The technical guidelines are written in a short, direct, sometimes telegraphic style, in order to keep the volume of the document to a minimum and to facilitate updating. The guidelines are divided into two parts. The first part makes general recommendations on how best to move germplasm of the crop concerned and mentions available intermediate quarentine facilities when relevant. The second part covers the important pests and diseases of quarentine concern. The information given on a particular pest or disease does not pretend to be exhaustive but concentrates on those aspects that are most relevante to quarentine. Where possible, acronyms for viruses are according to Hull et. al (1991).

In the last four decades of the twentieth century the use of sweetpotato was diversified beyond their classification as subsistence, food security, and famine-relief crop. In developing countries they serve both as human food and for feeding livestock. In Western countries they appeal to health conscious consumers because of their nutritional aspects. The sweetpotato is very high in nutritive value, and merits wider use on this account alone. The book has 2 parts. A general one giving up-to-date information on the history, botany, cultivars, genetic engineering, propagation, diseases and pests, nutritional data and marketing; and a second part presenting data on sweetpotato growing practices in different areas of the world. The information should be useful to researchers, practitioners and crop administrators in different countries.

Loss of plant diversity: a call for action; List of acronyms and abbrediations; Before setting out; In the field; Back at base; Case-studies.