The main cereal crops are wheat, rice, maize (corn), oats, barley, rye, and sorgham.
The following table shows annual production (metric tons) of cereal grains, in 1961, 2005, 2006, and 2007, ranked by 2007 production (FAO 2008).
Wheat, rice, and maize are the top three cereal crops in terms of global production; together wheat, maize, and rice provide about half of the global requirement of calories and protein (Biodiversity International 2007).
Wheat, rye, triticale, oats, barley, and spelt are the cool-season cereals.
The warm-season cereals are grown in tropical lowlands year-round and in temperate climates during the frost-free season.
All but buckwheat and quinoa are true grasses (these two are pseudocereals).
Rice proteins are richer in lysine than other common cereal proteins and for this reason, rice protein is considered to be of better quality.
Cereals are the main source of energy providing about 350 kcal per 100 grams.
Certain other grains, including oats, quinoa, buckwheat, and grain amaranth (Pseudocereal, non-grasses), are very nutritious.
Overconsumption of milled cereals is sometimes blamed for obesity.
Most other cereals are ground into flour or meal, which is milled; the outer layers of bran and germ are removed.
The grain or edible seed of a cereal is known botanically as a caryopsis.
Spring cereals are planted in early springtime and mature later that same summer, without vernalization.
Barley ranks fourth among the cereals in terms of total world production (BarleyWorld 2006).
Cereal crops or grains are used as food for people, as animal feed for livestock and poultry, and as part of industrial processes producing such products as alcohols and oils.
The term grain also is used for the edible seed or fruit of cereal plants.
Barley and rye are the hardiest cereals, able to overwinter in the subarctic and Siberia.
Once the cereal plants have grown their seeds, they have completed their life cycle.
The word "cereal" derives from Ceres, the name of the pre-Roman goddess of harvest and agriculture.
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.
Cereal grains are grown in greater quantities and provide more energy worldwide than any other type of crop; they are therefore staple crops as the basis of a traditional diet.
Human beings have developed numerous cultivars of cereals in order to enhance such aspects as resistance to disease and insects.
Cereal proteins are typically poor in nutritive quality, being deficient in essential amino acid lysine.