scholarly journals Photoperiod of Poinsettia Stock Plants Influences Rooting of Cuttings

1997 ◽  
Vol 7 (1) ◽  
pp. 41-43
Author(s):  
Michael J. Roll ◽  
Steven E. Newman
Keyword(s):  
Flower Initiation ◽  
Euphorbia Pulcherrima ◽  
Root Mass ◽  
Stock Plant ◽  
Critical Daylength ◽  
Plant Stage ◽  
Rooting Of Cuttings

Rooting of cuttings from three cultivars of Euphorbia pulcherrima Willd. was evaluated after regulating the photoperiod during the stock plant stage. One group of stock plants was exposed to a night break (4 hours) and another group was exposed to natural daylength during September. Cuttings harvested in late September from `Freedom Red' and `Monet' stock plants grown under the 4-hour night break rooted more rapidly and had greater root mass than `Freedom Red' and `Monet' grown under natural daylength, whereas rooting of cuttings from `V-17 Angelika Marble' was not influenced by the photoperiods tested. Using a night break to prevent flower initiation of stock plants produced a higher-quality cutting when propagation took place after the critical daylength for flowering had passed.

scholarly journals Photoperiod of Poinsettia Stock Plants Influences Adventitious Rooting of Cuttings

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 567a-567
Author(s):  
Michael J. Roll ◽  
Steven E. Newman
Keyword(s):  
Dry Weight ◽  
Adventitious Rooting ◽  
Day Length ◽  
Root Weight ◽  
Flower Initiation ◽  
Stock Plant ◽  
Root Dry Weight ◽  
Plant Stage ◽  
Rooting Of Cuttings

The rooting efficiency of cuttings from three poinsettia cultivars were evaluated after regulating the photoperiod during the stock plant stage. `Freedom Red', `Monet', and `V-17 Angelika Marble' stock plants were exposed to an extended photoperiod and to natural day length during September 1995. `Freedom Red' cuttings rooted more quickly under an extended photoperiod compared to those under natural day length. Furthermore, root dry weight from these cuttings was greater than cuttings from stock plants grown under natural day length. `Monet' cuttings also rooted more quickly when the stock plants were under an extended photoperiod, and showed similar differences in root weight as `Freedom Red'. Cuttings from `V-17 Angelika Marble' were not influenced by photoperiod. Lighting stock plants to block flower initiation produces a higher quality cutting when propagation takes place after the critical day length for flowering has passed.

Photoperiod and Temperature Influence on Flower Initiation and Development for Euphorbia pulcherrima Grown Under Florida Conditions

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509a-509
Author(s):  
C.E. Wieland ◽  
J.E. Barrett ◽  
D.G. Clark ◽  
G. J. Wilfret
Keyword(s):  
Subsequent Development ◽  
Flower Initiation ◽  
Euphorbia Pulcherrima ◽  
Floral Initiation ◽  
Temperature Influence ◽  
Average Temperature ◽  
Long Day ◽  
Time To Initiation ◽  
Growth Room ◽  
Maximum Temperatures

Four poinsettia cultivars were grown in glass greenhouses in Gainesville, Fla., in the Fall 1997 to evaluate differences in floral initiation and subsequent development. Three means of regulating photoperiod were 1) natural days 2) long-day lighting to 6 Oct. and then natural days (lights out) 3) long-day lighting to 6 Oct., and then short-day conditions by black cloth for 15 h (black cloth). At 2-day intervals, sample meristems were collected and examined for initiation of reproductive development. Average minimum and maximum temperatures during the first two weeks of October were 22 and 29 °C, respectively, with an average temperature of 25.3 °C. The overall average temperature was 23.2 °C from planting to anthesis. Differences in anthesis dates among cultivars were primarily due to time to initiation vs. rate of development. Under natural days, `Lilo' initiated first on 8 Oct. and `Freedom', `Peterstar', and `Success', followed by 6, 8, and 18 days, respectively. Lights out resulted in `Lilo' initiating 17 Oct., followed by `Freedom', `Peterstar', and `Success' initiating 7, 12, and 15 days later, respectively. Differences between cultivars in time of initiation was reduced under black cloth, where `Lilo' initiated 14 Oct., followed by `Freedom' 2 days later, and `Peterstar' and `Success' 7 days afterward. Initiation was positively correlated to visible bud and anthesis. First color was positively correlated to initiation and visible bud, with the exception of `Lilo'. Growth room studies conducted using various high temperatures and photoperiods indicated similar trends.

