By means of the methods and apparatuses of the applications of the invention, the harvesting moment for cultivations having better timing with respect to falling numbers, and thus possibly also the order of harvesting of different sites of cultivation are determined by determining a local real-time falling number prediction for each cultivation with a computing program wherein data on the cultivation, data on the site of the cultivation, and local weather data for the site of the cultivation are used as input data. Comparative data measured at reference farms for calibrating the computing parameters are also used as input data in the invention. The harvesting decision may be made by comparing the obtained predictions for different cultivations with each other and/or with a target value.
