Homemade Floral Preservatives Affect Postharvest Performance of Selected Specialty Cut Flowers

Abstract

Effects of homemade or commercial floral preservatives, applied as 48-hour grower treatment or continuous retailer/consumer application, were studied on cut ‘ABC Blue’ lisianthus (Eustoma grandiflorum), ‘Maryland Plumblossom’ snapdragon (Antirrhinum majus), ‘Mid Cheerful Yellow’ stock (Matthiola incana), and ‘Deep Red’ Benary’s zinnia (Zinnia violacea). Cut stems were placed in solutions containing 500 mL·L−1 lemon/lime soda (soda); 6 mL·L−1 lemon juice plus 20 g·L−1 sugar (lemon juice); 100 mg·L−1 citric acid plus 20 g·L−1 sugar plus 200 mg·L−1 aluminum sulfate (C-AS); 400 mg·L−1 citric acid plus 20 g·L−1 sugar alone (citric acid), or combined with either 0.5 mL·L−1 quaternary ammonium chloride (C-QA), or 0.007 mL·L−1 isothiazolinone (C-IS); 10 mL·L−1 Floralife Clear Professional Flower Food (Floralife); or 10 mL·L−1 Chrysal Clear Professional 2 (Chrysal), dissolved in tap water, which was also used as control without any added compound. Cut stems of lisianthus and stock had longest vase lives (22.1 and 12.7 days, respectively) when placed in C-IS continuously, while snapdragon and zinnia stems had longest vase lives (22.3 and 16.3 days, respectively) when placed in C-QA solution continuously. Continuous use of soda extended vase life of cut lisianthus, snapdragon, and stock stems, but not zinnia, compared with tap water. Citric acid extended the vase life of lisianthus and stock when used continuously and of zinnia when used for 48 hours. Use of C-AS or lemon juice either had no effect or reduced vase life of the tested species, except lemon juice increased zinnia vase life when used as a 48-hour treatment. Stems of lisianthus, stock, and zinnia placed continuously in C-IS, C-QA, or citric acid had high solution uptake. No significant differences were observed for vase life of all tested species with short duration (48 hours) application of solutions, except 48-hour use of citric acid or lemon juice increased zinnia vase life compared with tap water. Overall, continuous vase application of the homemade preservatives resulted in longer vase life extension than 48-hour treatment. Among tested preservative recipes, C-IS, C-QA, soda, or citric acid demonstrated best postharvest performance of tested species. However, recipes containing C-AS or lemon juice had detrimental effects and should not be used for handling cut stems of tested species.