Introduction Of Rice Rice is intimately involved in the culture as well as the food ways and economy of many Societies. Rice is considered as the gift of god, and it is treated with reverence, and its cultivation is tied to elaborate rituals. Chinese myth, by contrast, tells of rice being a gift of animals rather than of gods. Tradition holds that "the precious things are not pearls and jade but the five grains", of which rice is the first. Though sufficient food is produced on global basis to feed everyone, the pains of hunger continue to be a common experience of many people in the world today especially in the developing countries and under developed countries because of the rapid population growth. Among the major cereals, rice is the primary staple food for more than 2 billion people in Asia and hundreds of millions of people in Africa and in Latin America. Rice contains a large amount of starch, some proteins, minerals and vitamins like E and B.

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Origin and Diffusion of Rice From our ancient scripts it is learnt that Indians knew rice before the present era. According to some earlier workers like Decandolle (1886) and Watt (1862) the rice cultivation was originated in the South India. Some other workers like Vavillov suggested that India and Burma are centers of origin of cultivated rice. The origins of rice have been debated for some time, but the plant is of such antiquity that the precise time and place of its first development will perhaps never be known. It is certain, however, that the sub-species Indica is mostly grown in India while in few pockets of Sikkim and in Himalayan regions where cold climate exists and the Japonica varieties are grown. The classification of rice cultivated in India is as follows, Botanical Name Oryzae sativa L Family Gramineae Domestication of rice ranks as one of the most important developments in history, as this grain has fed more people over a longer period of time than any other crop. The earliest settlements might have been near the edge of the uplands, but on gently rolling topography and close to small rivers that provided a reliable water supply. The earliest agriculture had probably focused on plants that reproduced vegetatively, but the seeds of easily shattering varieties of world rice such as Oryzae fatua may have found their way to the gardens at an early date. If these assumptions are correct, then domestication most likely took place in the area of Korat or in some sheltered basin area of northern Thailand, one of the longitudinal valleys of Myanmar's Shan Upland, in southwestern China, or in Assam. Cultivated rices belong to two species, O.sativa and O.glaberrima, of the two, O. sativa is by far the most widely utilized. O. sativa is a complex group composed of two forms, endemic to Africa but not cultivated, and a third from, O. rufipogon, having distinctive partitions into South Asian, Chinese, New Guinean, Australian, and American forms. The subdivision of O. sativa into these seven forms began long ago and came about largely as a result of major tectonic events and world wide climatic changes. It is postulated, based on measurements by electrophorosis, that the Australian form of O.sativa began to diverge from the main forms about 15 million years ago. At that time, during the Miocene, the Asian portion of Gondwanaland collided with the Australia/New Guinea portion, creating a land bridge across which O. sativa migrated. Once the blocks separated, the Australian form was free to follow an evolutionary path somewhat different from the O.sativa on the mainland. Divergence between the South Asian and Chinese forms, the ancestors that are commonly referred today as indica and japonica (or sinica) types, is believed to have commenced 2-3 million years ago. At that time, migration of fauna across the proto-Himalaya was still possible, and with the animals the wild rice was carried. The climate is suitable for rice even today in Central Asia and North China with almost ideal conditions. Botanical evidence concerning the distribution of cultivated species is based chiefly on the range and habitat of wold species that are believed to have contributed to the cultivated forms. The greatest variety of such rices is found in the zone of monsoonal rainfall extending from eastern India through Myanmar, Thailand, Laos, Northern Vietnam and into southern China. This diversity of species, including those considered by many have been involved in the original domestication process, lends support to the argument for mainland southeast Asia as the heartland of rice cultivation. The earliest and most convincing archeological evidence for domestication of rice in Southeast Asia was discovered by Wilhelm G. Solheim II in 1966. Piottery shards bearing the imprint of both grains and husks of O.Sativa were discovered at Non Nok tha in the Korat area of Thailand. These remains have been confirmed by 14C and thermoluminescence testing as dating from at least 4000 B.C. Rice, an annual grass belongs to the genus Oryzae. There are about twenty three species out of which only two species have been known of their commercial value being used for cultivation. These two species are Oryzae sativa (Asian rice) and Oryzae glaberrima (African rice). The Oryzae sativa is the most commonly grown species through out the world today while Oryzae glaberrima is grown only in South Africa. In Asia Oryzae sativa is differentiated into three sub species based on geographical conditions viz., Indica, Japonica and Javanica. Indica refers to the tropical and sub tropical varieties grown throughout South and Southeast Asia and Southern China. The variety Japonica is grown in temperate areas of Japan, China and Korea, while Javanica varieties are grown along side of indicas in Indonesia . Species Oryzae Genus Sativa Sub-species Indica

