Our team focuses on plant disease epidemiology, a discipline that aims to study disease development in plant populations. Disease results from the interaction between a pathogen population, a host population, environmental conditions and cultural practices. Understanding this complex interaction requires both experimental and theoretical skills in plant pathology, population genetics, ecology, agronomy, biophysics, biostatistics and modelling. The broad set of skills and collaborations developed by the team scientists reflects this multidisciplinarity which is at the core of our research.

We works on three of the most important wheat fungal diseases in Europe: leaf rust (Puccinia triticina) and stripe rust (Puccinia striiformis) studied in our team since the late 1980s, and septoria leaf blotch (Zymoseptoria tritici) studied for ten years. Through these three biological models, we address the following general questions: "How do diseases develop at different spatiotemporal scales?", "Which life history traits of the pathogen (virulence, aggressiveness, fitness) and external factors (host, climate) influence their dynamics?", "Which management principles and operational means (deployment of varietal resistance, control of inoculum sources) can effectively and sustainably limit their consequences?"

Our research activities focused on the following challenge: improving the effectiveness of varietal resistances (to slow down epidemic development and limiting economic losses) and its sustainability (to slow down the evolution of pathogen populations and prolonging the use of resistances). Interactions between pathogen populations, host populations and environmental conditions are mainly driven by the reproductive regime of the fungal species (clonality for Puccinia sp. vs sexuality for Z. tritici) and selection pressure exerted by the host (species and variety) and climatic conditions (e.g. temperature). The processes involved in the pathogen adaptive dynamics are often specific to time and space scales: plant, plot, territory. Qualitative and quantitative host resistances can be combined at these different scales (pyramiding genes in the same variety, mixing cultivars in a single field, spatio-temporal deployment within a territory).