scholarly journals Effect of Plant Growth Retardants on Stem Elongation of Hibiscus Species

2003 ◽  
Vol 13 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Ryan M. Warner ◽  
John E. Erwin
Keyword(s):  
Plant Growth ◽  
Stem Elongation ◽  
Stem Length ◽  
Growth Retardants ◽  
Chlormequat Chloride ◽  
Plant Growth Retardants ◽  
Butanedioic Acid ◽  
Spray Applications

One-time spray applications [about 6 mL (0.2 fl oz)] of chlormequat chloride [1000 or 2000 mg·L-1 (ppm)], daminozide (2500 or 5000 mg·L-1), paclobutrazol (20 or 40 mg·L-1) and uniconazole (5 or 10 mg·L-1) varied in efficacy in reducing Hibiscus coccineus (Medic.) Walt., H. radiatus Cav., and H. trionum L. (flower-of-an-hour) stem elongation. Chlormequat chloride inhibited stem elongation of all species, with a 2000 mg·L-1 application reducing stem length of H. coccineus, H. radiatus, and H. trionum by 87%, 42%, and 52%, respectively, compared to untreated plants, 28 d after application. Paclobutrazol also inhibited stem elongation of all species. Uniconazole reduced stem elongation of H. coccineus and H. radiatus, but not H. trionum. Daminozide applied at 5000 mg·L-1 reduced H. radiatus stem elongation only. Growth retardants examined in this study did not delay flowering of H. trionum, the only species that flowered during the experiment. (Chemical names used: ancymidol (α-cyclopropyl-α-(4-methoxyphenol)-5-pyrimidinemethonol), chlormequat chloride(2-chloroethyltrimethylammonium chloride), paclobutrazol ((+)-(R*,R*)-beta((4-chlorophenyl)methyl)-alpha-(1,1-dimethyl)-1H-1,2,4-triazol-1-ethanol), daminozide ([butanedioic acid mono(2,2-dimethylhydrazide)], uniconazol-P ((E)-(+)-(s)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pent-1-ene-3-ol)).

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 Growth Retardants Affect Growth and Flowering of Scaevola

HortScience ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 36-38 ◽  
Author(s):  
Terri W. Starman ◽  
Millie S. Williams
Keyword(s):  
Phosphonic Acid ◽  
The Other ◽  
Stem Length ◽  
Growth Retardants ◽  
Stem Number ◽  
Flower Number ◽  
Flower Stem ◽  
Butanedioic Acid ◽  
Delayed Flowering ◽  
Spray Applications

The effects of concentration and method of application of uniconazole on growth and flowering of Scaevola aemula R. Br. `New Wonder', `Mini Pink Fan', `Purple Fan', and `Royal Fan', Scaevola albida (Sm.) Druce. `White Fan', and Scaevola striata `Colonial Fan' were studied, as was the efficacy of four other growth retardants on S. aemula `New Wonder'. Variables measured included plant width, flower stem number, flower stem length, flower number per stem, flower number per cm stem length, and days to flower. Uniconazole (1.0 mg·L–1) applied as a medium drench to S. aemula `New Wonder' reduced plant width and flower stem length without affecting flower stem number or time to flower. Flower number per stem and number of flowers per cm of stem length were increased, resulting in attractive, compact clusters of flowers. Paclobutrazol medium drench at 4.0 mg·L–1 gave similar results. Daminozide and ethephon sprays reduced plant width; however, flower number was reduced and ethephon delayed flowering. Ancymidol did not affect the parameters measured. When uniconazole drenches were applied to the other cultivars, plant width and flower stem length in all cultivars except `White Fan' decreased as rate increased. Spray applications reduced plant width of all cultivars except `Mini Pink Fan'. Flower stem length was not affected in any cultivar. Flowering habit was improved more in S. aemula `New Wonder', `Purple Fan', and `Royal Fan' than in the other cultivars. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); (2-chloroethyl)phosphonic acid (ethephon); β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol); (E)-(s)-1-(4-chlorophenyl)-4,4-dimethy-2-(1,2,4-triazol-1-yl)-pent-1-ene-3-ol (uniconazole).

scholarly journals Foliar Applications of Plant Growth Regulators Affect Stem Elongation and Branching of 11 Kalanchoe Species

