Increased Vase Life Research Articles

EFFECTS OF SILVER THIOSULFATE TREATMENT ON POSTHARVEST LIFE OF CUT LISIANTHUS FLOWERS

The effects of postharvest silver thiosulfate (STS) treatments on physicochemical characteristics of four cut lisianthus (Eustoma grandiflorum) cultivars ('Purple', 'White', 'Purple-Rim' and 'Pink-Rim') were investigated. Cut lisianthus flowers were pulse-treated with silver thiosulfate at 0, 0.5, 1 and 2 mM and for 24h at 22±2°C. The experiment was conducted in completely randomized designs with factorial arrangement and seven replications. The results of the experiment revealed that STS at all concentrations applied significantly (P>0.05) extended vase life of all cut lisianthus flowers compared to the control. No significant differences were found between STS concentrations in 'Purple', 'White' and 'Pink-Rim'. However, in 'Purple-Rim', STS at 1 and 2 mM significantly increased vase life of flowers compared to 0.5 mM STS treated flowers (Table 1). There were significant differences between cultivars in response to STS concentrations too. STS treated flowers at all concentrations maintained a higher relative fresh weight (RFW) in all cultivars. Solution uptake of STS treated flowers was more than control during the whole experiment.

RESPONSES OF MOKARA 'NORA PINK' INFLORESCENCES TO BIOCIDE IN VASE SOLUTION

The major problem of cut orchid inflorescence is floret wilting or dropping. Therefore, the objective of this research was to study the effects of sugar and biocide on postharvest quality of Mokara 'Nora Pink' inflorescence. Inflorescences were harvested in June 2009 at the commercial maturity stage with 6-7 open flowers and 4-5 bud flowers, then stem of individual inflorescences were re-cut and put in 15 ml centrifuge tube containing distilled water (control), 20 mg.L -1 DICA+ 2% sucrose, 40 mg.L -1 DICA + 2% sucrose, 20 mg.L -1 DICA and 40 mg.L -1 DICA. All inflorescences were placed at 25°C, 60% RH under fluorescence light. The data were recorded at daily interval. The relative fresh weight was declined throughout the experiment. Inflorescences kept in 40 mg.L -1 of DICA had the highest fresh weight and water uptake. There were no differences in bud opening and flower drop among the treatments. DICA at 40 mg.L -1 significantly reduced total microorganisms in vase solution and increased vase life about 5 days compared to that of control.

Treatment with thidiazuron improves opening and vase life of iris flowers

The marketability of Dutch iris ( Iris × hollandica) cut flowers is limited by their short display life and frequent failure to open fully. We tested the ability of thidiazuron (TDZ), a phenyl-urea compound with cytokinin-like activity, to improve iris flower opening and longevity. A postharvest pulse with 0.2–1 mM TDZ for 6–24 h at 0 or 20 °C extended the vase life of flowers by up to 1.5 d relative to control (0 mM TDZ) stems in water. TDZ treatment also stimulated growth of the pedicel and ovary by up to 2.5 cm that, in turn, led to more complete opening of flowers. Inclusion of 1 mM gibberellic acid (GA 3) in the TDZ pulsing solution did not extend vase life further but did increase flower shoot elongation by an additional 1.0 cm. Provision of 20% sucrose with the TDZ plus GA 3 treatment had an additive effect, increasing vase life and shoot growth by a further 0.8 d and 1.0 cm, respectively. Pulsing stems with this combined treatment prior to storing flowers dry for 14 d at 0 °C provided maximum flower opening and display life after storage. Treatment with 0.5 mM TDZ stimulated a significant increase in ethylene production by flowers during their opening.

