Gestion dynamique de la diversité variétale du manioc en Amazonie du Nord-Ouest

Abstract

The dynamic management of varietal diversity in cassava in north-western Amazonia. Based on a case study in a village of the Rio Negro region in Brazilian Amazonia, the article analyses the factors on which the maintenance and renewal of varietal diversity in cassava, the main crop and staple food in the region, are founded. A number of earlier studies, mainly in the social sciences, have shown the wide diversity existing in cassava varieties in several Amerindian or métis groups in Amazonia. This diversity has been mostly explained in terms of ecological advantages, i.e. of polyculture over monocropping. In most cases however, questions relative to identification of this diversity, its social meaning and the associated practices, which are all contribute to a certain type of lifestyle and of relations with the environment, are still unexplored. Our hypothesis as to the random and voluntary nature of the selection process in cassava varieties induced us to focus our study on the technical and socio-cultural aspects involved in the management of this diversity. The study is completed by a genetic analysis of the amplitude and organisation of this diversity. A better understanding of man’s action on this staple crop should enable us to identify the processes involved in the selection and conservation of cassava varieties and their ecological and socio-cultural foundations; assess the different consequences of a decrease in varietal diversity on the local and regional scales, more particularly the consequences linked to the dissemination of improved plant material; take account of the ecological, economic and socio-cultural significance of varietal diversity for local populations in designing conservation policies for genetic resources; and allow indigenous knowledges right of place in the selection processes of a plant material that nowadays is disseminated throughout the tropical world.