THE EFFECT OF SCREENHOUSE HEIGHT ON AIR TEMPERATURE
The use of screenhouses in protected cultivation is nowadays a common prac-tice in many countries. When fine mesh screens are used in the screenhouse construc-tion, the resistance of the screens to airflow is high and ventilation rate is strongly reduced in comparison to the open field. Thus, growers tend to move to higher screenhouses since they assume that in such structures accumulation of warm and humid air near the plants is diminished. The goal of this research was to investigate, in insect-proof screenhouses, the effect of screenhouse height on air temperature. Experiments were conducted in two flat top screenhouses each of an area of 745 m2; one with a roof height of 4 m (LSH) and the other with a roof height of 6 m (HSH) with 16 m of separation between them. The houses were covered with a 50-mesh screen which is commonly used with tomato cultivation in Israel. The daily courses of air temperature were very similar in the two houses. The average air temperature in the HSH was nearly at all times higher than in the LSH. The largest differences in temperature between the houses, of about 1C, were observed during day; slightly lower differences were observed during night. The most significant difference between the two houses was related to the vertical gradients of temperature. The results show that the microclimate in the vertical direction appears to be more homogenous in the HSH than in the LSH.
Teitel, M., Garcia-Teruel, M., Alon, H., Gantz, S., Tanny, J., Esquira, I., Sofer, M., Levi, A., Schwartz, A. and Antler, A. (2014). THE EFFECT OF SCREENHOUSE HEIGHT ON AIR TEMPERATURE. Acta Hortic. 1037, 517-523
insect-proof screen, microclimate, temperature distribution