2012 ◽  
Vol 22 (3) ◽  
pp. 338-344 ◽  
Author(s):  
Christopher J. Currey ◽  
John E. Erwin
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Stem Elongation ◽  
Foliar Spray ◽  
Stem Length ◽  
Chlormequat Chloride ◽  
Branch Number ◽  
Time Of Application ◽  
Number Of Branches

Our objectives were to assess the efficacy of various plant growth regulators (PGRs) on stem elongation and branching of 11 kalanchoe (Kalanchoe) species with ornamental characteristics: beauvard’s widow’s-thrill (K. beauvardii), K. glaucescens, lavender scallops or red-leaved kalanchoe (K. fedtschenkoi), K. longiflora, chandelier plant (K. manginii), marnier’s kalanchoe (K. marnieriana), K. millotii, flower dust plant (K. pumila), K. rosei, common kalanchoe or nentabos (K. rotundifolia), and K. streptantha. Foliar spray applications of deionized water, ancymidol (15−60 ppm), benzyladenine (75−300 ppm), chlormequat chloride (750−3000 ppm), daminozide (1250−5000 ppm), ethephon (250−1000 ppm), paclobutrazol (10−40 ppm), or uniconazole (5−20 ppm) were applied 2 weeks after plants were pinched. Stem length at the time of application and 4 weeks after applications and branch number were recorded. While effective chemicals and concentrations varied widely among species, paclobutrazol and uniconazole were identified as providing broad efficacy with respect to inhibition of stem elongation across all 11 species in this study. Additionally, benzyladenine and ethephon increased the number of branches for several species.

scholarly journals Control of Salpiglossis sinuata Height with Plant Growth Regulators

HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 441-443
Author(s):  
Douglas C Needham ◽  
P. Allen Hammer
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Regulators ◽  
Vegetative Growth ◽  
Growth Retardants ◽  
Chlormequat Chloride ◽  
Potted Plant ◽  
Butanedioic Acid ◽  
Line P ◽  
Corolla Diameter

Salpiglossis sinuata R. et P., a floriferous member of the Solanaceae, was studied for potential as a flowering potted plant when modified by growth retardants. Seedlings of an inbred line P-5 were covered with black cloth for an 8-hour photoperiod to permit vegetative growth to ≈16 -cm-diameter rosettes. Plants were then exposed to an 18-hour photoperiod for the duration of study. Flowering occurred 40 days after the plants were transferred to long days. Neither spray applications of uniconazole at 10, 20, 40, or 100 ppm, nor chlormequat chloride at 750, 1500, or 3000 ppm significantly retarded plant height. Applications of daminozide, ranging in concentration from 1000 to 5000 ppm, alone and in combination with chlormequat chloride, were effective at retarding plant height; however, concomitant restriction of corolla diameter was frequently observed. Chemical names used: 2-chloro- N,N,N -trimethylethanaminium chloride (chlormequat chloride); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); and (E) -1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl) -1-penten-3-01 (uniconazole).

scholarly journals Effects of Plant Growth Retardants on Development of Poinsettia ”Christmas Feeling” Cultivar

2021 ◽  
Vol 4 (2) ◽  
pp. 32-38
Author(s):  
Artúr Botond Csorba ◽  
Mária Tatár ◽  
Erzsébet Buta ◽  
Katalin Molnár ◽  
Erzsébet Domokos ◽  
...  
Keyword(s):  
Plant Growth ◽  
Ornamental Plants ◽  
Cold Season ◽  
Recent Time ◽  
Growth Retardants ◽  
High Quality ◽  
Chlormequat Chloride ◽  
Plant Growth Retardants

Abstract The poinsettias were cultivated years ago as medicinal and ornamental plants, too; but in the recent time are in the light of world flower assortment surprising with new shapes and colors in the cold season. The ornamental values of these plants are given by bracts which can have the same size as foliage leaves or even larger. The tendency of floral industry consists in obtaining high quality ornamental plants with superior marketable price. In these regards, the role of plant growth retardants in regulating the growth of poinsettia is important to obtain healthy, compact bushes and extended decoration period. The aim of the paper is to evaluate the effects of plant growth retardants on poinsettia. Five treatments with different retardants were applied as drench or spray. In the experiment four replicates and a total of 144 poinsettias were used. Treatments with paclobutrazol (60 mg/l sprayed), daminozide (2500 mg/l sprayed) and chlormequat chloride (1000 mg/l sprayed), showed the best results in case of marketability.

