crop

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.

crop

Stubble burning in a Devonshire field. After harvesting the ground is prepared for sowing by burning the corn stubble off in a controlled fire. This practice is controversial as the smoke causes damage to the environment.

Any plant product grown or harvested 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. Crops grown for export are cash crops. A catch crop is one grown in the interval between two main crops.

There are four main groups of crops. Food crops provide the bulk of people's food worldwide. The main types are cereals, roots, pulses (peas, beans), vegetables, fruits, oil crops, tree nuts, sugar, and spices. Cereals make the largest contribution to human nutrition. Forage crops are those such as grass and clover which are grown to feed livestock. Forage crops cover a greater area of the world than food crops. Grasses, which dominate this group, form the world's most abundant crop, consisting mostly of wild species grown 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 that produce perfumes, pharmaceuticals, and dyes.

crop

To cut away unwanted portions of a picture. The term comes from traditional manual methods of layout and paste-up; in computing, cropping is an option made available via photo-finishing and graphics software.