The removal of immature grape bunches, typically for the purpose of decreasing yield. By removing the tiny, immature grapes while they are still green, the vine is induced to put all its energy into developing the remaining grapes. In theory this results in better ripening and the development of more numerous and mature flavour compounds. In the absence of a green harvest, a healthy, vigorous vine can produce dilute, unripe grapes. REF: Wikipedia http://en.wikipedia.org/wiki/Green_harvest (18.05.2006)