Effects of Cardboard Box Ventilation Hole Size During Forced-Air Precooling on Postharvest Quality and Physiological Properties in Cut Roses

Forced-air cooling (FAC) is a method for rapidly reducing the temperature of horticultural products. However, its effects on the physiological properties and quality of cut flowers remain elusively unclear. This study investigated the impact of FAC with different vent hole diameters (4, 8, and 12 cm) on multiple metabolic pathways and the quality of cut rose flowers. Compared with controls with a conventional slow cooling method, FAC using 8 cm vent holes (FAC8) prolonged the vase life of cut roses by 3 days and reduced Botrytis cinerea incidence by 60%. The data revealed that FAC8 suppressed excessive transpiration in the late vase stages while it enhanced water uptake throughout the vase period. Additionally, FAC8 reduced the respiratory rate in cut roses, decreasing cumulative respiration by 15% versus controls. When detached leaves from cut roses were subjected to water loss treatment, FAC8 induced tighter stomatal closure, resulting in a 33% smaller stomatal aperture than that of controls after 2 h. Correlation analysis of measured indices demonstrated that FAC significantly contributed to the improvement of postharvest quality (p < 0.05) via the regulation of physiological properties. In conclusion, FAC enhances the postharvest quality of cut roses by maintaining stomatal regulatory ability.