scholarly journals Efficacy of Plant Growth Regulators on the Growth of Vigorous Osteospermum Cultivars

2003 ◽  
Vol 13 (1) ◽  
pp. 132-135 ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Growth Substrate ◽  
Height Control ◽  
Foliar Sprays ◽  
Peduncle Length

Vigorous osteospermum (Osteospermum ecklonis) cultivars Congo and Wildside received foliar sprays of daminozide or daminozide + chlormequat (Expt. 1). Both cultivars responded similarly to the plant growth regulator (PGR) treatments. Only a limited amount of plant height control occurred using 5,000 mg·L-1 (ppm) daminozide + 1,500 mg·L-1 chlormequat or 5,000 mg·L-1 daminozide + 3,000 mg·L-1 chlormequat. Flowering was delayed, phytotoxicity was observed, while peduncle length increased, suggesting that higher concentrations of daminozide or chlormequat may or not be effective at any concentration and may result in increased phytotoxicity. In Expt. 2, `Lusaka' received foliar sprays or substrate drenches of paclobutrazol or uniconazole. Foliar sprays ≤80 mg·L-1 paclobutrazol or ≤24 mg·L-1 uniconazole were ineffective in controlling plant growth. Substrate drenches of paclobutrazol (a.i.) at 8 to 16 mg/pot (28,350 mg = 1.0 oz) produced compact plants, but at a cost of $0.23 and $0.46/pot, respectively, would not be economically feasible for wholesale producers to use. Uniconazole drenches were effective in producing compact `Lusaka' osteospermum plants. Uniconazole drench concentrations of 0.125 to 0.25 mg/pot were recommended for retail growers, while wholesale growers that desire more compact plants should apply a 0.25 to 0.5 mg/pot drench. Applying uniconazole would cost $0.06 for a 0.25 mg drench or $0.12 for a 0.5 mg drench.

scholarly journals Comparison of Flurprimidol to Ancymidol, Paclobutrazol, and Uniconazole for Tulip Height Control

2005 ◽  
Vol 15 (2) ◽  
pp. 370-373 ◽  
Author(s):  
Brian A. Krug ◽  
Brian E. Whipker ◽  
Ingram McCall ◽  
John M. Dole
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Untreated Control ◽  
Cost Effective ◽  
Height Control ◽  
Foliar Sprays ◽  
Cost Effective Method ◽  
The Cost

Preplant bulb soaks of ancymidol, flurprimidol, paclobutrazol, and uniconazole; foliar sprays of flurprimidol; and substrate drenches of flurprimidol, paclobutrazol, and uniconazole were compared for height control of `Prominence' tulips (Tulipa sp.). Height control was evaluated at anthesis in the greenhouse and 10 days later under postharvest conditions. Substrate drenches of ancymidol, flurprimidol, and paclobutrazol resulted in adequate control using concentrations of 0.5, 0.5, and 1 mg/pot a.i. (28,350 mg = 1 oz), respectively. At these concentrations, ancymidol drenches cost $0.06/pot and paclobutrazol drenches $0.03/pot. Since flurprimidol is not yet available and no price is available, growers will need to assess the cost compared to ancymidol and paclobutrazol. Flurprimidol foliar sprays at <80 mg·L–1 (ppm) were ineffective in controlling height during greenhouse forcing, but during postharvest evaluation 80 mg·L–1 resulted in 14% shorter plants than the untreated control. Preplant bulb soaks of flurprimidol, paclobutrazol, and uniconazole at concentrations of 25, 50, and 10 mg·L–1, respectively, effectively controlled plant height. Preplant plant growth regulator soaks are a cost-effective method of controlling plant height of tulips because of the limited amount of chemical required to treat a large quantity of bulbs.

scholarly journals Plant growth regulators promote growth and yield of summer tomato (lycopersicone sculentum Mill.)

2015 ◽  
Vol 26 (1) ◽  
pp. 32-37 ◽  
Author(s):  
M Rahman ◽  
MA Nahar ◽  
MS Sahariar ◽  
MR Karim
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Fruit Weight ◽  
Fruit Yield ◽  
Growth And Yield ◽  
The Impact

