The influence of sucrose,ethanol and calcium nitrate on the freezing-point and long-term low-temperature storage of carnation flowers

Both tight bud and open carnation (Dianthus caryophyllus L.) flowers survived ?4°C for 5 days without injury if flowers were pulsed with 20% sucrose at 25°C for 24 hours prior to storage. Between the 8th and 10th day of storage, both stem and floral tissue froze. Flowers pulsed with 10 or 20% ethanol for 24 hours at 25°C survived ?2°C for 5 days, while those pulsed in water failed to open normally or were frozen when stored at 0°C for 5 days. Flowers stressed (wilted) for 24 hours at 25°C survived for only 5 days at ?4°C. After pulsing, tight buds were more resistant to freezing than open flowers and stem tissue was more resistant than petal tissue. However, during storage stem tissue froze before petal tissue. Using exotherm analysis, petal tissue froze at ?2.3 or ?4.7°C when first pulsed with water or sucrose and at ?3.0 and ?3.8°C after 7 days.