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53-402: The islands cover 564.30 square kilometres (220 sq mi) in area and supported a population of 16,664 at the 2010 Census, which had increased to 26,870 at the 2020 Census; the official estimate as at mid 2023 was 30,837. The most significant town is Pati, on Moa. Industries include the cultivation of rice , coconut palms and tobacco , animal husbandry , and fishing . Letti proper,

106-403: A branched inflorescence which arises from the last internode on the stem. There can be up to 350 spikelets in a panicle, each containing male and female flower parts ( anthers and ovule ). A fertilised ovule develops into the edible grain or caryopsis . Rice is a cereal belonging to the family Poaceae . As a tropical crop, it can be grown during the two distinct seasons (dry and wet) of

159-514: A location in Maluku Province is a stub . You can help Misplaced Pages by expanding it . Rice Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population , particularly in Asia and Africa . Rice is the seed of the grass species Oryza sativa (Asian rice)—or, much less commonly, Oryza glaberrima (African rice). Asian rice

212-563: A population of 3,546 at the 2020 Census. Lakor , the easternmost island, covers 112.60 km and had a population of 2,865 in mid 2023. The Letti Islands are part of the Banda Sea Islands moist deciduous forests ecoregion. The Leti language , a member of the Austronesian languages group, is spoken on Letti islands. The Letti Islands form the Letti, Lakor and Moa Lakor districts of

265-411: A role in various religions and traditions, such as in weddings . The rice plant can grow to over 1 m (3 ft) tall; if in deep water, it can reach a length of 5 m (16 ft). A single plant may have several leafy stems or tillers . The upright stem is jointed with nodes along its length; a long slender leaf arises from each node. The self-fertile flowers are produced in a panicle ,

318-413: A salt concentration expressed in electric conductivity (EC) of 2, 4, 8, 12, 16, 20 and 35 dS/m. The range of EC values is obtained by mixing fresh water with the appropriate amount of seawater having a salinity corresponding to an EC value of about 50 dS/m. After planting, crops were allowed to germinate under fresh water conditions before the salt treatment started. The soil salinity is expressed in

371-506: A single domestication event for O. sativa . Both indica and japonica forms of Asian rice sprang from a single domestication event in China from the wild rice Oryza rufipogon . Despite this evidence, it appears that indica rice arose when japonica arrived in India about 4,500 years ago and hybridised with another rice, whether an undomesticated proto- indica or wild O. nivara . Rice

424-440: A wide variety of pests including insects, nematodes, rodents such as rats, snails, and birds. Major rice insect pests include armyworms, rice bugs , black bugs , cutworms, field crickets, grasshoppers, leafhoppers, mealybugs, and planthoppers. High rates of nitrogen fertiliser application may worsen aphid outbreaks. Weather conditions can contribute to pest outbreaks: rice gall midge outbreaks are worsened by high rainfall in

477-436: Is rainfed like wheat or maize. Across Asia, unmilled rice or "paddy" (Indonesian and Malay padi ), was traditionally the product of smallholder agriculture, with manual harvesting . Larger farms make use of machines such as combine harvesters to reduce the input of labour. The grain is ready to harvest when the moisture content is 20–25%. Harvesting involves reaping , stacking the cut stalks, threshing to separate

530-661: Is 69% water, 29% carbohydrates , 2% protein , and contains negligible fat (table). In a reference serving of 100 grams (3.5 oz), cooked white rice provides 130 calories of food energy , and contains moderate levels of manganese (18% DV), with no other micronutrients in significant content (all less than 10% of the Daily Value ). In 2018, the World Health Organization strongly recommended fortifying rice with iron , and conditionally recommended fortifying it with vitamin A and with folic acid . Golden rice

583-613: Is a major food staple in Asia, Latin America, and some parts of Africa, feeding over half the world's population. However, a substantial part of the crop can be lost post-harvest through inefficient transportation, storage, and milling. A quarter of the crop in Nigeria is lost after harvest. Storage losses include damage by mould fungi if the rice is not dried sufficiently. In China, losses in modern metal silos were just 0.2%, compared to 7–13% when rice

