In 2024 our CNC has tested a growth model, called "Tipstar", for potatoes and especialy Starch potatoes. we evaluate 3 different varieties about growth and nutrient needs of the crop. Tipstar model focuses mainly on Nitrogen and water. With those variables and data generated out of open available sources the optimal yield is estimated. With the constraints given by the farmer about Nitrogen and water it returns a actual yield and gives insight in where the lost yield is found. The evaluation has demstrated that the model is relatively accurate in prediciting the yield (about 5-10 tonnes difference). but that there are some flaws in calculating N out of manure, wich it doesn't calculate but sees as fully mineral nitrogen wich seeps out also in the calculation of the rainfall for specific fields is some flaw, for now it is a broader measurement wich sometimes isn't true due to locally rain. our CNC will test it next year too to get better feeling and hopefully benefit of improvements in data use and model quality.