2005 Volume 4 Issue 3 Pages 319-322
The effects of ventilation methods on the growth, fruit quality and yield of watermelon in non-perforated low tunnels were examined. The non-perforated low tunnels are usually ventilated by raising and lowering the edges of the plastic cover. In order to save the daily labor needed to ventilate the tunnels, we tested a treatment method that does not require ventilation for approximately 6 weeks after planting until the fruit set stage. During the initial 4 weeks of this period, the edges of the tunnel were buried with soil (buried) and kept closed. During the latter 2 weeks of this period we left one tunnel slightly open. The control was ventilated as usual. The maximal temperature inside the buried tunnel increased to approximately 50°C, but there was no significant difference in the degree of leaf burn. The growth of watermelon plants in the buried-open tunnel excelled slightly, with heavier fruit weight, higher soluble solid content and yield. The bigger difference in day and night temperature of the buried-open tunnel seemed to be one of the factors contributing to this result. This study demonstrated that it is possible to save most of the labor spent ventilating non-perforated low tunnels for watermelon, and 10% of all the working hours can be reduced. Furthermore, it is expected that growth and productivity will improve when the plants are exposed to high temperatures through the use of this method.