia |title=Prehistoric evolution of the dualistic structure mixed rice and millet farming in China |journal=The Holocene |date=December 2017 |volume=27 |issue=12 |pages=1885–1898 |doi=10.1177/0959683617708455 }}</ref><ref name="Hsieh2011">{{cite journal |last1=Hsieh |first1=Jaw-shu |last2=Hsing |first2=Yue-ie Caroline |last3=Hsu |first3=Tze-fu |last4=Li |first4=Paul Jen-kuei |last5=Li |first5=Kuang-ti |last6=Tsang |first6=Cheng-hwa |date=December 24, 2011 |title=Studies on Ancient Rice—Where Botanists, Agronomists, Archeologists, Linguists, and Ethnologists Meet |journal=Rice |volume=4 |issue=3–4 |pages=178–183 |doi=10.1007/s12284-011-9075-x |doi-access=free |bibcode=2011Rice....4..178H }}</ref><ref name="Zhang2008">{{cite journal |last1=Chi |first1=Zhang |last2=Hung |first2=Hsiao-Chun |title=The Neolithic of Southern China—Origin, Development, and Dispersal |journal=Asian Perspectives |date=2008 |volume=47 |issue=2 |pages=299–329 |id={{Gale|A191316867}} {{Project MUSE|257900}} |jstor=42928744 |doi=10.1353/asi.0.0004 |hdl=10125/17291 |hdl-access=free }}</ref> The functional [[allele]] for [[Shattering (agriculture) |nonshattering]], the critical indicator of domestication in grains, as well as five other [[single-nucleotide polymorphism]]s, is identical in both ''indica'' and ''[[Japonica rice |japonica]]''. This implies a single domestication event for ''O. sativa''.<ref name="Vaughan Lu Tomooka 2008"/> Both ''indica'' and ''[[Japonica rice |japonica]]'' forms of Asian rice sprang from a single domestication event in China from the wild rice ''[[Oryza rufipogon]]''.<ref name="Molina Sikora Garud 2011">{{Cite journal |last1=Molina |first1=J. |last2=Sikora |first2=M. |last3=Garud |first3=N. |last4=Flowers |first4=J. M. |last5=Rubinstein |first5=S. |last6=Reynolds |first6=A. |last7=Huang |first7=P. |last8=Jackson |first8=S. |last9=Schaal |first9=B. A. |last10=Bustamante |first10=C. D. |last11=Boyko |first11=A. R. |display-authors=5 |year=2011 |title=Molecular evidence for a single evolutionary origin of domesticated rice |journal=[[Proceedings of the National Academy of Sciences of the United States of America|Proceedings of the National Academy of Sciences]] |volume=108 |issue=20 |pages=8351–8356 |bibcode=2011PNAS..108.8351M |doi=10.1073/pnas.1104686108 |pmc=3101000 |pmid=21536870 |last12=Purugganan |first12=M. D. |doi-access=free }}</ref><ref name="Vaughan Lu Tomooka 2008">{{cite journal |last1=Vaughan |first1=Duncan A. |last2=Lu |first2=Bao-Rong |last3=Tomooka |first3=Norihiko |title=The evolving story of rice evolution |journal=Plant Science |date=April 2008 |volume=174 |issue=4 |pages=394–408 |doi=10.1016/j.plantsci.2008.01.016 }}</ref> 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 ''[[Oryza nivara |O. nivara]]''.<ref name="Choi 2017">{{cite journal |last=Choi |first=Jae |display-authors=etal |year=2017 |title=The Rice Paradox: Multiple Origins but Single Domestication in Asian Rice |journal=[[Molecular Biology and Evolution]] |volume=34 |issue=4 |pages=969–979 |doi=10.1093/molbev/msx049 |pmc=5400379 |pmid=28087768}}</ref>
== Rice-growing environments ==
Rice growth and production are affected by: the environment, soil properties, biotic conditions, and cultural practices. Environmental factors include rainfall and water, temperature, photoperiod, solar radiation and, in some instances, tropical storms. Soil factors refer to soil type and their position in uplands or lowlands. Biotic factors deal with weeds, insects, diseases, and crop varieties.<ref>{{cite book | title = Soils, Plant Growth and Crop Production Volume II | chapter = Growth and Production of Rice | editor = Willy H. Verheye | date = 2010 | publisher = [[EOLSS]] Publishers | isbn = 978-1-84826-368-0 | url = https://www.eolss.net/ebooklib/bookinfo/soils-plant-growth-crop-production.aspx | page = 49 }}</ref>
Rice can be grown in different environments, depending upon water availability.<ref>{{cite web | url = http://www.knowledgebank.irri.org/ | title = IRRI Rice Knowledge Bank | archive-url = https://web.archive.org/web/20040522064816/http://www.knowledgebank.irri.org/ | archive-date=May 22, 2004 | work = [[IRRI Rice Knowledge Bank]] (International Rice Research Institute) | access-date = April 20, 2013 }}</ref> Generally, rice does not thrive in a waterlogged area, yet it can survive and grow herein<ref>{{cite web | url = http://ciifad.cornell.edu/sri/extmats/philmanual.pdf | title = More rice with less water | archive-url = https://web.archive.org/web/20111226111455/https://ciifad.cornell.edu/sri/extmats/philmanual.pdf | archive-date= December 26, 2011 | work = [[Cornell University]] | access-date = May 13, 2012 }}</ref> and it can survive flooding.<ref>{{cite web | url = http://www.uu.nl/EN/Current/Pages/Gewaarschuwdeplantenhoudenademinbijoverstroming.aspx | title = Plants capable of surviving flooding | archive-url = https://web.archive.org/web/20140331130734/http://www.uu.nl/EN/Current/Pages/Gewaarschuwdeplantenhoudenademinbijoverstroming.aspx | archive-date = March 31, 2014 | work = Uu.nl | access-date = May 13, 2012 }}</ref>


Rice was introduced early into [[Sino-Tibetan]] cultures in northern China by around 6000 to 5600 years ago,<ref name="Zhang2012">{{cite journal |last1=Zhang |first1=Jianping |last2=Lu |first2=Houyuan |last3=Gu |first3=Wanfa |last4=Wu |first4=Naiqin |last5=Zhou |first5=Kunshu |last6=Hu |first6=Yayi |last7=Xin |first7=Yingjun |last8=Wang |first8=Can |last9=Kashkush |first9=Khalil |display-authors=5 |date=December 17, 2012 |title=Early Mixed Farming of Millet and Rice 7800 Years Ago in the Middle Yellow River Region, China |journal=PLOS ONE |volume=7 |issue=12 |pages=e52146 |bibcode=2012PLoSO...752146Z |doi=10.1371/journal.pone.0052146 |pmc=3524165 |pmid=23284907 |doi-access=free }}</ref><ref name="Fuller2011">{{cite journal |last1=Fuller |first1=Dorian Q. |title=Pathways to Asian Civilizations: Tracing the Origins and Spread of Rice and Rice Cultures |journal=Rice |date=December 2011 |volume=4 |issue=3–4 |pages=78–92 |doi=10.1007/s12284-011-9078-7 |doi-access=free |bibcode=2011Rice....4...78F }}</ref><ref name="He2017"/> and to the [[Korea]]n peninsula and [[Japan]] by around 5500 to 3200 years ago.<ref name="Crawford and Shen 1998">{{cite journal |last1=Crawford |last2=Shen |year=1998 |title=The Origins of rice agriculture: recent progress in East Asia |journal=Antiquity |volume=72 |issue=278 |pages=858–866 |doi=10.1017/S0003598X00087494 |s2cid=162486123 }}</ref><ref>{{cite journal |last1=Crawford |first1=G. W. |last2=Lee |first2=G.-A. |date=March 2003 |title=Agricultural Origins in the Korean Peninsula |journal=Antiquity |volume=77 |issue=295 |pages=87–95 |doi=10.1017/s0003598x00061378 |s2cid=163060564 |name-list-style=amp}}</ref> It was also carried into [[Taiwan]] by the [[Dapenkeng]] culture by 5500 to 4000 years ago, before spreading southwards via the [[Austronesian expansion |Austronesian migrations]] to [[Island Southeast Asia]], [[Madagascar]], and [[Guam]], but did not survive the voyage to the rest of the Pacific.<ref name="Bellwood2011"/><ref name="Beaujard2011">{{cite journal |last1=Beaujard |first1=Philippe |title=The first migrants to Madagascar and their introduction of plants: linguistic and ethnological evidence |journal=Azania: Archaeological Research in Africa |date=August 2011 |volume=46 |issue=2 |pages=169–189 |doi=10.1080/0067270X.2011.580142 |url=https://halshs.archives-ouvertes.fr/halshs-00706173/file/Beaujard.azania2.pdf }}</ref><ref name="Carson2012">{{cite journal |last1=Carson |first1=Mike T. |date=2012 |title=An overview of latte period archaeology |url=https://micronesica.org/sites/default/files/1_carson1-79sm.pdf |url-status=live |journal=Micronesica |volume=42 |issue=1/2 |pages=1–79 |archive-url=https://web.archive.org/web/20190412090641/https://micronesica.org/sites/default/files/1_carson1-79sm.pdf |archive-date=April 12, 2019 |access-date=January 25, 2019}}</ref> It reached [[Austroasiatic]] and [[Kra-Dai]]-speakers in [[Mainland Southeast Asia]] and southern China by 5000 years ago.<ref name="Bellwood2011" /><ref name="Higham2015">{{cite journal |last1=Higham |first1=Charles F. W. |last2=Douka |first2=Katerina |last3=Higham |first3=Thomas F. G. |last4=Hart |first4=John P. |date=September 18, 2015 |title=A New Chronology for the Bronze Age of Northeastern Thailand and Its Implications for Southeast Asian Prehistory |journal=PLOS ONE |volume=10 |issue=9 |pages=e0137542 |bibcode=2015PLoSO..1037542H |doi=10.1371/journal.pone.0137542 |pmc=4575132 |pmid=26384011 |doi-access=free }}</ref>
# Lowland, rainfed, which is drought prone, favors medium depth; waterlogged, submergence, and flood prone
# Lowland, irrigated, grown in both the wet season and the dry season
# [[Deep water rice|Deep water]] or floating rice
# Coastal wetland
# [[Upland rice]] (also known as hill rice or Ghaiya rice)


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.<ref name="Choi 2019"/> The now less common ''[[Oryza glaberrima]]'' (African rice) was independently domesticated in Africa around 3,000 years ago,<ref name="Choi 2019">{{Cite journal |last=Choi |first=Jae Young |date=March 7, 2019 |title=The complex geography of domestication of the African rice Oryza glaberrima |journal=PLOS Genetics |volume=15 |issue=3 |pages=e1007414 |doi=10.1371/journal.pgen.1007414 |pmc=6424484 |pmid=30845217 |doi-access=free }}</ref> and introduced to the Americas by the Spanish.<ref name="National Academies Press 1996">{{cite book |author=National Research Council |url=http://books.nap.edu/openbook.php?record_id=2305 |title=Lost Crops of Africa: Volume I: Grains |publisher=[[National Academies Press]] |year=1996 |isbn=978-0-309-04990-0 |volume=1 |chapter=African Rice |doi=10.17226/2305 |access-date=July 18, 2008 |chapter-url=http://books.nap.edu/openbook.php?record_id=2305&page=17 |archive-url=https://web.archive.org/web/20090122104044/http://books.nap.edu/openbook.php?record_id=2305 |archive-date=January 22, 2009 |url-status=live}}</ref> 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.<ref>{{Cite journal |last=Morgan |first=Kenneth |date=July 1995 |title=The Organization of the Colonial American Rice Trade |journal=[[The William and Mary Quarterly]] |volume=52 |issue=3 |pages=433–452 |doi=10.2307/2947294 |jstor=2947294 }}</ref>
{{ Anchor | Domestication }}
== History of cultivation ==
{{ Excerpt | History_of_rice_cultivation }}


== Production and commerce ==
== Commerce ==

{| class="wikitable" style="float:right; clear:left; width:19em; margin-left:1ex;"
{| class="wikitable" style="float:right; clear:right; width:14em; text-align:center; margin-right:1em;"
! colspan=2|Rice production – 2020
! colspan=2|Rice production – 2021
|-
|-
! style="background:#ddf; width:50%;"| Country
! style="background:#ddf; width:50%;"|Country
! style="background:#ddf; width:50%;"| <small> Millions of [[tonne]]s </small>
! style="background:#ddf; width:50%;"|<small> Millions of [[tonne]]s </small>
|-
|-
| {{CHN}} ||style="text-align: center;" | 211.9
|{{CHN}} ||[[Rice production in China|213]]
|-
|-
| {{IND}} ||style="text-align: center;" | 178.3
|{{IND}} ||[[Rice production in India|195]]
|-
|-
| {{BGD}} ||style="text-align: center;" | 54.9
|{{BGD}} ||[[Rice production in Bangladesh|57]]
|-
|-
| {{IDN}} ||style="text-align: center;" | 54.6
|{{IDN}} ||[[Rice production in Indonesia|54]]
|-
|-
| {{VNM}} ||style="text-align: center;" | 42.8
|{{VNM}} ||[[Rice production in Vietnam|44]]
|-
|-
| {{THA}} ||style="text-align: center;" | 30.2
|{{THA}} ||[[Rice production in Thailand|30]]
|-
|-
|'''World''' ||'''787'''<ref name="faostat">{{cite web |url=http://www.fao.org/faostat/en/#data/QC |title=Rice production in 2021; Crops/Regions/World list/Production Quantity/Year (from pick lists) |date=2023 |publisher=[[FAOSTAT]], UN Food and Agriculture Organization, Corporate Statistical Database |access-date=December 4, 2023}}</ref>
| {{MYA}} ||style="text-align: center;" | 25.1
|-
| {{PHI}} ||style="text-align: center;" | 19.3
|-
| {{BRA}} ||style="text-align: center;" | 11.1
|-
| {{KHM}} ||style="text-align: center;" | 11.0
|-
|style="text-align: center;" | '''World''' ||style="text-align: center;" | '''756.7'''
|-
|colspan=2 style="text-align: center;" |<small>Source: [[FAOSTAT]] of the United Nations<ref name="faostat19">{{cite web|url=http://www.fao.org/faostat/en/#data/QC|title=Crops/Regions/World list/Production Quantity (pick lists), Rice (paddy), 2019|date=2021 | publisher= [[FAOSTAT]] (UN Food and Agriculture Organization, Corporate Statistical Database) |access-date=May 7, 2021}}</ref></small>
|}
|}


=== Production ===
=== Production ===
{{ See also | List of countries by rice production }}
[[File:RiceYield.png|thumb|Worldwide rice production]]
In 2020, world production of paddy rice was {{convert|756.7|e6MT|e6ST|abbr=off}},<ref>{{Cite web |url=http://www.fao.org/faostat/en/#data/QC |title=Faostat |access-date=May 11, 2017 |archive-url=https://web.archive.org/web/20170511194947/http://www.fao.org/faostat/en/#data/QC |archive-date=May 11, 2017 |url-status=live | publisher= [[FAOSTAT]] (UN Food and Agriculture Organization, Corporate Statistical Database) }}</ref> led by China and India with a combined 52% of this total.<ref name=faostat16/> Other major producers were [[Bangladesh]], [[Indonesia]] and [[Vietnam]]. The five major producers accounted for 72% of total production, while the top fifteen producers accounted for 91% of total world production in 2017 (see table on right). Developing countries account for 95% of the total production.<ref name=FAORice1/>
[[File:Production of rice (2019).svg|thumb|Production of rice (2019)<ref>{{Cite book|title=World Food and Agriculture – Statistical Yearbook 2021|url=https://www.fao.org/documents/card/en/c/cb4477en/|access-date=December 10, 2021|publisher= United Nations [[Food and Agriculture Organization]] (FAO) |year=2021|language=en|doi=10.4060/cb4477en|isbn=978-92-5-134332-6|s2cid=240163091}}</ref>]]
Rice is a major food staple and a mainstay for the rural population and their food security. It is mainly cultivated by small farmers in holdings of less than one [[hectare]]. Rice is also a wage commodity for workers in the cash crop or non-agricultural sectors. Rice is vital for the nutrition of much of the population in Asia, as well as in Latin America and the Caribbean and in Africa; it is central to the food security of over half the world population.


{{ See also |List of countries by rice production }}
Many rice grain producing countries have significant losses post-harvest at the farm and because of poor roads, inadequate storage technologies, inefficient supply chains and farmer's inability to bring the produce into retail markets dominated by small shopkeepers. A World Bank – FAO study claims 8% to 26% of rice is lost in developing nations, on average, every year, because of post-harvest problems and poor infrastructure. Some sources claim the post-harvest losses exceed 40%.<ref name=FAORice1>{{cite web|title=Sustainable rice production for food security|publisher=United Nations [[Food and Agriculture Organization]] (FAO)|year=2003|url=http://www.fao.org/docrep/006/Y4751E/y4751e00.htm|access-date=March 14, 2014|archive-url=https://web.archive.org/web/20140615103824/http://www.fao.org/docrep/006/y4751e/y4751e00.HTM|archive-date=June 15, 2014|url-status=live}}</ref><ref>{{cite web|title=MISSING FOOD: The Case of Postharvest Grain Losses in Sub-Saharan Africa|publisher= The [[World Bank]] |date=April 2011|url=http://siteresources.worldbank.org/INTARD/Resources/MissingFoods10_web.pdf|access-date=November 28, 2011|archive-url=https://web.archive.org/web/20111123194850/http://siteresources.worldbank.org/INTARD/Resources/MissingFoods10_web.pdf|archive-date=November 23, 2011|url-status=live}}</ref> Not only do these losses reduce food security in the world, the study claims that farmers in developing countries such as China, India and others lose approximately US$89 billion of income in preventable post-harvest farm losses, poor transport, the lack of proper storage and retail. One study claims that if these post-harvest grain losses could be eliminated with better infrastructure and retail network, in India alone enough food would be saved every year to feed 70 to 100 million people.<ref>{{cite journal | vauthors = Basavaraja H, Mahajanashetti SB, Udagatti NC |date=2007 |title=Economic Analysis of Post-harvest Losses in Food Grains in India: A Case Study of Karnataka |journal= [[Agricultural Economics Research Review]] |volume=20 |pages=117–26 |url=http://ageconsearch.umn.edu/bitstream/47429/2/8.pdf |access-date=November 27, 2011 |archive-url=https://web.archive.org/web/20120222212752/http://ageconsearch.umn.edu/bitstream/47429/2/8.pdf |archive-date=February 22, 2012 |url-status=live}}</ref>


In 2021, world production of rice was 787 million [[tonne]]s, led by China and India with a combined 52% of the total.<ref name="faostat"/> This placed rice fourth in the list of crops by production, after [[sugarcane]], [[maize]], and [[wheat]].<ref name="FAO production stats 2021"/> Other major producers were [[Bangladesh]], [[Indonesia]] and [[Vietnam]].<ref name="FAO production stats 2021"/> 90% of world production is from Asia.<ref name="Fukagawa Ziska 2019 pp. S2–S3"/>
<!-- This section is linked from [[Polished rice]] -->=== Processing ===
[[File:Rice Animation.gif|thumb|-[[Rice#Processing|Rice processing]]-<br> A: Rice with [[chaff]]<br>B: [[Brown rice]]<br>C: Rice with [[Cereal germ|germ]]<br>D: [[White rice]] with [[bran]] [[Crop residue|residue]]<br>E: Musenmai (Japanese: [[Musenmai|無洗米]]), "Polished and ready to boil rice", literally, non-wash rice<br>(1): [[Chaff]]<br>(2): [[Bran]]<br>(3): Bran [[Crop residue|residue]]<br>(4): [[Cereal germ]]<br>(5): [[Endosperm]]]] [[File:Stages of rice milling.jpg|thumb|Unmilled to milled [[Japanese rice]], from left to right, [[brown rice]], rice with [[Cereal germ|germ]], [[white rice]]]]


<gallery class="center" mode="nolines" heights="300" widths="450">
The seeds of the rice plant are first milled using a [[rice huller]] to remove the [[chaff]] (the outer husks of the grain) (see: [[rice hulls]]). At this point in the process, the product is called [[brown rice]]. The milling may be continued, removing the [[bran]], ''i.e.'', the rest of the husk and the [[cereal germ|germ]], thereby creating [[white rice]]. White rice, which keeps longer, lacks some important nutrients; moreover, in a limited diet which does not supplement the rice, brown rice helps to prevent the disease [[beriberi]].
File:Production of rice (2019).svg|Production of rice (2021)<ref name="FAO production stats 2021">{{cite book |title=World Food and Agriculture – Statistical Yearbook 2021 |url=https://www.fao.org/documents/card/en/c/cb4477en/ |access-date=December 10, 2021 |publisher=United Nations [[Food and Agriculture Organization]] |year=2021 |doi=10.4060/cb4477en |isbn=978-92-5-134332-6 |s2cid=240163091}}</ref>
File:World Production Of Primary Crops, Main Commodities.svg|Since 2000, rice production (orange) has increased,<br/>but its share of total crop production has fallen.
</gallery>


=== Yield records ===
Either by hand or in a [[rice polisher]], white rice may be buffed with glucose or [[talc]] powder (often called polished rice, though this term may also refer to white rice in general), [[parboiled rice|parboiled]], or processed into flour. 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.


The average world yield for rice was {{convert|4.7|MT/ha|ST/acre|abbr=off}}, in 2022.<ref>{{cite web |title=FAOSTAT: Production-Crops, 2022 data |publisher=United Nations [[Food and Agriculture Organization]] |year=2022 |url=http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567#ancor |access-date=January 12, 2012 |archive-date=June 19, 2012 |archive-url=https://web.archive.org/web/20120619130038/http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567#ancor |url-status=dead }}</ref> [[Yuan Longping]] of China's National Hybrid Rice Research and Development Center set a world record for rice yield in 1999<!--do not change this, it was a record at the time, see source--> at {{convert|17.1<!--historic record, top page of Yuan 2010-->|MT/ha|ST/acre|abbr=off}} on a demonstration plot. This employed specially developed hybrid rice and the [[System of Rice Intensification]] (SRI), an innovation in rice farming.<ref>{{cite web |title=A Scientist's Perspective on Experience with SRI in China for Raising the Yields of Super Hybrid Rice |year=2010 |last=Yuan |first=Longping |author-link=Yuan Longping |publisher=[[Cornell University]] |url=http://ciifad.cornell.edu/sri/proc1/sri_06.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111120010557/http://ciifad.cornell.edu/sri/proc1/sri_06.pdf |archive-date=November 20, 2011}}</ref>
In some countries, a popular form, [[parboiled rice]] (also known as '''converted rice''' and '''easy-cook rice'''<ref>{{Cite web | url=http://www.riceassociation.org.uk/content/1/10/varieties.html | title=Types of rice | publisher= [[Rice Association]] | access-date=August 2, 2018 | archive-url=https://web.archive.org/web/20180802162740/http://www.riceassociation.org.uk/content/1/10/varieties.html | archive-date=August 2, 2018 | url-status=live}}</ref>) is subjected to a steaming or [[parboiling]] process while still a brown rice grain. The parboil process causes a gelatinisation of the starch in the grains. The grains become less brittle, and the color of the milled grain changes from white to yellow. The rice is then dried, and can then be milled as usual or used as brown rice. Milled parboiled rice is nutritionally superior to standard milled rice, because the process causes nutrients from the outer husk (especially [[thiamine]]) to move into the [[endosperm]], so that less is subsequently lost when the husk is polished off during milling. Parboiled rice has an additional benefit in that it does not stick to the pan during cooking, as happens when cooking regular white rice. This type of rice is eaten in parts of India and countries of West Africa are also accustomed to consuming parboiled rice.


=== Food security ===
[[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 oil. It is also used as a pickling bed in making [[Nukazuke|rice bran pickles]] and ''[[takuan]]''.


Rice is a major food staple in Asia, Latin America, and some parts of Africa,<ref name="Nat Geog Food Staple">{{cite web |title=Food Staple |url=https://education.nationalgeographic.org/resource/food-staple/ |publisher=[[National Geographic]] Education |access-date=December 6, 2023}}</ref> feeding over half the world's population.<ref name="Fukagawa Ziska 2019 pp. S2–S3">{{cite journal |last1=Fukagawa |first1=Naomi K. |last2=Ziska |first2=Lewis H. |title=Rice: Importance for Global Nutrition |journal=Journal of Nutritional Science and Vitaminology |volume=65 |issue=Supplement |date=October 11, 2019 |doi=10.3177/jnsv.65.S2 |pages=S2–S3 |pmid=31619630 |doi-access=free }}</ref> 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 [[Mold|mould]] fungi if the rice is not dried sufficiently. In China, losses in modern metal [[silo]]s were just 0.2%, compared to 7–13% when rice was stored by rural households.<ref name="Kumar Kalita 2017">{{cite journal |last1=Kumar |first1=Deepak |last2=Kalita |first2=Prasanta |title=Reducing Postharvest Losses during Storage of Grain Crops to Strengthen Food Security in Developing Countries |journal=Foods |volume=6 |issue=1 |date=January 15, 2017 |pmid=28231087 |pmc=5296677 |doi=10.3390/foods6010008 |doi-access=free |page=8}}</ref>
Raw rice may be ground into flour for many uses, including making many kinds of beverages, such as ''[[amazake]], [[horchata]]'', [[rice milk]], and [[rice wine]]. Rice does not contain [[gluten]], so is suitable for people on a [[gluten-free diet]].<ref name="PenaginiDilillo2013">{{cite journal | vauthors = Penagini F, Dilillo D, Meneghin F, Mameli C, Fabiano V, Zuccotti GV | title = Gluten-free diet in children: an approach to a nutritionally adequate and balanced diet | journal = [[Nutrients (journal)|Nutrients]] | volume = 5 | issue = 11 | pages = 4553–4565 | date = November 2013 | pmid = 24253052 | pmc = 3847748 | doi = 10.3390/nu5114553 | type = Review | doi-access = free }}</ref> Rice can be made into various types of [[noodle]]s. Raw, wild, or brown rice may also be consumed by [[Raw foodism|raw-foodist]] or [[fruitarians]] if soaked and [[Sprouting|sprouted]] (usually a week to 30 days – gaba rice).


