Nitrogen fertilization of stone fruits: a comprehensive review

Stone fruits, including peaches, plums, cherries, apricots, and almonds, are economically significant crops that require careful nitrogen management to optimize growth, yield, and fruit quality. Nitrogen (N) is a crucial macronutrient for stone fruits, playing a vital role in leaf development, photosynthetic capacity, and in the formation of sugars and carbohydrates essential for fruit development. However, nitrogen application needs careful management, as both deficiency and excess of this nutrient element can adversely affect fruit size, quality, and yield. Excessive nitrogen can lead to decreased flesh firmness, reduced sweetness, and increased susceptibility to diseases. Additionally, nitrogen remobilization from senescing leaves to storage tissues is a key process that supports nutrient use efficiency and reduces reliance on external nitrogen inputs in deciduous fruit crops. The timing of nitrogen application is critical, with peak demand occurring during bud break, flowering, and fruit set. Among its method of application, fertigation has proven to be an effective method for delivering nitrogen, improving leaf nutrient status, vegetative growth, and fruit quality. The interaction between nitrogen fertilization and soil organic matter (SOM) is also significant, as nitrogen influences SOM dynamics and potentially enhance the soil fertility and structure. This comprehensive review consolidates current knowledge on nitrogen fertilization in stone fruits, emphasizing the importance of balanced nitrogen management to achieve optimal growth, yield, and fruit quality. Despite extensive research globally, there is need to tailor nitrogen management practices to local conditions and improve sustainable stone fruit production.