CLIMATIC CHARACTERIZATION OF TWO PLASTIC COVERED GREENHOUSES UNDER DIFFERENT NATURAL VENTILATION METHODS, WITH A COOL SEASON TOMATO CROP

Climatic characterization of non heated greenhouses in Portugal is important in order to understand the effects of different ventilation methods on climatic variables such as air temperature, soil temperature, and some psychrometric characteristics of the air, which can influence fungal disease development, namely Botrytis cinerea.

Following previous experiments with smaller greenhouses with a similar production system, an experiment was carried out to compare two identical plastic covered tomato greenhouses, with different ventilation methods (NCG- night closed greenhouse; NOG-night opened greenhouse). All variables were also measured outside.

Results show that permanent overnight ventilation may induce less favorable conditions to fungal disease development, especially in terms of relative humidity.