Vase Water Research Articles

SPRAYING OF SUCROSE ON THE GREENHOUSE-GROWN ROSE AND ITS EFFECTS ON THE VASE LIFE OF THE CUT FLOWERS CV. ALEXANDER

SPRAYING OF SUCROSE ON THE GREENHOUSE-GROWN ROSE AND ITS EFFECTS ON THE VASE LIFE OF THE CUT FLOWERS CV. ALEXANDER

Treatment with chlorine dioxide extends the vase life of selected cut flowers

The accumulation of bacteria in vase water is often associated with premature senescence in many cut flower species. In the present study, we tested the efficacy of aqueous chlorine dioxide (ClO 2) to extend flower display life by preventing the build-up of bacteria in vase solutions. The addition of 2 or 10 μL L −1 ClO 2 to clean deionized water extended the vase life of Alstroemeria peruviana ‘Senna’, Antirrhinum majus ‘Potomic Pink’, Dianthus caryophyllus ‘Pasha’, Gerbera jamesonii ‘Monarch’, Gypsophila paniculata ‘Crystal’ and ‘Perfecta’, Lilium asiaticum ‘Vermeer’, Matthiola incana ‘Ruby Red’ and Rosa hybrida ‘Charlotte’ flowers by 0.9–13.4 d (7–77%) relative to control (i.e. 0 μL L −1 ClO 2) stems. The beneficial effects of ClO 2 treatment were associated with a reduction in the accumulation of aerobic bacteria in vase water and on cut surfaces of flower stems. ClO 2 treatment was also effective in maintaining or extending the vase life of A. majus ‘Potomic Pink’, Dendrathema × grandiflorum ‘Albatron’, G. paniculata ‘Perfecta’ and M. incana ‘Ruby Red’ flowers even when stems were placed into water containing 10 11 CFU L −1 bacteria. The efficacy of 10 μL L −1 ClO 2 in vase water containing 0.2 g L −1 citric acid and 10 g L −1 sucrose to extend the display life of G. jamesonii ‘Lorca’ and ‘Vilassar’ flowers was equal to or greater than other tested biocides (i.e. aluminum sulfate, dichloroisocyanuric acid, 8-hydroxyquinoline sulfate, Physan 20™, sodium hypochlorite). Taken collectively, the results of the present study highlight the potential of aqueous ClO 2 for use as an alternative antibacterial agent in flower vase solutions.

Monitoring bacterial populations in an agricultural greenhouse production system irrigated with reclaimed wastewater

SummaryWhile much attention has been given to evaluations of potential health risks associated with the irrigation of crops by treated urban waste water in open fields, no information is available concerning irrigation with waste water in closed greenhouses in soilless cultivation. The fate of human pathogens originating from waste water applied in a greenhouse environment, and throughout the marketing chain, has never been assessed. The aim of this study was to examine the fate of indicators of faecal pollution in a greenhouse production system for roses irrigated with waste water under soilless cultivation. Rose plants grown in mineral (perlite) or organic (coconut fibre) soilless media were irrigated with potable or secondary (treated) urban waste water. Prior to chlorination, 2 CFU Escherichia coli ml–1, a bacterium used as an indicator of faecal pollution, were detected in the treated effluent water source. Following routine chlorination, no E. coli were detected in the source water, fertigation solution, or soilless media. In addition, E. coli was not found on leaf surfaces, in the air inside or outside the greenhouse, or in the vase water of the cut-flowers. The 0.6 – 0.7 CFU E. coli ml–1 identified in the drainage solution demonstrated that some viable E. coli cells survived chlorination, and accumulated to reach detectable levels in the leachates. Chlorination also suppressed the population of coliforms and total aerobic bacterial counts throughout the greenhouse water system, as well as all total fungal and yeast counts in the source water.

