Effects of dripper discharge and spacing on growth of cucumber in Chinese solar greenhouse under drip irrigation

Dripper discharge and spacing are two of the most important parameters of drip irrigation system designing. In order to investigate the investment of irrigation system, experiments were conducted to test the effects of dripper discharge and spacing on the growth of cucumber in solar greenhouse. Four treatments were designed and the dripper discharges (dripper spacing) were 2.7 L/h(30 cm), 2.7 L/h(50 cm), 1.4 L/h(30 cm) and 1.4 L/h(50 cm), respectively. The same irrigation amount was delivered in four treatments. The result showed that yields of four treatments were 80.63, 85.66, 94.31 and 90.91 t/hm² and water use efficiencies were 23.6, 24.9, 27.9 and 25.4 kg/m³, respectively. There was no significant statistical difference. It implied that for cucumber with ridges in greenhouse, the bigger dripper spacing and less discharge can be used in drip irrigation, plant yield and quality cannot be affected but the investment of irrigation system can be reduced. The evapotranspiration, crop coefficients and water requirement coefficients of cucumber under drip irrigation were also estimated in this paper.