Growth Control of ‘Taylortown Red’ and ‘Homestead Purple’ Verbena with Pistill in Nursery Production

Abstract Verbena canadensis ‘Homestead Purple’ and ‘Taylortown Red’ were treated with one or two spray applications of the plant growth regulator (PGR) Pistill (ethephon) at 0, 250, 500, 750, or 1000 ppm. Plants were in 3.8 liter (1 gal) containers under outdoor nursery conditions. Plant widths of ‘Homestead Purple’ verbena were suppressed linearly with increasing Pistill concentrations up to 24% at 2 weeks after initial treatment (WAT) and up to 18% at 4 WAT. Widths of ‘Taylortown Red’ verbena were suppressed 22% at 2 WAT with a single application at 500 to 1000 ppm, and linearly up to 33% at 4 WAT with 2 applications. Two applications of Pistill suppressed heights and widths of both cultivars at 7 WAT compared to one application.

Download Full-text

Quantifying Growth Control of Lantana Cultivars Varying in Vigor with Ancymidol, Flurprimidol, Paclobutrazol, and Uniconazole Substrate Drenches

HortTechnology ◽

10.21273/horttech.26.3.320 ◽

2016 ◽

Vol 26 (3) ◽

pp. 320-326

Author(s):

Christopher J. Currey ◽

Kellie J. Walters ◽

Kenneth G. McCabe

Keyword(s):

Plant Growth ◽

Plant Height ◽

Growth Regulator ◽

Active Ingredient ◽

Plant Growth Regulator ◽

Growth Habit ◽

Growth Control ◽

Growth Index ◽

Plant Size ◽

Lantana Camara

Our objective was to quantify the efficacy of different plant growth regulator (PGR) substrate drenches on growth of lantana (Lantana camara) cultivars varying in growth habit. Rooted ‘Little Lucky Peach Glow’, ‘Lucky Peach’, and ‘Landmark Peach Sunrise’ lantana cuttings were individually planted into 4-inch-diameter containers filled with a commercial, soilless growing substrate. Fourteen days after planting, solutions containing 0 (control), 0.5, 1, 2, or 4 mg·L−1 ancymidol, flurprimidol, paclobutrazol, or uniconazole were applied to the surface of the growing substrate. Six weeks after applying PGR drenches, data were collected. The growth index (GI), an integrated measurement of plant size incorporating the height and widths of plants, was calculated. There was variation in the GI among the control plants, reflecting variation among cultivars within the species. In addition, we measured variation in activity among the different PGRs applied. Across the concentrations applied, ancymidol generally had the lowest activity across the four PGRs. For example, drenches containing 4 mg·L−1 ancymidol resulted in plants that were similar to plants treated with 0.5 to 1 mg·L−1 flurprimidol or uniconazole or 2 mg·L−1 paclobutrazol for ‘Lucky Peach’ lantana. Across all cultivars, flurprimidol and uniconazole had the greatest activity in suppressing plant height, width, and GI. Substrate drenches containing flurprimidol, paclobutrazol, or uniconazole are useful to control size of lantana produced in containers, though the recommended concentration depends on the active ingredient and the growth habit of cultivars being treated.

Download Full-text

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

HortScience ◽

10.21273/hortsci.40.3.881f ◽

2005 ◽

Vol 40 (3) ◽

pp. 881f-882 ◽

Cited By ~ 1

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.

Download Full-text

Effects of Paclobutrazol on Royal Palm (Roystonea regia) Trunk and Height Growth

Arboriculture & Urban Forestry ◽

10.48044/jauf.2010.029 ◽

2010 ◽

Vol 36 (5) ◽

pp. 221-223

Author(s):

A.D. Ali ◽

Shawn Bernick

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Cell Elongation ◽

Plant Growth Regulator ◽

Height Growth ◽

Herbaceous Plants ◽

Single Application ◽

Date Palms ◽

Vertical Growth

Paclobturazol is a plant growth regulator which reduces cell elongation and growth. It is commonly used in reducing the growth of herbaceous plants and woody dicots. It has also shown activity against young palms, such as oil and date palms. The effects of basal drench treatments applied annually or as a single application on mature Royal palms (Roystonea regia) were studied over a three-year period. No significant effects were noted on lateral trunk growth. Paclobutrazol treatments resulted in slower vertical growth than in palms not receiving a treatment. However, even at 36 MAT, the average reduction in vertical growth (approx. 50 cm) was still not horticulturally significant relative to the overall palm height of approximately 7 m. Royal palms may attain heights up to 24 m when mature. It is recommended that they not be planted within 7 m of utility lines especially considering regulating their vertical growth is not a practical option.

Download Full-text

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

Journal of Environmental Horticulture ◽

10.24266/0738-2898-29.3.108 ◽

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).

Download Full-text

Drench Application of Cyclanilide Promotes Shoot Development in Containerized Woody Landscape Species during Nursery Production

Journal of Environmental Horticulture ◽

10.24266/0738-2898-27.4.217 ◽

2009 ◽

Vol 27 (4) ◽

pp. 217-222

Author(s):

Z. Williamson ◽

G.J. Keever ◽

J.R. Kessler ◽

J.W. Olive

Keyword(s):