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Rice Area, Production and Productivity in the World Country Area in Ha. Production in Mt Productivity in Kg/Ha 2003 2004 2003 2004 2003 2004   Australia 18,278,500 17,574,500 38,769,646 31,162,345 2121 1773   Bangladesh 11,618,838 11,729,653 27,650,030 26,607,970 2379 2268   Brazil 19,818,934 20,324,047 63,458,450 59,635,938 3201 2934   Canada 18,288,300 16,929,900 50,174,300 52,680,400 2743 3111   China 77,111,238 80,436,260 322,075,277 354,482,141 4176 4407   India 97,981,000 95,870,000 189,949,299 190,402,999 1938 1986   Indonesia 14,835,868 15,254,794 45,662,221 47,413,464 3077 3108   Kazakhstan 13,706,400 14,026,900 14,676,200 12,255,033 1070 873   Nigeria 21,398,000 21,563,000 21,492,791 21,603,514 1004 1001   Pakistan 12,481,000 12,325,000 26,542,724 28,015,496 2126 2273   Russia 36,759,400 40,493,400 65,411,508 76,074,529 1779 1878   Thailand 11,545,300 11,128,300 22,575,047 22,376,116 1955 2010   USA 57,888,330 56,802,930 345,888,390 385,581,510 5975 6788 World 670,260,914 679,922,070 1,886,862,470 2,062,312,880 2815 3033 Source : FAOstat citation Statewise Area, Production and Productivity of rice in India during 2002 State Area in M Ha. Prodeuciton in Mt Productivity (kg/ha) West Bengal 6.07 15.26 2514 Uttar Pradesh 5.88 12.46 2120 Andhra PRadesh 3.83 11.39 2978 Punjab 2.49 8.82 3545 Orissa 4.50 7.15 1589 Tamilnadu 2.11 6.87 3263 Bihar 3.57 5.28 1480 Chhattisgarh 3.73 5.13 1374 Assam 2.53 3.85 1524 Karnataka 1.42 3.17 2236 Haryana 1.03 2.72 2652 Mahrashtra 1.51 2.65 1751 Madhya Pradesh 1.76 1.66 948 Jarkhand 1.48 1.64 1111 Gujarat 0.66 1.03 1549 Kerala 0.32 0.72 2218 Others 1.75 3.28 @ All India 44.62 93.08 2086 @- since area / production is low, yield rate is not worked out. Source : Department of Agriculture Co-operation. In India, rice accounts for 22 per cent of the total cropped area under cereals. The most significant achievement of the post independent era is the transformation from chronic deficit to self-sufficiency. The per capita net availability of rice (provisional) has increased from about 150 g in 1950 to 225 g in 1990, in spite of growing population. The rice area has shrunk from 2.52 million hectares in 1960 to about 2.20 million hectares in 1998-99, but the production has increased from 3.5 million tonnes to about 8.2 million tonnes in 1998-99 and ranked first in national productivity. Districtwise Area, Production & Productivity of Rice in Andhra Pradesh 2003-04 District Area in Hectares Production in tonnes Yield in Kg/ha 1 2 3 4 Srikakulam 190423 426295 2239 Vizianagaram 113076 239045 2114 Visakhapatnam 88637 144647 1632 East Godavari 399994 1631545 4079 West Godavari 410218 1679723 4095 Krishna 229853 545924 2375 Guntur 176259 499827 2836 Prakasham 46118 121270 2630 Nellore 154916 414124 2673 Chittoor 45781 85276 1863 Cuddapah 34123 84057 2463 Ananthapur 28341 70354 2482 Kurnool 39584 112012 2830 Mahaboobnagar 99496 230606 2318 Rangareddy 36299 85547 2357 Medak 86303 216005 2503 Nizamabad 91370 282358 3090 Adilabad 80920 200748 2481 Karimnagar 187576 602047 3210 Warangal 170235 510766 3000 Khammam 142108 412482 2903 Nalgonda 123008 358144 2912 State 2974638 8952802 3011 Area, Productivity and Production of Rice in Andhra Pradesh from 1999 to 2004 Year Kharif Rabi Total Area in lakh ha Produc-tivity in Kgs/ ha Produ-ction in lakh tonnes Area in lakh ha Produ-ctivity in Kgs/ha Produ-ction in lakh tonnes Area in lakh ha Produ-ctivity in Kgs/ha Produ-ction in lakh tonnes 1 2 3 4 5 6 7 8 9 10 1999-2000 28.49 2529 70.56 11.65 3154 35.82 40.14 2710 106.38 2000-2001 30.04 2741 82.34 12.39 3409 42.24 42.43 2936 124.58 2001-2002 24.26 2679 65.01 13.99 3496 48.89 38.25 2978 113.90 2002-2003 21.09 2397 50.54 7.13 3189 22.73 28.22 2597 73.27 2003-2004 21.09 2772 58.42 8.66 3594 31.11 29.75 3011 89.53 Average of pre-ceding 5 years (1998-99 to 2002-2003) 26.40 2578 67.70 12.04 3312 39.68 38.44 2807 107.38 Source : Department of Agriculture Co-operation. Dietary value In most of the Asian countries, a person eats about 160 kg of husked rice each year or almost 0.5 kg/day. Most rice is consumed in its polished state, and when such rice constitutes a high portion of the food it may lead to dietary imbalance. Non-starch constituents decrease from surface to core in the grain, and polished grain is low in both vitamin B1 and lysine as well as poor in protein. Brown rice is not popular for several reasons like : i) more fuel is needed for cooking; ii) digestive problems and oil found in the bran causes rancidity during storage. Milling removes roughly 80% of the thiamine from brown rice. Parboiling of rough rice before milling is very common in India. A portion of vitamins and minerals is retained in this process. Composition of brown rice, milled (polished) rice and rice bran Constituent Brown rice Milled rice Rice bran Starch (%) 75.90 89.80 9.70 Amylose (%) 30.80 32.70 6.70 Crude fiber (%) 0.80 0.10 9.70 Crude fat (%) 3.30 0.60 22.80 Crude protein (%) 8.40 7.70 15.70 Iron (mg/100g) 2.00 0.67 15.70 Lysine (g/16 g N) 4.10 3.80 5.60 Thiamine (mg/100g) 0.34 0.07 2.26 Riboflavin (mg/100g) 0.05 0.03 0.25 Niacin (mg/100g) 4.70 1.60 29.80