Flowering in Townsville lucerne (Stylosanthes humilis). 1. Studies in controlled environments

1967 ◽  
Vol 7 (29) ◽  
pp. 489 ◽  
Author(s):  
DF Cameron
Keyword(s):  
Light Intensity ◽  
The Other ◽  
Flower Initiation ◽  
Night Temperature ◽  
Short Day ◽  
Critical Daylength ◽  
Stylosanthes Humilis ◽  
Controlled Environments ◽  
Lower Light ◽  
Main Factor

The flowering of seven selections of Townsville lucerne (Stylosanthes humilis HBK) representing a range of maturity types has been studied in the Canberra phytotron. Daylength is the main factor controlling flowering in these selections, all of which showed a strong short day response. At normal temperatures the maximum daylengths at which all plants flowered (the critical daylengths) were 13 hours for the early, 12 hours for the midseason and late-midseason, and 11 1/2 hours for the late selections. However, the midseason selections did flower in a 12 1/2-hour daylength if the light intensity of the supplementary illumination was 20 or 5 ft.c. instead of the normal 50 ft.c. The response of the other selections was not altered at the lower light intensities. Both high night temperature and low day temperature delayed or inhibited flower initiation in the early and midseason selections and these effects were greater at a critical daylength.

scholarly journals Using Paclobutrazol to Control Height of Poinsettia `Freedom'

2002 ◽  
Vol 12 (2) ◽  
pp. 232-236 ◽  
Author(s):  
Genhua Niu ◽  
Royal Heins ◽  
Will Carlson
Keyword(s):  
Plant Height ◽  
Stem Elongation ◽  
Flower Initiation ◽  
Euphorbia Pulcherrima ◽  
Application Time ◽  
Growth Retardants ◽  
Height Control ◽  
Area Reduction ◽  
Crop Development ◽  
Short Days

Late-season height control of poinsettia (Euphorbia pulcherrima) is difficult since most chemical growth retardants adversely reduce bract size when applied after first bract color. Paclobutrazol (Bonzi) controls stem elongation late in poinsettia crop development but can excessively reduce bract size if improperly applied. Two experiments were conducted to quantify how paclobutrazol application influenced height and bract area of `Freedom' poinsettia. In the first experiment, paclobutrazol was applied at 1 mg·L-1 (ppm) in 118-mL (4.0-fl oz) volumes per pot [(a.i.) 0.12 mg/pot (28,350 mg = 1.0 oz)] as a drench to a new group of plants weekly from the initiation of short days until 1 week before anthesis. Maximum reduction in height and bract area was obtained when paclobutrazol was applied immediately after short days, and the response to paclobutrazol decreased as application time was increasingly delayed toward anthesis. In the second experiment, paclobutrazol was applied weekly after first bract color as either a drench or subapplication at various concentrations. Plant height and bract area were reduced by 23% when 2 mg·L-1 [(a.i.) 0.24 mg/pot) paclobutrazol was applied through subapplication at first color. The effects of paclobutrazol on height and bract area reduction decreased as application time was progressively delayed. Concentrations lower than 1 mg·L-1 had no significant effect on height or bract area reduction, regardless of application time or method. Generally, the reduction in height and bract area was larger when paclobutrazol was applied through subapplication. The combined results from both experiments indicate that paclobutrazol drench applications after flower initiation concomitantly reduce plant height (internode extension) and bract area. Therefore, drench applications should be delayed as long as possible to limit reduction in bract size.

