Abstract: In order to study water use characteristics of apple orchard in the loess gully region of Western Shanxi Province, the sap flow rate of Apple trunk in the main growing season (from April to September) was measured and compared with the environmental factors. The results showed that: (1) the trend of seasonal dynamics of sap flow rate in apple tree trunk was June > May > September > July > August > April. The diurnal variation of sap flow in typical sunny days from April to September showed a single peak curve. The peak values of sap flow rate in April to September were 1496, 1736, 1607, 1537, 1474 and 1674 cm3·cm-2·h-1 in turn. (2) The sap flow rate in the daytime was different from that at night. It showed an obvious circadian rhythm. (3) There was a positive correlation between sap flow rate and solar radiation (PY), net radiation (Rn) and atmospheric water deficit (VPD), and a negative correlation between sap flow rate and relative humidity (RH). The correlation coefficients between sap flow rate and environmental factors PY, Rn, VPD and RH were 0789, 0783, 0619 and -0482, respectively. The present research was of great significance for strengthening the management level of apple orchard and improving the quality and yield of apple.

Key words: apple, sap flow rate, environmental factor, loess gully

摘要： 为研究晋西黄土残塬沟壑区苹果园的水分利用特征，对黄土残塬沟壑区苹果园主要生长季（4—9月）苹果的树干液流速率进行测定，并与环境要素进行对比分析。结果表明:（1）苹果树干液流速率值的季节动态表现为6月 > 5月 > 9月 > 7月 > 8月 >4月，4—9月典型晴天的液流日变化均表现为单峰曲线，液流速率的峰值依次为1496、1736、1607、1537、1474、1674 cm3·cm-2·h-1。（2）液流速率在白天和夜间表现出较大的差别，有较明显的昼夜节律性。（3）苹果树干液流与太阳辐射（PY）、净辐射（Rn）、大气水分亏缺（VPD）均存在正相关关系，与大气相对湿度（RH）存在负相关关系，液流速率与气象因子PY、Rn、VPD、RH的相关系数分别为0789、0783、0619和-0482。研究结果对于加强果园的经营管理水平，提高苹果果品与产量具有重要意义。

关键词: 苹果, 液流速率, 环境因子, 黄土残塬沟壑区