scholarly journals The influence of growth retardants and cytokinins on flowering of ornamental plants

2012 ◽  
Vol 61 (1) ◽  
pp. 137-141 ◽  
Author(s):  
Anna Pobudkiewicz
Keyword(s):  
Growth Regulator ◽  
Stem Elongation ◽  
Ornamental Plants ◽  
Foliar Spray ◽  
Growth Retardants ◽  
Flower Buds ◽  
Axillary Shoots ◽  
Open Flower ◽  
Pedicel Length ◽  
Flower Diameter

Growth retardants are applied in order to obtain short and well compact plants. They usually inhibit stem elongation, but also can influence the flowering of plants. The aim of cytokinin application is to obtain well branched plants without removing the apical meristem. Cytokinins usually increase the number of axillary shoots but also can influence flowering. Growth retardants and cytokinins can affect flower size, pedicel length, number of flowers, flower longevity, abortion of flower buds and number of days from potting plants to the first open flower. Flowering of growth retardant and cytokinin treated plants might depend on the method of growth regulator used (foliar spray or soil drench), plant species or even a plant cultivar, but in the highest degree it depends on the growth regulator rate used. These growth regulators, when are applied at rates appropriate for height and habit control, very seldom influence flowering of ornamental plants, but applied at high rates can delay flowering, diminish flower diameter or flower pedicel length and also can decrease the number of flowers per plant. In cultivation of bulb plants, growth retardants, used at very high rates, also cause abortion of flower buds.

scholarly journals Paclobutrazol or Ancymidol Effects on Postharvest Performance of Potted Ornamental Plants and Plugs

HortScience ◽  
2015 ◽  
Vol 50 (9) ◽  
pp. 1370-1374 ◽  
Author(s):  
Iftikhar Ahmad ◽  
Brian E. Whipker ◽  
John M. Dole
Keyword(s):  
Plant Growth ◽  
Shelf Life ◽  
Stem Elongation ◽  
Ornamental Plants ◽  
Growth Control ◽  
Foliar Spray ◽  
Dry Weight ◽  
Growth Retardants ◽  
Potted Plants ◽  
Plant Growth Retardants

Effects of paclobutrazol and ancymidol on postharvest performance and growth control of potted sunflower (Helianthus annuus L.), zinnia (Zinnia elegans Jacq.) and marigold (Tagetes erecta L.), petunia (Petunia ×hybrida Vilm.) plugs, respectively, were studied. Paclobutrazol was applied as a drench at 0, 1.0, 2.0, or 4.0 mg of a.i. per 15.2-cm pot for sunflower and 0, 0.5, 1.0, or 2.0 mg per 12.5-cm pot for zinnia, while ancymidol was applied at 0, 40, 80, and 160 mg·L−1 with a volume of 0.21 L·m−2 as a foliar spray for marigolds or petunia plug crops. With an increase in paclobutrazol dose or ancymidol concentration, plant growth (plant height and diameter, shoot fresh or dry weight) was controlled for all species tested. Use of 1.0–2.0 mg paclobutrazol per pot produced 21% to 28% shorter plants with 12% to 15% smaller plant diameter, 13% to 19% less shoot fresh weight, 15% to 21% less dry weight, and darker green foliage color for potted sunflower than nontreated plants. Treatment with 1.0–4.0 mg paclobutrazol per pot delayed first wilting by 0.7–1.4 days compared with nontreated plants. For zinnia, 0.5–1.0 mg paclobutrazol controlled plant growth, produced dark green foliage, and extended shelf life by delaying first wilting by 2.6–3.9 days and second wilting by 1.4–2.0 days than nontreated plants. For marigold and petunia plugs, 40–80 mg·L−1 ancymidol provided ample growth control with darker green foliage; however, postharvest longevity was extended only when plugs were sprayed with 160 mg·L−1 ancymidol. During simulated storage and shipping, plant growth retardants maintained darker green foliage for potted sunflower, zinnia, and marigold plugs and prevented postharvest stem elongation of petunia plugs. In summary, use of plant growth retardants effectively controlled excessive plant growth and extended shelf life of potted plants and plugs.

scholarly journals Early Flurprimidol Drench Applications Suppress Final Height of Four Poinsettia Cultivars

