Abstract
Flower bud opening in excised stalks of Limonium sinuatum was promoted by gibberellic acid (GA3) solutions, but bud opening was not stimulated when GA3 was applied to buds only. Feeding detached stalks with sucrose neither increased flower bud opening nor changed the stimulating effect of GA3.
Abstract
Buds of standard chrysanthemums (Chrysanthemum morifolium Ramat cvs. Albatross and Fred Shoesmith) from 5 to 12 cm in diameter were cut with 60 cm stems and stored at low temperatures (−0.5 to 1.5°C) for up to 5 weeks. Flower buds were opened in sucrose solutions containing 25 ppm silver nitrate and 75 ppm citric acid. Small size buds developed flat heads when stored over 2 weeks; the disc florets failed to develop fully. Leaves which are normally free of necrosis when opened in sugar solutions developed desiccation injury after long storage. The flat shape of the inflorescence can be prevented by storing large buds (10-12 cm); however, botrytis becomes a major problem on the exposed ray florets.
Regardless of their maturity at harvest, the vase life of cut inflorescences of the hybrid Limonium `Fantasia' placed in deionized water was 4 to 5 days. A vase solution containing Physan (a quaternary ammonium disinfectant solution) at 200 μl·liter–1 and 20 g sucrose/liter not only prolonged the longevity of individual florets but also promoted bud opening so that the vase life of cut inflorescences extended to 17 days. Pulse treatment with 100 g sucrose/liter in combination with Physan at 200 μl·liter–1 for 12 hours partially substituted for a continuous supply of sucrose. Including 30 mg gibberellic acid/liter in the vase solution was without benefit.
Abstract
Loss of turgor, or moisture depletion, in cut flowers contributes to deterioration. Chemically fortified flower preservatives have been shown to maintain turgor and prolong cut flower life. However, the mechanism by which floral preservatives reduce moisture stress and prevent deterioration is elusive. If physiological responses could be related to preservative components we might be able to explain deterioration and to isolate its causal factors.
Abstract
Flower opening failure was encountered in cut iris flowers (cvs. Wedgwood and Prof. Blaauw) stored at low temperature for 4 days, then held for an additional day at 22°C. The cause was found to be water stress in the flowers as a result of a stem blockage developing during storage and shipment. In flowers harvested with the basalplate of the bulb attached to the stem, the plug apparently develops up into the stem. This failure of flower opening was overcome by pre-shipment cutting of the base of flowers harvested without the basalplate and conditioning in warm water. Conditioning with a preservative solution improved coloration. A new method for water flow resistance measurement in stem sections is described.
Abstract
A 200 ppm solution of Physan-20 [Active ingredients: n-alkyl (60% C14, 30% C16, 5% C12, 5% C18) dimethyl benzyl ammonium chlorides, 10%; n-alkyl (68% C12, 32% C14) dimethyl ethylbenzyl ammonium chlorides, 10%; inert ingredients, 80%.] was as effective in opening buds of ‘Perfecta’ gypsophila as was a 25 ppm silver nitrate solution when combined with sucrose. Sucrose (10%) was more effective in a short time period than 5% in combination with Physan-20. The minimum time in the solution for producing high quality blooms was 4 days. Physan-20, a quaternary ammonium compound, effectively opened gypsophila buds in tap water moderately high in salts, bicarbonates and nitrates. Physan-20 offers an effective alternate to silver nitrate for opening gypsophila without deionized water.
The effect of peracetic acid on the vase life and bud opening of cut flowers of Lisianthus was investigated. Eustoma grandiflorum is an attractive cut flower with a considerable length of vase life (usually weeks for freshly harvested stems). It is well known that the addition of sucrose into the vase solution increases significantly the longevity of cut flowers. Two different experiments of vase life were carried out. The first used cultivars of the Mariachi Series: Blue, Green, Blue Picotee, and Pink, whereas the second used Rosita White and Piccolo White 1. The control plants (T1) were supplied with tap water. Treatment 2 (T2) was similar to T1 with the addition of 3% sucrose. In the third (T3) and fourth (T4) treatments, sodium hypochlorite and a stabilized peracetic mixed system (PAA) were added, respectively. The number of flowers that opened from buds between cultivars was significantly different. With the addition of sucrose into the vase solution, a significant increase in longevity was recorded, which was also observed after the addition of both biocides to the respective treatments. This can be extended up to 15% by the addition of sucrose to the vase solution and up to 30% if PAA is incorporated into the vase solution. The results suggest that PAA can be a useful alternative to sodium hypochlorite for vase solutions because it is without the health drawbacks of trihalomethanes. The degradation of PAA is environmentally friendly, because it decomposes to form biodegradable acetic acid and eventually enters the environment as atomic oxygen.
Abstract
The opening of Freesia hybrida Bailey flowers cut in the tight bud stage was promoted by treatment with sucrose and 200 mg·liter−1 8-hydroxyquinoline citrate. A pulse treatment for 24 to 48 hr with 20% sucrose resulted in complete inflorescence development and prolonged vase life. Reduced sucrose concentrations or increased pulse durations were not as effective. Pulse-treating flowers with 20% sucrose for 24 hr prior to 3 days of simulated shipping improved subsequent flower opening and 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
Promotion of leaf bud break in ‘Golden Delicious’ apple by a mineral oil and dinitro-o-cresol (DNOC) combination spray depended on day-time temperature. Higher temperatures during the first 2 weeks after spraying increased the level of bud break. The highest temperature tested, 30°C, most effectively promoted lateral bud break.