Résumé
This paper attempts to understand conceptual models on which knowledge and management practices of traditional crop diversity are based and whether these models collide with the knowledge formalized in institutions for agricultural development, or complete them. The originality of the approach is to deal not with knowledge as a body of operational data but with their social meaning and values. It is from this understanding and recognition of mutual contributions of different forms of knowledge that a symmetry of exchange between actors can be considered. The example investigated is that of the slash-and-burn agriculture of the Rio Negro, in the north-western Brazilian Amazon.