2011 ◽  
Vol 21 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Christopher J. Currey ◽  
Roberto G. Lopez
Keyword(s):  
Stem Elongation ◽  
Final Height ◽  
Foliar Spray ◽  
Euphorbia Pulcherrima ◽  
Growth Retardants ◽  
Height Ratio ◽  
Chlormequat Chloride ◽  
Area Index ◽  
Aesthetic Appearance ◽  
Plant Growth Retardants

Plant growth retardants (PGRs) are commonly applied to control poinsettia (Euphorbia pulcherrima) stem elongation to meet a target final height. Two weeks after pinching, 4-fl·oz substrate drenches containing 0.0, 0.05, 0.10, 0.15, 0.20, or 0.25 mg·L−1 flurprimidol were applied to high-vigor ‘Orion’ and low-vigor ‘Polly Pink’ poinsettia (Expt. I); while drenches containing 0.0, 0.05, 0.10, or 0.15 mg·L−1 flurprimidol or a foliar spray containing 1250 mg·L−1 daminozide and 750 mg·L−1 chlormequat chloride were applied to high-vigor ‘Classic Red’ and low-vigor ‘Freedom Salmon’ poinsettia (Expt. II). Final height of ‘Orion’ and ‘Polly's Pink’ poinsettia was suppressed by 12% to 25% and 13% to 30%, respectively, as flurprimidol concentration increased from 0.05 to 0.25 mg·L−1. Final height of ‘Classic Red’ and ‘Freedom Salmon’ was suppressed by 11% to 30% and 10% to 19%, respectively, as flurprimidol concentration increased from 0.05 to 0.15 mg·L−1. Although the daminozide and chlormequat chloride spray had no significant effect on bract area index compared with untreated plants, bract area index was smaller for all plants treated with flurprimidol. However, the bract area to height ratio of all cultivars was not impacted by any PGR application, indicating aesthetic appearance was not negatively affected with smaller bract area. Time to anthesis was delayed by up to 4 days when 0.10 mg·L−1 was applied to ‘Classic Red’, although no significant delays were observed for the remaining cultivars. Based on these results, flurprimidol may be applied as an early drench to suppress height of poinsettia without adversely impacting finished plant quality or crop timing.

scholarly journals Physalis size reduction for potted ornamental plant use

2016 ◽  
Vol 40 (5) ◽  
pp. 555-564 ◽  
Author(s):  
Emily Bosch ◽  
Francine Lorena Cuquel ◽  
Grasiela Bruzamarello Tognon
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Ornamental Plants ◽  
Foliar Spray ◽  
Ornamental Plant ◽  
Plant Use ◽  
Potted Plant ◽  
Physalis Angulata ◽  
Plant Acceptability

ABSTRACT The consumer's constant search for novelties in the area of ornamental plants has inspired the use of species that are normally used for other purposes, such as fruit-bearing plants, to be introduced into floriculture. The physalis, a fruit-bearing plant, with a beautiful accrescent fruiting calyx that envelops the berry, can be used for these purposes. However, this plant can reach 70 cm high, which makes it unviable to be used as an indoor plant. The objective of this research was to decrease the size of the physalis (Physalis angulata) for ornamental use, pot it and apply the plant growth regulator Paclobutrazol (PBZ). The PBZ growth regulator was applied only once, via foliar spray at the concentrations of 0, 30, 60, 90, 120 and 150 mg a.i L- 1, as well as via irrigation in the substrate at concentrations of 0, 5, 10, 15, 30 and 60 mg a.i L- 1. Along with the quantitative variables, a plant acceptability test was carried out when it was considered ideal for commercialization. The obtained results clearly show that it is possible to reduce the size of the physalis for use as a potted plant by using PBZ with foliar applications at the concentration of 90 mg a.i L-1 or by using irrigation applications directly in the substrate at a concentration of 5 mg a.i L-1.

scholarly journals Bulking Duration and Daminozide Affect Growth and Flowering of Achillea בCoronation Gold’

2015 ◽  
Vol 33 (2) ◽  
pp. 84-88
Author(s):  
Mohan Li ◽  
J. Raymond Kessler ◽  
Gary J. Keever ◽  
Wheeler G. Foshee
Keyword(s):  
Plant Growth ◽  
Foliar Spray ◽  
Growth Retardant ◽  
Main Stem ◽  
Stem Length ◽  
Flower Buds ◽  
Flower Bud ◽  
Open Flower ◽  
Single Shoot

