Effects of growth regulators on growth and flowering in Hippeastrum hybridum hort

Soaking of bulbs in 3 concentrations of indoleacetic acid (IAA), gibberellic acid (GA₃), 2-chloroethyltrimethyl ammonium chloride (cycocel) or 2-chloroethylphosphonic acid (ethrel) showed various responses on growth and flowering. IAA increased the weight and number of bulblets, GA₃ increased bulb weight. Cycocel (1000 mg l^?1) increased the number of flowers, while GA₃ increased the diameter of the flowers.Application of IAA at 100 mg l^?1 and GA₃ at 10, 100 or 1000 mg l^?1 twice as foliar spray at an interval of 30 days promoted the number of bulblets on the treated plants, while high concentrations of cycocel and ethrel (1000 mg l^?1) increased the weight of bulblets. All concentrations of IAA, GA₃ and 1000 mg l^?1 cycocel increased the number and size of the flowers.     

Effects of photoperiod,light source and growth regulators on the growth and flowering of Trachelium caeruleum

Summary

Experiments 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.     

Plant growth regulators and flowering of Brunonia and Calandrinia sp.

Brunonia australis R. Br (Goodeniaceae) and Calandrinia (Portulacaceae), native to Australia, are potential new flowering potted plants. This research investigated the role of daylength and growth regulators, Gibberellic acid (GA₃) and paclobutrazol (Pac), to control vegetative growth, peduncle elongation and flowering of Brunonia and Calandrinia. Plants were grown under long days (16 h), short days (11 h) and 8 weeks under short day then transferred to long day (SDLDs). Plants in each daylength were treated with GA₃, Pac, and GA₃+ Pac. GA₃ was applied as 10 μL drop of 500 mg L⁻¹ concentration to the newest mature leaf. A single application of Pac was applied as a soil drench at 0.25 mg a.i. dose per plant. Both Brunonia and Calandrinia flowered earlier in long days but still flowered in short days, so both can be classified as facultative LD plants. Brunonia under SDLDs were more vigorous and attractive than plants under LDs while still being more compact than plants under SDs. In Brunonia, GA₃ promoted earlier flowering and increased the number of inflorescences under SDs. Pac at 0.25 mg a.i. per plant applied alone or in combination with GA₃ had extended flower development in Brunonia, and resulted in a reduced number of inflorescences per plant compared to the control plants. Vegetative growth of Calandrinia was similar under LDs, SDs and SDLDs, whereas GA₃ application increased plant size. Pac-treated Calandrinia looked compact and attractive, and Pac application did not affect time to flower and flower number.     

Effect of temperatures and growth regulators on fruit malformation in tomato

The effects of temperatures and growth regulators on deformations in tomato fruits, a common occurrence in winter, were examined in greenhouses and in controlled-climate conditions with cultivars ‘Arava’ and ‘Orith’. The malformations could be attributed both to low-temperature conditions during flower development and to the use of growth regulators. Deformations caused by low temperatures differed from those caused by growth regulators. As a result of flower development under low-temperature conditions, fasciated fruits, fruits with a navel-like scar at the blossom end, puffy (hollow) fruits, and seedless fruits were obtained, where as with growth regulators there were more seedless fruits, sharply elongated blossom ends and green jelly. The 2 cultivars tested differed in their susceptibility to low-temperature conditions and growth regulators.     

The effect of day length,source of light and growth regulators on growth and flowering of Clerodendrum thomsonae Balf

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.     

Effect of relative humidity on growth and flowering of some greenhouse plants

Young plants of 10 different greenhouse species were grown from 24 to 100 days at 55–60, 70–75 or 90–95% relative humidity (RH) in growth rooms. The dry weight increased significantly by increasing RH from the lowest to the highest level in Begonia × hiemalis (47%), Saintpaulia ionantha (17–36%), Euphorbia pulcherrima (31%), Chrysanthemum × morifolium (31%), Nephrolepis exaltata (68%) and Lycopersicon esculentum (20%). The dry weight of Campanula isophylla, Rosa, Cucumis sativa and Lactuca sativa was not affected by RH, while Soleirolia soleirolii was negatively affected. The fresh weights of Cucumis and Lactuca, however, increased with RH in spite of there being no effects on the dry weights. Shoot length increased very considerably by raising the RH in most of the species. The number of leaves was increased by RH in some of the species while not in others. Number of flowers and flower buds significantly increased with RH in Saintpaulia, and time to flowering was reduced with RH in Saintpaulia, Begonia and Campanula.     

