Introduction to Rice
Rice, a cereal grass. Its grain is a leading source of food for more than half the world's population. More than 90 per cent of the world rice crop is harvested in Asia, with China and India being the leading producers. The crop in the United States is relatively small.
Rice is not mentioned in the Bible, but Chinese records indicate that it was raised 5,000 years ago. European rice was first harvested in Italy, in 1468. The first American rice was planted in South Carolina, with seed imported from Madagascar, in 1685.
The Rice Plant
The rice plant is probably native to India. There are some 10,000 varieties, differing in flavor, shape, size, and color of the grains. Under cultivation the plant looks much like barley or oats. Rice is an erect annual, about four feet (120 cm) tall, with smooth tapering leaves that are enclosed in sheaths. The leaves are one-half inch (1.3 cm) wide and up to two feet (60 cm) long. The plant has several stalks at the end of which are smaller stalks called panicles on which grow spikelets. Several grains grow within each spikelet. A grain has a hard outer covering called a hull. Beneath the hull are layers of bran that cover the endosperm (the starchy portion of the rice) and the embryo (the part of the grain from which the new plant develops).
The rice plant grows up to four feet tall with smooth tapering leaves enclosed in sheaths.Two types of rice are cultivated: lowland, or wet, grown on land flooded with water; and upland, or dry, grown similarly to other grains. More than 90 per cent of the world's production consists of lowland rice. Lowland rice is not a water plant, but it will tolerate large amounts of water. The reason it is grown in water is to protect it from weeds.
Rice grows best in tropical or semitropical climates where temperatures never fall below 77 F. (25 C). However, rice will also grow well in colder regions. Usually there are two or three crops per year.
Growing and Processing
CultivatingMethods of rice growing range from the most primitive to the most advanced types of agriculture. In much of Asia rice is still grown as it has been for thousands of years. In the United States, Japan, and some parts of Europe rice cultivation is highly mechanized.
In southern Asia rice is generally raised in small paddies (fields flooded for the growing season). Paddies may be on flat ground or may be terraces cut into the side of a hill or mountain. After the paddies have been flooded, they are plowed with water buffalo or the soil is worked with hoes. In some regions the rice is sown broadcast. In others, young plants are raised in nursery plots and then transplanted in the paddies by hand. More and more water is admitted to the paddies as the plants grow. When the plants begin to ripen, the paddies are drained. The ripened grain is harvested with sickles or knives, and the rice is tied in bundles and stacked to dry.
In the United States rice is drilled into fields and covered with up to two inches (5 cm) of water, or it is sown by airplanes after the fields have been flooded. More water is admitted to the fields as the plants grow, and the fields are drained when the plants begin to ripen. When ripe, the grain is harvested with combines.
MillingRice grains are separated from the panicles by threshing. The inedible hulls are then removed by grinding, cracking, or pounding. The grain thus obtained is brown rice and is the kind eaten in Asia. Since brown rice soon becomes rancid, in the Far East the hull is not removed until shortly before the rice is to be eaten. Rice with the hull still on is sometimes called rough, or paddy, rice. Rice intended for consumption in western countries is most often processed further to make it white. First, the bran layers are removed by rubbing. Then the grains are polished, using talc, chalk, or glucose as an abrasive. Polished rice can be stored for long periods, but lacks vitamins since they are contained in the bran.
Parboiled rice is prepared by treating the grain with steam and pressure before milling The steam and pressure drive into the grains some of the nutrients that would otherwise be lost in milling. Pre-cooked rice is milled rice that has been cooked and dehydrated.
Enemies of Rice
One of the most destructive insect pests of rice is the rice weevil, which eats the grains both in the field and in storage. The rice stem borer, a caterpillar, destroys rice fields. Stunt, a virus disease that dwarfs rice plants and reduces their production, has caused famines in eastern Asia.
Hoja blanca (Spanish for "white leaf") is a virus disease introduced into the United States from Latin America in 1958 and 1959. This disease turns the leaves white, injures the spikelets, and cuts the yield 80 per cent or more.
Uses of Rice
Although it is not as rich in protein as other cereals, rice is nevertheless an excellent food. It has a high carbohydrate content and contains valuable vitamins and minerals. Since most of the vitamins are concentrated in the bran layers of the grain, polished rice is less nutritious than brown rice and parboiled rice. An exclusive diet of polished rice often causes beriberi, a deficiency disease resulting from lack of B-complex vitamins.
Rice is the most important single food throughout much of Asia and in some places makes up 70 to 80 per cent of the food of the people. In the United States much rice is eaten in the form of breakfast cereals. Steamed or fluffy rice is often served as a side dish.
Rice bran is used to feed cattle and poultry. Oil extracted from the bran is used in cooking. Rice straw is used to make shoes, rope, roof thatching, and hats. It is also used as roughage and bedding for cattle. The hulls are used for fertilizer and in the manufacture of synthetic materials. Some products made from the grain are flour, starch, beer, and a wine called sake.
Wild Rice
Wild rice (also called Indian rice) is not a true rice, but is more closely related to barley. It is a wild annual grass found growing in shallow water and in soft mud of freshwater lakes and rivers. The plant may reach nine feet (2.7 m) in height. The leaves, which are flat and pointed, can grow more than three feet (90 cm) in length and about two inches (5 cm) in width. The edible grains are borne in clusters on top of a long stalk. Wild rice is a good source of protein. It is an important source of food for such animals as ducks, geese, and deer.
Wild rice is native to the region extending from southeastern Manitoba eastward to the Atlantic and as far south as Florida. However, almost all harvested wild rice comes from California, Minnesota, and Canada. It is usually harvested and processed by machines similar to those used for true rice. Indians, who have harvested wild rice for centuries, still usually use hand methods.
True rice is Oryza sativa; wild rice is Zizania aquatica. Both are of the grass family, Gramineae.