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636-498: Is a variety produced through genetic engineering to synthesize beta-carotene , a precursor of vitamin A, in the endosperm of the rice grain. It is intended to be grown and eaten in parts of the world where Vitamin A deficiency is prevalent. Golden rice has been opposed by activists, such as in the Philippines . In 2016 more than 100 Nobel laureates encouraged the use of genetically modified organisms , such as golden rice, for

689-581: Is based on four principles: biodiversity, host plant resistance, landscape ecology, and hierarchies in a landscape—from biological to social. Farmers' pesticide applications are often unnecessary. Pesticides may actually induce resurgence of populations of rice pests such as the brown planthopper , both by destroying beneficial insects and by enhancing the pest's reproduction. The International Rice Research Institute (IRRI) demonstrated in 1993 that an 87.5% reduction in pesticide use can lead to an overall drop in pest numbers. Farmers in China, Indonesia and

742-508: Is found for the onion variety "Red" which classifies as slightly sensitive. All crops classify in the range from very sensitive over sensitive to slightly sensitive. There is no crop classified as tolerant, not even moderately tolerant. In the Texel report, also the Van Genuchten-Gupta model (giving an S-curve) was used to find the soil salinity at the 90% yield point. The rationale for this

795-504: Is from Asia. The average world yield for rice was 4.7 metric tons per hectare (2.1 short tons per acre), in 2022. Yuan Longping of China's National Hybrid Rice Research and Development Center set a world record for rice yield in 1999 at 17.1 metric tons per hectare (7.6 short tons per acre) on a demonstration plot. This employed specially developed hybrid rice and the System of Rice Intensification (SRI), an innovation in rice farming. Rice

848-404: Is not affected by soil salinity while beyond it the yield starts declining. The model is fitted to the data by piecewise linear regression. ^ ) Many variety names are uncommon as they consist of 3 letters only *) It is not known what the results would have been if the planting was not done under fresh water conditions but in saline conditions. ) Graphs with scatter plots are shown in

901-797: Is sister to the bamboos, Bambusoideae , and the cereal subfamily Pooideae . The rice genus Oryza is one of eleven in the Oryzeae; it is sister to the Phyllorachideae . The edible rice species O. sativa and O. glaberrima are among some 300 species or subspecies in the genus. other grasses (inc. the C4 grasses , maize , sorghum ) Streptogyneae Ehrharteae Phyllorachideae Wild rices inc. Zizania other rice species and subspecies O. sativa (Asian rice) O. glaberrima (African rice) Bambusoideae (bamboos) Pooideae (grasses and cereals inc. wheat , barley ) Oryza sativa rice

954-685: 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

1007-438: Is subjected to a steaming process before it is milled. This makes the grain harder, and moves some of the grain's vitamins and minerals into the white part of the rice so these are retained after milling. Rice does not contain gluten , so is suitable for people on a gluten-free diet . Rice is a good source of protein and a staple food in many parts of the world, but it is not a complete protein as it does not contain all of

1060-406: Is to flood the field to a depth of 5 cm (2 in), then to let the water level drop to 15 cm (6 in) below surface level, as measured by looking into a perforated field water tube sunk into the soil, and then repeating the cycle. Deepwater rice varieties tolerate flooding to a depth of over 50 centimetres for at least a month. Upland rice is grown without flooding, in hilly or mountainous regions; it

1113-471: Is used as a model organism in biology. Dry rice grain is milled to remove the outer layers; depending on how much is removed, products range from brown rice to rice with germ and white rice. Some is parboiled to make it easy to cook. Rice contains no gluten ; it provides protein but not all the essential amino acids needed for good health. Rice of different types is eaten around the world. Long-grain rice tends to stay intact on cooking; medium-grain rice

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1166-652: The Southwest Maluku Regency within Maluku Province . The office of the district head ( camat ) of Letti is located in Serwaru, on the northern coast of Letti. The office of the camat of Moa Lakor is located in Weet on Moa. The office of the camat of Lakor is located in Wewawan on Lakor. 8°10′44″S 127°56′29″E  /  8.178868°S 127.941284°E  / -8.178868; 127.941284 This article about

