A Comparison Between Modified-umbrella and High-wire Trellising Systems in a Low-profile Greenhouse for Hydroponic Beit Alpha Cucumber

Abstract

The production of Beit Alpha cucumber (Cucumis sativus) in hydroponic systems has increased in popularity since the early 2000s, along with the use of high-wire trellising systems. Some farmers claim the high-wire trellising systems, also known as drop-and-lean trellising, result in a more consistent weekly yield than umbrella or modified-umbrella systems. This study compared the high-wire and modified-umbrella trellising systems both using a 7 ft top wire and 4 plants/m2 plant density. The fruit weight and number of fruit per plant were significantly greater using the modified-umbrella trellising system, with the number of fruit being about twice as high as the high-wire trellising system. Consistency of yields was also measured for both systems and found to peak at ∼5 to 7 weeks after the start of harvest using both trellising systems. However, peak yields using the modified-umbrella trellising system followed a quadratic curve, implying that the high-wire trellising system results in more consistent yields. Differences in yield and harvest consistency were likely related to light penetration of the plant canopy. Growers using low-profile greenhouses can expect lower yields and more consistent harvests using the high-wire trellising system. Yields may be improved using a higher plant density. Alternatively, succession planting on a 5- to 7-week interval can improve harvest consistency using a modified-umbrella trellising system.