Plant Growth ◽

Plant Growth Regulator ◽

Shoot Development ◽

Foliar Injury ◽

Woody Ornamentals ◽

Snow White ◽

Quality Ratings ◽

Shoot Production ◽

Nursery Production ◽

Spray Applications

Abstract Cyclanilide (CYC), a plant growth regulator with cytokinin-like properties, was applied as a substrate drench to containerized woody ornamentals to determine its effects on plant growth. At 70 days after treatment (DAT) in 2005, drench applications of 50 to 1,000 ppm CYC had increased shoot development 7 to 74% for ‘Alabama Beauty’ sasanqua camellia (Camellia sasanqua ‘Alabama Beauty’), 63 to 205% for small anisetree (Illicium parviflorum), 21 to 74% for ‘Snow White’ Indian hawthorn (Rhaphiolepis indica ‘Snow White’), and 266 to 626% for ‘Sky Pencil’ holly (Ilex crenata ‘Sky Pencil’), when compared to control plants. Shoot counts the following spring, 270 DAT, increased from 16 to 101% for sasanqua camellia, 42 to 158% for small anisetree, 121 to 241% for Indian hawthorn, and 33 to 167% for ‘Firepower’ nandina, when compared to control plants. At 30 DAT foliar injury to sasanqua camellia, Indian hawthorn, and small anisetree increased with CYC concentration, and application of 500 or 1,000 ppm CYC resulted in severe injury or death of small anisetree and ‘Snow White’ Indian hawthorn. At 75 DAT in 2006, drench application of 25 to 100 ppm CYC had increased shoot counts of Eleanor Taber™ Indian hawthorn from 100 to 218%, when compared to controls, and quality ratings were highest at 130 DAT in plants drenched with 50 ppm CYC, although foliar injury ratings increased with CYC concentration at 75 and 130 DAT. At 60 DAT in 2007, application of 10 to 40 ppm CYC had increased shoot counts for ‘Snow White’ Indian hawthorn and ‘Sky Pencil’ holly 100 to 182% and 22 to 78%, respectively, and 96 to 171% and 30 to 63%, respectively at 90 to 110 DAT. In both species, quality ratings at 160 DAT increased with increasing CYC concentration. Single CYC drench applications were more persistent than previously reported single spray applications, effective at lower concentrations, and promoted shoot production in a species not responsive to single or multiple spray applications (Nandina domestica).

Download Full-text

REDUCED RISK CONCEPT FOR PROHEXADIONE-CALCIUM, A VEGETATIVE GROWTH CONTROL PLANT GROWTH REGULATOR IN APPLES

Acta Horticulturae ◽

10.17660/actahortic.1997.451.79 ◽

1997 ◽

pp. 667-672 ◽

Cited By ~ 11

Author(s):

Victor W. Winkler

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Vegetative Growth ◽

Plant Growth Regulator ◽

Control Plant ◽

Growth Control ◽

Prohexadione Calcium ◽

Reduced Risk ◽

Risk Concept

Download Full-text

Growth Regulation of Russian Sage During Greenhouse and Nursery Production

Journal of Environmental Horticulture ◽

10.24266/0738-2898-19.1.24 ◽

2001 ◽

Vol 19 (1) ◽

pp. 24-28

Author(s):

S.E. Burnett ◽

G.J. Keever ◽

C.H. Gilliam ◽

J.R. Kessler

Keyword(s):

Plant Growth ◽

Growth Response ◽

Growth Regulation ◽

Treatment Effects ◽

Growth Control ◽

Effective Rate ◽

Growth Retardants ◽

Nursery Production ◽

Outdoor Nursery ◽

Effective Growth

Abstract Growth response of Perovskia atriplicifolia (Russian sage) treated with several plant growth retardants (PGRs) was determined under three production regimes: 1) small plants in 10 cm (4 in) pots grown in a greenhouse and half transplanted into the landscape at 6 weeks after treatment (WAT), and 2) large plants grown in 3.8 liter (#1) pots in a greenhouse or 3) in an outdoor nursery. Plants in 3.8 liter (#1) pots were not transplanted into the landscape. Treatments included Cutless at 50, 100 and 150 ppm; Sumagic at 20, 40 and 60 ppm; B-Nine/Cycocel tank mixes at 2,500/1,500, 5,000/1,500 and 7,500/1,500 ppm; Pistill at 500 and 1,000 ppm; and a non-treated control. All PGRs controlled plant growth through 6 WAT in the greenhouse and 2 weeks after planting. At this time (8 WAT), plants treated with the most effective rate of Cutless (150 ppm), Sumagic (20, 40, or 60 ppm), B-Nine/Cycocel tank mixes (5,000 ppm/1,500 ppm), and Pistill (500 or 1,000 ppm) were 32%, 32%, 25%, and 32% smaller in 10 cm (4 in) pots and 21%, 22%, 22%, and 16% smaller in 3.8 liter (#1) pots, respectively, compared to non-treated controls. Treatment effects were non-significant by 4 weeks after plants grown in the greenhouse in 10 cm (4 in) pots for 6 weeks were transplanted into the landscape (10 WAT). Plants in 3.8 liter (#1) pots in the greenhouse were significantly smaller, excluding those treated with Pistill, than non-treated controls at 12 WAT; at this time, the most effective rate of Cutless (150 ppm), Sumagic (40 ppm), and B-Nine/Cycocel tank mixes (5,000 ppm/1,500 ppm) suppressed growth 21%, 23%, and 26%, respectively. For 3.8 liter (#1) pots in the nursery, Cutless suppressed growth 5–11% at 2 WAT only, and the most effective rate of Sumagic (60 ppm) reduced growth 7% at 4 WAT, but not thereafter. The most effective rates of B-Nine/Cycocel (7,500 ppm/1,500 ppm) and Pistill (1,000 ppm) suppressed growth 13% and 10%, respectively, at 8 WAT. Results suggest that PGR effectiveness is less outdoors under nursery conditions than in the greenhouse, particularly for Cutless and Sumagic. The duration and magnitude of B-Nine/Cycocel treatment effects suggest that this PGR combination may provide the most effective growth control of Russian sage under nursery conditions.

Download Full-text