Potatoes are one of the most important crops in organic farming with respect to farmers’ income. Yields are often strongly influenced by regional and yearly diffe-rences. Despite the availability of detailed knowledge, it is only now that a crop growth model has been generated which allows for the estimation and prediction of potato yield under organic conditions. The aim of our study was to produce a highly elaborate prediction model based on the utilization and speed of nitrogen uptake as they relate to the yield dynamics of tubers and canopy in combination with late blight dynamics. Therefore, from 2005 to 2014, these parameters were assessed in up to 18 varieties of potatoes comprised of differing maturity groups. The data were ana-lyzed in R using similar algorithms to the Grofit package. Our distinct model included updated mathematical functions to estimate the yield development in organic potato-es. Finally, we demonstrate that at a relatively early time in the season it is possible to estimate the yield of potatoes of various varieties and maturity groups