喷施蔗糖对菜薹营养品质及产量的影响

为提高菜薹的营养价值、改善其综合品质,以菜薹‘油绿501’为试材,采用叶面喷施的方式,探究不同浓度的外源蔗糖溶液处理对菜薹营养品质及产量的影响。结果表明,质量浓度为0.1 g·L~(-1)和0.2 g·L~(-1)的蔗糖处理均能显著提高菜薹中可溶性糖含量,0.2 g·L~(-1)和0.4 g·L~(-1)的蔗糖处理均能显著提高其总酚、芥子油苷、花青素含量,且二者间促进效果差异不显著;不同浓度的蔗糖处理对菜薹单株产量的影响不显著。因此,在生产中可采用质量浓度为0.2 g·L~(-1)的蔗糖溶液喷施菜薹幼苗,提高其营养价值。     

Effect of maleic hydrazide on vegetative growth,flowering and fruiting of bottle gourd

A study on the effect of maleic hydrazide (MH) on vegetative growth, flowering and yield of bottle gourd (Lagenaria siceraria (Mol) Standl.) was conducted during the rainy and summer seasons of 1979 and 1980, respectively. MH at 150 mg l^?1 stimulated the elongation of the main shoot, while MH at 50 mg l^?1 induced more branches per plant. Staminate flowers appeared late and at the lowest node number in control plants, whereas MH at 150 mg l^?1 had a profound effect on the earliest appearance of pistillate flowers at the lowest node number. Male: female ratio was lowered with MH at 50 mg l^?1 and was most effective in producing the maximum number of fruits and fruit weight per plant and ultimately the yield. GA₃, NAA and ethrel did not influence yield, while MH did.     

Growth and flowering of black iris (Iris nigricans Dinsm.) following treatment with plant growth regulators

The effects of application method and concentration of gibberellic acid (GA₃), paclobutrazol and chlormequat on black iris performance were assessed. Plants (10 cm high, 4 ± 1 leaves) were sprayed with 125, 250, 375 or 500 mg L⁻¹ or drenched with 0.25, 0.5, 1 or 2 mg L⁻¹ GA₃. In a second experiment, the plants were sprayed with 100, 250, 500 or 1000 mg L⁻¹ or drenched with 0.25, 0.5, 1 or 2 mg L⁻¹ paclobutrazol. Other plants were sprayed with 250, 500, 1000 or 1500 mg L⁻¹ or drenched with 100, 250, 375 or 550 mg L⁻¹ chlormequat. In each experiment, the control treatment consisted of untreated plants. Results indicated that the tallest plants (37.3 cm) in the GA₃ experiment were those sprayed with 250 mg L⁻¹. The most rapid flowering (160 days after planting) occurred when a 375 mg L⁻¹ GA₃ spray was used, whereas flowering was delayed to 200 days using 1 mg L⁻¹ GA₃ drench. Drenching with 1 mg L⁻¹ GA₃ increased height of the flower stalk by 7 cm compared to the control. Though relatively slow to flower, plants drenched with 1 mg L⁻¹ GA₃ had long and rigid stalks, which were suitable as cut flowers. Number and characteristics of the sprouts were not affected by GA₃. All paclobutrazol sprays resulted in leaf falcation. A 500 or 1000 mg L⁻¹ paclobutrazol spray resulted in severe and undesirable control of plant height, drastic reduction in stalk height and weight, and delayed flowering. Plants drenched with 0.25 or 1 mg L⁻¹ paclobutrazol were suitable as pot plants. Chlormequat reduced plant height only at the highest drench concentration, which also reduced flowering to 70%. No leaf falcation was observed with GA₃ or chlormequat. Chemical names: ( ± )-(R*,R*)-beta-((4-chlorophenyl)methyl)-alpha-(1,1,-dimethylethyl)-1H-1,2,4,-triazol-1-ethanol (paclobutrazol); (2-chloroethyl) trimethylammonium chloride (chlormequat).     

Water relations in passionfruit: Effect of moisture stress on growth,flowering and nutrient uptake

The response of passionfruit hybrids (Passiflora edulis f. edulis × P. edulis f. flavicarpa cultivar E-23 on P. edulis f. flavicarpa seedling rootstocks) to soil moisture was evaluated in a heated glasshouse by irrigating when soil water pressure potential fell to −0.0025, −0.01, −0.14 and −1.5 MPa. Leaf, stem and root dry weight, leaf area, vine extension and node, flower bud and open flower number were reduced by soil moisture stress. Changes were also noted in a range of morphological characteristics. Reductions in growth and flowering were associated with reduced nutrient uptake and leaf water potential, but not leaf conductance. It was concluded that moisture stress may be one of the major environmental factors responsible for seasonal fluctuations in passionfruit yields.     

