The effects of preharvest shading and postharvest storage temperatures on the quality of ‘Ponkan’ (Citrus reticulata Blanco) mandarin fruits

• Late shading treatment could improve tree water status resulting in higher fruit juice content.
• White shading nets can significantly reduce the incidence of sunscald and granulation in Ponkan fruits.
• Preharvest shading application in Ponkan orchards does not affect postharvest fruits storage quality.

A two-year trial was performed to investigate the effects of using preharvest white shade nets and postharvest storage at 13.5 °C or 25 °C on the physiological responses and quality of ‘Ponkan’ mandarin fruits. A significant reduction in leaf and fruit surface temperatures, PPF, and sunburn was seen when using white shade nets in comparison with the control sample. Trees grown under white netting had a significantly higher juice percentage, less weight loss, lower granulation percentage, and lower percentage decay than the control sample. However, there were no significant differences in peel color, total soluble solids (TSS), and titratable acid (TA) between the control and shading samples after postharvest storage at 13.5 °C or 25 °C. In summary, ‘Ponkan’ mandarin grown with white shading nets exhibited greater sunscald resistance, higher juice percentage, and less weight loss and granulation when stored at 13.5 °C postharvest than the mandarin grown without shading and those stored at 25 °C.