The effect of cut branch length treatment on flower life and water relations of rose cultivar 'Bingo White'

One ​​of the important factors in quality control of fresh flowers is branch length, which is an important determinant of cut branch performance, and the grading and marketing of many cut flowers, such as roses are based on branch length.  The aim of this study was to investigate the effects of different lengths of cut branches and sucrose solution on the life of the flower and water balance of rose cultivar ’Bingo White‘. This experiment was conducted in ­ A factorial design was carried out in a completely randomized design with four different levels of branch length (25, 35, 45, and 55 cm) and two levels of sucrose (0 and 2%) along with sodium hypochlorite at a concentration of 50 mg/L in three replications, at a temperature of 2±23°C, a relative humidity of 5±65%, and a light intensity of 12 μmol/m2/s (cool white fluorescent lamps) with 12 hours of lighting until the end of the vase life. In this experiment, various qualitative and quantitative parameters such as: vase lifespan, leaf and flower water potential, leaf and ion leakage, leaf and petal cell membrane stability, and leaf stomatal conductance were evaluated. The results showed that the highest vase life (17 days) was observed in the shortest branch length treatment (25 cm) in a vase solution containing 2% sucrose and the lowest vase life (10 days) was observed in the longest branch length (55 cm) significantly (P < 0.01). The lowest leaf and petal ion leakage was observed significantly (P < 0.05) in the shortest branch length (25 cm), although there was no significant difference between other branch length levels including 35 and 45 cm with the 25 cm level. The lowest cell membrane stability index was significantly (P < 0.05) in the longest branch length (55 cm) compared to other branch lengths. The highest water potential of leaf and flower was significantly (P <0.01) observed in the 35 cm branch length treatment compared to other lengths. Leaf stomatal conductance decreased over time and was not significantly affected by the branch length treatment. The lowest membrane stability of leaf and petal was observed in the 55 cm stem length and there was no significant difference between the other lengths. Stomatal conductance decreased over time and was not affected by the treatments. Overall, our results showed that, the 55 cm stem length treatment Shorter branches (25 cm) and 2% sucrose solution not only had the greatest effect on increasing vase life, but also improved water status, reduced ion leakage, and increased petal cell membrane stability.