Root and tuber crops are important to agriculture, food security and income for 2.2 billion people in developing countries. These species produce large quantities of dietary energy and have stable yields under difficult environmental conditions. This second edition of is an authoritative treatment of four important root and tuber crops: cassava, sweet potato, yams, and aroids. The same format is followed for each crop: Origin and History, Taxonomy and Botany, Breeding and Genetics, Developmental Physiology, Agronomy, Pests and Diseases, Post-Harvest Quality and Marketing. This new edition reviews the scientific literature produced during the last decade and presents major technical advancements. Modern molecular tools have been used to clarify the phylogeny, taxonomy and origin of these species. Similar advances have been made in physiology, agronomy, pathology and product chemistry. It is essential reading for students, researchers and horticulturists.