The objective of this two-year field study was to assess the effects of controlled-nitrogen (N) fertilizers releasing speed and rates on tree morphology, physiology, yield and fruit quality of apricot (Prunus armeniaca cv. Mogador). In this study, four different releasing speed (conventional: < 1 month, controlled-release: 3, 6 and 9 months) and three N rates (56, 75, and 150 kg ha⁻¹ which is equivalent to 75%, 100% and 200% of recommended rates, respectively) were used. Parameters evaluated included: gas exchange (photosynthesis, transpiration, and stomatal conductance), chlorophyll content index, leaf and soil N concentration, fruit yield and quality component [total soluble solids, sugar content, fruit color coordinates (L*, a*, b*), firmness, and radical scavenging activity]. The physiology and fruit quality of apricot trees responses to 6-month controlled-release fertilizer was comparable to the conventional. In both growing seasons (2019–2020), gas exchange, soil and leaf N concentration and fruit quality components from the 6-month controlled-release fertilizer were similar or higher (never lower) than conventional. Interestingly, the 6-month controlled-release fertilizer had higher yield than conventional in 2020. This study revealed that the response of apricot trees to controlled-release N fertilizers was significant after two years of application. Higher N rate (150 kg ha⁻¹) significantly increased fruit yield and reduced sucrose content compared to 75 kg N ha⁻¹ in both years. In 2019, high N rate (150 kg ha⁻¹) reduced fruit redness coordinate (a*) which is considered a visual guide for consumers to select ripen fruits. Overall, this study highlighted the usefulness of using controlled-release fertilizer as an alternative “less waste” N source. The long-term use of controlled-release fertilizers hold promise for increasing apricot production and reducing environmental contamination.

这项为期两年的实地研究的目的是评估受控氮 (N) 肥料的释放速度和速率对杏树 ( Prunus armeniaca cv. Mogador) 的树木形态、生理、产量和果实品质的影响。在这项研究中，四种不同的释放速度（常规：< 1 个月，控释：3、6 和 9 个月）和三种 N 速率（56、75 和 150 kg ha ^-1分别相当于推荐率的 75%、100% 和 200%）。评估的参数包括：气体交换（光合作用、蒸腾作用和气孔导度）、叶绿素含量指数、叶片和土壤 N 浓度、果实产量和品质成分 [总可溶性固体、糖含量、果实颜色坐标（L*、a*、b *)、紧实度和激进的清除活性]。杏树对6个月控释肥的反应生理和果实品质与常规肥料相当。在两个生长季节（2019-2020 年），来自 6 个月控释肥料的气体交换、土壤和叶片 N 浓度以及果实品质成分与常规肥料相似或更高（从未低于）。有趣的是，2020年6个月控释肥的产量高于常规。这项研究表明，杏树在施用两年后对控释氮肥的反应显着。更高的氮含量（150 kg ha^{-1 ) 与两年的 75 kg N ha -1}相比，显着提高了果实产量并降低了蔗糖含量。2019年，高氮含量（150 kg ha ^-1）降低了果实红度坐标（a*），这被认为是消费者选择成熟果实的视觉指南。总体而言，这项研究强调了使用控释肥料作为替代“减少浪费”氮源的有用性。长期使用控释肥料有望增加杏产量并减少环境污染。