EN
An Internet model for the assessment of grain loss risk caused by Phaeosphaeria nodorum (syn. Septoria nodorum) is presented in the paper. The model is divided into two functional layers: user interface and calculation layer. Eight factors having a significant impact on the disease development were taken into account: pathogen incidence, stand density, precipitation, the degree of infestation of three top leaves, use of growth regulators, fungicide application dose, controlledtraffic cropping and susceptibility of cultivars. The principle of operation of the model and the method of operating it are presented.