scholarly journals Plant Growth Retardant Drench Efficacy Is Not Affected by Substrate Containing Parboiled Rice Hulls

2010 ◽  
Vol 20 (5) ◽  
pp. 863-866 ◽  
Author(s):  
Christopher J. Currey ◽  
Diane M. Camberato ◽  
Ariana P. Torres ◽  
Roberto G. Lopez
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Final Height ◽  
Organic Substrate ◽  
Growth Retardant ◽  
Stem Length ◽  
Common Component ◽  
Parboiled Rice ◽  
Rice Hulls ◽  
Deep Yellow

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.

scholarly journals Response of Easter Lily to Preplant Incorporation of Uniconazole into the Planting Medium

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 152-154 ◽  
Author(s):  
Richard J. McAvoy
Keyword(s):  
Plant Growth ◽  
Final Height ◽  
Lilium Longiflorum ◽  
Stem Length ◽  
Effective Height ◽  
Treatment Groups ◽  
Height Control ◽  
Potting Medium ◽  
Easter Lily ◽  
Shoot Emergence

Lilium longiflorum Thunb. cv. Ace grown without plant growth regulators and plants drenched with 0.5 mg a.i. ancymidol per pot following shoot emergence were compared to plants growing in a medium containing uniconazole-impregnated amendments. Uniconazole was applied at rates of 0.18, 0.018, and 0.0018 mg a.i. per pot using either impregnated rockwool (RW) or copolymer acrylamide acrylate (CA). Two other treatment groups received a uniconazole drench at potting (0.018 or 0.0018 mg a.i. per pot). Impregnated CA resulted in undesirably short lilies (i.e., plants <1.5 times the height of the pot) when 0.18 mg uniconazole per pot was incorporated into the medium; effective height control was obtained with CA at 0.018 mg/pot; no height control was observed at 0.0018 mg/pot. Similarly, final height of lilies grown in medium containing uniconazole-impregnated RW decreased as the rate of uniconazole increased. Pre-emergence potting medium drenches with uniconazole (0.018 and 0.0018 mg a.i. per pot) did not significantly affect lily growth and flowering. Ancymidol drench was less effective at retarding stem length and plant height than medium incorporation of 0.18 mg uniconazole. Flowering was not significantly affected by any treatment. Chemical names used: a-cyclopropyl-a-(4-methoxy-phenyl)-5-pyriimidine methanol(ancymidol);B-[(4-cyclophenyl)methyl]-a-(1,1-dimethylethyl)1 H-1,2,4-triazole-1-ethanol(paclobutrazol);(E)-(p-chloro-phenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol(uniconazole).

scholarly journals Pot Sunflower Growth and Flowering Responses to Foliar Applications of Daminozide, Paclobutrazol, and Uniconazole

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438D-438
Author(s):  
Brian E. Whipker ◽  
Shravan Dasoju
Keyword(s):  
Plant Growth ◽  
Helianthus Annuus ◽  
Plant Height ◽  
Foliar Spray ◽  
Growth Retardant ◽  
Height Control ◽  
Foliar Sprays ◽  
Treatment Interaction ◽  
Total Plant

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.

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 Evaluation of Carnation Cultivars; and Nitrogen and Indole Acetic Acid for Their Growth, Yield and Quality in Khumaltar, Nepal

2019 ◽  
pp. 1-6
Author(s):  
Amar Bahadur Pun Magar
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Mineral Nutrition ◽  
Block Design ◽  
Foliar Spray ◽  
Stem Length ◽  
Research Division ◽  
Flower Yield ◽  
Stem Straightness ◽  
Flower Stem

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.

scholarly journals Efficacy of Paclobutrazol Drenches on Growth of Potted Sunflowers Grown in 16.5-cm Pots

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438C-438
Author(s):  
Shravan K. Dasoju ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Helianthus Annuus ◽  
Plant Height ◽  
Untreated Control ◽  
Growth Retardant ◽  
Height Control ◽  
Pot Size ◽  
Optimum Height ◽  
Flower Diameter ◽  
Pot Plant

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.

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
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Foliar Spray ◽  
Echinacea Purpurea ◽  
Growth Retardant ◽  
Maximum Height ◽  
Bedding Plants ◽  
Phlox Paniculata ◽  
Monarda Didyma ◽  
Alcea Rosea

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

scholarly journals Persistent Effects of Plant Growth Regulators on Landscape Performance of Seed Geraniums

1994 ◽  
Vol 12 (3) ◽  
pp. 150-154
Author(s):  
Joyce G. Latimer ◽  
Sherrod A. Baden
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Dry Weight ◽  
Stem Length ◽  
Shoot Dry Weight ◽  
Landscape Performance ◽  
Reduced Height ◽  
Time Required

