scholarly journals Plant Growth Retardants Affect Growth and Flowering of Achillea × ‘Coronation Gold’

2008 ◽  
Vol 26 (1) ◽  
pp. 24-28 ◽  
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Growth Index ◽  
Plant Size ◽  
Growth Retardant ◽  
Growth Retardants ◽  
Shoot Height ◽  
Stage Of Development ◽  
Quality Ratings ◽  
Plant Growth Retardants

Abstract An experiment was conducted to determine the effects of several widely used plant growth retardants on plant size and flowering of Achillea × ‘Coronation Gold’. Plants in 10 cm (4 in) pots were grown in a greenhouse and treated with B-Nine at 0, 2550, 5100, or 7650 ppm; Cycocel at 0, 767, 1534, or 2301 ppm; B-Nine/Cycocel at 0, 1275/1534, 2550/1534, or 3825/1534 ppm; Sumagic at 0, 11, 22, 33, 44, or 55 ppm; Bonzi at 0, 32, 64, 96, 128, or 160 ppm; or Cutless at 0, 40, 80, or 120 ppm as a spray 1 week after vernalization. B-Nine, Cycocel, B-Nine/Cycocel, Sumagic, Bonzi, and Cutless reduced shoot height and growth index by 36 and 26%, 39 and 27%, 61 and 41%, 75 and 52%, 52 and 36%, and 75 and 51%, respectively, with the highest rate of each. B-Nine, Cycocel, B-Nine/Cycocel, and Sumagic, but not Bonzi or Cutless, increased the number of days to open inflorescence by 3-5 days with increasing rate. Sumagic, Bonzi, and Cutless reduced inflorescence diameter by up to 15, 18, and 14%, respectively but not B-Nine, Cycocel, or B-Nine/Cycocel. The highest quality ratings of 2.8 to 3.0 were found with B-Nine/Cycocel at 3825/1534 ppm, Sumagic at 22 and 33 ppm, and Bonzi at 64 ppm. Differences between the results in this study and earlier studies implicate the possible impact of differences in experimental environments, container size, or stage of development when the plant growth retardant treatments were applied.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Coreopsis verticillata ‘Moonbeam’

2007 ◽  
Vol 25 (4) ◽  
pp. 229-233
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Maleic Hydrazide ◽  
Growth Index ◽  
Height Growth ◽  
Growth Retardant ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Quality Ratings ◽  
Quality Rating

Abstract This investigation was conducted to determine the plant growth retardant type, application method, and rate required to produce a marketable greenhouse pot plant of Coreopsis verticillata L. ‘Moonbeam’. Pruned plants in 10 cm (4 in) pots received growth retardant treatments in two experiments consisting of one application of ancymidol or paclobutrazol medium drenches at 0, 2, 4, or 6 ppm; daminozide spray at 0, 2550, 5100, or 7650 ppm; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 ppm; flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 ppm; or maleic hydrazide at 0, 360, 720, 1080, 1440, or 1800 ppm in the first experiment and sprays of daminozide at 0, 2550, 5100, or 7650 ppm; paclobutrazol at 0, 60, or 120 ppm; daminozide/paclobutrazol combinations at 0, 2550/16, 2550/32, 2550/48, or 2550/64 ppm, chloromequat at 0, 767, 1534, or 2301 ppm; or daminozide/chloromequat combinations at 0, 1275/1534, 2550/1534, 3825/1534, or 5100/1534 ppm in the second experiment. In the first experiment, there was a linear decrease in shoot height, growth index, and lateral shoot length with increasing rates of ancymidol and paclobutrazol drenches and flurprimidol sprays while daminozide decreased growth quadratically. There was a linear increase in shoot height and lateral shoot length with increasing rates of maleic hydrazide but no effect on growth index. Only daminozide and maleic hydrazide increased the number of days from treatment to flower with increasing rates. Quality ratings increased with increasing rates of ancymidol, daminozide, and flurprimidol with the highest ratings found at the two highest rates of daminozide and flurprimidol. Paclobutrazol spray did not affect the parameters measured. In the second experiment, chloromequat spray did not affect the parameters measured but when combined with increasing rates of daminozide, linearly decreased shoot height, growth index, and lateral shoot length while increasing the number of days to flower. Daminozide alone resulted in a quadratic change in growth index and lateral shoot length while linearly increasing the number of days to flower but with no effect on quality rating. The higher rates of paclobutrazol than were used in the first experiment decreased shoot height and lateral shoot length with no effect on growth index, the number of days to flower, or quality rating. Overall, the best quality ratings and the most compact plants resulted from spray applications of daminozide at 5100 ppm or 7650 ppm and flurprimidol at 150 ppm or 200 ppm, however flurprimidol is not currently registered for application to greenhouse crops but a newer product, Topflor, has the same active ingredient and greenhouse crop labeling.

