As head of the Nigerian-based Collaborative Study of Cassava in Africa (COSCA), Nweke (visiting, agricultural economics, Michigan State U.) traces the myths hindering a major African food crop and research yielding new varieties rendering cassava (aka: manioc, tapioca, yucca) a powerful poverty-fighter. Includes tables and figures on production factors, methodological notes, and a list of COSCA reports. Annotation c. Book News, Inc., Portland, OR (booknews.com)