Photoperiodic response and vase life of 28 cultivars of ornamental sunflower (Helianthus annuus) were evaluated. Plants were grown in a glasshouse under 16-hour long-day (LD) or 11.5-hour shortday (SD) conditions. Most cultivars (82%) reached visible flower bud stage earlier under SD than LD. All cultivars flowered under both SD and LD conditions, but in 26 cultivars (92.9%) flowering was significantly delayed under LD, demonstrating them to be quantitative SD plants. The delay was variable among the cultivars. A 14-day or greater hastening of flowering was found under SD in 18 cultivars. Photoperiod had no effect on flowering of `Lemon Eclair' and `Moonshadow'; these cultivars are day-neutral (DN) plants. For some cultivars the LD photoperiod increased plant height and the number of nodes and leaves. Vase life varied from 6.8 to 11.2 days depending on the cultivar, but no photoperiodic effect was found.
The tepals of cut tulips (Tulipa gesneriana L. cv. Ile de France) kept at 20 °C had severely wilted 7 days after flower opening. Suppression of abscission and undesirable growth of tepals is required to extend vase life. Treatment with 50 mm trehalose in combination with 50 μm chloramphenicol (CAP) delayed abscission by 4 days compared with stems placed in distilled water or CAP without trehalose. Only 4% of trehalose+CAP-treated flowers exhibited tepal abscission 7 days after harvest, while 82% and 60% of flowers held in distilled water and CAP, respectively, did so; the tepals of trehalose+CAP-treated flower stems contained 50% more water than did those treated with CAP alone. Further, trehalose did not promote elongation of epidermal parenchyma cells in tepal tissues, but maintained radial enlargement of the cells. Thus, trehalose+CAP treatment is effective in prolonging vase life without abscission, water loss, or elongation of cells in tulip tepals, but slight wilting occurs in leaves.
An experiment was conducted to measure the effects of pulse treatments of BA, sucrose, and BA before, after, or with sucrose, on the vase life of cut Eustoma flowers. A BA pulse at 50 mg·L-1 before 4% sucrose promoted the longevity of cut Eustoma flowers better than other treatments. Simultaneously, sucrose, glucose, and mannose concentrations in flowers during vase periods were maintained at higher levels in double pulse treatments than in the single pulses. Ethylene production in flowers 2 days after vase treatment was highest in the BA-treated flowers; intermediate in flowers pulsed with BA before, after, or with sucrose; and lowest in sucrose-treated flowers. Although a BA pulse increased ethylene production over that of controls, it inhibited senescence in cut Eustoma flowers. Respiration in flowers pulse-treated with sucrose or with BA before, after, or with sucrose, was significantly higher than that in controls. Results suggest that the vase life of cut Eustoma flowers is improved by either BA or sucrose in vase solution and especially when BA was pulsed before the sucrose pulse. Chemical name used: N6-benzyladenine (BA).
Continuous postharvest treatment of carnation flowers (Dianthus caryophyllus L. cv. Elliot's White) with 50 or 100 mM aminotriazole significantly extended useful vase life relative to flowers held in distilled H2O. No morphological changes symptomatic of floral senescence appeared in treated flowers until 12 to 15 days after harvest. The longevity of aminotriazole-treated flowers was extended to ≈18 days. The respiratory rate of aminotriazole-treated carnations was suppressed, and they exhibited no respiratory climacteric throughout the period of observation. The responsiveness of aminotriazole-treated flowers to exogenous ethylene appeared temporally regulated. Flowers treated with 50 mM aminotriazole for 2 days senesced in response to application of 10 μl exogenous ethylene/liter, whereas flowers treated for 24 days exhibited no morphological response to ethylene treatment. Chemical name used: 3-1H-amino-1,2,4-triazole-1-yl (aminotriazole).
