About the Website. The website is presented by the Root and Tuber Crops Section of the International Society for Horticultural Science. Members of this section represent some of the leading authorities in the world on their respective crop(s). The purpose of the website is to provide information that is of use to individuals conducting research on or are interested in root and tuber crops. The information provided includes: the botanical binomial for each of the crops was well as the common name(s) in 16 languages, the plant part consumed and method of preparation; photographs of individual crops; and links to other sites of interest.

What are Root and Tuber Crops? There are approximately 400 vegetable crops (including root and tuber crops) that are commercially cultivated worldwide (Kays and Silva Dias, 1996). The term “root and tuber crops” is a very general "catch-all" for a wide cross-section of subterranean storage organs of which there are approximately 38 root, 23 tuber, 14 rhizome, 11 corm and 10 bulb crops. Crops with an enlarged pseudostem or stem (e.g., leek, kohlrabi), even when subterranean, are generally not considered within the root and tuber crop category. Likewise, each of the crops included are commercially cultivated and marketed, though in some instances the volume is not great; species that are gathered form the wild are not included. All of the crops are utilized as food though in diverse ways: e.g., as staples, vegetables, sources of industrial products, condiments.

Importance of Root and Tuber Crops. Roots and tubers were critical components in the diet during the early evolution of mankind (~ 5 million years ago). The migration of early hominids from the tropical rainforest to the savannah, a move that is thought to have occurred after Ardipithecus ramidus, had monumental consequences with regard to food availability (Kays and Paull, 2004). Food acquisition became more critical, and “feast and famine” cycles in food availability were common. Roots and tubers comprised significant components of the diet and had the advantage for hunter-gatherer societies in that they were available over extended periods of time due to their ability to be left in situ until needed. Even today, many indigenous populations display a remarkable knowledge of the general biology of the plant material they gather from the wild.

While the predecessor of modern man is often depicted as a hunter, in reality plant products typically represented substantially more than 50% of the diet (Kays, 1997). Since plant remains rarely survive, an indication of the importance of vegetable materials in the diet comes from recent hunter-gatherers. Estimates of up to 80% of the diet being of plant origin (e.g., roots, tubers, fruit, seeds) have been made (Ardrey, 1976). With the advent of agriculture, cultivated root and tuber crops became increasingly critical sources of food with the potato, cassava and sweetpotato representing the 3^rd, 6^th and 7^th most important sources of food for humans worldwide today. World production figures for several of root and tuber crops are listed in the following table.

Use of the Site

The website is open to anyone interested in root and tuber crops. Photographs of individual crops are available for use with the provision that the individual that owns the photograph be cited (e.g., photograph courtesy of S.J. Kays). The individuals that took the original pictures are listed with the photographs. If you have any suggestions for improving the site, corrections of material presented, etc., please do not hesitate to contact us (kaysstan@uga.edu).

Acknowledgements

We would like to acknowledge the invaluable assistance of Betty Schroeder, Lee Ann Kelly and Brenda Willis in developing the website.

References Cited

Ardrey, R. 1976. The Hunting Hypothesis. Atheneum, New York.
FAO. 2003. FAOSTAT Data Base.(http://apps.fao.org/page/collect ions?subset=agriculture). Food and
      Agriculture Organization of the United Nations.
Kays, S.J. 1997. Postharvest Physiology of Perishable Plant Products. Exon Press,
Kays, S.J., and R.E. Paull. 2004. Postharvest Biology. Exon Press, Athens, GA (in press).
Kays, S.J., and J.C. Silva Dias. 1996. Cultivated Vegetables of the World. Exon Press, Athens,GA.