Melatonin pulse treatment optimization: boosting vase life and postharvest quality in cut roses (Rosa hybrida cv. Samurai).

Cut roses (Rosa hybrida cv. Samurai) exhibit rapid postharvest senescence, limiting vase life and commercial value. This study optimized melatonin application by comparing pulse (30-min immersion) and continuous (vase solution) methods at 0.1 mM and 1 mM concentrations. The 0.1 mM pulse treatment extended vase life by 61% (9.67 vs. 6.00 days in control), improved flower quality score to 5.00, increased flower diameter by 18%, elevated chlorophyll and anthocyanin contents, and reduced electrolyte leakage by 43%. Strong positive correlations (r = 0.71-0.94, P < 0.001) were observed between these parameters and vase life. Higher concentrations (1 mM) and continuous application were less beneficial. No gray mold symptoms were observed in any treatment during the vase period. These results demonstrate that a brief 0.1 mM melatonin pulse effectively delays senescence and primes endogenous antioxidant defenses, providing one of the first a resource-efficient protocol that warrants further economic and commercial evaluation.