Effects of small tube flow deficit irrigation on yield and quality of greenhouse grape under delayed cultivation

Effects of deficit irrigation with small tube flow on water consumption, yield, water use efficiency, appearance quality and nutrition quality of delayed grapevine were tested in Zhangye Irrigation Experiment Station. The results showed that grapes' water consumption coefficient accounted more than 50% in fruit enlargement period, and grape yield reduced 32.53% under deficit irrigation in this phase. Insufficient water supply in the coloring and mature period could increase the total sugar content of grape and reduced titratable acid content, that was to say improved grapes' comprehensive nutritional quality. Fruit enlargement period plays an important role on grape quality formation. Under insufficient water supply condition in this period, the single fruit weight, anthocyanin content decreased, and grape sour degree aggravated. This research suggests that sensitivity of grapes' yield and quality with insufficient irrigation in different growth period are different, and it is important to study it for achieving water-saving and improving grapes' quality.