Effects of plant growth regulators and sucrose on post harvest physiology, membrane stability and vase life of cut spikes of gladiolus

Effects of post-harvest application of two plant growth regulators viz., gibberellic acid (GA3) and benzyl adenine (BA) with sucrose in the vase solution on cell membrane stability and vase life of gladiolus were investigated. The vase solution treatment combinations of GA3 and BA with sucrose significantly increased the membrane stability index and enhanced the vase life as compared to the sucrose alone treatments or the controls. Vase solution treatment of GA3 (50 mg l−1), followed by BA (50 mg l−1) with sucrose (50 g l−1) significantly increased solution uptake, fresh weight and dry weight of cut spikes. The same treatments also enhanced the concentration of reducing and non-reducing sugars in gladioli petals 4 days after treatment (DAT). Cut spikes in vase solution enriched with 50 mg l−1 GA3 + 50 g l−1 sucrose showed higher antioxidative enzyme activities of superoxide dismutase (SOD) and glutathione reductase (GR), lower lipoxygenase (LOX) activity and lipid peroxidation (measured as TBARS). Petal membrane stability index was also highest in cut spikes 6 DAT with 50 mg l−1 GA3 + 50 g l−1 sucrose vase solution. Treatment of gladiolus cut spikes with 50 mg l−1 GA3 + 50 g l−1 sucrose vase solution showed two fold increase in vase life and improved flower quality with a higher number of open flower per spike at any one time. These results suggest that post-harvest application of GA3 (50 mg l−1) with sucrose (50 g l−1) maintains higher spike fresh and dry weight, improves anti-oxidative defence, stabilizes membrane integrity leading to a delay in petal cell death.

PHYSIOLOGICAL CHANGE ASSOCIATED WITH TUBEROSE CUT FLOWERS SENESCENCE IN RESPONSE TO ANTI ETHYLENE AND HOLDING SOLUTIONS

Various postharvest treatments were evaluated for their effect on longevity and quality of cut Polianthus tuberose cv. Double, spikes which were harvested when the basal 4 flowers were opened. Spikes were pulsed in silver thiosulfate (STS) 1:4 mM, for 10 minutes at 24 °C. They were treated for 24 hours at 24°C with control (without treatment), 10 and 100 nI/L1 1-MCP. The flowers were stored for 0,3 and 5 days at 5°C then were placed in jars of a holding solution (500 ml) containing 30 g/I sucrose, 200 mg/I 8- hydroxyquinoline dtrate and 150 mg/I citric acid until the end of experiment. The results indicated that all pretreatments increased vase life compared with the control. The highest percentage of fully opened florets, fresh weight and water uptake were obtained in 100 WU' 1-MCP compared with the other treatments. The life of the flowers was significantly increased by inhibiting ethylene action using pretreatinent with either 1-MCP or silver thiosulfate (STS). 1-MCP was more effective than STS in maintaining flower quality. Increasing storage duration from 3 up to 5 days decreased vase life and flower quality. The flowers pretreated with 1-MCP at 100 n1/1:I then stored for 0 or 3 days produced the highest longevity and flower quality.

Methyl jasmonate vapour treatment suppresses specking caused by Botrytis cinerea on cut Freesia hybrida L. flowers

Treatment of cut freesia var. Cote d’Azur flowers with methyl jasmonate (MeJA, 0.1 μl MeJA l −1) vapour suppressed petal specking caused by Botrytis cinerea infection. MeJA efficacy was concentration and incubation temperature dependent. Disease severity, lesion numbers and lesion diameters decreased with increasing MeJA concentration from 0.025 to 0.1 μl MeJA l −1. However, there were no significant ( P > 0.05) differences among MeJA concentrations examined. MeJA was more effective in reducing B. cinerea flower specking at 20 °C than at 12 °C. MeJA treatment was ineffective at 5 °C. At 20 °C, MeJA treatment at 0.1 μl MeJA l −1 reduced disease severity, lesion numbers and lesion diameters by 58, 50 and 48%, respectively, as compared to untreated controls. In a repeat experiment, disease severity, lesion numbers and lesion diameters on MeJA vapour treated flowers after 12 h of incubation were reduced by 68, 56 and 50%, respectively. MeJA did not exert direct antifungal activity in-vitro, suggesting that treatment in-vivo reduced B. cinerea-induced flower specking by induction of host defence responses. MeJA at 0.1 μl MeJA l −1 significantly ( P < 0.05) increased vase life of cut freesia flowers and delayed senescence judged by lower wilt scores and higher fresh weights as compared to untreated controls.

