scholarly journals Responses of Nine Containerized Perennials to Sumagic

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 593B-593
Author(s):  
Joyce G. Latimer ◽  
Paul A. Thomas

Nine perennial bedding plants were screened for responsiveness to the plant growth retardant, Sumagic (uniconazole-P). Two weeks after planting, plugs were treated with one foliar spray of Sumagic at 0, 40, 80, 120, or 160 ppm at the label-recommended volume. Plant growth of Gaillardia grandiflora `Goblin' was not reduced by Sumagic. Height of Achillea × `Moonshine' was reduced 8% to 12% at 4 weeks after treatment (WAT), and the reduction persisted through 8 weeks after planting (WAP) to the landscape. Phlox paniculata `Joliet' responded linearly to increasing Sumagic rate with a maximum height reduction of 32% at 160 ppm. Coreopsis grandiflora `Sunray', Rudbeckia fulgida var. Sullivantii `Goldsturm' and Monarda didyma `Blue Stocking' responded significantly to Sumagic with 30% to 60% height reductions at 4 WAT, but no persistent effects at 8 WAP. Height of Veronica alpine `Goodness Grows' was reduced 32% to 68% at 4 WAT, but all Sumagic rates resulted in persistent reductions in plant height at 12 WAP. Plant height of Alcea rosea mix and Echinacea purpurea were excessively reduced (up to 79%) at 4 WAT, but there were no persistent effects on height of Alcea in the landscape. All rates of Sumagic resulted in persistent reductions in height of Echinacea at 8 WAP, but only plants treated with 120 and 160 ppm Sumagic were still significantly shorter than controls at 12 WAP

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438D-438
Author(s):  
Brian E. Whipker ◽  
Shravan Dasoju

Plant growth retardant (PGR) foliar spray treatments (mg•liter–1) of daminozide at 1000 to 16,000; paclobutrazol from 5 to 80; and uniconazole from 2 to 32 were applied to `Pacino' pot sunflowers (Helianthus annuus) to compare their effectiveness at chemical height control. When the first inflorescence opened, the number of days from seeding until flowering, total plant height measured from the pot rim to the top of the inflorescence, inflorescence diameter, and plant diameter were recorded. Total plant height, plant diameter, inflorescence diameter, and days until flowering were significant for the PGR treatment interaction. Marketable-sized plants grown in the 1.2-liter pots were produced with uniconazole concentrations between 16 and 32 mg•liter–1 or with daminozide concentrations between 4000 and 8000 mg•liter–1. Paclobutrazol foliar sprays up to 80 mg•liter–1 had little effect and higher concentrations or medium drench treatments should be considered.


1998 ◽  
Vol 8 (1) ◽  
pp. 86-88 ◽  
Author(s):  
Brian E. Whipker ◽  
Shravan Dasoju

Plant growth retardant (PGR) foliar sprays (in mg·L−1) of daminozide at concentrations from 1,000 to 16,000; paclobutrazol from 5 to 80; and uniconazole from 2 to 32 were applied to `Pacino' potted sunflowers (Helianthus annuus L.) to compare their effectiveness at chemical height control. Plants were grown in 650-mL or 1.2-L pots. When the first inflorescence started to shed pollen, number of days from seeding until anthesis, total plant height measured from the pot rim to the top of the inflorescence, inflorescence diameter, and plant diameter were recorded. There was no significant difference in plant height between `Pacino' plants grown in 650-mL or 1.2-L pots. Total plant height, plant diameter, inflorescence diameter, and days until flowering were significant for the PGR treatment main effect. Marketable-sized plants grown in the 1.2-L pots were produced with uniconazole concentrations from 16 to 32 mg·L−1 or with daminozide concentrations from 4,000 to 8,000 mg·L−1. Paclobutrazol foliar sprays up to 80 mg·L−1 had little effect, and higher foliar spray concentrations or substrate drench treatments may be needed to effectively control height.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ahmadi ◽  
Abbas Samadi ◽  
Ebrahim Sepehr ◽  
Amir Rahimi ◽  
Sergey Shabala

