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Abstract

Short pretreatments of stems of anthurium flowers (Anthurium andraeanum André) with silver nitrate solutions increased vase life by 40 to 60% after a simulated shipping. Significant improvement was obtained with a single 10-minute treatment with 1 mm silver nitrate. Maximum postharvest life was obtained with flowers treated with silver nitrate within 12 hours of harvest. Silver nitrate treatment was effective on flowers ranging from half to full maturity. No measurable silver was translocated to the spathe or spadix. Silver thiosulfate complex was not as effective as silver nitrate. For response to silver treatment following simulated shipping of 3 days, 2 cm of stem had to be removed before placing in a vase solution. Continuous maintenance of the flower before and after simulated shipping in a commercial preservative was not significantly better than a single pulse with silver nitrate or a combination of silver nitrate pulse and commercial preservative.

Lupinus havardii has gained popularity as a potentially new and unique cut flower species, but its compound, ethylene-sensitive inflorescences (racemes) undergo rapid senescence and deterioration on cutting. The purpose of this study was to evaluate the influence of Ca culture solution applications on L. havardii cut-flower longevity. Four supplemental Ca treatments were incorporated into the nutrient solution (0, 2.5, 5.0, and 10.0 mM Ca using CaCl₂), with four replications in a randomized complete-block design. Raceme Ca concentration increased with increasing Ca application, ranging from a low 5300 mg·kg^-1 dry weight (0 mM supplemental Ca) to a high of 7500 mg·kg^-1 (10.0 mM supplemental Ca). Calcium application deferred the daily loss in raceme fresh weight (FW) for up to 10 days of vase life in a concentration-dependent manner (P < 0.01), with the effect most pronounced between 5 and 9 days following cutting (average FW of 72% and 83% of day zero values for the control and 10.0 mM Ca, respectively, with 2.5 and 5.0 mM treatments intermediate). The cut racemes of L. havardii are model organs for spatially and sequentially organized postharvest development, with continued, 6-day postcutting life including 4-fold increases in cell permeability of basal, most mature flowers, marginal but significant increases in cell permeability of the most recently expanded flowers, and a 50% increase in total flowers number resulting from inflorescence expansion. Preliminary data indicate that manipulation of Ca nutrition may be a viable, inexpensive, and environmentally safe alternative to silver-based compounds currently in use for the vase life extension of L. havardii inflorescences.

The vase life of roses grown in coal bottom ash (CBA)-amended media was evaluated. CBA is enriched in calcium, a nutrient implicated in delaying senescence. Two rose cultivars, Cara Mia and Dakota, were grown (from started eye plants) in four media: a 50% CBA medium and a peat:vermiculite medium amended with calcitic and dolomitic lime (1:1) were used as “high calcium” media, whereas a 25% CBA medium and a peat:vermiculite medium amended with dolomitic lime only were used as “low calcium” media. Vase life of the freshly harvested roses was evaluated. Elemental analysis of the leaves showed that roses grown in the “high calcium” media had greater calcium in the leaf tissue as well as longer vase lives (12.6 and 13.5 days) when compared to those grown in the “low calcium” media (12.1 and 10.9 days). However, petal tissue Ca was not affected by media and was not correlated with vase life. Petal tissue calcium was ≈15 times lower than leaf tissue calcium. Calcium and magnesium increased in the petal tissue over the vase life of the senescing petals. A comparison of `Cara Mia' roses (vase life of 14 days) and `Dakota' roses (vase life of 8.5 days) showed that the longer-lived `Cara Mia' had lower leaf and petal calcium levels. Both varieties followed a similar kinetics of electrolyte leakage (total E.C. and K) during their respective vase lives.

Six preemergence herbicides were applied twice a year at 1x and 2x rates for 2 years to leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] starting from the time of rhizome planting. Predominant weeds present were Cardimine hirsuta, Erechrites hieracifolia, Oxalis stricta, and Phyllanthus tenellus. All herbicides, except pendimethalin and oxadiazon at the 1x rates, reduced weed biomass by 60% to 99% compared to the unweeded control during the fern bed establishment phase (year 1). During that period, hand-weeding times were reduced (51% to 95%) by prodiamine and dithiopyr at both rates, and oxadiazon and pendimethalin at 2x rates. During year 2, herbicides were of greatly reduced benefit due to reduced weed growth caused by the increasingly competitive fern. After 2 years, only 2x dithiopyr-treated plots had reduced yields compared to the hand-weeded controls. Herbicide treatments had no detrimental effects on frond postharvest longevity. In fact, fronds harvested from the 1x isoxaben-treated plots exhibited increased vase life compared to the controls.

