Use of Trinexepac-ethyl for Growth Regulation of Chrysanthemum (Dendranthema ×grandiflora)

Trinexapac-ethyl (TE) [4-(cyclopropyl-α-hydroxy-methylene)-3, 5-dioxocyclohexanecarboxylic acid ethyl ester] is a plant growth regulator registered for use in turfgrass. The objective of the research reported in this paper was to determine if TE could be used in the production of florist chrysanthemums (Dendranthema ×grandiflora) to produce more compact, higher value plants. Foliar applications of TE to non-pinched plants of the tall cultivar `Billings' reduced canopy height 8% to 40% as the amount of applied TE was increased from 6.25 × 10–5 to 2.0 × 10–3 g. The effects of TE varied among chrysanthemum cultivars. Growth inhibition of pinched plants among the various cultivars ranged from 7% (`White Viewtime') to 23% (`White Graceland') 28 days following a single application of 1.0 × 10–3 g TE. In most cultivars, the inhibitory action of TE was not observed after 28 days. In fact some cultivars exhibited a rebound effect during the post-suppression growth phase in which internode extension rates were greater in TE-treated plants than controls. Both the number and timing of the TE application affected efficacy. A second TE application 5 weeks after the first treatment, or application of TE at the appearance of flower buds produced the highest quality crop in terms of uniformity and compactness, with overall height reduction generally 15% to 20%. No differences in flower color, number, or mass per flower were observed due to TE application.

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Self-assembly of 1-triacontanol onto Layered Doubled Hydroxide Nano-carrier toward Sustainable Growth Regulation of Maize

Environmental Science Nano ◽

10.1039/d1en00972a ◽

2022 ◽

Author(s):

Chong Wang ◽

Fei Gao ◽

Changjiao Sun ◽

Yue Shen ◽

Shenshan Zhan ◽

...

Keyword(s):

Seed Germination ◽

Plant Growth ◽

Root Growth ◽

Growth Regulator ◽

Self Assembly ◽

Plant Growth Regulator ◽

Growth Regulation ◽

Physiological Effect ◽

Sustainable Growth ◽

Considerable Research

1-triacontanol has attracted considerable research interest in plant growth regulator field, owing to its physiological effect in seed germination, root growth and photosynthesis enhancement. In this work, a 1-triacontanol modified...

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Encapsulation of Synthesized Plant Growth Regulator Based on Copper(II) Complex in Chitosan/Alginate Microcapsules

International Journal of Molecular Sciences ◽

10.3390/ijms22052663 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2663

Author(s):

Darikha Kudasova ◽

Botagoz Mutaliyeva ◽

Kristina Vlahoviček-Kahlina ◽

Slaven Jurić ◽

Marijan Marijan ◽

...

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Electrostatic Interactions ◽

Growth Regulation ◽

Profile Analysis ◽

Fickian Diffusion ◽

Controlling Mechanism ◽

High Concentrations ◽

Reduced Surface

A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations—0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture

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Growth Control of ‘Taylortown Red’ and ‘Homestead Purple’ Verbena with Pistill in Nursery Production

Journal of Environmental Horticulture ◽

10.24266/0738-2898-26.2.67 ◽

2008 ◽

Vol 26 (2) ◽

pp. 67-69

Author(s):

T.J. Banko ◽

M.A. Stefani

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Initial Treatment ◽

Growth Control ◽

Single Application ◽

Nursery Production ◽

Outdoor Nursery ◽

Spray Applications

Abstract Verbena canadensis ‘Homestead Purple’ and ‘Taylortown Red’ were treated with one or two spray applications of the plant growth regulator (PGR) Pistill (ethephon) at 0, 250, 500, 750, or 1000 ppm. Plants were in 3.8 liter (1 gal) containers under outdoor nursery conditions. Plant widths of ‘Homestead Purple’ verbena were suppressed linearly with increasing Pistill concentrations up to 24% at 2 weeks after initial treatment (WAT) and up to 18% at 4 WAT. Widths of ‘Taylortown Red’ verbena were suppressed 22% at 2 WAT with a single application at 500 to 1000 ppm, and linearly up to 33% at 4 WAT with 2 applications. Two applications of Pistill suppressed heights and widths of both cultivars at 7 WAT compared to one application.

