Nitrogen management in enhancing raspberry (Rubus idaeus L.) productivity and sustainable development in fruit cultivation

This study investigated the effect of reduced nitrogen (N) fertilizer dosage on the vegetative and generative potential, physical and chemical characteristics, and fruit yield of raspberry (Rubus idaeus L.). Two raspberry cultivars (Willamette and Meeker) were treated with low and high doses of calcium ammonium nitrate and urea over 3 consecutive years (2021–2023) in Western Serbia. Basic floricane traits and fruit quality parameters were analyzed using widely accepted methodologies. The results showed significant variations in primocane growth, floricane traits, and berry quality in response to different N fertilizer doses, whereas soluble solid content (SSC) was more stable. Lower N fertilizer doses significantly improved primocane properties, productivity, berry weight and dimensions, elongation index, titratable acidity, pH of fruit juice, sugar content, total phenols, and anthocyanins. Environmental conditions in 2021 primarily enhanced productivity and physical fruit properties, while in 2022, they improved the chemical properties of the fruit. In 2023, conditions positively influenced primocane characteristics. This research provides valuable insights into the physiological responses of raspberries to reduced N fertilizer doses, providing a sustainable approach to enhancing both the nutritional value of the fruit and the overall efficiency of raspberry production.