Application of Photoperiodic Manipulation in Vegetative Specialty Floral Crop Propagation and Flowering

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 554d-554
Author(s):  
Millie S. Williams ◽  
Terri Woods Starman
Keyword(s):  
Flowering Time ◽  
Flower Development ◽  
Vegetative Growth ◽  
Plant Production ◽  
Flower Initiation ◽  
Stock Plant ◽  
Flower Number ◽  
Open Flower ◽  
Long Day ◽  
Photoperiodic Responses

Photoperiod requirements are important for optimum flower development, decreasing production time, year-round flowering, and/or for increasing vegetative growth necessary in stock plant production. The photoperiodic responses were determined for 24 vegetatively propagated specialty floral crops. Each plant species was grown at 8-, 10-, 12-, 14-, and 16-h photoperiods. Photoperiods were provided by 8 h of sunlight, then pulling black cloth and providing daylength extension with incandescent bulbs. Data collected included time to flower, flower number, and vegetative characteristics. Evolvulus nuttallianus `Blue Daze', Heliotropium arborescens `Fragrant Delight', and Orthosiphon stamineus `Lavender' were facultative short-day plants with respect to flowering. Time to flower increased as photoperiod increased. Duranta repens `Blue', Verbena hybrid `Tapien Lavender', and Verbena peruviana `Trailing Katie' were facultative long day plants with respect to flowering. Days to visible bud and first open flower decreased as photoperiod increased. Argeranthemum frutescens `Sugar Baby', Scaevola aemula `Fancy Fan Falls', and Portulaca hybrid `Apricot' had increased flower number as photoperiod increased from 8- to 16-h, although time to first flower initiation was not affected. Abutilon hybrid `Apricot', Duranta repens `Blue', Evolvulus nuttallianus `Blue Daze', Lotus berthelotii `Parrot's Beak', Lysimachia nummularia `Aurea Creeping Golden', Rhodanthe anthemoides `Milkyway', and Scaevola aemula `Fancy Fan Falls' had increased vegetative growth as photoperiod increased. All other species studied were day-neutral with regard to flowering and vegetative parameters.

scholarly journals Antitranspirant Treatments of Stock Plants do not alter Growth and Adventitious Rooting of Shoots of ‘Montaigne’ Lilac and White Fringetree

2002 ◽  
Vol 20 (4) ◽  
pp. 240-244
Author(s):  
Susan M. Switras-Meyer ◽  
Jeffrey H. Gillman
Keyword(s):  
Root Length ◽  
Adventitious Rooting ◽  
Shoot Length ◽  
Root Number ◽  
Stock Plant ◽  
Significant Treatment ◽  
Acrylic Emulsion ◽  
Film Forming ◽  
Rooting Of Cuttings ◽  
Plant Treatment

Abstract Antitranspirants were evaluated for their effectiveness as a stock plant treatment to improve adventitious rooting of softwood cuttings of Syringa vulgaris L. ‘Montaigne’ (Montaigne lilac) and Chionanthus virginicus L. (white fringe tree). New shoots of S. vulgaris ‘Montaigne’ and C. virginicus were sprayed with one of two film-forming antitranspirants including Clear Spray® (aqueous acrylic emulsion) and sodium silicate; or Atrazine®, a herbicide that acts as a stomate-regulating antitranspirant. Shoot caliper of antitranspirant-treated lilacs increased more slowly than controls. Thirty days after treatment cuttings were taken from both taxa. All treatments resulted in 80 to 85% rooting of cuttings in lilac after 6 weeks, but cuttings from Clear Spray®-treated plants rooted more quickly. Chionanthus virginicus cuttings treated with Clear Spray® had significantly lower rooting (16%) than cuttings taken from Atrazine® treated plants (50%). In a subsequent experiment, antitranspirant treatment had no significant effect on shoot length or caliper of ‘Montaigne’ lilac. Photosynthetic rate, transpiration rate, and location of cutting on the stock plant were all positively correlated with shoot length, shoot caliper, and cutting diameter. Shoot length and caliper and cutting diameter, however, were all negatively correlated with root number and root length. There were no significant treatment effects on rooting percentage, root number or root length.

scholarly journals Unravelling the Role of Temperature and Photoperiod on Poinsettia Heat Delay

HortScience ◽  
2021 ◽  
pp. 1-7
Author(s):  
Michael Alden ◽  
James E. Faust
Keyword(s):  
Relative Rate ◽  
Flower Initiation ◽  
Euphorbia Pulcherrima ◽  
Large Decrease ◽  
Night Temperature ◽  
Naturally Occurring ◽  
Heat Tolerant ◽  
Delayed Flowering

