ENFIN!

Context and objectives of the solution. Apple tree cultivation represents a world market of 58 million tons and it is also the agricultural production that requires the most pesticides in France. Control of the apple scab disease caused by the fungus Venturia inaequalis (Vi), represents 50% of pesticides sprayed in orchards, i.e. between 15 and 28 per year in dessert apples and between 3 and 8 in cider apples (€25 million for France). The forthcoming withdrawal of many fungicides from the market will lead apple growers to technical dead ends. ENFIN! aims to offer apple growers a technical breakthrough that will greatly reduce the use of fungicides on the basis of two patented inventions. The first invention aims to make the fungus non-virulent. It is based on the observation that the cross between the Vi lineage pathogenic on apples (POMI) and the Vi lineage pathogenic on pyracantha (PYR) generates non-virulent offspring on the apple tree. Since POMI must reproduces every winter, the idea is to cross it with PYR strains by spraying the orchard with PYR strains in the fall, which will lead to the production of non-virulent hybrids. Concerning the second invention, we have discovered that the application of PYR strains in the spring protected young apple leaves from subsequent scab attack in a way that needs to be elucidated. ENFIN! aims to validate and optimise the effectiveness and combination of these two strategies in orchards, to evaluate the risks and to study the acceptability and appropriation by apple growers of this technical breakthrough. Approaches and methodology. Co-constructed with two national technical centres (the Centre Technique Interprofessionnel des Fruits et Légumes, and the Institut Français des Produits Cidricoles), ENFIN! will be validated during three seasons on four french sites in production orchards. The PYR strains will be produced on an industrial scale and two formulation technologies will be compared. Economists will look for the existence of both organisational and cognitive levers for its appropriation. End user. The solution proposed to apple growers will be easy to use, it will consist of simple applications of PYR strains by spraying, without any specific investment. Recommendations for the development of awareness workshops will be proposed to apple growers as well as proposals for public actions. The transfer of the results of ENFIN! will take the form of a licence granted to a start-up to be created, or to a biocontrol industrialist. Relevance and sustainability of the solution. ENFIN! represents a paradigm shift in terms of its innovative mode of action and the disruptive orchard management technique proposed to apple growers. It should make it possible to reduce the inoculum very significantly from one year to the next and sharply reduce the use of the many synthetic molecules in spring. The risks of emergence of pathogenic hybrids will be assessed by geneticists, and the acceptance by apple growers will be studied by economists. Presentation of the consortium. Its strong points are its complementarity and coherence. The collaboration between the actors of fundamental and applied research, in close collaboration with the actors of the transfer of the National Technical Group Tavelure (advisers, technicians of chambers of agriculture and technical groups, experimenters, researchers...) will allow a rapid diffusion of the solution to apple growers. Different research disciplines are represented: pathologists, experimenters, geneticists, socio-economists. The involvement of industrialists in the production and formulation of spores will enable work on a semi-industrial scale towards a rapid deployment of the solution among apple growers