1219-440: The essential amino acids in sufficient amounts for good health. World trade figures are much smaller than those for production, as less than 8% of rice produced is traded internationally. China, an exporter of rice in the early 2000s, had become the world's largest importer of rice by 2013. Developing countries are the main players in the world rice trade; by 2012, India was the largest exporter of rice, with Thailand and Vietnam

1272-478: The 21st century as people in Asia and elsewhere ate less grain and more meat. An exception is Sub-Saharan Africa, where both per capita consumption of rice and population are increasing. Rice is a commonly-eaten food around the world. The varieties of rice are typically classified as short-, medium-, and long-grained. Oryza sativa indica varieties are usually long-grained; Oryza sativa japonica varieties are usually short- or medium-grained. Short-grain rice, with

1325-688: The Americas by the Spanish. In British North America by the time of the start of the American War of Independence , rice had become the fourth most valuable export commodity behind only tobacco, wheat, and fish. In 2021, world production of rice was 787 million tonnes , led by China and India with a combined 52% of the total. This placed rice fourth in the list of crops by production, after sugarcane , maize , and wheat . Other major producers were Bangladesh , Indonesia and Vietnam . 90% of world production

1378-460: The Philippines have traditionally managed weeds and pests by the polycultural practice of raising ducks and sometimes fish in their rice paddies. These produce valuable additional crops, eat small pest animals, manure the rice, and in the case of ducks also control weeds. Rice plants produce their own chemical defences to protect themselves from pest attacks. Some synthetic chemicals, such as

1431-531: The USDA Agriculture Handbook No. 60, 1954 is that the classes are narrower with steps of 2 dS/m instead of 4. The Salt Farm Texel uses the Maas–Hoffman model for crop response to soil salinity. The model uses a response function starting with a horizontal line connected further on to a downward sloping line. The connection point is also called threshold or tolerance. Up to the threshold the crop

1484-818: The University of California at Davis has grown barley irrigated with pure seawater and obtained half the normal yield per acre, i.e. half of the average yield per acre at national level. The experiment was conducted at Bodega Bay, North of San Francisco, in a laboratory on the Pacific Ocean. Liu Shiping's team at Yangzhou University created rice varieties that can be grown in salt water, and achieve yields of 6.5 to 9.3 tons per hectare. As of 2021, seawater rice had been planted on 400,000 ha (990,000 acres) in soils with up to 4 grams of salt per kilogram, with yields averaging 8.8 tons per hectare, according to Qingdao Saline-Alkali Tolerant Rice Research and Development Center. In

1537-411: The aim to grow fodder crops. A trial was made by Glenn et al. to use halophytes for feeding of sheep and it was concluded that the animals thrived well. Setting the yield of an alfalfa (lucerne) fodder crop irrigated with fresh water (2 kg/m ) at 100%, the following results were obtained for the yield of halophytic crops irrigated with seawater: After selecting the most salt tolerant cultivar ,

1590-465: The benefits these could bring. In 2022, greenhouse gas emissions from rice cultivation were estimated at 5.7 billion tonnes CO2eq, representing 1.2% of total emissions. Within the agriculture sector, rice produces almost half the greenhouse gas emissions from croplands , some 30% of agricultural methane emissions , and 11% of agricultural nitrous oxide emissions. Methane is released from rice fields subject to long-term flooding, as this inhibits

1643-506: The crop would be lost under these conditions. In the Po Valley in Italy, the arborio and carnaroli risotto rice varieties have suffered poor harvests through drought in the 21st century. The Ente Nazionale Risi  [ it ] is developing drought-resistant varieties; its nuovo prometeo variety has deep roots that enable it to tolerate drought, but is not suitable for risotto. Rice yield can be reduced by weed growth, and

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1696-423: The electric conductivity of the extract of a saturated soil paste (ECe in dS/m). Author Schleiff presented a classification of salt tolerance of crops based on ECe in dS/m that may be summarized as follows: ^) The crop performs well (no yield reduction) up to the soil salinity level listed in the table. Beyond that level, the yield goes down. The main difference with the classification published by Richards in

