| Kingdom | Plantae |
| Unranked | Angiosperms |
| Unranked | Monocots |
| Order | Poales |
| Family | Poaceae |
| Genus | Oryza |
| Species | O. sativa |
| Binomial name | Oryza sativa |
Other Common Names:
The other common name for rice is paddy.
History
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.Oryza sativa (rice) is one of the most important crops in the world and it provides the main resource of energy for more than half of the world population and is the major food crop in China. Rice is a staple in Asia that has a long history. Rice is a healthy food source that falls in the vegetable category where in China it is eaten alone or with fish.
Plant Description
The rice plant has four principle parts: a fibrous root system, culm (stem), leaves, and panicle (head). The roots, culm, and leaves make up the vegetative part of the plant. The floral part consists of the panicle, spikelets, and flower. Shortly after seed germination, the fibrous root system of the rice plant begins to develop both outward and downward from the plant's base. Finely-branched adventitious roots arise from the lower nodes of the stem (culm). The size and length of the roots vary. Drained conditions are best for good root development that is proportionate to top growth. Maximum root development is reached at the peak of the tillering stage, then begins to decrease, and toward the fruiting stage, almost ceases. The culm is the jointed rice stem that develops from the plumule (primary bud of the seed embryo) and is composed of solid centers and hollow internodes.
At this time, the stem elongates, and nodes, internodes, and panicles develop and are differentiated. Panicle formation starts when all nodes have been formed and internodes begin to elongate. Usually panicles form 3 to 4 weeks before they are noticeable in the field. It takes about 25 to 33 days from internode elongation until the panicle emerges from the plant. The panicle is fairly dense and drooping in most varieties. One flower makes up the spike let, which consists of a rachilla (a small axis) bearing a single floret. The flower includes all the components and parts enclosed by the lemma and palea (hulls).
Range
Native to the tropics and subtropics of Southeast Asia, rice is now cultivated in many localities throughout the world with favorable climatic conditions. More than 90% of the world rice production is in Asia; China and India being the largest producers .
Habitat
Rice cultivation has been carried into all regions having the necessary warmth and abundant moisture favorable to its growth, mainly subtropical rather than hot or cold. Rice is a tropical, subtropical and warm temperate crop, growing best where summer temperatures of 24-25'C prevail and in full sun. Rice mostly cultured on the humid coastal lowlands and deltas of the world.
Cultivation
Rice should be planted on a smooth seedbed. Cover seed 3.7-5 cm, or broadcast in water with airplane. In some countries (as India, Malaya, Philippines, China, Japan, and Spain), rice is transplanted into fields when 25 cm high, spaced 10-20 cm apart in 20-30 cm rows. Plant in very low water and then increase depth. Transplanting makes better use of limited land areas. Tipar (Upland) culture is still found in Sumatra, Thailand, Borneo, and the Philippines. It represents a primitive kind of culture and is of slight overall importance. Rice is sown 3-4 cm deep in holes 15 cm apart on hillsides where no irrigation is possible. Fields are worked as corn fields; crop rotation is practiced with bananas or sugar cane; yields are small. Continuous rice culture depletes soil nutrition and lowers yield. Rotations with soybeans, grain sorghums or small grains, vetch, safflower, field beans, burclover, horsebeans, bananas, sugarcane, cotton, lespedeza, or corn, have been used. Nitrogen to 90 kg/ha was found to increase yields; beyond that no further increase. Potash and phosphorus are used only on the basis of soil tests. All phosphorus and potassium and some nitrogen should be applied at time of seeding; the rest of the nitrogen at mid growing season as a top-dressing. Flood soon afterwards to eliminate weeds. Other fertilizers which are used; as rice straw, rice ash, stable manure, buffalo dung, green manure, fish guano, fish meal, natural manure, and human feces.
Parts Used
The seeds, hull, grains and the bran are used for its commercial and medicinal purposes.