EFFECT OF PROMOTER AND INHIBITORS OF PHENYLALANINE AMMONIA-LYASE ENZYME ON STEM BENDING OF CUT GERBERA FLOWERS

EFFECT OF PROMOTER AND INHIBITORS OF PHENYLALANINE AMMONIA-LYASE ENZYME ON STEM BENDING OF CUT GERBERA FLOWERS

Vascular blockage in cut roses in a suspension of Pseudomonas fluorescens

SummaryTo analyse quantitatively the relationships between cut rose (Rosa hybrida L. ‘Pascha’) vase-life, the onset of cavitation, plant water potential, and bacterial concentrations in the vase water, rose stems were placed in water containing different concentrations of Pseudomonas fluorescens 2892 tetr rif r. There was a significant correlation (P = 0.0009) between cut rose vase-life and the concentration of bacteria in the vase water. As the number of bacteria in the vase water increased, the rate of senescence also increased. The water potential for roses in the bacterial suspension (at 8.50 log10 CFU ml–1) proceeded to drop constantly after 5.17 h in the vase solution, with the water potential falling to as low as -2.35 MPa by the end of the experiment (at 117 h). In contrast, the water potential of roses in deionised water dropped from -0.419 MPa at 5.17 h, to only –0.663 MPa after 117 h. When roses were stood in a bacterial suspension (at 8.5 log10 CFU ml–1) for 30 h, 63.8% of the total cumulative cavitation events were seen, while roses stood in deionised water exhibited only 26.8% of the total cavitation events. Uptake of acid fuchsin and the movement of tagged P. fluorescens 2892 in the xylem indicated that bacteria did not travel beyond the open-ended xylem vessels and were generally restricted to the first 50 mm from the cut end of the stem.

Changes in pigment content and surface micro-morphology of in cut carnation flower petals under high-temperature conditions

SummarySenescence of carnation petals progresses gradually, even when climacteric ethylene production is blocked. The most distinct visible changes in the later stages of petal senescence are a fading of flower colour and a change in appearance (“freshness”). Cut carnation cv. Excerea flowers treated with silver thiosulphate were kept in vase solutions with or without 1% (w/v) sucrose under high-temperature conditions (32ºC). Changes in pigment content and the micro-morphology of epidermal cells in petals were monitored. The main pigment in ‘Excerea’ carnation petals was pelargonidin-3-malylglucoside (Pg3MG). A 48 – 70% reduction in Pg3MG occurred between day-5 and day-15 in petals kept under high-temperature conditions. Petal colour changes, as determined by lower C* and hº values using a colourimeter, were consistent with the reduction in Pg3MG content. Sucrose [1% (w/v)] in the vase water was effective at inhibiting the reduction in pigment content in petals kept under high-temperature conditions. An enlargement of epidermal cells occurred on both the abaxial and adaxial surfaces of petals between day-5 and day-15, irrespective of petal position, temperature conditions, or the composition of the vase solution. This enlargement in epidermal cells could cause the change in appearance of the flowers.

POTENTIAL OF CHLORINE DIOXIDE TO EXTEND THE LONGEVITY OF CUT FLOWERS

The postharvest longevity of fresh-cut flowers is often limited by the accumulation of bacteria in vase water and flower stems. Aqueous chlorine dioxide is a strong biocide with potential application for sanitizing cut flower solutions. We evaluated the potential of chlorine dioxide to prevent the build-up of bacteria in vase water and extend the longevity of cut Matthiola incana `Ruby Red', Gypsophila paniculata `Crystal' and Gerbera jamesonii `Monarch' flowers. Fresh-cut flower stems were placed into sterile vases containing deionized water and either 0.0 or 2 μL·L–1 chlorine dioxide. Flower vase life was then judged at 21 ± 0.5 °C and 40% to 60% relative humidity. Inclusion of 2 μL·L–1 chlorine dioxide in vase water extended the longevity of Matthiola, Gypsophila and Gerbera flowers by 2.2, 3.5, and 3.4 days, respectively, relative to control flowers (i.e., 0 μL·L–1). Treatment with 2 μL·L–1 chlorine dioxide reduced the build-up of aerobic bacteria in vase water for 6 to 9 days of vase life. For example, addition of 2 μL·L–1 chlorine dioxide to Gerbera vase water reduced the number of bacteria that grew by 2.4- to 2.8-fold, as compared to control flower water. These results confirm the practical value of chlorine dioxide treatments to reduce the accumulation of bacteria in vase water and extend the display life of cut flowers.

