Pratiques agricoles et diversité végétale

The functions of plant diversity are examined from an agronomist's point of view. Species and varieties perform different functions in production process, as well as in the cropping system than in the functionning of the farm system. It is paid particular attention to the interest of varieties. Varied ways of improvement for the future are described in relation to concerns of: quality of the products, extensive cropping and respect of the environnement.