Effect of temperature on growth and flowering of litchi (Litchi chinensis Sonn.) cultivars

Summary

Moderate day/night temperatures (20/15° v. 15/10°C) increased vegetative growth and reduced flowering in the seven litchi cvs Tai So, Bengal, Souey Tung, Kwai May Pink, Kwai May Red, Salathiel and Wai Chee. At higher temperatures (25/20° and 30/25°C), vegetative growth was promoted further and flowering eliminated. Temperature also influenced the type of inflorescence formed. More leaves were formed on the panicles of trees growing at 20/15° than at 15/10°C. All terminal shoots on all cultivars produced panicles at 15/10°C. The relative order for the amount of flowering at 20/15°C was: ‘Wai Chee’>‘Salathiel’>‘Kwai May Pink’>‘Tai So’>‘Bengal’>‘Souey Tung’>‘Kwai May Red’. Cultivars which were vigorous at high temperatures produced fewer panicles at 20/15°C and fewer leafless panicles at 15/10°C. Only small differences were observed in the leaf water potential and the nutrient status of the shoots at different temperatures. Vigour and flowering of the cultivars in the glasshouse generally reflected field performance in subtropical Australia (Lat. 27°S). Low vigour could be useful for selecting litchi cultivars for good fruiting in environments with warm autumns and winters.     

Effect of low temperatures during flowering on floral cycle and pollen tube growth in nine avocado cultivars

The floral response of the type A avocado cultivars ‘Reed’, ‘Wurtz’, ‘Rincon’ and ‘Jalna’, and the type B cultivars ‘Bacon’, ‘Ryan’, ‘Edranol’, ‘Sharwil’ and ‘Hazzard’ was tested under growth-cabinet conditions of 17° C day, 12° C night, with a 12-h photoperiod and photon flux density of 400 μE m^?2 s^?1 (400–700 nm). Most of the flowers of all type A cultivars and the type B cultivar ‘Bacon’ had both a female and a male stage. None of the flowers of the other type B cultivars had a female stage but opened in the male stage only. Hand pollination resulted in some ovule penetration in the cultivars with female stage flowers. In those with only male-stage flowers, the pollen tubes grew no further than the style. Maintenance of fertility under low-temperature conditions during flowering appeared to be partly, but not entirely, linked to the type A flowering cycle.     

4种植物生长调节剂对夏黑葡萄拉长花序的效果

在夏黑葡萄开花前15天前后,研究喷施4种植物生长调节剂对花序的拉长效果。结果表明,以85%赤霉酸13.0mg/L、85%赤霉酸15.0mg/L、美国奇宝(20%赤霉酸)15000倍液、美国奇宝17500倍液处理的效果较好,4个处理间差异不显著,花序伸长较为明显,且无明显的畸形花序。疏果时用工量少,节省劳动力,太大的花序剪两端留中间即可。其中以85%赤霉酸15.0mg/L的效果最好,花序净拉长18.38cm。     

The effect of emasculation on the endogenous cytokinin levels of cymbidium flowers

Removal of the pollinaria and anther caps of cymbidium flowers resulted in anthocyanin accumulation in the lips and columns of the flower, followed by the senescence of petals and sepals. These changes correlated well with a decrease in the endogenous cytokinin levels in all parts of the flowers after emasculation. While it is presently not known how senescence is initiated, it is significant that at least 6 different cytokinins appear to be present in the anthers and that the total cytokinin level of these structures is much higher than in the rest of the cymbidium flower. This in itself may have an important function in preventing the onset of senescence.     

Micro-propagation of strawberry plants in vitro — Effect of growth regulators on incidence of multi-apex abnormality

A morphological abnormality occurring in micro-propagated strawberry plants is described and illustrated. The condition is recognised in established micro-propagated plants by an abnormal phyllotaxy which results typically in 2 or more young leaves emerging together rather than singly and by an excessive number of small branch crowns being produced. Dissection shows that the abnormality originates at the apex and is manifest as a linear (or less often as a circular) arrangement of multiple apices. Such multi-apexing plants “bud-off” normal single-apexed crowns from time to time but the abnormality can persist in the main shoot for 2 years (the limit of our observations). The multi-apexing differs fundamentally from clusters of single apices which, when removed from culture and separated, give rise to normal single-crowned plants.Similarities between the multi-apexing condition and fasciation in other plant species are discussed. Changes in growth regulator constituents of the culture media are shown to control the incidence of multi-apexing. In the presence of indole-3-butyric acid (IBA), higher 6-benzyl-aminopurine (BA) concentration increases the frequency, while adding gibberellin (GA₃) decreases the incidence of affected plantlets. The frequency of abnormality varies greatly between different cultivars.It is suggested that conditions favouring greater proliferation rates in culture may also favour multi-apexing. Results indicate that multi-apexing can be avoided by using appropriate concentrations of growth regulators in culture media which will concomitantly maintain a good proliferation rate.     

