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[目的]运用投影寻踪回归分析法建立苹果树蒸腾量的预测模型,为更方便更好地预测苹果树蒸腾量提供指导。[方法]根据2009年5～9月气象站观测数据,对气温、相对湿度、风速、太阳辐射、大气压、土壤温度、叶温和水面蒸发量进行分析,并应用投影寻踪回归分析法建立了各气象因子与苹果树蒸腾量的预测模型。[结果]气象数据分析表明,大气水势随着气温增高呈减小的趋势,但随着气温降低和湿度增加而增加。气温、净辐射与作物叶水势均呈抛物线关系。随着净辐射的增大,作物消耗的水量增大,叶水势降低。由叶水势与土壤含水率关系可知,当土壤含水率减少时,苹果根系难以吸收到足够的水分,不能满足叶片蒸腾耗水的需求,导致叶片含水量偏低,叶水势也随着下降。苹果叶水势随着土壤含水率的降低而降低。[结论]运用投影寻踪回归分析法建立了气象因子对苹果树蒸腾量的预测模型,且预测精度较高。
[Objective] The research aimed to establish a prediction model of apple tree transpiration using projection pursuit regression analysis method, which could provide guidance for more convenient and better prediction of apple tree transpiration. [Method] The temperature, relative humidity, wind speed, solar radiation, atmospheric pressure, soil temperature, leaf temperature and water surface evaporation were analyzed based on the observation data from May to September in 2009, and the projection evapotranspiration Prediction Model of Meteorological Factors and Apple Tree Transpiration. [Result] The analysis of meteorological data showed that the atmospheric water potential decreased with the increase of air temperature, but increased with the decrease of air temperature and humidity. Temperature, net radiation and crop leaf water potential showed a parabolic relationship. With the increase of net radiation, the amount of water consumed by crops increases, and the leaf water potential decreases. The relationship between leaf water potential and soil water content shows that when the soil moisture content decreases, it is difficult for apple root system to absorb enough water to meet the demand of leaf transpiration and water consumption, resulting in low leaf water content and leaf water potential declining. Apple leaf water potential decreases with the decrease of soil moisture content. [Conclusion] Projection Pursuit Regression Analysis method was used to establish the forecasting model of meteorological factors on apple tree transpiration and the prediction accuracy was high.