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 ◽  
...  

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.

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 532
Author(s):  
Endre Kentelky ◽  
Zsolt Szekely-Varga ◽  
János Bálint ◽  
Adalbert Balog

Ornamental plants are cultivated worldwide. Chrysanthemum is classified as one of the most important cut and potted flowers in most of the countries. The consumer’s expectation is to find small–compact, and full of inflorescences plants. To meet these demands, growers are tending to use plant growth retardants. Three Chrysanthemum indicum L. varieties (‘Smola White’, ‘Arber’ and ‘Vienna White’) were assessed by using four plant growth regulators (PP–Bumper 250 EC; CC–Stabilan SL; MP–Medax Top SC; and PD–Toprex SC). Results indicate that treated plants show significant decrease in the assessed parameters, although in some cases growth could be a variety–dependent factor. It can also be concluded that retardants inhibit chrysanthemum growth. PD treatments greatly inhibited the growth of the plant, and also had a negative effect on inflorescences. In conclusion, the present work strengthens the possibility of using retardants as plant growth inhibitors in Chrysanthemum cultivation.


2003 ◽  
Vol 13 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Ryan M. Warner ◽  
John E. Erwin

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)).


HortScience ◽  
2015 ◽  
Vol 50 (9) ◽  
pp. 1370-1374 ◽  
Author(s):  
Iftikhar Ahmad ◽  
Brian E. Whipker ◽  
John M. Dole

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.


2019 ◽  
Vol 20 (13) ◽  
pp. 3307 ◽  
Author(s):  
Yanhai Ji ◽  
Guanxing Chen ◽  
Xuyang Zheng ◽  
Qiwen Zhong ◽  
Mingyun Zhang ◽  
...  

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.


2001 ◽  
Vol 19 (3) ◽  
pp. 145-149
Author(s):  
T.J. Banko ◽  
M.A. Stefani ◽  
M.S. Dills

Abstract In a 1999 experiment, Salvia x sylvestris ‘May Night’ and Scabiosa columbaria ‘Butterfly Blue’ were treated with the following plant growth retardants (PGRs) or PGR mixes: B-Nine (daminozide) at 5000 ppm (applied twice); B-Nine at 5000 ppm + Cycocel (chlormequat chloride) at 1500 ppm; Florel (ethephon) at 500 ppm (applied twice); B-Nine at 5000 ppm + Florel at 500 ppm; Sumagic (uniconazole) at 20 ppm; or B-Nine at 5000 ppm + Sumagic at 10 ppm. B-Nine effectively suppressed growth of salvia but not scabiosa, while Florel was effective on both salvia and scabiosa. However, Florel delayed flowering of both species by about 10 days. Sumagic at 20 ppm suppressed growth of scabiosa but not salvia. The PGR combination treatments, in general, were no more effective, and frequently less effective than the more effective PGR for a given species applied alone. In 2000 Florel was applied once to both salvia and scabiosa at 0, 250, 500, 750, and 1000 ppm. B-Nine (5000 ppm) was also applied to salvia, and Sumagic (20 ppm) was applied to scabiosa. Plant height of salvia was suppressed linearly with increasing Florel concentrations up to 42 days after treatment (DAT). Salvia also responded with a linear increase in inflorescence numbers at 32 and 42 DAT. Florel suppressed the height of scabiosa ‘Butterfly Blue’ linearly up to 52 DAT without affecting the initial number of inflorescences. When the first set of inflorescences was removed and a second set developed, there was a linear increase in inflorescence numbers with increasing concentrations of Florel.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Xiaodeng Shi ◽  
Siyu Chen ◽  
Zhongkui Jia

The effects of varieties, concentrations, and number of applications of plant growth retardants (PGRs) on the morphological, physiological, and endogenous hormones of Magnolia wufengensis L.Y. Ma et L. R. Wang were assessed to obtain the most suitable dwarfing protocol for M. wufengensis and to provide theoretical support and technical guidance for the cultivation and promotion of this species. One-year-old M. wufengensis ‘Jiaohong No. 2’ grafted seedlings served as the experimental materials. In the first part of the experiment, three PGRs (uniconazole, paclobutrazol, prohexadione calcium), three concentrations (500, 1000, 1500 ppm), and three applications (one, three, and five applications) were applied in dwarfing experiments to perform L9 (34) orthogonal tests. In the second part of the study, dwarfing experiments were supplemented with different high uniconazole concentrations (0, 1500, 2000, 2500 ppm). Spraying 1500 ppm uniconazole five times achieved the best M. wufengensis dwarfing effect, related indicators of M. wufengensis under this treatment were better than other treatment combinations. Here, M. wufengensis plant height, internode length, scion diameter, and node number were significantly reduced by 56.9%, 62.6%, 72.8%, and 74.4%, respectively, compared with the control group. This treatment increased superoxide dismutase (SOD) activity by 66.0%, peroxidase (POD) activity by 85.0%, soluble protein contents by 43.3%, and soluble sugar contents by 27.6%, and reduced malondialdehyde (MDA) contents by 32.1% in leaves of M. wufengensis compared with the control. The stress resistance of M. wufengensis was enhanced. The treatment also reduced gibberellin (GA3) levels by 73.0%, auxin (IAA) by 58.0%, and zeatin (ZT) by 70.6%, and increased (abscisic acid) ABA by 98.1% in the leaves of M. wufengensis. The uniconazole supplementation experiment also showed that 1500 ppm was the optimal uniconazole concentration. The leaves exhibited abnormalities such as crinkling or adhesion when 2000 or 2500 ppm was applied. Given the importance of morphological indicators and dwarfing for the ornamental value of M. wufengensis, the optimal dwarfing treatment for M. wufengensis was spraying 1500 ppm uniconazole five times.


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