Effect of photoperiod and light integral on flowering and growth of Eustoma grandiflorum (Raf.) Shinn.

The aim of the study was to examine the effects of different photoperiod and light integral on floral initiation, development and subsequent growth of Eustoma grandiflorum (Raf.) Shinn. Six-weeks-old seedlings of ‘Echo Blue’ and ‘Fuji Deep Blue’ were placed under short day (SD, 10 h) and were transferred to long days (LD, 20 h) at 2-week intervals from 6 to 14 weeks after seeding. Plants initiated flower buds regardless of light regimes. Flower bud initiation was delayed by SD compared to LD; plants transferred after 6 weeks from seeding initiated flower buds at least 21 and 10 days earlier at LD at high (HL) and low (LL) daily light integral, respectively, compared to those at SD. Light regimes had little or no effect on time to flower bud development after initiation. Thus, it seems likely that LD and HL affected the initiation rather than development. Both the photoperiod and light integral strongly influenced the subsequent growth after initiation. SD delayed the time to visible bud (VB), increased the number of nodes to first open flower, number of branches, stem diameter and shoot dry weight compared to LD. HL promoted flowering and increased several shoot characteristics and flowering compared to LL.The results indicate that Eustoma is a quantitative long-day plant. LD, and more specifically HL, enhanced flower bud initiation, development and subsequent growth. An initial SD period is preferred to increase the number of branches, number of flowering buds and flowers, stem diameter and shoot dry weight.     

Effect of some growth regulators on sex expression of Momordica charantia L.

Gibberellin (GA), benzyladenine (BA), and maleic hydrazide (MH) promoted formation of female flowers in Momordica charantia L. GA was most effective. Low concentration of 2-chloroethyl trimethyl ammonium chloride (CCC) showed femineity, whereas high concentration showed a masculinizing effect. The effects of different concentrations of GA, BA, MH and CCC on flowering and sex expression are discussed. GA should not be considered as a general male sex hormone for all cucurbits.     

Effect of light wavelength on growth and flowering of narcissi forced under short-day and low quantum irradiance conditions

Summary

Four narcissus cultivars were forced under artificial light using fluorescent lamps which emitted white (307 – 770 nm), blue (393 – 580 nm), red (540 – 760 nm), yellow (450 – 750 nm), or green (387 – 680 nm) light. The photosynthetic photon flux density was 12.5 μmol m^–2 s^–1, with a 6 h photoperiod. Light colour (wavelength) had no significant effect on flowering date, or on the number of flowers collected (P < 0.05). Narcissus bulbs exposed to blue light (393 – 580 nm) formed shorter, more rigid shoots of lower weight with 13 – 40% shorter leaves.     

Effect of day and night temperatures during short photoperiods on growth and flowering of Chrysanthemum morifolium Ramat

The effect of day and night temperatures of 10, 14 and 18°C on growth and flowering under short days was studied with six cultivais of chrysanthemum. A high day temperature resulted in earlier flowering and taller stems, but did not influence flower number and final total fresh weight, and only slightly influenced the distribution of fresh matter over stem, leaves and flowers. A high night temperature resulted in earlier flowering, more flowers and reduced stem and leaf weight. It did not affect leaf number and it influenced height and total fresh weight only slightly. Except for height, the day temperature acted independently from the night temperature. The cultivars responded similarly, except for two cultivars which generally did not flower at 10/10,10/14 and 14/10°C D/N. One cul-tivar produced more flowers at 14 than at 18°C.     

Effect of temperature on flowering in Primula vulgaris

When grown in a glasshouse, flowering in Primula vulgaris ‘Aalsmeer Giant’ (yellow) and ‘Ducat’ (blue) was delayed with increasing temperature from approximately 12°C to 18°C. In addition, size of the first open flower and the number of flowering axillary shoots decreased, whereas the number of leaves and leaf area increased with the temperature increase. All temperature responses were greater in ‘Aalsmeer’ than in ‘Ducat’.When grown in growth rooms at 9°C, flowering in P. vulgaris ‘Aalsmeer Giant’ (yellow) was inhibited compared with 15°C. However, when 9 weeks of 15°C was applied to plants grown for 9 weeks at 9°C, the inhibition was overcome; longer periods of 15°C being no more effective. This indicates than an early stage of flower formation, probably the initiation, in Primula vulgaris is inhibited by 9°C, and not the further development of the buds towards open flowers.