A study was conducted to determine the effects of bulking duration and the plant growth retardant daminozide on plant growth and flowering of greenhouse-grown ‘Coronation Gold’ yarrow (Achillea בCoronation Gold’). Single-shoot liners of yarrow were transplanted on October 14 and December 2, 2010, into 15 cm (6 in) containers and bulked for 4, 6, 8, or 10 weeks prior to exposure to night-interrupted lighting (NIL). Increasing the bulking duration increased the number of shortened, thickened stems of rosette-like appearance, or offsets, that had developed from the base of the main stem by the end of bulking by 100 to 367% and reduced days to first and five open inflorescences, hereafter referred to as flowers, from the beginning of NIL by 13 to 16 days and 10 to 20 days for the October and December potting dates, respectively. Increasing the bulking duration increased flower and flower bud number by 67 and 25% in the October 14 and December 2 potting dates, respectively. Therefore, more flowers and flower buds formed on yarrow when potted early, compared to late potting. Lengths of the first five open flower stems were inconsistent and minimally affected by bulking duration. In a repeat of the experiment potted on December 2 using the same bulking treatments, 5,000 ppm of daminozide was applied as a foliar spray when half the plants in a bulking duration had begun to elongate and was reapplied 1 week later. Daminozide application decreased stem length at first open flower by 20 to 43%, but increased days to first flower and five open flowers by 6 and 8 days, respectively. As in the first experiment, increasing the bulking duration increased the number of offsets and flower and flower bud number and reduced days to first and five open flowers.

scholarly journals Growth retardants on development and ornamental quality of potted 'Lilliput' Zinnia elegans Jacq.

2005 ◽  
Vol 62 (4) ◽  
pp. 337-345 ◽  
Author(s):  
Ana Christina Rossini Pinto ◽  
Teresinha de Jesus Deléo Rodrigues ◽  
Izabel Cristina Leite ◽  
José Carlos Barbosa
Keyword(s):  
Low Cost ◽  
Foliar Spray ◽  
Zinnia Elegans ◽  
Experimental Unit ◽  
Production Cycle ◽  
Growth Retardants ◽  
Flower Bud ◽  
Potted Plants ◽  
Flower Diameter ◽  
Set Up

Zinnias have good potential to be used as flowering, potted plants, being a quick source of novelty for the floriculture industry with the aid of growth retardants. This study evaluated the effect of growth retardants on development and production of short, compact and attractive plants of potted 'Lilliput' Zinnia elegans, a highly ornamental zinnia with low cost seeds. Trials were set up in randomized blocks, with ten treatments (control and three treatments of each retardant: daminozide, paclobutrazol and chlormequat) and four replications (two pots per experimental unit, with one plant per 0.6-L pot). Paclobutrazol (0.5, 0.75 and 1.0 mg a.i. per pot) and chlormequat (1.0, 2.0 and 3.0 g L-1) were applied as a single drench (40 mL per pot), and daminozide (2.5, 3.75 and 5.0 g L-1) as a single foliar spray to runoff (10 mL per pot), at apical flower bud stage. Daminozide (2.5 and 3.75 g L-1), paclobutrazol (0.5, 0.75 and 1.0 mg a.i. per pot) and chlormequat at 1.0 g L-1 significantly reduced plant height and side branches length, without affecting flower diameter, delaying production cycle and causing phytotoxicity symptoms. However, plants were not short and compact enough to meet market quality demand. Chlormequat (2.0 and 3.0 g L-1) caused phytotoxicity symptoms and daminozide (5.0 g L-1) delayed production cycle.

scholarly journals Growth Regulator Effects on Development of Three Bedding Plant Plugs

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 509B-509
Author(s):  
C.E. Wieland ◽  
J.E. Barrett ◽  
C.A. Bartuska ◽  
D.G. Clark ◽  
T.A. Nell
Keyword(s):  
Catharanthus Roseus ◽  
Growth Regulator ◽  
Stem Elongation ◽  
Plant Size ◽  
Application Time ◽  
Growth Retardants ◽  
Single Application ◽  
Time Interaction ◽  
Salvia Splendens ◽  
Bedding Plant

