摘要:

【目的】研究不同施氮水平对俄矮2号苹果果实生长发育及品质的影响,明确短枝型苹果树对氮的需求和利用特点,为氮肥资源合理利用和果实品质提高提供科学依据.【方法】以8 a树龄的俄矮2号为试验材料,尿素为氮源,设置对照0（CK）、150（T1）、300（T2）和600 kg/hm2（T3）4个处理,分别于4月10日、6月25日和8月25日施入总氮素的50%、30%和20%,测定并分析各处理果实纵横径、单果质量、果实硬度、可溶性固形物、维生素C、可滴定酸、淀粉、糖组分指标和产量.【结果】与对照相比,在花后65 d、80 d、95 d、115 d、130 d和145 d, T2和T3处理显著提高了果实横径,其中,T2处理果实横径较对照分别高出9.1%、9.45%、8.77%、9.97%、9.34%和9.95%;T3处理较对照分别高出11.1%、9.83%、9.33%、8.03%、6.84%和8.04%;各施氮处理果实纵径无显著差异.T1和T2处理均显著提高了果形指数,较对照分别提高2.6%～10.9%和1.4%～10.1%.施氮量为300 kg/hm2时,果实硬度、可溶性固形物、维生素C、可滴定酸和淀粉含量在大部分时期均为最高,与对照差异显著,同时单果质量和产量也达到最高.随着氮素施用量增加,糖含量均高于同期对照,其中果糖和葡萄糖含量在T2处理下达到最高.【结论】施300 kg/hm2的氮肥,相比其他处理,能够显著提高苹果的果实品质.

Abstract:

【Objective】 The study aimed to explore the effect of different levels of nitrogen application on the growth and quality of dwarf apple fruit and to clarify the characteristics of nitrogen demand and utilization for dwarfing apple trees, providing scientific basis for the rational nitrogen application and improvement of fruit quality.【Method】 The cultivar Oregon Spur 2 of eight years old was employed as the materials, with urea as a nitrogen source.Four levels of nitrogen application（i.e.,treatments） were performed as follows: the control（CK） 0 kg/hm~2,150 kg/hm~2（T1）,300 kg/hm~2（T2） and 600 kg/hm~2（T3）.The 50%,30% and 20% of total nitrogen were applied on April 10,June 25 and August 25,respectively.Fruit diameter, fruit shape index, single fruit weight and firmness were measured, and soluble solids, vitamin C,titratable acids, starch content and sugar components of the fruits were determined.【Result】 Compared with the CK,T2 and T3 significantly increased the transverse diameter of fruits at 65,80,95,115,130 and 145 days after anthesis.The fruit transverse diameter of T2 was 9.1%,9.45%,8.77%,9.97%,9.34% and 9.95% higher than that of the CK,respectively; and for T3 treatment, it was 11.1%,9.83%,9.33%,8.03%,6.84% and 8.04% higher than the CK,respectively.There was no significant difference in fruit vertical diameter among treatments.Both T1 and T2 significantly increased fruit-shape index, and it was increased by 2.6%～10.9% and 1.4%～10.1%,respectively, compared with the CK.For the treatment T2（i.e.,300 kg/hm~2 of nitrogen application）,the fruit hardness and the content of soluble solids, vitamin C,titratable acid and starch were the highest among treatment in the most periods, all of which were significantly different from those of the CK;and also, both the single fruit weight and the yield were the highest.With the increase of nitrogen application amount, the soluble sugar content of fruits was higher for the treatments than was for the CK at given period, and both fructose and glucose contents were the highest under T2 treatment.【Conclusion】 It was indicated that nitrogen fertilizer of 300 kg/hm~2 could significantly improve fruit quality of the apple cultivar compared with other treatments.