The Effect of Cut Stem Length Treatment on Vase Life and Water Relations of Rose Flower (Rosa hybrida) cv. ‘Bingo White’

One of the most important factors in controlling the quality of fresh flowers is stem length because it is a major determinant of cut stem productivity. The grading and marketing of most cut flowers, like roses, are generally based on stem length. The present study aimed to evaluate the effects of cut rose flower stem length on vase life and water balance of rose cv. ‘Bingo White’ in a factorial experiment based on a Completely Randomized Design (CRD). Cut stem length was used at four levels of 25, 35, 45, and 55 cm kept in 50 mg/L sucrose sodium hypochlorite solution at two levels of 0 and 2% as preservative solutions with three replications at 23 ± 2°C with 65 ± 5% relative humidity and 12μmol/m2 s of light intensity (supplied by cool white fluorescent lamps) for 12 hours up to the end of vase life. Some qualitative and quantitative characteristics including vase life, flower and leaf water potential, ion leakage, membrane stability index (MSI), and leaf stomatal conductance were recorded. The results showed that the longest vase life (17 days) was significantly (P < 0.01) observed at the lowest stem length (25 cm) and the shortest vase life (10 days) was related to the highest stem length (55 cm). The lowest rate of leaf and petal ion leakage was significantly (P < 0.05) observed in the lowest stem length (25 cm). The stem lengths of 35 and 45 cm, however, did not significantly differ from the stem length of 25 cm. The lowest rate of leaf and petal membrane stability index was significantly (P < 0.05) related to 55 cm stem length. The highest rate of flower and leaf water potential was significantly (P < 0.01) obtained from 35 cm stem length as compared with other treatments. Stomatal conductance decreased over time, but it was not affected by stem length treatments significantly. Generally, our results showed that the shorter cut stem length treatment (25 cm) with the sucrose solution (2%) not only had the greatest effect on extending vase life but it also improved the water status, decreased the ion leakage, and increased the flower membrane stability index.