Effects of the Temperature of Vase Water on the Vase Life of Cut Rose Flowers

Cut rose (Rosa hybrida L.) ‘Sonia’ flowers were placed in vases of which water temperatures were kept at 10, 15 and 23°C under constant air temperature of 23°C. Vase life of cut roses became longer with lowering water temperature; the vase life was 5.2, 6.7 and 7.5 days at 23, 15 and 10°C, respectively. Fresh weight of cut flowers increased over the first 3, 4 and 5 days during the experimental period at 23, 15 and 10°C, respectively and decreased thereafter. Temperature of flower part was very slightly lowered by lowering water temperature. Hydraulic conductance of stem segments decreased on the third day after harvest, and this decrease was suppressed by lowering the temperature of vase water. Bacterial number in vase water increased with time, and this increase was suppressed by lowering the temperature of vase water. These results show that low temperature of vase water might improve the stem water relation and extended the vase life of cut rose flowers.

Bacteria in flower vase water: incidence and significance in general ward practice.

Culture of flower vase water from wards in the David Lewis Northern Hospital, Liverpool, revealed large numbers of potentially pathogenic bacteria. The types of organisms isolated may reflect the particular ecology of this hospital as they differed in some ways from those reported from other centres. The incidence of wound infections during the period of study was low (5-2 per cent) despite the regular overgrowth of bacteria in flower vases, and there did not appear to be any definite correlation between the types of bacteria isolated from flower vase water and those responsible for wound infections. The addition of hydrogen peroxide to flower vases proved a very effective antiseptic and is recommended for general use as a precautionary measure.

(39) Chlorine Dioxide Treatment Extends Longevity of Cut Gerbera Flowers

The vase life of many cut flowers is often limited by bacterial occlusion of stem bases. In this study, we tested the efficacy of a novel antimicrobial agent, aqueous chlorine dioxide (ClO2), to extend the longevity of cut Gerbera flowers by reducing the number of bacteria in vase water. Commercially mature and freshly cut Gerbera jamesonii `Monarck' flowers were placed into clean vases containing deionized water and 0, 2, 5, 10, 20, and 50 μL·L-1 ClO2. Stems were then maintained in solutions at 21 ± 0.5 °C and 42 ± 11% relative humidity until the end of vase life. Inclusion of 2, 5, and 10 μL·L-1 ClO2 in vase water had beneficial effects on flower longevity. For instance, treatment with 5 and 10 μL·L-1 ClO2 extended flower longevity by 1.4-fold or 3.7 days, as compared to control flowers (0 μL·L-1 ClO2). In contrast, exposure to the higher concentrations of 20 and 50 μL·L-1 ClO2 did not extend flower vase life. Relative to control flowers, treatment with 10 μL·L-1 ClO2 delayed the onset of detectable bacterial colonization of vase solutions from day 3 to day 6 of vase life. However, this ClO2 treatment did not reduce the number of bacteria that subsequently accumulated in vase water as compared to control flowers. Treatment with 10 μL·L-1 ClO2 also increased rates of solution uptake by stems and reduced the loss of flower fresh weight over time. These results highlight the potential use of ClO2 treatments to extend the postharvest longevity of Gerbera flowers.

ROSE VASE LIFE: CULTIVAR AND CONTAMINATION SOURCE AS CRITICAL FACTORS

Variation in cut rose vase life was investigated with regards to cultivar and contamination source. Three cultivars that were used were regarded by industry as long-lived ('Cream Prophyta', 'Golden Gate' and 'Royal Prophyta') and the other cultivars that were used were regarded as short-lived ('Aurora', 'Pailine' and 'Snowy Jewel'). Pseudomonas fluorescens was used to contaminate vase water, secateurs, vase surface, and combinations of these treatments to explore the effect of contamination source on the vase life of 'Golden Gate' and 'Snowy Jewel'. The contamination of secateurs was the least detrimental treatment ('Golden Gate' and 'Snowy Jewel') and contamination dried onto the vase surface was the most detrimental single treatment for 'Golden Gate'. Apart from the contaminated secateurs treatment the vase life of 'Snowy Jewel' was reduced in a uniform way by each treatment, 'Snowy Jewel' reacted in an 'all or nothing' manner once a contamination level had been breached; this was not the case for 'Golden Gate'.