Abstract In 1988, spray applications of 3.5 or 7 ppm paclobutrazol, 1500 ppm chlormequat, or 200 ppm ancymidol were applied to seed geraniums (Pelargonium x hortorum L. H. Bailey ‘Ringo White’ and ‘Ringo Rose’) to determine effects on growth in the greenhouse and the subsequent growth and performance of treated plants in the landscape. All growth retardants reduced stem length and shoot dry weight as well as time required for flowering, while branching was increased relative to the untreated plants. Flowering in the landscape was increased by all growth regulator treatments at 4 weeks after planting but was generally not different from the untreated plants at 6 weeks after planting. Plant height and width were reduced by all treatments for both cultivars, relative to untreated plants, at 4 weeks after planting. However, only 7 ppm paclobutrazol reduced height and width of ‘Ringo White’ plants at 6 weeks after planting. Plant height, but not width, was reduced by all treatments for ‘Ringo Rose’ at 6 weeks after planting. In 1989, seedlings of ‘Ringo Rose’ were treated with 3.5, 7, 16, 40, or 80 ppm paclobutrazol or 1500 ppm chlormequat or 200 ppm ancymidol. Seedling growth was excessively reduced by 40 or 80 ppm paclobutrazol. Time required for flowering was not reduced by growth regulators in 1989. Landscape performance under conditions of excess rain was not improved by plant growth regulators and the height of plants treated with 16, 40 or 80 ppm paclobutrazol was still less than that of the untreated plants at 12 weeks after planting. Only chlormequat controlled plant growth in the greenhouse without delaying the resumption of growth in the landscape.

scholarly journals Plant Growth Retardant and Initial Plant Height Affect Canna Lily Growth and Flowering

2001 ◽  
Vol 19 (4) ◽  
pp. 180-183
Author(s):  
L.L. Bruner ◽  
G.J. Keever ◽  
J.R. Kessler ◽  
C.H. Gilliam
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Vegetative Growth ◽  
Growth Retardant ◽  
Minimal Effect

Abstract A study conducted in 2000 determined effects of two rates of Cutless and B-Nine/Cycocel tank mix and initial plant height on vegetative growth and flowering of Canna x generalis ‘Florence Vaughan’. Canna lily responded independently to plant growth retardant (PGR) treatment and initial plant height. Cutless suppressed vegetative height consistently up to 34% at the lower rate (25 ppm) and up to 41% at the higher rate (50 ppm) throughout the study, regardless of initial plant height. At first and second flower, increasing rates of Cutless suppressed vegetative height about 36% and 35–40%, respectively, and first and second flowering heights, 39–52% and 36–47%, respectively, with minimal effect on time to flower. Height suppression from B-Nine/Cycocel treatments was less than from Cutless with the greatest suppression, 12%, occurring at first flower. Differences in vegetative height among short, intermediate, and tall plants were most significant at treatment, decreased thereafter, and were not present 60 days after treatment (DAT). The number of days to first and second flower was affected by initial plant height with shorter plants flowering 10 to 15 days later than taller plants. At first flower, vegetative height of the initially tall plants was greatest, followed in succession by plants intermediate and short at treatment. However, by second flower, vegetative heights of plants, which were initially short and intermediate in height, were greatest, followed by tall plants. At first flower, flowering heights of all plants were similar and at second flower, flowering heights of the initially tall plants were slightly less [5–6 cm (1.9–2.3 in)] than those of intermediate and short plants.

scholarly journals Bulking Duration and Daminozide Affect Growth and Flowering of Achillea בCoronation Gold’

2015 ◽  
Vol 33 (2) ◽  
pp. 84-88
Author(s):  
Mohan Li ◽  
J. Raymond Kessler ◽  
Gary J. Keever ◽  
Wheeler G. Foshee
Keyword(s):  
Plant Growth ◽  
Foliar Spray ◽  
Growth Retardant ◽  
Main Stem ◽  
Stem Length ◽  
Flower Buds ◽  
Flower Bud ◽  
Open Flower ◽  
Single Shoot

A study was conducted to determine the effects of bulking duration and the plant growth retardant daminozide on plant growth and flowering of greenhouse-grown ‘Coronation Gold’ yarrow (Achillea בCoronation Gold’). Single-shoot liners of yarrow were transplanted on October 14 and December 2, 2010, into 15 cm (6 in) containers and bulked for 4, 6, 8, or 10 weeks prior to exposure to night-interrupted lighting (NIL). Increasing the bulking duration increased the number of shortened, thickened stems of rosette-like appearance, or offsets, that had developed from the base of the main stem by the end of bulking by 100 to 367% and reduced days to first and five open inflorescences, hereafter referred to as flowers, from the beginning of NIL by 13 to 16 days and 10 to 20 days for the October and December potting dates, respectively. Increasing the bulking duration increased flower and flower bud number by 67 and 25% in the October 14 and December 2 potting dates, respectively. Therefore, more flowers and flower buds formed on yarrow when potted early, compared to late potting. Lengths of the first five open flower stems were inconsistent and minimally affected by bulking duration. In a repeat of the experiment potted on December 2 using the same bulking treatments, 5,000 ppm of daminozide was applied as a foliar spray when half the plants in a bulking duration had begun to elongate and was reapplied 1 week later. Daminozide application decreased stem length at first open flower by 20 to 43%, but increased days to first flower and five open flowers by 6 and 8 days, respectively. As in the first experiment, increasing the bulking duration increased the number of offsets and flower and flower bud number and reduced days to first and five open flowers.

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