1749-425: The exception of Spanish Bomba, is usually sticky when cooked, and is suitable for puddings. Thai Jasmine rice is aromatic, and unusually for a long-grain rice has some stickiness, with a soft texture. Indian Basmati rice is very long-grained and aromatic. Italian Arborio rice , used for risotto , is of medium length, oval, and quite sticky. Japanese sushi rice is a sticky short-grain variety. Cooked white rice

1802-706: The feasibility. The government of the Netherlands reports a breakthrough in food security as specific varieties of potatoes, carrots, red onions, white cabbage and broccoli appear to thrive if they are irrigated with salt water. The Salt Farm Texel, a farm on the island of Texel , The Netherlands, is testing the salt tolerance of crops under controlled field conditions. There are 56 experimental plots of 160 m each that are treated in eight replicas with seven different salt concentrations. These concentrations are obtained with intensive daily drip irrigations of 10 or more mm (i.e. more than 10 liter per m per day) with water having

1855-425: The field where they will grow, or seedlings can be grown in a seedbed and transplanted into the field. Direct seeding needs some 60 to 80 kg of grain per hectare, while transplanting needs less, around 40 kg per hectare, but requires far more labour. Most rice in Asia is transplanted by hand. Mechanical transplanting takes less time but requires a carefully-prepared field and seedlings raised on mats or in trays to fit

1908-503: The grain, and cleaning by winnowing or screening . The rice grain is dried as soon as possible to bring the moisture content down to a level that is safe from mould fungi. Traditional drying relies on the heat of the sun, with the grain spread out on mats or on pavements. The edible rice species are members of the BOP clade within the grass family, the Poaceae . The rice subfamily, Oryzoideae ,

1961-478: 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. Crop tolerance to seawater Crop tolerance to seawater is the ability of an agricultural crop to withstand the high salinity induced by irrigation with seawater , or a mixture of fresh water and seawater. There are crops that can grow on seawater and demonstration farms have shown

2014-575: The herbicide 2,4-D , cause the plant to increase the production of certain defensive chemicals and thereby increase the plant's resistance to some types of pests. Conversely, other chemicals, such as the insecticide imidacloprid , appear to induce changes in the gene expression of the rice that make the plant more susceptible to certain pests. Plant breeders have created rice cultivars incorporating resistance to various insect pests . Conventional plant breeding of resistant varieties has been limited by challenges such as rearing insect pests for testing, and

2067-410: The later years of the 20th century decreased rice yield by between 10% and 20% across 200 farms in seven Asian countries. This may have been caused by increased night-time respiration. IRRI has predicted that Asian rice yields will fall by some 20% per 1°C rise in global mean temperature. Further, rice is unable to yield grain if the flowers experience a temperature of 35 °C or more for over one hour, so

2120-417: The machine. Rice does not thrive if continuously submerged. Rice can be grown in different environments, depending upon water availability. The usual arrangement is for lowland fields to be surrounded by bunds and flooded to a depth of a few centimetres until around a week before harvest time; this requires a large amount of water. The "alternate wetting and drying" technique uses less water. One form of this

2173-428: The other largest exporters. As of 2016, the countries that consumed the most rice were China (29% of total), India, and Indonesia. By 2020, Bangladesh had taken third place from Indonesia. On an annual average from 2020-23, China consumed 154 million tonnes of rice, India consumed 109 million tonnes, and Bangladesh and Indonesia consumed about 36 million tonnes each. Across the world, rice consumption per capita fell in

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2226-428: The report for these two varieties only. They show considerable variation both in Y (Yield) and X (ECe) direction. ) For potato only one comparable value is known in literature, namely for the very sensitive variety white rose having a threshold of 1.7 dS/m ) For barley, in contrast, the U.S. Salinity Laboratory mentions a threshold value of ECe = 8 dS/m, which makes it a tolerant crop The highest tolerance