Wound-induced and bacteria-induced xylem blockage in roses, Astilbe, and Viburnum

We previously concluded that the xylem blockage that prevents water uptake into several cut flowers is mainly due to the presence of bacteria, whilst in chrysanthemum and Bouvardia we observed a xylem occlusion that was mainly due to a wound-reaction of the plant. We have further tested which of these two mechanisms was dominant in Astilbe,Viburnum and rose flowers. Astilbe x arendsii (cvs. Erica and Glut) flowers were stored dry in plastic bags (24 h at 5 °C, 100% RH) and placed in water at 20 °C without recutting the stems. The dry storage treatment considerably hastened a wounding-induced xylem occlusion in the stems. A 5 h pulse treatment with inhibitors of peroxidase (hydroquinone) and catechol oxidase (tropolone and 2,3-dihydroxynaphtalene), prior to dry storage, considerably delayed the xylem blockage. The 24 h dry storage treatment had no effect in rose ( Rosa x hybrida cv. Red One), and Viburnum opulus (cv. Roseum). These flowers were therefore directly placed in water, with and without enzyme inhibitors. Except hydroquinone, all tested enzyme inhibitors reduced bacterial growth in the vase water. The latter chemicals could therefore not be used to distinguish between a plant-induced and a bacterial occlusion of the xylem. Hydroquinone had no effect on the time to wilting in roses, nor in Viburnum. It considerably delayed wilting in Astilbe flowers that were directly placed in water after harvest. It is concluded that the blockage in Astilbe is mainly due to the plant-induced xylem occlusion. The xylem occlusion in the tested rose and Viburnum cultivar was apparently not due to this mechanism.

Wound-induced and bacteria-induced xylem blockage in roses, Astilbe, and Viburnum

We previously concluded that the xylem blockage that prevents water uptake into several cut flowers is mainly due to the presence of bacteria, whilst in chrysanthemum and Bouvardia we observed a xylem occlusion that was mainly due to a wound-reaction of the plant. We have further tested which of these two mechanisms was dominant in Astilbe,Viburnum and rose flowers. Astilbe x arendsii (cvs. Erica and Glut) flowers were stored dry in plastic bags (24 h at 5 degreesC, 100% RH) and placed in water at 20 degreesC without recutting the steins. The dry storage treatment considerably hastened a wounding-induced xylem occlusion in the stems. A 5 h pulse treatment with inhibitors of peroxidase (hydroquinone) and catechol oxidase (tropolone and 2,3-dihydroxynaphtalene), prior to dry storage, considerably delayed the xylem blockage. The 24 h dry storage treatment had no effect in rose (Rosa x hybrida cv. Red One), and Viburnum opulus (cv. Roseum). These flowers were therefore directly placed in water, with and without enzyme inhibitors. Except hydroquinone, all tested enzyme inhibitors reduced bacterial growth in the vase water. The latter chemicals could therefore not be used to distinguish between a plant-induced and a bacterial occlusion of the xylem. Hydroquinone had no effect on the time to wilting in roses, nor in Viburnum. It considerably delayed wilting in Astilbe flowers that were directly placed in water after harvest. It is concluded that the blockage in Astilbe is mainly due to the plant-induced xylem occlusion. The xylem occlusion in the tested rose and Viburnum cultivar was apparently not due to this mechanism. (C) 2004 Elsevier B.V. All rights reserved.