=== Processing === <!-- This section is linked from [[Polished rice]] -->
Processed rice seeds must be boiled or steamed before eating. Boiled rice may be further fried in [[cooking oil]] or butter (known as [[fried rice]]), or beaten in a tub to make ''[[mochi]]''.
{|class="wikitable floatright" style="font-size:85%;text-align:left;width:25em;"
|-style="text-align:center;"
| colspan=2 | [[File:Rice Animation.gif|frameless|upright=1.15|alt=Five-step animation showing the removal of successive layers from raw rice grains, starting with the grain with its inedible hull and ending with polished white rice.]]<br/>[[#Processing|Rice processing]] removes one or more layers to create marketable products.
|-
|<ol style="list-style-type:upper-alpha;">
<li>Rice with [[chaff]]</li>
<li>[[Brown rice]]</li>
<li>Rice with [[Cereal germ|germ]]</li>
<li>[[White rice]] with [[bran]] [[Crop residue|residue]]</li>
<li>Polished</li>
</ol>
|<ol>
<li>[[Chaff]]</li>
<li>[[Bran]]</li>
<li>Bran [[Crop residue|residue]]</li>
<li>[[Cereal germ]]</li>
<li>[[Endosperm]]</li>
</ol>
|}


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.<ref name="IRRI Milling">{{cite web |title=Milling |url=http://www.knowledgebank.irri.org/step-by-step-production/postharvest/milling |publisher=[[International Rice Research Institute]] |access-date=January 4, 2024}}</ref> Brown rice only has the inedible husk removed.<ref name="RA varieties"/> Further milling removes bran and the germ to create successively whiter products.<ref name="RA varieties"/> [[Parboiled rice]] is subjected to a steaming process before it is milled. This makes the grain harder, and moves some of the grain's [[vitamin]]s and [[Mineral (nutrient)|minerals]] into the white part of the rice so these are retained after milling.<ref name="RA varieties">{{cite web |title=Types of rice |publisher=Rice Association |url=http://www.riceassociation.org.uk/content/1/10/varieties.html |access-date=August 2, 2018 |archive-url=https://web.archive.org/web/20180802162740/http://www.riceassociation.org.uk/content/1/10/varieties.html |archive-date=August 2, 2018 |url-status=dead}}</ref> Rice does not contain [[gluten]], so is suitable for people on a [[gluten-free diet]].<ref name="Penagini Dilillo Meneghin Mameli 2013">{{cite journal |last1=Penagini |first1=Francesca |last2=Dilillo |first2=Dario |last3=Meneghin |first3=Fabio |last4=Mameli |first4=Chiara |last5=Fabiano |first5=Valentina |last6=Zuccotti |first6=Gian |title=Gluten-Free Diet in Children: An Approach to a Nutritionally Adequate and Balanced Diet |journal=Nutrients |publisher=[[MDPI|MDPI AG]] |volume=5 |issue=11 |date=November 18, 2013 |doi=10.3390/nu5114553 |pages=4553–4565 |pmid=24253052 |pmc=3847748 |doi-access=free }}</ref> 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 the [[essential amino acids]] in sufficient amounts for good health.<ref name="Wu Shi Zhang 2002">{{cite journal |last1=Wu |first1=Jianguo G. |last2=Shi |first2=Chunhai |last3=Zhang |first3=Xiaoming |title=Estimating the amino acid composition in milled rice by near-infrared reflectance spectroscopy |journal=Field Crops Research |date=March 2002 |volume=75 |issue=1 |pages=1–7 |doi=10.1016/s0378-4290(02)00006-0 |bibcode=2002FCrRe..75....1W }}</ref>
Rice is a good source of protein and a staple food in many parts of the world, but it is not a [[complete protein]]: it does not contain all of the [[essential amino acids]] in sufficient amounts for good health, and should be combined with other sources of protein, such as nuts, seeds, beans, fish, or meat.<ref name="Protein content">{{cite journal|doi=10.1016/S0378-4290(02)00006-0 | title=Estimating the amino acid composition in milled rice by near-infrared reflectance spectroscopy | vauthors = Wu JG, Shi C, Zhang X | year=2003|journal= [[Field Crops Research]] |volume=75|page=1}}</ref>


<gallery mode=packed heights=150>
Rice, like other cereal [[caryopsis|grains]], can be [[Puffed rice|puffed (or popped)]]. This process takes advantage of the grains' water content and typically involves heating grains in a special chamber. Further puffing is sometimes accomplished by processing puffed pellets in a low-[[pressure]] chamber. The [[ideal gas law]] means 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 (food)|texture]]. Bulk raw rice density is about 0.9 g/cm<sup>3</sup>. It decreases to less than one-tenth that when puffed.
File:Stages of rice milling.jpg|Unmilled to milled [[Japanese rice]], from left to right, [[brown rice]], rice with [[Cereal germ|germ]], [[white rice]]
</gallery>


=== Harvesting, drying and milling ===
=== Trade ===
[[File:Rice-combine-harvester, Katori-city, Japan.jpg|thumb|Rice combine harvester in [[Katori, Chiba|Katori]], [[Chiba Prefecture]], [[Japan]]]]
[[File:Rice farmers Mae Wang Chiang Mai Province.jpg|thumb|After the harvest, rice straw is gathered in the traditional way from small paddy fields in [[Mae Wang District]], Thailand]]
{{ Further | Paddy field }}
<!-- [[Paddy]] and [[Padi]] link to this section -->
Unmilled rice, known as "paddy" (Indonesia and Malaysia: padi; Philippines, palay), is usually harvested when the grains have a moisture content of around 25%. In most Asian countries, where rice is almost entirely the product of [[smallholder]] agriculture, harvesting is carried out manually, although there is a growing interest in mechanical harvesting. Harvesting can be carried out by the farmers themselves, but is also frequently done by seasonal labor groups. Harvesting is followed by [[threshing]], either immediately or within a day or two. Again, much threshing is still carried out by hand but there is an increasing use of mechanical threshers. Subsequently, paddy needs to be dried to bring down the moisture content to no more than 20% for milling.[[File:NP India burning 48 (6315309342).jpg|thumb|Burning of rice residues after harvest, to quickly prepare the land for [[wheat]] planting, around [[Sangrur]], India]]


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.<ref name="Cendrowski 2013">{{cite web |last=Cendrowski |first=Scott |date=July 25, 2013 |title=The Rice Rush |website=Fortune |url=https://fortune.com/2013/07/25/the-rice-rush/ |access-date=January 4, 2024}}</ref> Developing countries are the main players in the world rice trade; by 2012, India was the largest exporter of rice, with Thailand and Vietnam the other largest exporters.<ref>{{cite news |url=http://blogs.ft.com/beyond-brics/2012/10/30/india-and-the-price-of-rice/#axzz2d3SGzLpN |last=Chilkoti |first=A. |title=India and the Price of Rice |newspaper=[[Financial Times]] |location=London |date=October 30, 2012 |archive-url=https://web.archive.org/web/20130120052047/http://blogs.ft.com/beyond-brics/2012/10/30/india-and-the-price-of-rice/#axzz2d3SGzLpN |archive-date=January 20, 2013 }}</ref>
A familiar sight in several Asian countries is paddy laid out to dry along roads. However, in most countries the bulk of drying of marketed paddy takes place in mills, with village-level drying being used for paddy to be consumed by farm families. Mills either sun dry or use mechanical driers or both. Drying has to be carried out quickly to avoid the formation of molds. Mills range from simple [[Rice huller|hullers]], with a throughput of a couple of tonnes a day, that simply remove the outer husk, to enormous operations that can process {{convert|4|e3MT|e3ST|abbr=off}} a day and produce highly polished rice. A good mill can achieve a paddy-to-rice conversion rate of up to 72% but smaller, inefficient mills often struggle to achieve 60%. These smaller mills often do not buy paddy and sell rice but only service farmers who want to mill their paddy for their own consumption.


=== Distribution ===
=== Worldwide consumption ===
Because of the importance of rice to human nutrition and food security in Asia, the domestic rice markets tend to be subject to considerable state involvement. While the private sector plays a leading role in most countries, agencies such as [[Indonesian Bureau of Logistics|BULOG]] in Indonesia, the [[National Food Authority (Philippines)|NFA]] in the Philippines, VINAFOOD in Vietnam and the [[Food Corporation of India]] are all heavily involved in purchasing of paddy from farmers or rice from mills and in distributing rice to poorer people. BULOG and NFA monopolise rice imports into their countries while VINAFOOD controls all exports from Vietnam.<ref>Shahidur Rashid, Ashok Gulari and Ralph Cummings Jnr (eds) (2008). ''From Parastatals to Private Trade''. International Food Policy Research Institute and Johns Hopkins University Press, {{ISBN|0-8018-8815-8}}</ref>


As of 2016, the countries that consumed the most rice were China (29% of total), India, and Indonesia.<ref name="Grain Central">{{cite web |title=Global rice consumption continues to grow |url=https://www.graincentral.com/cropping/global-rice-consumption-continues-to-grow/ |publisher=Grain Central |access-date=December 5, 2023 |date=March 26, 2018}}</ref> 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 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.<ref name="usda">{{cite web |title=Rice Sector at a Glance |url=https://www.ers.usda.gov/topics/crops/rice/rice-sector-at-a-glance/#Global |publisher=Economic Research Service, [[US Department of Agriculture]] |access-date=December 5, 2023 |date=September 27, 2023}}</ref>
[[File:Nellu.JPG|thumbnail|Drying rice in [[Peravoor]], India]]


===Trade===
== Food ==
World trade figures are very different from those for production, as less than 8% of rice produced is traded internationally.<ref name=cendrowski2013>{{cite journal | vauthors = Cendrowski S |date=August 12, 2013 |title=The Rice Rush |journal=[[Forbes (magazine)|Forbes]] |pages=9–10 |type=paper}}</ref> In economic terms, the global rice trade was a small fraction of 1% of world mercantile trade. Many countries consider rice as a strategic food staple, and various governments subject its trade to a wide range of controls and interventions.


{{Infobox nutritional value
Developing countries are the main players in the world rice trade, accounting for 83% of exports and 85% of imports. While there are numerous importers of rice, the exporters of rice are limited. Just five countries—Thailand, Vietnam, China, the United States and India—in decreasing order of exported quantities, accounted for about three-quarters of world rice exports in 2002.<ref name=FAORice1/> However, this ranking has been rapidly changing in recent years. In 2010, the three largest exporters of rice, in decreasing order of quantity exported were Thailand, Vietnam and India. By 2012, India became the largest exporter of rice with a 100% increase in its exports on year-to-year basis, and Thailand slipped to third position.<ref>{{cite web | url = http://blogs.ft.com/beyond-brics/2012/10/30/india-and-the-price-of-rice/#axzz2d3SGzLpN | vauthors = Chilkoti A | title = India and the Price of Rice | work = The [[Financial Times]] | location = London | date = October 30, 2012 | archive-url = https://web.archive.org/web/20130120052047/http://blogs.ft.com/beyond-brics/2012/10/30/india-and-the-price-of-rice/#axzz2d3SGzLpN | archive-date = January 20, 2013 }}</ref><ref>{{cite web | url = http://www.ers.usda.gov/media/928481/rcs-12j.pdf | title = Rice Outlook 2012/2013 | archive-url = https://web.archive.org/web/20130620115109/http://www.ers.usda.gov/media/928481/rcs-12j.pdf | archive-date=June 20, 2013 | vauthors = Childs N | work = [[US Dept of Agriculture]] }}</ref> Together, Thailand, Vietnam and India accounted for nearly 70% of the world rice exports.
| name=Cooked white rice, medium-grain, unenriched
| water=69 g
| kJ=544
| protein=2.4 g
| fat=0.2 g
| carbs=28.6 g
| calcium_mg=3
| iron_mg=0.2
| magnesium_mg=13
| phosphorus_mg=37
| potassium_mg=29
| sodium_mg=0
| zinc_mg=0.4
| manganese_mg=0.38
| thiamin_mg=0.02
| riboflavin_mg=0.02
| niacin_mg=0.4
| pantothenic_mg=0.41
| vitB6_mg=0.05
| folate_ug=2
| note=[https://fdc.nal.usda.gov/fdc-app.html#/food-details/168930/nutrients FoodData Central entry]}}


{{main|Rice as food}}
The primary variety exported by Thailand and Vietnam were [[Jasmine rice]], while exports from India included aromatic [[Basmati]] variety. China, an exporter of rice in early 2000s, was a net importer of rice in 2010 and will become the largest net importer, surpassing Nigeria, in 2013.{{Needs update|date=January 2023}}<ref name=cendrowski2013/><ref>{{cite web |title=World Rice Trade |date=November 2011 |publisher= [[United States Department of Agriculture]] (USDA) |url=http://apps.fas.usda.gov/psdonline/psdreport.aspx?hidReportRetrievalName=BVS&hidReportRetrievalID=677&hidReportRetrievalTemplateID=7 |access-date=March 14, 2014 |archive-url=https://web.archive.org/web/20140110212246/http://apps.fas.usda.gov/psdonline/psdreport.aspx?hidReportRetrievalName=BVS&hidReportRetrievalID=677&hidReportRetrievalTemplateID=7 |archive-date=January 10, 2014 |url-status=dead}}</ref> According to a [[United States Department of Agriculture|USDA]] report, the world's largest exporters of rice in 2012 were India ({{convert|9.75|e6MT|e6ST|abbr=off}}), Vietnam ({{convert|7|e6MT|e6ST|abbr=off}}), Thailand ({{convert|6.5|e6MT|e6ST|abbr=off}}), Pakistan ({{convert|3.75|e6MT|e6ST|abbr=off}}) and the United States ({{convert|3.5|e6MT|e6ST|abbr=off}}).<ref>{{cite web | url = http://www.financialexpress.com/news/india-is-worlds-largest-rice-exporter-usda/1023491/0 | title = India is world's largest rice exporter: USDA | archive-url = https://web.archive.org/web/20130514233220/http://www.financialexpress.com/news/india-is-worlds-largest-rice-exporter-usda/1023491/0 | archive-date= May 14, 2013 | work = The [[The Financial Express (India)|Financial Express]] | date = October 29, 2012 }}</ref>


=== Eating qualities ===
Major importers usually include Nigeria, Indonesia, Bangladesh, Saudi Arabia, Iran, Iraq, Malaysia, the Philippines, Brazil and some African and [[Persian Gulf]] countries. In common with other West African countries, Nigeria is actively promoting domestic production. However, its very heavy import duties (110%) open it to smuggling from neighboring countries.<ref>{{cite web | work = [[Agritrade]] | url = http://agritrade.cta.int/Agriculture/Commodities/Rice/Stakeholders-call-for-intensified-consultations-on-Nigerian-rice-sector-trade | title = Shareholders call for intensified consultation on Nigerian rice sector trade | archive-url = https://web.archive.org/web/20140224033246/http://agritrade.cta.int/Agriculture/Commodities/Rice/Stakeholders-call-for-intensified-consultations-on-Nigerian-rice-sector-trade | archive-date = February 24, 2014 }}</ref> Parboiled rice is particularly popular in Nigeria. Although China and India are the two largest producers of rice in the world, both countries consume the majority of the rice produced domestically, leaving little to be traded internationally.


Rice is a commonly-eaten food around the world. The [[List of rice varieties|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 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|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.<ref name="Rice Association">{{cite web |title=Types of rice |url=https://www.riceassociation.org.uk/types-of-rice |publisher=The Rice Association |access-date=March 24, 2024}}</ref>
=== Yield records ===
The average world yield for rice was {{convert|4.3|MT/ha|ST/acre|abbr=off}}, in 2010. Australian rice farms were the most productive in 2010, with a nationwide average of {{convert|10.8|MT/ha|ST/acre|abbr=off}}.<ref>{{cite web|title=FAOSTAT: Production-Crops, 2010 data |publisher= United Nations [[Food and Agriculture Organization]] (FAO) |year=2011 |url=http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567#ancor |url-status=dead |archive-url=https://web.archive.org/web/20150906230329/http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567 |archive-date=September 6, 2015}}</ref>


=== Nutrition ===
[[Yuan Longping]] of China National Hybrid Rice Research and Development Center set a world record for rice yield in 2010 at {{convert|19|MT/ha|ST/acre|abbr=off}} on a demonstration plot. In 2011, this record was reportedly surpassed by an Indian farmer, Sumant Kumar, with {{convert|22.4|MT/ha|ST/acre|abbr=off}} in [[Bihar]], although this claim has been disputed by both Yuan and India's [[Central Rice Research Institute]]. These efforts employed newly developed rice breeds and [[System of Rice Intensification]] (SRI), a recent innovation in rice farming.<ref>{{cite web|title=A Scientist's Perspective on Experience with SRI in CHINA for Raising the Yields of Super Hybrid Rice |year=2010 | vauthors = Yuan LP |url= http://ciifad.cornell.edu/sri/proc1/sri_06.pdf |url-status=dead |archive-url=https://web.archive.org/web/20111120010557/http://ciifad.cornell.edu/sri/proc1/sri_06.pdf |archive-date=November 20, 2011}}</ref><ref>{{cite news|title=Indian farmer sets new world record in rice yield|newspaper=The [[Philippine Star]] |date=December 18, 2011|url=http://www.philstar.com/arts-and-culture/759471/fccp-holds-talks-cultural-concerns|access-date=March 14, 2014|archive-url=https://web.archive.org/web/20140110210941/http://www.philstar.com/arts-and-culture/759471/fccp-holds-talks-cultural-concerns|archive-date=January 10, 2014|url-status=live}}</ref><ref>{{cite magazine|title=Grassroots heroes lead Bihar's rural revolution|magazine=India Today|date=January 10, 2012 |url=http://indiatoday.intoday.in/story/grassroots-heroes-lead-rural-revolution-of-bihar/1/168028.html|archive-url=https://web.archive.org/web/20130103002917/http://indiatoday.intoday.in/story/grassroots-heroes-lead-rural-revolution-of-bihar/1/168028.html|archive-date=January 3, 2013}}</ref><ref>{{cite news |title=Chinese whispers over rice record - Scientist questions nalanda farmer paddy yield |url=https://www.telegraphindia.com/bihar/chinese-whispers-over-rice-record-scientist-questions-nalanda-farmer-paddy-yield/cid/330999 |access-date=August 31, 2021 |publisher= [[The Telegraph (India)|The Telegraph]] |date=February 23, 2013}}</ref>


Cooked white rice is 69% water, 29% [[carbohydrate]]s, 2% [[protein (nutrient)|protein]], and contains negligible [[fat]] (table). In a reference serving of {{convert|100|g}}, cooked white rice provides 130 [[calorie]]s of [[food energy]], and contains moderate levels of [[Manganese in biology|manganese]] (18% DV), with no other [[micronutrient]]s in significant content (all less than 10% of the [[Daily Value]]).<ref name="USDA FoodData Central">{{cite web |title=FoodData Central: Rice, white, medium-grain, cooked, unenriched |url=https://fdc.nal.usda.gov/fdc-app.html#/food-details/168930/nutrients |publisher=[[US Department of Agriculture]] |access-date=December 5, 2023 |date=April 2018}}</ref>
=== Price ===
In 2018, the [[World Health Organization]] strongly recommended [[food fortification|fortifying]] rice with [[iron]], and conditionally recommended fortifying it with [[vitamin A]] and with [[folic acid]].<ref name="whoguide">{{cite book |last1=L. M. |first1=De-Regil |last2=J. P. |first2=Peña-Rosas |last3=A. |first3=Laillou |last4=R. |first4=Moench-Pfanner |last5=L. A. |first5=Mejia |last6=A. M. |first6=Bower |last7=S. |first7=de Pee |last8=L. M. |first8=De-Regil |last9=P. S. |first9=Suchdev |last10=G. E. |first10=Vist |last11=S. |first11=Walleser |last12=J. P. |first12=Peña-Rosas |last13=N. B. |first13=Piccoli |last14=N. |first14=Grede |last15=S. |first15=de Pee |last16=A. |first16=Singhkumarwong |last17=E. |first17=Roks |last18=R. |first18=Moench-Pfanner |last19=M. W. |first19=Bloem |display-authors=5 | title=Guideline: Fortification of Rice with Vitamins and Minerals as a Public Health Strategy |publisher=[[World Health Organization]] |date=2018 |pmid=30307723 |isbn=978-92-4-155029-1 |url=https://www.ncbi.nlm.nih.gov/books/NBK531762/ |access-date=December 5, 2023}}</ref>
{{update section|date=October 2021}}
In late 2007 to May 2008, the price of grains rose greatly due to droughts in major producing countries (particularly Australia), increased use of grains for animal feed and US subsidies for bio-fuel production. Although there was no shortage of rice on world markets this general upward trend in grain prices led to panic buying by consumers, government rice export bans (in particular, by Vietnam and India) and inflated import orders by the Philippines marketing board, the National Food Authority. This caused significant rises in rice prices. In late April 2008, prices hit 24 [[US cent]]s a [[pound (mass)|pound]], twice the price of seven months earlier.<ref name=cyclone>{{cite web | url = http://news.bbc.co.uk/2/hi/business/7387251.stm | title = Cyclone fuels rice price increase | archive-url = https://web.archive.org/web/20111025005847/http://news.bbc.co.uk/2/hi/business/7387251.stm | archive-date = October 25, 2011 | work = [[BBC News]] | date = May 7, 2008 }}</ref> Over the period of 2007 to 2013, the Chinese government has substantially increased the price it pays domestic farmers for their rice, rising to {{currency|500}} per metric ton by 2013.<ref name=cendrowski2013/> The 2013 price of rice originating from other southeast Asian countries was a comparably low {{currency|350}} per metric ton.<ref name=cendrowski2013/>


=== Golden rice ===
On April 30, 2008, Thailand announced plans for the creation of the [[Organisation of Rice Exporting Countries]] (OREC) with the intention that this should develop into a price-fixing [[cartel]] for rice.<ref>{{cite web | url = http://www.radioaustralia.net.au/international/2008-04-30/mekong-nations-to-form-rice-pricefixing-cartel/38466 | title = Mekong nations to form rice price-fixing cartel | archive-url = https://web.archive.org/web/20131023231349/http://www.radioaustralia.net.au/international/2008-04-30/mekong-nations-to-form-rice-pricefixing-cartel/38466 | archive-date = October 23, 2013 | work = [[Radio Australia]] | date = April 30, 2008 }}</ref><ref>{{cite web | url = https://groups.yahoo.com/neo/groups/archive-laonews/conversations/topics/14473 | title = PM floats idea of five-nation rice cartel | archive-url = https://web.archive.org/web/20140314041948/https://groups.yahoo.com/neo/groups/archive-laonews/conversations/topics/14473 | archive-date = March 14, 2014 | work = [[Bangkok Post]] | date = May 1, 2008 }}</ref> However, {{as of|2011|6|alt=as of mid-2011}} little progress had been made to achieve this.


{{main|Golden rice}}
=== Worldwide consumption ===
{{Update section|date=January 2023}}
{| class="wikitable" style="float:right; clear:left; width:21em; margin-left:1ex;"
! colspan=2|'''Food consumption of rice in 2013'''<br><small>(millions of metric tons of paddy equivalent)</small><ref name=con>{{cite web | url=http://faostat.fao.org/site/616/DesktopDefault.aspx?PageID=616#ancor | title=Food Balance Sheets > Commodity Balances > Crops Primary Equivalent | last=[[FAOSTAT]] | access-date=October 3, 2019 | archive-url=https://web.archive.org/web/20160402142135/http://faostat.fao.org/site/616/DesktopDefault.aspx?PageID=616#ancor | archive-date=April 2, 2016 | url-status=live}}</ref>
|-
| {{Flagu|China}} || style="text-align:center;"| 162.4
|-
| {{Flagu|India}} || style="text-align:center;"| 130.4
|-
| {{Flagu|Indonesia}} || style="text-align:center;"| 50.4
|-
| {{Flagu|Bangladesh}} || style="text-align:center;"| 40.3
|-
| {{Flagu|Vietnam}} || style="text-align:center;"| 19.9
|-
| {{Flagu|Philippines}} || style="text-align:center;"| 17.6
|-
| {{Flagu|Thailand}} || style="text-align:center;"| 11.5
|-
| {{Flagu|Japan}} || style="text-align:center;"| 11.4
|-
|}
{{As of|2013}}, world food consumption of rice was {{convert|565.6|e6MT|e6ST|abbr=off}} of paddy equivalent ({{convert|377,283|MT|ST|0}} of milled equivalent), while the largest consumers were China consuming {{convert|162.4|e6MT|e6ST|abbr=off}} of paddy equivalent (28.7% of world consumption) and India consuming {{convert|130.4|e6MT|e6ST|abbr=off}} of paddy equivalent (23.1% of world consumption).<ref name=con/>


Golden rice 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.<ref name="Golden Rice">{{cite web |title=Golden Rice Q&A |url=http://www.goldenrice.org/Content3-Why/why3_FAQ.php#Solution |publisher=Golden Rice Project |access-date=January 3, 2024}}</ref><ref name="Ye Al-Babili Klöti Zhang 2000 pp. 303–305">{{cite journal |last1=Ye |first1=Xudong |last2=Al-Babili |first2=Salim |last3=Klöti |first3=Andreas |last4=Zhang |first4=Jing |last5=Lucca |first5=Paola |last6=Beyer |first6=Peter |last7=Potrykus |first7=Ingo |author7-link=Ingo Potrykus |display-authors=5 |title=Engineering the Provitamin A (β-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm |journal=[[Science (journal)|Science]] |volume=287 |issue=5451 |date=January 14, 2000 |doi=10.1126/science.287.5451.303 |pages=303–305 |pmid=10634784 |bibcode=2000Sci...287..303Y |s2cid=40258379 }}</ref> Golden rice has been opposed by activists, such as in the [[Philippines]].<ref name="Lynas">{{cite web |last=Lynas |first=Mark |date=August 26, 2013 |title=Anti-GMO Activists Lie About Attack on Rice Crop (and About So Many Other Things) |url=https://slate.com/technology/2013/08/golden-rice-attack-in-philippines-anti-gmo-activists-lie-about-protest-and-safety.html |access-date=August 21, 2021 |website=[[Slate (magazine)|Slate Magazine]]}}</ref> In 2016 more than 100 [[Nobel laureate]]s encouraged the use of [[genetically modified organism]]s, such as golden rice, for the benefits these could bring.<ref name="Roberts 2018">{{cite journal |last=Roberts |first=Richard J. |title=The Nobel Laureates' Campaign Supporting GMOs |journal=Journal of Innovation & Knowledge |volume=3 |issue=2 |date=2018 |doi=10.1016/j.jik.2017.12.006 |pages=61–65|doi-access=free }}</ref>
Between 1961 and 2002, per capita consumption of rice increased by 40% worldwide.<ref>{{Cite book |last=Gnanamanickam |first=Samuel |title=Biological Control of Rice Diseases |publisher=Springer |year=2009 |isbn=978-9048124640 |pages=5 |language=en}}</ref> A paper from the Korean Society of Crop Science anticipated that consumption would increase to {{ Convert | 590 | e6t | abbr=off }} by 2040, and that consumption would decline in Asia and increase in other parts of the world.<ref>Bhandari, Humnath. [https://www.koreascience.or.kr/article/CFKO201932468198493.page "Global rice production, consumption and trade: trends and future directions."] ''[[Proceedings of the Korean Society of Crop Science Conference]]''. The [[Korean Society of Crop Science]], 2019.</ref>


== Rice and climate change ==
Rice is the most important crop in Asia. In Cambodia, for example, 90% of the total agricultural area is used for rice production.<ref>{{cite book |url=http://sidharta.com/books/index.jsp?uid=67 |title=The Burning of the Rice |vauthors=Puckridge D |date=2004 |publisher= [[Temple House Pty]] |isbn=978-1-877059-73-5 |archive-url=https://web.archive.org/web/20140331134952/http://sidharta.com/books/index.jsp?uid=67 |archive-date=March 31, 2014}}</ref> Per capita, [[Bangladesh]] ranks as the country with the highest rice consumption, followed by [[Laos]], [[Cambodia]], [[Vietnam]] and [[Indonesia]].<ref>{{Cite web|url=https://www.helgilibrary.com/indicators/rice-consumption-per-capita/|title = Rice Consumption per Capita}}</ref>


U.S. rice consumption has risen sharply over the past 25 years, fueled in part by commercial applications such as beer production.<ref>{{cite web|url=http://www.ers.usda.gov/Briefing/Rice/ |title=Briefing Rooms: Rice |last= United States Department of Agriculture (USDA) [[Economic Research Service]] |access-date=April 24, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080409111047/http://www.ers.usda.gov/Briefing/Rice/ |archive-date=April 9, 2008}}</ref> Almost one in five adult Americans now report eating at least half a serving of white or brown rice per day.<ref>{{cite report | url=http://publications.iowa.gov/2781/ | vauthors = Batres-Marquez SP, Jensen HH | title=Rice Consumption in the United States: New Evidence from Food Consumption Surveys | publisher = [[Iowa State University]] (ISU) | date=July 2005 | access-date=April 24, 2008 | archive-url=https://web.archive.org/web/20100528150926/http://publications.iowa.gov/2781/ | archive-date=May 28, 2010 | url-status=live}}</ref>


<!--- The first section is transcribed to [[greenhouse gas emissions from agriculture]], the second section is transcribed to [[effects of climate change on agriculture]]. -->
== Environmental impacts ==
[[File:NP Rice Emissions18 (5687953086).jpg|thumb|right|Work by the [[International Center for Tropical Agriculture]] to measure the greenhouse gas emissions of rice production.]]


