Development of a bio-physical simulator for Mediterranean greenhouses

The aim of this work was the development and validation of a biophysical model (BioSiGreT) by coupling a crop growth model and a greenhouse climate model. The crop growth model is a modification of TOMGRO to simulate 'topping', a short term cropping technique, current practice in Mediterranean greenhouses. The climate model consists of five sub-simulators: the air, crop, cover and soil greenhouse energy balances, as well as the mass balance of greenhouse air. Using outside climate data and the above sub-models greenhouse air temperature and relative humidity, and the temperatures of the cover, the crop and soil can be calculated. Experiments were carried out in the experimental farm of the University of Thessaly near Volos in the continental part of eastern Greece, during the autumn and winter periods of 2005. Crop growth and development, biomass production and greenhouse interior and exterior climate variables were recorded. A good agreement was observed between the measured and simulated values of plant development characteristics and the biomass and fruit production, during the validation process. Simultaneously, a satisfactory agreement was observed between the measured and simulated values of air, cover, crop and soil temperatures. The model was proven to be a valuable tool for greenhouse microclimate and crop growth simulation and could be used to help growers in managing the greenhouse microclimate. The simulator will be further used for greenhouse climate optimization studies