Effects of Foliar Treatment and Water Scarcity on Pomological and Biochemical Characteristics of Orange Cultivars During Post-harvest Management

This study investigated the impact of pre-harvest practices and post-harvest procedures on fruit quantity and quality in two orange varieties (‘Valencia’ and ‘Thompson Navel’) stored under traditional (TP) and modified atmosphere packaging (MAP) conditions. Conducted in the Sari region of Iran over 2 years (2021–2022), pre-harvest treatments included water deficit at two levels and foliar spraying of chitosan and melatonin. Post-harvest treatments involved different packaging methods and storage durations. Pomological attributes such as fruit weight and volume were significantly influenced by storage conditions and treatments, with MAP enhancing these attributes while water deficit decreased them. The combined application of chitosan and melatonin increased fruit volume by 40.46% in ‘Valencia’ and 32.29% in ‘Thomson Navel’ compared to control treatments. Biochemical characteristics like vitamin C content, total soluble solids, and tissue firmness decreased during storage but were higher with MAP and lower with water deficit. Total phenolic content rose with storage duration, especially with chitosan and melatonin treatments. Flavonoid compound content varied with storage conditions and treatments. Notably, MAP reduced the content of particular compounds compared to TP. Integrated treatments involving chitosan and melatonin positively affected fruit quality and biochemical properties during storage, suggesting their potential for enhancing post-harvest quality in oranges.