An experiment was conducted at the Horticulture Farm of Bangladesh Agricultural University, Mymensingh to test the impact of plant growth regulators on growth and yield of summer tomato. The experiment consisted of two tomato varieties viz. BARI Hybrid Tomato-4 and BARI Hybrid Tomato-8 and four types of plant growth regulator (PGR)viz.,(i) control (without PGR), (ii) 4-CPA (4-chlorophenoxy acetic acid), GA3 (gibberellic acid) and 4-CPA +GA3. The two-factor experiment was laid out in randomized complete block design with three replications. The results of the experiment revealed that significant variations were observed for most of the characters studied. At 75 DAT, the tallest plant (79.35 cm), number of flowers and fruits (38.11 and 19.04, respectively) plant-1, individual weight (58.44 g) and fruit yield (22.75 t ha-1) were found in BARI Hybrid Tomato-8.At 75 DAT the maximum plant height (87.90 cm), number of flowers and fruits (49.04 and 21.9, respectively) plant-1, individual fruit weight (61.16 g), and fruit yield (27.28 tha-1) were found when 4-CPA + GA3 applied together, whereas the minimum for these characters were recorded from control plants. In case of combined effect of variety and plant growth regulator, the maximum plant height (87.90 cm), number of flowers and fruits (49.04 and 21.91, respectively) plant-1, individual fruit weight (61.16 g) and fruit yield (27.28 t ha-1) were observed in BARI Hybrid Tomato-8 when treated with 4-CPA + GA3together, and the minimum for all these parameters were found in control plants. The results of the present study suggest thatboth 4-CAP and GA3together can be practiced for increasing summer tomato production for both the varieties.Progressive Agriculture 26:32-37, 2015

scholarly journals Ornamental Cabbage and Kale Growth Responses to Daminozide, Paclobutrazol, and Uniconazole

2001 ◽  
Vol 11 (2) ◽  
pp. 226-230 ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Brassica Oleracea ◽  
Plant Height ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Foliar Spray ◽  
Growth Responses ◽  
Height Control ◽  
Foliar Sprays ◽  
Industry Standard

Ornamental cabbage and kale (Brassica oleracea var. acephala) plants of cultivars Osaka White and Nagoya Red were treated with paclobutrazol and uniconazole as foliar sprays or substrate drenches. These treatments were compared to the industry standard of daminozide foliar sprays. Applying drenches of paclobutrazol (a.i.) at 4 mg/pot or uniconazole (a.i.) at 1 mg/pot (28,350 mg = 1.0 oz) resulted in 6% or 17%, respectively, shorter `Osaka White' plants while a 2 mg/pot paclobutrazol drench or a uniconazole drench at 0.25 mg/pot resulted in 25% shorter `Nagoya Red' plants. Although effective, the expense of substrate drenches for both plant growth regulators (PGRs) would not be economically feasible for growers to use. Paclobutrazol foliar sprays at concentrations of up to 80 mg·L-1 (ppm) were ineffective in controlling plant height and diameter of either `Osaka White' or `Nagoya Red'. A uniconazole foliar spray of 16 mg·L-1 resulted in 17% shorter `Nagoya Red' plants and 6% shorter `Osaka White' plants. A daminozide foliar spray of 2500 mg·L-1, sprayed twice, resulted in 21% shorter plants for both cultivars. Spraying daminozide would provide optimal height control for the retail grower. Although spraying daminozide twice controlled plant height and costs half the amount of an uniconazole spray at 16 mg·L-1, plant diameter was not affected with daminozide, therefore a wholesale grower who would desire a smaller diameter plant should use a uniconazole spray of 16 mg·L-1.

scholarly journals Plant Growth Regulator Impacts on Vegetative Cutting Production of Moroccan Pincushion (Pterocephalus depressus) Plants

2021 ◽  
Vol 39 (2) ◽  
pp. 62-67
Author(s):  
Sean J. Markovic ◽  
James E. Klett
Keyword(s):  
Plant Growth ◽  
Gibberellic Acid ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Growth Index ◽  
Dry Weight ◽  
Stock Plant ◽  
Cutting Production

Abstract Moroccan pincushion (Pterocephalus depressus) is a drought-tolerant perennial that is being used in landscapes throughout arid areas of the western United States. This paper describes two experiments researching vegetative cutting production from stock plants. Moroccan pincushion stock plants received foliar applications of gibberellic acid (GA3), benzyladenine, ethephon, or auxin [indole-3-butyric acid (IBA)] plant growth regulators (PGR). Plant growth regulators were applied singularly and in combination with GA3 to determine efficacy on stock plant growth. A propagation study was conducted simultaneously to determine effects of these different PGR treatments applied to stock plants on the rooting of moroccan pincushion cuttings. The stock plant study showed GA3 + benzyladenine application increased cutting production over other PGR treatments. Fresh weight of moroccan pincushion cuttings did not differ among treatments. While cuttings did not differ in dry weight in experiment 1, statistical differences were observed in experiment 2. However, these differences in dry weight did not affect the quality of the cuttings. Cuttings from stock plants treated with GA3 + IBA treatment had the highest numerical growth index [(height + width + width)/3]. Cuttings from stock plants treated with GA3 alone or in combination with another PGR were all greater in average growth index and statistically differed from those without GA3 being applied. PGR treatments did not affect rooting percentages of the cuttings with nontreated stock plant cuttings successfully rooting at an average rate of 95%. However, GA3 + IBA was the only treatment where cuttings had 100% rooting for both experiments, indicating potential rooting benefits. Index words: Plant growth regulator, propagation, Pterocephalus depressus, vegetative cuttings. Species used in this study: Moroccan pincushion [Pterocephalus depressus Archibald]. Chemicals used in this study: gibberellic acid (GA3), benzyladenine, ethephon, indole-3-butyric acid (IBA).

