ARS | Publication request: An Alternative postharvest handling strategy for cut flowers-dry handling after harvest

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2009
Publication Date: December 1, 2009
Repository URL: http://www.actahort.org/members/showpdf?session=15566
Citation: Macnish, A., De Theije, A., Reid, M.S., Jiang, C. 2009. An Alternative postharvest handling strategy for cut flowers-dry handling after harvest. Acta Horticulturae. 847: 215-221.

Interpretive Summary: It is customary to hydrate cut flowers after harvest. This practice can restore the loss in flower turgidity that occurs during dry handling of stems in the greenhouse and help limit water deficit stress associated with subsequent dry shipment. Hydration after harvest also ensures continued growth and development (e.g. petal expansion, flower opening) of cut flowers. In addition, hydration provides an opportunity to administer water soluble chemical inhibitors of ethylene action (e.g. silver thiosulfate) and leaf senescence (e.g. cytokinin) to flowers. Although immediate postharvest hydration is thought to extend the longevity of flowers by reducing desiccation, there has been no detailed study of this hypothesis. Given the considerable cost of infrastructure and time taken to provide postharvest hydration it seems important to validate this practice. Indeed, it is possible that hydrating some flower species prior to conventional dry shipment may not always be desirable. Hydrating flowers after harvest may increase the risk of introducing bacterial occlusions into stems, either directly from contaminated solutions or by continued growth of bacteria in xylem conduits during dry shipment. In the current study, rose flowers were used to test the hypothesis that dry handling of harvested stems would not compromise flower quality and longevity. We harvested rose flowers from commercial farms near Bogotá, Colombia and Quito, Ecuador. Flowers were either hydrated as per conventional practice, or not provided with immediate postharvest hydration. They were then processed and transported to Davis, California, following standard commercial practices. Despite substantial loss of water during transport, dry-handled flowers rehydrated fully, and performed at least as well in the vase as flowers handled according to the standard protocol. Our data suggest that the value of immediate hydration of harvested flowers should be carefully examined, not only for roses, but for other important species.

Technical Abstract: The most traditional first step after harvesting flowers is to place the cut stems into water or a postharvest solution. Although this step is thought to reduce desiccation, and thereby extend postharvest life, there has been no detailed study of this hypothesis. We harvested rose flowers from commercial farms near Bogotá, Colombia and Quito, Ecuador. Flowers were either hydrated as per conventional practice, or not provided with immediate postharvest hydration. They were then processed and transported to Davis, California, following standard commercial practices. Despite substantial loss of water during transport, dry-handled flowers rehydrated fully, and performed at least as well in the vase as flowers handled according to the standard protocol. Our data suggest that the value of immediate hydration of harvested flowers should be carefully examined, not only for roses, but for other important species.