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 Phosphorus Restriction as an Alternative to Chemical Plant Growth Retardants in Angelonia and New Guinea Impatiens

2018 ◽  
Vol 28 (2) ◽  
pp. 136-142
Author(s):  
Josh B. Henry ◽  
Ingram McCall ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Stem Elongation ◽  
Control Plant ◽  
Growth Index ◽  
New Guinea ◽  
Chemical Plant ◽  
Growth Retardants ◽  
P Deficiency ◽  
Plant Growth Retardants ◽  
New Guinea Impatiens

Chemical plant growth retardants (PGRs) are commonly used to produce compact bedding plants. Few PGRs are labeled for sensitive species because of the concern of excessive restriction of stem elongation or phytotoxicity. Growers are therefore presented with a dilemma: produce untreated plants that may be too tall or risk applying a PGR that can potentially lead to irreversible aesthetic damage to the plant. Nutrient restriction, specifically of phosphorus (P), may be used to control plant height. This study was conducted to determine if restricting P fertilization yielded comparable growth control to plants produced with PGRs. Two cultivars each of new guinea impatiens (Impatiens hawkeri) and angelonia (Angelonia angustifolia) were grown using five fertilizers that varied by P concentration (0, 2.5, 5, 10, and 20 ppm). Half of the plants from each P fertilizer concentration were treated with paclobutrazol at 4 and 5 weeks after transplant for angelonia and new guinea impatiens, respectively. On termination of the experiment, data were collected for height, diameter, and dry weight, which were used to determine a growth index (GI). Angelonia GI values were maximized with 7–9 ppm P, whereas new guinea impatiens GI was maximized with 8–11 ppm P. Concentrations of 3–5 ppm P provided similar height control to plants grown with nonlimiting P and a paclobutrazol application. Concentrations of ≤2.5 ppm P resulted in low-quality plants with visual symptoms of P deficiency. These results indicate that a narrow range of P concentrations may be used to control stem elongation and keep plants compact.

scholarly journals Comprehensive Transcriptome Reveals an Opposite Regulatory Effect of Plant Growth Retardants in Controlling Seedling Overgrowth between Roots and Shoots

2019 ◽  
Vol 20 (13) ◽  
pp. 3307 ◽  
Author(s):  
Yanhai Ji ◽  
Guanxing Chen ◽  
Xuyang Zheng ◽  
Qiwen Zhong ◽  
Mingyun Zhang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Transcriptome Profiling ◽  
Regulation Mechanism ◽  
Growth Retardants ◽  
Transcriptome Profile ◽  
Chlormequat Chloride ◽  
Ga Signaling ◽  
Plant Growth Retardants ◽  
First Time ◽  
Ga Biosynthesis

Seedling overgrowth always develops in undernourished plants due to biotic or abiotic stresses, which significantly decrease the yield of crops and vegetables. It is known that the plant growth retardants paclobutrazol (PBZ) and chlormequat chloride (CCC) are the most commonly used chemicals in controlling seedling height in plants by regulating the gibberellin (GA) biosynthesis pathway. However, the exact molecular regulation mechanism remains largely unknown. This study performed a comprehensive transcriptome profile to identify significantly differentially expressed genes after adding CCC and PBZ to the water culture seedling raising system for the first time. According to the obviously restrained shoots and roots, the GA biosynthesis genes were significantly decreased, as well as the endogenous GA content being reduced. Intriguingly, the GA signaling pathway genes were affected in opposite ways, increasing in roots but decreasing in shoots, especially regarding the phytochrome interacting factor SlPIF1 and the downstream genes expansins (SlEXPs), which promote cell wall remodeling. Further study found that the most down-regulated genes SlEXPA5 and SlEXPA15 were expressed specifically in shoot tissue, performing the function of repressing elongation, while the up-regulated genes SlEXPB2 and SlEXPB8 were proven to be root-specific expressed genes, which may promote horizontal elongation in roots. This research reported the comprehensive transcriptome profiling of plant growth retardants in controlling seedling overgrowth and restraining GA biosynthesis through the regulation of the GA signaling-related genes SlPIF1 and SlEXPs, with an opposite expression pattern between roots and shoots.

