不同灌水量条件下苹果树茎流变化规律及其影响因素

Sap flow change rules of apple tree under different irrigation amounts and its influencing factors

为分析阿克苏地区苹果树在不同灌水量条件下(滴灌单次灌水量99.0、148.5、198 m^(3)·hm^(-2),分别标记为W1、W2、W3)茎流变化规律和气象因子对其的影响,以红肉苹果树(红色之爱119/06)为试验材料,2020年6—9月通过TDP插针式茎流仪连续观测苹果树茎流速率,用HOBO小型气象站自动获取气象数据。结果表明,不同灌水量条件下苹果树茎流速率均呈昼高夜低的变化趋势,夜间茎流速率变化平稳。苹果树日均茎流速率排序为W3>W2>W1。瞬时间尺度下大气温度、太阳辐射和饱和水汽压差是影响茎流速率的关键影响因子,日尺度下50 cm土壤体积含水量对茎流速率影响显著。适当减少灌水量有利于提高灌溉水分生产率,增加总糖和维生素C含量,降低总酸含量。W2处理的灌水量更适合研究区苹果树灌溉。7、8月份苹果树茎流速率较高,该时期蒸腾耗水较高,应及时补充灌水,选择日出前或日落后灌水效果最佳。

To analyeze the sap flow change rules of apple trees under different irrigations amounts(single irrigation quota 99.0,148.5 and 198 m^(3)·hm^(-2),which were respectively marked as W1,W2 and W3)and the influence of meteorological factors on it in Aksu area,red apple trees(red love 119/06)was used as materials,sap flow rate of the apple trees were continuously observed by TDP contact-pin sap flow meter from June to September in 2020,and HOBO small meteorological station was used to automatically acquire the meteorological data.The results showed that the sap flow rate of apple trees under different irrigation amounts present a variation trend that were higher at daytime and lower at night,and the changes of sap flow rate at night were stable.The order of average daily sap flow rate of apple tress was W3>W2>W1.Air temperature,solar radiation and vapor pressure defict difference were the key factors affecting sap flow rate on the instantaneous time scale,50 cm soil volumetric moisture content had a significant effect on sap flow rate at daily scale.Proper reduction of irrigation water was beneficial for the improvement of irrigation water productivity,increasing the total content of sugar and vitamin C,as well as reducing the total acid content.The irrigation amount disposed by W2 was more suitable for the irrigation of apple trees in the research area.The sap flow rate of apple trees was higher in July and August,the transpiration water consumption was high in this period,irrigation should be carried out timely,and the best irrigation should be before sunrise or after sunset.