Abstract Computer simulation is one of the most effective methods in the analysis and estimation of agricultural crop production. However, very little is known about the growth mechanism of the plants above the level of physiological processes. The unknown mechanisms are substituted by statistical models and experimental data. This fact raises the question of portability of the models to an environment different from the one used for identification. Many analysts formulate heuristic principles and build models on them. A relatively simple adaptation principle which can be used effectively in building crop growth models and carry out simulation experiments is presented.