Salvia (Salvia splendens F.), vinca (Catharanthus roseus L.), and pansy (Viola × wittrockiana Gams.) were examined to determine efficacy of growth retardants for inhibiting stem elongation of seedlings in the plug stage and after transplanting to 10-cm pots. Studies on salvia showed plugs sprayed with single applications of ancymidol at 10 or 20 ppm, paclobutrazol at 30 or 60 ppm, or daminozide/chlormequat tank mix at 2500/1500 ppm inhibited plug elongation by 17% to 22%. Pansy plugs were sprayed either once or twice with ancymidol at 5, 10, or 15 ppm. Number of applications was statistically significant with two applications reducing elongation by an average of 35%, whereas a single application resulted in a 23% average reduction. Ancymidol concentration was significant in reducing stem elongation with increasing rates in pansy; however, the concentration and application time interaction was not significant. In both pansy and salvia, plant size at flowering was similar to controls after transplanting. Vinca plugs were sprayed with ancymidol at 5, 10, or 15 ppm either the 3rd week, 4th week, or both weeks after sowing. As ancymidol concentrations increased, plug height decreased, and the concentration effect was greater week 3 than at week 4. Two applications of ancymidol was most effective in retarding stem elongation (36%) followed by one spray the 3rd week (29%) and one spray during week 4 (20%).

Potted platycodon production in response to paclobutrazol

2021 ◽  
Vol 51 ◽  
Author(s):  
João Henrique Ferreira Sabino ◽  
José Antonio Saraiva Grossi ◽  
Toshik Iarley da Silva ◽  
Otávio Miranda Verly ◽  
Sebastião Martins Filho ◽  
...  
Keyword(s):  
Leaf Area ◽  
Stem Elongation ◽  
Dry Mass ◽  
Shoot Length ◽  
Flower Buds ◽  
Flower Diameter ◽  
Number Of Leaves ◽  
Higher Doses ◽  
Ornamental Species

ABSTRACT Platycodon grandiflorus is an ornamental species that can be marketed as a potted flower; however, it has fragile and bending floral stems. Plant growth regulators, such as paclobutrazol, are compounds that reduce stem elongation, enabling the production of plants with a more compact formation. This study aimed to evaluate the effects of paclobutrazol on platycodon growth, in a greenhouse. A completely randomized blocks experimental design was used in a 4 × 5 factorial scheme, with four replicates. The treatments consisted of four varieties of ‘Astra Semi-Double’ platycodon (Blue, Lavender, Pink and White) and five paclobutrazol doses (0, 1.25, 2.5, 3.75 and 5.0 mg pot-1). The paclobutrazol application did not affect the stem diameter, number of leaves, days until anthesis, number of flowers or flower buds, and flower diameter. The shoot length, leaf area and shoot dry mass decreased with higher doses of the growth regulator. Lavender showed the highest values for shoot length, number of leaves, leaf area and shoot dry mass. Pink had the earliest anthesis, followed by Blue and White, whereas Lavender had the latest anthesis. The dose of 3.75 mg pot-1 of paclobutrazol efficiently controlled the growth and improved the visual quality of all the platycodon varieties.

scholarly journals Coreopsis grandiflora `Sunray' Flowers in Response to Short Days or Vernalization

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1100A-1100
Author(s):  
Sonali Padhye ◽  
Erik S. Runkle ◽  
Arthur Cameron
Keyword(s):  
Plant Height ◽  
Leaf Development ◽  
Flower Buds ◽  
Flower Bud ◽  
Axillary Shoots ◽  
Open Flower ◽  
Subsequent Flowering ◽  
Vegetative Cuttings ◽  
Photoperiod Control ◽  
Short Days

