Abstract: A negative pressure water supplying and controlling pot device was used to control different soil water contents by setting the water supply tensions（WST）of the devices at different values. Yield and quality of potted cucumber fruit in greenhouse were study under seven WST，i.e.，1，3，5，7，9，11 and 13 kPa. The results showed that yield，WUE and marketable rate of fruit had a parabola change tendency under seven treatments，the maximum yield and marketable rate of fruit value appeared in 3–9 kPa and 3–5 kPa separately，but plant WUE in 3–13 kPa had no differences. There were no significantly differences in water content and specific gravity of fruit among the seven treatments，and also the fruit length，mean fruit weight and total pigment content of peel except 1 kPa，which was significantly lower than other treatments. Tannin content within 3–5 kPa treatments were significantly bigger than 7–13 kPa treatments. Soluble solids and vitamin C content of fruits were significantly lower. Nitrate content of cucumber fruits within 3–7 kPa treatments were significantly lower than 9–13 kPa treatments. The above results indicated that range of 3–7 kPa water supply tension when soil relatively water content within 55%–81% were more suitable for the enhancement of fruit yield and quality in cucumber.

Key words: cucumber, negative pressure water control, yield, quality, WUE