Management of crop resistance to diseases in agricultural landscapes as a response to new constraints on pesticide use – Gester

Our central objective is to produce scenarios to allocate resistant varieties at the scale of a cultivated landscape. The scenarios will be evaluated from the point of view of their organizational feasibility as well as their technical performances. The GESTER project is structured as follows: (1) acquisition of knowledge on the strategies of the actors and development of multicriteria decision models; (2) in parallel, acquisition of knowledge on the diseases and development of spatially explicit epidemiological models; (3) use of the models and acquired knowledge to produce «candidate« scenarios; (4) joint evaluation of these «candidate« scenarios by all partners to produce scenarios that are acceptable by the actors and efficient with regards to both biological and operational criteria. The main challenges are the development of models for landscape epidemiology and the development of multiciteria models for evaluating organizational performances.

The projetc is currently in its first phase. At this point, a satisfactory integration of the main disciplinary fields has been achieved. The partners have produced epidemiologic models allowing the simulation of an epidemic at the scale of agricultural landscapes. These models indicate that the way the varieties are distributed over the landscape (grouped or mixed) has an effect on the strenght of the epidemics and on the evolution of the pathogen. Gester has already be an inspiration for new projects (FONDU, funded by INRA, and a project submitted to the Biodiversity Research Funfation)

This project has been identified as an example of collaborative work between agronomy / epidemiology and social sciences, dealing with a central question for the evolution of agriculture (see for instance agriculture.gouv.fr/ecophyto-projet-gester)

scientific paper : Papaïx et al. 2013. PLoS ONE 8(2): e54697. Communication : C. Lannou (2013) Gestion régionale des variétés résistantes (projet Gester). Colloque Ecophyto Recherche, Paris. (http://agriculture.gouv.fr/ecophyto-projet-gester)

A major stake for agriculture is to significantly reduce pesticide applications while maintaining productivity. This will require significant technical but also organisational changes. In this context, the present project is proposed by a pool of research teams representing a large and complementary set of disciplines: epidemiology, agronomy, social sciences and mathematical sciences. Our central objective is to produce scenarios to allocate resistant varieties at the scale of a cultivated landscape. Such scenarios will allow limiting the development of diseases while ensuring the durability of the efficiency of the genetic resistances. The scenarios will be evaluated from the point of view of their organizational feasibility as well as their technical performances. The social representations of the disease by the actors will be considered in order to assess the scenarios’ acceptability. The GESTER project is based on the joint study of two main crop species: wheat and oil seed rape. It is structured as follows: (1) acquisition of knowledge on the strategies of the actors and development of multicriteria decision models; (2) acquisition of knowledge on the diseases and development of spatially explicit epidemiological models; (3) use of the models and acquired knowledge to produce "candidate" scenarios; (4) joint evaluation of these "candidate" scenarios by all partners to produce scenarios that are acceptable by the actors and efficient with regards to both biological and operational criteria; (5) a transversal task will be specifically dedicated to the methodological questions raised by modelling of epidemics on explicit landscapes. The diffusion of the results will be made in particular through the communication supports of the partner Technical Institutes (extension services).