Coreopsis grandiflora `Sunray' has been reported to flower under long days (LD) following vernalization or short days (SD). The objectives of this study were to characterize the effective duration of vernalization and SD and to determine if photoperiod during vernalization influences flowering. Vegetative cuttings taken from stockplants developed from one seedling were rooted for 2 weeks and grown for 5 weeks. Plants were provided with a 9-hour photoperiod for 2, 4, 6, or 8 weeks or were vernalized at 5 °C under a 16-hour photoperiod for 2, 4, 6 or 8 weeks or under a 9-hour photoperiod for 2 or 8 weeks. Following treatments, plants were grown in a greenhouse at 20 °C under a 16-hour photoperiod. Control plants were grown under constant 9- or 16-hour photoperiod. Leaf development, days to first visible bud (DVB), days to first open flower (DFLW), and height and total number of flower buds at FLW were recorded. No plants flowered under continuous SD. Under continuous LD, two plants flowered on axillary shoots but only after 95 days. All vernalized and SD-treated plants flowered on both terminal and axillary shoots. Photoperiod during vernalization did not affect subsequent flowering. DFLW decreased from 56 to 42 and from 50 to 42 after 2 to 8 weeks of vernalization and SD treatments, respectively. Following 2, 4, 6, and 8 weeks of vernalization, plants had 116, 116, 132, and 204 flower buds, respectively. Plant height at FLW of all SD-treated and vernalized plants was similar. Thus, 2 weeks of 9-hour SD or vernalization at 5 °C followed by LD was sufficient for flowering of our clone of C.`Sunray', although longer durations hastened flowering and increased flower bud number.

scholarly journals GROWTH RETARDANTS effects ON FLOWERING AND YIELD PARAMETERS OF SPANISH JASMINE (Jasminum grandiflorum L.)

1970 ◽  
pp. 01-03
Author(s):  
R. SUDHAGAR, S. KAMALAKANNAN
Keyword(s):  
Shelf Life ◽  
Block Design ◽  
Foliar Spray ◽  
Growth Retardants ◽  
Flower Buds ◽  
Flower Bud ◽  
Flower Stalk ◽  
Yield Attributes ◽  
Yield Parameters ◽  
Randomized Block Design

An experiment was conducted to study the effect of growth retardants on flowering and yield parameters and shelf life of spanish jasmine. The experiment comprised of eleven treatments each replicated thrice was executed following the principles of randomized block design. The treatments included foliar spray of CCC @ 1000, 1500 and 2000 ppm, alar @ 1000, 2000 and 3000 ppm, ethrel @ 1000, 1500 and 2000 ppm, pruning and untreated control. In this study, the application of CCC 1500 ppm exerted favourable influence and enhanced the flower bud characters viz., flower bud length (2.98 cm), flower stalk length (2.36 cm) and total length of the flower (5.34 cm). The yield and yield attributes viz., hundred flower buds weight (9.90 g), flower buds yield plant-1 (4.23 kg), flower buds yield plot-1 (33.84 kg) and flower buds yield hectare-1 (14.1 t ha-1) were also found to be the maximum in the plants treated with CCC 1500 ppm. The plant growth retardants did not show any significant effect on shelf life of flowers.

Long-term Effects of Triazol Growth Regulators on Stem Elongation of Rhododendron and Kalmia

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 436E-436
Author(s):  
Martin P.N. Gent
Keyword(s):  
Dose Response ◽  
Growth Regulator ◽  
Stem Elongation ◽  
Spray Application ◽  
Long Term Effects ◽  
Potted Plants ◽  
Response Coefficient ◽  
Wide Range ◽  
Second Year

The persistence of effects of paclobutrazol or uniconazol on stem elongation was determined for several years after large-leaf Rhododendron and Kalmia latifolia were treated with a single-spray application of these triazol growth-regulator chemicals. Potted plants were treated in the second year from propagation, and transplanted into the field in the following spring. The elongation of stems was measured in the year of application and in the following 2 to 4 years. Treatments with a wide range of doses were applied in 1991, 1992, or 1995. For all except the most-dilute applications, stem elongation was retarded in the year following application. At the highest doses, stem growth was inhibited 2 years following application. The results could be explained by a model of growth regulator action that assumed stem elongation was inversely related to amount of growth regulator applied. The dose response coefficient for paclobutrazol was less than that for uniconazol. The dose that inhibited stem elongation one-half as much as a saturating dose was about 0.5 and 0.05 mg/plant, for paclobutrazol and uniconazol, respectively. The dose response coefficient decreased exponentially with time after application, with an exponential time constant of about 2/year. The model predicted a dose of growth regulator that inhibited 0.9 of stem elongation immediately after application would continue to inhibit 0.5 of stem elongation in the following year.

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