=== Greenhouse gases from rice production ===
=== Climate change ===
<!--- The first para is transcribed to [[greenhouse gas emissions from agriculture]], the second para is transcribed to [[effects of climate change on agriculture]]. More content could still be added. -->
The worldwide production of rice accounts for more [[greenhouse gas emissions]] (GHG) in total than that of any other plant food.<ref name="The Guardian-2021">{{Cite web|date=September 13, 2021|title=Meat accounts for nearly 60% of all greenhouse gases from food production, study finds|url=https://www.theguardian.com/environment/2021/sep/13/meat-greenhouses-gases-food-production-study|access-date=October 14, 2021|website= [[The Guardian]] |language=en}}</ref> It was estimated in 2021 to be responsible for 30% of agricultural [[methane emissions]] and 11% of agricultural [[nitrous oxide]] emissions.<ref>{{cite journal | vauthors = Gupta K, Kumar R, Baruah KK, Hazarika S, Karmakar S, Bordoloi N | title = Greenhouse gas emission from rice fields: a review from Indian context | journal = [[Environmental Science and Pollution Research International]] | volume = 28 | issue = 24 | pages = 30551–30572 | date = June 2021 | pmid = 33905059 | doi = 10.1007/s11356-021-13935-1 | s2cid = 233403787 }}</ref> Methane release is caused by long-term flooding of rice fields, inhibiting the soil from absorbing atmospheric oxygen, a process causing [[anaerobic fermentation]] of organic matter in the soil.<ref name="heinz">{{cite journal | vauthors = Neue HU | year = 1993 | title = Methane emission from rice fields: Wetland rice fields may make a major contribution to global warming | url = http://www.ciesin.org/docs/004-032/004-032.html | journal = [[BioScience]] | volume = 43 | issue = 7 | pages = 466–73 | doi = 10.2307/1311906 | jstor = 1311906 | access-date = February 4, 2008 | archive-url = https://web.archive.org/web/20080115013146/http://www.ciesin.org/docs/004-032/004-032.html | archive-date = January 15, 2008 | url-status = dead}}</ref> A 2021 study estimated that rice contributed 2 billion tonnes of [[Greenhouse gas|anthropogenic greenhouse gases]] in 2010,<ref name="The Guardian-2021" /> of the 47 billion total.<ref>{{Cite web| vauthors = Charles K |title=Food production emissions make up more than a third of global total|url=https://www.newscientist.com/article/2290068-food-production-emissions-make-up-more-than-a-third-of-global-total/|access-date=October 14, 2021|website=New Scientist|language=en-US}}</ref> The study added up GHG emissions from the entire lifecycle, including production, transportation, and consumption, and compared the global totals of different foods.<ref>{{Cite journal| vauthors = Xu X, Sharma P, Shu S, Lin TS, Ciais P, Tubiello FN, Smith P, Campbell N, Jain AK |date=September 2021|title=Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods= |journal= [[Nature Food]] |language=en|volume=2|issue=9|pages=724–732|doi=10.1038/s43016-021-00358-x|pmid=37117472 |hdl=2164/18207|s2cid=240562878|issn=2662-1355|hdl-access=free}}</ref> The total for rice was half the total for beef.<ref name="The Guardian-2021" />


[[File:NP Rice Emissions18 (5687953086).jpg|thumb|Scientists measuring the greenhouse gas emissions of rice]]
A 2010 study found that, as a result of rising temperatures and decreasing solar radiation during the later years of the 20th century, the rice yield growth rate has decreased in many parts of Asia, compared to what would have been observed had the temperature and solar radiation trends not occurred.<ref>{{cite journal | vauthors = Welch JR, Vincent JR, Auffhammer M, Moya PF, Dobermann A, Dawe D | title = Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 107 | issue = 33 | pages = 14562–14567 | date = August 2010 | pmid = 20696908 | pmc = 2930450 | doi = 10.1073/pnas.1001222107 | doi-access = free | bibcode = 2010PNAS..10714562W }}</ref><ref>{{cite web | vauthors = Black R | date = August 9, 2010 | url = https://www.bbc.co.uk/news/science-environment-10918591 | title = Rice yields falling under global warming | archive-url = https://web.archive.org/web/20180405034821/http://www.bbc.co.uk/news/science-environment-10918591 | archive-date = April 5, 2018 | work = [[BBC News Science & Environment]] | access-date = August 9, 2010 }}</ref> The yield growth rate had fallen 10–20% at some locations. The study was based on records from 227 farms in Thailand, Vietnam, Nepal, India, China, Bangladesh, and Pakistan. The mechanism of this falling yield was not clear, but might involve increased respiration during warm nights, which expends energy without being able to photosynthesize. More detailed analysis of rice yields by the [[International Rice Research Institute]] forecast 20% reduction in yields in Asia per degree Celsius of temperature rise. Rice becomes sterile if exposed to temperatures above {{Convert|35|C}} for more than one hour during flowering and consequently produces no grain.<ref>{{Cite journal | vauthors = Singh SK |date=2016 |title=Climate Change: Impact on Indian Agriculture & its Mitigation |journal=Journal of Basic and Applied Engineering Research |volume=3 |issue=10 |pages=857–859}}</ref><ref>{{Cite book | vauthors = Rao P, Patil Y |url=https://books.google.com/books?id=st52DQAAQBAJ&pg=PA330 |title=Reconsidering the Impact of Climate Change on Global Water Supply, Use, and Management |publisher= [[IGI Global]] |year=2017 |isbn=978-1-5225-1047-5 |page=330 |language=en |name-list-style=vanc}}</ref>


In 2022, [[greenhouse gas emissions]] from rice cultivation were estimated at 5.7 billion tonnes CO2eq, representing 1.2% of total emissions.<ref>{{Cite web |title=Sectors: Rice cultivation |url=https://climatetrace.org/sectors |access-date=December 7, 2023 |website=climatetrace.org}}</ref> Within the agriculture sector, rice produces almost half the greenhouse gas emissions from [[croplands]],<ref>{{Cite journal |last1=Qian |first1=Haoyu |last2=Zhu |first2=Xiangchen |last3=Huang |first3=Shan |last4=Linquist |first4=Bruce |last5=Kuzyakov |first5=Yakov |last6=Wassmann |first6=Reiner |last7=Minamikawa |first7=Kazunori |last8=Martinez-Eixarch |first8=Maite |last9=Yan |first9=Xiaoyuan |last10=Zhou |first10=Feng |last11=Sander |first11=Bjoern Ole |last12=Zhang |first12=Weijian |last13=Shang |first13=Ziyin |last14=Zou |first14=Jianwen |last15=Zheng |first15=Xunhua |display-authors=5 |date=October 2023 |title=Greenhouse gas emissions and mitigation in rice agriculture |journal=Nature Reviews Earth & Environment |volume=4 |issue=10 |pages=716–732 |doi=10.1038/s43017-023-00482-1 |bibcode=2023NRvEE...4..716Q |s2cid=263197017 |quote=Rice paddies …. account for ~48% of greenhouse gas (GHG) emissions from croplands.|hdl=20.500.12327/2431 |hdl-access=free }}</ref> some 30% of agricultural [[methane emissions]], and 11% of agricultural [[nitrous oxide]] emissions.<ref>{{cite journal |last1=Gupta |first1=Khushboo |last2=Kumar |first2=Raushan |last3=Baruah |first3=Kushal Kumar |last4=Hazarika |first4=Samarendra |last5=Karmakar |first5=Susmita |last6=Bordoloi |first6=Nirmali |title=Greenhouse gas emission from rice fields: a review from Indian context |journal=Environmental Science and Pollution Research International |volume=28 |issue=24 |pages=30551–30572 |date=June 2021 |pmid=33905059 |doi=10.1007/s11356-021-13935-1 |bibcode=2021ESPR...2830551G |s2cid=233403787 }}</ref> [[Methane]] is released from rice fields subject to long-term flooding, as this inhibits the soil from absorbing atmospheric oxygen, resulting in [[anaerobic fermentation]] of organic matter in the soil.<ref name="heinz">{{cite journal |last1=Neue |first1=Heinz-Ulrich |title=Methane Emission from Rice Fields |journal=BioScience |date=1993 |volume=43 |issue=7 |pages=466–474 |doi=10.2307/1311906 |jstor=1311906 }}</ref> Emissions can be limited by planting new varieties, not flooding continuously, and removing straw.<ref name="Qian Zhu Huang 2023">{{Cite journal |last1=Qian |first1=Haoyu |last2=Zhu |first2=Xiangchen |last3=Huang |first3=Shan |last4=Linquist |first4=Bruce |last5=Kuzyakov |first5=Yakov |last6=Wassmann |first6=Reiner |last7=Minamikawa |first7=Kazunori |last8=Martinez-Eixarch |first8=Maite |last9=Yan |first9=Xiaoyuan |last10=Zhou |first10=Feng |last11=Sander |first11=Bjoern Ole |last12=Zhang |first12=Weijian |last13=Shang |first13=Ziyin |last14=Zou |first14=Jianwen |last15=Zheng |first15=Xunhua |display-authors=5 |date=October 2023 |title=Greenhouse gas emissions and mitigation in rice agriculture |journal=Nature Reviews Earth & Environment |volume=4 |issue=10 |pages=716–732 |doi=10.1038/s43017-023-00482-1 |bibcode=2023NRvEE...4..716Q |s2cid=263197017 |hdl=20.500.12327/2431 |hdl-access=free }}</ref>
=== Water usage ===
Rice requires slightly more water to produce than other grains.<ref>{{cite web | url = http://www.waterfootprint.org/Reports/Report12.pdf | title = Virtual Water Trade – Proceedings of the International Expert Meeting on Virtual Water Trade | archive-url = https://web.archive.org/web/20141003175454/http://www.waterfootprint.org/Reports/Report12.pdf| archive-date = October 3, 2014 | page = 108 }}</ref> Rice production uses almost a third of Earth's fresh water.<ref>{{cite news|title=How better rice could save lives: A second green revolution|newspaper= [[The Economist]] |url=https://www.economist.com/news/leaders/21601850-technological-breakthroughs-rice-will-boost-harvests-and-cut-poverty-they-deserve-support|url-status=live|access-date=October 6, 2014|archive-url=https://web.archive.org/web/20141010044252/http://www.economist.com/news/leaders/21601850-technological-breakthroughs-rice-will-boost-harvests-and-cut-poverty-they-deserve-support|archive-date=October 10, 2014}}</ref> Water outflows from rice fields through [[transpiration]], [[evaporation]], seepage, and [[percolation]].<ref name="ResearchGate">{{Cite web|title=How much water does rice use?|url=https://www.researchgate.net/publication/281474989|access-date=September 12, 2021|website=ResearchGate|language=en}}</ref> It is estimated that it takes about {{convert|2,500|L|USgal}} of water need to be supplied to account for all of these outflows and produce {{convert|1|kg|lboz}} of rice.<ref name="ResearchGate" />


It is possible to cut methane emissions in rice cultivation by improved water management, combining dry seeding and one drawdown, or executing [[alternate wetting and drying|a sequence of wetting and drying]]. This results in emission reductions of up to 90% compared to full flooding and even increased yields.<ref>{{cite web |last1=Searchinger |first1=Tim |last2=Adhya |first2=Tapan K. |year=2014 |title=Wetting and Drying: Reducing Greenhouse Gas Emissions and Saving Water from Rice Production |url=https://www.wri.org/research/wetting-and-drying-reducing-greenhouse-gas-emissions-and-saving-water-rice-production |publisher=[[World Resources Institute]]}}</ref>
{{ Anchor | Pests | Diseases }}
== Pests and diseases ==
Rice pests are any [[organism]]s or [[microbe]]s with the potential to reduce the yield or value of the rice crop (or of rice seeds).<ref>{{cite book|title=Ecologically Based Integrated Pest Management|year=2007|publisher=CABI ([[Centre for Agriculture and Bioscience International]])|isbn=978-1-84593-064-6| vauthors = Jahn GC, Litsinger JA, Chen Y, Barrion AT |chapter=Integrated Pest Management of Rice: Ecological Concepts | veditors = Koul O, Cuperus GW |pages=315–66}}</ref> Rice pests include weeds, [[pathogen]]s, insects, nematode, rodents, and birds. A variety of factors can contribute to pest outbreaks, including climatic factors, improper irrigation, the overuse of [[insecticides]] and high rates of [[nitrogen fertilizer]] application.<ref>{{cite journal|doi=10.1603/0046-225X-34.4.938|title=Effect of Nitrogen Fertilizer on the Intrinsic Rate of Increase of ''Hysteroneura setariae'' (Thomas) (Homoptera: Aphididae) on Rice (''Oryza sativa'' L.)|year=2005| vauthors = Jahn GC, Almazan LP, Pacia JB |s2cid=1941852|journal= [[Environmental Entomology]] |volume=34|issue=4|page=938|doi-access=free}}</ref> Weather conditions also contribute to pest outbreaks. For example, rice [[gall midge]] and [[Spodoptera mauritia|army worm]] outbreaks tend to follow periods of high rainfall early in the wet season, while [[thrips]] outbreaks are associated with drought.<ref>{{cite book | vauthors = Douangboupha B, Khamphoukeo K, Inthavong S, Schiller J, Jahn GC | date = 2006 | chapter-url = http://aciar.gov.au/files/node/756/Rice%20In%20Laos%20chapter%2016-25.pdf | chapter = Chapter 17: Pests and diseases of the rice production systems of Laos | archive-url = https://web.archive.org/web/20120403052249/http://aciar.gov.au/files/node/756/Rice%20In%20Laos%20chapter%2016-25.pdf | archive-date=April 3, 2012 | pages = 265–281 | veditors = Schiller JM, Chanphengxay MB, Linquist B, Rao SA | title = Rice in Laos | publisher = IRRI (the [[International Rice Research Institute]]) | location = [[Los Baños, Philippines]] | isbn = 978-971-22-0211-7 }}</ref>


=== Effects of climate change on rice production ===
===Animal pests===
==== Insects ====
[[File:Chinese rice grasshopper (Oxya chinensis).jpg|thumb|Chinese rice grasshopper<br>(''Oxya chinensis'')<br>[[Borneo]], [[Malaysia]]]]
Major rice insect pests include: the [[brown planthopper]] (BPH),<ref>{{cite journal|url=http://www.cardi.org.kh/images/stories/CJA/Vol07-N01-Jan-Jun-2006.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.cardi.org.kh/images/stories/CJA/Vol07-N01-Jan-Jun-2006.pdf |archive-date=October 9, 2022 |url-status=live | vauthors = Preap V, Zalucki MP, Jahn GC |year=2006 |title=Brown planthopper outbreaks and management |journal=Cambodian Journal of Agriculture |volume=7 |issue=1 |pages=17–25}}{{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}</ref> several species of [[stemborer]]s—including those in the genera ''[[Scirpophaga]]'' and ''[[Chilo suppressalis|Chilo]]'',<ref name="RKB">{{cite web|title=IRRI Rice insect pest factsheet: Stem borer |publisher=Rice Knowledge Bank|url=http://www.knowledgebank.irri.org/training/fact-sheets/pest-management/insects/item/stem-borer |archive-url=https://web.archive.org/web/20141122174830/http://www.knowledgebank.irri.org/training/fact-sheets/pest-management/insects/item/stem-borer |archive-date=November 22, 2014|url-status=live}}</ref> the rice [[gall midge]],<ref>Benett J, Bentur JC, Pasula IC and Krishnaiah K (eds) (2004). [https://web.archive.org/web/20130507075104/http://dspace.irri.org:8080/dspace/bitstream/123456789/326/2/9712201988_content.pdf ''New approaches to gall midge resistance in rice'']. International Rice Research Institute and Indian Council of Agricultural Research, {{ISBN|971-22-0198-8}}.</ref> several species of [[Rice bug (disambiguation)|rice bug]]s<!--intentional link to DAB page-->,<ref name=j1/> notably in the genus ''[[Leptocorisa]]'',<ref>{{cite journal | vauthors = Jahn GC, Domingo I, Almazan ML, Pacia J | title = Effect of rice bug ''Leptocorisa oratorius'' (Hemiptera: Alydidae) on rice yield, grain quality, and seed viability | journal = [[Journal of Economic Entomology]] | volume = 97 | issue = 6 | pages = 1923–1927 | date = December 2004 | pmid = 15666746 | doi = 10.1603/0022-0493-97.6.1923 | s2cid = 23278521 }}</ref> defoliators such as the rice: [[Cnaphalocrocis medinalis|leafroller]], [[Dicladispa armigera|hispa]] and [[Oxya|grasshoppers]].<ref>{{Cite web |url=http://www.plantwise.org/KnowledgeBank/Datasheet.aspx?dsid=38206%7CPlantwise |title=Knowledge Bank |access-date=November 13, 2019 |archive-url=https://web.archive.org/web/20160704062639/http://www.plantwise.org/KnowledgeBank/Datasheet.aspx?dsid=38206%7CPlantwise |archive-date=July 4, 2016 |url-status=live}}</ref> The [[Fall armyworm|fall army worm]], a species of Lepidoptera, also targets and causes damage to rice crops.<ref>{{Cite web|url=http://entnemdept.ufl.edu/creatures/field/fall_armyworm.htm|title=fall armyworm, ''Spodoptera frugiperda'' (J.E. Smith)|website=[[University of Florida]] entnemdept.ufl.edu|access-date=November 15, 2017|archive-url=https://web.archive.org/web/20171002022148/http://entnemdept.ufl.edu/creatures/field/fall_armyworm.htm|archive-date=October 2, 2017|url-status=live}}</ref> [[Rice weevil]]s attack stored produce.


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<ref>{{Cite journal |last1=Zhao |first1=Chuang |last2=Liu |first2=Bing |last3=Piao |first3=Shilong |last4=Wang |first4=Xuhui |last5=Lobell |first5=David B. |last6=Huang |first6=Yao |last7=Huang |first7=Mengtian |last8=Yao |first8=Yitong |last9=Bassu |first9=Simona |last10=Ciais |first10=Philippe |last11=Durand |first11=Jean-Louis |last12=Elliott |first12=Joshua |last13=Ewert |first13=Frank |last14=Janssens |first14=Ivan A. |last15=Li |first15=Tao |display-authors=5 |date=2017-08-29 |title=Temperature increase reduces global yields of major crops in four independent estimates |journal=[[Proceedings of the National Academy of Sciences of the United States of America|Proceedings of the National Academy of Sciences]] |volume=114 |issue=35 |pages=9326–9331 |doi=10.1073/pnas.1701762114 |doi-access=free |pmc=5584412 |pmid=28811375 |bibcode=2017PNAS..114.9326Z }}</ref> while another study predicts global rice cultivation will increase initially, plateauing at about 3°C warming (2091–2100 relative to 1850–1900).<ref>{{Cite journal |last1=Iizumi |first1=Toshichika |last2=Furuya |first2=Jun |last3=Shen |first3=Zhihong |last4=Kim |first4=Wonsik |last5=Okada |first5=Masashi |last6=Fujimori |first6=Shinichiro |last7=Hasegawa |first7=Tomoko |last8=Nishimori |first8=Motoki |display-authors=5 |date=2017-08-10 |title=Responses of crop yield growth to global temperature and socioeconomic changes |journal=Scientific Reports |volume=7 |issue=1 |pages=7800 |doi=10.1038/s41598-017-08214-4 |pmid=28798370 |pmc=5552729 |bibcode=2017NatSR...7.7800I}}</ref><!--<ref>{{cite book |doi=10.1017/9781009157988.007 |chapter=Food security |title=Climate Change and Land |date=2022 |pages=437–550 |isbn=978-1-009-15798-8 |author=Intergovernmental Panel on Climate Change }}</ref>-->
==== Nematodes ====
{{ Uncited section |date=January 2023}}
Several [[nematode]] species infect rice crops, causing diseases such as Ufra (''[[Ditylenchus dipsaci]]''), White tip disease (''[[Aphelenchoide bessei]]''), and root knot disease (''[[Meloidogyne graminicola]]''). Some nematode species such as ''[[Pratylenchus]]'' spp. are most dangerous in upland rice of all parts of the world. Rice root nematode (''[[Hirschmanniella oryzae]]'') is a migratory endoparasite which on higher inoculum levels will lead to complete destruction of a rice crop. Beyond being obligate parasites, they also decrease the vigor of plants and increase the plants' susceptibility to other pests and diseases.


The impacts of climate change on rice cultivation vary across geographic location and socioeconomic context. For example, rising temperatures and decreasing solar radiation during 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.<ref name="Welch Vincent Auffhammer Moya 2010">{{cite journal |last1=Welch |first1=Jarrod R. |last2=Vincent |first2=Jeffrey R. |last3=Auffhammer |first3=Maximilian |last4=Moya |first4=Piedad F. |last5=Dobermann |first5=Achim |last6=Dawe |first6=David |title=Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures |journal=Proceedings of the National Academy of Sciences |volume=107 |issue=33 |date=August 9, 2010 |doi=10.1073/pnas.1001222107 |pages=14562–14567 |pmid=20696908 |pmc=2930450 |doi-access=free }}</ref><ref name="Black 2010">{{cite web |last=Black |first=R. |date=August 9, 2010 |url=https://www.bbc.co.uk/news/science-environment-10918591 |title=Rice yields falling under global warming |archive-url=https://web.archive.org/web/20180405034821/http://www.bbc.co.uk/news/science-environment-10918591 |archive-date=April 5, 2018 |work=[[BBC News]]: Science & Environment |access-date=August 9, 2010 }}</ref> 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 the crop would be lost under these conditions.<ref name="Singh 2016">{{cite journal |last=Singh |first=S.K. |date=2016 |title=Climate Change: Impact on Indian Agriculture & its Mitigation |journal=Journal of Basic and Applied Engineering Research |volume=3 |issue=10 |pages=857–859}}</ref><ref name="Rao Patil 2017">{{cite book |last1=Rao |first1=Prakash |last2=Patil |first2=Y. |url=https://books.google.com/books?id=st52DQAAQBAJ&pg=PA330 |title=Reconsidering the Impact of Climate Change on Global Water Supply, Use, and Management |publisher=IGI Global |year=2017 |isbn=978-1-5225-1047-5 |page=330}}</ref>
==== Other pests ====
These include the apple snail (''[[Pomacea canaliculata]]''), [[panicle rice mite]], [[rat]]s,<ref>Singleton G, Hinds L, Leirs H and Zhang Zh (Eds.) (1999) "Ecologically-based rodent management" ACIAR, [[Canberra]]. Ch. 17, pp. 358–71 {{ISBN|1-86320-262-5}}.</ref> and the weed [[Echinochloa crus-galli]].<ref>{{cite journal|vauthors=Pheng S, B Khiev B, Pol C, Jahn GC|year=2001|title=Response of two rice cultivars to the competition of Echinochloa crus-gali (L.) P. Beauv|journal=International Rice Research Institute Notes (IRRN)|volume=26|issue=2|pages=36–37|url=http://ejournals.ph/index.php?journal=IRRN&page=article&op=view&path&#91;&#93;=4318|access-date=November 13, 2019|archive-url=https://web.archive.org/web/20181118230344/https://ejournals.ph/index.php?journal=IRRN&page=article&op=view&path%255B%255D=4318|archive-date=November 18, 2018|url-status=live}}</ref>


In the [[Po Valley]] in Italy, the [[Arborio rice|arborio]] and [[carnaroli]] risotto rice varieties have suffered poor harvests through drought in the 21st century. The {{ill|Ente Nazionale Risi|it}} <!--(Italian rice research institute)--> is developing drought-resistant varieties; its ''nuovo prometeo'' variety has deep roots that enable it to tolerate drought, but is not suitable for risotto.<ref name="Spaggiari 2024">{{cite news |last=Spaggiari |first=Ottavia |title=Risotto crisis: the fight to save Italy's beloved dish from extinction |url=https://www.theguardian.com/environment/2024/feb/29/risotto-crisis-the-fight-to-save-italys-beloved-dish-from-extinction-aoe |work=[[The Guardian]] |date=February 29, 2024}}</ref>
=== Diseases ===
{{ Main | List of rice diseases }}
[[Rice blast]], caused by the fungus ''[[Magnaporthe grisea]]'' ([[taxonomic synonym|syn.]] ''M. oryzae'', ''Pyricularia oryzae''),<ref>{{cite journal | vauthors = Dean RA, Talbot NJ, Ebbole DJ, Farman ML, Mitchell TK, Orbach MJ, Thon M, Kulkarni R, Xu JR, Pan H, Read ND, Lee YH, Carbone I, Brown D, Oh YY, Donofrio N, Jeong JS, Soanes DM, Djonovic S, Kolomiets E, Rehmeyer C, Li W, Harding M, Kim S, Lebrun MH, Bohnert H, Coughlan S, Butler J, Calvo S, Ma LJ, Nicol R, Purcell S, Nusbaum C, Galagan JE, Birren BW | display-authors = 6 | title = The genome sequence of the rice blast fungus Magnaporthe grisea | journal = Nature | volume = 434 | issue = 7036 | pages = 980–986 | date = April 2005 | pmid = 15846337 | doi = 10.1038/nature03449 | author-link2 = Nick Talbot | doi-access = free | bibcode = 2005Natur.434..980D }}</ref> is the most significant disease affecting rice cultivation. It and [[bacterial leaf streak]] (caused by [[Xanthomonas oryzae pv. oryzae|''Xanthomonas oryzae'' pv. ''oryzae'']]) are perennially the two worst rice diseases worldwide, and such is their importance {{endash}} and the importance of rice {{endash}} that they are both among the worst 10 diseases of all plants.<ref group="Liu" name="Mg-Xoo-worst">p.{{nbs}}214, "Rice blast (caused by the fungal pathogen ''Magnaporthe oryzae'') and bacterial blight (caused by the bacterial pathogen ''Xanthomonas oryzae'' pv. ''oryzae'') are the most devastating rice diseases (119) and are among the 10 most important fungal and bacterial diseases in plants (32, 95). Owing to their scientific and economic importance, both pathosystems have been the focus of concentrated study over the past two decades, and they are now advanced molecular models for plant fungal and bacterial diseases."</ref> Fukuoka ''et al.'', 2009 [[gene cloning|clones]] one of the few [[quantitative disease loci]] for [[quantitative disease resistance]] ever cloned in plants, one for [[rice blast resistance|blast resistance in this crop]].<ref name = "QDR-QRL-breed" >
{{ Cite journal
| year = 2010
| publisher = [[Annual Reviews (publisher)|Annual Reviews]]
| volume = 48
| pages = 247–68
| title = Quantitative Disease Resistance and Quantitative Resistance Loci in Breeding
| last = St.Clair
| first = Dina
| journal = [[Annual Review of Phytopathology]]
| doi = 10.1146/annurev-phyto-080508-081904
| pmid = 19400646
| issn = 0066-4286
}}
</ref> The plant responds to the blast pathogen by releasing [[jasmonic acid]], which then cascades into the activation of further downstream [[metabolic pathway]]s which produce the defense response.<ref name = "Secondary-Metabolites" /> This accumulates as [[methyl-jasmonic acid]].<ref name = "Secondary-Metabolites" /> The pathogen responds by [[biosynthesis|synthesizing]] an [[oxidase|oxidizing enzyme]] which prevents this accumlation and its resulting alarm signal.<ref name = "Secondary-Metabolites" >
{{ Cite journal |
language=en|
year=2021|
issue=9–10|
volume=48|
publisher=[[Oxford University Press]] (OUP)|
journal=[[Journal of Industrial Microbiology and Biotechnology]]|
issn=1367-5435|
first3=Hiroyuki|
first2=Choong-Soo|
first1=Takayuki|
last3=Osada|
last2=Yun|
last1=Motoyama|
department=Natural Products – Review|
title=Biosynthesis and biological function of secondary metabolites of the rice blast fungus ''Pyricularia oryzae''|
doi=10.1093/jimb/kuab058|
pmid=34379774|
pmc=8788799|
id=[[Society of Industrial Microbiology and Biotechnology]]. TM {{ORCID|0000-0001-7602-2394}}. CSY {{ORCID|0000-0001-7128-2584}}. HO {{ORCID|0000-0002-3606-4925}}}}
</ref> {{ Visible anchor |OsPii-2|Pii-2|text=''Os''Pii-2}} was discovered by Fujisaki ''et al.'', 2017.<ref name="Show-Me-Your-ID" /> It is a [[nucleotide-binding leucine-rich repeat receptor]] (NB-LRR, NLR), an [[immunoreceptor]].<ref name="Show-Me-Your-ID" /> It includes an [[NOI domain]] (NO{{ Sub |3}}-Induced) which binds rice's own {{ Visible anchor |Exo70-F3}} [[protein]].<ref name="Show-Me-Your-ID" /> This protein is a target of the ''M. oryzae'' [[effector (biology)|effector]] {{ Visible anchor |AVR-Pii}} and so this allows the NLR to monitor for ''Mo''{{'}}s attack against that target.<ref name="Show-Me-Your-ID">
{{ Cite journal |
year=2022|
publisher=[[Portland Press Ltd.]]|
pages=527–539|
first5=Panagiotis|
first4=Volkan|
first3=Zhou|
first2=Vassiliki|
journal=[[Essays in Biochemistry]]|
issn=0071-1365|
first1=Clemence|
last5=Sarris|
last4=Cevik|
last3=Zou|
last2=Michalopoulou|
last1=Marchal|
doi=10.1042/ebc20210084|
title=Show me your ID: NLR immune receptors with integrated domains in plants|
volume=66|
issue=5|
pmid=35635051|
pmc=9528084}}</ref>