Daffodil flowers delay senescence in cut Iris flowers

Visible symptoms of tepal senescence in cut Iris × hollandica (cv. Blue Magic) flowers were delayed by placing one cut daffodil flower ( Narcissus pseudonarcissus, cv. Carlton) in the same vase. Addition of mucilage, exuded by daffodil stems, to the vase water had the same effect as the flowering daffodil stem. The active compound in the mucilage was identified as narciclasine (using LC/MS, GC/MS, 1H and 13C-NMR, and comparison with an authentic sample of narciclasine). The delay of senescence, either by mucilage or purified narciclasine, was correlated with a delayed increase in protease activity, and with a considerable reduction of maximum protease activity. Narciclasine did not affect in vitro protease activity, but is known to inhibit protein synthesis at the ribosomal level. Its effects on senescence and protease activity were similar to those of cycloheximide (CHX), another inhibitor of protein synthesis, but the effective narciclasine concentration was about 100 times lower than that of CHX. It is concluded that the delay of Iris tepal senescence by daffodil stems is due to narciclasine in daffodil mucilage, which apparently inhibits the synthesis of proteins involved in senescence.

Embolism in rose stems as a result of vascular occlusion by bacteria

Abstract Using detection of ultrasonic acoustic emissions (UAE), we tested the hypothesis that xylem blockage by bacteria in rose stems ( Rosa hybrida L.) can induce cavitation. In both Madelon and Cara Mia roses, cavitation started when the bacterial count in vase water reached 10 8 ml −1 , although the number of cavitations was higher in Cara Mia stems. Following placement in water containing 10 8 colony forming units (cfu) of bacteria, cavitation occurred immediately, both in Madelon and Cara Mia roses. After removal of the conduits that were opened at harvest (by recutting 25 cm of the stem end under water), prior to placement in the bacterial suspension, no cavitations were observed in stems of Madelon roses. This indicated that cavitation started with the air in xylem conduits that were opened by cutting. In contrast, recutting 25 cm under water from the stems of Cara Mia roses did not reduce the number of cavitations. It is concluded that a bacterial occlusion resulted in a high rate of cavitation, hence in a considerable number of conduits, with air bubbles. These bubbles may further impede water uptake.

Effect of aminooxyacetic acid and sugars on the vase life of Dendrobium flowers

We investigated the effect of sugars and aminooxyacetic acid (AOA) on Dendrobium ‘Jew Yuay Tew’ inflorescences bearing open flowers and flower buds. Glucose or sucrose in the vase water had no effect on vase life. AOA alone also did not improve vase life, but AOA together with sugars considerably increased it. The treatment suppressed bud drop, promoted bud opening, and delayed the time to senescence of open flowers. Its effect was counteracted by raising solution pH (which was 3.2) to 4.2 or higher. Bacterial counts in the vase solution were low at pH 3.2, but increased when the pH was raised. The pH of 0.5 mM AOA alone was initially about 3.0, but started to increase by day 8 of vase life and had reached pH 5 by day 12. When 4% glucose was added to this solution, the pH remained around 3 until day 20 of vase life. The combination of 0.5 mM AOA and glucose thus allows continuous uptake of water and dissolved sugars by the flower. It is concluded that the vase life of Dendrobium ‘Jew Yuay Tew’ flowers is limited by adverse water relations and can be improved by sugars if water uptake is maintained. # 2003 Elsevier Science B.V. All rights reserved.

Embolism repair in cut flower stems: a physical approach

The role of xylem anatomical properties on air embolism removal and xylem hydraulic conductance recovery from cut flower stems during the first hours of vase life was studied from a physical point of view. A model based on physical processes was developed and tested using chrysanthemum ( Dendranthema × grandiflorum Tzvelev) cut flowers. The model predicts that the repair process takes place in two major phases. During the first few seconds after replacing in water, initially air-filled vessels at the cut surface partly refill with water. Consequently, reconnections are established between the vase water and the non-cut water-filled xylem vessels just above the cut surface and hydraulic conductance is partly recovered. During the following hours, air partly or completely dissolves into the surrounding water in the stem and hydraulic conductance recovery gradually takes place. The results of the model agreed well with dynamic measurements of hydraulic conductance recovery on chrysanthemum stem segments after aspiration of air. Visual detection of air emboli by cryo-scanning electron microscopy showed that after 1.5 h of repair, air was only present in large-diameter vessels at a position relatively distant from the cut surface of the stem. According to the model, hydraulic conductance repair occurs more readily in stems with smaller diameter vessels. Model calculations and experiments showed that the height of water in the vase influences recovery of water uptake more in stems with large-diameter vessels than in stems with small-diameter vessels. It is concluded that the anatomical structure of the xylem plays an important role in the rehydration capability of cut flowers.