A broad source of Gerbera × hybrida Hort. germplasm was evaluated for vase life. Senescence mode, i.e., bending or folding of stems or wilting of ligulae was also recorded for flowers evaluated. Intensive selection was practiced to improve vase life. About 10% of the plants from a sample population were selected for having flowers with high vase life. Progeny means for vase life resulting from a topcross between these plants and `Appleblossom' were used to select five plants (about 1.5% of the sample population) whose flowers had high vase life. A diallel cross using these five plants as parents resulted in a progeny population with an increase in mean vase life of 3.4 days compared to mean vase life for the initial sample population. Increases in vase life means for days to bending, folding, and wilting were 0.3, 3.5, and 1.2 days, respectively. Plants with flowers which senesced due to wilting had the longest mean vase life before and after breeding. Changes in proportion of senescence modes were observed; bending decreased, folding and wilting increased. Frequencies of bending, folding, and wilting were compared to vase life means for 10 progenies. Proportion of bending generally decreased as vase life increased.
Storage at 4.5°C prevented decay of cut fronds of leatherleaf fern [Rumohra adiantiformis (G. Forst) Ching] artificially inoculated with Cylindrocladium heptaseptatum Sobers, Alfieri, & Knauss and/or naturally infected with C. pteridis Wolf and increased frond vase-life compared to 24° storage. Storage at 4.5° for 10, 21, and 31 days did not affect subsequent frond vase-life. Inoculation of fronds decreased vase life by 11% in one experiment and had no effect in a second. Prestorage dips in benomyl suspensions at concentrations as low as 38 ppm reduced frond decay by 82% when stored at 24° and increased vase-life of fern stored at both 4.5° and 24°. Benomyl [methyl l-(butylcarbamoyl)-2-benzimidazole-carbamate] dips at concentrations as high as 300 ppm had no detrimental effect on vase-life. Iprodione [3-(3,5-dichlorophenyl)-N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecarboxamide] had no effect on vase-life.
Short-term or over-night pretreatment with solutions of a silver thiosulfate complex extended the vase life of fresh or stored miniature carnations (Dianthus caryophyllus L.) as much as the continuous use of commercial vase preservatives. Combining the 2 treatments further extended the vase life to 4 times that of control flowers. The time to wilting of the first flower was closely correlated with the mean vase life of all the flowers in a spray.
Addition of rhizbitoxin analogs to holding solutions extended vase life of bulbous iris flowers (Iris xiphium L), daffodils (Narcissus pseudo-narcissus L.) and chrysanthemums (Chrysanthemum morifolium Ramat). Sodium benzoate also increased vase life of daffodils butnot of irises and chrysanthemums. Isopentenyl adenosine delayed senesence of irises but not of chrysanthemums. None of the chemicals tested extended the vase life of roses (Rosa hybrida L). Ethylene production in rose petal tissue was reduced by rhizobitoxine analogs indicating that roses do not have a rhizobitoxine-resistant ethylene producing system. Results suggested that either roses are sensitive to low levels of ethylene or their senescence is triggered by factors other than ethylene.
The beneficial effects of de-ionized (DI) or distilled (Dist) water and/or preservative on extending the vase-life of Chrysanthemum morifolium, Ramat. ‘May Shoesmith’ flowers varied depending upon their combinations and on flower source. Generally, the addition of preservative, regardless of water quality, was beneficial as was the use of DI or Dist water alone compared to tap water alone or tap water plus preservative. Maximum vase-life was generaUy achieved using DI or Dist water plus preservative but preharvest factors also greatly influenced vase-life.
Aminooxyacetic acid (AOAA) at a concentration of 0.5 mM extended the vase life of carnations (Dianthus caryophyllus L. cv. White Sim) to a degree comparable to that shown by 0.1 mM aminoethoxyvinylglycine (AVG) (71 to 94%). Increases in vase life ranging from 22 to 53% were also obtained with N-[2-(2-oxo-l-imidazolidinyl) ethyl]-N’-phenylurea (EDU), carbonylcyanide m-chlorophenyl-hydrazone (CCCP), spermidine, putrescine, or spermine. Combinations of AVG and EDU or AOAA and EDU further extended the vase life 134 to 140% over that of the control flowers. These increases were additive to the beneficial effects obtained from the control preservative solution, which contained 2% sucrose and 200 ppm 8-hydroxyquinoline citrate.