Quels rapports entre tournesols, santé publique et territoires ? - Proposition d’un tableau de bord pour la gestion concertée de l’ambroisie (Ambrosia artemisiifolia L.)

The ragweed (Ambrosia artemisiifolia L.) is usually known by farmers as a detrimental weed in spring crops, especially sunflower. But it is also known more generally as a public health issue due to its allergenic pollen. The fight against ragweed implies new methods out of the scope of those usually used by agronomists. It does not concern only the cultivated field but the whole territory, not only the farmers but a group of actors not always sharing the same point of view. In order to deal with this complex situation, we built a monitoring dashboard and tested it in the context of a small territory near Lyon (France). This tool allowed the local decision makers to be informed about the management practices, the measures implemented, and their efficiency. The assessments made in 2005 and 2007 usefully highlighted some critical points, such as the management of inter cropping periods on agricultural areas. This monitoring methodology faces some practical problems and still needs to be improved. However, it presents several advantages : the adaptation to local conditions can complement or provide an alternative to approaches based only on regulation. The lessons learned at the local level in the context of this pilot operation can also lead to a global improvement of ragweed control methods.