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Early Spread of Rice From an early beginning somewhere in the Asian arc, the process of diffusion has carried rice in all directions until today it is cultivated on every continent save Antarctica. In this early hearth area, rice was grown in forest clearing under a system of shifting cultivation. The crop was grown by direct seeding and without standing water. Rice was grown on "farms" under conditions only slightly different from those to which wild rice was subject. A similar but independent pattern of the incorporation of wild rices into an agricultural system may well have taken place in one or more locations in Africa at approximately the same time. It was in china that the processes of puddling soil and transplanting seedlings were likely refined. Both operations became integral parts of rice farming and remain very widely practiced to this day. Transplanting, like puddling, provides the farmer with the ability to better accommodate the rice crop to a finite water supply by shortening the field duration (since seedlings are grown separately, and a higher density) and adjusting the planting calendar. With the development of puddling and transplanting, rice became truly domesticated. In China, the history of rice valleys and low-lying areas is longer that its history as a dryland crop. In southeast Asia, by contrast, rice was originally produced under dryland conditions in the uplands, and only recently did it come to occupy the vast river deltas. Migrant peoples from South china or perhaps northern Vietnam carried the traditions of wetland rice cultivation to the Philippines during the second millennium B.C. and deutero-Malays carried the practice to Indonesia about 1500 B.C. From china or Korea, the crop was introduced to Japan no later than 100 B.C. Movement to western India and to Sri Lanka was also accomplished very early. The crop may well have been introduced to Greece and neighboring areas of the Mediterranean by the returning members of Alexander the Great 's expedition to India ca. 344-324 B.C. From a centre in Greece and Sicily, rice spread gradually throughout the southern portions of Europe and to a few locations in North Africa. Interestingly enough, medical geographers in the 16th century played an important role in limiting the adoption of rice as a major crop in the Mediterranean area. During the 16th and early 17th centuries, malaria was a major disease in southern Europe, and it was believed to be spread by the bad air (hence the origin of the name ) of swampy areas. Major drainage projects were undertaken in southern Italy, and wetland rice cultivation was discouraged in some regions. In fact, it was actually forbidden on the outs..kirts of a number of large towns. Such measures were a significant barrier to the diffusion of rice in Europe. Carbon dioxide has long been the prime suspect for the green house effect and warming up of earth , but it is now known that, methane traps 20 times more energy. Its agreed that methane concentrations are increasing at the rate of approximately 1% yr. A major methane source, perhaps even the largest of all, is flooded riceland. Not only do methane-producing bacteria thrive in such an environment, but rice plants themselves act as gas vents, putting greater-than-expected concentrations into the atmosphere. The problem is, of course, magnified by the extension of rice area, by the expansion of irrigation facilities, and especially by the enlargement of double-cropped rice areas. Rice fields are suspected of putting 115 million t of methane into the atmosphere each year. This is at least equal to the total production from all of the world's natural swamps and wetlands. Is it possible that agricultural intensification is hastening environmental degradation. As a result of Europe's great Age of Exploration, new lands to the west became available for exploitation. Rice cultivation was introduced to the New World by early European settlers. The Portugeuse carried it to Brazil, and the Spanish introduced its cultivation to several locations in Central and South America. The first record for North America dates from 168. The crop may well have been carried to that area by slaves brought from Madagascar. Early in the 18th century, rice spread to Louisiana, but not until the 20th century was it produced in California's Sacramento Valley. The introduction in the latter area corresponded almost exactly with the timing of the first successful crop in Australia's New South Wales.

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