cooled in complete darkness to induce flower initiation. Additional research is needed to obtain more data to study if induction in darkness or under low PPF would negatively impact flower quality of the nobile dendrobium. The objective of this study
Min Lin, Terri W. Starman, Yin-Tung Wang and Genhua Niu
Hazel Y. Wetzstein, Weiguang Yi, Justin A. Porter and Nadav Ravid
with vestigial development ( Holland et al., 2009 ; Wetzstein et al., 2011a ). This indicates that flower quality is inconsistent, and that even within bisexual flower types, the strength and vigor of individual flowers are variable. This leads to the
Muhammad Maqbool and Steven E. Newman
Twelve snapdragon cultivars of different response groups were grown in a double polyethylene greenhouse to determine the impact of no root-zone heat (RZH) and 22C RZH at 15 or 20C night air temperature (NT) on flower quality. Data were recorded when the first floret of each stem showed color and harvested when the lower third of the florets were open, Flower quality was evaluated at harvest based upon stem length and fresh weight using Society of American Florists standards. Cultivars `Butterfly White II', `Hercules', `Navajo', and West Virginia' (Group II) were the first to bloom under 20C NT regardless of RZH; whereas cultivars `Oklahoma', Houston', and `Potomac Pink' (Group IV) were delayed. Similar trends were observed under 15C NT, but the crop was harvested a few days earlier with RZH as compared to no heat. Flower quality was better under 15C NT.
Yan Chen, Donald Merhaut and J. Ole Becker
Nitrogen (N) fertilization is critical for successful production of cut flowers in a hydroponic system. In this study, two sunflower cultivars: single-stand `Mezzulah' and multi-stand `Golden Cheer' were grown under two N fertilization rates: 50 mg·L-1 and 100 mg·L-1 in a recirculating hydroponic system. At the same time, `Mezzulah' sunflowers were biologically stressed by exposing each plant to 2000 second-stage juveniles of the plant parasitic nematode Meloidogyne incognita, race 1. The experiment was conducted in May and repeated in Sept. 2004, and plant growth and flower quality between control and nematode-infested plants were compared at the two N rates. The two cultivars responded differently to fertilization treatments. With increasing N rate, the dry weight of `Mezzulah' increased, while that of `Golden Cheer' decreased. Flower size and harvest time were significantly different between the two cultivars. However, N had no effect on flower quality and harvest time. Flower quality rating suggests that quality cut stems can be obtained with 50 mg·L-1 N nutrient solution. Nematode egg count suggests that plants in the nematode treatment were successfully infested with Meloidogyne incognita, however, no significant root galling was observed, and plant growth and flower quality were not affected by nematode infestation.
Robert G. Anderson
Greenhouse grown cut stems of satin flower were used in a series of postharvest experiments to determine the effect of sucrose on flower life, flower quality and the overall vaselife. Experiments in 1993 compared 0, 0.5, 1.0 and 2.0% sucrose in tap water with and without a biocide (4 ppm sodium hypochlorite). Cut stems of `Grace Rose Pink,' `Grace Salmon and `Grace Red' were harvested, stored in a refrigerator overnight at l-2” C.; all cut stems were maintained in randomized individual vases in a room kept at 22-23 C with fluorescent lighting (50 ft.c.) from 0800-2000 HR. Postharvest performance was best in tap water, tap water + biocide, and 0.5% sucrose + biocide with excellent flower opening and flower quality for 10-14 days. Leaf yellowing and leaf necrosis increased greatly with the increasing concentrations of sucrose. Flowers of `Grace Salmon' showed significant petal necrosis in the treatments with higher concentrations of sucrose.
Susan S. Han, Abraham H. Halevy, Roy M. Sachs and Michael S. Reid
Flowering of brodiaea (Triteleia laxa syn. Brodiaea laxa `Queen Fabiola') did not have an obligate requirement for manipulation of temperature or photoperiod. Vernalization of corms reduced the greenhouse forcing phase but did not alter the number of flowers per inflorescence or scape length. Long photoperiods hastened flowering but decreased flower quality and flowering percentage. Scape length, which was not affected by photoperiod or mother corm size, was increased when plants were grown at night temperatures < 10C. Diameter of the apical meristem in the dormant corm, flowering percentage, and flower quality were not affected by a 10-fold increase in corm size above a critical weight (0.6 g). In contrast, the weight and number of daughter corms were closely correlated with mother corm size. The optimum planting depth for brodiaea corms was 10 cm below the soil surface.
