Abstract
Benzyliso thiocyanate (BITC), an inhibitor of ethylene synthesis and an antimicrobial agent, added to aqueous solutions of a flower preservative, at a concentration of 0.180 mM, decreased ethylene production in apple slices and rose stamens and increased the vase-life of cut flowers of carnation (Dianthus caryophyllus L. cv. White Sim).
Postharvest treatments designed to enhance the vase life of cut Gloriosa rothschildiana flowers were tested. Vase life was significantly extended by the germicides 8-HQC (250 mg·liter-1), DICA (50 mg·liter-1), and Physan-20 (50 mg·liter-1). Germicides acted primarily by improving solution uptake. Sucrose, either as a continuous treatment (of 2% or 5% w/v), or as a 24-hour pulse (20%), significantly enhanced vase life, primarily by enhancing the development of immature buds and delaying senescence in open flowers. Flowers stored at 1C developed signs of chilling injury within 3 days, but chilling symptoms were not displayed in stems stored at 10C for 10 days. Flowers were not affected when exposed to 50 μl ethylene/liter for 24 hours. Transport and short-term storage in sealed, air-filled bags to protect the flowers from physical damage resulted in some atmosphere modification within the bags. Fungal growth occurred when flowers were kept in air-tilled bags for more than 6 days, resulting in a reduction in vase life. Chemical names used: 8-hydroxyquinoline citrate (8-HQC); sodium dichloroisocyanuric acid (DICA); n-alkyl dimethyl ethylbenzyl ammonium chloride (Phyrsan-20).
The postharvest biosynthesis of ethylene and CO2 was measured at 0, 12, 24, and 48 h after harvest and the effects of exogenous applications of 0.0, 0.2, or 1.0 μl·liter–1 ethylene for 20 h was observed on eight speciality cut flower species. Helianthus maximilliani (Maximillian's sunflower), Penstemon digitalis (penstemon), Achillea fillipendulina [`Coronation Gold' (yarrow)], Celosia plumosa [`Forest Fire' (celosia)], Cosmos bipinnatus [`Sensation' (cosmos)], Buddleia davidii (butterfly bush), and Weigela sp. (weigela) exhibited a climacteric-like pattern of ethylene production followed by a steady rise in CO2 production. Echinacea purpurea (coneflower) ethylene biosynthesis was not significant during the 48-h period after harvest. Vase life of coneflower, yarrow, celosia, cosmos, and butterfly bush was not affected by exogenous ethylene. Exogenous ethylene applications to Maximillian's sunflower, penstemon, and weigela resulted in flower abscission and decreased vase life, indicating that they are probably ethylene-sensitive cut flower species.
Abstract
Leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] was grown in controlled environment chambers set for day/night temperatures of 35/24C (high temperature regime, HTR) or 24/13C (low temperature regime, LTR). Fronds were harvested for vase life studies at 1100 and 1800 HR and held in holding rooms in deionized water. Plants were then moved to a greenhouse environment (16–25C) and, after 1 week, an additional set of fronds were harvested. Water uptake of harvested fronds declined exponentially and was generally lower for HTR fronds. HTR fronds had, for the most part, reduced vase life compared to LTR fronds. Most (81%) of the HTR fronds exhibited desiccation symptoms, whereas none of the LTR fronds did. These differences did not appear to be related to preharvest diffusive resistance or water potential differences.
Abstract
Pyrazon [5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone], phenidone (1-phenyl-3-pyrazolidone), BW 755 C(3-amino-l-[m(trifluoromethyl)-phenyl]-2-pyrazoline), and monophenylbutazone (4-butyl-l-phenyl-3, 5-pyrazolidinedione) at 0.1 mM increased the vase life of cut carnations (Dianthus caryophyllus L. ‘White Sim’) by 48% to 85% over that of control flowers. Tiron (l,2-dihydroxybenzene-3,5-disulfonate) also increased vase life about 38% at concentrations of 0.1 and 0.01 μM. These increases were additive to the beneficial effects of the control preservative solution which contained 2% sucrose, 0.02% 8-hydroxyquinoline citrate, and 0.02 m citric acid. A common feature of these compounds is that they are inhibitors of lipoxygenase.
Abstract
Flower longevity (as influenced by stage of maturity at harvest), dry weight, and flower preservative were studied using cut flowers of herbaceous peony (Paeonia spp.) cultivars Felix Crousse, Festiva Maxima, John C. Lee, Mons. Jules Elie, and Richard Carvel. Flowers harvested in the tight calyx stage frequently failed to open or opening was delayed. No substantial difference in longevity between flowers harvested at the loose calyx stage or first loose petal stage was found. Those cut at the loose calyx stage maintained quality well during dry storage at 0°C for up to 4 weeks. Vase-life and days to opening differed significantly with cultivar, length of storage, and their interaction. Fresh weight increased before or during flower opening, and the increase was greater after storage than for unstored flowers. Inclusion of a floral preservative in the vase solution increased gain in fresh weight upon hydration after storage and weight throughout vase-life.
Abstract
Bud-cut carnations kept in opening solutions had about the same diameter, weight, and vase-life as those cut when mature. For opening solutions, sucrose (30g/liter) appeared to be more efficient than glucose. The flower quality at full opening was better with sucrose although the vase-life was slightly longer with glucose. The flower development seemed to depend on the exogenous sugar supply and on the concomitant accumulation of soluble reducing sugars. When cut carnation flowers were supplied with a solution of 14C glucose, only a fraction of the glucose was transformed into sucrose in the stem. The level of 14C hexoses rose in petals, resulting from sucrose hydrolysis in the petals and from glucose directly translocated. A strong isomerase activity occurred in the petals. The leaves had no particular function in the translocation and transformation of sugars. These results are different from those reported earlier for roses.
Abstract
Vase-life of roses (Rosa hybrida L. cv. Forever Yours) placed in the modified Cornell Solution (2% sucrose + 200 mg 8-hydroxyquinoline sulfate/liter) was increased over distilled water by nearly a week. Petal sugars decreased only slightly in roses maintained in distilled water but a rapid decline of respiratory control (RC) of mitochondria occurred after 3 days and was finally lost as vase-life ended. However, petal sugars nearly doubled in flowers in the preservative and the decline in RC of mitochondria occurred at a gradual rate and was never lost. The data indicate that the end of vase-life and the decline in respiration during rose flower senescence is not due to substrate limitations, but to the inability of the mitochondria to utilize the substrate. Exogenous sugars seem to be maintaining mitochondrial structure and function rather than providing substrates.
Abstract
A range of postharvest treatments was applied to cut flowers of the Lily of the Niie, Agapanthus orientalis Hoffmanns cvs, Mooreanus (blue) and Albidus (white), in an effort to improve flower bud opening, vase life, and to reduce floret abscission. Basal treatment of partially opened flowers (2 to 5 florets open) with solutions containing 10–20% sucrose and a bactericide improved bud opening. A 60% to 120% increase in vase life and a substantial reduction in bud abscission (to 20% of the control) was obtained by treating the flowers with the anionic silver-thiosulfate complex (STS) as a basal “pulse” (4 mm Ag+, 3 hr), and spraying the inflorescence with 30 ppm naphthalene acetic acid (NAA) prior to the sucrose pulse. These treatments also were effective in flowers subjected to short-term cold storage (4 days at 1°C).
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.