Understanding yield reduction in rice due to leaf blast

The study described in this thesis focuses on a quantitative understanding of the effect of leaf blast on growth and production of a rice crop, based on insight in the physiological processes underlying damage. For this purpose, experimental research was conducted at two levels of integration: plant and crop. Research was first conducted at the plant level and focused on the effects of the disease on photosynthesis and respiration. To determine the consequences of these physiological disturbances for crop growth and production, submodels for the effects of leaf blast on photosynthesis and respiration were constructed and introduced in a mechanistic model for crop growth. Experimental research at the crop level was used to validate and improve the extended crop growth model. At the same time the model was used to analyse the results of the field experiments. This interaction resulted in a better understanding of yield reduction in rice due to leaf blast and in a model that can be used to estimate yield reduction due to leaf blast for various epidemics under variable environmental conditions.