scholarly journals Controlling Height and Seedling Emergence of French Marigold and Celosia Plugs with Plant Growth Regulators

2006 ◽  
Vol 24 (3) ◽  
pp. 165-168
Author(s):  
Stanislav V. Magnitskiy ◽  
Claudio C. Pasian ◽  
Mark A. Bennett ◽  
James D. Metzger
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Seedling Emergence ◽  
Foliar Spray ◽  
Seedling Height ◽  
Foliar Sprays ◽  
Spray Applications

Abstract Soaking French marigold seeds in growth regulator solutions produced larger reductions in seedling height than foliar sprays. Seeds soaked in 1 to 5 ppm uniconazole solutions for 0.15, 5, or 45 min resulted in plants that were up to 23% shorter than controls at 30 DAS, whereas foliar applications of 10 to 20 ppm uniconazole solutions resulted in plants 18% shorter than controls at 14 DAS. French marigold seedlings from seeds soaked in 60 pm ancymidol for 5 or 45 min were 5 or 6%, respectively, shorter than controls. Foliar spray applications of 25 or 100 ppm ancymidol to French marigold seedlings resulted in plants 8% shorter than controls. Chlormequat solutions applied either as a seed soak (1000–5000 ppm) or foliar spray (500–3000 ppm) did not reduce French marigold seedling height. Emergence of French marigold seedlings from seeds soaked in uniconazole, ancymidol, or chlormequat solutions was not different from that of control seeds. No effect on seedling height or emergence was found when soaking celosia seeds in uniconazole, ancymidol, or chlormequat solutions. Spraying celosia seedlings with uniconazole, ancymidol, or chlormequat solutions did not reduce seedling height.

scholarly journals Effects of Pinching, Number of Cuttings per Pot, and Plant Growth Regulators on Height Control of Purple Firespike

2015 ◽  
Vol 25 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Plant Height ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Stem Elongation ◽  
Dry Weight ◽  
Maximum Height ◽  
Height Control ◽  
Leaf Dry Weight

Purple firespike (Odontonema callistachyum), native to Central America, has potential for use as a new flowering potted plant. The effects of number of pinches (zero, one, or two) and number of cuttings (one, two, or three) per 6-inch pot were evaluated on the control of plant height. Plant height was suppressed as the pinch number increased. The greatest reduction was recorded with one cutting per pot and two pinches. The maximum number of branches per pot was recorded with two pinches and three cuttings per pot. In a second experiment, plant growth regulators (PGR) were also tested for efficacy of height control; 2 weeks after pinching, foliar sprays of paclobutrazol, flurprimidol, daminozide, chlormequat, and a tank-mix of daminozide + chlormequat or media drenches of paclobutrazol, uniconazole, or flurprimidol were applied. Plant height, leaf area, and leaf dry weight were recorded at 3, 6, and 9 weeks after PGR application. Maximum height control was obtained with uniconazole drench at 8 ppm, resulting in plants 22 cm tall, 61% shorter than the untreated control (56 cm); however, it resulted in severe leaf distortion. Plant height was 56% and 46% shorter than the control using drenches of paclobutrazol at 30 ppm and flurprimidol at 15 ppm, respectively. Daminozide spray at 2000 ppm and tank-mix of daminozide + chlormequat at 4500/1500 ppm suppressed stem elongation by 20.3% and 19%, respectively. Plants treated with paclobutrazol drench at 30 ppm reduced leaf area and leaf dry weight compared with other PGRs. Chlormequat spray at tested concentrations was ineffective for controlling firespike plant growth. The most attractive potted plants were produced using a drench application of paclobutrazol at 10 or 15 ppm.

scholarly journals FLOWER PETAL PIGMENTATION AFFECTED BY THE EXPERIMENTAL PLANT GROWTH REGULATOR A-1699 DF

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 886d-886
Author(s):  
Todd J. Cavins
Keyword(s):  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Active Ingredient ◽  
Plant Growth Regulator ◽  
Experimental Plant ◽  
Flower Petal ◽  
Biochemical Processes ◽  
Height Control ◽  
Anthocyanin Production

