(39) Chlorine Dioxide Treatment Extends Longevity of Cut Gerbera Flowers

• Published in: HortScience Vol. 40; no. 4; p. 1029
• Main Authors: Macnish, Andrew J, Leonard, Ria T, Nell, Terril A
• Format: Journal Article
• Language: English
• Published: 01.07.2005
• DOI: 10.21273/HORTSCI.40.4.1029B
• ISSN: 0018-5345

The vase life of many cut flowers is often limited by bacterial occlusion of stem bases. In this study, we tested the efficacy of a novel antimicrobial agent, aqueous chlorine dioxide (ClO 2 ), to extend the longevity of cut Gerbera flowers by reducing the number of bacteria in vase water. Commercially mature and freshly cut Gerbera jamesonii `Monarck' flowers were placed into clean vases containing deionized water and 0, 2, 5, 10, 20, and 50 μL·L -1 ClO 2 . Stems were then maintained in solutions at 21 ± 0.5 °C and 42 ± 11% relative humidity until the end of vase life. Inclusion of 2, 5, and 10 μL·L -1 ClO 2 in vase water had beneficial effects on flower longevity. For instance, treatment with 5 and 10 μL·L -1 ClO 2 extended flower longevity by 1.4-fold or 3.7 days, as compared to control flowers (0 μL·L -1 ClO 2 ). In contrast, exposure to the higher concentrations of 20 and 50 μL·L -1 ClO 2 did not extend flower vase life. Relative to control flowers, treatment with 10 μL·L -1 ClO 2 delayed the onset of detectable bacterial colonization of vase solutions from day 3 to day 6 of vase life. However, this ClO 2 treatment did not reduce the number of bacteria that subsequently accumulated in vase water as compared to control flowers. Treatment with 10 μL·L -1 ClO 2 also increased rates of solution uptake by stems and reduced the loss of flower fresh weight over time. These results highlight the potential use of ClO 2 treatments to extend the postharvest longevity of Gerbera flowers.