Modelling potato yield losses caused by Phytophthora infestans: Aspects of disease growth rate, infection time and temperature under climate change

Abstract

Modelling crop yield loss due to pathogens remains a challenge due to the complex and dynamic interactions involved. Here, we develop a parsimonious dynamic yield loss simulation model that couples a simple epidemiological model of late blight disease with a basic model of potato crop growth. The model is parameterized using 17 years of field data on disease progress of potato late blight and potato yield in southern Sweden. Simulated actual yields (yields obtained under the presence of Phytopthora infestans) correlated well (R2 = 0.66) with the actual yields observed in field trials, using a few widely accessible meteorological variables. The results also underline the impact of disease growth rate and the time of infection on yield losses, with relatively low rates and early onset of the epidemic producing large yield reductions. In addition, the importance of increasing temperature due to climate change on both potato crop and Phytophthora infestans development was simulated, suggesting that higher temperatures may be more detrimental for the pathogen than for the crop. Additional ways to expand the model are discussed, and the inclusion of other diseases and pests are encouraged, indicating the potential to improve disease management in potato production.