COMBINATION OF GROWTH MODELS FOR OPTIMIZED CO2 - AND TEMPERATURE-CONTROL OF LETTUCE
The model SAREL for lettuce growth was developed, dividing growth into 4 phases with a description of the response surface for each phase. This model is very simple and results in predictions of high stability but shortest time step is one day. In contrast, short-term prediction with the model SASIM is physiological reasonable but long-term stability seems to be lacking.
Simulation runs with each model show averaged effects of CO2 with SAREL and an important increase of growth rates with SASIM especially under high light conditions. With experimental data from earlier treatments and from a new experiment, a research project was started to find out wether a combination of the two growth models will result in higher returns. So far only preliminary results were obtained, showing slightly higher growth rates when CO2 and temperature are controlled on an hourly basis.