Effects of maturation and gibberellin A4/7 on flowering and branching characteristics of Larixlaricina

1993 ◽  
Vol 23 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Throstur Eysteinsson ◽  
Michael S. Greenwood
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Second Order ◽  
Flowering Response ◽  
Foliar Sprays ◽  
Female Flowering

Flowering and the flowering response to the plant growth regulator gibberellin (GA4/7) were assessed on potted, greenhouse-grown tamarack (Larixlaricina (Du Roi) K. Koch) grafts made from ortets aged 1 to 74 years. Female flowering decreased with ortet age, whereas male flowering remained similar, resulting in an increased proportion of pollen cones with age. The decrease in total flowering with age was not adequately explained by smaller size or lower vigor of the older scions. Scions from the youngest ortets produced more, but shorter, second-order branches than scions from older ortets. GA4/7, applied in foliar sprays beginning at the start of long-shoot extension, resulted in increased flowering of both sexes, with a proportionately greater increase in female flowering by scions from younger ortets but a roughly equal increase in flowering of both sexes by scions from the oldest ortets. Furthermore, the overall flowering response to GA4/7 (proportionate to control) increased with ortet age. GA4/7 did not affect branch terminal increment, but did increase overall second-order lateral increment slightly.

Promotion of flowering in young Larixlaricina grafts by gibberellin A4/7 and root pruning

1990 ◽  
Vol 20 (9) ◽  
pp. 1448-1452 ◽  
Author(s):  
Throstur Eysteinsson ◽  
Michael S. Greenwood
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Shoot Elongation ◽  
Root Pruning ◽  
Mature Trees ◽  
Foliar Sprays ◽  
Female Flowering

Flowering was promoted on potted, indoor, and field-grown 3-year-old juvenile and mature Larixlaricina (Du Roi) K. Koch grafts by foliar sprays of the plant-growth regulator gibberellin A4/7 and root pruning. Biweekly gibberellin A4/7 applications of three different durations, commencing at the start of long-shoot elongation, yielded similar increases in female flowering in the greenhouse; this effect was synergistically enhanced by root pruning. Male flowering was promoted by gibberellin A4/7 + root pruning in mature but not juvenile grafts. In the field, female flowering was also promoted by the gibberellin A4/7 treatment commencing at the start of shoot extension, but gibberellin A4/7 applications starting later were not effective. Grafted scions from mature trees responded significantly better to gibberellin A4/7 + root pruning than did seedling scions.

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 EFFICACY OF FLURPRIMIDOL (TOPFLOR) ON WARM-SEASON BEDDING PLANTS

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 881f-882 ◽  
Author(s):  
James L. Gibson ◽  
Shannon Crowley
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Growth Control ◽  
Warm Season ◽  
Retail Sales ◽  
Bedding Plants ◽  
Foliar Sprays ◽  
Bedding Plant ◽  
Portulaca Grandiflora

The objective of this study was to compare the effects of flurprimidol or paclobutrazol on the growth of four bedding plant species: nicotiana (Nicotiana ×sanderae), portulaca (Portulaca grandiflora), verbena (Verbena ×hybrida), and zinnia (Zinnia elegans). Plants were treated 10 days after transplanting with foliar sprays of five concentrations (in mg·L–1): 5, 10, 20, 40, or 80 from each plant growth regulator. Phytotoxicity symptoms were not observed on plants sprayed with flurprimidol or paclobutrazol. Foliar sprays of flurprimidol at 20 mg·L–1 and paclobutrazol at 80 mg·L–1 provided sufficient growth control of nicotiana for retail sales, while concentrations of 40 to 80 mg·L–1 flurprimidol produced more compact plants for wholesale production. For portulaca only flurprimidol sprays of 40 and 80 mg·L–1 produced plants that were proportionate to the container. Foliar sprays of flurprimidol at 20 mg·L–1 and paclobutrazol at 40 mg·L–1 controlled growth of verbena and zinnia suitable for retail sales, while concentrations of 40 mg·L–1 flurprimidol and 80 mg·L–1 paclobutrazol provided more compact plants which may be useful for wholesale growers. Concentrations were based under Florida conditions and should be adjusted for other areas.

scholarly journals Flurprimidol Substrate Drenches and Foliar Sprays Control Growth of `Blue Champion' Exacum

2006 ◽  
Vol 16 (2) ◽  
pp. 354-356
Author(s):  
Brian E. Whipker ◽  
Ingram McCall ◽  
Brian A. Krug
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Untreated Control ◽  
Foliar Spray ◽  
Foliar Sprays ◽  
Control Growth ◽  
Exacum Affine

Flurprimidol was applied as a foliar spray (12.5, 25.0, 37.5, 50.0, or 62.5 mg·L-1) or as a substrate drench (0.015, 0.03, 0.06, 0.12, or 0.24 mg/pot a.i.) to determine its efficacy on `Blue Champion' exacum (Exacum affine). Flurprimidol substrate drenches were more consistent in controlling plant growth than foliar sprays. Substrate drenches of 0.03 mg/pot a.i. or foliar sprays ≥50 mg·L-1 resulted in smaller plant heights and diameters than the untreated control. With the use of flurprimidol, exacum growers have another plant growth regulator (PGR) available to control excessive growth.

