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 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 Dark-stored Flurprimidol Solutions Maintain Efficacy Over Many Weeks

HortScience ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 77-81 ◽  
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.

PLANT GROWTH REGULATOR ACTIVITY OF SOLUBLE HUMIC COMPLEXES

1984 ◽  
Vol 64 (2) ◽  
pp. 225-228 ◽  
Author(s):  
G. CACCO ◽  
G. DELL’AGNOLA
Keyword(s):  
Biological Activity ◽  
Plant Growth ◽  
Key Words ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Good Evidence ◽  
High Concentration ◽  
Stem Curvature ◽  
Cytokinin Bioassays

Auxin and cytokinin bioassays were performed to test the biological activity of soluble humic complexes (SHC). "Pea split stem curvature" (auxin test) and "cucumber" tests (cytokinin test) did not show any quantifiable biological activity of SHC. On the contrary, "cress test" and "senescence test" offered good evidence of a hormonal-like activity 100 times lower than that of IAA (10 mg IAA∙g−1 SHC) and 10 times lower than that of N6 BA (100 mg N6 BA∙g−1 SHC). At a high concentration of SHC, toxic effects were evident, indicating the presence of inhibitory substances which counteracted the hormone-like activity of humic complexes. Key words: Plant growth regulators, soluble humic complexes

Effect of Azorhizobium caulinodans on yield in plant growth regulator induced nodulated wheat

2017 ◽  
Vol 2 (01) ◽  
pp. 24-27
Author(s):  
Reena Tomer ◽  
S. P. Singh ◽  
Varun Tomer ◽  
Mahesh Kumar ◽  
Nidhi Sharma
Keyword(s):  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Wheat Variety ◽  
Azorhizobium Caulinodans ◽  
Wheat Seedlings ◽  
Hoagland Solution ◽  
Maximum Photosynthetic Rate ◽  
Pot Culture

In the laboratory seedling were induced with nodule-like outgrowths using different growth regulators 2,4-D,IBA and NAA in nitrogen free Hoagland solution. Induced seedlings were inoculated with Azorhizobium caulinodans (ORS 571) in wheat variety C-306. One set was also raised as control. The treated paranoulated wheat seedlings were transferred to pot culture. The data was collected on 30, 60 and 90 days after sowing, which reveals that as a Azorhizobium caulinodans with 2,4-D treated plants shows maximum photosynthetic rate followed by NAA and IBA combinations. The biomass production was maximum in Azorhizobium caulinodans treated with 2,4-D followed by IBA and NAA.

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 Poinsettia Stem Strength

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 484A-484 ◽  
Author(s):  
Jeff S. Kuehny ◽  
Patricia Branch
Keyword(s):  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Nitrogen Fertilizer ◽  
Plant Growth Regulator ◽  
Main Stem ◽  
Stem Strength ◽  
Lateral Branches ◽  
Fertilizer Rates ◽  
Drip Fertigation

Lateral branches of poinsettia tend to break from the main stem as plants reach maturity. The cause of poor stem strength is not known; however, suggested factors implicated in poor stem strength are: rate of nitrogen fertilizer used, type of plant growth regulator used, crowding of plants, or stem diameter of the cutting. Four different experiments were conducted to determine if these factors affected stem strength of poinsettia. Experiment 1: `Freedom Red', `Success', `V-17 Angelika Red', `Red Sails', `Nutcracker Red', `Cortez', `Maren', and `Red Splendor' poinsettia were fertilized with 20N–1P0–20K at 75, 75/125, 125/200, or 200 ppm N drip fertigation with zero leachate. Experiment 2: Three plant growth regulators were applied to `Pearl' and `Jolly Red' poinsettias. Experiment 3: `Freedom Red' plants were grown in a 625, 900, 1225, or 1600 cm2 area. Experiment 4: Rooted `Freedom Red' cuttings with stem diameters of 4.5, 5.5, 6.5, or 7.5 mm were used. A force meter was used to determine the strength of each lateral on the main stem of the six replications in each experiment. The lower laterals had the least stem strength and the top lateral had the highest stem strength for all treatments in all experiments. The stem strengths of some cultivars in experiment 1 were stronger at the lower fertilizer rates. Type of plant growth regulator had no significant affect on most poinsettia cultivars. The stem strengths of poinsettias in experiments 3 and 4 varied according to which lateral was measured.

scholarly journals USE OF FORCING SOLUTIONS TO STUDY PLANT GROWTH REGULATOR EFFECTS ON VANHOUTTE'S SPIRAEA CULTURED IN VITRO

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1124e-1124
Author(s):  
Guochen Yang ◽  
P. E. Read
Keyword(s):  
Plant Physiology ◽  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Woody Plant ◽  
Shoot Proliferation ◽  
Plant Tissues ◽  
Forcing Solution

Vanhoutte's spiraea has been propagated in vitro using explants from softwood growth of dormant stems forced in a solution containing 200 mg/l 8-hydroxyquinoline citrate (8-HQC) and 2% sucrose (Yang and Read, 1989). Objectives to further utilize this system were to determine the feasibility of applying plant growth regulators (PGR) via the forcing solution to softwood growth from forced dormant stems and to study the resulting influence on in vitro culture. BA and GA3 were placed in the forcing solution at various concentrations, including a zero PGR control. Explants were cultured on Linsmaier and Skoog (LS) medium containing zero PGR or different amounts of BA or thidiazuron (TDZ) or combinations of BA and IAA. Control explants placed on LS medium supplemented with 5uM BA with or without 1 or 5uM IAA, or with 0.5 or 0.75 uM TDZ alone produced the best shoot proliferation. BA in the forcing solution stimulated micropropagation, while GA3 caused less proliferation than explants from control solutions. Forcing solutions containing PGR are useful for manipulating responses of plant tissues cultured in vitro and for studying PGR influence on woody plant physiology.

scholarly journals Ornamental Cabbage and Kale Cultivar Comparison Study: Growth Characteristics and Response to Daminozide and Uniconazole Sprays

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 565E-565d ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Brassica Oleracea ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Color Change ◽  
Growth Characteristics ◽  
Comparison Study ◽  
Effective Height ◽  
Height Control ◽  
Ornamental Kale

Twenty-six ornamental cabbage and kale (Brassica oleracea var. acephala L.) cultivars were transplanted into 20.8-cm (8-inch) pots in Fall 1998 to classify their foliage traits and determine their response to the plant growth regulator (PGR) daminozide. Daminozide foliar sprays were applied at 0, 2500, or 5000 mg·L–1 (ppm) 3 weeks after potting. Two cultivars treated with 2500 mg.L-1 and eight cultivars treated with 5000 mg·L–1 were significantly smaller in height when compared to the nontreated plants. Using the Range/lsd formula, the vigor of the cultivars was classified by height. Foliage characteristics were described and cultivars of ornamental cabbage, notched ornamental kale, and curly ornamental kale were selected based on the shortest number of days until a significant center color change and the largest center color diameter. In Fall 1999, recommended cultivars selected in 1998 were treated with daminozide at 5000 mg·L–1 or uniconazole at 5 mg·L–1 14 days after potting, plus a nontreated control. All cultivars responded similarly to the PGRs with greater control being observed with daminozide with a smaller plant height of 13% as compared to 6% for uniconazole. For effective height control, PGR applications to ornamental cabbage and kale should be applied 2 weeks after potting.

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.

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