scholarly journals Plant Growth Retardants Reduce Peduncle Length of Achillea × `Coronation Gold'

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 602f-603
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Plant Growth ◽  
Growth Index ◽  
Market Quality ◽  
Growth Retardants ◽  
Foliar Sprays ◽  
Quality Ratings ◽  
Flower Diameter ◽  
Plant Growth Retardants ◽  
Peduncle Length

Vegetative offsets of Achillea x `Coronation Gold' were rooted under mist for 3 weeks and potted into 10-cm pots in a greenhouse. Plants were grown under short photoperiods for 6 weeks before being vernalized for 6 weeks at 6 °C. Plants then were provided long photoperiods from night-break lighting. Foliar sprays of daminozide at 0, 2550, 5100, or 7650 mg·L-1, chlormequat at 0, 767, 1534, or 3201 mg·L-1, daminozide + chlormequat at 0, 1275 +, 2550 + or 3825+1534 mg·L-1, flurprimidol at 0, 40, 80, or 120 mg·L-1, paclobutrazol at 0, 32, 64, 96, 128, or 160 mg·L-1 or uniconizole at 0, 11, 22, 33, 44, or 55 mg·L-1 were applied as a spray 1 week after vernalization. Highest market quality ratings were achieved with paclobutrazol at 96 or 128, uniconizole at 22 or 33, daminozide + chlormequat 3825 + 1534, chlormequat at 2301 or flurprimidol at 40 mg·L-1. Peduncle length and growth index decreased linearly for daminozide, chlormequat, and daminozide + chlormequat, and decreased quadratically for flurprimidol, paclobutrazol, and uniconizole with increasing rate. Time to flower increased most in treatments receiving high rates of daminozide. Flower diameter was reduced by the highest rates of flurprimidol and paclobutrazol.

scholarly journals Plant Growth Retardant Application to Achillea x ‘Coronation Gold’ and Gaura lindheimeri ‘Corrie's Gold’

2000 ◽  
Vol 18 (3) ◽  
pp. 149-153
Author(s):  
Stephanie E. Burnett ◽  
Gary J. Keever ◽  
Charles H. Gilliam ◽  
J. Raymond Kessler ◽  
Charles Hesselein
Keyword(s):  
Plant Growth ◽  
Untreated Control ◽  
Growth Suppression ◽  
Effective Concentration ◽  
Growth Retardant ◽  
Growth Retardants ◽  
Herbaceous Perennials ◽  
Quality Ratings ◽  
Plant Growth Retardants ◽  
Delayed Flowering

Abstract In two experiments conducted under nursery conditions in 1998 and 1999, the herbaceous perennials, Achillea x ‘Coronation Gold’ and Gaura lindheimeri ‘Corrie's Gold’ were treated with one of four plant growth retardants (PGRs): B-Nine at 2,500, 5,000, or 7,500 ppm; Bonzi at 33, 66, or 99 ppm; Cutless at 50, 100, or 150 ppm; Pistill at 500 or 1,000 ppm; or left untreated. Only Pistill delayed flowering of achillea while Bonzi and Cutless accelerated flowering of achillea. In 1998, B-Nine provided little growth suppression of achillea; however in 1999, when plants were pruned just prior to treatment and thus less reproductively developed, height at the most effective concentration of 7,500 ppm was reduced 33% compared to untreated plants over the duration of the experiment. At the most effective concentration of 99 ppm, Bonzi retarded growth 15% and 31%, over the duration of the experiment, while Cutless at 150 ppm suppressed growth 21% and 46% in 1998 and 1999, respectively, compared to an untreated control. Plants treated with the most effective concentration of Pistill were 13% and 21% shorter than non-treated plants over the duration of the experiment in 1998 and 1999, respectively. However, in 1998 quality ratings of Pistill-treated plants were lower than for control plants, and the duration of control was shorter than with B-Nine, Bonzi, or Cutless in 1999. Only Cutless provided consistent growth suppression of gaura; plants treated with the most effective concentration of 150 ppm were an average of 19% smaller at 60 days after treatment (DAT) in 1998 and 13% smaller than control plants from 28 to 70 DAT in 1999. B-Nine and Pistill provided more transitory control. In 1999, the most effective concentration of B-Nine suppressed growth 9% from 28 to 56 DAT. Plants treated with the most effective concentration of Pistill of 500 ppm averaged 23% smaller at 14 and 28 DAT than control plants. Application of Pistill delayed flowering 11 to 13 days in 1998.