The effects of day temperature (DT), night temperature (NT), and night length (NL) were evaluated on the flowering responses of heat-tolerant and heat-sensitive poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) cultivars Orion Red and Prestige Red, respectively. Plants were placed under 60 DT × NT × NL treatments that consisted of three DT (20, 24, 28 °C), four NT (16, 20, 24, 28 °C), and five NL (10, 11, 12, 13, 14 hours) for the first 17 days of the experiment. After 17 days, all plants were consolidated to one greenhouse with an inductive environment (14-hour NL, 24 ± 2.0 °C DT and 21.2 ± 1.4 °C NT), and the timing of first color, visible bud, and anthesis were recorded. ‘Orion Red’ reached anthesis 8 to 10 days faster than ‘Prestige Red’ across all NLs; however, in both cultivars, days to anthesis decreased in a sigmoidal pattern as NL increased. The relative rate of progress to anthesis (1/days to anthesis) under a 12-hour NL was approximately half that of plants grown at a 13- or 14-hour NL. At a 12-hour NL, the relative rate of progress to anthesis decreased linearly as DT increased for both cultivars. At 13- to 14-hour NL, DT had relatively little effect on the relative rate of progress to anthesis. Thus, high DT delayed flowering of both heat-tolerant and heat-sensitive cultivars when flower initiation occurred under NL, typical of naturally occurring NLs in September and early October (i.e., 12-hour NL), whereas high DT did not delay flowering for either cultivar under a 14-hour NL, which is typically provided under black cloth systems. In contrast, the flowering responses to NT were quite different for the two cultivars. The heat-tolerant cultivar showed relatively little change in the relative rate of progress to anthesis as NT increased from 16 to 28 °C within each NL treatment; however, the heat-sensitive cultivar displayed a large decrease in the relative rate progress to anthesis as NT increased from 20 to 28 °C within each NL treatment. Although the delayed flowering that occurred at 28 °C and 14-hour NL was significant, the relative rate of progress to anthesis at this treatment was significantly higher than the 28 °C and 12-hour NL treatment. This suggests that artificially shortening NL to 14 hours with a black cloth system does not prevent heat delay of poinsettia, but it allows for more rapid flowering than if flower initiation took place under natural NL (≈12 hours). To summarize, high DT affected flowering when flower initiation took place at 12-hour NL for heat-tolerant and heat-sensitive poinsettia cultivars, whereas high NT uniquely delayed flowering of the heat-sensitive cultivar at NL from 12 to 14 hours.

The effects of photoperiod and light spectrum on stock plant growth and rooting of cuttings ofCotinus coggygria‘Royal Purple’

2005 ◽  
Vol 80 (2) ◽  
pp. 245-253 ◽  
Author(s):  
R.W. F. Cameron ◽  
R. S. Harrison-Murray ◽  
H. L. Judd ◽  
T. R. Marks ◽  
Y.-Y. Ford ◽  
...  
Keyword(s):  
Plant Growth ◽  
Stock Plant ◽  
Light Spectrum ◽  
Rooting Of Cuttings

EFFECTS OF STOCK PLANT ETIOLATION ON THE ROOTING OF SASKATOON BERRY (Amelanchier alnifolia Nutt.) CUTTINGS

1987 ◽  
Vol 67 (1) ◽  
pp. 299-303 ◽  
Author(s):  
S. H. NELSON
Keyword(s):  
Beneficial Effect ◽  
Root Mass ◽  
Stock Plant ◽  
Amelanchier Alnifolia ◽  
Short Period

The etiolation of field-grown, rejuvenated saskatoon berry (Amelanchier alnifolia Nutt.) bushes in 1984 and 1985 proved to be a beneficial aid-to-rooting of softwood cuttings under intermittent mist. The cuttings had to be regreened for a short period of time (6 d) before they were exposed to direct sun in the outdoor intermittent mist propagation bed covered with a clear polyethylene tent. The tedious and time-consuming taping of shoot bases during the regreening period to continue the etiolation process at the base of the cutting proved to be unnecessary with the cultivar Smoky, but gave increased rooting percentage and root mass with the cultivar Pembina on regreened etiolated cuttings in combination with a concentrated auxin. The regreened etiolated treatments produced 95% rooting without auxin with both cultivars. The beneficial effect from the use of a concentrated auxin as a quick dip was more evident on the nonetiolated material, but still increased root mass on the etiolated plant material.Key words: Saskatoon berry, intermittent mist propagation, auxin, softwood cuttings, Amelanchier alnifolia

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