Coupling host and pathogen dynamics to forecast the impacts of Climate Change on brown rust of wheat

摘要: Materials and MethodsThe STICS-MILA coupled model (Caubel et al., 2012) calculates the daily disease severity as the ratio between the photosynthetic inactive leaf surface and the total leaf surface. At a daily time step, STICS (Brisson et al., 2008) provides to MILA input variables about the host plant status (leaf surface, phenological stage, leaf age) and the microclimate into the canopy. MILA feeds back the reduced photosynthetic surface (infectious surface) to STICS, which is deducted from the green surface. The host-pathogen evolution in future climate was then analyzed for recent past (RP: 1950-2000), near future (NF: 2020-2050) and distant future (DF: 2070-2100) periods, considering the A1B scenario of the IPCC. After a prior calibration of the coupled model against field data, the study was performed on durum wheat (cv. Neodur) in three French sites with contrasted climates. The area under the disease progress curve (AUDPC) was calculated as the sum of disease severity (% of total leaf surface area), the sum being done each degree. day between flowering and physiological maturity in order to integrate the disease progress curve during the same length whatever the year. The disease onset was set the 1 st of January with a 100 spores. m-² primary inoculum density.