Extension of the Vase Life in Cut Roses by Treatment with Glucose, Isothiazolinonic Germicide, Citric Acid and Aluminum Sulphate Solution

Abstract

Cut rose (Rosa hybrida L.) cv. Rote Rose was treated with glucose, fructose or sucrose at 10 g L -1 in combination with a commercial preparation of isothiazolinonic germicide (a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one; CMI/MI; Legend MK) at 0.25, 0.5 or 1 mL L -1 . To stabilize germicidal activity, the solution was acidified by the addition of citric acid to a final concentration at 30 mg L -1 . Of the sugars, glucose was the most effective in extending the vase life, followed by fructose. CMI/MI was most optimal at 0.5 mL L -1 . The addition of aluminum sulphate at 50 mg L -1 to glucose plus CMI/MI considerably extended the vase life of cut roses more than glucose plus CMI/MI. Based on these results, a formulation comprising 10 g L -1 glucose, 0.5 mL L 8-hydroxyquinoline sulphate (HQS). Treatment with GLCA extended the vase life of all the tested cultivars more than glucose plus HQS. Hydraulic conductance of stem segments in the control 'Rote Rose' roses decreased rapidly after harvest, but those for GLCA and glucose plus HQS were maintained at near their initial levels. The extension of vase life in cut roses by the addition of GLCA is attributed to the supply of sugars and the suppression of vascular occlusion without toxicity to cut flowers.

Influence of pulsing biocides on vase life of cut roses (<i>Rosa hybrida</i> L.)

“…The significant reduction in vase solution absorbance in pulsing treatments of NaOCl and HQS could be due to the antimicrobial effect of these biocides. HQS is a wellknown germicide although it is toxic to some rose cultivars leading to shortening of their vase life (Ichimura et al, 2006). Knee (2000) also reported a reduction in solution absorbance (0.057) of 'Classy' roses treated with HQC.…”

Postharvest performance of cut marigold, rose, and sunflower stems as influenced by homemade and commercial floral preservatives

“…Jones and Hill (1993), Kuiper et al (1995), Elhindi (2012), and Locke (2010) also reported the significance of carbohydrates and germicides for extending postharvest longevity of cut flowers. More specifically, aluminum sulfate has been reported as effective for vase life extension of several cut species, such as lisianthus (Liao et al, 2001) and roses (Ichimura et al, 2006). Addition of Kathon CG or Greenshield effectively controlled bacterial populations in the vase solutions (visual observation).…”

“…It lowers the pH of cell sap and reduces vascular blockage, thereby improving water uptake and extending longevity. Similarly, citric acid also encourages floral opening and maintains postharvest quality of cut tuberose spikes (Jowkar and Salehi, 2006), and aluminum sulfate is extensively used as a biocide for cut lisianthus (Liao et al, 2001), roses (De Stigter, 1981), and many other cut flower species and stabilizes petal anthocyanin levels to improve the keeping quality and vase life of cut roses (Ichimura et al, 2006). Several other common products have been used in homemade floral preservatives.…”

“…However, antimicrobial compounds must be used along with sugars to prevent microbial build-up in the solutions (van Doorn, 1997). Among these biocides, silver compounds such as silver nitrate and silver thiosulfate, chlorine compounds like sodium hypochlorite, sodium dichloroisocyanurate, and several other compounds like cobalt chloride, 8-hydroxyquinoline citrate or sulfate, Physan 20 (Greenshield), or Kathon CG are used to prevent microbial proliferation in vase solutions (Ichimura et al, 2006). Due to environmental hazards associated with silver compounds and 8-hydroxyquinoline citrate or sulfate, and the short-term effectiveness of chlorine compounds, Greenshield and Kathon CG can be excellent options for incorporation into floral preservatives.…”

When is a Vase Solution Biocide not, or not only, Antimicrobial?

“…The dictionary definition of an antimicrobial is "active against microorganisms" (Pearsall, 1998). Among the principle antimicrobial compounds that have been used to extend the vase life of cut flowers are: (i) chlorine and bromine compounds, such as sodium dichloroisocyanuric acid (Na-DICA) Knee, 2000;Van Doorn et al, 1990;Xie et al, 2007) and sodium hypochlorite (NaOCl) (Van Doorn et al, 1990); (ii) hydroxyquinoline (HQ) compounds, such as 8-hydroxyquinoline citrate (HQC) (Knee, 2000;Marousky, 1969;Van Doorn et al, 1990) and 8-hydroxyquinoline sulphate (HQS) (Hussein, 1994); (iii) quaternary ammonium compounds, such as benzalkonium chloride (n-alkyl dimethylbenzyl ammonium chloride) where the alkyl group may vary from C 8 H 17 to C 18 H 37 (Knee, 2000;Van Doorn et al, 1990); the proprietary compound Physan-20 (n-alkyl (C 12 and C 14 ) dimethyl ethylbenzyl ammonium chloride) (Doi and Reid, 1995); Isocil or Legend MK, where 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (CMI/MI) are the active ingredients (Ichimura et al, 2006;Knee, 2000); Dantogard…”