Effects of Malic Acid Vase Solution on the Postharvest Quality and Vase Life of Cut Rose ‘Candlelight’ Grown Under Low-Light Conditions

Low-light conditions during winter cultivation reduce the postharvest quality of cut roses, highlighting the importance of effective postharvest management. This study investigated the effects of malic acid (MA) and sucrose (Su) vase solutions on the postharvest quality and vase life of cut rose (Rosa hybrida L.) ‘Candlelight’ grown under low-light conditions. Cut flowers were maintained in distilled water (DW), tap water (TW), 1% chrysal (CR), 50 mg·L−1 malic acid (MA), 1% sucrose (Su), or 50 mg·L−1 malic acid + 1% sucrose (MA + Su). MA resulted in the longest vase life, extending it by 22–29% compared with DW and TW, although a significant difference was observed only between MA and DW. It also maintained relatively high vase solution uptake and RFW and prevented basal stem browning. In contrast, Su reduced vase life by 40–43% compared with DW and TW despite increasing leaf carbohydrate content, whereas MA + Su resulted in a significantly shorter vase life than MA alone. Correlation analysis revealed that vase life was positively associated with RFW and flower diameter and negatively associated with non-photochemical quenching (NPQ), fluorescence decline ratio (Rfd), and the petal color parameters L* and C*. These findings suggest that MA treatment sustained vase solution uptake and relative fresh weight, thereby contributing to the maintenance of postharvest quality and prolonged vase life.