EVALUATING THE PERFORMANCE OF THE GREENHOUSE AS AFFECTED BY SHADOW PAINTING MATERIAL

Abstract

Indoor experiments and field study were conducted at the Dept. of Agric. & Bio Systems Eng., Faculty of Agriculture, Menoufia University. The indoor experiments concerned with the effect of using shading materials on the performance inside the greenhouse. With each shading material, the atmospheric parameters inside the greenhouse were measured. These parameters were: average air temperature, internal and external radiation. The tested shading materials were: red oxides, Yellow oxides, Ammonium chloride, sodium sulphate and white plastic. The main objective of field experiments was to drive both of cucumber yield and water use efficiency grown under two greenhouses. First was covered by painted plastic with white plastic and the second was covered by an unpainted ordinary plastic. The field experiment was carried out under four levels of water application rate which were: 100%, 90%, 80% and 70% of potential evapotranspiration ETo. The irrigation water was applied by a drip irrigation system which constructed inside each greenhouse. The painted cover with white plastic achieved the lowest radiation transmission coefficient (0.44) and also achieved the highest cucumber yield (15.5 Mg/Fed) at 80% of potential evapotranspiration. It also achieved the highest value of water use efficiency which was 10.23 kg/m3 at the same level of water application rate.