Improving the Scent of Cut Carnation Flowers by Sucrose Treatment Combined with Wet Transport

The scent of cut carnation flowers decreases rapidly after harvest. Recent research has shown that continuous treatment with 5% sucrose mitigates this decrease in the scent of Dianthus caryophyllus ‘Milky Way’. However, continuous sucrose treatment is not practical for actual shipping and transport. It is also unclear how the effect of sucrose treatment on scent is affected by preservatives commonly applied to cut carnation flowers. In this study, the effects of sucrose treatment duration and co-treatment with preservatives on scent emission from cut flowers were evaluated. Sucrose treatment for 24 or 48 h increased scent emission from cut flowers of the ‘Milky Way’ cultivar, and the longer the treatment, the longer the period of high scent emissions. Short-term sucrose treatment promoted scent increases immediately after flower opening, but not later in the anthesis period. These findings suggest that exogenous sucrose is used as a substrate for scent production and is depleted over a short period. To evaluate whether this knowledge could be applied to improve the scent of cut carnations in Japan, we conducted a demonstration experiment wherein cut flowers were treated with 5% sucrose for a 48 h period that included time spent under wet-transport conditions. Thereafter, scent-retention capacity was assessed. Sucrose treatment increased scent emission significantly in all five cultivars tested. Furthermore, in a sensory evaluation test, sucrose treatment increased the percentage of positive ratings for the intensity of cut carnation scent significantly. The combination of sucrose and conventional chemical treatments, including preservatives containing silver thiosulfate or slow-release chlorine to prevent ethylene-induced flower senescence or bacterial growth in the vase water used during transport, resulted in scent improvement, along with the expected effects of the chemical treatments. Overall, these results suggest that wet transport with sucrose is a promising technique for improving the scent of cut carnations.