Relationship Between Stem Flow Rate and Meteorological Factors in Different Growth Periods of Mature Grey Jujube

【Objective】 Under the condition of micro sprinkler irrigation, the stem flow rate of mature jujube under different weather and different meteorological factors was studied, and the water consumption of mature jujube was accurately measured, which provided practical guidance for optimizing soil water management of jujube. 【Methods】 The stem flow rate of jujube was continuously monitored by the needle type stem flow meter, and the influence degree of different weather and meteorological factors on the stem flow rate of jujube was analyzed. 【Results】 The fluctuating process of stem flow rate in sunny and cloudy days presented an inverted "U" shaped single peak curve, while in cloudy days it presented an "M" shaped double peak curve. The cumulative trend of stem flow of jujube in a day was "S" change, and the order of water consumption in each growth period was: fruit enlargement >fruit maturity > flowering > Leaf bud stage. The correlation between stem flow rate and air temperature is the highest in mature period, and the rest is solar radiation. The correlation coefficients R_D1= 0.964^**, R_D2 =0.969^**, R_D3= 0.957^** and R_D4=0.886^** between solar radiation and stem flow rate of jujube in different growth period. Using multiple linear regression to input regression of stem flow rate and meteorological factors in different growth period of jujube, a multiple linear regression model of stem flow rate and meteorological factors in different growth period of jujube was established under different weather conditions. Through the test of regression coefficient and correlation coefficient, the multiple linear regression equation in each growth period reached a significant level. 【Conclusion】 In different growth period, the order of stem flow rate in typical weather is sunny > cloudy > dark. The key period of water demand in the whole growth period is fruit enlargement period. Solar radiation and air temperature are the most important meteorological factors that affect the stem flow rate of jujube.