矮砧密植苹果光合特性及产量对水分的响应

【目的】 研究灌水量对新疆南疆矮砧密苹果光合特性、产量及水分利用效率的影响。【方法】 以5 a生皇家嘎啦(Royal Gala)为试验树种,常规灌溉果园为对照处理(CK),灌水定额为5.14 mm,共设置5个灌水定额,即W₁(13.5 mm)、W₂(18 mm)、W₃(22.5 mm)、W₄(27 mm)及W₅(31.5 mm),分析苹果光合特性、产量及水分利用效率对水分的响应机制。【结果】 不同灌水量下的苹果净光合速率、气孔导度和蒸腾速率日变化均呈单峰曲线,并在10:00达到峰值,而胞间CO₂浓度变化规律则相反,呈倒“V”型,在10:00时处于最小值。光合指标日均值随着灌水量的增加呈先增后减的趋势,且净光合速率、气孔导度及蒸腾速率均以W₄处理最高,W₃处理次之;与CK相比,W₃处理和W₄处理,叶片瞬时水分利用效率分别提高了5.06%和3.37%;苹果产量则随着灌水量的增加呈先增加后降低的趋势,W₄处理产量最高,但与W₃处理差异不显著,分别较CK增加了17.01%和14.94%,且灌溉水利用效率较CK分别提高7.23%和26.33%。【结论】 新疆南疆矮砧密植5 a生皇家嘎啦苹果灌溉定额为472.5 mm,灌水次数21次时,苹果产量较高,较常规灌溉果园节约灌水9.06%的灌溉。

Photosynthetic Characteristics and Yield Response to Water Content of Apple under Close Planting on Dwarf Rootstocks in Southern Xinjiang

【Objective】 To explore the influence of irrigation amount on the photosynthetic characteristics, yield and water use efficiency of southern Xinjiang short-stock dense apple.【Method】 5-year-old Royal Gala was taken as the test tree species, conventional irrigation orchard as the control treatment (CK), and the irrigation quota was 5.14 mm, a total of 5 irrigation quotas were set, namely W₁ (13.5 mm), W₂ (18 mm), W₃ (22.5 mm), W₄ (27 mm) and W₅ (31.5 mm) to analyze the response mechanism of apple photosynthetic characteristics, yield and water use efficiency to water.【Result】 The daily changes of net photosynthetic rate, stomatal conductance and transpiration rate of apples under different irrigation amounts all showed a single-peak curve, and reached the peak at 10:00, while the intercellular CO₂ concentration changed in the opposite way, showing an inverted "V" type, at the minimum at 10:00.At the same time, the daily average value of photosynthetic index showed a trend of first increasing and then decreasing with the increase of irrigation amount.The net photosynthetic rate, stomatal conductance, and transpiration rate were all the highest in W₄ treatment, followed by W₃ treatment.Compared with CK, W₃ treatment, and W₄ treatment, the leaf instantaneous water use efficiency increased by 5.06% and 3.37% respectively; the apple yield increased first and then decreased with the increase of irrigation amount, W₄ treatment had the highest yield, but it was not significantly different from W₃ treatment, increased by 17.01% and 14.94%, respectively compared with CK, and the irrigation water use efficiency increased by 7.23% and 26.33% respectively compared with CK.【Conclusion】 Therefore, considering the photosynthetic characteristics, yield and water use efficiency of apples, the irrigation quota is 472.5 mm and the irrigation frequency is 21 times, the yield of apples is higher, which can save 9.06% of irrigation water compared with conventional irrigation orchards, so it can be used as an irrigation guidance scheme for 5a Royal Gala apples in southern Xinjiang.