2279-812: 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

2332-1011: The soil from absorbing atmospheric oxygen, resulting in anaerobic fermentation of organic matter in the soil. Emissions can be limited by planting new varieties, not flooding continuously, and removing straw. It is possible to cut methane emissions in rice cultivation by improved water management, combining dry seeding and one drawdown, or executing a sequence of wetting and drying . This results in emission reductions of up to 90% compared to full flooding and even increased yields. Predictions of climate change's effects on rice cultivation vary. Global rice yield has been projected to decrease by around 3.2% with each 1°C increase in global average temperature while another study predicts global rice cultivation will increase initially, plateauing at about 3°C warming (2091–2100 relative to 1850–1900). The impacts of climate change on rice cultivation vary across geographic location and socioeconomic context. For example, rising temperatures and decreasing solar radiation during

2385-677: The voyage to the rest of the Pacific. It reached Austroasiatic and Kra-Dai -speakers in Mainland Southeast Asia and southern China by 5000 years ago. Rice spread around the rest of the world through cultivation, migration and trade, eventually to the Americas as part of the Columbian exchange after 1492. The now less common Oryza glaberrima (African rice) was independently domesticated in Africa around 3,000 years ago, and introduced to

2438-522: The westernmost island, covers 90.10 km and had a population of 9,019 in mid 2023. The island is a triangular mountain ridge, subtended by Koli Besar mountain in the east and the Rapat mountains in the west. Moa , the central and largest island, covers 361.60 km and had a population of 18,953 in mid 2023. The town of Tiakur is the administrative centre for the Regency; it has an area of 45.43 km and had

2491-785: The wet season, while thrips outbreaks are associated with drought. Rice blast , caused by the fungus Magnaporthe grisea , is the most serious disease of growing rice. It and bacterial leaf streak (caused by Xanthomonas oryzae pv. oryzae ) are perennially the two worst rice diseases worldwide; they are both among the ten most important diseases of all crop plants. Other major rice diseases include sheath blight (caused by Rhizoctonia solani ), false smut ( Ustilaginoidea virens ), and bacterial panicle blight ( Burkholderia glumae ). Viral diseases include rice bunchy stunt, rice dwarf, rice tungro , and rice yellow mottle. Crop protection scientists are developing sustainable techniques for managing rice pests. Sustainable pest management

2544-539: The year provided that sufficient water is made available. It is normally an annual, but in the tropics it can survive as a perennial , producing a ratoon crop. Like all crops, rice depends for its growth on both biotic and abiotic environmental factors. The principal biotic factors are crop variety, pests , and plant diseases . Abiotic factors include the soil type, whether lowland or upland, amount of rain or irrigation water, temperature, day length , and intensity of sunlight. Rice grains can be planted directly into

2597-460: 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

2650-465: Was first domesticated in China 9,000 years ago, by people of Neolithic cultures in the Upper and Lower Yangtze , associated with Hmong-Mien -speakers and pre-Austronesians , respectively. The functional allele for nonshattering , the critical indicator of domestication in grains, as well as five other single-nucleotide polymorphisms , is identical in both indica and japonica . This implies

2703-505: Was introduced early into Sino-Tibetan cultures in northern China by around 6000 to 5600 years ago, and to the Korean peninsula and Japan by around 5500 to 3200 years ago. It was also carried into Taiwan by the Dapenkeng culture by 5500 to 4000 years ago, before spreading southwards via the Austronesian migrations to Island Southeast Asia , Madagascar , and Guam , but did not survive

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2756-464: Was not given. The Mediterranean Agronomic Institute, Valenzano, Bari, Italy South coast grew 5 cultivars of lentil irrigated with sea water of different salinity levels. Saline water was prepared by mixing fresh water (EC = 0.9 dS/m) with sea water (EC = 48 dS/m) to achieve salinity levels of 3.0, 6.0, 9.0 and 12.0 dS/m. Some of the results are shown in the following table: Halophytes , or salt-loving plants, can be irrigated with pure seawater with

2809-439: Was stored by rural households. The dry grain is milled to remove the outer layers, namely the husk and bran . These can be removed in a single step, in two steps, or as in commercial milling in a multi-step process of cleaning, dehusking, separation, polishing, grading, and weighing. Brown rice only has the inedible husk removed. Further milling removes bran and the germ to create successively whiter products. Parboiled rice

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