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1.
The yields of inflorescences, corms and cormlets, and inflorescence quality of winter gladioli were studied under varying illumination levels of 12 hour daylength extension ranging from 0 to 333 lux. The illumination level of the daylength extension for each plot depended on its distance from 2 tungsten halogen light sources mounted at 6 m above ground on poles spaced 8 m apart. The lamps were adjusted for wide beam distribution and aimed at points on the ground 8 m from the base of the poles.Inflorescence yield was increased by increasing the illumination level of daylength extension. The relationship between horizontal illumination level in lux (x) and number of inflorescences (y) was described byy=27.3?10.9 exp(?0.02x)Ninety-seven % of maximum inflorescence yield was obtained at a daylength extension illuminance of 144 lux, while 97% of the maximum number of florets per spike and the other flower quality characteristics were obtained at a daylength extension illumination level of approximately 100 lux. Ninety-seven % of the maximum number of days to flowering was approached at a daylength extension illuminance of 45 lux.There was no clear relationship between the illumination level of daylength extension and number and weight of new corms, or the average weight of each new corm. However, the weights of cormlets per plot and per new corm were higher from plants which received no daylength extension.The commercial application of tungsten halogen lamps to provide daylength extension for winter gladioli production is discussed. 相似文献
2.
A. M. Armitage 《The Journal of Horticultural Science and Biotechnology》2013,88(4):667-674
SummaryExperiments were conducted to determine the appropriate photoperiod, light intensities and sources, and growth regulators, necessary to produce Trachelium caeruleum as a commercially acceptable potted plant. T. caeruleum behaved as an LDP with a critical photoperiod of 14 h necessary for flower initiation but was day neutral for subsequent flower development (from macroscopic bud visibility to anthesis). Providing long days by daylength extension using metal halide (MH) lamps to provide high irradiance resulted in significantly earlier flowering and more flowers than using either MH or incandescent lamps at low irradiance. The use of incandescent lamps to extend the day resulted in slower flowering and fewer flowers than using MH lamps at the same irradiance. Daminozide was effective for controlling plant height but ancymidol and chlormequat were ineffective. Removal of the terminal bud resulted in more compact plants, and more blooms per plant, but delayed flowering by approximately one week. 相似文献
3.
Potted avocado (Persea americana Mill., cv. ‘Fuerte’) plants were maintained in growth cabinets for up to 32 weeks and new growth observed for flower formation. Flowers were formed if temperatures were 20°C or below, but with 25° or 30°, even if only for 1 hour per day, flower formation was inhibited. Time to flowering was accelerated, but number of flowers reduced, if daylength was shortened from 15 h to 9 h. With low temperature and short days, full bloom was about 4 months after starting experiments. Spring flowering of cv. ‘Fuerte’ in the field could follow flower induction about 4 months previously with the onset of winter temperatures and daylengths. 相似文献
4.
The yields of inflorescences, corms and cormlets, and the inflorescence quality of winter-grown gladioli in south-east Queensland, were studied under 2 daylength regimes, 3 plant densities (150 000, 300 000 and 450 000 corms ha?1) and 3 plant arrangements (bed, double row and single row). The daylength treatments were the natural daylength (12.3–14.5 hours) and a 24-hour photoperiod treatment in which natural daylengths were extended using incandescent light of an intensity of 150 lux. Two cultivars were used.Extending the photoperiod to 24 hours delayed flowering by approximately 15 days, and increased the number of inflorescences harvested from low, medium and high density treatments by 20, 91 and 169%, respectively, when compared to the inflorescence yield from these density treatments under natural daylengths. The quality of the inflorescences from the high-density treatment receiving the 24-hour photoperiod was similar or superior in all quality characteristics to that of inflorescences grown under the most favourable density treatment under natural daylengths (150 000 corm ha?1). Plant arrangement had little effect on the number of days to flowering or inflorescence yield but inflorescence quality was improved when plants were grown in a double-row arrangement compared to those from the bed or single-row arrangements. Extension of the photoperiod had no effect on the number of new corms per plot. However, the average weight of new corms and the weight of cormlets per plot and per corm were reduced by approximately 32, 71 and 63%, respectively, when compared to the results obtained from plants grown under natural daylengths. These results suggest that flowers compete for available photosynthates with corms and cormlet development.The economic feasibility of extending photoperiod for the commercial production of winter-grown gladioli in south-east Queensland is discussed. 相似文献
5.