{{Anchor|Pests}}
Other major fungal and bacterial rice diseases include [[sheath blight]] (caused by ''[[Rhizoctonia solani]]''), false smut (''[[Ustilaginoidea virens]]''), bacterial panicle blight (''[[Burkholderia glumae]]''),<ref group="Liu" name="other-major-dis">p.{{nbs}}214, "...other diseases, including rice sheath blight (caused by the fungal pathogen ''Rhizoctonia solani''), false smut (caused by the fungal pathogen ''Ustilaginoidea virens''), bacterial leaf streak (caused by ''X. oryzae'' pv. ''oryzicola''), bacterial panicle blight (''Burkholderia glumae''), are emerging globally as important rice diseases (53, 72, 180) (Figure 1)."</ref> sheath rot (''[[Sarocladium oryzae]]''), and ''[[bakanae]]'' (''[[Fusarium fujikuroi]]'').<ref group="Liu" name="Table-1">p.{{nbs}}214, Table 1: Important fungal and bacterial diseases in rice.</ref> Viral diseases exist, such as [[Rice ragged stunt virus|rice ragged stunt]] ([[Vector (epidemiology)|vector]]: BPH), and [[Tungrovirus|tungro]] (vector: ''[[Nephotettix]]'' spp).<ref>{{cite web | url = http://www.knowledgebank.irri.org/ipm/index.php/diseases-crop-health-2733 | title = IRRI Rice Diseases factsheets | archive-url = https://web.archive.org/web/20131014011821/https://www.knowledgebank.irri.org/ipm/index.php/diseases-crop-health-2733 | archive-date = October 14, 2013 | work = Knowledgebank.irri.org | access-date = May 13, 2012 }}</ref> Many viral diseases, especially those [[vector (epidemiology)|vector]]ed by [[planthopper]]s and [[leafhopper]]s, are major causes of losses across the world.<ref name="Hibino-1996">{{cite journal | vauthors = Hibino H | title = Biology and epidemiology of rice viruses | journal = Annual Review of Phytopathology | volume = 34 | issue = 1 | pages = 249–274 | year = 1996 | pmid = 15012543 | doi = 10.1146/annurev.phyto.34.1.249 | publisher = [[Annual Reviews (publisher)|Annual Reviews]] }}</ref> There is also an [[ascomycete]] fungus, ''[[Cochliobolus miyabeanus]]'', that causes brown spot disease in rice.<ref>{{cite web | url = http://www.cbwinfo.com/Biological/PlantPath/CM.html | title = Rice Brown Spot: essential data | archive-url = https://web.archive.org/web/20130213012344/https://www.cbwinfo.com/Biological/PlantPath/CM.html | archive-date = February 13, 2013 | work = CBWinfo.com | access-date = May 13, 2012 }}</ref><ref>{{cite web | url = http://www.invasive.org/browse/tax.cfm?fam=683&genus=Cochliobolus | title = Cochliobolus | archive-url = https://web.archive.org/web/20110614205422/http://www.invasive.org/browse/tax.cfm?fam=683&genus=Cochliobolus | archive-date = June 14, 2011 | work = Invasive.org | date = May 4, 2010 | access-date = May 13, 2012 }}</ref><ref group="Liu" name="Table-1" />


== Pests, weeds, and diseases ==
[[File:Indian White Rice.jpg|thumb|White Rice]]


=== Integrated pest management ===
=== Pests and weeds ===
{{ Main | Integrated pest management }}
[[Crop protection]] scientists are trying to develop rice pest management techniques which are [[Sustainable agriculture|sustainable]]. In other words, to manage crop pests in such a manner that future crop production is not threatened.<ref>{{cite book | vauthors = Jahn GC, Khiev B, Pol C, Chhorn N, Pheng S, Preap V | date = 2001 | chapter = Developing sustainable pest management for rice in Cambodia.| pages = 243–258 | veditors = Suthipradit S, Kuntha C, Lorlowhakarn S, Rakngan J | title = Sustainable Agriculture: Possibility and Direction | location = Bangkok (Thailand) | publisher = National Science and Technology Development Agency }}</ref> Sustainable pest management is based on four principles: biodiversity, host plant resistance (HPR),<ref name="LSU-AgCenter-varieties-2021" /> landscape ecology, and hierarchies in a landscape—from biological to social.<ref>{{cite journal|doi=10.1016/j.cropro.2011.10.012|title=A review of principles for sustainable pest management in rice|year=2012| vauthors = Savary S, Horgan F, Willocquet L, Heong KL |journal=Crop Protection|volume=32|page=54}}</ref> At present, rice pest management includes cultural techniques, pest-resistant rice varieties,<ref name="LSU-AgCenter-varieties-2021" /> and [[pesticides]] (which include [[insecticide]]). Increasingly, there is evidence that farmers' pesticide applications are often unnecessary, and even facilitate pest outbreaks.<ref>{{cite report | vauthors = Jahn GC, Pheng S, Khiev B, Pol C | date = 1996 | title = Farmers' pest management and rice production practices in Cambodian lowland rice. | work = Cambodia-IRRI-Australia Project (CIAP), Baseline Survey Report No. 6. CIAP | location = Phnom Penh, Cambodia }}</ref><ref>{{cite web | url = http://www.scidev.net/Features/index.cfm?fuseaction=readfeatures&itemid=306&language=1 | title = Bangladeshi farmers banish insecticides | work = SCIDEV.net | date = July 30, 2004 | access-date = May 13, 2012 | archive-url = https://web.archive.org/web/20080126115934/http://www.scidev.net/Features/index.cfm?fuseaction=readfeatures&itemid=306&language=1 | archive-date = January 26, 2008 }}</ref><ref>{{YouTube|VKB-pg8EGMQ|IRRI.org}} (November 20, 2006). Retrieved on May 13, 2012.</ref><ref>{{cite journal|doi=10.1016/j.cropro.2010.07.009|title=Insecticide-induced increase in the protein content of male accessory glands and its effect on the fecundity of females in the brown planthopper Nilaparvata lugens Stål (Hemiptera: Delphacidae)|year=2010| vauthors = Wang LP, Shen J, Ge LQ, Wu JC, Yang GQ, Jahn GC |journal=Crop Protection|volume=29|issue=11|page=1280}}</ref> By reducing the populations of natural enemies of rice pests,<ref>{{cite journal | vauthors = Jahn GC |title=Rice pest control and effects on predators in Thailand |journal=Insecticide & Acaricide Tests |volume=17 |pages=252–53 |year=1992|doi=10.1093/iat/17.1.252 |doi-access=free }}</ref> misuse of insecticides can actually lead to pest outbreaks.<ref>{{cite journal|url=https://www.mendeley.com/catalogue/food-web-approach-evaluating-effect-insecticide-spraying-insect-pest-population-dynamics-philippine/| vauthors = Cohen JE, Schoenly K, Heong KL, Justo H, Arida G, Barrion AT, Litsinger JA |year=1994 |title=A Food-Web Approach to Evaluating the Effect of Insecticide Spraying on Insect Pest Population-Dynamics in a Philippine Irrigated Rice Ecosystem |journal=Journal of Applied Ecology |volume=31- |pages=747–63 |doi=10.2307/2404165 |issue=4 |jstor=2404165 }}</ref> 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.<ref>{{cite web |url=http://irri.org/knowledge/publications/rice-today/special-reports/science-shorts/the-pesticide-paradox |archive-url=https://web.archive.org/web/20120119053923/http://irri.org/knowledge/publications/rice-today/special-reports/science-shorts/the-pesticide-paradox |title=The pesticide paradox | vauthors = Hamilton HS |date=January 18, 2008 |archive-date=January 19, 2012}}</ref> IRRI also conducted two campaigns in 1994 and 2003, respectively, which discouraged insecticide misuse and smarter pest management in Vietnam.<ref>{{cite web | url = http://ricehoppers.net/2010/10/three-reduction-three-gains-a-factor-in-vietnam%E2%80%99s-continuing-success-says-thai-report/ | title = Three Gains, Three Reductions | archive-url = https://web.archive.org/web/20110820064642/https://ricehoppers.net/2010/10/three-reduction-three-gains-a-factor-in-vietnam%E2%80%99s-continuing-success-says-thai-report/ | archive-date = August 20, 2011 | work = Ricehoppers.net | date = October 12, 2010 | access-date = May 13, 2012 }}</ref><ref>{{cite web | url = http://ricehoppers.net/wp-content/uploads/2010/04/Escalada-et-al-2009.pdf | title = No Early Spray | archive-url = https://web.archive.org/web/20110623111926/https://ricehoppers.net/wp-content/uploads/2010/04/Escalada-et-al-2009.pdf | archive-date = June 23, 2011 | work = ricehoppers.net | date = April 2010 | access-date = May 13, 2012 }}</ref>


[[File:Chinese rice grasshopper (Oxya chinensis).jpg|thumb|Chinese rice grasshopper (''[[Oxya chinensis]]'')]]
Rice plants produce their own chemical defenses to protect themselves from pest attacks. Some synthetic chemicals, such as 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.<ref>{{cite journal | vauthors = Xin Z, Yu Z, Erb M, Turlings TC, Wang B, Qi J, Liu S, Lou Y | display-authors = 6 | title = The broad-leaf herbicide 2,4-dichlorophenoxyacetic acid turns rice into a living trap for a major insect pest and a parasitic wasp | journal = The New Phytologist | volume = 194 | issue = 2 | pages = 498–510 | date = April 2012 | pmid = 22313362 | doi = 10.1111/j.1469-8137.2012.04057.x | doi-access = free }}</ref> Conversely, other chemicals, such as the insecticide [[imidacloprid]], can induce changes in the gene expression of the rice that cause the plant to become more susceptible to attacks by certain types of pests.<ref>{{cite journal | vauthors = Cheng Y, Shi ZP, Jiang LB, Ge LQ, Wu JC, Jahn GC | title = Possible connection between imidacloprid-induced changes in rice gene transcription profiles and susceptibility to the brown plant hopper Nilaparvatalugens Stål (Hemiptera: Delphacidae) | journal = Pesticide Biochemistry and Physiology | volume = 102-531 | issue = 3 | pages = 213–219 | date = March 2012 | pmid = 22544984 | pmc = 3334832 | doi = 10.1016/j.pestbp.2012.01.003 }}</ref> 5-[[Alkylresorcinol]]s are chemicals that can also be found in rice.<ref>{{cite journal | vauthors = Suzuki Y, Kurano M, Esumi Y, Yamaguchi I, Doi Y | title = Biosynthesis of 5-alkylresorcinol in rice: incorporation of a putative fatty acid unit in the 5-alkylresorcinol carbon chain | journal = Bioorganic Chemistry | volume = 31 | issue = 6 | pages = 437–452 | date = December 2003 | pmid = 14613765 | doi = 10.1016/j.bioorg.2003.08.003 }}</ref>


Rice yield can be reduced by weed growth, and a wide variety of pests including insects, nematodes, rodents such as rats, snails, and birds.<ref name="IRRI Pests and diseases">{{cite web |title=Pests and diseases management |url=http://www.knowledgebank.irri.org/training/fact-sheets/pest-management |publisher=[[International Rice Research Institute]] |access-date=January 4, 2024}}</ref> Major rice insect pests include armyworms, [[rice bug]]s, [[Scotinophara|black bugs]], cutworms, field crickets, grasshoppers, leafhoppers, mealybugs, and planthoppers.<ref name="IRRI Insects">{{cite web |title=Insects |url=http://www.knowledgebank.irri.org/training/fact-sheets/pest-management/insects |publisher=[[International Rice Research Institute]] |access-date=January 4, 2024}}</ref> High rates of [[nitrogen fertiliser]] application may worsen aphid outbreaks.<ref name="Jahn Almazan 2005">{{cite journal |last1=Jahn |first1=Gary C. |last2=Almazan |first2=Liberty P. |last3=Pacia |first3=Jocelyn B. |doi=10.1603/0046-225X-34.4.938 |title=Effect of Nitrogen Fertilizer on the Intrinsic Rate of Increase of ''Hysteroneura setariae'' (Thomas) (Homoptera: Aphididae) on Rice (''Oryza sativa'' L.) |year=2005 |s2cid=1941852 |journal=[[Environmental Entomology]] |volume=34 |issue=4 |page=938 |doi-access=free}}</ref>
Botanicals, so-called "natural pesticides", are used by some farmers in an attempt to control rice pests. Botanicals include extracts of leaves, or a mulch of the leaves themselves. Some upland rice farmers in Cambodia spread chopped leaves of the bitter bush (''[[Chromolaena odorata]]'') over the surface of fields after planting. This 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.<ref>{{cite report | vauthors = Jahn GC, Pol C, Khiev B, Pheng S, Chhorn N | date =1999 | title = Farmer's pest management and rice production practices in Cambodian upland and deepwater rice. | work = Cambodia-IRRI-Australia Project, Baseline Survey Rpt No. 7 }}</ref>
Weather conditions can contribute to pest outbreaks: [[Orseolia oryzae|rice gall midge]] outbreaks are worsened by high rainfall in the wet season, while [[Stenchaetothrips biformis|thrips]] outbreaks are associated with drought.<ref>{{cite book |last1=Douangboupha |first1=B. |last2=Khamphoukeo |first2=K. |last3=Inthavong |first3=S. |last4=Schiller |first4=J.M. |last5=Jahn |first5=G.C. |date=2006 |chapter-url=http://aciar.gov.au/files/node/756/Rice%20In%20Laos%20chapter%2016-25.pdf |chapter=Chapter 17: Pests and diseases of the rice production systems of Laos |archive-url=https://web.archive.org/web/20120403052249/http://aciar.gov.au/files/node/756/Rice%20In%20Laos%20chapter%2016-25.pdf |archive-date=April 3, 2012 |pages=265–281 |editor-last=Schiller |editor-first=J.M. |editor2=Chanphengxay, M.B. |editor3=Linquist, B. |editor4=Rao, S.A. |title=Rice in Laos |publisher=[[International Rice Research Institute]] |location=[[Los Baños, Philippines]] |isbn=978-971-22-0211-7 }}</ref>
[[File:Chloroxylon from India.JPG|thumb|Chloroxylon is used for pest management in organic cultivation in [[Chhattisgarh, India|Chhattisgarh]]]]


{{main|:Category:Insect pests of rice}}
Among rice cultivars, there are differences in the responses to, and recovery from, pest damage.<ref name=j1>{{cite journal | vauthors = Jahn GC, Domingo I, Almazan ML, Pacia J | title = Effect of rice bug Leptocorisa oratorius (Hemiptera: Alydidae) on rice yield, grain quality, and seed viability | journal = Journal of Economic Entomology | volume = 97 | issue = 6 | pages = 1923–1927 | date = December 2004 | pmid = 15666746 | doi = 10.1603/0022-0493-97.6.1923 | s2cid = 23278521 }}</ref><ref>{{cite journal |vauthors=Jahn GC, Bunnarith K, Chanty P, Nel C |title=Effects of simulated pest damage on rice yields |url=http://www.mendeley.com/research/effects-of-simulated-pest-damage-on-rice-yields/ |archive-url=https://archive.today/20121203044018/http://www.mendeley.com/research/effects-of-simulated-pest-damage-on-rice-yields/ |url-status=dead |archive-date=December 3, 2012 |journal=IRRN |volume=25 |issue=3 |pages=27–28 |year=2000 |access-date=May 13, 2012 }}</ref><ref name="LSU-AgCenter-varieties-2021" /> Many rice varieties have been selected for resistance to insect pests.<ref>{{cite book | vauthors = Brar DS, Khush GS | chapter = Utilization of Wild Species of Genus ''Oryza'' in Rice Improvement| title = Monograph on Genus ''Oryza''. Plymouth | veditors = Nanda JS, Sharma SD | publisher = [[Science Publishers]] | location = [[Enfield, UK]] | date = 2003 | pages = 283–309 }}</ref><ref>{{cite journal | vauthors = Sangha JS, Chen YH, Kaur J, Khan W, Abduljaleel Z, Alanazi MS, Mills A, Adalla CB, Bennett J, Prithiviraj B, Jahn GC, Leung H | display-authors = 6 | title = Proteome Analysis of Rice (''Oryza sativa'' L.) Mutants Reveals Differentially Induced Proteins during Brown Planthopper (''Nilaparvata lugens'') Infestation | journal = [[International Journal of Molecular Sciences]] | volume = 14 | issue = 2 | pages = 3921–3945 | date = February 2013 | pmid = 23434671 | pmc = 3588078 | doi = 10.3390/ijms14023921 | doi-access = free }}</ref><ref name="LSU-AgCenter-varieties-2021" /> Therefore, particular cultivars are recommended for areas prone to certain pest problems.<ref name="LSU-AgCenter-varieties-2021" /> The genetically based ability of a rice variety to withstand pest attacks is called resistance. Three main types of plant resistance to pests are recognized as nonpreference, antibiosis, and tolerance.<ref name=j2/> Nonpreference (or antixenosis) describes host plants which insects prefer to avoid; antibiosis is where insect survival is reduced after the ingestion of host tissue; and tolerance is the capacity of a plant to produce high yield or retain high quality despite [[Home stored product entomology|insect infestation]].<ref>{{cite journal | vauthors = Kogan M, Ortman EF |title=Antixenosis a new term proposed to defined to describe Painter's "non-preference" modality of resistance |journal=Bulletin of the Entomological Society of America |volume=24 |pages=175–76 |year=1978 |doi=10.1093/besa/24.2.175}}</ref>


=== Diseases ===
Over time, the use of pest-resistant rice varieties selects for pests that are able to overcome these mechanisms of resistance. When a rice variety is no longer able to resist pest infestations, resistance is said to have broken down. Rice varieties that can be widely grown for many years in the presence of pests and retain their ability to withstand the pests are said to have durable resistance. Mutants of popular rice varieties are regularly screened by plant breeders to discover new sources of durable resistance.<ref name=j2>{{cite journal | vauthors = Sangha JS, Chen YH, Palchamy K, Jahn GC, Maheswaran M, Adalla CB, Leung H | title = Categories and inheritance of resistance to Nilaparvata lugens (Hemiptera: Delphacidae) in mutants of indica rice 'IR64' | journal = Journal of Economic Entomology | volume = 101 | issue = 2 | pages = 575–583 | date = April 2008 | pmid = 18459427 | doi = 10.1603/0022-0493(2008)101[575:CAIORT]2.0.CO;2 | s2cid = 39941837 }}</ref><ref>{{cite journal | vauthors = Liu L, Van Zanten L, Shu QY, Maluszynski M |title=Officially released mutant varieties in China |journal=Mutat. Breed. Rev |volume=14 |issue=1 |page=64 |year=2004}}
</ref>


{{main|List of rice diseases}}
===Parasitic weeds===
Rice is parasitized by the eudicot weed ''[[Striga hermonthica]]'',<ref>{{cite journal | vauthors = Yoshida S, Maruyama S, Nozaki H, Shirasu K | title = Horizontal gene transfer by the parasitic plant ''Striga hermonthica'' | journal = Science | volume = 328 | issue = 5982 | pages = 1128 | date = May 2010 | pmid = 20508124 | doi = 10.1126/science.1187145 | s2cid = 39376164 | bibcode = 2010Sci...328.1128Y }}</ref> which is of local importance for this crop.


[[File:Rice blast.jpg|thumb|upright|Healthy rice (left) and rice with [[Magnaporthe grisea|rice blast]] ]]
{{ Anchor | Ecotypes | Ecotype | Cultivars | Cultivar }}
==Ecotypes and cultivars==
{{ Main | List of rice cultivars }}
[[File:Rice diversity.jpg|thumb|right|Rice seed collection from [[IRRI]]]]


[[Magnaporthe grisea|Rice blast]], caused by the fungus ''Magnaporthe grisea'', is the most serious disease of growing rice.<ref name="Dean Talbot Ebbole 2005">{{cite journal |display-authors=3 |last1=Dean |first1=Ralph A. |last2=Talbot |first2=Nicholas J. |last3=Ebbole |first3=Daniel J. |last4=Farman |first4=Mark L. |last5=Mitchell |first5=Thomas K. |last6=Orbach |first6=Marc J. |last7=Thon |first7=Michael |last8=Kulkarni |first8=Resham |last9=Xu |first9=Jin-Rong |last10=Pan |first10=Huaqin |title=The genome sequence of the rice blast fungus Magnaporthe grisea |journal=Nature |volume=434 |issue=7036 |pages=980–986 |date=April 2005 |pmid=15846337 |doi=10.1038/nature03449 |doi-access=free |bibcode=2005Natur.434..980D }}</ref>
While most rice is bred for crop quality and productivity, there are varieties selected for characteristics such as texture, smell, and firmness. There are four major categories of rice worldwide: [[Indica rice|indica]], [[japonica rice|japonica]], [[Aromatic rice|aromatic]] and [[glutinous rice|glutinous]]. The different varieties of rice are not considered interchangeable, either in food preparation or agriculture, so as a result, each major variety is a completely separate market from other varieties. It is common for one variety of rice to rise in price while another one drops in price.<ref>{{cite web|url=http://www.ers.usda.gov/briefing/Rice/SpecialArticle/USricemarket.pdf |title=The U.S. Rice Export Market |publisher=[[United States Department of Agriculture|USDA]] |date=November 2000 |url-status=dead |archive-url=https://web.archive.org/web/20150113063236/http://www.ers.usda.gov/briefing/Rice/SpecialArticle/USricemarket.pdf |archive-date=January 13, 2015}}</ref>
It and [[bacterial leaf streak]] (caused by [[Xanthomonas oryzae pv. oryzae|''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.<ref name="Liu Liu Triplett Leach 2014">{{cite journal |last1=Liu |first1=Wende |last2=Liu |first2=Jinling |last3=Triplett |first3=Lindsay |last4=Leach |first4=Jan E. |last5=Wang |first5=Guo-Liang |title=Novel Insights into Rice Innate Immunity Against Bacterial and Fungal Pathogens |journal=Annual Review of Phytopathology |volume=52 |issue=1 |date=August 4, 2014 |doi=10.1146/annurev-phyto-102313-045926 |pages=213–241|pmid=24906128 }}</ref> Other major rice diseases include [[sheath blight]] (caused by ''[[Rhizoctonia solani]]''), false smut (''[[Ustilaginoidea virens]]''), and bacterial panicle blight (''[[Burkholderia glumae]]'').<ref name="Liu Liu Triplett Leach 2014"/> Viral diseases include rice bunchy stunt, rice dwarf, rice [[tungro]], and rice yellow mottle.<ref name="Hibino-1996">{{cite journal |last=Hibino |first=H. |title=Biology and epidemiology of rice viruses |journal=[[Annual Review of Phytopathology]]|volume=34 |issue=1 |pages=249–274 |year=1996 |pmid=15012543 |doi=10.1146/annurev.phyto.34.1.249 |publisher=[[Annual Reviews (publisher)|Annual Reviews]] }}</ref>


=== Pest management ===
Rice cultivars also fall into groups according to environmental conditions, season of planting, and season of harvest, called ecotypes. Some major groups are the Japan-type (grown in Japan), "buly" and "tjereh" types (Indonesia); ''sali'' (or ''aman''—main winter crop), ''ahu'' (also ''aush'' or ''ghariya'', summer), and ''boro'' (spring) (Bengal and Assam).<ref>{{cite journal | vauthors = Morinaga T |year=1968 |title=Origin and geographical distribution of Japanese rice |journal=Trop. Agric. Res. Ser. |volume=3 |pages=1–15 |url=http://www.jircas.affrc.go.jp/english/publication/jarq/03-2/03-2-001-005.pdf |access-date=February 15, 2014 |archive-url=https://web.archive.org/web/20130105104544/http://www.jircas.affrc.go.jp/english/publication/jarq/03-2/03-2-001-005.pdf |archive-date=January 5, 2013 |url-status=live}}</ref><ref name=Banglapedia>{{cite book | vauthors = Kabir SM |year=2012 |chapter=Rice |chapter-url=http://en.banglapedia.org/index.php?title=Rice | veditors = Islam S, Jamal AA |editor1-link=Sirajul Islam|title=Banglapedia: National Encyclopedia of Bangladesh |edition=Second |publisher=[[Asiatic Society of Bangladesh]]}}</ref> Cultivars exist that are adapted to deep flooding, and these are generally called "floating rice".<ref>{{cite web | url = http://www.cgiar.org/impact/research/rice.html | title = Rice | archive-url = https://web.archive.org/web/20120516011255/http://www.cgiar.org/impact/research/rice.html | archive-date = May 16, 2012 | work = Cgiar.org | access-date = May 13, 2012 }}</ref>


{{further|Integrated pest management|rice-duck farming}}
The largest collection of rice cultivars is at the [[International Rice Research Institute]]<ref>{{cite web |url=http://www.irri.org |title=Home |publisher=Irri.org |access-date=August 13, 2012 |archive-url=https://web.archive.org/web/20110224230656/http://irri.org/ |archive-date=February 24, 2011 |url-status=live}}</ref> in the Philippines, with over 100,000 rice accessions<ref>{{cite web | url = http://irri.org/index.php?option=com_k2&view=item&id=9960&lang=en | title = The International Rice Genebank – conserving rice | work = IRRI.org | archive-url = https://web.archive.org/web/20121023054703/http://irri.org/index.php?option=com_k2&view=item&id=9960&lang=en | archive-date = October 23, 2012 }}</ref> held in the International Rice Genebank.<ref>{{cite journal | vauthors = Jackson MT | title = Conservation of rice genetic resources: the role of the International Rice Genebank at IRRI | journal = Plant Molecular Biology | volume = 35 | issue = 1–2 | pages = 61–67 | date = September 1997 | pmid = 9291960 | doi = 10.1023/A:1005709332130 | s2cid = 3360337 }}</ref> Rice [[cultivar]]s are often classified by their grain shapes and texture. For example, Thai [[Jasmine rice]] is long-grain and relatively less sticky, as some long-grain rice contains less [[amylopectin]] than short-grain cultivars. Chinese restaurants often serve long-grain as plain unseasoned steamed rice though short-grain rice is common as well. Japanese [[mochigome|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 rice|Japanese table rice]] is a sticky, short-grain rice. Japanese [[sake]] rice is another kind as well.