AbstractMedicinal plants represent a valuable commodity due to beneficial effects of their natural products on human health, prompting a need for finding a way to optimize/increase their production. In this study, a novel growing media with various perlite particle size and its mixture with peat moss was tested for hydroponic-based production of Echinacea purpurea medicinal plant under greenhouse conditions. The plant growth parameters such as plant height, total fresh leave weight, fresh root weight, total biomass, total chlorophyll, leaf area, and essential oil compositions were assessed. Perlite particle size in the growing media was varied from very coarse (more than 2 mm) to very fine (less than 0.5 mm), and the ratio between perlite and peat moss varied from 50:50 v/v to 30:70 v/v. In addition, two nitrate (NO3−) to ammonium (NH4+) ratios (90:10 and 70:30) were tested for each growing media. The medium containing very fine-grade perlite and 50:50 v/v perlite to peat moss ratio was found to be most optimal and beneficial for E. purpurea performance, resulting in maximal plant height, fresh and dry weight, leaf surface area, and chlorophyll content. It was also found that an increase in NO3−/NH4+ ratio caused a significant increase in plant growth parameters and increase the plant essential oil content. The major terpene hydrocarbons found in extract of E. purpurea with the best growth parameters were germacrene D (51%), myrcene (15%), α-pinene (12%), β-caryophyllene (11%), and 1-Pentadecene (4.4%), respectively. The percentages of these terpene hydrocarbons were increased by increasing of NO3−/NH4+ ratio. It can be concluded that decreasing the perlite particle size and increasing the NO3−/NH4+ ratio increased the plant growth parameters and essential oil compositions in E. purpurea.


2015 ◽  
Vol 25 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess

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.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1046A-1046
Author(s):  
Chun Ho Pak ◽  
Seung Won Kang ◽  
Chiwon W. Lee

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.


2019 ◽  
pp. 1-6
Author(s):  
Amar Bahadur Pun Magar

Carnation is an important cut flower in Nepal. Several cultivars imported from abroad are being adopted for their commercial production. However, the performance of these cultivars in  the specific agro-climate has not yet determined. Thus, study aimed to evaluate the performance  of common cultivars, including mineral nutrition and IAA hormone on the plant growth and flowering. The study was carried out in Horticulture Research Division, Khumaltar, Nepal during 2012 and 2013. Four cultivars: King Lion, Delson, Eskimo and White Liberty including nitrogen and foliar application of IAA were evaluated for plant growth and floral characteristics. The experiment was held in randomized complete block design (RCBD) with four replications.Based on the results, cultivar King Lion had significantly highest plant height (20.66 cm),  while cultivar Eskimo had the highest flower stem length (53.59 cm) and stem diameter (5.63 cm) followed by Delson (51.66 cm). The lower flower stems lengths of cultivars: White Liberty (42.48 cm) and King Lion (43.87 cm) were at par. The effect of mineral nutrition and hormone on plant height, flower stem length and flower head diameter was non-significant, however, IAA 25 ppm foliar spray was found superior over N 40 g/m2 and IAA 50 ppm applications. Thus, Eskimo is recommended as the excellent cultivar for its bigger flower stem, straightness and attractive flower looking, while cultivars; Delson and White Liberty as promising for higher flower yield. Similarly, soil application of nitrogen @ 40 g/m2 and foliar spray of auxin @ 25 ppm are recommended for higher flower yield.


1991 ◽  
Vol 9 (4) ◽  
pp. 203-206
Author(s):  
Gary J. Keever ◽  
William J. Foster

Abstract Growth and flowering responses of Pelargonium × hortorum L. H. Bailey ‘Ringo Deep Scarlet’, Tagetes erecta L. ‘Inca Orange’, Viola × wittrockiana Gams. ‘Blue Shades’, Impatiens × ‘Zenith’ and Salvia farinacea Benth. ‘Victoria Blue’ to uniconazole applied at the seedling stage were evaluated at the end of production and 5 to 7 weeks after transplanting into the landscape (geranium, impatiens and salvia only). A drought stress evaluation was also conducted. Response to uniconazole varied with species, sampling date and uniconazole concentration. Growth of all species was suppressed when measured 4½ to 8½ weeks after treatment (WAT), and stress tolerance of all species except marigold increased with increasing concentrations of uniconazole. Flowering generally was delayed with uniconazole. Impatiens and geranium treated with 10 ppm or less of uniconazole were similar in height to nontreated plants 5 to 7 weeks after being transplanted; at this time, uniconazole had no effect on plant height or shoot dry weight of salvia. Daminozide applied once as a 5000 ppm foliar spray was not effective in suppressing vegetative growth of any of the tested species.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438C-438
Author(s):  
Shravan K. Dasoju ◽  
Brian E. Whipker