S. BañóN A. González J. A. Fernández J. A. Franco 《The Journal of Horticultural Science and Biotechnology》2013,88(6):851-855
SummaryThe first experiment studied the effect of applying ethylene biosynthesis regulating compounds (ethephon 1000 ppm, silver thiosulphate 0.4 mM and cobalt chloride 5 mM) on the growth and development of Liatris spicata cv. Callilepis. The results pointed to the important growth retardant properties of ethephon and the increased number of flowering stems per corm which could be obtained by pre-planting application. A second experiment aimed to optimize ethephon treatment in Liatris by applying the growth retardant in different concentrations (100, 700, 1300, 1900 and 2500 ppm) at three stages of development: stage I (pre-planting), stage II (immediately after the formation of basal leaf rosette) and stage III (when the main shoot began its rapid longitudinal growth). Besides confirming the effects produced by ethephon in the first experiment, the results suggested that the application of high ethephon concentrations (1900 and 2500 ppm) during stage II of growth produced many miniature flowering stems coming from the principal or secondary shoot. 相似文献
6.
Harald Hildrum 《Scientia Horticulturae》1973,1(1):1-11
The formation of flower buds in Clerodendrum seems not to be affected by day length, but the development of the buds is delayed in long days. When long days were established by means of low-intensity illumination with incandescent lamps, few flowers developed and the stems elongated considerably even at a day length of 16 hours. When fluorescent lamps were used for day-length extension, short shoots with many flowers were obtained even in 24-hour days. Flower development was also delayed by gibberellic acid (GA3), but promoted by chlormequat both in short and long days. Shoot elongation was retarded by chlormequat and promoted by GA3.Plants obtained from commercial greenhouses varied considerably with respect to growth and flowering. By selection a clone was obtained which flowered richly on short shoots. Shoot elongation stopped when flowering began. A ‘negative’ selection gave rise to a clone which flowered sparsely and in which shoot elongation was not influenced by flowering. 相似文献
7.
Gladiolus plants cultivar ‘Spick and Span’ were grown in winter under natural short day (SD) or under long day (LD), with 4 hours low intensity light at midnight. Growth of the various organs was followed by periodic sampling. SD promoted flower development and advanced anthesis but reduced the final size of the flower. LD increased weight and size of leaves and flowers.Initial growth of the corm was similar under both photoperiods, but while corm growth continued throughout the growing-period under SD, it was checked under LD when flowers were developed at an enhanced rate and until anthesis. At this stage, the allocation of assimilates was directed towards the flower sink and away from the corm sink.Final corm weight was also promoted by LD. This is interpreted as an indirect effect due to increased photosynthesis of the larger LD plants. In non-flowering plants raised from cormels, SD specifically promoted corm growth, although no competing flower sink was present.It is concluded that photoperiod affects growth and development of gladiolus in two ways: directly — by affecting the partitioning of assimilates between the flower or the corm; and indirectly — by affecting the total photosynthates available to the plants by influencing foliage size and the total growth period. 相似文献
8.
Optimizing environmental conditions for mass application of mechano-dwarfing stimuli to Arabidopsis.
Jill A Montgomery Ray A Bressan Cary A Mitchell 《Journal of the American Society for Horticultural Science》2004,129(3):339-343
Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs > 60 micromoles m-2 s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs < 60 micromoles m-2 s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 degrees C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 micromoles m-2 s-1, ambient temperatures from 22 to 25 degrees C, and twice-daily brush treatments. 相似文献
9.
Weekly foliar applications of (GA; 25 p.p.m.) during seedling growth promoted reproductive development of both Tagetes patula and Matthiola incana whether grown in short days (8 h), or long days effected by night-breaks (NB). The NB treatment was unfavourable for flowering in Tagetes but promoted leaf growth whereas both GA and NB, favourable for early flowering and associated stem elongation in Matthiola, inhibited leaf growth. The GA applications substituted for the long-day requirement for flowering in Matthiola. These findings are coupled with those reported earlier for the effects of night temperature on vegetative growth and flowering and are discussed in relation to a possible “blue-print” for commercial horticultural practice. 相似文献
10.
试验以4种基因型梨试管苗为试材,在含有MS、ASH、1/2MS、1/4MS及不同IBA和蔗糖浓度的培养基上,采用前期光、暗培养各10d,然后转入有无活性碳(AC)和IBA的处理中在光照下生根。试验用L16(45)正交设计,通过生根率、平均根数、平均根长、平均株根鲜重和平均株根干重5个指标考查了基本培养基、IBA、AC以及光照对梨试管苗生根的影响。结果表明:IBA和蔗糖对于梨根的诱导是十分必要的,而在根的生长阶段IBA不是必需的;1.0～5.0mg/LIBA+5.0～15.0g/L蔗糖+0.5～1.0g/LAC组合下梨的生根率为75%～100%;前期暗培养能有效促进东方梨品种早酥梨和身不知根的发生,而对西洋梨品种巴梨和考密斯根的诱导效果较差。 相似文献