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- 1. In birds, the thin-walled enlargement of
- the digestive tract between the oesophagus
- and stomach. It is an effective storage organ
- especially in seed-eating birds; a pigeon's
- crop can hold about 500 cereal grains.
- Digestion begins in the crop, by the
- moisturizing of food. A crop also occurs in
- insects and annelid worms.
-
- 2. A plant grown for human use. Over 80 crops
- are grown worldwide, providing people with
- the majority of their food, and supplying
- fibres, rubber, pharmaceuticals,
- dyes, and other materials. There are four
- main groups of crops: food crops provide the
- bulk of people's food worldwide. The major
- types are cereals, roots, pulses, vegetables,
- fruits, oil crops, tree nuts, sugar,
- beverages, and spices. Cereals make the
- largest contribution to human nutrition.
- forage crops are crops like grass, clover,
- and kale, which are grown to feed livestock.
- Forage crops cover a greater area of the
- world than food crops. Grass, which dominates
- this group, is the world's most abundant
- crop, though much of it is still in an
- unimproved state. fibre crops produce
- vegetable fibres. Temperate areas produce
- flax and hemp, but the most valuable fibre
- crops are cotton, jute, and sisal, which are
- grown mostly in the tropics. Cotton dominates
- fibre crop production. miscellaneous crops
- include tobacco, rubber, ornamental flowers,
- and plants which produce perfume,
- pharmaceuticals, and dye. See also catch
- crop.
-