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Lisianthus is among the most popular cut flowers. Regarding the postharvest losses, these experiments were designed to compare the effects of a nanosilver (NS) based preservative to the standard preservative containing 8-hydroxyquinoline citrate (8-HQC) and sucrose (S). Additionally, the effect of 24 h conditioning in the NS solution on the postharvest longevity and the general condition of lisianthus (Eustoma grandiflorum ‘Mariachi Blue’) was tested. The vase life of flowers on conditioned and non-conditioned stems was extended by the preservatives, more so by NS + S than by 8-HQC + S (44–54% versus 13–23%). Conditioning had no detectable effect on longevity. Daily water uptake showed alternative peaks and drops, with a general tendency of the uptake rate to decrease over time. The highest uptake intensity and the highest transpiration rate were in stems in the NS + S solution while the lowest was in 8-HQC + S. Conditioning negatively affected the average fresh weight of the flowering stems in all holding solutions with stems in preservatives being heavier than those in water. Preservatives did not induce accumulation of the total soluble or reducing sugars in petals; such accumulation was promoted by conditioning, but only in the upper flowers. The free proline content increased in senescing lower flowers on non-conditioned stems; conditioning limited this increase in flowers in preservatives. In the upper flowers, free proline increased in both water controls while the preservatives and conditioning generally reduced the proline contents below the initial level. Conditioning lowered the hydrogen peroxide contents in senescing lower flowers, relative to the initial level and the non-conditioned stems. The catalase activity kept dropping during the vase life in both the lower and upper flowers, in conditioned and non-conditioned stems, with the exception of flowers from water where the activity remained the highest from all three treatments. It appears that the NS preservative with sucrose improves the overall condition of lisianthus flowers and extends their vase life.

We studied the role of ethylene control in regulating energy metabolism, antioxidant enzyme activity, and vase life of cut rose Rosa hybrida ‘Carola’. Rose flowers at stage II were sprayed with one of the following solutions: water (control), 10 μL L−1 1-methylcyclopropene (1-MCP), or 0.5 g L−1 2-chloroethanephosphonic acid (ethephon). After harvest, ethylene production rate, respiration intensity, energy charge (EC), activities of energy metabolism-related and antioxidant enzymes, and malondialdehyde (MDA) content were measured. Results showed that 1-MCP enhanced the activities of superoxide dismutase, H+-adenosine triphosphatase, Ca2+-adenosine triphosphatase, succinic dehydrogenase, and cytochrome c oxidase, increased adenosine triphosphate (ATP) content, maintained high EC levels, inhibited respiration intensity, reduced peroxidase (POD) and polyphenol oxidase (PPO) activity and MDA accumulation, and prolonged vase life. Ethephon promoted ethylene production and respiration intensity, increased POD and PPO activity, reduced ATP content and EC levels, and accelerated senescence. Our results support a novel role for ethylene control in regulating senescence of ‘Carola’.

Vase life of 'Karma Thalia' dahlia (Dahlia xhybrida), 'Lace Violet' linaria (Linaria maroccana), 'Sunrise' lupine (Lupinus hartwegii ssp. cruickshankii), 'Temptress' poppy (Papaver nudicaule), 'Indian Summer' rudbeckia (Rudbeckia xhybrida), 'Jemmy Royal Purple' trachelium (Trachelium caeruleum), and 'Benary's Giant Scarlet' and 'Sun Gold' zinnias (Zinnia elegans) was determined after being subjected to postharvest handling procedures. Cut dahlia, lupine, poppy, rudbeckia, trachelium, and 'Sun Gold' and 'Benary's Giant Scarlet' zinnia flowers could be held in unamended tap or deionized (DI) water with no effect on vase life. Vase life of linaria was longest when placed in DI water with 8-hydroxyquinoline citrate and a solution pH of 3.5. A vase solution of 2% sucrose without foam extended consumer vase lives for linaria, trachelium, and 'Benary's Giant Scarlet' zinnia. Floral foam or 2% or 4% sucrose had no effect on the consumer vase life of dahlia, lupine, rudbeckia, and poppy. Trachelium and rudbeckia did not tolerate a 20% sucrose treatment for 24 h, whereas linaria and 'Benary's Giant Scarlet' zinnia had a longer vase life with a 10% sucrose pulse than a water-only pulse. For trachelium, the longest (17.5 days) consumer vase life occurred when the Chrysal Professional 2 Processing solution (CP2) was used after pretreatment with DI water. Either of two commercial holding solutions, CP2 or Floralife Professional (FLP), similarly extended the vase life of linaria. The use of FLP or CP2 improved consumer vase life of dahlia, lupine, and poppy compared with DI water. Dahlia, trachelium, and zinnia flowers could not be cold stored at 2 °C. Lupine and poppy could be stored at 2 °C wet or dry for 2 weeks. Linaria and rudbeckia could be cold stored for 3 weeks. Lupine and trachelium were susceptible to 1 μL·L-1 exogenous ethylene, which induced floret abscission in lupine and stopped floret opening in trachelium. 1-Methylcyclopropene and silver thiosulfate similarly suppressed the ethylene effect. Cut linaria, zinnia, dahlia, rudbeckia, and poppy flowers were unaffected by exogenous ethylene.