scholarly journals The Effect of Daminozide and Chlormequat on the Growth and Flowering of Poinsettia and Pansy

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1315-1318
Author(s):  
Kelly P. Lewis ◽  
James E. Faust ◽  
James D. Sparkman ◽  
Larry W. Grimes
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Stem Elongation ◽  
Euphorbia Pulcherrima ◽  
Trimethylammonium Chloride ◽  
Growth Responses ◽  
Chlormequat Chloride ◽  
Butanedioic Acid

Poinsettia (Euphorbia pulcherrima Willd. Ex Klotzch) `Freedom Red' (FR), `Success Red' (SR), and `Winter Rose Dark Red' (WRDR) and pansy (Viola wittrockiana Gams.) `Colossus Yellow Blotch' (CYB), `Delta Pure Yellow' (DPY), and `Majestic Giants Purple' (MGP) were treated with 14 different tank mix combinations of daminozide and chlormequat ranging from 0 to 4500 mg·L-1 daminozide and 0 to 1500 mg·L-1 chlormequat. The tank mix treatments reduced stem elongation for all three poinsettia cultivars. Total bract area of FR and canopy bract diameter of WRDR decreased linearly as daminozide or chlormequat concentration increased, while bract area of SR was affected by daminozide alone. Anthesis was not delayed by any of the plant growth regulator (PGR) applications. For pansies, growth responses to the PGR treatments varied with cultivar. CYB growth was affected by daminozide alone, DPY growth was affected by daminozide and/or chlormequat, while MGP growth was relatively insensitive to both PGRs. Time to flower of pansy was not affected by the PGR applications. Chemical names used: 2-chloroethyl N,N,N-trimethylammonium chloride (chlormequat chloride); butanedioic acid mono (2,2-dimethylhydrazide) (daminozide).

scholarly journals Controlled Water Deficit as an Alternative to Plant Growth Retardants for Regulation of Poinsettia Stem Elongation

HortScience ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 565-569 ◽  
Author(s):  
Peter Alem ◽  
Paul A. Thomas ◽  
Marc W. van Iersel
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Plant Height ◽  
Water Deficit ◽  
Stem Elongation ◽  
Alternative Methods ◽  
Growth Retardants ◽  
Target Height ◽  
Height Control ◽  
Plant Growth Retardants

Production of poinsettias (Euphorbia pulcherrima) often involves intensive use of plant growth retardants (PGRs) to regulate height. Height control is necessary for visual appeal and postharvest handling. Since PGRs do not always provide consistent height control and can have unwanted side effects, there is interest in alternative methods of height control. Since turgor potential drives cell expansion, and thus stem elongation, drought stress has potential for regulating plant height. Through soil moisture sensor-controlled irrigation, the severity of drought stress can be both monitored and controlled. The objective of our study was to compare poinsettia ‘Classic Red’ height control using PGRs (spray, mixture of daminozide and chlormequat at 1000 mg·L−1 each and drench, 0.25 mg·L−1 paclobutrazol) with the use of controlled water deficit (WD). Graphical tracking of plant height, using a final target height of 43.5 cm, was used to determine when to apply PGR or controlled WD. In the WD treatment, substrate volumetric water content (θ) was reduced from 0.40 to 0.20 m3·m−3 when actual height exceeded the expected height. PGR applications (spray or drench) reduced poinsettia height to 39 cm, below the final target level of 43.5 cm. WD resulted in a height of 44.5 cm, closest to the target height, while control plants were taller (49.4 cm). There was no effect of PGR drenches or WD on bract size, while spraying PGR reduced bract size by ≈ 40%. Bract chroma was unaffected by WD or PGR treatments. There was no difference in shoot dry weight between PGR- and WD-treated plants. Lateral growth was reduced by the PGR treatments, but not by WD. These results indicate that controlled WD can be used to regulate poinsettia height.

Sign in / Sign up

Export Citation Format

Share Document