[[Crop protection]] scientists are developing [[Sustainable agriculture|sustainable]] techniques for managing rice pests.<ref name="Jahn Khiev Pol 2001">{{cite book |last1=Jahn |first1=Gary C. |author2=Khiev, B. |author3=Pol, C. |author4=Chhorn, N. |author5=Pheng, S. |author6=Preap, V. |date=2001 |chapter=Developing sustainable pest management for rice in Cambodia |pages=243–258 |editor1=Suthipradit, S. |editor2=Kuntha, C. |editor3=Lorlowhakarn, S. |editor4=Rakngan, J. |title=Sustainable Agriculture: Possibility and Direction |location=Bangkok (Thailand) |publisher=National Science and Technology Development Agency }}</ref> Sustainable pest management is based on four principles: biodiversity, host plant resistance, landscape ecology, and hierarchies in a landscape—from biological to social.<ref name="Savary Horgan Willocquet 2012">{{cite journal |last1=Savary |first1=S. |last2=Horgan |first2=F. |last3=Willocquet |first3=L. |last4=Heong |title=A review of principles for sustainable pest management in rice |year=2012 |journal=Crop Protection |volume=32 |page=54 |doi=10.1016/j.cropro.2011.10.012|bibcode=2012CrPro..32...54S }}</ref> Farmers' pesticide applications are often unnecessary.<ref>{{cite web |url=http://www.scidev.net/Features/index.cfm?fuseaction=readfeatures&itemid=306&language=1 |title=Bangladeshi farmers banish insecticides |work=SCIDEV.net |date=July 30, 2004 |access-date=May 13, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20080126115934/http://www.scidev.net/Features/index.cfm?fuseaction=readfeatures&itemid=306&language=1 |archive-date=January 26, 2008 }}</ref> Pesticides may actually induce [[resurgence (pest)|resurgence]] of populations of rice pests such as the [[brown planthopper]], both by destroying beneficial insects and by enhancing the pest's reproduction.<ref name="Wu Ge Liu Song 2020">{{cite journal |last1=Wu |first1=Jincai |last2=Ge |first2=Linquan |last3=Liu |first3=Fang |last4=Song |first4=Qisheng |last5=Stanley |first5=David |title=Pesticide-Induced Planthopper Population Resurgence in Rice Cropping Systems |journal=Annual Review of Entomology |volume=65 |issue=1 |date=January 7, 2020 |doi=10.1146/annurev-ento-011019-025215 |pages=409–429 |pmid=31610135 |s2cid=204702698 }}</ref> 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.<ref name="Hamilton 2008">{{cite web |title=The pesticide paradox |last=Hamilton |first=Henry Sackville |publisher=[[International Rice Research Institute]] |date=January 18, 2008 |url=http://irri.org/knowledge/publications/rice-today/special-reports/science-shorts/the-pesticide-paradox |archive-url=https://web.archive.org/web/20120119053923/http://irri.org/knowledge/publications/rice-today/special-reports/science-shorts/the-pesticide-paradox |archive-date=January 19, 2012}}</ref>
Indian rice cultivars include long-grained and aromatic [[Basmati]] (ਬਾਸਮਤੀ) (grown in the North), long and medium-grained [[Patna rice]], and in South India ([[Andhra Pradesh]] and [[Karnataka]]) short-grained [[Sona Masuri]] (also called as Bangaru theegalu). In the state of Tamil Nadu, the most prized cultivar is [[Ponni Rice|''ponni'']] which is primarily grown in the delta regions of the [[Kaveri]] River. [[Kaveri]] is also referred to as ponni in the South and the name reflects the geographic region where it is grown. In the Western Indian state of [[Maharashtra]], a short grain variety called [[Ambemohar]] is very popular. This rice has a characteristic fragrance of Mango blossom.


[[File:Penggembala Bebek.jpg|thumb|left|A farmer [[Rice-duck farming|grazes his ducks]] in [[paddy field]]s, Central Java]]
Aromatic rices have definite aromas and flavors; the most noted cultivars are Thai fragrant rice, Basmati, Patna rice, Vietnamese fragrant rice, and a [[Hybrid (biology)|hybrid]] cultivar from America, sold under the trade name Texmati. Both Basmati and Texmati have a mild [[popcorn]]-like aroma and flavor. In Indonesia, there are also ''red'' and ''black'' cultivars.


Farmers in China, Indonesia and the Philippines have traditionally managed weeds and pests by the [[polyculture|polycultural]] practice of [[Rice-duck farming|raising ducks]] and [[Rice-fish system|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.<ref name="Bezemer 2022">{{cite web |last=Bezemer |first=Marjolein |date=October 23, 2022 |title=Mixed farming increases rice yield |url=https://www.renature.co/articles/mixed-farming-increase-rice-yield/ |url-status=live |archive-url=https://web.archive.org/web/20191011124422/https://renaturefoundation.nl/2018/12/12/mixed-farming-increase-rice-yield/ |archive-date=October 11, 2019 |access-date=January 2, 2024 |website=reNature Foundation}}</ref><ref name="Cagauan Branckaert Van Hove 2000">{{cite journal |last1=Cagauan |first1=A. G. |last2=Branckaert |first2=R. D. |last3=Van Hove |first3=C. |title=Integrating fish and azolla into rice-duck farming in Asia |journal=Naga (ICLARM Quarterly) |volume=23 |issue=1 |pages=4–10 |year=2000 |url=https://aquadocs.org/bitstream/handle/1834/25720/na_2359.pdf?sequence=1&isAllowed=y}}</ref>
High-yield cultivars of rice suitable for cultivation in Africa and other dry [[ecosystems]], called the [[New Rice for Africa|new rice for Africa]] (NERICA) cultivars, have been developed. It is hoped that their cultivation will improve [[food security]] in West Africa.


Rice plants produce their own chemical defences to protect themselves from pest attacks. Some synthetic chemicals, such as the herbicide [[2,4-Dichlorophenoxyacetic acid|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.<ref name="Xin Yu Erb 2012">{{cite journal |last1=Xin |first1=Zhaojun |last2=Yu |first2=Zhaonan |last3=Erb |first3=Matthias |last4=Turlings |first4=Ted C. J. |last5=Wang |first5=Baohui |last6=Qi |first6=Jinfeng |last7=Liu |first7=Shengning |last8=Lou |first8=Yonggen |display-authors=5 |title=The broad-leaf herbicide 2,4-dichlorophenoxyacetic acid turns rice into a living trap for a major insect pest and a parasitic wasp |journal=The New Phytologist |volume=194 |issue=2 |pages=498–510 |date=April 2012 |pmid=22313362 |doi=10.1111/j.1469-8137.2012.04057.x |doi-access= }}</ref> 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.<ref name="Cheng Shi Jiang 2012">{{cite journal |last1=Cheng |first1=Yao |last2=Shi |first2=Zhao-Peng |last3=Jiang |first3=Li-Ben |last4=Ge |first4=Lin-Quan |last5=Wu |first5=Jin-Cai |last6=Jahn |first6=Gary C. |title=Possible connection between imidacloprid-induced changes in rice gene transcription profiles and susceptibility to the brown plant hopper Nilaparvatalugens Stål (Hemiptera: Delphacidae) |journal=Pesticide Biochemistry and Physiology |volume=102 |issue=3 |pages=213–219 |date=March 2012 |pmid=22544984 |pmc=3334832 |doi=10.1016/j.pestbp.2012.01.003 |bibcode=2012PBioP.102..213C }}</ref>
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.<ref>{{cite news | vauthors = Gillis J | title=Rice Genome Fully Mapped | date=August 11, 2005 | newspaper=Washington Post | url=https://www.washingtonpost.com/wp-dyn/content/article/2005/08/10/AR2005081001054.html | access-date=September 10, 2017 | archive-url=https://web.archive.org/web/20170330212346/http://www.washingtonpost.com/wp-dyn/content/article/2005/08/10/AR2005081001054.html | archive-date=March 30, 2017 | url-status=live}}</ref>


Plant breeders have created rice cultivars incorporating [[plant resistance to insects|resistance to various insect pests]]. Conventional plant breeding of resistant varieties has been limited by challenges such as rearing insect pests for testing, and 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.<ref name="Makkar Bhatia Suri Kaur 2019">{{cite journal |last1=Makkar |first1=Gurpreet Singh |last2=Bhatia |first2=Dharminder |last3=Suri |first3=K.S. |last4=Kaur |first4=Simranjeet |title=Insect resistance in Rice (Oryza sativa L.): overview on current breeding interventions |journal=International Journal of Tropical Insect Science |volume=39 |issue=4 |date=2019 |doi=10.1007/s42690-019-00038-1 |pages=259–272|s2cid=202011174 }}</ref>
On December 16, 2002, the [[UN General Assembly]] declared the year 2004 the International Year of Rice. The declaration was sponsored by more than 40 countries.


{{Anchor|Ecotypes|Ecotype|Cultivars|Cultivar}}
[[Varietal development]] has ceremonial and historical significance for some cultures (see {{ Section link || Culture }} below). The [[King of Thailand|Thai kings]] have patronised rice breeding since at least the reign of [[Chulalongkorn]],<ref name="Thai-Min-Ag-hist">{{cite web | title=History | trans-website=[[Ministry of Agriculture and Cooperatives (Thailand)|Ministry of Agriculture and Cooperatives]] | website=กระทรวงเกษตรและสหกรณ์ | url=http://www.moac.go.th/moaceng-history | access-date=August 30, 2021 | archive-date=November 17, 2021 | archive-url=https://web.archive.org/web/20211117010531/https://www.moac.go.th/moaceng-history | url-status=dead }}</ref><ref name="FFTC-AP-rice-breeding">{{cite web | title=Rice Breeding and R&D Policies in Thailand | website=[[Food and Fertilizer Technology Center]] Agricultural Policy Platform (FFTC-AP) | date=April 26, 2018 | url=http://ap.fftc.org.tw/article/1278 | access-date=August 30, 2021}}</ref> and his great-great-grandson [[Vajiralongkorn]] released five particular rice varieties to celebrate [[Coronation of Vajiralongkorn|his coronation]].<ref name="Vajiralongkorn-coron">{{cite web | title=Five rice varieties launched in honour of Royal Coronation | website=[[The Nation (Thailand)|The Nation]] | date=May 7, 2019 | url=http://www.nationthailand.com/in-focus/30369003 | access-date=August 21, 2021}}</ref>


==Ecotypes and cultivars==
== Biotechnology ==


{{ Main |List of rice cultivars }}
=== High-yielding varieties ===


[[File:Rice diversity.jpg|thumb|upright=0.9|Rice seed collection from [[IRRI]] ]]
The high-yielding varieties are a group of crops created intentionally during the [[Green Revolution]] to increase global food production. This project enabled labor markets in Asia to shift away from agriculture, and into industrial sectors. The first "Rice Car", [[IR8]] was produced in 1966 at the [[International Rice Research Institute]] which is based in the Philippines at the [[University of the Philippines]]' Los Baños site. IR8 was created through a cross between an Indonesian variety named "Peta" and a Chinese variety named "Dee Geo Woo Gen."<ref name="ir8">{{cite web|url=http://www.knowledgebank.irri.org/regionalSites/nepal/RiceVarieties.htm |title=Rice Varieties |access-date=July 13, 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060713032524/http://www.knowledgebank.irri.org/regionalSites/nepal/RiceVarieties.htm |archive-date=July 13, 2006}}. IRRI Knowledge Bank.</ref>


The [[International Rice Research Institute]] maintains the International Rice Genebank, which holds over 100,000 rice varieties.<ref>{{cite web |url=http://irri.org/index.php?option=com_k2&view=item&id=9960&lang=en |title=The International Rice Genebank – conserving rice |publisher=[[International Rice Research Institute]] |archive-url=https://web.archive.org/web/20121023054703/http://irri.org/index.php?option=com_k2&view=item&id=9960&lang=en |archive-date=October 23, 2012 }}</ref><ref>{{cite journal |last=Jackson |first=M. T. |title=Conservation of rice genetic resources: the role of the International Rice Genebank at IRRI |journal=[[Plant Molecular Biology]] |volume=35 |issue=1–2 |pages=61–67 |date=September 1997 |pmid=9291960 |doi=10.1023/A:1005709332130 |s2cid=3360337 }}</ref> Much of southeast Asia grows [[sticky rice|sticky]] or glutinous rice varieties.<ref name="Sattaka 2016">{{Cite journal |last=Sattaka |first=Patcha |date=December 27, 2016 |title=Geographical Distribution of Glutinous Rice in the Greater Mekong Sub-region |url=https://so03.tci-thaijo.org/index.php/mekongjournal/article/view/73311 |journal=Journal of Mekong Societies |language=en |volume=12 |issue=3 |pages=27–48}}</ref> High-yield cultivars of rice suitable for cultivation in Africa, called the [[New Rice for Africa]] (NERICA), have been developed to improve [[food security]] and alleviate poverty in Sub-Saharan Africa.<ref>{{cite web |title=NERICA: Rice for Life |publisher=[[Africa Rice Center]] (WARDA) |year=2001 |url=http://www.warda.cgiar.org/publications/NERICA8.pdf |archive-url=https://web.archive.org/web/20031204153208/http://www.warda.cgiar.org/publications/NERICA8.pdf |url-status=dead |archive-date=December 4, 2003 |accessdate=July 7, 2008}}</ref>
Scientists have identified and cloned many genes involved in the [[gibberellin]] signaling pathway, including GAI1 ([[Gibberellin]] Insensitive) and SLR1 (Slender Rice).<ref>{{cite journal | vauthors = Yamaguchi S | title = Gibberellin metabolism and its regulation | journal = Annual Review of Plant Biology | volume = 59 | issue = 1 | pages = 225–251 | year = 2008 | pmid = 18173378 | doi = 10.1146/annurev.arplant.59.032607.092804 }}</ref> Disruption of [[gibberellin]] signaling can lead to significantly reduced stem growth leading to a dwarf phenotype. Photosynthetic investment in the stem is reduced dramatically as the shorter plants are inherently more stable mechanically. Assimilates become redirected to grain production, amplifying in particular the effect of chemical fertilizers on commercial yield. In the presence of nitrogen fertilizers, and intensive crop management, these varieties increase their yield two to three times.


The complete [[genome]] of rice was [[Whole genome sequencing|sequenced]] in 2005, making it the first crop plant to reach this status.<ref name="Gillis 2005">{{cite news |last=Gillis |first=J. |title=Rice Genome Fully Mapped |date=August 11, 2005 |newspaper=[[The Washington Post]] |url=https://www.washingtonpost.com/wp-dyn/content/article/2005/08/10/AR2005081001054.html |access-date=September 10, 2017 |archive-url=https://web.archive.org/web/20170330212346/http://www.washingtonpost.com/wp-dyn/content/article/2005/08/10/AR2005081001054.html |archive-date=March 30, 2017 |url-status=live}}</ref>
=== Future potential ===
Since then, the genomes of hundreds of types of rice, both wild and cultivated, and including both Asian and African rice species, have been sequenced.<ref>{{Cite journal |last1=Shang |first1=Lianguang |last2=Li |first2=Xiaoxia |last3=He |first3=Huiying |last4=Yuan |first4=Qiaoling |last5=Song |first5=Yanni |last6=Wei |first6=Zhaoran |last7=Lin |first7=Hai |last8=Hu |first8=Min |last9=Zhao |first9=Fengli |last10=Zhang |first10=Chao |last11=Li |first11=Yuhua |last12=Gao |first12=Hongsheng |last13=Wang |first13=Tianyi |last14=Liu |first14=Xiangpei |last15=Zhang |first15=Hong |display-authors=5 |date=2022 |title=A super pan-genomic landscape of rice |journal=[[Cell Research]] |volume=32 |issue=10 |pages=878–896 |doi=10.1038/s41422-022-00685-z |pmc=9525306 |pmid=35821092}}</ref>
{{ Update section | reason=gene editing? low ghg emissions? | date=October 2021 }}
As the UN Millennium Development project seeks to spread global economic development to Africa, the "Green Revolution" is cited as the model for economic development. With the intent of replicating the successful Asian boom in agronomic productivity, groups like the [[Earth Institute]] are doing research on African agricultural systems, hoping to increase productivity. An important way this can happen is the production of "[[New Rices for Africa]]" (NERICA). These rices, selected to tolerate the low input and harsh growing conditions of African agriculture, are produced by the African Rice Center, and billed as technology "from Africa, for Africa". The NERICA have appeared in ''The New York Times'' (October 10, 2007) and ''International Herald Tribune'' (October 9, 2007), trumpeted as miracle crops that will dramatically increase rice yield in Africa and enable an economic resurgence. Ongoing research in China to develop [[perennial rice]] could result in enhanced sustainability and [[food security]].


=== Golden rice ===
== Biotechnology ==

{{ Excerpt | Golden rice }}
=== High-yielding varieties ===

{{main|Green revolution}}

The high-yielding varieties are a group of crops created during the [[Green Revolution]] to increase global food production radically. The first Green Revolution rice variety, [[IR8]], was produced in 1966 at the [[International Rice Research Institute]] through a cross between an Indonesian variety named "Peta" and a Chinese variety named "Dee Geo Woo Gen".<ref name="Hettel 2016">{{cite web |last=Hettel |first=Gene |title=IR8—a rice variety for the ages |url=https://ricetoday.irri.org/ir8-a-rice-variety-for-the-ages/ |website=Rice Today |access-date=December 29, 2023 |date=November 18, 2016}}</ref> Green Revolution varieties were bred to have short strong stems so that the rice would not lodge or fall over. This enabled them to stay upright and productive even with heavy applications of fertiliser.<ref name="Hettel 2016"/>


=== Expression of human proteins ===
=== Expression of human proteins ===


[[Ventria Bioscience]] has [[genetically modified]] rice to [[gene expression|express]] [[lactoferrin]], [[lysozyme]] which are [[proteins]] usually found in [[breast milk]], and [[human serum albumin]], These proteins have [[Antiviral protein|antiviral]], [[antibacterial]], and [[Antifungal protein|antifungal]] effects.<ref>{{cite journal|doi=10.1038/news070514-17 |journal=Nature |title=Rice with human proteins to take root in Kansas | vauthors = Marris E |s2cid=84688423 |date=May 18, 2007}}</ref>
[[Ventria Bioscience]] has [[genetically modified]] rice to [[gene expression|express]] [[lactoferrin]] and [[lysozyme]] which are [[proteins]] usually found in [[breast milk]], and [[human serum albumin]]. These proteins have [[Antiviral protein|antiviral]], [[antibacterial]], and [[Antifungal protein|antifungal]] effects.<ref>{{cite journal |last=Marris |first=E. |title=Rice with human proteins to take root in Kansas |journal=Nature |date=May 18, 2007 |s2cid=84688423 |doi=10.1038/news070514-17}}</ref> Rice containing these added proteins can be used as a component in [[oral rehydration solution]]s to treat [[diarrhea]]l diseases, thereby shortening their duration and reducing recurrence. Such supplements may also help reverse [[anemia]].<ref>{{cite journal |last1=Bethell |first1=D.R. |last2=Huang |first2=J. |title=Recombinant human lactoferrin treatment for global health issues: iron deficiency and acute diarrhea |journal=Biometals |volume=17 |issue=3 |pages=337–342 |date=June 2004 |pmid=15222487 |doi=10.1023/B:BIOM.0000027714.56331.b8 |s2cid=3106602 }}</ref>


=== Flood-tolerance ===
Rice containing these added proteins can be used as a component in [[oral rehydration solution]]s which are used to treat [[diarrhea]]l diseases, thereby shortening their duration and reducing recurrence. Such supplements may also help reverse [[anemia]].<ref>{{cite journal | vauthors = Bethell DR, Huang J | title = Recombinant human lactoferrin treatment for global health issues: iron deficiency and acute diarrhea | journal = Biometals | volume = 17 | issue = 3 | pages = 337–342 | date = June 2004 | pmid = 15222487 | doi = 10.1023/B:BIOM.0000027714.56331.b8 | s2cid = 3106602 }}</ref>


{{Main|Deepwater rice}}
===Flood-tolerant rice===
{{ Main | Deepwater rice }}
Due to the varying levels that water can reach in regions of cultivation, [[Deepwater rice|flood tolerant varieties]] have long been developed and used. [[Flooding]] is an issue that many rice growers face, especially in South and [[South East Asia]] where flooding annually affects {{convert|20|e6ha|e6acre|abbr=off}}.<ref name="Debrata-2012">{{cite journal | vauthors = Debrata P, Sarkar RK | year = 2012 | title = Role of Non-Structural Carbohydrate and its Catabolism Associated with Sub 1 QTL in Rice Subjected to Complete Submergence | journal = Experimental Agriculture | volume = 48 | issue = 4| pages = 502–12 | doi = 10.1017/S0014479712000397| s2cid = 86192842 }}</ref> Standard rice varieties cannot withstand stagnant flooding of more than about a week,<ref>{{cite web | url = http://www.thehindu.com/sci-tech/agriculture/swarna-sub1-flood-resistant-rice-variety/article2494126.ece | title = Swarna Sub1: flood resistant rice variety | archive-url = https://web.archive.org/web/20131102193934/http://www.thehindu.com/sci-tech/agriculture/swarna-sub1-flood-resistant-rice-variety/article2494126.ece | archive-date = November 2, 2013 | work = The Hindu | date = 2011 | access-date = October 31, 2013 }}</ref> mainly as it disallows the plant access to necessary requirements such as sunlight and essential gas exchanges, inevitably leading to plants being unable to recover.<ref name="Debrata-2012" />
In the past, this has led to massive losses in yields, such as in the [[Philippines]], where in 2006, rice crops worth $65&nbsp;million were lost to flooding.<ref name="IRRI-2012">"{{cite web | url = http://irri.org/index.php?option=com_k2&view=item&id=9148&lang=en | title = Climate change-ready rice | archive-url = https://web.archive.org/web/20121028234824/http://irri.org/index.php?option=com_k2&view=item&id=9148&lang=en | archive-date = October 28, 2012 | work = International Rice Research Institute (IRRI) | access-date = October 31, 2013 }}</ref> Recently developed cultivars seek to improve flood tolerance.