Drench applications of plant growth retardant paclobutrazol were applied at 2, 4, 8, 16, or 32 mg a.i./pot, plus an untreated control to pot sunflowers (Helianthus annuus cv. `Pacino') to determine its effect as a chemical height control. All paclobutrazol concentrations applied significantly reduced plant height by »27% when compared to the untreated control, but excessively short plants were observed at 16 and 32 mg a.i./pot. Plant diameter was also significantly decreased by »16% at 2 and 4 mg a.i./pot of paclobutrazol, when compared to the untreated control. Flower diameter decreased by »4% at 2 and 4 mg a.i./pot of paclobutrazol, but only concentrations ≥4 mg a.i./pot were significantly different from the untreated control. Paclobutrazol concentrations had no effect on days from potting to flowering. Drench concentrations of 2 and 4 mg a.i./pot of paclobutrozol produced optimum height control in relation to 16.5-cm-diameter pot size used.


2010 ◽  
Vol 20 (5) ◽  
pp. 863-866 ◽  
Author(s):  
Christopher J. Currey ◽  
Diane M. Camberato ◽  
Ariana P. Torres ◽  
Roberto G. Lopez

Parboiled rice hulls have become a more common component of soilless growing substrates. While there have been reports that some organic substrate components reduce the efficacy of plant growth retardant (PGR) drenches, the influence of rice hulls on PGR drenches is unknown. ‘Callie Deep Yellow’ calibrachoa (Calibrachoa ×hybrid) and ‘Delta Orange Blotch’ pansy (Viola wittrockiana) were planted in containers filled with substrate containing (v/v) 80% peat and 20% perlite or parboiled rice hulls. After planting, 2.5-fl oz drenches containing deionized water or ancymidol, paclobutrazol, or uniconazole were applied to plants grown in each substrate. Plant growth retardants, but not substrate, affected growth rate, and final stem length of calibrachoa and plant height of pansy. There were no differences in regression model coefficients between substrates within PGR applications for plant height (pansy) or stem length (calibrachoa) over the course of the experiment. Paclobutrazol (2.0 or 4.0 ppm) and uniconazole (1.0 or 2.0 ppm), but not ancymidol (1.0 or 2.0 ppm) suppressed final stem length of calibrachoa. Final height of pansy was suppressed by each concentration of paclobutrazol and uniconazole and 2.0 ppm ancymidol, but not 1.0 ppm ancymidol. Based on these results, rice hulls did not reduce PGR drench efficacy when included as a substrate component comprising (v/v) 20% of a substrate.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 446e-447
Author(s):  
Joyce G. Latimer ◽  
Paul A. Thomas

Perennial bedding plant species were tested for response to single treatments of Sumagic (0, 15, 30, 45, or 60 ppm), Bonzi (0, 40, 80, 120, or 160 ppm), Cycocel (0, 750, 1500, 2250, or 3000 ppm) or B-Nine (5000 ppm, applied twice) applied during greenhouse production in Spring 1997. Plant height of both Chrysanthemum parthenium and Malva alcea had a quadratic response to Sumagic and Bonzi rates, with excessive height reductions at the lowest application rates at 4 weeks after treatment. All rates of Cycocel reduced plant height of C. parthenium and M. alcea by 33% and 40%, respectively. These species did not establish in the landscape. Verbena bonariensis was moderately responsive to Sumagic and Bonzi, but not Cycocel. Application rates of 15 and 30 ppm Sumagic or 160 ppm Bonzi provided moderate height control without landscape persistence beyond 4 weeks after planting. Leucanthemum × superbum `Alaska' was responsive to Sumagic and Bonzi, but not Cycocel or B-Nine. Rates of 15 ppm Sumagic or 40 ppm Bonzi provided moderate control without landscape persistence. Plant height of Monarda didyma `Blue Stocking' had a linear response to Sumagic and Bonzi rates. Plant height of Rudbeckia fulgida var. Sullivantii `Goldstrum' was reduced by Bonzi and Sumagic but not B-Nine or Cycocel, with recommended rates of 30 to 40 ppm Sumagic or 160 ppm Bonzi. Treatment of Sedum × `Autumn Joy' with Sumagic resulted in excessive landscape persistence of growth retardation at all rates, but Sedum was not responsive to Cycocel. Veronica alpina `Sunny Border Blue' was responsive to all rates of Cycocel, but growth retardation persisted through 12 weeks after planting.


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