中文摘要：

通过盆栽试验,研究了低水（W1）、中水（W2）、高水（W3）三种土壤水分和不施氮（N1）、低氮（N2）和高氮（N3）三种施氮量对苹果、梨、桃树幼苗的生长、蒸腾耗水量和水分利用效率的影响。结果表明：三种果树苗耗水量有着明显的差异,在W2N1条件下单株耗水量桃树苗最大,在晴天,苹果、梨、桃树日蒸腾量占日总耗水量依次为：22.4%,18%,35.7%,较阴天依次提高了0.5%,8%,22.6%,三种果树苗在晴天夜间的蒸散量依次为：苹果3.26±0.37 g,梨树4.0±1.41 g,桃树4.63±1.8 g左右;在相同的处理下比较三种果树苗蒸腾速率,桃树苗的蒸腾速率相对较大。增施氮肥可以增加果树苗的累积耗水量,提高果树苗水分利用效率。株高、茎粗等生长量的累积幅度上桃树苗最为明显;水分、氮肥对果树干物质的量的影响也都达到了显著水平,干物质量随着土壤含水量、施氮量的增加而增加。在土壤含水量为田间持水量的60%-70%时,既可以保证果树苗正常的生理生长又可以提高水分利用效率。

英文摘要：

With pot experiment,the growth,transpiration rate,water consumption characteristics and water use efficiency（WUE） of three fruit seedlings were investigated under different water and nitrogen fertilizer treatments.The results showed that water consumption are obviously different among three fruit seedlings;the water consumption of peach seedling is the maximum in three fruit seedling under W2N1 combination condition.The daily transpiration of peach,apple and pear account for 22.4%,18% and 35.7% of daily consumption of water in sunny day and it increased by 0.5%,8% and 22.6% than in cloudy day,respectively.The transpiration rate of three fruit seedling during the night of sunny day was 3.26±0.37 g（apple）,4.0±1.41 g（pear） and 4.63±1.8 g（peach）.The transpiration rate of peach seedling is relatively largeer in three seedlings under the same treatment.The accumulation of water consumption and WUE were enhanced with the increase of the amount of nitrogen fertilizer applied.The peach seedling was most obvious on accumulation range of growth,such as height and stem diameter.Effects of water and nitrogen on dry biomass reached a significant level.Dry biomass rose with the increase of water and nitrogen.It not only guaranteed the normal physiological growth but also increased water use efficiency when the water rate was in a range of 60%～70% of the field capacity.