Effects of postimportation treatment of benzyladenine (BA) on vase life of imported anthurium flowers was examined after receiving the flowers in Japan and placing them either individually or together in vase solution. Cut anthuriums of two cultivars imported from Hawaii via air-freight were sprayed with 200 μg·m L^–1 of BA upon arrival, and vase life of the flowers were evaluated by numerating days before observing apparent discoloration at the distal end of spadix. BA treatment significantly extended the vase life (by up to 22 d) in two cultivars in most cases during summer, but the effect was inconsistent in each cultivar when the test was done in winter. The effect of BA verified in summer was either nullified or significantly diminished by placing 10 flowers together in vase solution. In these tests, bacteria were isolated more frequently from the scape segments of bunched flowers than those of individual flowers. However, vase life was not affected when the vase solutions were inoculated with Xanthomonas axonopodis pv. dieffenbachiae. These results indicate that the postimportation BA treatment is mostly effective in extending the vase life of cut anthuriums during summer, but may not be reliable during winter in temperate regions. The preliminary evidence suggests that bacterial growth in vase solution be related to the loss of the effect of BA, but the pathogen of bacterial blight growing in the vase solution or invading the xylem of the scape is not responsible for the reduced longevity of imported anthuriums.

`Testarossa' gerbera (Gerbera jamesonii Bolus) scapes were injected with distilled water (control), or 0.3, 0.6, and 0.9 mm ACC at harvest, then held at 20 °C for 15 days in a preservative solution. PAL activity and ethylene production increased within 1 day proportionally to injected ACC. ACC injection reduced bending incidence, inhibited flower scape elongation, enhanced firmness of the flower scapes and increased vase life. Flower scapes treated with ACC reached full maturity 3 days before the end of vase life of the control, which bent before reaching full maturity.

Abstract

Effects of a mixed bed ion exchange resin column on vascular blockage and vase life were studied in cut roses (Rosa hybrida L. cv. Red American beauty) by measuring blockage rates in excised stem sections and by determining water uptake, fresh weight retention, and longevity of cut roses held in distilled water. The ion exchange column inhibited vascular blockage in excised stem segments. Water uptake and retention of fresh weight of cut roses were enhanced significantly by the ion exchange column treatment, and early wilting, known as “bent neck” was inhibited.

Abstract

Six carnation cultivars from Colorado and from California were cut as ¾- to 1-inch buds and shipped during each of the spring, summer, fall, and winter seasons. After arrival, usually 2 days after cutting, loose buds opened in 1–2 days at 75° F in a preservative; tighter buds sometimes required 3–4 days. A low relative humidity of 42–45% was as satisfactory as 80–85% during the few days required for opening buds. Vase life at 70° was 13–15 days when buds were opened on arrival and held continuously in a preservative, 12–14 days when stored 1 week at 40° before opening, and 7–14 days when stored 3 weeks at 32°–33°. Bud-cut carnations held in water after shipment had a vase life of 4–5 days. Some lots and cultivars were injured after 3 weeks at 32°–33° and never opened well.

Three preservatives were tested and found satisfactory for opening buds after shipment or after shipment plus storage. Use of Cornell solution (5% sucrose, 200 ppm 8-hydroxyquinoline sulfate and 50 ppm silver acetate) for opening and display usually produced the largest blooms with the longest life. Two percent “Ever-bloom” and a solution containing 3% sucrose, 400 ppm 8-hydroxyquinoline citrate and 300 ppm “Alar” were other satisfactory preservatives for use with bud-cut carnations after shipment.

Refrigerated (2 °C) controlled atmospheres significantly increased the mortality of green peach aphids [Myzus persicae (Sulzer)] and western flower thrips [Frankliniella occidentalis (Pergande)] in laboratory experiments. However, insect mortality during marine shipment in mixedload containers at 0.5 °C did not significantly increase in a controlled atmosphere. In laboratory experiments, mortality of green peach aphids ranged from 32.8% in the refrigerated control to 96.8% after storage in 0.10% O₂ for 4 d followed by 7 d in 3% O₂ with 5% CO₂. When stored under these same conditions, western flower thrips mortality was 71% compared to 16% mortality in the refrigerated control. Following an 11-day marine shipment from California to Guam in a controlled atmosphere, vase life was extended for most of the 20 California cut-flower and foliage products compared to those shipped in the refrigerated air control.

Abstract

Treatment of ‘Scania’ standard carnations and ‘Elegance’ spray carnations (Dianthus caryophyllus L.) with silver thiosulate and the biocide Physan before shipment markedly extended shelf life in deionized water after arrival. The treatment extended vase life of ‘Scania’ and ‘Elegance’ 11.5 and 5.2 days, respectively, over controls. Pretreatment of ‘Captain Busch’ gladiolus Gladiolus × hortulanus L. H. Bailey with silver thiosulfate alone or with a 10% sucrose pulse improved the quality of the spikes but did not extend vase life after shipment.