Effects of Acacia Gum on Post-harvest Quality of Cut Flowers

Abstract

The U.S. cut flower market has shifted from domestically grown to imported products. Because of the extended time between harvest and reaching the consumer, there is need for improved post-harvest handling methods, especially in less developed countries. Acacia gum appeared to be promising in its use as a floral preservative. A first experiment evaluated a range of concentrations and application methods of Acacia gum for its effectiveness in extending the vase life of fresh cut flowers. ‘Maryland True Pink’ and ‘Maryland Dark Red’ snapdragons (Antirrhinum majus) along with ‘Guardian White’ and ‘Guardian Mid Blue’ delphiniums (Delphinium elatum) were grown in a greenhouse, harvested, and treated with 5%, 10%, or 20% concentration of Acacia gum mixed in water using eight different application methods. The vase life of ‘Maryland True Pink’snapdragon was extended by dipping flowers in 10% or 20% Acacia gum. Results for ‘Maryland Dark Red’ and delphiniums were variable. A second experiment screened widely used cut flowers for the efficacy of Acacia gum in extending vase life. Twelve cut flower species were acquired from a local wholesale floral supplier. Flowers were treated by dipping in 5% or 10% Acacia gum and placed in reverse osmosis water or Floralife preservative. Results of this study show that Acacia gum treatments were at best comparable too, but not better than the Floralife standard. Acacia gum showed no benefit as a floral preservative over what is currently used. A third experiment tested the effects of Acacia gum applied before or after storage in a cooler, and with or without Floralife, on vase life of two cut flower species. ‘ABC 1-3 Purple’ lisianthus (Eustoma grandiflorum) and ‘Super Parfait Raspberry’ dianthus (Dianthus chinensis) were grown in a greenhouse, harvested, and treated with Acacia gum (5% or 10%) before or after storage in a cooler. Storage times were 0, 4, 8, or 12 days. Dianthus treated with Acacia gum showed varied results. Regardless of preservative treatment, the longer flowers were stored, the longer they kept their aesthetic value after removal from cooler. Acacia gum had no effect on the number of days to aesthetic loss of lisianthus. This research indicates that overall, Acacia gum is at best comparable to Floralife, and showed no benefit over currently used floral preservatives.