Mobilisation de la connaissance, pour accompagner la transition vers des systèmes de culture gérant les adventices avec moins d’herbicides.

This article is a testimonial from an agronomist advising farmers, describing the interactions between development and research around three themes presented at the end-of-project seminar of the Ecophyto COPRAA project: the production of knowledge on weed control, the development and use of decisionsupport tools, and the participative design of low- or no-herbicide-use systems. This testimonial shows the results of exchanges between the agronomist activity and the research activity of INRAE Dijon team. Three topics in particular are addressed: the mobilization of the product of interactions over time, the use of the FLORSYS mechanistic "virtual-field" model to assess potential changes in weed flora over time, and the design of a tool accessible to farmers through the appropriation and transfer of the knowledge provided. Finally, the article reflects on co-innovation based on the experience of the COPRAA project and highlights the implications for the actors accompanying farmers.