[[File:Researchers checking deep water rice.jpg|thumb|upright=1.2|International Rice Research Institute researchers checking [[deepwater rice]] in the Philippines ]]
===Drought-tolerant rice===


In areas subject to [[flooding]], farmers have long planted flood tolerant varieties known as [[deepwater rice]]. In South and [[South East Asia]], flooding affects some {{convert|20|e6ha|e6acre|abbr=off}} each year.<ref name="Debrata-2012">{{cite journal |last1=Debrata |first1=Panda |last2=Sarkar |first2=Ramani Kumar |year=2012 |title=Role of Non-Structural Carbohydrate and its Catabolism Associated with Sub 1 QTL in Rice Subjected to Complete Submergence |journal=Experimental Agriculture |volume=48 |issue=4|pages=502–512 |doi=10.1017/S0014479712000397 |s2cid=86192842 }}</ref>
[[Drought]] represents a significant environmental stress for rice production, with {{convert|19-23|e6ha|e6acre|abbr=off}} of rainfed rice production in South and South East Asia often at risk.<ref name="irri.org">{{cite web | url = http://irri.org/index.php?option=com_k2&view=item&id=9952:drought-submergence-an | title = Drought, submergence and salinity management | archive-url = https://web.archive.org/web/20131101131821/http://irri.org/index.php?option=com_k2&view=item&id=9952%3Adrought-submergence-an | archive-date = November 1, 2013 | work = International Rice Research Institute (IRRI) | access-date = September 29, 2013 }}</ref><ref name="IRRI-2014">"{{cite web | url = http://irri.org/our-work/research/better-rice-varieties/climate-change-ready-rice | title = Climate change-ready rice | archive-url = https://web.archive.org/web/20140314033307/http://irri.org/our-work/research/better-rice-varieties/climate-change-ready-rice | archive-date = March 14, 2014 | work = International Rice Research Institute (IRRI) | access-date = September 29, 2013 }}</ref> Under drought conditions, without sufficient water to afford them the ability to obtain the required levels of [[nutrients]] from the soil, conventional commercial rice varieties can be severely affected—for example, yield losses as high as 40% have affected some parts of India, with resulting losses of around US$800&nbsp;million annually.<ref name="Palmer-2013">{{cite web | url = http://www.ciatnews.cgiar.org/2013/08/06/newly-discovered-rice-gene-goes-to-the-root-of-drought-resistance/ | title = Newly-discovered rice gene goes to the root of drought resistance | archive-url = https://web.archive.org/web/20131103182251/http://www.ciatnews.cgiar.org/2013/08/06/newly-discovered-rice-gene-goes-to-the-root-of-drought-resistance/ | archive-date = November 3, 2013 | vauthors = Palmer N | date = 2013 | access-date = September 29, 2013 }}</ref>
Flooding has historically led to massive losses in yields, such as in the Philippines, where in 2006, rice crops worth $65&nbsp;million were lost to flooding.<ref name="IRRI-2012">"{{cite web |url=http://irri.org/index.php?option=com_k2&view=item&id=9148&lang=en |title=Climate change-ready rice |archive-url=https://web.archive.org/web/20121028234824/http://irri.org/index.php?option=com_k2&view=item&id=9148&lang=en |archive-date=October 28, 2012 |publisher=[[International Rice Research Institute]] |access-date=October 31, 2013 }}</ref>


Standard rice varieties cannot withstand stagnant flooding for more than about a week, since it disallows the plant access to necessary requirements such as sunlight and gas exchange. The Swarna Sub1 cultivar can tolerate week-long submergence, consuming carbohydrates efficiently and continuing to grow.<ref name="Debrata-2012"/> So-called "[[Scuba diving|scuba]] rice"<ref>{{cite web |last1=Gautam |first1=Priyanka |display-authors=etal |title=Nutrient Management for Enhancing Submergence Tolerance in Rice |url=https://krishi.icar.gov.in/jspui/bitstream/123456789/8940/1/Research%20Bulletin-13.pdf |publisher=National Rice Research Institute |location=Cuttack, Odisha, India |page=3 |date=2017 |quote=NRRI Research Bulletin No. 13}}</ref> with the Sub1A [[transgene]] is robustly tolerant of submergence for as long as two weeks, offering much improved flood survival for farmers' crops. IRRI has created Sub1A varieties and distributed them to Bangladesh, India, Indonesia, Nepal, and the Philippines.<ref name="Emerick Ronald 2019">{{cite journal |last1=Emerick |first1=Kyle |last2=Ronald |first2=Pamela C. |title=Sub1 Rice: Engineering Rice for Climate Change |journal=Cold Spring Harbor Perspectives in Biology |volume=11 |issue=12 |date=2019 |pmid=31182543 |pmc=6886445 |doi=10.1101/cshperspect.a034637 |page=a034637}}</ref>
The [[International Rice Research Institute]] conducts research into developing drought-tolerant rice varieties, including the varieties 5411 and Sookha dhan, currently being employed by farmers in the Philippines and Nepal respectively.<ref name="IRRI-2014" /> In addition, in 2013 the Japanese National Institute for Agrobiological Sciences led a team which successfully inserted the DEEPER ROOTING 1 (DRO1) gene, from the Philippine [[Upland and lowland (freshwater ecology)|upland]] rice variety Kinandang Patong, into the popular commercial rice variety IR64, giving rise to a far deeper root system in the resulting plants.<ref name="Palmer-2013" /> This facilitates an improved ability for the rice plant to derive its required nutrients in times of drought via accessing deeper layers of [[soil]], a feature demonstrated by trials which saw the IR64 + DRO1 rice yields drop by 10% under moderate drought conditions, compared to 60% for the unmodified IR64 variety.<ref name="Palmer-2013" /><ref>{{cite web | url = http://phys.org/news/2013-08-roots-breakthrough-drought-resistant-rice.html | title = Roots breakthrough for drought resistant rice | archive-url = https://web.archive.org/web/20131102113839/http://phys.org/news/2013-08-roots-breakthrough-drought-resistant-rice.html | archive-date = November 2, 2013 | work = Phys.org | date = 2013 | access-date = September 30, 2013 }}</ref>


===Salt-tolerant rice===
===Drought-tolerance===


[[Drought]] represents a significant environmental stress for rice production, with {{convert|19-23|e6ha|e6acre|abbr=off}} of rainfed rice production in South and South East Asia often at risk.<ref name="irri.org">{{cite web |url=http://irri.org/index.php?option=com_k2&view=item&id=9952:drought-submergence-an |title=Drought, submergence and salinity management |archive-url=https://web.archive.org/web/20131101131821/http://irri.org/index.php?option=com_k2&view=item&id=9952%3Adrought-submergence-an |archive-date=November 1, 2013 |work=International Rice Research Institute (IRRI) |access-date=September 29, 2013 }}</ref><ref name="IRRI-2014">"{{cite web |url=http://irri.org/our-work/research/better-rice-varieties/climate-change-ready-rice |title=Climate change-ready rice |archive-url=https://web.archive.org/web/20140314033307/http://irri.org/our-work/research/better-rice-varieties/climate-change-ready-rice |archive-date=March 14, 2014 |publisher=[[International Rice Research Institute]] (IRRI) |access-date=September 29, 2013 }}</ref> Under drought conditions, without sufficient water to afford them the ability to obtain the required levels of [[nutrients]] from the soil, conventional commercial rice varieties can be severely affected—as happened for example in India early in the 21st century.<ref name="Palmer-2013">{{cite web |url=http://www.ciatnews.cgiar.org/2013/08/06/newly-discovered-rice-gene-goes-to-the-root-of-drought-resistance/ |title=Newly-discovered rice gene goes to the root of drought resistance |archive-url=https://web.archive.org/web/20131103182251/http://www.ciatnews.cgiar.org/2013/08/06/newly-discovered-rice-gene-goes-to-the-root-of-drought-resistance/ |archive-date=November 3, 2013 |last=Palmer |first=Neil |date=2013 |publisher=[[International Center for Tropical Agriculture]] |access-date=September 29, 2013 }}</ref>
{{ Further | Crop tolerance to seawater }}


The [[International Rice Research Institute]] conducts research into developing drought-tolerant rice varieties, including the varieties Sahbhagi Dhan, Sahod Ulan, and Sookha dhan, currently being employed by farmers in India, the Philippines, and Nepal respectively.<ref name="IRRI-2014" /> In addition, in 2013 the Japanese National Institute for Agrobiological Sciences led a team which successfully inserted the ''DEEPER ROOTING 1'' (''DRO1'') gene, from the Philippine [[Upland and lowland (freshwater ecology)|upland]] rice variety Kinandang Patong, into the popular commercial rice variety IR64, giving rise to a far deeper root system in the resulting plants.<ref name="Palmer-2013" /> This facilitates an improved ability for the rice plant to derive its required nutrients in times of drought via accessing deeper layers of [[soil]], a feature demonstrated by trials which saw the IR64 + DRO1 rice yields drop by 10% under moderate drought conditions, compared to 60% for the unmodified IR64 variety.<ref name="Palmer-2013"/><ref>{{cite web |url=http://phys.org/news/2013-08-roots-breakthrough-drought-resistant-rice.html |title=Roots breakthrough for drought resistant rice |archive-url=https://web.archive.org/web/20131102113839/http://phys.org/news/2013-08-roots-breakthrough-drought-resistant-rice.html |archive-date=November 2, 2013 |work=Phys.org |date=2013 |access-date=September 30, 2013 }}</ref>
[[Soil salinity]] poses a major threat to rice crop productivity, particularly along low-lying coastal areas during the dry season.<ref name="irri.org"/> For example, roughly {{convert|1|e6ha|e6acre|abbr=off}} of the coastal areas of [[Bangladesh]] are affected by saline soils.<ref>"{{cite web | url = http://irri.org/index.php?option=com_k2&view=item&id=10379&Itemid=100242&lang=en | title = Less salt, please | archive-url = https://web.archive.org/web/20131101133710/http://irri.org/index.php?option=com_k2&view=item&id=10379&Itemid=100242&lang=en | archive-date= 1 November 2013 | vauthors = Fredenburg P | date = 2007 | access-date = 30 September 2013 | work = irri.org }}</ref> These high concentrations of salt can severely affect rice plants' normal [[physiology]], especially during early stages of growth, and as such farmers are often forced to abandon these otherwise potentially usable areas.<ref name="IRRI-2013">"{{cite web | url = http://irri.org/index.php?option%3Dcom_k2%26view%3Ditem%26id%3D12537 | title = Wild parent spawns super salt tolerant rice | archive-url = https://web.archive.org/web/20170701113644/http://irri.org/index.php?option=com_k2&view=item&id=12537 | archive-date=July 1, 2017 | work = International Rice Research Institute (IRRI) | date = 2013 | access-date = September 30, 2013 }}</ref><ref>{{cite web | url = http://irri.org/index.php?option=com_k2&view=item&id=12222:do-rice-and-salt-go-together?&Itemid=100242&lang=en | title = Do rice and salt go together? | archive-url = https://web.archive.org/web/20131101134139/http://irri.org/index.php?option=com_k2&view=item&id=12222%3Ado-rice-and-salt-go-together%3F&Itemid=100242&lang=en | archive-date = November 1, 2013 | vauthors = Ferrer B | date = 2012 | access-date = September 30, 2013 | work = irri.org }}</ref>


=== Salt-tolerance ===
Progress has been made, however, in developing rice varieties capable of tolerating such conditions; the hybrid created from the cross between the commercial rice variety IR56 and the wild rice species ''Oryza coarctata'' is one example.<ref name="Integrated Breeding Platform (IBP)-2013">"{{cite web | url = https://www.integratedbreeding.net/news/breakthrough-salt-resistant-rice-research-single-baby-rice-plant-may-hold-future-extending-rice | title = Breakthrough in salt-resistant rice research—single baby rice plant may hold the future to extending rice farming | archive-url = https://web.archive.org/web/20131102081913/https://www.integratedbreeding.net/news/breakthrough-salt-resistant-rice-research-single-baby-rice-plant-may-hold-future-extending-rice | archive-date = November 2, 2013 | work = Integrated Breeding Platform (IBP) | date = 2013 | access-date = October 6, 2013 }}</ref> ''O. coarctata'' is capable of successful growth in soils with double the limit of salinity of normal varieties, but lacks the ability to produce edible rice.<ref name="Integrated Breeding Platform (IBP)-2013" /> Developed by the [[International Rice Research Institute]], the [[Hybrid (biology)|hybrid]] variety can utilise specialised leaf glands that allow for the removal of salt into the atmosphere. It was initially produced from one successful [[embryo]] out of 34,000 crosses between the two species; this was then [[Backcrossing|backcrossed]] to IR56 with the aim of preserving the genes responsible for salt tolerance that were inherited from ''O. coarctata''.<ref name="IRRI-2013" /> Extensive trials are planned prior to the new variety being available to farmers by approximately 2017–18.<ref name="IRRI-2013" />
[[File:rice egypt.png|thumb|upright=1.15|The irrigated rice (paddy) crop in Egypt has a salt tolerance of ECe=5.5 dS/m beyond which the yield declines.<ref>{{cite web | title = On line collection of salt tolerance data of agricultural crops obtained from measurements in farmers' fields | url = https://www.waterlog.info/croptol.htm | archive-url = https://web.archive.org/web/20170824013141/https://www.waterlog.info/croptol.htm | archive-date= August 24, 2017 | work = www.waterlog.info}}</ref>]]


{{further|Crop tolerance to seawater}}
When the problem of [[soil salinity]] arises it will be opportune to select salt tolerant varieties (IRRI<ref>{{cite web | work = [[International Rice Research Institute]] | title = Rice Breeding Course, Breeding for salt tolerance in rice, on line | url = http://www.knowledgebank.irri.org/ricebreedingcourse/Breeding_for_salt_tolerance.htm | archive-url = https://web.archive.org/web/20170505220950/http://www.knowledgebank.irri.org/ricebreedingcourse/Breeding_for_salt_tolerance.htm | archive-date = May 5, 2017 }}</ref> or to resort to [[soil salinity control]].


[[Soil salinity]] poses a major threat to rice crop productivity, particularly along low-lying coastal areas during the dry season.<ref name="irri.org"/><ref>{{cite web |work=[[International Rice Research Institute]] |title=Rice Breeding Course, Breeding for salt tolerance in rice, on line |url= http://www.knowledgebank.irri.org/ricebreedingcourse/Breeding_for_salt_tolerance.htm |archive-url=https://web.archive.org/web/20170505220950/http://www.knowledgebank.irri.org/ricebreedingcourse/Breeding_for_salt_tolerance.htm |archive-date=May 5, 2017 }}</ref> For example, roughly {{convert|1|e6ha|e6acre|abbr=off}} of the coastal areas of [[Bangladesh]] are affected by saline soils.<ref>"{{cite web |url=http://irri.org/index.php?option=com_k2&view=item&id=10379&Itemid=100242&lang=en |title=Less salt, please |archive-url=https://web.archive.org/web/20131101133710/http://irri.org/index.php?option=com_k2&view=item&id=10379&Itemid=100242&lang=en |archive-date= 1 November 2013 |last=Fredenburg |first=P. |date=2007 |access-date=30 September 2013 |publisher=[[International Rice Research Institute]] }}</ref> These high concentrations of salt can severely affect rice plants' [[physiology]], especially during early stages of growth, and as such farmers are often forced to abandon these areas.<ref name="IRRI-2013">"{{cite web |url=https://ricetoday.irri.org/wild-parent-spawns-super-salt-tolerant-rice/ |title=Wild parent spawns super salt tolerant rice | last = Barona-Edna | first = Liz | date = April 15, 2013 | accessdate = January 3, 2024 | work=Rice Today }}</ref>
Soil salinity is often measured as the electric conductivity (EC) of the extract of a saturated soil paste (ECe). The EC units are usually expressed in decisiemens per metre or dS/m. The critical ECe value of 5.5 dS/m in the figure, obtained from measurements in farmers' fields, indicates that the rice crop is slightly salt sensitive.


Progress has been made in developing rice varieties capable of tolerating such conditions; the hybrid created from the cross between the commercial rice variety IR56 and the wild rice species ''Oryza coarctata'' is one example.<ref name="Integrated Breeding Platform (IBP)-2013">"{{cite web |url=https://www.integratedbreeding.net/news/breakthrough-salt-resistant-rice-research-single-baby-rice-plant-may-hold-future-extending-rice |title=Breakthrough in salt-resistant rice research—single baby rice plant may hold the future to extending rice farming |archive-url=https://web.archive.org/web/20131102081913/https://www.integratedbreeding.net/news/breakthrough-salt-resistant-rice-research-single-baby-rice-plant-may-hold-future-extending-rice |archive-date=November 2, 2013 |work=Integrated Breeding Platform (IBP) |date=2013 |access-date=October 6, 2013 }}</ref> ''O. coarctata'' can grow in soils with double the limit of salinity of normal varieties, but does not produce edible rice.<ref name="Integrated Breeding Platform (IBP)-2013"/> Developed by the [[International Rice Research Institute]], the [[Hybrid (biology)|hybrid]] variety utilises specialised leaf glands that remove salt into the atmosphere. It was produced from one successful [[embryo]] out of 34,000 crosses between the two species; this was then [[Backcrossing|backcrossed]] to IR56 with the aim of preserving the genes responsible for salt tolerance that were inherited from ''O. coarctata''.<ref name="IRRI-2013"/>
===Environment-friendly rice===


=== Cold tolerance ===
Producing rice in [[Paddy field|paddies]] is harmful for the environment due to the release of methane by [[Methanogen|methanogenic bacteria]]. These bacteria live in the anaerobic waterlogged soil, and live off nutrients released by rice roots. Researchers have recently reported in ''Nature'' that putting the [[barley]] gene SUSIBA2 into rice creates a shift in biomass production from root to shoot (above ground tissue becomes larger, while below ground tissue is reduced), decreasing the methanogen population, and resulting in a reduction of methane emissions of up to 97%. Apart from this environmental benefit, the modification also increases the amount of rice grains by 43%, which makes it a useful tool in feeding a growing world population.<ref>{{cite journal | vauthors = Su J, Hu C, Yan X, Jin Y, Chen Z, Guan Q, Wang Y, Zhong D, Jansson C, Wang F, Schnürer A, Sun C | display-authors = 6 | title = Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice | journal = Nature | volume = 523 | issue = 7562 | pages = 602–606 | date = July 2015 | pmid = 26200336 | doi = 10.1038/nature14673 | s2cid = 4454200 | bibcode = 2015Natur.523..602S }}</ref><ref>{{cite web| vauthors = Gerry C |title=Feeding the World One Genetically Modified Tomato at a Time: A Scientific Perspective|url=http://sitn.hms.harvard.edu/flash/2015/feeding-the-world/|website=SITN|access-date=September 11, 2015|date=August 9, 2015|archive-url=https://web.archive.org/web/20150910164510/http://sitn.hms.harvard.edu/flash/2015/feeding-the-world/|archive-date=September 10, 2015|url-status=live}}</ref>


Rice is sensitive to temperatures below 12C. Sowing takes place once the daily average temperature is reliably above this limit. Average temperatures below that reduce growth; if sustained for over four days, germination and seedling growth are harmed and seedlings may die. In larger plants subjected to cold, rice blast is encouraged, seriously reducing yield. As of 2022, researchers continue to study the mechanisms of chilling tolerance in rice and its genetic basis.<ref name="Li Zhang Chong 2022">{{cite journal | last1=Li | first1=Junhua | last2=Zhang | first2=Zeyong | last3=Chong | first3=Kang | last4=Xu | first4=Yunyuan | title=Chilling tolerance in rice: Past and present | journal=Journal of Plant Physiology | volume=268 | date=2022 | doi=10.1016/j.jplph.2021.153576 | page=153576| pmid=34875419 | bibcode=2022JPPhy.26853576L }}</ref>
==Meiosis and DNA repair==


=== Reducing methane emissions ===
Rice is used as a model organism for investigating the molecular mechanisms of meiosis and [[DNA repair]] in higher plants. Meiosis is a key stage of the sexual cycle in which diploid cells in the [[ovule]] (female structure) and the [[Stamen|anther]] (male structure) produce haploid cells that develop further into gametophytes and [[Gamete#Plants|gametes]]. So far, 28 meiotic genes of rice have been characterized.<ref>{{cite journal | vauthors = Luo Q, Li Y, Shen Y, Cheng Z | title = Ten years of gene discovery for meiotic event control in rice | journal = Journal of Genetics and Genomics = Yi Chuan Xue Bao | volume = 41 | issue = 3 | pages = 125–137 | date = March 2014 | pmid = 24656233 | doi = 10.1016/j.jgg.2014.02.002 | doi-access = free }}</ref> Studies of rice gene OsRAD51C showed that this gene is necessary for [[Homologous recombination|homologous recombinational repair]] of DNA, particularly the accurate repair of DNA double-strand breaks during meiosis.<ref>{{cite journal | vauthors = Tang D, Miao C, Li Y, Wang H, Liu X, Yu H, Cheng Z | title = OsRAD51C is essential for double-strand break repair in rice meiosis | journal = Frontiers in Plant Science | volume = 5 | pages = 167 | year = 2014 | pmid = 24847337 | pmc = 4019848 | doi = 10.3389/fpls.2014.00167 | doi-access = free }}</ref> Rice gene OsDMC1 was found to be essential for pairing of homologous chromosomes during meiosis,<ref>{{cite journal | vauthors = Deng ZY, Wang T | title = OsDMC1 is required for homologous pairing in ''Oryza sativa'' | journal = [[Plant Molecular Biology]] | volume = 65 | issue = 1–2 | pages = 31–42 | date = September 2007 | pmid = 17562186 | doi = 10.1007/s11103-007-9195-2 | s2cid = 33673421 }}</ref> and rice gene OsMRE11 was found to be required for both synapsis of homologous chromosomes and repair of double-strand breaks during meiosis.<ref>{{cite journal | vauthors = Ji J, Tang D, Wang M, Li Y, Zhang L, Wang K, Li M, Cheng Z | display-authors = 6 | title = MRE11 is required for homologous synapsis and DSB processing in rice meiosis | journal = [[Chromosoma]] | volume = 122 | issue = 5 | pages = 363–376 | date = October 2013 | pmid = 23793712 | doi = 10.1007/s00412-013-0421-1 | s2cid = 17962445 }}</ref>


Producing rice in [[Paddy field|paddies]] is harmful for the environment due to the release of methane by [[Methanogen|methanogenic bacteria]]. These bacteria live in the anaerobic waterlogged soil, consuming nutrients released by rice roots. Putting the [[barley]] gene ''SUSIBA2'' into rice creates a shift in biomass production from root to shoot, decreasing the methanogen population, and resulting in a reduction of methane emissions of up to 97%. Further, the modification increases the amount of rice grains<!-- by 43%-->.<ref>{{cite journal |last1=Su |first1=J. |last2=Hu |first2=C. |last3=Yan |first3=X. |last4=Jin |first4=Y. |last5=Chen |first5=Z. |last6=Guan |first6=Q. |last7=Wang |first7=Y. |last8=Zhong |first8=D. |last9=Jansson |first9=C. |last10=Wang |first10=F. |last11=Schnürer |first11=A. |last12=Sun |first12=C. |display-authors=5 |title=Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice |journal=Nature |volume=523 |issue=7562 |pages=602–606 |date=July 2015 |pmid=26200336 |doi=10.1038/nature14673 |s2cid=4454200 |bibcode=2015Natur.523..602S }}</ref><ref>{{cite web |last=Gerry |first=C. |title=Feeding the World One Genetically Modified Tomato at a Time: A Scientific Perspective |url=http://sitn.hms.harvard.edu/flash/2015/feeding-the-world/ |publisher=[[Harvard University]] |access-date=September 11, 2015 |date=August 9, 2015 |archive-url=https://web.archive.org/web/20150910164510/http://sitn.hms.harvard.edu/flash/2015/feeding-the-world/ |archive-date=September 10, 2015 |url-status=live}}</ref>
{{ Anchor | Culture }}
==Cultural roles of rice==


=== Model organism ===
[[File:COLLECTIE TROPENMUSEUM Beeld van Dewi Sri de rijstgodin TMnr 60016918.jpg|thumb|right|Ancient statue of [[Dewi Sri]] from Java ({{Circa|9th century}})]]
Rice plays an important role in certain religions and popular beliefs. In many cultures relatives will scatter rice during or towards the end of a [[wedding]] ceremony in front of the bride and groom.<ref>[https://web.archive.org/web/20101127053611/http://ourweddingday.com/advice/Traditions/Origins-of-Wedding-Traditions/1058.aspx Origins of Wedding Traditions]. Ourweddingday.com (November 4, 2012). Retrieved on September 4, 2015.</ref>


Rice is used as a [[model organism]] for investigating the mechanisms of [[meiosis]] and [[DNA repair]] in higher plants.<ref>{{cite journal |last1=Luo |first1=Qiong |last2=Li |first2=Yafei |last3=Shen |first3=Yi |last4=Cheng |first4=Zhukuan |title=Ten years of gene discovery for meiotic event control in rice |journal=Journal of Genetics and Genomics |volume=41 |issue=3 |pages=125–137 |date=March 2014 |pmid=24656233 |doi=10.1016/j.jgg.2014.02.002 |doi-access=free }}</ref> For example, study using rice has shown that the gene ''OsRAD51C'' is necessary for the accurate repair of DNA double-strand breaks during meiosis.<ref>{{cite journal |last1=Tang |first1=Ding |last2=Miao |first2=Chunbo |last3=Li |first3=Yafei |last4=Wang |first4=Hongjun |last5=Liu |first5=Xiaofei |last6=Yu |first6=Hengxiu |last7=Cheng |first7=Zhukuan |title=OsRAD51C is essential for double-strand break repair in rice meiosis |journal=Frontiers in Plant Science |volume=5 |page=167 |year=2014 |pmid=24847337 |pmc=4019848 |doi=10.3389/fpls.2014.00167 |doi-access=free }}</ref>
The [[pounded rice ritual]] is conducted during weddings in [[Nepal]]. The bride gives a leafplate full of pounded rice to the groom after he requests it politely from her.<ref>Laura M. Ahearn (2011), ''Living Language: An Introduction to Linguistic Anthropology,'' p. 3</ref>


{{Anchor|Culture}}
In the [[Philippines]] rice wine, popularly known as ''[[tapuy]]'', is used for important occasions such as weddings, rice harvesting ceremonies and other celebrations.<ref>''Tapuy Cookbook & Cocktails,'' Philippine Rice Research Institute (2011)</ref>


== In human culture ==
[[Dewi Sri]] is the traditional rice goddess of the [[Javanese people|Javanese]], [[Sundanese people|Sundanese]], and [[Balinese people]] in [[Indonesia]]. Most rituals involving Dewi Sri are associated with the mythical origin attributed to the rice plant, the staple food of the region.<ref>{{cite web |url=http://www.sunda.org/sundanese/myths.htm |title=Early Mythology – Dewi Sri |publisher=Sunda.org |access-date=August 26, 2012 |archive-url=https://web.archive.org/web/20120905215151/http://www.sunda.org/sundanese/myths.htm |archive-date=September 5, 2012 |url-status=live}}</ref><ref>{{cite web |url=http://my.opera.com/mrtaufik/blog/2008/03/01/mitos-nyi-pohaci-sanghyang-asri-dewi-sri |title=(Indonesian) Mitos Nyi Pohaci/Sanghyang Asri/Dewi Sri |publisher=My.opera.com |date=March 1, 2008 |access-date=August 26, 2012 |archive-url=https://web.archive.org/web/20140223152906/http://my.opera.com/mrtaufik/blog/2008/03/01/mitos-nyi-pohaci-sanghyang-asri-dewi-sri |archive-date=February 23, 2014 |url-status=live}}</ref> In [[Thailand]], a similar rice deity is known as ''[[Phosop]]''; she is a deity more related to ancient local folklore than a goddess of a structured, mainstream religion.<ref>{{cite report |url=https://www.academia.edu/6002651|title=On the Role of Food Habits in the Context of the Identity and Cultural Heritage of South and South East Asia | work = Paper presented at the Cultural Heritage and Identity International Symposium 2013 | location = Sichuan University, Chengdu, China |access-date=October 6, 2014| vauthors = Romero-Frias X }}</ref> The same female rice deity is known as ''Po Ino Nogar'' in [[Cambodia]] and as ''Nang Khosop'' in [[Laos]]. Ritual offerings are made during the different stages of rice production to propitiate the Rice Goddess in the corresponding cultures.


