中文摘要：

通过测定苹果树叶片的蒸腾速率的日变化,对蓄水坑灌不同坑深条件下的果树叶片蒸腾能力进行研究。试验选取两棵长势相近且生长良好的苹果树,分别设定坑深60cm和坑深40cm两种处理。结果显示：蓄水坑灌条件下,两种处理的果树叶片蒸腾速率日变化趋势相似,在7月、9月两个月份均呈单峰曲线,在8月呈双峰曲线,在12∶00均出现午休现象;两种处理的叶片水分利用率的日变化趋势也相似,均在7∶00-8∶00达到最高值,随着时间推移逐渐降低。同时发现,坑深60cm的果树叶片在一天中各个时段的蒸腾速率比同时刻坑深40cm的蒸腾速率慢,水分利用率高;果树叶片的蒸腾作用和水分利用率受气温、叶温、光合有效辐射和水汽压等内外综合因子的控制,且气孔导度对果树叶片的蒸腾作用也有一定的影响。研究结果可为蓄水坑灌坑深的合理确定提供依据。

英文摘要：

In this paper, by measuring the diurnal variation of the transpiration rate of the leaves of apple trees, the transpiration ca- pacity of apple trees under the condition of water storage pit irrigation with different pit depth is studied. The test chooses two simi- lar and well-growing trees, and the pit depth is set as 40 cm and 60 cm, respectively. The results show that under the condition of water storage pit irrigation, the apple trees leaf transpiration rate change trend is similar under two treatments. The change trend shows unimodal curve in July and September and bimodal curve in August, and the lunch break phenomenon appears at 12 ： 00. The diurnal variation trend of leaf water use efficiency of the two treatments is similar. It reaches the maximum value at 7 ： 00-8 ： 00, and decreases along with time. It is also found that the transpiration rate of the treatment with pit depth 60 em is slower than that of the treatment with pit depth 40 cm in each period of the day, and the leaf water use efficiency is higher. The leaf transpiration and water use efficiency of apple trees are controlled by air temperature, leaf temperature, photosynthetic available radiation, and vapor pressure etc. and the stomatal conductance of apple tree also has a certain influence on leaf transpiration. The research results can provide reasonable basis for the decision of pit depth of water storage pit irrigation.