Post harvest Handling of Cut Linaria, Trachelium, and Zinnia

Optimum postharvest handling procedures were determined for Linaria maroccana `Lace Violet', Trachelium`Jemmy Royal Purple', and Zinnia elegans `Benary's Giant Scarlet' and `Sungold.' A 24-hour 10% or 20% sucrose pulse increased the vase life of Linaria by 2–4 days, resulting in a vase life of 9 days as compared to 5 days for control flowers held in deionized (DI) water. Use of floral foam and cold storage at 1 °C for 1 week decreased vase life. Treatment with either 0.1 or 1.0 ppm ethylene had no effect. The use of a commercial holding solution (Floralife Professional or Chrysal Professional 2 Processing Solution) or 2% or 3% sucrose increased vase life 4–10 days. For cut Trachelium, ethylene caused florets to close entirely or stop opening; 1-MCP and STS prevented these ethylene effects. Stems tolerated 4 days of 1 °C storage, but 1 week or more of storage reduced the 14-day vase life of unstored flowers to 9 days. Stems in 2% or 4% sucrose had a longer vase life compared to DI water. While the use of floral foam was not detrimental when used with sucrose solutions, it reduced vase life when sucrose was not used. Zinnia stems could not be cold stored for 1 week at 1 °C due to loss of turgidity and cold damage. Stems stored dry at 5 °C regained turgidity and averaged a vase life of 14 days; however, petals remained slightly twisted and curled after being in the vase for several days. Treatment with ethylene had no effect. Floral foam reduced vase life to 9–10 days.

ROLE OF ETHYLENE IN OVARY GROWTH AND VASE LIFE OF DENDROBIUM ´POMPADOUR´ FLOWERS

We studied the role of ethylene and sugar (sucrose) supply in ovary growth of Dendrobium 'Pompadour'. Ethylene synthesis was inhibited using aminooxyacetic acid (AOA). Sucrose was supplied in a holding solution also containing two antimicrobial compounds (8-hydroxyquinoline sulfate and silver nitrate). Control flowers were left unpollinated. Ovary growth only occurred after pollination, and was completely suppressed by AOA treatment. AOA was not toxic in unpollinated control flowers. Sucrose (5%) with the holding solution had no effect on ovary growth. Preliminary experiments with pollinated Dendrobium Sonia Bom # 28 flowers also showed complete suppression of ovary growth by AOA, whilst ovary growth was stimulated following treatment with exogenous ethylene. Flower wilting was the main determinant of the length of vase life; from day 8 some flowers also started to fall. In unpollinated flowers, AOA delayed the time to wilting of 50% of the flowers, but did not affect the time to flower abscission. Sucrose increased vase life of unpollinated orchid flowers by delaying wilting and a suppressing flower abscission. In contrast, the sucrose solution did not affect the (much shorter) vase life of pollinated flowers. In contrast to unpollinated climacteric flowers, like carnation, where sugars reduce sensitivity to endogenously produced ethylene, such a decrease in sensitivity apparently does not occur in pollinated Dendrobium flowers.

GETTING THE BEST FROM THE BUSH - FACTORS AFFECTING POSTHARVEST QUALITY OF PINK WAXFLOWER (ERIOSTEMON AUSTRALASIUS) AND NSW CHRISTMAS BUSH (CERATOPETALUM GUMMIFERUM)

Marketing of many Australian native cut flowers is limited by their variability and short vase life. The effect of pre-harvest factors on postharvest quality of such floral crops is generally poorly understood. We have examined some of the factors affecting vase life of pink waxflower (Eriostemon australasius) and NSW Christmas bush (Ceratopetalum gummiferum). Vase life varied significantly between Eriostemon varieties and was increased by harvesting at the bud stage instead of at commercial maturity (50% open). Protected cropping of NSW Christmas bush could increase vase life relative to field grown material, but results were not consistent for all locations. Larger NSW Christmas bush Stems had significantly longer vase lives than smaller pieces. Differences in vase life between the largest (>40g) and smallest (<20g) stems were increased when the material was stored for 12 days at 5°C. Although large diameter stems took up the most water in total, small diameter stems took up more water per gram fresh weight. This suggests that stem conductance is not a limiting factor, but that loss of carbohydrates may contribute to premature senescence in NSW Christmas bush.

Ethylene and anti-ethylene treatment effects on cut 'First Red' rose.