[[File:COLLECTIE TROPENMUSEUM Beeld van Dewi Sri de rijstgodin TMnr 60016918.jpg|thumb|upright|Ancient statue of the rice goddess [[Dewi Sri]] from Java ({{Circa|9th century}}) ]]
A 2014 study of [[Han Chinese]] communities found that a history of farming rice makes cultures more psychologically interdependent, whereas a history of farming wheat makes cultures more independent.<ref>{{cite journal | vauthors = Talhelm T, Zhang X, Oishi S, Shimin C, Duan D, Lan X, Kitayama S | title = Large-scale psychological differences within China explained by rice versus wheat agriculture | journal = Science | volume = 344 | issue = 6184 | pages = 603–608 | date = May 2014 | pmid = 24812395 | doi = 10.1126/science.1246850 | s2cid = 206552838 | bibcode = 2014Sci...344..603T }}</ref>


Rice plays an important role in certain religions and popular beliefs. In Hindu wedding ceremonies, rice, denoting fertility, prosperity, and purity, is thrown into the sacred fire, a custom modified in Western weddings, where people throw rice.<ref>{{cite journal |last1=Ahuja |first1=Subhash C. |last2=Ahuja |first2=Uma |title=Rice in religion and tradition |journal=2nd International Rice Congress, October 9–13, 2006 |year=2006 |url=https://www.researchgate.net/publication/321334487 |location=New Delhi |pages=45–52 }}</ref> In Malay weddings, rice features in multiple special wedding foods such as sweet glutinous rice.<ref name="Muhammad Zahari Ramly Ahmad 2013">{{cite journal |last1=Muhammad |first1=Rosmaliza |last2=Zahari |first2=Mohd Salehuddin Mohd |last3=Ramly |first3=Alina Shuhaida Muhammad |last4=Ahmad |first4=Roslina |title=The Roles and Symbolism of Foods in Malay Wedding Ceremony |journal=Procedia - Social and Behavioral Sciences |volume=101 |year=2013 |doi=10.1016/j.sbspro.2013.07.200 |pages=268–276 |doi-access=free }}</ref> In Japan and the Philippines, rice wine is used for weddings and other celebrations.<ref>{{cite journal |last1=Ahuja |first1=Uma |last2=Thakrar |first2=Rashmi |last3=Ahuja |first3=S. C. |year=2001 |title=Alcoholic rice beverages |journal=Asian Agri-History |volume=5 |issue=4 |pages=309–319 |url=https://www.researchgate.net/publication/301948904}}</ref> [[Dewi Sri]] is a goddess of the Indo-Malaysian archipelago, who in myth is transformed into rice or other crops.<ref name="Wessing 1990">{{cite journal |last=Wessing |first=Robert |title=Sri and Sedana and Sita and Rama: Myths of Fertility and Generation |journal=[[Asian Folklore Studies]] |volume=49 |issue=2 |date=1990 |pages=235–257 |doi=10.2307/1178035 |jstor=1178035 }}</ref> The start of the rice planting season is marked in Asian countries including Nepal and Cambodia with a [[Royal Ploughing Ceremony]].<ref name="Xinhua-Camb-plough-2017">{{cite news |title=Cambodia marks beginning of farming season with royal ploughing ceremony |work=Xinhua |date=March 21, 2017 |url=http://www.xinhuanet.com/english/2018-05/03/c_137153698.htm |archive-url=https://web.archive.org/web/20180503130501/http://www.xinhuanet.com/english/2018-05/03/c_137153698.htm |url-status=dead |archive-date=May 3, 2018 |language=en |access-date=December 6, 2021}}</ref><ref name="Khmer-Times">{{cite web |title=Ceremony Predicts Good Year |website=[[Khmer Times]] |date=May 23, 2016 |url=http://www.khmertimeskh.com/24156/ceremony-predicts-good-year/ |access-date=December 6, 2021}}</ref><ref name="Sen-2019">{{cite web |last=Sen |first=S. |title=Ancient royal paddy planting ceremony marked |website=The Himalayan Times |date=July 2, 2019 |url=http://thehimalayantimes.com/nepal/ancient-royal-paddy-planting-ceremony-marked |access-date=December 6, 2021}}</ref>
A [[Royal Ploughing Ceremony]] is held in certain Asian countries to mark the beginning of the rice planting season. It is still honored in the kingdoms of [[Cambodia]]<ref name="Xinhua-Camb-plough-2017">{{cite web | title=Cambodia marks beginning of farming season with royal ploughing ceremony | website=[[Xinhua]] | date=March 21, 2017 | url=http://www.xinhuanet.com/english/2018-05/03/c_137153698.htm | archive-url=https://web.archive.org/web/20180503130501/http://www.xinhuanet.com/english/2018-05/03/c_137153698.htm | url-status=dead | archive-date=May 3, 2018 | language=en | access-date=December 6, 2021}}</ref><ref name="Khmer-Times">{{cite web | title=Ceremony Predicts Good Year | website=[[Khmer Times]] | date=May 23, 2016 | url=http://www.khmertimeskh.com/24156/ceremony-predicts-good-year/ | access-date=December 6, 2021}}</ref> and [[Thailand]].<ref name="Star-Thai-coron-plough">{{cite video | url=http://www.youtube.com/watch?v=frqy_MClMDY | title=New Thai king and queen take part in 'Royal Ploughing' ceremony | date=May 9, 2019 | website=[[YouTube]] | author= [[The Star (Malaysia)|The Star]]}}</ref><ref name="Thai-plough-cancel-2021">{{cite web | title=Thailand king cancels ceremonies as COVID surges | website=[[The Nikkei|Nikkei Asia]] | date=May 4, 2021 | url=http://asia.nikkei.com/Politics/Turbulent-Thailand/Thailand-king-cancels-ceremonies-as-COVID-surges | access-date=December 6, 2021}}</ref> The 2,600-year-old tradition {{endash}} begun by [[Śuddhodana]] in [[Kapilavastu (ancient city)|Kapilavastu]] {{endash}} was revived in the republic of [[Nepal]] in 2017 after a lapse of a few years.<ref name="Sen-2019">{{cite web | vauthors = Sen S | title=Ancient royal paddy planting ceremony marked | website=[[The Himalayan Times]] | date=July 2, 2019 | url=http://thehimalayantimes.com/nepal/ancient-royal-paddy-planting-ceremony-marked | access-date=December 6, 2021 | location=[[Bhairahawa]]}}</ref>

Thai king [[Vajiralongkorn]] released five particular rice varieties to celebrate [[Coronation of Vajiralongkorn|his coronation]].<ref name="Vajiralongkorn-coron" />


== See also ==
== See also ==

{{Portal|Food|Agriculture|Plants}}
<!-- Please keep entries in alphabetical order & add a short description [[WP:SEEALSO]] -->
<!-- Please keep entries in alphabetical order -->
<!--ABC-->
{{div col|colwidth=15em|small=yes}}
* [[Artificial rice]]
* [[Artificial rice]]
<!--DEF-->
* [[Glutinous rice]]
* [[List of dried foods]]
* [[Direct seeded rice]]
<!--GHIJ-->
* [[List of rice cultivars]]
<!--KLM-->
* [[List of rice dishes]]
* [[List of rice dishes]]
<!--NOP-->
* [[Maratelli]] rice
<!--QRS-->
* [[Fungiculture#Substrates|Mushroom production on rice straw]]
* [[Leaf Color Chart]]
* [[Post-harvest losses (grains)|Post-harvest losses]]
* [[Puffed rice]]
* [[Rice Belt]]
* [[Rice Belt]]
<!--TUVW-->
* [[Rice bran oil]]
<!--XYZ-->
* [[Rice bread]]
<!-- alphabetical order! -->{{-}}<!--needed to avoid having images running into reflist-->
* [[Rice wine]]
* [[Rice writing]]
* [[Rijsttafel]]
* [[Risotto]]
* [[Straw]]
* [[System of Rice Intensification]]
* [[Texas rice production]]
* [[Upland rice]]
* [[Wild rice]]
* [[Direct seeded rice]]{{div col end}}
<!-- please keep entries in alphabetical order -->


== References ==
== References ==

{{Reflist|refs=
{{reflist}}
<ref name="LSU-AgCenter-varieties-2021">{{cite web|title=Rice Varieties & Management Tips|website=[[Louisiana State University Agricultural Center]]|archive-date=November 25, 2020|url=http://www.lsuagcenter.com/articles/page1576103197216|date=November 24, 2020|archive-url=https://web.archive.org/web/20201125202409/https://www.lsuagcenter.com/~/media/system/8/1/e/1/81e17e54a628e198b585df0213ccfb7d/p2270_2021ricevarietiesmgmttipsrev_rh1120dharrellpdf.pdf}}</ref>
}}
*{{cite journal | last1=Liu | first1=Wende | last2=Liu | first2=Jinling | last3=Triplett | first3=Lindsay | last4=Leach | first4=Jan E. | last5=Wang | first5=Guo-Liang | title=Novel Insights into Rice Innate Immunity Against Bacterial and Fungal Pathogens | journal=[[Annual Review of Phytopathology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=52 | issue=1 | date=August 4, 2014 | issn=0066-4286 | doi=10.1146/annurev-phyto-102313-045926 | pages=213–241 | pmid=24906128 | s2cid=9244874}}
{{reflist|group="Liu"}}


== Further reading ==
== Further reading ==

* {{cite journal |last1=Liu |first1=Wende |last2=Liu |first2=Jinling |last3=Triplett |first3=Lindsay |last4=Leach |first4=Jan E. |last5=Wang |first5=Guo-Liang |title=Novel insights into rice innate immunity against bacterial and fungal pathogens |journal=[[Annual Review of Phytopathology]] |volume=52 |issue=1 |pages=213–241 |date=August 4, 2014 |pmid=24906128 |doi=10.1146/annurev-phyto-102313-045926 |publisher=[[Annual Reviews (publisher)|Annual Reviews]] |s2cid=9244874 |ref=none}}
[[File:Hainanese chicken rice in Singapore.jpg|thumb|right|[[Hainanese]] chicken rice in Singapore]]
* {{cite journal |last=Deb |first=D. |title=Restoring Rice Biodiversity |journal=[[Scientific American]] |volume=321 |issue=4 |date=October 2019 |pages=54–61 |doi=10.1038/scientificamerican1019-54 |pmid=39010400 |quote=India originally possessed some 110,000 [[landrace]]s of rice with diverse and valuable properties. These include enrichment in vital nutrients and the ability to withstand flood, drought, salinity or pest infestations. The [[Green Revolution]] covered fields with a few high-yielding varieties, so that roughly 90 percent of the landraces vanished from farmers' collections. High-yielding varieties require expensive inputs. They perform abysmally on marginal farms or in adverse environmental conditions, forcing poor farmers into debt. |ref=none}}
{{refbegin}}
* {{cite book |last=Singh |first=B. N. |date=2018 |title=Global Rice Cultivation & Cultivars |url=http://www.studiumpress.in/global-rice-cultivation-cultivars.html |location=New Delhi |publisher=Studium Press |isbn= 978-1-62699-107-1 |access-date=March 14, 2018 |archive-url=https://web.archive.org/web/20180314175208/http://www.studiumpress.in/global-rice-cultivation-cultivars.html |archive-date=March 14, 2018 |url-status=dead |ref=none}}
* {{cite journal | vauthors = Liu W, Liu J, Triplett L, Leach JE, Wang GL | title = Novel insights into rice innate immunity against bacterial and fungal pathogens | journal = [[Annual Review of Phytopathology]] | volume = 52 | issue = 1 | pages = 213–241 | date = August 4, 2014 | pmid = 24906128 | doi = 10.1146/annurev-phyto-102313-045926 | publisher = [[Annual Reviews (publisher)|Annual Reviews]] | s2cid = 9244874 }}
* {{cite journal | vauthors = Deb D | title = Restoring Rice Biodiversity | journal = [[Scientific American]] | volume = 321 | issue = 4 | date = October 2019 | pages = 54–61 | quote = India originally possessed some 110,000 [[landrace]]s of rice with diverse and valuable properties. These include enrichment in vital nutrients and the ability to withstand flood, drought, salinity or pest infestations. The [[Green Revolution]] covered fields with a few high-yielding varieties, so that roughly 90 percent of the landraces vanished from farmers' collections. High-yielding varieties require expensive inputs. They perform abysmally on marginal farms or in adverse environmental conditions, forcing poor farmers into debt. }}
* {{cite book| vauthors = Singh BN |date= 2018|title= Global Rice Cultivation & Cultivars|url= http://www.studiumpress.in/global-rice-cultivation-cultivars.html|location= New Delhi|publisher= [[Studium Press LLC]] |isbn= 978-1-62699-107-1|access-date= March 14, 2018|archive-url= https://web.archive.org/web/20180314175208/http://www.studiumpress.in/global-rice-cultivation-cultivars.html|archive-date= March 14, 2018|url-status= dead}}
{{refend}}

== External links ==
* [http://irri.org/ International Rice Research Institute] (IRRI)


{{Varieties of rice}}
{{Varieties of rice}}
{{Rice production}}
{{Rice production}}
{{Cereals}}
{{Cereals}}
{{Agriculture country lists}}
{{Rice dishes}}
{{Rice dishes}}
{{Cuisine}}

{{Authority control}}
{{Authority control}}


[[Category:Rice|Rice]]












[[Category:Rice| ]]
[[Category:Crops originating from China]]
[[Category:Crops originating from China]]
[[Category:Grasses of Asia]]
[[Category:Grasses of Asia]]

Latest revision as of 15:57, 21 November 2024

Rice plant (Oryza sativa) with branched panicles containing many grains on each stem
Rice grains of different varieties at the International Rice Research Institute

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 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 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 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 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 a role in various religions and traditions, such as in weddings.

Description

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.[1] The self-fertile flowers are produced in a panicle, 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.[2]

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 the year provided that sufficient water is made available.[3] It is normally an annual, but in the tropics it can survive as a perennial, producing a ratoon crop.[4]

Agronomy

Growing

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.[5]

Rice grains can be planted directly into 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.[6] 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 the machine.[7] Rice does not thrive if continuously submerged.[8] 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 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.[9] Deepwater rice varieties tolerate flooding to a depth of over 50 centimetres for at least a month.[10] Upland rice is grown without flooding, in hilly or mountainous regions; it is rainfed like wheat or maize.[11]

Ploughing a rice terrace with water buffaloes in Java
Farmers planting rice by hand in Cambodia
Mechanised rice planting in Japan
Ancient mountainside rice terraces at Banaue, Philippines

Harvesting

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.[12] The grain is ready to harvest when the moisture content is 20–25%. Harvesting involves reaping, stacking the cut stalks, threshing to separate the grain, and cleaning by winnowing or screening.[13] 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.[14]

After the harvest, rice straw is gathered in the traditional way from small paddy fields in Mae Wang, Thailand
Burning of rice residues to prepare the land for wheat planting in Sangrur, India
Drying rice in Peravoor, India

Evolution

Phylogeny

The edible rice species are members of the BOP clade within the grass family, the Poaceae. The rice subfamily, Oryzoideae, 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.[15]

Poaceae

other grasses

PACMAD clade

(inc. the C4 grasses, maize, sorghum)

BOP clade
Oryzoideae

Streptogyneae

Ehrharteae

Phyllorachideae

Oryzeae

Wild rices inc. Zizania

Oryza

other rice species and subspecies

O. sativa (Asian rice)

O. glaberrima (African rice)

Bambusoideae (bamboos)

Pooideae (grasses and cereals inc. wheat, barley)

History

Bas-relief of 9th century Borobudur in Indonesia describes rice barns and rice plants infested by mice.

Oryza sativa rice was first domesticated in China 9,000 years ago,[16] by people of Neolithic cultures in the Upper and Lower Yangtze, associated with Hmong-Mien-speakers and pre-Austronesians, respectively.[17][18][19][20] 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 a single domestication event for O. sativa.[21] Both indica and japonica forms of Asian rice sprang from a single domestication event in China from the wild rice Oryza rufipogon.[22][21] 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.[23]

Rice was introduced early into Sino-Tibetan cultures in northern China by around 6000 to 5600 years ago,[24][25][18] and to the Korean peninsula and Japan by around 5500 to 3200 years ago.[26][27] 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 the voyage to the rest of the Pacific.[17][28][29] It reached Austroasiatic and Kra-Dai-speakers in Mainland Southeast Asia and southern China by 5000 years ago.[17][30]

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.[31] The now less common Oryza glaberrima (African rice) was independently domesticated in Africa around 3,000 years ago,[31] and introduced to the Americas by the Spanish.[32] 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.[33]

Commerce

Rice production – 2021
Country Millions of tonnes
 China 213
 India 195
 Bangladesh 57
 Indonesia 54
 Vietnam 44
 Thailand 30
World 787[34]

Production

In 2021, world production of rice was 787 million tonnes, led by China and India with a combined 52% of the total.[34] This placed rice fourth in the list of crops by production, after sugarcane, maize, and wheat.[35] Other major producers were Bangladesh, Indonesia and Vietnam.[35] 90% of world production is from Asia.[36]

Yield records

The average world yield for rice was 4.7 metric tons per hectare (2.1 short tons per acre), in 2022.[37] 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.[38]

Food security

Rice is a major food staple in Asia, Latin America, and some parts of Africa,[39] feeding over half the world's population.[36] 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 was stored by rural households.[40]

Processing

Five-step animation showing the removal of successive layers from raw rice grains, starting with the grain with its inedible hull and ending with polished white rice.
Rice processing removes one or more layers to create marketable products.
  1. Rice with chaff
  2. Brown rice
  3. Rice with germ
  4. White rice with bran residue
  5. Polished
  1. Chaff
  2. Bran
  3. Bran residue
  4. Cereal germ
  5. Endosperm

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.[41] Brown rice only has the inedible husk removed.[42] Further milling removes bran and the germ to create successively whiter products.[42] Parboiled rice 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.[42] Rice does not contain gluten, so is suitable for people on a gluten-free diet.[43] 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 the essential amino acids in sufficient amounts for good health.[44]

Trade

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.[45] Developing countries are the main players in the world rice trade; by 2012, India was the largest exporter of rice, with Thailand and Vietnam the other largest exporters.[46]

Worldwide consumption

As of 2016, the countries that consumed the most rice were China (29% of total), India, and Indonesia.[47] 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 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.[48]

Food

Cooked white rice, medium-grain, unenriched
Nutritional value per 100 g (3.5 oz)
Energy544 kJ (130 kcal)
28.6 g
0.2 g
2.4 g
Vitamins and minerals
VitaminsQuantity
%DV
Thiamine (B1)
2%
0.02 mg
Riboflavin (B2)
2%
0.02 mg
Niacin (B3)
3%
0.4 mg
Pantothenic acid (B5)
8%
0.41 mg
Vitamin B6
3%
0.05 mg
Folate (B9)
1%
2 μg
MineralsQuantity
%DV
Calcium
0%
3 mg
Iron
1%
0.2 mg
Magnesium
3%
13 mg
Manganese
17%
0.38 mg
Phosphorus
3%
37 mg
Potassium
1%
29 mg
Sodium
0%
0 mg
Zinc
4%
0.4 mg
Other constituentsQuantity
Water69 g

Percentages estimated using US recommendations for adults,[49] except for potassium, which is estimated based on expert recommendation from the National Academies.[50]

Eating qualities

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 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.[51]

Nutrition

Cooked white rice 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).[52] In 2018, the World Health Organization strongly recommended fortifying rice with iron, and conditionally recommended fortifying it with vitamin A and with folic acid.[53]

Golden rice

Golden rice 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.[54][55] Golden rice has been opposed by activists, such as in the Philippines.[56] In 2016 more than 100 Nobel laureates encouraged the use of genetically modified organisms, such as golden rice, for the benefits these could bring.[57]

Rice and climate change

Greenhouse gases from rice production

Scientists measuring the greenhouse gas emissions of rice

In 2022, greenhouse gas emissions from rice cultivation were estimated at 5.7 billion tonnes CO2eq, representing 1.2% of total emissions.[58] Within the agriculture sector, rice produces almost half the greenhouse gas emissions from croplands,[59] some 30% of agricultural methane emissions, and 11% of agricultural nitrous oxide emissions.[60] Methane is released from rice fields subject to long-term flooding, as this inhibits the soil from absorbing atmospheric oxygen, resulting in anaerobic fermentation of organic matter in the soil.[61] Emissions can be limited by planting new varieties, not flooding continuously, and removing straw.[62]

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.[63]

Effects of climate change on rice production

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[64] while another study predicts global rice cultivation will increase initially, plateauing at about 3°C warming (2091–2100 relative to 1850–1900).[65]

The impacts of climate change on rice cultivation vary across geographic location and socioeconomic context. For example, rising temperatures and decreasing solar radiation during 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.[66][67] 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 the crop would be lost under these conditions.[68][69]

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.[70]

Pests, weeds, and diseases

Pests and weeds

Chinese rice grasshopper (Oxya chinensis)

Rice yield can be reduced by weed growth, and a wide variety of pests including insects, nematodes, rodents such as rats, snails, and birds.[71] Major rice insect pests include armyworms, rice bugs, black bugs, cutworms, field crickets, grasshoppers, leafhoppers, mealybugs, and planthoppers.[72] High rates of nitrogen fertiliser application may worsen aphid outbreaks.[73] Weather conditions can contribute to pest outbreaks: rice gall midge outbreaks are worsened by high rainfall in the wet season, while thrips outbreaks are associated with drought.[74]

Diseases

Healthy rice (left) and rice with rice blast

Rice blast, caused by the fungus Magnaporthe grisea, is the most serious disease of growing rice.[75] 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.[76] Other major rice diseases include sheath blight (caused by Rhizoctonia solani), false smut (Ustilaginoidea virens), and bacterial panicle blight (Burkholderia glumae).[76] Viral diseases include rice bunchy stunt, rice dwarf, rice tungro, and rice yellow mottle.[77]

Pest management

Crop protection scientists are developing sustainable techniques for managing rice pests.[78] Sustainable pest management is based on four principles: biodiversity, host plant resistance, landscape ecology, and hierarchies in a landscape—from biological to social.[79] Farmers' pesticide applications are often unnecessary.[80] 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.[81] 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.[82]

A farmer grazes his ducks in paddy fields, Central Java

Farmers in China, Indonesia and 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.[83][84]

Rice plants produce their own chemical defences to protect themselves from pest attacks. Some synthetic chemicals, such as 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.[85] 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.[86]

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 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.[87]

Ecotypes and cultivars

Rice seed collection from IRRI

The International Rice Research Institute maintains the International Rice Genebank, which holds over 100,000 rice varieties.[88][89] Much of southeast Asia grows sticky or glutinous rice varieties.[90] High-yield cultivars of rice suitable for cultivation in Africa, called the New Rice for Africa (NERICA), have been developed to improve food security and alleviate poverty in Sub-Saharan Africa.[91]

The complete genome of rice was sequenced in 2005, making it the first crop plant to reach this status.[92] Since then, the genomes of hundreds of types of rice, both wild and cultivated, and including both Asian and African rice species, have been sequenced.[93]

Biotechnology

High-yielding varieties

The high-yielding varieties are a group of crops created during the Green Revolution to increase global food production radically. The first Green Revolution rice variety, IR8, was produced in 1966 at the International Rice Research Institute through a cross between an Indonesian variety named "Peta" and a Chinese variety named "Dee Geo Woo Gen".[94] Green Revolution varieties were bred to have short strong stems so that the rice would not lodge or fall over. This enabled them to stay upright and productive even with heavy applications of fertiliser.[94]

Expression of human proteins

Ventria Bioscience has genetically modified rice to express lactoferrin and lysozyme which are proteins usually found in breast milk, and human serum albumin. These proteins have antiviral, antibacterial, and antifungal effects.[95] Rice containing these added proteins can be used as a component in oral rehydration solutions to treat diarrheal diseases, thereby shortening their duration and reducing recurrence. Such supplements may also help reverse anemia.[96]

Flood-tolerance

International Rice Research Institute researchers checking deepwater rice in the Philippines

In areas subject to flooding, farmers have long planted flood tolerant varieties known as deepwater rice. In South and South East Asia, flooding affects some 20 million hectares (49 million acres) each year.[97] Flooding has historically led to massive losses in yields, such as in the Philippines, where in 2006, rice crops worth $65 million were lost to flooding.[98]

Standard rice varieties cannot withstand stagnant flooding for more than about a week, since it disallows the plant access to necessary requirements such as sunlight and gas exchange. The Swarna Sub1 cultivar can tolerate week-long submergence, consuming carbohydrates efficiently and continuing to grow.[97] So-called "scuba rice"[99] with the Sub1A transgene is robustly tolerant of submergence for as long as two weeks, offering much improved flood survival for farmers' crops. IRRI has created Sub1A varieties and distributed them to Bangladesh, India, Indonesia, Nepal, and the Philippines.[100]

Drought-tolerance

Drought represents a significant environmental stress for rice production, with 19–23 million hectares (47–57 million acres) of rainfed rice production in South and South East Asia often at risk.[101][102] Under drought conditions, without sufficient water to afford them the ability to obtain the required levels of nutrients from the soil, conventional commercial rice varieties can be severely affected—as happened for example in India early in the 21st century.[103]

The International Rice Research Institute conducts research into developing drought-tolerant rice varieties, including the varieties Sahbhagi Dhan, Sahod Ulan, and Sookha dhan, currently being employed by farmers in India, the Philippines, and Nepal respectively.[102] In addition, in 2013 the Japanese National Institute for Agrobiological Sciences led a team which successfully inserted the DEEPER ROOTING 1 (DRO1) gene, from the Philippine upland rice variety Kinandang Patong, into the popular commercial rice variety IR64, giving rise to a far deeper root system in the resulting plants.[103] This facilitates an improved ability for the rice plant to derive its required nutrients in times of drought via accessing deeper layers of soil, a feature demonstrated by trials which saw the IR64 + DRO1 rice yields drop by 10% under moderate drought conditions, compared to 60% for the unmodified IR64 variety.[103][104]

Salt-tolerance

Soil salinity poses a major threat to rice crop productivity, particularly along low-lying coastal areas during the dry season.[101][105] For example, roughly 1 million hectares (2.5 million acres) of the coastal areas of Bangladesh are affected by saline soils.[106] These high concentrations of salt can severely affect rice plants' physiology, especially during early stages of growth, and as such farmers are often forced to abandon these areas.[107]

Progress has been made in developing rice varieties capable of tolerating such conditions; the hybrid created from the cross between the commercial rice variety IR56 and the wild rice species Oryza coarctata is one example.[108] O. coarctata can grow in soils with double the limit of salinity of normal varieties, but does not produce edible rice.[108] Developed by the International Rice Research Institute, the hybrid variety utilises specialised leaf glands that remove salt into the atmosphere. It was produced from one successful embryo out of 34,000 crosses between the two species; this was then backcrossed to IR56 with the aim of preserving the genes responsible for salt tolerance that were inherited from O. coarctata.[107]

Cold tolerance

Rice is sensitive to temperatures below 12C. Sowing takes place once the daily average temperature is reliably above this limit. Average temperatures below that reduce growth; if sustained for over four days, germination and seedling growth are harmed and seedlings may die. In larger plants subjected to cold, rice blast is encouraged, seriously reducing yield. As of 2022, researchers continue to study the mechanisms of chilling tolerance in rice and its genetic basis.[109]

Reducing methane emissions

Producing rice in paddies is harmful for the environment due to the release of methane by methanogenic bacteria. These bacteria live in the anaerobic waterlogged soil, consuming nutrients released by rice roots. Putting the barley gene SUSIBA2 into rice creates a shift in biomass production from root to shoot, decreasing the methanogen population, and resulting in a reduction of methane emissions of up to 97%. Further, the modification increases the amount of rice grains.[110][111]

Model organism

Rice is used as a model organism for investigating the mechanisms of meiosis and DNA repair in higher plants.[112] For example, study using rice has shown that the gene OsRAD51C is necessary for the accurate repair of DNA double-strand breaks during meiosis.[113]

In human culture

Ancient statue of the rice goddess Dewi Sri from Java (c. 9th century)

Rice plays an important role in certain religions and popular beliefs. In Hindu wedding ceremonies, rice, denoting fertility, prosperity, and purity, is thrown into the sacred fire, a custom modified in Western weddings, where people throw rice.[114] In Malay weddings, rice features in multiple special wedding foods such as sweet glutinous rice.[115] In Japan and the Philippines, rice wine is used for weddings and other celebrations.[116] Dewi Sri is a goddess of the Indo-Malaysian archipelago, who in myth is transformed into rice or other crops.[117] The start of the rice planting season is marked in Asian countries including Nepal and Cambodia with a Royal Ploughing Ceremony.[118][119][120]

