<The> relationships between cassava variety set characteristics, farmers' food security objectives, environmental and socio-economic conditions in Africa

Hypotheses with respect to the cassava variety selection criteria used by farmers in order to satisfy their food security objectives under various environmental and socio-economic conditions were formulated and tested with data from the Collaborative Study of Cassava in Africa (COSCA). The characteristics of the sets of cassava varieties grown by farmers and their adjustment pattern over time depend mainly on production objectives which are mostly dictated by environmental and socio-economic conditions. Early and late maturing varieties with good ground storability are selected by farmers to bridge the food gap during the hungry season; relatively late maturing varieties with good ground storability and low pest and disease susceptibility are selected to constitute backstop food reserves where the environmental risk of crop failure is a major concern; early maturing varieties with high yield and high dry matter content are selected to adjust to low or declining resource base per capita in high population density or high market demand areas. Farmers in low population density areas of the humid forest zones use in addition, ability to compete effectively with weeds as a major selection criterion. In general the sweet/bitter character of cassava varieties appears to be a less important selection criterion to farmers. eng