Studies were conducted to determine the effects of ethylene and anti-ethylene treatments on postharvest life of cut First Red rose flowers. Effects of exogenous ethylene at 1, 10 and 100 ul l-1 for 48 h at 22 C on cut First Red rose flowers were investigated. Ethylene at different concentrations reduced postharvest life, with 100 ul l-1 having the greatest effect. Ethylene production measurements suggested that First Red rose is climacteric during senescence. Pre-treatment of First Red rose flowers with 0.5 mM silver thiosulfate (STS) for 2 h at 22 C increased vase life, but pre-treatment with 1 ul l-1 1- methylcyclopropene (1-MCP) did not. Pre-treatment of First Red rose with 0.5 mM STS and, to a lesser extent, 1 ul l-1 1-MCP for 2 h at 22 C, protected flowers from subsequent exposure to 10 ul l-1 ethylene. Maximum vase life in both ethylene-treated and non-ethylene-treated First Red rose flowers was obtained with 0.5 mM STS.

COMPARISON OF SILVER THIOSULFATE WITH 1-METHYLCYCLOPROPENE ON 19 CUT FLOWER TAXA

The effects of silver thiosulfate (STS; AVB) and 1-methylcyclopropene (1-MCP; Ethylbloc) were determined on 14 commonly-grown cut flower species, represented by one to three cultivars per species. Stems were unpacked, sorted, and placed in either deionized water (DI) and subjected to 1-MCP (740 nL L') or ambient air for 4 h or DI plus STS at either 0.1 mM (Alstroemeria) or 0.2 mM (all other species) for 4 h. After treatment, stems were removed, placed in polyethylene sleeves and stored either wet in DI water or dry in plastic-lined floral boxes at 5°C in the dark for 4 days. After storage bunches were placed in DI water under 12 h (76 to 100 μmol m -2 s -1 ) light per day. Flowers were monitored daily to determine the end of wholesale vase life, which was designated as the first day a change was noticed in the flower or inflorescence that would typically prevent it from being sold by a wholesaler or retailer. The consumer vase life was also recorded for each stem and was designated as the day a typical consumer would dispose of it. The 19 cut flower taxa could be organized into four groups based on effectiveness of STS and 1-MCP: (1) Both STS and 1-MCP increased vase life but STS was more effective: Dianthus caryophyllus (all three cultivars), Bouvardia, Lilium (Asiatic), and Lathyrus odorata. (2) Both STS and 1-MCP prevented the negative effects of dry storage: Freesia (both cultivars) and Chamelaucium (one cultivar). (3) STS increased vase life while 1-MCP did not: Alstroemeria, Delphinium, Matthiola, and Gypsophila. (4) STS and 1-MCP either had no effect or a negative effect: Consolida, Eustoma, Ranunculus, Antirrhinum, and Chamelaucium (one cultivar).

STORAGE AND SIMULATED SHIPPING OF CUT ´RENAISSANCE RED´ POINSETTIAS

The effect of several storage and handling treatments on the vase life of cut ‘Renaissance Red’ poinsettia (Euphorbia pulcherrima) stems was investigated. Removing all foliage increased vase life and delayed cyathia abscission. Stems with 100% of foliage (9 to 11 leaves) had fewer days to first abscised leaf than stems with 50% foliage (5 leaves) remaining. Allowing cut stems to dehydrate for 24 h at 20 o C caused the inflorescences to wilt severely and allowed them to be more easily packed in a box. However, wilting reduced vase life and hastened leaf abscission, but had no effect on cyathia abscission. Cut stems tolerated 12 or 24 h dry storage at 1 or 5 o C with no decrease in vase life which averaged 24.5 to 28.2 days in deionized (DI) water. Storing cut stems wet at 1 or 5 o C for 12 or 24 h reduced vase life to 13.3 to 20.2 days. Storage for 48 h at 1 or 5 o C either wet or dry reduced vase life compared to 12 or 24 h storage. Increasing storage duration decreased the number of days to first leaf and cyathia abscission, regardless of storage conditions. Light during 10 o C long term storage had no effect on vase life or days to first cyathia or leaf abscission.