Glucose prevents leaf blackening in ‘Sylvia’ proteas

Abstract Cut flowers of Protea cv. Sylvia show severe leaf blackening. Sucrose pulsing and sucrose in holding solutions did not alleviate this problem, and sometimes even promoted leaf blackening. Sucrose concentrations in untreated leaves and flowers increased early on during vase life, followed by a decrease, while glucose and fructose concentrations decreased both in leaves and flowers. Inclusion of 2.5% glucose in the vase water of ‘Sylvia’ proteas increased vase life from 6 days (control) to 20 days.

Reconsideration of the use of deionized water as vase water in postharvest experiments on cut flowers

The relevance of deionized water as a control treatment in vase life experiments and the effects of major tap water components on cut flower water balance were investigated. Chrysanthemum (Dendranthema x grandiflorum Tzvelev cv. Cassa) was used in all experiments. Deionized water gave a sharp decrease in fresh weight of the cut flowers after 1–3 days. This decrease was absent in tap water. After 4 days in deionized water, hydraulic resistance in the basal part of the stem was ∼50 times the value of fresh cut flowers and seven times the value in tap water. Change in fresh weight during vase life in a solution containing combinations of CaCl2, NaHCO3 and Cu2+ at concentrations commonly present in tap water was similar to that in tap water. However, none of the minerals tested by themselves gave fresh weight results similar to those from using tap water. In the combined solution, hydraulic resistance in the basal part of the stem after 4 days was comparable to that in tap water. A minimal amount of Cu2+ (>0.30 mg·l−1) enhanced fresh weight, probably by reducing bacterial growth in the cut open vessels. Calcium chloride (>0.7 mM) delayed the increase in hydraulic resistance in the stem (not including the basal 3 cm) compared to deionized water, and at a high concentration (10.7 mM), substantially decreased the transpiration rate. Sodium bicarbonate (1.5 mM) neither affected hydraulic resistance nor transpiration rate, but positively influenced fresh weight change during vase life when combined with CuSO4 and as compared to deionized water. Results strongly question the appropriateness of deionized water as a control solution in vase life experiments.

Reconsideration of the use of deionized water as vase water in postharvest experiments on cut flowers

Abstract The relevance of deionized water as a control treatment in vase life experiments and the effects of major tap water components on cut flower water balance were investigated. Chrysanthemum ( Dendranthema x grandiflorum Tzvelev cv. Cassa) was used in all experiments. Deionized water gave a sharp decrease in fresh weight of the cut flowers after 1–3 days. This decrease was absent in tap water. After 4 days in deionized water, hydraulic resistance in the basal part of the stem was ∼50 times the value of fresh cut flowers and seven times the value in tap water. Change in fresh weight during vase life in a solution containing combinations of CaCl 2 , NaHCO 3 and Cu 2+ at concentrations commonly present in tap water was similar to that in tap water. However, none of the minerals tested by themselves gave fresh weight results similar to those from using tap water. In the combined solution, hydraulic resistance in the basal part of the stem after 4 days was comparable to that in tap water. A minimal amount of Cu 2+ (>0.30 mg·l −1 ) enhanced fresh weight, probably by reducing bacterial growth in the cut open vessels. Calcium chloride (>0.7 mM) delayed the increase in hydraulic resistance in the stem (not including the basal 3 cm) compared to deionized water, and at a high concentration (10.7 mM), substantially decreased the transpiration rate. Sodium bicarbonate (1.5 mM) neither affected hydraulic resistance nor transpiration rate, but positively influenced fresh weight change during vase life when combined with CuSO 4 and as compared to deionized water. Results strongly question the appropriateness of deionized water as a control solution in vase life experiments.