Extended Storage of Cut Flowers Using Sub-zero Temperature

Abstract

The cut flower industry needs postharvest techniques that allow for extended storage of fresh cut flowers to meet consumer demands. We compared the use of a sub-zero storage temperature (−0.6 °C) to maintain viable flowers with improved or comparable vase life to flowers stored at the industry standard (4 °C). The vase life of 17 commercially important cut flower species, alstroemeria (Alstroemeria), anemone (Anemone coronaria), campanula (Campanula medium), carnation (Dianthus caryophyllus), chrysanthemum (Chrysanthemum), delphinium (Delphinium elatum), freesia (Freesia), gerbera (Gerbera jamesonii), gypsophila (Gypsophila paniculata), larkspur (Consolida), lily (Lilium), lisianthus (Eustoma grandiflorum), ranunculus (Ranunculus asiaticus), rose (Rosa hybrida), stock (Matthiola incana), sunflower (Helianthus annuus), and tuberose (Polianthes tuberosa), when stored dry at −0.6 °C for durations of 4, 8, and 12 weeks was comparable to or longer than that when stored at 4 °C. Tuberose stems were not viable after holding for any storage duration or temperature. Experiment 2 compared the use of a prestorage pulsing treatment of water, hydrating solution, or holding solution containing carbohydrates for 8 hours before extended storage for carnation, chrysanthemum, delphinium, lily, and rose stems. Stems of carnation benefitted from pulsing with a hydrating solution and maintained vase life similar to that of nonstored control stems when stored for 4 weeks at −0.6 °C. Conversely, rose stems only maintained vase life similar to that of nonstored control stems when held at 4 °C for all pulsing solutions. Lily and chrysanthemum stems had a decline in vase life with all pulsing solutions and only remained viable after 8 weeks of storage when held at −0.6 °C. Additionally, stored chrysanthemum and lily stems had a longer vase life when stored at −0.6 °C than that when held at 4 °C after 4 and 8 weeks of storage, respectively, with all pulsing solutions. Delphinium stems were not viable after any storage duration. Experiment 3 further evaluated carnation, lily, and rose stems with and without a prestorage acclimation period at 4 °C for either 24 hours or 1 week before extended storage of 4, 6, or 8 weeks. Holding stems at 4 °C for 1 week before extended storage reduced the vase life of all species. Rose stems remained viable after 8 weeks of extended storage when held at −0.6 °C, but only when no prestorage hold was used. Lily and rose stems were not viable beyond 4-week storage durations when held at 4 °C, but they remained viable with no prestorage holding period after 8 weeks at −0.6 °C. Carnation stems maintained a longer vase life irrespective of a prestorage holding period when stored at −0.6 °C. Through this analysis, we showed that many species of cut flowers may be held at a sub-zero temperature with vase life better than or comparable to that with the industry standard of 4 °C.