EFFECTS OF GIBBERELLIC ACID ON THE VASE LIFE OF CUT PATUMMA (CURCUMA ALISMATIFOLIA GAGNEP.) 'CHAING MAI' FLOWERS

Cutflowers of Patumma (Curcuma alismatifolia Gagnep.) ‘Chaing Mai’ were held in 50-200 ppm gibberellic acid (GA3) or distilled water (control) at 25°C with 75-80% relative humidity. GA3 at 100 ppm increased vase life by four days compared to the control (10 days). Increasing the concentration to 150-200 ppm did not correspondingly extend vase life despite improvement in weight retention, absorption capacity and water conductivity of stem tissues. The vase life of the flower held in 150-200 ppm GA3 was similar to that with 100 ppm GA3. GA3 did not generally affect respiration rate but significantly reduced ethylene production. At lower concentration of 50 ppm GA3, responses of the flowers were comparable to the control.

PHYSIOLOGICAL CHANGES DURING POSTHARVEST LIFE OF CUT SUNFLOWERS

The vase life of sunflowers (Helianthus annuus) is limited by early wilting of leaves and ray flowers. Vase life was positively correlated with stem length (5 days in 50 cm stems, 9 days in 70 cm stems). We also studied the vase life after a 24 h pulse treatment with a number of chemicals. It was significantly increased by treatment with 150 mg L -1 citric acid. Treatment with 10 µl L -1 ethylene reduced vase life and induced both flower bending and abscission of ray flowers. In contrast, 2 mM amino-oxyacetic acid (AOA), an ethylene inhibitor, reduced ethylene production but did not increase vase life. 8-Hydroxyquinoline (8-HQS) at 150 mg L -1 did not lengthen vase life. Vase life was reduced by treatment with 2% sucrose combined with either 150 mg L -1 citric or with 150 mg L -1 8-HQS.

Effects of Tea-Seed Saponins on the Vase Life, Hydraulic Conductance and Transpiration of Cut Rose Flowers

Saponin(s) was extracted from tea seeds, and its effect on the vase life, transpiration from leaves and hydraulic conductance of stem segments in cut roses (Rosa hybrida L. cv. Sonia) were investigated. The continuous treatment with tea-seed saponins (TSS) at 20 mg L-1 significantly extended the vase life of cut rose flowers, but those at other concentrations did not. The volume of water uptake and water loss by the cut flowers decreased with increasing concentration of TSS. TSS induced stomatal closure. In cut flowers kept in water, hydraulic conductance of the stem segment decreased with time,and 20 mg L-1 TSS treatment considerably suppressed this decrease. The results show that TSS markedly inhibited transpiration from leaves and suppressed decrease in hydraulic conductance, which may be responsible for a significant increase in vase life.

Optimizing Postharvest Life of Cut `Renaissance Red' Poinsettias

Several treatments were investigated for increasing vase life of cut `Renaissance Red' poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch.) stems. A vase life of at least 20.6 days resulted when harvested stems were placed directly into vases with 22 °C deionized water plus 200 mg·L-1 8-HQS (the standard floral solution used) and 0% to 1% sucrose without floral foam. Maturity of stems at harvest, ranging from 0 to 4 weeks after anthesis, had no effect on vase life or days to first abscised leaf. Pretreatments immediately after harvest using floral solution heated to 38 or 100 °C, or 1 or 10-min dips in isopropyl alcohol, had no effect, whereas 24 hours in 10% sucrose shortened vase life by 6.4 days and time to first abscised cyathium by 4.5 days. Stem storage at 10 °C decreased vase life, particularly when stems were stored dry (with only 0.8 days vase life after 3 weeks dry storage). Increasing duration of wet storage in floral solution from 0 to 3 weeks decreased vase life from 21.5 to 14.6 days. Placing cut stems in a vase containing floral foam decreased time to first abscised leaf by 3.7 to 11.6 days compared with no foam. A 1% to 2% sucrose concentration in the vase solution produced the longest postharvest life for stems placed in foam but had little effect on stems not placed in foam. A 4% sucrose concentration decreased vase life compared with lower sucrose concentrations regardless of the presence of foam. Holding stems in the standard floral solution increased vase life and delayed leaf abscission compared with deionized or tap water only, with further improvement when stem bases were recut every three days. Commercial floral pretreatments and holding solutions had no effect on vase life and days to first abscised cyathium but delayed leaf abscission.

