Preface

This digest is a complete revision and updating of TPI Crop and Product Digest No. 2, which was published in 1973, and is an attempt to present in a concise form basic data relating to the production and utilisation of most of the root crops of economic importance to countries in the tropics. For quick reference the data are arranged under standard headings and include particulars of growth requirements, planting and harvesting procedures, yield, products and their uses, processing techniques, comments on production and trade, and a bibliography for each crop.

The digest does not claim to be exhaustive or comprehensive. The aim is to provide a ready reference tool, for use particularly by non-specialists, and especially by practical workers in the developing countries concerned with advancing the rural economy. However, it is hoped that in addition it will provide a starting point for specialists and researchers working on these crops or their products.

The reviser has received valuable assistance from many persons and organisations during the preparation of this digest. In particular, he wishes to thank the Librarian and Library staff of TDRI who made available a wide range of services, including a computer search of the main agricultural and food processing data bases, and many other members of the TDRI staff, in particular the late Mrs Daisy Kay and the late Mr D. G. Coursey. Special thanks are due to Drs J. C. Caygill, A. K. Thompson and June Rickard who 'vetted' the manuscript, and to many others who provided advice and assistance on specialist matters. Scientific and technical information was obtained from several organizations, including the Royal Botanic Gardens at Kew and at Edinburgh; the Botany Department of the British Museum (Natural History); the University of Hawaii; the University of Idaho, USA; the University of Puerto Rico; the Soybean Center, California, USA; several branches of the United States Department of Agriculture; the Directorate of Agricultural Research, Wageningen, the Netherlands; the Department of Primary Industries, Queensland, Australia; the Central Potato Research Institute, India; the Bangladesh Agricultural Research Institute; the International Potato Center, Lima, Peru; the Caribbean Agricultural Research and Development Institute, Barbados. In addition to production and trade statistics obtainable within TDRI, information was provided by ULG Consultants Ltd. Warwick, UK; Geest Produce Marketing, Spalding, UK; Montego Imports and Exports Ltd. Toronto, Canada; the Barbados Agricultural Society; the Central Marketing Agency,

Trinidad; and a number of individuals concerned in the marketing of tropical root crops. Without the help of these, and of many others, the task of updating this digest would not have been possible.

Reference to trade names of agricultural chemicals, etc. implies no endorsement of the efficacy of these products nor any criticism of competing products not mentioned.