黄土塬区苹果树蒸腾速率变化特征及其影响因子

The characteristics of apple tree transpiration rate and its influencing factors on the loess tableland region

报道了应用茎流计（TDP）测定黄土塬区苹果树主要生长季节蒸腾速率的试验结果,并对其影响因子做了分析。研究表明：晴天苹果树蒸腾速率的日变化为单峰曲线;逐日变化为昼高夜低、骤升骤降的特征,夜间接近于0,白天单株苹果树蒸腾速率峰值变化幅度为300-1 000 g/h;6-8月是苹果树蒸腾耗水的主要月份,其中7月份的单株平均日蒸腾量为3 038 g/d;与苹果树的生育期相联系,平均日蒸腾量最大出现在果实膨大期,随后是秋梢生长期和幼果膨大期。在测定时段,随总辐射的增强及气温的升高,苹果树蒸腾速率随之增加。

This paper reported the experimental results of apple tree transpiration rate measured by TDP mainly in the growing seasons on the Loess Plateau,and the influencing factors to transpiration rate was also analyzed.The results showed that： the change of transpiration rate in clear day was in a form of single-peak curve;the diurnal change of transpiration rate was characterized by an upsurge and followed by a plummet.The transpiration rate,at night,was near 0 g/h,while it changed from 300 g/h to 1 000 g/h in the day time.June,July and August were the main periods for transpiration water consumption.In July,the amounts of daily transpiration reached to 3 038 g/d.Associated with the growth phase of apple trees,the maximum daily transpiration amounts appeared in the fruit expanding process stage,then the growing stages of shoots and young fruit in the autumn.In the experimental period,the transpiration rate of apple trees increased with the increasing of global solar radiation and atmospheric temperature.