Pre-harvest calcium sulfate applications affect vase life and severity of gray mold in cut roses

Gray mold, caused by Botrytis cinerea Pers. Fr., is a major disease in roses. The effect of spraying rose (Cultivar ‘Kiss’) buds with calcium sulfate on the intensity of gray mold was evaluated. Calcium sulfate was sprayed on the buds at different schedules and concentrations before harvest. Thereafter, the buds were harvested and either inoculated or not with B. cinerea. The treatments reduced both the progress and severity of gray mold and increased vase life of the flowers. Good results were achieved with 10 and 20 mM calcium sulfate, applied 24 h before harvest. In the uninoculated assay, the maximum percentages of reduction of the area under the disease progress curve (AUDPC) and of severity were 86% and 86%, respectively, and in the inoculated assay, 68% and 76%, respectively. Vase life of the flowers was increased at least 30% in the assay without inoculation and 20% in the assay with inoculation. Spraying roses with calcium sulfate at 10 mM or 20 mM one day before harvest is recommended to control gray mold after harvest.

Effects of vase solution pH and abscisic acid on the longevity of cut ‘Baccara’ roses

SummaryAbscisic acid (ABA) supplied in the vase solution can induce stomatal closure in the leaves of cut flowers, including roses (Rosa hybrida L.).This effect may be beneficial in reducing water deficit stress. Extracellular pH can affect active ABA concentrations in the apoplast of guard cells, with sap alkalisation enhancing the physiological activity of ABA. Accordingly, it was hypothesized that vase solution pH may affect ABA-mediated stomatal closure of cut roses. Two experiments were conducted to study the interaction of vase solution pH and ABA. In the first, cut ‘Baccara’ roses were held in vase solutions with ± l0–5 M ABA at pH 6, pH 7 and pH 8. In the second experiment, roses were held with ± 10–5 M ABA at pH 6 and pH 8 in the presence and absence of 1 mg l–1 AgNO3 as a bactericide. Supply of ABA increased vase life and reduced vase solution usage of flowers held in low pH 6 solutions, indicating induction of stomatal closure. Conversely, ABA supplied at pH 8 was associated with reduced vase life. This negative result was associated with enhanced development of vase solution microbes at high pH, which overrode any potential pH-mediated ABA efficacy effects.

Gray mold severity and vase life of rose buds after pulsing with citric acid, salicylic acid, calcium sulfate, sucrose and silver thiosulfate

Gray mold of roses (Rosa hibrida) caused by Botrytis cinerea requires many management strategies for its control. The effect of pulsing rose cv. Kiss with solutions of citric acid, salicylic acid, sucrose, calcium sulfate, and silver thiosulfate (STS) on disease severity and vase life of the flowers was evaluated. The solutions were applied to cut stems at different stages of harvest, the variation in the opening stage of harvest did not affect the results. Pulsing with STS reduced the values of area under the disease progress curve (AUDPC) and of severity of disease by 15% and 55%, respectively, and increased the vase life of the flowers by 20%. Calcium sulfate consistently reduced AUDPC by 66% and maximum severity by 88%, and increased vase life of the flowers by 37%. Therefore, pulsing rose buds with solutions of STS and calcium sulfate is potentially useful in reducing losses due to gray mold after harvest and in extending the vase life.

Abscisic acid analogue effects on the vase life and leaf crisping of cut Baccara roses

The plant growth regulator abscisic acid induces stomatal closure, which can reduce transpiration rate and extend vase life of cut flowers by maintaining a positive water balance. Analytical-reagent grade abscisic acid is, however, expensive. In this work, the effects of 2 potentially inexpensive synthetic analogues of abscisic acid were studied as to their effects on cut Baccara roses. Abscisic acid and its analogues PBI-365 and PBI-429 reduced transpiration and helped to increase fresh weight during the first few days of vase life. However, the reduction in transpiration rate brought about by abscisic acid and the analogues did not alter vase life. Sucrose in the vase solution at concentrations of 2 and 4% increased vase life of cut Baccara roses. However, the highest sucrose concentration (4%) caused leaf crisping, thereby reducing the quality of the flower stems. Abscisic acid and the analogue PBI-365 reduced this phytotoxicity by induction of stomatal closure and reduction of vase solution sucrose flux into the leaves.