Effects of Drip Irrigation on Growth, Physiological Parameters, and Yield in Hydroponically Cultivated Cucumis sativus

Abstract

The effect of drip irrigation regimen on growth, physiological parameters, and crop yield in Cucumis sativus L. was investigated using a drip irrigation system. The experimental design comprised eight various water regimens (2, 4, 6, 8, 10, 12, 14, and 16 L·h−1). Plants received water five times a day, making a total of 10, 20, 30, 40, 50, 60, 70, and 80 L per day. Growth and photosynthetic parameters were analyzed on a weekly base for a period of 8 weeks. Crop yield was measured at the end of the experiment. In general, photosynthetic rate (A), intercellular CO2 concentration (Ci), stomatal conductance (gS) and the transpiration rate (E) of the cucumber plants were enhanced by increasing water quantities compared with the control. Overall, the total chlorophyll content was significantly enhanced between week 7 and 8 in plants treated with high irrigation volume. Significant improvements were recorded in plant height and number of leave from week 3 to 8 in plants supplied with high irrigation volume. The observed increase in photosynthetic parameters, chlorophyll contents, and plant growths perhaps accounted for the significant increase in the number of marketable fruits in cucumber grown in higher water regimen. The optimal yield of cucumber in the present study was attained in plants irrigated with water regimen ranging from 40 to 80 L per day. The results of this study present valuable information that cucumber growers in South Africa should adopt the use of drip irrigation technique to save water considering the high drought condition in the country.