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Growth Regulation and Tank Mixing Associated with a Glyphosate-tolerant Perennial Ryegrass Cultivar

HortTechnology ◽

10.21273/horttech.25.2.214 ◽

2015 ◽

Vol 25 (2) ◽

pp. 214-220

Author(s):

Christian M. Baldwin ◽

A. Douglas Brede ◽

Jami J. Mayer

Keyword(s):

Plant Growth ◽

Perennial Ryegrass ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Growth Regulation ◽

Management Strategies ◽

Additional Benefit ◽

Minimal Effect ◽

Annual Bluegrass ◽

N Sources

With the emergence of glyphosate-tolerant cultivars, identifying management strategies not applicable with older cultivars need to be revisited. Objectives of these research trials were to quantify the growth regulation effects following a glyphosate application and to determine the safety of tank mixing glyphosate with another herbicide, various nitrogen (N) sources, and a plant growth regulator (PGR) on a glyphosate-tolerant perennial ryegrass [PRG (Lolium perenne L.)] cultivar, Replay. In the growth regulation trial, glyphosate was applied at 0 to 1.03 lb/acre, whereas PGRs flurpimidol, trinexapac-ethyl, paclobutrazol, and trinexapac-ethyl + flurpimidol were applied at 0.50, 0.18, 0.37, and 0.09 + 0.22 lb/acre, respectively, on 15 July 2010 and 2 Aug. 2012. In the tank mixing trial, dicamba (0.50 lb/acre), urea (15 lb/acre N), and ammonium sulfate [AMS (15 lb/acre N)] were applied alone or tank mixed with glyphosate at 0 to 0.52 lb/acre. Tank mixing urea with glyphosate had minimal effect on PRG color, while adding AMS consistently improved color at the highest glyphosate rate of 0.52 lb/acre. Twenty days following a glyphosate application, only rates >0.40 lb/acre resulted in significant growth regulation compared with untreated plots. This study indicates that tank mixing glyphosate with another herbicide, a PGR, and various N sources appear safe to the glyphosate-tolerant PRG cultivar. Also, the growth regulating effects of glyphosate applications would serve as an additional benefit to annual bluegrass (Poa annua L.) control reported in previous trials.

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Paclobutrazol Soaked Marigold, Geranium, and Tomato Seeds Produce Short Seedlings

HortScience ◽

10.21273/hortsci.36.4.721 ◽

2001 ◽

Vol 36 (4) ◽

pp. 721-723 ◽

Cited By ~ 7

Author(s):

C.C. Pasian ◽

M.A. Bennett

Keyword(s):

Plant Growth ◽

Plant Growth Regulator ◽

Growth Regulation ◽

Seedling Survival ◽

Seedling Height ◽

Tagetes Patula ◽

Vegetable Crop ◽

Low Light ◽

Bedding Plants ◽

Tomato Seeds

Bedding plants and many vegetable crop seeds are often sown in plug trays. Some crops, like marigold (Tagetes sp. L.), tend to stretch early after germination, especially if grown in low light environments. By the time growers apply plant growth regulators (PGRs), stretching of the hypocotyl has already occurred and seedling applications are ineffective. Seedling height may be controlled by applying the plant growth regulator directly to the seed. Seeds of `Bonanza Gold' marigold (Tagetes patula L.), `Cherry Orbit' geranium (Pelargonium {XtimesX}hortorum L.H. Bailey), and `Sun 6108' tomato (Lycopersicon esculentum Mill.) were soaked for 6, 16, or 24 hours in paclobutrazol solutions of 0, 500, or 1000 mg·L-1. After the soak treatment, seeds were dried for 24 hours prior to laboratory germination testing or sowing in plug trays. Percentage of emergence and seedling height were measured 16, 26, and 36 days after sowing. Laboratory germination of treated seeds was less than that of the control, which was attributed to the PGR being concentrated around the seed on the blotters. In contrast, seedling survival was unaffected in plugs. The higher concentration of PGR and longer times of soaking increased growth regulation, but also inhibited emergence of geraniums (71% vs. 99%). When seeds were imbibed 6, 16, or 24 hours, growth restriction was 31%, 31%, and 40%, respectively, for tomato, 61%, 37%, and 76%, respectively, for geranium and 30%, 38%, and 41%, respectively, for marigold. These results indicate that PGR application to geranium, marigold, and tomato seeds may be feasible using a 6- or 16-hour soak in 500 mg·L-1 paclobutrazol. Chemical name used: (±)-(R*,R*)-ß-[(4-chlorophenyl)methyl]-{XsalphaX}-(1,1-dimethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

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Effects of Paclobutrazol on Royal Palm (Roystonea regia) Trunk and Height Growth

Arboriculture & Urban Forestry ◽

10.48044/jauf.2010.029 ◽

2010 ◽

Vol 36 (5) ◽

pp. 221-223

Author(s):

