This study of the "dioscorea" genus or yam, consisting of 600 species, is a synthesis of new information. In this world of famine, the yam must play a leading role in the regions it is grown. Its cultivation may even increase once the problems which this book highlights have been resolved.

Part 1 The general morphology of yams: the annual vegetative system; the vegetative reproductive system; the sexual reproductive system. Part 2 The yam tuber - its structure, use and storage: the morphological and anatomical structures of the tuber; bases for the use of the tuber; the tuber's uses; storing the yam tuber in a cool environment. Part 3 Cropping techniques: traditional cropping techniques; industrial yam cultivation. Part 4 The growth and development of yams: clonal generations; flowering and fruiting; growth and development of plants resulting from seeds; pluriannual development. Part 5 Prospects for crop improvement: results from experiments on cropping techniques; protecting crops against pests and parasites; choice of cultivars and varietal creations. Part 6 Systematics, distribution, evolution and phyllogenesis of Dioscoreasceae: the main factors involved in Dioscoreaceae classification; the main groups of food yams; some considerations on the development of the Dioscoreaceae. Part 7 Yams in society: ancient civilizations of the yam; the development of yam-based production systems; production and marketing. Conclusion: Some research proposals; some suggestions for yam research and development.