grain, in agriculture

grain, in agriculture, term referring to the caryopsis, or dry fruit fruit, matured ovary of the pistil of a flower, containing the seed . After the egg nucleus, or ovum, has been fertilized (see fertilization ) and the embryo plantlet begins to form, the surrounding ovule (see pistil ) develops into a seed and the ovary wall
..... Click the link for more information. , of a cereal grass grass, any plant of the family Gramineae, an important and widely distributed group of vascular plants, having an extraordinary range of adaptation. Numbering approximately 600 genera and 9,000 species, the grasses form the climax vegetation (see ecology ) in great
..... Click the link for more information. . The term is also applied to the seedlike fruits of buckwheat buckwheat, common name for certain members of the Polygonaceae, a family of herbs and shrubs found chiefly in north temperate areas and having a characteristic pungent juice containing oxalic acid. Species native to the United States are most common in the West.
..... Click the link for more information. and of certain other plants and is used collectively for any plant that bears such fruits. The food content of the seeds (as they are commonly called) is mostly carbohydrate, but some protein, oil, and vitamins are also present. Grain, whole or ground into meal or flour, is the principal food of man and of domestic animals. The seeds of most grains grow in concentrated clusters that are gathered efficiently by modern mechanical harvesting machines (see combine combine (kŏm`bīn), agricultural machine that performs both harvesting and threshing operations.
..... Click the link for more information. ). Grain is easy to handle and, because of its low water content, can be stockpiled and stored for long periods, unlike other starch foods (e.g., the potato). Grains, both living and stored, are attacked by a variety of insect pests (e.g., the corn borer, locust, and grasshopper) and by smuts, rusts, blights, rots, and other diseases of plants diseases of plants. Most plant diseases are caused by fungi, bacteria, and viruses. Although the term disease is usually used only for the destruction of live plants, the action of dry rot and the rotting of harvested crops in storage or transport is similar
..... Click the link for more information. . The principal grain crops, in order of total world output, are wheat wheat, cereal plant of the genus Triticum of the family Gramineae ( grass family), a major food and an important commodity on the world grain market.

Wheat Varieties and Their Uses

..... Click the link for more information. , rice rice, cereal grain (Oryza sativa) of the grass family (Graminae), probably native to the deltas of the great Asian rivers—the Ganges, the Chang (Yangtze), and the Tigris and Euphrates.
..... Click the link for more information. , Indian corn corn, in botany. The name corn is given to the leading cereal crop of any major region. In England corn means wheat; in Scotland and Ireland, oats. The grain called corn in the United States is Indian corn or maize (Zea mays).
..... Click the link for more information. (or maize), oats oats, cereal plants of the genus Avena of the family Gramineae ( grass family). Most species are annuals of moist temperate regions. The early history of oats is obscure, but domestication is considered to be recent compared to that of the other
..... Click the link for more information. , barley barley, annual cereal plant (Hordeum vulgare and sometimes other species) of the family Gramineae ( grass family), cultivated by humans probably as early as any cereal.
..... Click the link for more information. , and rye rye, cereal grain of the family Gramineae ( grass family). The grain, Secale cereale, is important chiefly in Central and N Europe. It seems to have been domesticated later than wheat and other staple grains; cultivated rye is quite similar to the wild forms
..... Click the link for more information. ; together, these grains occupy about half of all the land under crops. All the staple grains were domesticated in the Neolithic period, or New Stone Age, and their cultivation was a powerful factor in drawing men into settled communities. Many religious beliefs and rites have been associated with grains; the cereals derive their name from Ceres, the Roman goddess of grain. Grain has been an article of commerce in nearly all civilizations.

Bibliography

See N. L. Kent, Technology of Cereals (1983); Y. Pomerantz, Modern Cereal Science and Technology (1987).

grain, in weights and measures

grain, in weights and measures: see English units of measurement English units of measurement, principal system of weights and measures used in a few nations, the only major industrial one being the United States. It actually consists of two related systems—the U.S.
..... Click the link for more information. .

1.		GRAIN - A pictorial query language. ["Pictorial Information Systems", S.K. Chang et al eds, Springer 1980].
2.		grain - granularity