A protocol for the preparation of preserved flowers retaining natural color and texture of ‘Moondust Velvet Blue’ carnations (Dianthus caryophyllus) was developed. This three-step process consists of soaking flowers in ethyl alcohol, then soaking them in polypropylene glycol, followed by a rinse with ethyl alcohol. Some kinds of flowers processed in this manner retained their natural color and texture for at least 6 months. The physicochemical properties of appropriate solvents used for retaining natural pigmentation and texture are discussed. This protocol is applicable to 13 kinds of flowers among 30 kinds of flowers tested and adds a new dimension to postharvest techniques for cut flowers.

Petal abscission was studied in roses ( Rosa hybridaL.), cvs. Korflapei (trade name Frisco), Sweet Promise (Sonia) and Cara Mia (trade name as officially registered cultivar name). Unlike flowers on plants in greenhouses, cut flowers placed in water in the greenhouse produced visible symptoms of water stress, depending on the weather during the experiment and on the cultivar. Cut Frisco roses showed no visible signs of water stress and the time to petal abscission was as in uncut flowers. In Sonia roses the symptoms of water stress varied from mild to severe, and the number of flowers in which the petals abscised varied from 100% (mild stress) to 0% (severe stress). An antimicrobial compound in the vase water of Sonia roses, or removal of the leaves, alleviated the symptoms of water stress and increased the number of stems in which the petals abscised. Cut Cara Mia roses showed severe symptoms of water stress in all experiments and petal abscission was found in only a few flowers, even when the stems were placed at 20 °C and low photon flux (15 μmol m -2s -1). Abscission in Sonia and Cara Mia roses was low or absent when the water potential of the leaves reached values below -2.0 MPa within the first 5 d of the experiment; such low values were not reached in Frisco roses. Addition of sucrose to the vase solution, together with an effective antimicrobial compound, had no effect on the time to petal abscission, at any light intensity. Placing flowers in far-red light also had no effect on abscission, compared with flowers placed in red light or white light of the same photon fluence. It is concluded that petal abscission in the rose cultivars studied is not affected by their water status unless the plants reach a low water potential (about -2 MPa) early on during vase life. Petal abscission is not inhibited by low light intensity nor affected by the Pr/Pfr ratio.

Asparagus plumosus (Baker) is an important cut foliage that does not keep well in vase because of falling cladodes and the change of colour to yellow or brown. Since no information is available on postharvest life of A. plumosus, four experiments were carried out. The best keeping solution is composed of a mixture of 8-HQS 77·10⁻⁵ moles·l⁻¹, AOA 1·10⁻⁵ moles·l⁻¹ and 3, 4, 5 - T 1·10⁻⁵ moles·l⁻¹ and gives a duration to stems of about 30 days in comparison to only 15 days in distilled water. It is also possible to store dry A. plumosus for a maximum of 30 days at 4°C. After storage, vase life in the keeping solution is still about 9-12 days. The weight of fallen cladodes was also evaluated.

Cobalt uptake by cut 'Samantha' roses opened in cobalt solution was investigated. As the cobalt concentration of the holding solution increased (0 to 2 mM), there was a linear increase in cobalt uptake by the cut rose. At lower concentration (0.5 mM) about 95% of the cobalt was equally distributed between the lower and middle stem; as the concentration was raised (1 to 2 mM), these portions became almost saturated and the cobalt apparently accumulated in the lower leaves first, followed by the upper stem and then the upper leaves. After the cut flower sections became progressively saturated, cobalt eventually began to accumulate in the bloom. Some postharvest physiological changes were found to be associated with cobalt concentration in the holding solution as well as the tissue.

Purpose The loss of flower quality after harvesting is a major concern in the floriculture industry. Because cut flower solutions are quickly contaminated with microbes, causing flower damage, they must be modified to enhance and extend the life of the vase. Methods Eco-friendly preservative solutions were examined to investigate the efficiency of natural essential oils of eucalyptus, neem and rosemary at concentrations of 200 and 400 mg L –1 each on the biological, physiological, and anatomical traits and vase life of solidago ( Solidago canadensis ) cut flower. Results Using different essential oils at both concentrations showed significant impact on cut flower longevity. The maximum vase life was obtained by solidago placed in a preservative solution containing 400 mg L –1 of neem essential oil, which enhanced water uptake and relative fresh weight and reduced both water loss and microbial count when compared to other treatments and control treatment. The chlorophyll, total phenol, flavonoid, and carotenoid content of the spikes increased in solidago cut-flower placed in a preservative solution containing neem essential oil 400 mg L −1 . Results also showed decreased malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ) levels and total antioxidant activity (DPPH radical-scavenging activity) with the application of all natural oils supply. Anatomically, cut flowers that treated with essential oils had considerably clearer vessels and significantly fewer bacteria than untreated cut flowers. Conclusion The higher concentration of different essential oils gave better results than the lower concentration. These results suggest that for the floriculture industry, natural phyto-oils provide a clear viable method to extend the vase life of solidago cut flowers. Thus, neem oil at a concentration of 400 mg L –1 added to a preservative solution is considered the most promising practice for prolonging the vase life and maintaining high quality of Solidago.