scholarly journals (94) Efficacy of Application Methods and Concentration of Plant Growth Retardants on Growth of Chrysanthemum (Dendranthem ×grandiflorum `Cheasepeake')

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1046A-1046
Author(s):  
Chun Ho Pak ◽  
Seung Won Kang ◽  
Chiwon W. Lee
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Nutrient Solution ◽  
Growth Retardation ◽  
Growth Retardant ◽  
Plant Production ◽  
Growth Retardants ◽  
Total Plant ◽  
Plant Growth Retardants ◽  
Application Methods

Efficacy of application methods and concentration of plant growth retardants on growth of chrysanthemum (Dendranthema ×grandiflorum cv. Cheasepeake) was tested. B-9 or cycocel (CCC) as a growth retardant was applied as drench or subapplication with nutrient solution. In the case of B-9 drench treatments, as B-9 concentrations increased, numbers of flowers and flower buds increased except in the 1500-ppm treatment. Increasing concentration of CCC also resulted in reduction of flower numbers, total plant height, total leaf area, branch number, and fresh weight. Reduction ratio of total plant height in 2000 ppm showed about 56.9% being compared to that of the 100-ppm drench treatment. B-9 or CCC, combined with nutrient solution, was also supplied from the C-channel subirrigation system. The B-9 subapplication treatment showed no significance among these concentrations, but flower numbers, total plant height, average plant height, and leaf numbers decreased as concentrations of CCC increased. B-9 or CCC with the same concentration was drenched after 2 weeks of the first experiment to compare planting time efficacy. Measured data increased until B-9 increased up to 2500 ppm and severe growth retardation resulted from the 5000-ppm treatment. Through this growth retardant application study, the combination of drenching concentration and period of plant growth regulators (PGRs) may result in effective growth retardation and reduction of application concentrations for pot plant production.

scholarly journals Foliar Application of Plant Growth Retardants to Coreopsis rosea ‘American Dream’

2000 ◽  
Vol 18 (2) ◽  
pp. 59-62
Author(s):  
S.E. Burnett ◽  
G.J. Keever ◽  
J.R. Kessler ◽  
C.H. Gilliam
Keyword(s):  
Plant Growth ◽  
American Dream ◽  
Foliar Application ◽  
Plant Quality ◽  
Growth Retardants ◽  
Quality Ratings ◽  
Control Growth ◽  
Plant Growth Retardants

Abstract In one experiment conducted in 1998 and two in 1999, Coreopsis rosea ‘American Dream’, or pink coreopsis, were treated with four plant growth retardants (PGRs): B-Nine from 2500 to 7,500 ppm, Cutless from 25 to 150 ppm, Sumagic from 10 to 40 ppm, and Bonzi from 25 to 100 ppm. The study was conducted to determine whether PGRs could be used to suppress growth of pink coreopsis without delaying flowering or causing phytotoxicity. Application of B-Nine, Cutless, or Sumagic suppressed plant growth 13–31% at first flower and when plants were marketable (one-third of flowers open) in all experiments and improved plant quality compared to controls. Plants treated with B-Nine, Cutless, or Sumagic had quality ratings 52–67% higher than those of control plants when marketable; treated plants appeared denser and more floriferous. Time to first flower and to a marketable stage were minimally affected by PGR application, and no phytotoxicity was observed. Bonzi did not significantly control growth or affect flowering of pink coreopsis in any of the three experiments.

