Effects of Irrigation Methods on Transpiration and Water Use Efficiency of Greenhouse Tomato

Abstract

【Objective】In order to explore the effect of high frequency drip irrigation on physiological water saving of greenhouse tomato.【Method】Pot experiment was conducted to study the effects and mechanism of conventional flooding irrigation (CFI) and high-frequency drip irrigation (HDI) on transpiration and water use efficiency of greenhouse tomato. The biomass, leaf area, stomatal conductance, transpiration rate, leaf δ13C , transpiration, water use efficiency were measured and calculated. 【Result】① In the whole growth period, the irrigation times of HDI was 44 times, which was 3.4 times higher than that of CFI, and the irrigation amount was only 71.0% of that of CFI, but there was no significant difference in fruit, stem and leaf dry weight between the two treatments. ② The average transpiration of tomato under HDI was 28.95 L/plant, which was significantly (p>0.05) lower than that under CFI by 24.6%. ③ The irrigation water use efficiency (biomass/irrigation) and water physiological use efficiency (biomass/transpiration) of HDI were significantly (p<0.05) higher than those of CFI by 21.2% and 14.2%, respectively. ④ Compared with CFI, HDI significantly (p<0.05) reduced tomato leaf area, stomatal conductance and transpiration rate by 32.6%, 69.8% and 54.3%, respectively, and significantly increased δ13C value【. Conclusion】 HDI can not only reduce irrigation volume and improve irrigation water use efficiency, but also make the plant in a certain state of water deficit. By reducing leaf area, stomatal conductance and transpiration rate, it can significantly reduce transpiration water consumption, improve tomato water physiological utilization efficiency and realize physiological water saving.