| crop gland | Cells in the crop of male and female pigeons and doves that secrete a caseous or milklike material with which the bird feeds its young; it is stimulated to secrete by prolactin, the lactogenic hormone of the anterior hypophysis, and is used as a test object for assaying the activity of this hormone. (05 Mar 2000) |
|---|---|
| crop milk | A secretion formed by glands in the mucosa of the pigeon's crop with which the young are fed; it is increased under the influence of prolactin. Synonym: crop milk. (05 Mar 2000) |
| crop tree | Usually a conifer tree grown to provide wood products. (05 Dec 1998) |
| crops, agricultural | Cultivated plants or agricultural produce such as grain, vegetables, or fruit. (12 Dec 1998) |
| standing crop | The abundance, total weight, or energy content of organisms existing in a specified area at a given time. In relation to plants it usually refers to normal harvesting procedures, unless specified, for the particular plant under consideration and may not necessarily include the entire plant. (09 Oct 1997) |
|---|---|
| energy crop | Crops grown specifically for their fuel value. These include food crops such as corn and sugarcane, and nonfood crops such as poplar trees and switchgrass. Currently, two energy crops are under development: short-rotation woody crops, which are fast-growing hardwood trees harvested in 5 to 8 years, and herbaceous energy crops, such as perennial grasses, which are harvested annually after taking 2 to 3 years to reach full productivity. (05 Dec 1998) |