Ratooning (a cropping system characterized by the harvesting of plant regrowth from basal buds) has been practised with several tropical and subtropical field crops since time immemorial. However, it is only since the 1930s that this minor cropping system has been gradually made the subject of systematic research. Pre-contemporary ratooning of rice has been considerably varied in setting, method, intensity, productivity; overall it seems to have declined in importance, although it took root in several areas outside the cradles of rice cultivation (probably as an independent invention) up to at least the 19th century. Currently rice ratooning occurs in Asian, American and African areas. The more interesting data available concern Kenya, Colombia and particularly, China.