A.D. Ali ◽

Shawn Bernick

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Cell Elongation ◽

Plant Growth Regulator ◽

Height Growth ◽

Herbaceous Plants ◽

Single Application ◽

Date Palms ◽

Vertical Growth

Paclobturazol is a plant growth regulator which reduces cell elongation and growth. It is commonly used in reducing the growth of herbaceous plants and woody dicots. It has also shown activity against young palms, such as oil and date palms. The effects of basal drench treatments applied annually or as a single application on mature Royal palms (Roystonea regia) were studied over a three-year period. No significant effects were noted on lateral trunk growth. Paclobutrazol treatments resulted in slower vertical growth than in palms not receiving a treatment. However, even at 36 MAT, the average reduction in vertical growth (approx. 50 cm) was still not horticulturally significant relative to the overall palm height of approximately 7 m. Royal palms may attain heights up to 24 m when mature. It is recommended that they not be planted within 7 m of utility lines especially considering regulating their vertical growth is not a practical option.

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Mowing Operations Influence Creeping Bentgrass Putting Green Ball Roll following Plant Growth Regulator Applications

HortScience ◽

10.21273/hortsci.40.2.471 ◽

2005 ◽

Vol 40 (2) ◽

pp. 471-474 ◽

Cited By ~ 6

Author(s):

Patrick E. McCullough ◽

Haibo Liu ◽

Lambert B. McCarty

Keyword(s):

Plant Growth ◽

Plant Growth Regulator ◽

Acid Ethyl Ester ◽

Creeping Bentgrass ◽

Clemson University ◽

The Third ◽

Equal Ball ◽

Green Ball ◽

Putting Green ◽

Cyclohexane Carboxylic Acid

Plant growth regulators (PGRs) are commonly used to enhance putting green quality and ball roll distances but their effects with various mowing operations have not been reported. Three experiments were conducted and repeated at Clemson University, Clemson, SC, on an `L-93' creeping bentgrass putting green to evaluate the effects of mowing operations and PGRs on diurnal ball roll distances. The PGRs tested included ethephon at (a.i.) 3.8 kg·ha-1, flurprimidol at (a.i.) 0.28 kg·ha-1, paclobutrazol at (a.i.) 0.28 kg·ha-1, and trinexapac-ethyl at (a.i.) 0.05 kg·ha-1. Mowing operations tested included rolling vs. mowing, morning mowing vs. morning plus afternoon mowing, and single vs. double morning mowing, all with and without PGRs. PGR by mowing operation interactions did not occur in any experiments. Ball roll distances decreased from 12:00 hr to evening observations in all experiments. In Experiment 1, rolling the green without mowing reduced ball roll distance 4% (5 cm) compared to mowing. Turf rolled without mowing in the morning and treated with flurprimidol, paclobutrazol, and trinexapac-ethyl produced similar ball roll at 12:00, 15:00, and 18:00 hr to mowed untreated turf. In Experiment 2, all plots were mowed at 08:00 hr and half of each plot was remowed at 12:30 hr. The second mowing at 12:30 hr enhanced ball roll distances 6% (8 cm) over the day. Turf mowed only at 08:00 and treated with paclobutrazol and trinexapac-ethyl had greater or equal ball roll distances at 12:30, 15:30, and 18:30 hr to untreated turf that had a second mowing at 12:30 hr. Turf receiving ethephon and 08:00 hr mowing had 4% to 12% (4 to 17 cm) shorter ball roll distances throughout the day compared to untreated turf mowed at 8:00 and 08:00+12:30 hr, respectively. In the third experiment, mowing twice in the morning increased ball roll 3% (4 cm) compared to mowing once. Trinexapac-ethyl and paclobutrazol treated turf mowed once in the morning had greater or equal ball roll distances throughout the day to untreated turf mowed twice in the morning. Overall, PGR use may provide putting green ball roll distances similar to or greater than untreated turf despite additional mowing; however, ethephon reduced ball roll distances regardless of mowing operations. Chemical names used: [4-(cyclopropyl-[α]-hydroxymethylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester] (trinexapac-ethyl); {α-(1-methylethyl)-α-[4-(trifluoro-methoxy) phenyl] 5-pyrimidine-methanol} (flurprimidol); (+/-)-(R*,R*)-β-[(4-chlorophenyl) methyl]-α-(1, 1-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol); [(2-chloroethyl)phosphonic acid] (ethephon).