scholarly journals Gibberellic acid in vegetative and reproductive development of Phalaenopsis orchid hybrid genus

2012 ◽  
Vol 30 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Jean C Cardoso ◽  
Elizabeth O Ono ◽  
João D Rodrigues
Keyword(s):  
Plant Growth ◽  
Gibberellic Acid ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Reproductive Development ◽  
Foliar Sprays ◽  
Low Concentrations ◽  
Flowering Control ◽  
Flower Quality

The flower industry represents about one billion dollars in Brazil and the development of techniques aimed at flowering control is required. This study evaluated the influence of gibberellic acid (GA3) on the vegetative and reproductive development of young plants of Phalaenopsis FSNT 'Dai-Itigo' hybrid pink color. The application of GA3 was made by foliar sprays at concentrations of 0, 125, 250, 500 and 1,000 mg L -1. The length of leaves increased significantly when using GA3 at low concentrations, but leaf width decreased. The application of GA3 at 125 mg L -1 showed the best results for the promotion of flowering and flower quality of this orchid hybrid. In this treatment, about 50% of plants treated with GA3 flowered about 6-12 months before the plants that were non-treated with this plant growth regulator. The quality of flowering and flowers was best with 125 mg L -1 GA3.

scholarly journals Cyclanilide Promotes Shoot Production and Flowering of Coreopsis and Coneflower during Nursery Production

2011 ◽  
Vol 29 (3) ◽  
pp. 108-114
Author(s):  
M.E. Farris ◽  
G.J. Keever ◽  
J.R. Kessler ◽  
J.W. Olive
Keyword(s):  
Plant Growth ◽  
Plant Development ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Shoot Development ◽  
Herbaceous Perennials ◽  
Foliar Sprays ◽  
Concentration Method ◽  
Shoot Production ◽  
Nursery Production

Abstract Herbaceous perennials were screened for increased branching and flowering in response to foliar sprays of cyclanilide (CYC), a plant growth regulator with cytokinin-like activity. Coreopsis verticillata ‘Creme Brulee’ (‘Crème Brulee’ coreopsis) and Rudbeckia fulgida ‘Goldsturm’ (‘Goldsturm’ coneflower), the only two species that responded positively to CYC, were used in subsequent experiments evaluating CYC concentration, method of application, and stage of plant development at application. Foliar sprays of 25 to 100 ppm CYC promoted increased shoot development, flowering, and plant width of coreopsis and coneflower, although flowering was delayed. Applying foliar sprays to both species when they were vegetative resulted in similar or more new shoots and flowers than an application when plants exhibited early signs of approaching flowering or at both stages. Increases in shoot counts from the application of substrate drenches of CYC to coreopsis and coneflower generally were less than from foliar sprays, while flower counts either decreased with increasing CYC concentration (coreopsis) or were unaffected (coneflower).

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 250 Ornamental Cabbage and Kale Growth Response to Plant Growth Regulators

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 434B-434 ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker
Keyword(s):  
Plant Growth ◽  
Brassica Oleracea ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Untreated Control ◽  
Growth Response ◽  
Foliar Sprays ◽  
Industry Standard ◽  
The Cost

Ornamental cabbage and kale (Brassica oleracea var. acephala L.) plants of cultivars `Osaka White' and `Nagoya Red' were treated with paclobutrazol and uniconazole as foliar sprays or soil drenches. These treatments were compared to the industry standard of daminozide foliar sprays. Ten plant growth regulator (PGR) drench treatments (in mg a.i./pot) were applied 22 days after potting: paclobutrazol at 1 to 16 and uniconazole at 0.125 to 2. Thirteen PGR foliar sprays (in mg/L) were also applied: paclobutrazol at 5 to 80, uniconazole at 2 to 32, daminozide at 2500, 2500 (twice, with the second application occurring 14 days later), or 5000, and an untreated control. Applying drenches of paclobutrazol at 4 mg or uniconazole at 0.5 mg controlled height by 16 to 25%, but at the cost of $0.11 per pot would not be economically feasible for growers to use. Paclobutrazol foliar sprays at concentrations of up to 80 mg/L were ineffective in controlling plant height and diameter of either `Osaka White' or `Nagoya Red'. Uniconazole foliar sprays between 2 and 8 mg/L were effective in controlling height (by 19%) and diameter (by 15%) as daminozide foliar sprays of 2500 mg/L, sprayed twice, with a cost to the grower of $0.02 per pot.

Influence of plant growth regulator and rhizobial inoculation on nodulation and soybean nitrogen contant

2007 ◽  
Vol 35 (2) ◽  
pp. 993-996 ◽  
Author(s):  
Sulejman Redžepović ◽  
Sanja Sikora ◽  
Josip Čolo ◽  
Mihaela Blažinkov ◽  
Marija Pecina
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Rhizobial Inoculation
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