Development, validation and use of a dynamic model for simulate the climate conditions in a large scale greenhouse equipped with insect-proof nets

Easily simulating inside climate conditions in the large insect screened Canary type greenhouses used intensively along the Moroccan coast is particularly important in enhancing this production system. We have therefore developed a global greenhouse climate model based on combined sensible and latent heat balances in which the ventilation flux has been simulated combining buoyancy forces and wind effect. In the region of Agadir in South Morocco, a big commercial greenhouse, farming tomatoes and equipped with insect-proof nets provided the measurements which validated this model. The precise estimation of sensible and latent heat fluxes exchanged among the different components of the green- house balanced the energy and the mass in the system so that inside air temperature and water vapour content were deduced accurately. A study on the effects of various types of insect-proof nets was carried out later to analyse the impact on the climate of varying the net mesh size in the greenhouse. It was shown that with an unchanged open vent surface, the use of an anti-Thrips net was incompatible most of time with a satisfactory climate for plant growth in the coastal areas of southern Morocco