Introduction:

Cut roses (Rosa spp.) are among the most widely cultivated and economically significant ornamental flowers worldwide, with particularly high cultural and commercial importance in Iran. These flowers are highly valued not only for their aesthetic appeal and fragrance but also for their role in the floriculture industry, which contributes significantly to local economies. Despite their popularity, a major limitation in the cut flower industry is the relatively short vase life of roses, which is often further reduced during transportation, storage, and marketing. Early senescence, petal wilting, and stem bending are common postharvest problems that negatively affect flower quality and market value. Consequently, finding effective, safe, and cost-efficient preservative solutions to extend the vase life and maintain the quality of cut roses has been a long-standing challenge in horticultural research. Various strategies have been investigated, including the use of sugars, antimicrobial agents, and plant growth regulators. Sugars serve as an energy source and help maintain osmotic balance, antimicrobial agents can reduce microbial blockage in xylem vessels, and growth regulators can delay senescence by stabilizing cellular membranes and regulating physiological processes. In this context, combining sucrose with either natural compounds such as propolis or synthetic regulators like 2,4-dichlorophenoxyacetic acid (2,4-D) may offer a promising approach for improving postharvest performance of cut roses. Therefore, the present study aimed to evaluate the effects of sucrose, propolis, and 2,4-D, alone and in combination, on the vase life, water relations, and quality traits of cut roses under controlled laboratory conditions.



Materials and Methods:

The experiment was conducted in the Horticultural Sciences Laboratory of Ferdowsi University of Mashhad, Iran, using a randomized complete block design (RCBD) with three replications and two observation periods. Six treatment solutions were evaluated: T1) distilled water (control), T2) distilled water + 3% sucrose, T3) distilled water + 3% sucrose + 0.5% propolis, T4) distilled water + 3% sucrose + 1% propolis, T5) distilled water + 3% sucrose + 2,4-D (5 ppm), and T6) distilled water + 3% sucrose + 2,4-D (10 ppm). The sucrose concentration was chosen based on its optimal osmotic and nutritional effects on cut flowers, while the propolis concentrations were selected due to their reported antimicrobial properties. The 2,4-D concentrations were based on previous studies showing effectiveness in delaying senescence in ornamental plants. Tofordi (96% purity) and sucrose (3%) were purchased from Betagen Company (Mashhad, Iran), whereas propolis was collected from honeybee hives in Firouzi village, Golbahar, Mashhad, Iran. Flowers were harvested at commercial maturity, immediately recut under water to prevent xylem blockage, and placed in their respective treatment solutions. Vase life, relative fresh weight, petal water content, flower and stem diameter, solution uptake, and chlorophyll content (chlorophyll a and b) were measured at regular intervals during the observation period using standard laboratory techniques. All measurements were conducted under controlled temperature, humidity, and light conditions to minimize environmental variability.



Results and Discussion:

All treatments significantly improved the vase life of cut roses compared with the control, which had an average vase life of 5.7 days (p < 0.05). The T6 treatment (distilled water + 3% sucrose + 10 ppm 2,4-D) resulted in the longest vase life of 9.3 days, followed by T3 and T4 treatments (approximately 9.0 days each). The T2 treatment (3% sucrose) increased average vase life to 8.67 days and also improved flower and stem diameter (260.44 mm and 180.6 mm, respectively), as well as relative fresh weight and petal water content. T3 treatment (0.5% propolis + 3% sucrose) showed the highest stem diameter, solution uptake, and chlorophyll b content, indicating enhanced water relations and photosynthetic potential. Similarly, T4 (1% propolis + 3% sucrose) extended vase life to about 9 days, suggesting a dose-dependent effect of propolis on maintaining postharvest quality. The T5 treatment (5 ppm 2,4-D + 3% sucrose) resulted in the highest petal water content and relative fresh weight, highlighting the role of growth regulators in delaying senescence and maintaining tissue turgor. Overall, combining sucrose with either propolis or 2,4-D effectively improved water balance, reduced vascular blockage, and delayed senescence, which collectively contributed to prolonged vase life and enhanced flower quality. Sucrose likely provided an energy source for metabolic activity while maintaining osmotic potential, propolis contributed antimicrobial activity to prevent microbial-induced xylem blockage, and 2,4-D acted as a senescence-delaying growth regulator. These findings demonstrate that integrated postharvest solutions combining sugars, natural extracts, and growth regulators can substantially improve the commercial value and longevity of cut roses.



Acknowledgement:

The authors wish to express their sincere gratitude to Ferdowsi University of Mashhad, Mashhad, Iran, for providing laboratory facilities to conduct this study.