EFFECT OF SINGLE- AND DOUBLE-LAYER POLYOLEFIN ON THE MICROCLIMATE OF THERMAL SCREENED GREENHOUSES FOR STRAWBERRY CULTIVATION

Abstract

Strawberry cultivation highly depends on environmental factors. Two gothic greenhouses with different glazing material-thermal screen configurations (single layer (SLGH) and double layer (DLGH)) were used for strawberry cultivation. The research assesses the impact of glazing material-thermal screen configurations on temperature, relative humidity (RH), vapor pressure deficit (VPD), and solar radiation (SR), and the subsequent effect on strawberry yield in both greenhouses. Strawberries were planted on five benches, with 660 stands per greenhouse. Daily environmental parameters were recorded. The mean daytime air temperature, RH, VPD, and SR were 2.5°C ± 15.7°C, 10.7% ± 63.1%, 0.3 ± 0.8 kPa, and 101.8 ± 151.9 Wm−2, respectively, for SLGH, and 2.5°C ± 15.9°C, 10.3% ± 66.1%, 0.3 ± 0.8 kPa, and 111.5 ± 160.9 Wm−2, respectively, for DLGH. However, the mean night air temperature, RH, and VPD were 2.6°C ± 10.2°C, 5.1% ± 86.7%, and 0.1 ± 0.2 kPa, respectively, for SLGH, and 2.7°C ± 10.3°C, 3.0% ± 92.8%, and 0.0 ± 0.1 kPa, respectively, for DLGH. Comparing the SLGH and DLGH, VPD, and SR were significantly different during the day, whereas RH and VPD were significantly different at night (p < 0.01). Tukey’s HSD test further showed that RH, VPD, and SR were significantly different (p < 0.01). The yield in the SLGH was 3.2% greater than that in the DLGH and can be attributed to the higher daytime VPD and a lower RH achieved in SLGH at night. The environmental parameters had significant interaction on yield with a resultant R2 value of 0.89 and 0.79 for SLGH and DLGH, respectively. The study established that the configuration of glazing material and thermal screen influence greenhouse microclimate and strawberry yield.