COMBINATION OF GROWTH MODELS FOR OPTIMIZED CO₂ – AND TEMPERATURE-CONTROL OF LETTUCE

For optimization of greenhouse climate control growth models are needed to predict reaction of plants to growth factors.
Further information about the appropriate temperature- and CO₂ -control time step is required.

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.

International Workshop on Greenhouse Crop Models

H. Liebig, G. Alscher

https://doi.org/10.17660/ActaHortic.1993.328.13