Effects of Some Chemicals on Vase Life of Some Cut Flowers I. Effect of 8-Hydroxyquinoline Sulfate, Silver Nitrate, Silver Nano Particles and Chitosan on Vase Life and Quality of Cut Rose Flowers (Rosa hybrida. Cv. “Black Magic”)

This investigation was carried out during 2015 and 2016 seasons to determine whether the selected chemical agents could be used to improve the postharvest quality of Rosa hybrida L.cv. “Black Magic” cut flowers. Freshly cut flowers were placed in glass cylinders containing 100 ml of preservative solutions [8-hydroxyquinoline sulfate (8-HQS) at 200 ppm, silver nitrate (AgNO3) at 10 ppm, Chitosan at 50, 75 or 100 ppm silver nano-particles (SN) at 5, 10 or 15 ppm, and distilled water as a control treatment].All preservative solutions and the control treatment included sucrose at 20 g/l. Compared to the control, treatments which contained of (AgNO3) or (SN) improved the quality and vase life of the flowers. They were more effective in promoting water uptake, increasing fresh weight of the flower and water balance so that the vase life of cut flowers were extended to 13.67 and 12 days during the first and second seasons, respectively. The results of bacterial count in the vase solution and the Scanning Electron Microscopy (SEM) pictures of the cut base of the stem indicated that (AgNO3) or (SN) strongly reduced bacterial population in both the vase solution and the cut stem base. The results indicated that using (AgNO3) or (SN) combined with 20 g/l sucrose could be used as a commercial cut flower preservative solution for prolonging the vase life and enhancing post-harvest quality of selected rose cut flowers.