Aluminum Sulfate as Pulsing Preservative for Export-oriented Rose Flowers under Bahir Dar Conditions, Northwestern Ethiopia

Abstract

Rose is one of the most important cut flowers in Ethiopia produced mostly for export markets. Maintaining the postharvest life is the most challenging issue for most of the floricultural enterprises in the country. Two sets of experiments were therefore conducted in Tana Flora PLC farm, one of the biggest cut rose producers in Bahir Dar, Northwestern Ethiopia with the objectives of identifying the appropriate concentration of aluminum sulfate as pulsing preservative to maintain the vase life of export oriented rose flowers. In the first set, aluminum sulfate alone and in combination with calcium hypochlorite at different concentrations including the experience of Tana Flora PLC, sucrose and distilled water as control were tested for their influence on physiological status of `Maracuja` rose flowers. In the second set, the best performed pulsing preservative (aluminum sulfate alone) was tested at four concentrations (0ppm, 125ppm, 250ppm and 375ppm) to identify the optimum concentration. After pulsing for about 30 hours, six cut flowers were put in 250 ml glass flask containing distilled water. The flasks with flowers were arranged in Complete Randomized Design with three replications and kept in vase life testing room of Tana Flora PLC. According to the results obtained, aluminum sulfate at the concentration of 250ppm was the best in prolonging the vase life, in producing bigger flower head and maintaining the freshness of flowers. The reduction in percent fresh weight during the vase life of flowers was minimal in 250ppm aluminum sulfate pulsed flowers. The prolonged vase life of aluminum pulsed flowers is due to better water uptake and thus stabilized water balance in the flowers as observed in this study. Thus, it is advised to incorporate aluminum sulfate in flower holding solution at the concentration of 250ppm to maintain the freshness and vase life of export oriented rose flowers and those for local market in the study area.