Effect of Stable Negative Pressure Irrigation on the Growth and Development of Eggplant (Solanum melongena)

This study was conducted with an objective to determine the optimal negative pressure irrigation suitable for growth and development of eggplant. The total water consumption, yield, growth and development, physiological activity, and quality of eggplant were tested using a pot experiment in a greenhouse with four treatments, namely -3, -8, -15 kPa and normal irrigation (C). The negative pressure was maintained using a stable negative pressure irrigation device. The total water consumption of eggplant was decreased by 20.51–70.00%, the total water consumption intensity was decreased by 22.18–70.27%, and the water use efficiency was increased by up to 7.45–41.48% under negative pressure irrigation compared with control (C). When the irrigation pressure was controlled at -3 kPa, the nitrate reductase activity, root activity, and chlorophyll content were increased by 6.14–15.5%, 11.11–33.33% and 20.04–51.58%, respectively. The yield of eggplant was also increased by 12.43% compared with control. The soluble sugars, soluble protein, and vitamin C contents of eggplant fruits at different maturation stages were increased by 14.47–47.22%, 16.33–58.78%, and 19.64–43.42% at -3 kPa, respectively, compared with the control. Taken together, it was observed that stable negative pressure irrigation in the range of -3 to -15 kPa obviously reduced water consumption of eggplant, and had a water saving effect. Negative pressure irrigation (-3 kPa) improved the water use efficiency, physiological activity, growth and development, and yield and quality of eggplant. © 2021 Friends Science Publishers