Wayne A. Mackay and Narendra Sankhla
Phlox paniculata `John Fanick' produces long lasting, dense terminal flower heads and has potential as a specialty cut flower. Quality and postharvest display life of cut flower heads depends primarily on ethylene-induced flower abscission, flower bud opening, and maintenance and development of flower color during vase life. Late events, such as flower and leaf senescence may also be detrimental to flower quality. In the control treatment, the initial red-pink and purple flower color changes to violet blue in 3 to 4 days, and may lose >50% of initial anthocyanins. Incorporating sucrose (SUC) in the vase solution not only maintained >75% of the initial floral pigments, but also promoted opening of additional flowers and anthocyanin development. Although both ethylene biosynthesis (AOA, ReTain, a.i. AVG) and action inhibitors (STS, 1-MCP) delayed flower abscission, STS and 1-MCP were relatively more effective than AOA and AVG. As in the control, newly opened flowers remained very small when treated with ethylene inhibitors, did not develop red-pink color, and exhibited only shades of violet blue color. Sucrose antagonized the effect of ethylene inhibitors. As such, the flowers in SUC+ethylene inhibitors treatments enlarged in size and developed a reddish-pink blue color. However, the flower quality in SUC alone was much superior than those in SUC+ethylene inhibitors. These results indicate that ethylene inhibitors, alone and in combination with SUC, were not of any additional value in improving postharvest performance and display life of cut phlox flower heads.
R.J. Henny, T.A. Mellich and D.J. Norman
Thirty-one spathiphyllum (Spathiphyllum Schott.) cultivars were evaluated for flowering response following treatment with gibberellic acid (GA3). Greenhouse-grown plants were treated once with 250 mg·L-1 (ppm) GA3 applied as a foliar spray. Within 16 weeks after treatment all GA3-treated plants had flowered but none of the untreated controls produced flowers. `Vickilynn' (14.1 flowers/plant after 16 weeks), `Piccolino' (12.8), `Mascha' (12.6), `Chris' (11.7), `Alpha' (11.7), and `Daniel' (11.0) produced significantly more flowers than other cultivars. The cultivars producing the fewest flowers per plant after 16 weeks were `Sierra' (2.5), `S1008' (3.2), `Rica' (3.4), `Sonya' (4.3), `Vanessa' (5.1), `S18' (5.5) and `S4002' (5.6). `Alpha,' `Textura,' `Daniel,' `Mascha,' `S1007', and `Showpiece' had significantly better flower quality. `S1008,' `Codys Color', and `Petite' had poor flower quality. `Mascha' was the earliest cultivar to bloom producing maximum flower counts during weeks 9 to 10 after treatment while `Vanessa' was the latest to flower with peak bloom occurring 15 to 16 weeks after treatment. Most cultivars reached peak bloom at 11 to 13 weeks after treatment. Results indicate sufficient genetic variability in spathiphyllum flowering response to GA3 treatment exists to permit cultivar selections based on differences in flowering time, number of flowers and flower quality.
Nirit Bernstein, Marina Ioffe, Moshe Bruner, Yair Nishri, Gideon Luria, Irit Dori, Eli Matan, Sonia Philosoph-Hadas, Nakdimon Umiel and Amir Hagiladi
The form of N supplied to the plant (NH4 + or NO3 –) affects growth, morphology and a range of physiological processes in the plant. Little information is available concerning the effects of N form on development, production or quality of cut-flowers. The present study investigated for the first time the effects of N form and quantity on growth, flower production and flower quality of Ranunculus asiaticus L. The plants were cultivated in an inert mineral soilless medium (perlite) and were exposed to two levels of nitrogen fertilization (50 or 100 ppm) and three levels of NH + 4 (10%, 20%, or 30%, under 100 ppm nitrogen fertilization). Larger shoots and increased shoot/root ratios were obtained in the lowest (50 ppm) N treatment. This treatment also excelled in flower yield production, resulting in higher numbers of total flower produced as well as higher numbers of long flowers. The results demonstrate an effect of N ferlilization treatments on cut-flower quality. Flowers grown under 50 ppm N application characterized by almost double vase life duration compared to flowers grown under the various 100 ppm N treatments. However, flower quantity and quality were not affected by the level of NH4 applied. The R. asiaticus L. root was less sensitive to the N fertilization treatments than its shoot. Contents of organic N, NO – 3, P, K, Ca, Mg, Na, Cl, Fe, Cu, Zn, B, and Mo in the leaves were not affected by the fertilization treatments. Taken together, our results suggest a low requirement of R. asiaticus L. for N fertilization, and insensitivity to ammonium concentrations in the range of 10 to 30 ppm, 10% to 30% of the total N supplied. Detrimental effects in terms of growth, production and cut flower quality were apparent already under 100 ppm N supply.
Group-author : R. Socias i Company
Bloom evolution and flower quality were studied in 10 almond [Prunus amygdalus Batsch syn. P. dulcis (Mill.) D.A. Webb] selections of the Zaragoza breeding program. The opening of individual flowers followed a normal distribution, with deviations reflecting temperature differences during the bloom period. The first open flowers are of better quality than later ones and may contribute more to fruit set. The relative stigma–anther position reflected the possibility of natural autogamy in three of the 10 selections. Natural autogamy might allow single-cultivar orchards without the need for pollinating insects.