See also

References

  1. ^ "Oryza sativa L." Royal Botanic Gardens, Kew. Retrieved December 6, 2023.
  2. ^ "The Rice Plant". Rice Hub. Retrieved December 6, 2023.
  3. ^ Kawure, S.; Garba, A.A.; Fagam, A.S.; Shuaibu, Y.M.; Sabo, M.U.; Bala, R.A. (December 31, 2022). "Performance of Lowland Rice (Oryza sativa L.) as Influenced by Combine Effect of Season and Sowing Pattern in Zigau". Journal of Rice Research and Developments. 5 (2). doi:10.36959/973/440.
  4. ^ "The Rice Plant and How it Grows". International Rice Research Institute. Archived from the original on January 6, 2009.
  5. ^ Beighley, Donn H. (2010). "Growth and Production of Rice". In Verheye, Willy H. (ed.). Soils, Plant Growth and Crop Production Volume II. EOLSS Publishers. p. 49. ISBN 978-1-84826-368-0.
  6. ^ "How to plant rice". International Rice Research Institute. Retrieved December 29, 2023.
  7. ^ "Transplanting". International Rice Research Institute. Retrieved December 29, 2023.
  8. ^ Uphoff, Norman. "More rice with less water through SRI - the System of Rice Intensification" (PDF). Cornell University. Archived from the original (PDF) on December 26, 2011. Retrieved May 13, 2012.
  9. ^ "Water Management". International Rice Research Institute. Retrieved November 4, 2023.
  10. ^ Catling, David (1992). "Deepwater Rice Cultures in the Ganges-Brahmaputra Basin". Rice in Deep Water. International Rice Research Institute. p. 2. ISBN 978-971-22-0005-2.
  11. ^ Gupta, Phool Chand; O'Toole, J. C. O'Toole (1986). Upland Rice: A Global Perspective. International Rice Research Institute. ISBN 978-971-10-4172-4.
  12. ^ "Harvesting systems". International Rice Research Institute. Retrieved January 3, 2024.
  13. ^ "Harvesting". International Rice Research Institute. Retrieved December 6, 2023.
  14. ^ "Drying". International Rice Research Institute. Retrieved December 6, 2023.
  15. ^ Soreng, Robert J.; Peterson, Paul M.; Romaschenko, Konstantin; Davidse, Gerrit; Teisher, Jordan K.; Clark, Lynn G.; Barberá, Patricia; Gillespie, Lynn J.; Zuloaga, Fernando O. (2017). "A worldwide phylogenetic classification of the Poaceae (Gramineae) II: An update and a comparison of two 2015 classifications". Journal of Systematics and Evolution. 55 (4): 259–290. doi:10.1111/jse.12262. hdl:10261/240149.
  16. ^ Fornasiero, Alice; Wing, Rod A.; Ronald, Pamela (January 2022). "Rice domestication". Current Biology. 32 (1): R20–R24. Bibcode:2022CBio...32..R20F. doi:10.1016/j.cub.2021.11.025. PMID 35015986.
  17. ^ a b c Bellwood, Peter (December 2011). "The Checkered Prehistory of Rice Movement Southwards as a Domesticated Cereal—from the Yangzi to the Equator". Rice. 4 (3–4): 93–103. Bibcode:2011Rice....4...93B. doi:10.1007/s12284-011-9068-9.
  18. ^ a b He, Keyang; Lu, Houyuan; Zhang, Jianping; Wang, Can; Huan, Xiujia (December 2017). "Prehistoric evolution of the dualistic structure mixed rice and millet farming in China". The Holocene. 27 (12): 1885–1898. doi:10.1177/0959683617708455.
  19. ^ Hsieh, Jaw-shu; Hsing, Yue-ie Caroline; Hsu, Tze-fu; Li, Paul Jen-kuei; Li, Kuang-ti; Tsang, Cheng-hwa (December 24, 2011). "Studies on Ancient Rice—Where Botanists, Agronomists, Archeologists, Linguists, and Ethnologists Meet". Rice. 4 (3–4): 178–183. Bibcode:2011Rice....4..178H. doi:10.1007/s12284-011-9075-x.
  20. ^ Chi, Zhang; Hung, Hsiao-Chun (2008). "The Neolithic of Southern China—Origin, Development, and Dispersal". Asian Perspectives. 47 (2): 299–329. doi:10.1353/asi.0.0004. hdl:10125/17291. JSTOR 42928744. Gale A191316867 Project MUSE 257900.
  21. ^ a b Vaughan, Duncan A.; Lu, Bao-Rong; Tomooka, Norihiko (April 2008). "The evolving story of rice evolution". Plant Science. 174 (4): 394–408. doi:10.1016/j.plantsci.2008.01.016.
  22. ^ Molina, J.; Sikora, M.; Garud, N.; Flowers, J. M.; Rubinstein, S.; et al. (2011). "Molecular evidence for a single evolutionary origin of domesticated rice". Proceedings of the National Academy of Sciences. 108 (20): 8351–8356. Bibcode:2011PNAS..108.8351M. doi:10.1073/pnas.1104686108. PMC 3101000. PMID 21536870.
  23. ^ Choi, Jae; et al. (2017). "The Rice Paradox: Multiple Origins but Single Domestication in Asian Rice". Molecular Biology and Evolution. 34 (4): 969–979. doi:10.1093/molbev/msx049. PMC 5400379. PMID 28087768.
  24. ^ Zhang, Jianping; Lu, Houyuan; Gu, Wanfa; Wu, Naiqin; Zhou, Kunshu; et al. (December 17, 2012). "Early Mixed Farming of Millet and Rice 7800 Years Ago in the Middle Yellow River Region, China". PLOS ONE. 7 (12): e52146. Bibcode:2012PLoSO...752146Z. doi:10.1371/journal.pone.0052146. PMC 3524165. PMID 23284907.
  25. ^ Fuller, Dorian Q. (December 2011). "Pathways to Asian Civilizations: Tracing the Origins and Spread of Rice and Rice Cultures". Rice. 4 (3–4): 78–92. Bibcode:2011Rice....4...78F. doi:10.1007/s12284-011-9078-7.
  26. ^ Crawford; Shen (1998). "The Origins of rice agriculture: recent progress in East Asia". Antiquity. 72 (278): 858–866. doi:10.1017/S0003598X00087494. S2CID 162486123.
  27. ^ Crawford, G. W. & Lee, G.-A. (March 2003). "Agricultural Origins in the Korean Peninsula". Antiquity. 77 (295): 87–95. doi:10.1017/s0003598x00061378. S2CID 163060564.
  28. ^ Beaujard, Philippe (August 2011). "The first migrants to Madagascar and their introduction of plants: linguistic and ethnological evidence" (PDF). Azania: Archaeological Research in Africa. 46 (2): 169–189. doi:10.1080/0067270X.2011.580142.
  29. ^ Carson, Mike T. (2012). "An overview of latte period archaeology" (PDF). Micronesica. 42 (1/2): 1–79. Archived (PDF) from the original on April 12, 2019. Retrieved January 25, 2019.
  30. ^ Higham, Charles F. W.; Douka, Katerina; Higham, Thomas F. G.; Hart, John P. (September 18, 2015). "A New Chronology for the Bronze Age of Northeastern Thailand and Its Implications for Southeast Asian Prehistory". PLOS ONE. 10 (9): e0137542. Bibcode:2015PLoSO..1037542H. doi:10.1371/journal.pone.0137542. PMC 4575132. PMID 26384011.
  31. ^ a b Choi, Jae Young (March 7, 2019). "The complex geography of domestication of the African rice Oryza glaberrima". PLOS Genetics. 15 (3): e1007414. doi:10.1371/journal.pgen.1007414. PMC 6424484. PMID 30845217.
  32. ^ National Research Council (1996). "African Rice". Lost Crops of Africa: Volume I: Grains. Vol. 1. National Academies Press. doi:10.17226/2305. ISBN 978-0-309-04990-0. Archived from the original on January 22, 2009. Retrieved July 18, 2008.
  33. ^ Morgan, Kenneth (July 1995). "The Organization of the Colonial American Rice Trade". The William and Mary Quarterly. 52 (3): 433–452. doi:10.2307/2947294. JSTOR 2947294.
  34. ^ a b "Rice production in 2021; Crops/Regions/World list/Production Quantity/Year (from pick lists)". FAOSTAT, UN Food and Agriculture Organization, Corporate Statistical Database. 2023. Retrieved December 4, 2023.
  35. ^ a b c World Food and Agriculture – Statistical Yearbook 2021. United Nations Food and Agriculture Organization. 2021. doi:10.4060/cb4477en. ISBN 978-92-5-134332-6. S2CID 240163091. Retrieved December 10, 2021.
  36. ^ a b Fukagawa, Naomi K.; Ziska, Lewis H. (October 11, 2019). "Rice: Importance for Global Nutrition". Journal of Nutritional Science and Vitaminology. 65 (Supplement): S2–S3. doi:10.3177/jnsv.65.S2. PMID 31619630.
  37. ^ "FAOSTAT: Production-Crops, 2022 data". United Nations Food and Agriculture Organization. 2022. Archived from the original on June 19, 2012. Retrieved January 12, 2012.
  38. ^ Yuan, Longping (2010). "A Scientist's Perspective on Experience with SRI in China for Raising the Yields of Super Hybrid Rice" (PDF). Cornell University. Archived from the original (PDF) on November 20, 2011.
  39. ^ "Food Staple". National Geographic Education. Retrieved December 6, 2023.
  40. ^ Kumar, Deepak; Kalita, Prasanta (January 15, 2017). "Reducing Postharvest Losses during Storage of Grain Crops to Strengthen Food Security in Developing Countries". Foods. 6 (1): 8. doi:10.3390/foods6010008. PMC 5296677. PMID 28231087.
  41. ^ "Milling". International Rice Research Institute. Retrieved January 4, 2024.
  42. ^ a b c "Types of rice". Rice Association. Archived from the original on August 2, 2018. Retrieved August 2, 2018.
  43. ^ Penagini, Francesca; Dilillo, Dario; Meneghin, Fabio; Mameli, Chiara; Fabiano, Valentina; Zuccotti, Gian (November 18, 2013). "Gluten-Free Diet in Children: An Approach to a Nutritionally Adequate and Balanced Diet". Nutrients. 5 (11). MDPI AG: 4553–4565. doi:10.3390/nu5114553. PMC 3847748. PMID 24253052.
  44. ^ Wu, Jianguo G.; Shi, Chunhai; Zhang, Xiaoming (March 2002). "Estimating the amino acid composition in milled rice by near-infrared reflectance spectroscopy". Field Crops Research. 75 (1): 1–7. Bibcode:2002FCrRe..75....1W. doi:10.1016/s0378-4290(02)00006-0.
  45. ^ Cendrowski, Scott (July 25, 2013). "The Rice Rush". Fortune. Retrieved January 4, 2024.
  46. ^ Chilkoti, A. (October 30, 2012). "India and the Price of Rice". Financial Times. London. Archived from the original on January 20, 2013.
  47. ^ "Global rice consumption continues to grow". Grain Central. March 26, 2018. Retrieved December 5, 2023.
  48. ^ "Rice Sector at a Glance". Economic Research Service, US Department of Agriculture. September 27, 2023. Retrieved December 5, 2023.
  49. ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". FDA. Archived from the original on March 27, 2024. Retrieved March 28, 2024.
  50. ^ National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.). Dietary Reference Intakes for Sodium and Potassium. The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US). ISBN 978-0-309-48834-1. PMID 30844154. Archived from the original on May 9, 2024. Retrieved June 21, 2024.
  51. ^ "Types of rice". The Rice Association. Retrieved March 24, 2024.
  52. ^ "FoodData Central: Rice, white, medium-grain, cooked, unenriched". US Department of Agriculture. April 2018. Retrieved December 5, 2023.
  53. ^ L. M., De-Regil; J. P., Peña-Rosas; A., Laillou; R., Moench-Pfanner; L. A., Mejia; et al. (2018). Guideline: Fortification of Rice with Vitamins and Minerals as a Public Health Strategy. World Health Organization. ISBN 978-92-4-155029-1. PMID 30307723. Retrieved December 5, 2023.
  54. ^ "Golden Rice Q&A". Golden Rice Project. Retrieved January 3, 2024.
  55. ^ Ye, Xudong; Al-Babili, Salim; Klöti, Andreas; Zhang, Jing; Lucca, Paola; et al. (January 14, 2000). "Engineering the Provitamin A (β-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm". Science. 287 (5451): 303–305. Bibcode:2000Sci...287..303Y. doi:10.1126/science.287.5451.303. PMID 10634784. S2CID 40258379.
  56. ^ Lynas, Mark (August 26, 2013). "Anti-GMO Activists Lie About Attack on Rice Crop (and About So Many Other Things)". Slate Magazine. Retrieved August 21, 2021.
  57. ^ Roberts, Richard J. (2018). "The Nobel Laureates' Campaign Supporting GMOs". Journal of Innovation & Knowledge. 3 (2): 61–65. doi:10.1016/j.jik.2017.12.006.
  58. ^ "Sectors: Rice cultivation". climatetrace.org. Retrieved December 7, 2023.
  59. ^ Qian, Haoyu; Zhu, Xiangchen; Huang, Shan; Linquist, Bruce; Kuzyakov, Yakov; et al. (October 2023). "Greenhouse gas emissions and mitigation in rice agriculture". Nature Reviews Earth & Environment. 4 (10): 716–732. Bibcode:2023NRvEE...4..716Q. doi:10.1038/s43017-023-00482-1. hdl:20.500.12327/2431. S2CID 263197017. Rice paddies …. account for ~48% of greenhouse gas (GHG) emissions from croplands.
  60. ^ Gupta, Khushboo; Kumar, Raushan; Baruah, Kushal Kumar; Hazarika, Samarendra; Karmakar, Susmita; Bordoloi, Nirmali (June 2021). "Greenhouse gas emission from rice fields: a review from Indian context". Environmental Science and Pollution Research International. 28 (24): 30551–30572. Bibcode:2021ESPR...2830551G. doi:10.1007/s11356-021-13935-1. PMID 33905059. S2CID 233403787.
  61. ^ Neue, Heinz-Ulrich (1993). "Methane Emission from Rice Fields". BioScience. 43 (7): 466–474. doi:10.2307/1311906. JSTOR 1311906.
  62. ^ Qian, Haoyu; Zhu, Xiangchen; Huang, Shan; Linquist, Bruce; Kuzyakov, Yakov; et al. (October 2023). "Greenhouse gas emissions and mitigation in rice agriculture". Nature Reviews Earth & Environment. 4 (10): 716–732. Bibcode:2023NRvEE...4..716Q. doi:10.1038/s43017-023-00482-1. hdl:20.500.12327/2431. S2CID 263197017.
  63. ^ Searchinger, Tim; Adhya, Tapan K. (2014). "Wetting and Drying: Reducing Greenhouse Gas Emissions and Saving Water from Rice Production". World Resources Institute.
  64. ^ Zhao, Chuang; Liu, Bing; Piao, Shilong; Wang, Xuhui; Lobell, David B.; et al. (August 29, 2017). "Temperature increase reduces global yields of major crops in four independent estimates". Proceedings of the National Academy of Sciences. 114 (35): 9326–9331. Bibcode:2017PNAS..114.9326Z. doi:10.1073/pnas.1701762114. PMC 5584412. PMID 28811375.
  65. ^ Iizumi, Toshichika; Furuya, Jun; Shen, Zhihong; Kim, Wonsik; Okada, Masashi; et al. (August 10, 2017). "Responses of crop yield growth to global temperature and socioeconomic changes". Scientific Reports. 7 (1): 7800. Bibcode:2017NatSR...7.7800I. doi:10.1038/s41598-017-08214-4. PMC 5552729. PMID 28798370.
  66. ^ Welch, Jarrod R.; Vincent, Jeffrey R.; Auffhammer, Maximilian; Moya, Piedad F.; Dobermann, Achim; Dawe, David (August 9, 2010). "Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures". Proceedings of the National Academy of Sciences. 107 (33): 14562–14567. doi:10.1073/pnas.1001222107. PMC 2930450. PMID 20696908.
  67. ^ Black, R. (August 9, 2010). "Rice yields falling under global warming". BBC News: Science & Environment. Archived from the original on April 5, 2018. Retrieved August 9, 2010.
  68. ^ Singh, S.K. (2016). "Climate Change: Impact on Indian Agriculture & its Mitigation". Journal of Basic and Applied Engineering Research. 3 (10): 857–859.
  69. ^ Rao, Prakash; Patil, Y. (2017). Reconsidering the Impact of Climate Change on Global Water Supply, Use, and Management. IGI Global. p. 330. ISBN 978-1-5225-1047-5.
  70. ^ Spaggiari, Ottavia (February 29, 2024). "Risotto crisis: the fight to save Italy's beloved dish from extinction". The Guardian.
  71. ^ "Pests and diseases management". International Rice Research Institute. Retrieved January 4, 2024.
  72. ^ "Insects". International Rice Research Institute. Retrieved January 4, 2024.
  73. ^ Jahn, Gary C.; Almazan, Liberty P.; Pacia, Jocelyn B. (2005). "Effect of Nitrogen Fertilizer on the Intrinsic Rate of Increase of Hysteroneura setariae (Thomas) (Homoptera: Aphididae) on Rice (Oryza sativa L.)". Environmental Entomology. 34 (4): 938. doi:10.1603/0046-225X-34.4.938. S2CID 1941852.
  74. ^ Douangboupha, B.; Khamphoukeo, K.; Inthavong, S.; Schiller, J.M.; Jahn, G.C. (2006). "Chapter 17: Pests and diseases of the rice production systems of Laos" (PDF). In Schiller, J.M.; Chanphengxay, M.B.; Linquist, B.; Rao, S.A. (eds.). Rice in Laos. Los Baños, Philippines: International Rice Research Institute. pp. 265–281. ISBN 978-971-22-0211-7. Archived from the original (PDF) on April 3, 2012.
  75. ^ Dean, Ralph A.; Talbot, Nicholas J.; Ebbole, Daniel J.; et al. (April 2005). "The genome sequence of the rice blast fungus Magnaporthe grisea". Nature. 434 (7036): 980–986. Bibcode:2005Natur.434..980D. doi:10.1038/nature03449. PMID 15846337.
  76. ^ a b Liu, Wende; Liu, Jinling; Triplett, Lindsay; Leach, Jan E.; Wang, Guo-Liang (August 4, 2014). "Novel Insights into Rice Innate Immunity Against Bacterial and Fungal Pathogens". Annual Review of Phytopathology. 52 (1): 213–241. doi:10.1146/annurev-phyto-102313-045926. PMID 24906128.
  77. ^ Hibino, H. (1996). "Biology and epidemiology of rice viruses". Annual Review of Phytopathology. 34 (1). Annual Reviews: 249–274. doi:10.1146/annurev.phyto.34.1.249. PMID 15012543.
  78. ^ Jahn, Gary C.; Khiev, B.; Pol, C.; Chhorn, N.; Pheng, S.; Preap, V. (2001). "Developing sustainable pest management for rice in Cambodia". In Suthipradit, S.; Kuntha, C.; Lorlowhakarn, S.; Rakngan, J. (eds.). Sustainable Agriculture: Possibility and Direction. Bangkok (Thailand): National Science and Technology Development Agency. pp. 243–258.
  79. ^ Savary, S.; Horgan, F.; Willocquet, L.; Heong (2012). "A review of principles for sustainable pest management in rice". Crop Protection. 32: 54. Bibcode:2012CrPro..32...54S. doi:10.1016/j.cropro.2011.10.012.
  80. ^ "Bangladeshi farmers banish insecticides". SCIDEV.net. July 30, 2004. Archived from the original on January 26, 2008. Retrieved May 13, 2012.
  81. ^ Wu, Jincai; Ge, Linquan; Liu, Fang; Song, Qisheng; Stanley, David (January 7, 2020). "Pesticide-Induced Planthopper Population Resurgence in Rice Cropping Systems". Annual Review of Entomology. 65 (1): 409–429. doi:10.1146/annurev-ento-011019-025215. PMID 31610135. S2CID 204702698.
  82. ^ Hamilton, Henry Sackville (January 18, 2008). "The pesticide paradox". International Rice Research Institute. Archived from the original on January 19, 2012.
  83. ^ Bezemer, Marjolein (October 23, 2022). "Mixed farming increases rice yield". reNature Foundation. Archived from the original on October 11, 2019. Retrieved January 2, 2024.
  84. ^ Cagauan, A. G.; Branckaert, R. D.; Van Hove, C. (2000). "Integrating fish and azolla into rice-duck farming in Asia" (PDF). Naga (ICLARM Quarterly). 23 (1): 4–10.
  85. ^ Xin, Zhaojun; Yu, Zhaonan; Erb, Matthias; Turlings, Ted C. J.; Wang, Baohui; et al. (April 2012). "The broad-leaf herbicide 2,4-dichlorophenoxyacetic acid turns rice into a living trap for a major insect pest and a parasitic wasp". The New Phytologist. 194 (2): 498–510. doi:10.1111/j.1469-8137.2012.04057.x. PMID 22313362.
  86. ^ Cheng, Yao; Shi, Zhao-Peng; Jiang, Li-Ben; Ge, Lin-Quan; Wu, Jin-Cai; Jahn, Gary C. (March 2012). "Possible connection between imidacloprid-induced changes in rice gene transcription profiles and susceptibility to the brown plant hopper Nilaparvatalugens Stål (Hemiptera: Delphacidae)". Pesticide Biochemistry and Physiology. 102 (3): 213–219. Bibcode:2012PBioP.102..213C. doi:10.1016/j.pestbp.2012.01.003. PMC 3334832. PMID 22544984.
  87. ^ Makkar, Gurpreet Singh; Bhatia, Dharminder; Suri, K.S.; Kaur, Simranjeet (2019). "Insect resistance in Rice (Oryza sativa L.): overview on current breeding interventions". International Journal of Tropical Insect Science. 39 (4): 259–272. doi:10.1007/s42690-019-00038-1. S2CID 202011174.
  88. ^ "The International Rice Genebank – conserving rice". International Rice Research Institute. Archived from the original on October 23, 2012.
  89. ^ Jackson, M. T. (September 1997). "Conservation of rice genetic resources: the role of the International Rice Genebank at IRRI". Plant Molecular Biology. 35 (1–2): 61–67. doi:10.1023/A:1005709332130. PMID 9291960. S2CID 3360337.
  90. ^ Sattaka, Patcha (December 27, 2016). "Geographical Distribution of Glutinous Rice in the Greater Mekong Sub-region". Journal of Mekong Societies. 12 (3): 27–48.
  91. ^ "NERICA: Rice for Life" (PDF). Africa Rice Center (WARDA). 2001. Archived from the original (PDF) on December 4, 2003. Retrieved July 7, 2008.
  92. ^ Gillis, J. (August 11, 2005). "Rice Genome Fully Mapped". The Washington Post. Archived from the original on March 30, 2017. Retrieved September 10, 2017.
  93. ^ Shang, Lianguang; Li, Xiaoxia; He, Huiying; Yuan, Qiaoling; Song, Yanni; et al. (2022). "A super pan-genomic landscape of rice". Cell Research. 32 (10): 878–896. doi:10.1038/s41422-022-00685-z. PMC 9525306. PMID 35821092.
  94. ^ a b Hettel, Gene (November 18, 2016). "IR8—a rice variety for the ages". Rice Today. Retrieved December 29, 2023.
  95. ^ Marris, E. (May 18, 2007). "Rice with human proteins to take root in Kansas". Nature. doi:10.1038/news070514-17. S2CID 84688423.
  96. ^ Bethell, D.R.; Huang, J. (June 2004). "Recombinant human lactoferrin treatment for global health issues: iron deficiency and acute diarrhea". Biometals. 17 (3): 337–342. doi:10.1023/B:BIOM.0000027714.56331.b8. PMID 15222487. S2CID 3106602.
  97. ^ a b Debrata, Panda; Sarkar, Ramani Kumar (2012). "Role of Non-Structural Carbohydrate and its Catabolism Associated with Sub 1 QTL in Rice Subjected to Complete Submergence". Experimental Agriculture. 48 (4): 502–512. doi:10.1017/S0014479712000397. S2CID 86192842.
  98. ^ ""Climate change-ready rice". International Rice Research Institute. Archived from the original on October 28, 2012. Retrieved October 31, 2013.
  99. ^ Gautam, Priyanka; et al. (2017). "Nutrient Management for Enhancing Submergence Tolerance in Rice" (PDF). Cuttack, Odisha, India: National Rice Research Institute. p. 3. NRRI Research Bulletin No. 13
  100. ^ Emerick, Kyle; Ronald, Pamela C. (2019). "Sub1 Rice: Engineering Rice for Climate Change". Cold Spring Harbor Perspectives in Biology. 11 (12): a034637. doi:10.1101/cshperspect.a034637. PMC 6886445. PMID 31182543.
  101. ^ a b "Drought, submergence and salinity management". International Rice Research Institute (IRRI). Archived from the original on November 1, 2013. Retrieved September 29, 2013.
  102. ^ a b ""Climate change-ready rice". International Rice Research Institute (IRRI). Archived from the original on March 14, 2014. Retrieved September 29, 2013.
  103. ^ a b c Palmer, Neil (2013). "Newly-discovered rice gene goes to the root of drought resistance". International Center for Tropical Agriculture. Archived from the original on November 3, 2013. Retrieved September 29, 2013.
  104. ^ "Roots breakthrough for drought resistant rice". Phys.org. 2013. Archived from the original on November 2, 2013. Retrieved September 30, 2013.
  105. ^ "Rice Breeding Course, Breeding for salt tolerance in rice, on line". International Rice Research Institute. Archived from the original on May 5, 2017.
  106. ^ "Fredenburg, P. (2007). "Less salt, please". International Rice Research Institute. Archived from the original on November 1, 2013. Retrieved September 30, 2013.
  107. ^ a b "Barona-Edna, Liz (April 15, 2013). "Wild parent spawns super salt tolerant rice". Rice Today. Retrieved January 3, 2024.
  108. ^ a b ""Breakthrough in salt-resistant rice research—single baby rice plant may hold the future to extending rice farming". Integrated Breeding Platform (IBP). 2013. Archived from the original on November 2, 2013. Retrieved October 6, 2013.
  109. ^ Li, Junhua; Zhang, Zeyong; Chong, Kang; Xu, Yunyuan (2022). "Chilling tolerance in rice: Past and present". Journal of Plant Physiology. 268: 153576. Bibcode:2022JPPhy.26853576L. doi:10.1016/j.jplph.2021.153576. PMID 34875419.
  110. ^ Su, J.; Hu, C.; Yan, X.; Jin, Y.; Chen, Z.; et al. (July 2015). "Expression of barley SUSIBA2 transcription factor yields high-starch low-methane rice". Nature. 523 (7562): 602–606. Bibcode:2015Natur.523..602S. doi:10.1038/nature14673. PMID 26200336. S2CID 4454200.
  111. ^ Gerry, C. (August 9, 2015). "Feeding the World One Genetically Modified Tomato at a Time: A Scientific Perspective". Harvard University. Archived from the original on September 10, 2015. Retrieved September 11, 2015.
  112. ^ Luo, Qiong; Li, Yafei; Shen, Yi; Cheng, Zhukuan (March 2014). "Ten years of gene discovery for meiotic event control in rice". Journal of Genetics and Genomics. 41 (3): 125–137. doi:10.1016/j.jgg.2014.02.002. PMID 24656233.
  113. ^ Tang, Ding; Miao, Chunbo; Li, Yafei; Wang, Hongjun; Liu, Xiaofei; Yu, Hengxiu; Cheng, Zhukuan (2014). "OsRAD51C is essential for double-strand break repair in rice meiosis". Frontiers in Plant Science. 5: 167. doi:10.3389/fpls.2014.00167. PMC 4019848. PMID 24847337.
  114. ^ Ahuja, Subhash C.; Ahuja, Uma (2006). "Rice in religion and tradition". 2nd International Rice Congress, October 9–13, 2006. New Delhi: 45–52.
  115. ^ Muhammad, Rosmaliza; Zahari, Mohd Salehuddin Mohd; Ramly, Alina Shuhaida Muhammad; Ahmad, Roslina (2013). "The Roles and Symbolism of Foods in Malay Wedding Ceremony". Procedia - Social and Behavioral Sciences. 101: 268–276. doi:10.1016/j.sbspro.2013.07.200.
  116. ^ Ahuja, Uma; Thakrar, Rashmi; Ahuja, S. C. (2001). "Alcoholic rice beverages". Asian Agri-History. 5 (4): 309–319.
  117. ^ Wessing, Robert (1990). "Sri and Sedana and Sita and Rama: Myths of Fertility and Generation". Asian Folklore Studies. 49 (2): 235–257. doi:10.2307/1178035. JSTOR 1178035.
  118. ^ "Cambodia marks beginning of farming season with royal ploughing ceremony". Xinhua. March 21, 2017. Archived from the original on May 3, 2018. Retrieved December 6, 2021.
  119. ^ "Ceremony Predicts Good Year". Khmer Times. May 23, 2016. Retrieved December 6, 2021.
  120. ^ Sen, S. (July 2, 2019). "Ancient royal paddy planting ceremony marked". The Himalayan Times. Retrieved December 6, 2021.

Further reading