VARIETIES TO CHOOSE FOR SUSTAINABLE AGRIC ULTURE

Production-oriented cropping systems are strongly discussed both for e conomic and environmental concerns. Agronomists are currently developp ing new cropping systems, by reducing costs of production, by optimizi ng nitrogen and water management, by promoting non chemical control of pests, weeds and diseases. But, in these studies, the choice of genot ypes is restricted by the commercial availability. Plant breeders coul d contribute more to the sustainability of agricultural production thr ough the selection of genotypes characterized as follows: low nitrogen and water requirements, strong depolluting functions, drought-toleran t or escaping water deficit periods, multi-resistant to diseases, adap ted to mechanical control or more competitive against weeds. This desi rable evolution of ideotypes will cause some difficulties to the seed business.