A SIMPLE KALANCHOË PHOTOSYNTHESIS MODEL FOR GREENHOUSE CLIMATE CONTROL

Crop specific models for plant growth and -development and their sub-models as e.g. microclimate or photosynthesis are needed for decision support systems (DSS) and model based climate control. As most cultivated greenhouse horticultural production crops metabolise using the C3 pathway, most attention in model was put on model development of those crop types. For greenhouse crops with CAM metabolism, however, only little work was done. For the CAM plant Kalanchoë blossfeldiana, only development and quality models were therefore developed. Since Kalanchoë blossfeldiana is changing from C3 in young plants to CAM in older plants, for decisions on climate control actions (manually or automatic) photosynthesis based growth and development models of both C3 and CAM (as well as for all the intermediate stages) are needed. In the present paper a first version of a model describing the different stages of photosynthesis as growth parameter in Kalanchoë was developed for the cultivar ‘Jackie’. The model was calibrated and validated on independent datasets of measurements of leaf photosynthesis. Intermediate stages were modelled by using the C3 and the CAM photosynthesis model.