Cereal crops are mostly grasses cultivated for their edible seeds (actually a fruit called a grain, technically a caryopsis). Cereal grains are grown in greater quantities worldwide than any other type of crop and provide more calories to the human race. In some developing nations, cereal grains constitute practically the entire diet of common folk. In developed nations, cereal consumption is more moderate but still substantial. The word cereal has its origin in the Roman goddess of grain, Ceres. Staple food grains are often called corn.
The cereal crops are (in approximate order of greatest annual production):
In addition, several non-grasses are grown for their seeds. These pseudocereals include (in no particular order):
While each individual species has its own peculiarities, the cultivation of all cereals crops is similar. All are annual plants; consequently one planting yields one harvest. Wheat, rye, triticale, oats, barley, and spelt are the cool-season cereals. These are hardy plants that grow well in moderate weather and cease to grow in hot weather (approximately 30°C but this varies by species and variety). The other warm-season cereals are tender and prefer hot weather.
Cool-season cereals are well-adapted to temperate climates. Most varieties of a particular species are either winter or spring types. Winter varieties are sown in the autumn, germinate and grow vegetatively, then become dormant during winter. They resume growing in the springtime and mature in late spring or early summer. This cultivation system makes optimal use of water and frees the land for another crop early in the growing season. Winter varieties do not flower until springtime because they require vernalization. Where winters are too warm for vernalization or exceed the hardiness of the crop (which varies by species and variety), farmers grow spring varieties. Spring cereals are planted in early springtime and mature later that same summer, without vernalization. Spring cereals typically require more irrigation and yield less than winter cereals.
Rye is the hardiest cereal, able to overwinter in the subarctic and Siberia. Wheat is the most popular. All cool-season cereals are grown in the tropics, but only in the cool highlands, where it may be possible to grow multiple crops in a year.
The warm-season cereals are grown in tropical lowlands year-round and in temperate climates during the frost-free season.
Cereal grains supply most of their calories as starch. They are also a significant source of protein, though the amino acid balance is not optimal. Whole grains (see below) are good sources of dietary fiber, essential fatty acids, and other important nutrients.
Rice is eaten as cooked entire grains, although rice flour is also produced. Oats are rolled, ground, or cut into bits (steel-cut oats) and cooked into porridge. Most other cereals are ground into flour or meal, that is milled. The outer layers of bran and germ are removed (see grain (fruit) and seed). This lessens the nutritional value but makes the grain more appealing to many palates. Health-conscious people tend to prefer whole grains, which are not milled. Overconsumption of milled cereals is sometimes blamed for obesity. Milled grains do keep better because the outer layers of the grains are rich in rancidity-prone fats. The waste from milling is sometimes mixed into a prepared animal feed.
Once (optionally) milled and ground, the resulting flour is made into bread, pasta, desserts, dumplings, and many other products. Besides cereals, flour is sometimes made from potatoes, chestnuts and pulses (especially chickpeas).
See also: Zadok scale
da:Korn de:Getreide eo:Cerealo fr:Céréale ja:穀物 minnan:Ngó·-kok ms:Bijirin nl:Graan pt:cereal simple:Corn sv:Spannmål es:cereal zh:粮食