scholarly journals Effect of Selected Growth Retardants on `Arabe' Grapevines

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 602F-602
Author(s):  
Gonzalo Morales-Salazar ◽  
Jose P. Morales-Payan ◽  
Bielinski M. Santos
Keyword(s):  
Plant Growth ◽  
Dominican Republic ◽  
Active Ingredient ◽  
Vegetative Growth ◽  
Field Experiments ◽  
Growth Retardant ◽  
Regression Equations ◽  
Growth Retardants ◽  
Short Term ◽  
Plant Growth Retardants

The effect of three plant growth retardants, bitertanol, tradimefon, and hexaconazole, on short-term vine regrowth of pruned `Arabe' grape (Vitis vinifera) was studied in field experiments conducted in the Dominican Republic. Individual soil drench treatments of the three retardants were applied to adult pruned `Arabe' grape plants at rates 0, 0.25, 0.50, 0.75 and 1.00 g active ingredient per plant. Three weeks after treatment, bitertanol did not have a significant effect on vegetative growth, whereas triadimefon and hexaconazole caused significant reductions on vine regrowth. The effect of triadimefon as a growth retardant was stronger than that of hexaconazole, as described by regression equations Y = 30.88 - 25.68X for triadimefon, and Y = 32.9 - 15.2X for hexaconazole.

Effects of Plant Growth Retardants and Application Timing after Shearing on Growth and Flowering of Coreopsis verticillata `Moonbeam'

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522a-522
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Index ◽  
Market Quality ◽  
Growth Retardants ◽  
Application Timing ◽  
Quality Rating ◽  
Plant Growth Retardants ◽  
Herbaceous Perennial ◽  
Short Days

Coreopsis verticillata `Moonbeam' is a herbaceous perennial that may grow too tall in small containers under greenhouse conditions for market acceptance, and therefore may benefit from plant growth retardants. Rooted terminal cuttings produced under short days were given a terminal pinch and transplanted to 10 cm pots. Cuttings were sheared to 6 cm above the pot rim 4 weeks later. Growth retardant treatments consisting of ancymidol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; paclobutrazol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; daminozide spray at 0, 2550, 5100, or 7650 mg·L–1; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 mg·L–1; or flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 mg·L–1 were applied 10 days after shearing. Night-breaking lighting using incandescent bulbs was started the same day. The highest rate of ancymidol, paclobutrazol drench, daminozide, and flurprimidol decreased plant height compared to controls by 36, 30, 21, and 36%, respectively. Paclobutrazol sprays were not effective. A market quality rating of four or higher (good, salable) was given to plants treated with daminozide at 5100 or 7650 mg·L–1 or flurprimidol at 150 or 200 mg·L–1. A second experiment was conduced to determine application timing. A daminozide spray at 0, 2550, 5100, or 7650 mg·L–1 was applied 0, 3, 6, 9, 12, or 15 days after shearing. Plant height, growth index and lateral shoot length were least and market quality rating highest when 5100 or 7650 mg·L–1 of daminozide was applied between 6 and 9 days after shearing.

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 Inhibition by Plant Growth Retardants of Cholesterol Biosynthesis in Slices of Rat Liver and Hepatoma

1971 ◽  
Vol 24 (4) ◽  
pp. 1125 ◽  
Author(s):  
L Paleg ◽  
JR Sabine
Keyword(s):  
Plant Growth ◽  
Cholesterol Synthesis ◽  
Cholesterol Biosynthesis ◽  
Normal Liver ◽  
Acid Synthesis ◽  
Growth Retardant ◽  
Growth Retardants ◽  
Host Liver ◽  
Plant Growth Retardants ◽  
Amo 1618

The plant growth retardant Phosfon inhibits cholesterol formation by cell�free preparations of normal liver and the Morris hepatomas 5123C, 7794A, and 9618A. In addition, both Phosfon and Amo 1618 arc active in inhibiting cholesterol synthesis from acetate and mevalonate in slices of host liver and the hepatomas. Fatty acid synthesis from acetate was also reduced in the presence of the retardants.

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