Anti-gibberellin plant growth regulators (PGRs) not only affect cell elongation, but other biochemical processes. The experimental PGR A-1699 DF was evaluated for efficacy of height and width control as well as effect on flower petal pigmentation. While the active ingredient in A-1699 DF has proven effective for height control on several crops, that was not observed on Impatiens `Accent Cranberry' in this study. However, A-1699 DF did affect flower petal pigmentation. A-1699 DF likely inhibited anthocyanin production that resulted in light pink versus cranberry flower petals observed on the control, Paczol, and B-Nine/Cycocel PGR applications.

scholarly journals Paclobutrazol, Uniconazole, or Flurprimidol Applied at Various Concentrations as a Substrate Drench or Through Subirrigation Have Little Effect on Bee Balm Growth

2014 ◽  
Vol 24 (3) ◽  
pp. 313-317
Author(s):  
Rachael E. Pepin ◽  
Janet C. Cole
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Plant Size ◽  
Plant Responses ◽  
Production Environments ◽  
Monarda Didyma

Summer and fall studies investigated the control of growth of bee balm (Monarda didyma ‘Marshall’s Delight’) by paclobutrazol, uniconazole, or flurprimidol applied to the substrate as a surface drench or through subirrigation. Flurprimidol and uniconazole were applied at 0, 0.5, 1.0, 1.5, or 2.0 ppm (0, 0.09, 0.18, 0.27, or 2.0 mg/pot), while paclobutrazol was applied at 0, 2, 4, 6, or 8 ppm (0, 0.6, 1.2, 1.8, or 2.4 mg/pot). Substrate drench applications were more effective than applications through subirrigation at reducing plant growth. Few trends in application concentrations within plant growth regulator occurred for the plant parameters measured. Based on inconsistent plant responses between the two studies and few differences among application concentrations, we do not recommend any of these plant growth regulators for controlling plant size of bee balm during production without further testing in production environments specific to bee balm.

scholarly journals Vegetatively Propagated Geraniums Respond Similarly to Drench Applications of Paclobutrazol or Uniconazole

2000 ◽  
Vol 10 (1) ◽  
pp. 151-153 ◽  
Author(s):  
Brian E. Whipker ◽  
Shravan K. Dasoju ◽  
Michael R. Evans
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Canopy Height ◽  
Height Control ◽  
Total Height ◽  
Potted Plants ◽  
Total Plant ◽  
Leaf Canopy

Drench applications of paclobutrazol or uniconazole were applied at doses of 0, 0.0025, 0.005, 0.01, 0.02, or 0.04 mg a.i./pot (28,350 mg = 1.0 oz) to vegetatively propagated `Aurora', `Medallion Dark Red', and `Pink Satisfaction' geranium (Pelargonium ×hortorum L.H. Bailey). Geranium total plant height, leaf canopy height, and plant diameter responded similarly to drench applications of either paclobutrazol or uniconazole. There was a significant quadratic relationship between plant growth regulator (PGR) dose and total plant height and leaf canopy height for `Aurora' and `Medallion Dark Red', with total plant height and leaf canopy height being shorter as paclobutrazol or uniconazole doses increased up to 0.02 mg. However, doses of ≥0.02 mg had little additional effect on total plant height and leaf canopy height. Most of the total height control achieved by the use of PGRs was primarily due to a reduction of leaf canopy height, rather than inflorescence height. Doses of 0.005 to 0.01 mg of either PGR produced marketable sized potted plants of `Medallion Dark Red' and `Pink Satisfaction'. `Aurora', which was the most vigorous cultivar, required doses of 0.01 or 0.02 mg of either paclobutrazol or uniconazole to produce marketable sized potted plants.

scholarly journals Plant Growth Regulators

EDIS ◽  
2009 ◽  
Vol 2009 (4) ◽  
Author(s):  
Frederick M. Fishel
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Previous Version ◽  
Fact Sheet ◽  
Patterns Of Use

Revised! PI-102, a 5-page fact sheet by Frederick M. Fishel, defines the term, “plant growth regulator,” addresses patterns of use for plant growth regulators, and provides a listing of plant growth regulators registered for use in Florida. Published by the UF Department of Agronomy, April 2009. Revised January 2015 and February 2018. Retired from active collection, February 11, 2021.   Previous version: Fishel, Frederick. 2006. “Plant Growth Regulators”. EDIS 2006 (6). https://doi.org/10.32473/edis-pi139-2006.

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