Pests and Diseases
Major rice pests include the brown planthopper, armyworms, the green leafhopper, the rice gall midge, the rice bug, hispa, the rice leaffolder, stemborer, rats, and the weed Echinochloa crusgali. Rice weevils are also known to be a threat to rice crops in the US, PR China and Taiwan. Major rice diseases include Rice Ragged Stunt, Sheath Blight and Tungro. Rice blast, caused by the fungus Magnaporthe grisea, is the most significant disease affecting rice cultivation.
Medicinal Applications
• They are used in the treatment of dyspepsia caused by cereals, infantile lacto-dyspepsia, and regurgitation of milk and breast distension.
• Rice bran is a source of vitamin B, used as a preventative and cure of beriberi.
• The seeds are used in folk medicine for breast cancers, stomach indurations, other tumors, and warts.
• The stem is used for bilious conditions; ash for discharges and wounds, sapraemia in Malaya; infusion of straw for dysentery, gout, and rheumatism.
• The husk is used for dysentery and considered tonic in China.
• Rice cakes are fried in camel's fat for hemorrhoids; rice water is used for fluxes and ulcers and applied externally for gout with pepper.
• Sprouts are used for poor appetite, dyspepsia, fullness of abdomen and chest, and weak spleen and stomach.
• The lye of charred stems (merang, Indonesia) is used as a hair wash and used internally as an abortifacient.
• The boiled rice "greens" can be used as an eye lotion and for use with acute inflammation of the inner body tissues.
• The hulls (husk) of mature rice plants are considered useful for treating dysentery. The hulls of a three-month old rice plant are thought to be diuretic.
• Dried sprouted rice grains were once used as an external medicine to aid in digestion, give tone to muscles, and expel gas from the stomach and intestines.
• Rice water is prescribed by the Pharmacopoeia of India as an ointment to counteract inflamed surface.
Commercial Applications
• Common or starchy types are used in various dishes, cakes, soups, pastries, breakfast foods, and starch pastes; glutinous types, containing a sugary material instead of starch, are used in the Orient for special purposes as sweetmeats.
• Grain is also used to make rice wine, Saki, much consumed in Japan.
• Rice hulls are sometimes used in the production of purified alpha cellulose and furfural.
• Rice straw is used as roofing and packing material, feed, fertilizer, and fuel.
In Thailand, the annual Royal Plowing Ceremony has taken place in front of the Grand Palace in Bangkok for seven centuries. It's usually held around May, to launch the rice-growing season and is meant to ensure a good bounty. During the rite, the "Lord of the Festival" selects from one of three different-lengths of cloth. Depending on the length, rainfall will be plenty, average or scarce. The Lord then wears that cloth and proceeds to a ploughing area where he pays respect to the King by till in front of him using a pair of bulls and a plough while also scattering rice seeds. After the ceremony, audience members rush onto the field to pick up the sacred grains to take home and mix with their seeds for planting.
Across the sea to Bali, rice seeds are often dropped along the borders of fields to keep evil spirits and animals away. They venerate Dewi Sri, rice goddess of life and fertility. The Balinese will often moisten their chests, foreheads and temples with holy water and stick kernels of uncooked rice to their skin as a way of absorbing Dewi Sri's life force. In some rural villages in Cambodia, you'll come across food offerings in the corners of rice paddies. People believe in a female spirit that guards ancestors as well as resources. To show respect, the farmers pray and offer food - often, sweet rice porridge - to her.
Most of us have either thrown a handful of rice at newly weds or personally experienced a prickly rice shower. This ancient rice throwing ritual originally symbolized fertility and the blessing of many children; today it symbolizes prosperity and abundance. Rice is the first food a new Indian bride offers her husband, perhaps instead of wedding cake; it is also the first food offered a newborn. In Japan where there is an almost mystical aura surrounding the planting, harvesting and preparation of rice it is believed that soaking rice before cooking releases the life energy and gives the eater a more peaceful soul.
To encourage Japanese children to eat all of their rice the grains are affectionately called little Buddha's. In China young girls with inicky appetites are warned that every grain of rice they leave in their rice bowls represents a pock mark on the face of their future husband. In India it is said that the grains of rice should be like two brothers - close, but not stuck together. In China a typical greeting, instead of "How are you?" is "Have you had your rice today?". A greeting to which one is expected to always reply, "Yes".
