Collaboration of farmers en breeders: Participatory crop improvement in perspective.

Participatory Crop Improvement (PCI) has developed over the past decade as an alternative and complementary breeding approach to Formal Crop Improvement (FCI). In that context, PCI principally aims at more effectively addressing the needs of farmers in marginal areas in developing countries. This paper describes the rationale behind the emerging of the PCI-concept, the first experiences, and its place in a development-context. The relation with in situ conservation of plant genetic resources is briefly described. The paper uses the distinction in PCI between PVS (Participatory Varietal Selection, i.e. participatory selection among varieties and advanced materials) and PPB (Participatory Plant Breeding, i.e. selection within segregating materials). While successful experiences of PVS are reported, the potentials of PPB are still to be explored. Among other issues, this article pays attention to Genotype x Environment interaction: while G x E interaction is recognised as an important issue in plant breeding and a justification for PCI, the implications for the design of selection systems with farmer participation, and, eventually the potential of PPB has only been analysed to a limited extend. Questions in relation to materials, breeding strategies and selection procedures to achieve sufficient progress in the different crops and environments are identified; these will however remain unanswered until more experiences from the field are available