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Dark-stored Flurprimidol Solutions Maintain Efficacy Over Many Weeks

HortScience ◽

10.21273/hortsci.48.1.77 ◽

2013 ◽

Vol 48 (1) ◽

pp. 77-81 ◽

Cited By ~ 1

Author(s):

William B. Miller

Keyword(s):

Plant Growth ◽

Time Scales ◽

Growth Regulator ◽

Active Ingredient ◽

Plant Growth Regulator ◽

Growth Regulation ◽

Growth Reduction ◽

Height Control ◽

Plant Plant

For a number of geophytic crops, pre-plant plant growth regulator (PGR) dips or soaks are an effective method of height control. Previous research has shown that a given PGR solution may be used to dip numerous bulbs without losing efficacy. What has been unknown is whether PGR solutions maintain efficacy over multiple-week (seasonal) time scales, especially if they have previously been used to treat bulbs. To address this question, 30 mg·L−1 flurprimidol solutions were prepared 3 weeks apart and used to dip narcissus and hyacinth bulbs and then held for 4 weeks at 17 °C in darkness. These solutions (now 7 and 4 weeks old) and a freshly prepared solution were used to dip bulbs of eight hyacinth and five narcissus cultivars. After appropriate cooling, bulbs were forced in a greenhouse. Results indicate no difference in growth reduction among the 0-, 4-, or 7-week-old solutions demonstrating no loss of PGR activity over a 7-week period. In two other experiments, 2.5, 5, and 10 mg·L−1 flurprimidol solutions were exposed to 0 to 8 days of full sun (late June) and then used to dip Lilium ‘Tresor’ bulbs for 1 minute. Growth of the plants indicated loss of growth regulation activity (taller plants) as the duration of exposure to sunlight increased, suggesting substantial photolysis of the active ingredient. Together, the results suggest that flurprimidol solutions can be held in darkness at 17 °C and used for at least 7 weeks without loss of efficacy.

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Effects of Various Plant Growth Regulators on the Traffic Tolerance of ‘Riviera’ Bermudagrass (Cynodon dactylon L.)

HortScience ◽

10.21273/hortsci.45.6.966 ◽

2010 ◽

Vol 45 (6) ◽

pp. 966-970 ◽

Cited By ~ 8

Author(s):

James T. Brosnan ◽

Adam W. Thoms ◽

Gregory K. Breeden ◽

John C. Sorochan

Keyword(s):

Image Analysis ◽

Plant Growth ◽

Plant Growth Regulator ◽

Digital Image Analysis ◽

Cynodon Dactylon ◽

Acid Ethyl Ester ◽

Color Quality ◽

Athletic Field ◽

Traffic Tolerance ◽

Cyclohexane Carboxylic Acid

Data describing effects of plant growth regulator (PGR) applications on bermudagrass (Cynodon spp.) traffic tolerance are limited. A 2-year study was conducted evaluating effects of several PGRs on ‘Riviera’ bermudagrass (Cynodon dactylon L.) traffic tolerance. Treatments included 1) ethephon at 3.8 kg·ha−1; 2) trinexapac-ethyl (TE) at 0.096 kg·ha−1; 3) paclobutrazol at 0.28 kg·ha−1; 4) flurprimidol at 0.0014 kg·ha−1; 5) flurprimidol + TE at 0.0014 kg·ha−1 + 0.096 kg·ha−1, respectively; 6) ethephon + TE at 3.8 kg·ha−1 + 0.096 kg·ha−1, respectively; and 7) untreated control. All treatments were applied three times on a 21-d interval before trafficking. Plots were subjected to three simulated football games per week with the Cady Traffic Simulator. Traffic began 2 weeks after the last sequential application of each PGR. Turfgrass color, quality, and cover were quantified weekly using digital image analysis. Turfgrass cover measurements were used to assess traffic tolerance. Improvements in turfgrass color, quality, and cover were observed with applications of TE, ethephon + TE, and flurprimidol + TE. Turfgrass color, quality, and cover were enhanced for ethephon + TE and flurprimidol +TE compared with applications of ethephon and flurprimidol alone. Considering that no differences in turfgrass color, quality, or cover were detected among TE, ethephon + TE, and flurprimidol + TE at any time in the study, the responses observed suggest that TE may have a greater impact than other PGRs on ‘Riviera’ bermudagrass athletic field turf when applied before traffic stress. Chemical names used: rthephon (2-chloroethyl)phosphonic acid; glurprimidol {α-(1-methylethyl)-α-[4-(trifluoro-methoxy) phenyl] 5-pyrimidine-methanol}; paclobutrazol, (+/−)-(R*,R*)-β-[(4-chlorophenyl) methyl]-α-(1–1-dimethyl)-1H-1,2,4,-triazole-1-ethanol; trinexapac-ethyl [4-(cyclopropyl-[α]-hydroxymethylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester].

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