Micrometeorological characterisation in a screenhouse
2003
Moller, M. | Tanny, J. | Cohen, S. | Teitel, M.
In recent years insect-exclusion screenhouses have become popular among growers because they reduce the need for pesticide application, cost much less than greenhouses and are believed to have a minor effect on the microclimate of the crop. Although the total area of screenhouses around the world is steadily increasing, there is very little data on the microclimate in such structures. The present study is focused on measurements of temperature and humidity profiles, radiation and wind speed in and around a 50-mesh commercial screenhouse for pepper cultivation. We investigated the relationship between the diurnal courses of internal temperature and humidity, their vertical gradients and ambient conditions. It was revealed that the upper region of the screenhouse interacts strongly with the outside. Radiation measurements showed that radiation load under the screen was reduced to almost half of its external value. The results of the wind measurements made with a 3D sonic anemometer indicate that the wind speed at the upper region of the screenhouse, between the top of the plants and the roof, is about 25% of the ambient. An internal counter-flow opposite to the external northwestern wind was observed along the western half of the screenhouse.
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