Effect of improved natural ventilation of plastic house on cucumber in Egypt

摘要

The experiments were conducted in El-Bosaily Protected Cultivation greenhouses during 1998 and 1999 seasons in order to study some possibility for improving natural ventilation of existing single arch plastic houses. Cucumber (Cucumis sativus, L.) cv. Primo F_1, seedlings were transplanted during February of both seasons in the plastic house. Two methods of natural ventilation were tested in comparison with standard plastic house that contains ventilation opening in the overlap area, each 5m longitudinally. The first method was side ventilation of 1m width along both sides of the plastic house (120 m~2 opening/510 m~2 cultivation area) and the second method was a longitudinal top ventilation of about 0.8 m (48 m~2 opening/510 m~2/cultivation area). The results show that side ventilation reduced in-house air temperature about 2-3 deg in winter and about 4-5 deg in summer compared to control. Relative humidity was also lower in side ventilation treatment followed by top ventilation then the control. Plant height, number of leaves, number of flowers, number of fruits and total leaf area were increased by using side ventilation. These were reflected positively on the early and total yield where the highest early and total yield were obtained by using side ventilation followed by top ventilation comparing with control.