ISHS Acta Horticulturae 801: International Symposium on High Technology for Greenhouse System Management: Greensys2007
GREENHOUSE COOLING STRATEGIES FOR MEDITERRANEAN CLIMATE AREAS |
| Authors: | J.C. Gázquez, J.C. López, J.J. Pérez-Parra, E.J. Baeza, M. Saéz, A. Parra |
| Keywords: | climate, forced ventilation, whitening, evaporative cooling, fog system |
| DOI: | 10.17660/ActaHortic.2008.801.45 |
| Abstract:
A common trend in the markets nowadays is to consume high quality fresh fruit and vegetables all year round, thus forcing to grow with these quality standards during the summer as well. Controlling the greenhouse climate during this season is a problem of increasing importance in Mediterranean climate areas, such as Spanish south east. A good management of the climate control equipment (ventilation, evaporative cooling and shading), could attenuate crop physiological stress situations, thus having a positive effect on the final yield and the product quality. During two years, different cooling strategies (white washing, fogging and natural and forced ventilation) and its effects on the microclimate, growth and yield of a substrate grown sweet pepper crop were evaluated in three multi-tunnel experimental greenhouses. Fogging was the most efficient method in controlling the maximum temperature and VPD values but was the least efficient in controlling canopy temperature. Neither fogging nor forced ventilation improved the total and marketable yield in relation to white washing, despite the radiation reduction. The crop subjected to the fog system showed the highest incidence of blossom end rot (B.E.R.). An economic evaluation showed that whitening was the most profitable cooling treatment. Thus, we can consider that combination of whitening of the plastic cover and natural ventilation as the most efficient cooling system in terms of water and energy use. | |
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