scholarly journals Effects of Ethephon on Stock Plant Management of Coreopsis verticillata, Dianthus caryophyllus, and Veronica longifolia

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1616-1621 ◽  
Author(s):  
Janelle E. Glady ◽  
N. Suzanne Lang ◽  
Erik S. Runkle
Keyword(s):  
Dianthus Caryophyllus ◽  
Plant Management ◽  
Internode Elongation ◽  
Perennial Species ◽  
Stock Plant ◽  
Long Day ◽  
Leaf Necrosis ◽  
Vegetative Cuttings ◽  
Herbaceous Perennial ◽  
Short Days

Some day-neutral herbaceous perennial species can be difficult to manage as vegetative stock plants because they initiate floral buds under most environmental conditions. Although flowering of many long-day plants can be inhibited by maintaining plants under short days, extension growth is often suppressed, which makes cuttings difficult to harvest. Ethephon (2-chloroethylphosphonic acid) is an ethylene-releasing chemical used to abort flowers, inhibit internode elongation, and promote branching of floriculture crops. The objective of this research was to determine whether ethephon is effective at maintaining vegetative growth and increasing the number of cuttings harvested for three popular perennial species that are difficult to maintain as vegetative plants. Spray applications of ethephon were applied for 10 weeks biweekly (every 2 weeks) or weekly at 0, 400, 600, or 800 mg·L−1. Biweekly applications at 600 mg·L−1 or weekly applications at 400 mg·L−1 increased branching and the number of vegetative cuttings in Coreopsis verticillata L. ‘Moonbeam’ and Veronica longifolia L. ‘Sunny Border Blue’, respectively. Ethephon application increased branching in Dianthus caryophyllus L. ‘Cinnamon Red Hots’, inhibited leaf expansion and stem extension, but did not abort flowers, and induced marginal leaf necrosis at all concentrations tested. Therefore, ethephon application has potential to maintain vegetative stock plants of C. verticillata ‘Moonbeam’ and V. longifolia ‘Sunny Border Blue’ but not D. caryophyllus ‘Cinnamon Red Hots’.

scholarly journals The Response of Long-day Herbaceous Perennials to a Night-interruption at Low Night Temperatures

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 484D-484
Author(s):  
Alison Frane ◽  
Royal Heins ◽  
Art Cameron ◽  
William Carlson
Keyword(s):  
Low Temperature ◽  
Early Spring ◽  
Perennial Species ◽  
Treatment Results ◽  
Flower Bud ◽  
Herbaceous Perennials ◽  
Long Day ◽  
Node Count ◽  
Herbaceous Perennial ◽  
Short Days

A 4-hr night interruption (NI) is an effective way to promote flowering in many long-day herbaceous perennials. Some perennials are grown outdoors in the early spring and often are exposed to low night temperatures. Long days delivered by NI lighting ineffectively promote flowering under low-temperature conditions in some long-day species. The objective of this experiment was to determine the effectiveness of NI long-day lighting treatments delivered at different night temperatures in promoting flowering of several herbaceous perennials. Ten herbaceous perennial species were grown under natural short days augmented with a 4-hr NI. Night temperatures were 2.5, 5, 10, 15, 20, and 25°C with day temperature of 25°C for all treatments. Plants were transferred to 9-hr days at a constant 20°C after 7 weeks of treatment. Results on flowering percentage, date of visible bud and flowering, node count, flower bud count, and plant height at flowering will be presented.

Vegetative Activity of the Main Stem Terminal Bud Under Photoperiod and Flower Removal Treatments in Soybean

1988 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
SV Caffaro ◽  
F Nakayama
Keyword(s):  
Main Stem ◽  
Internode Elongation ◽  
Apical Bud ◽  
Apical Buds ◽  
Long Day ◽  
Flower Abortion ◽  
Terminal Bud ◽  
Photoperiodic Treatment ◽  
The Moment ◽  
Short Days

Effects of photoperiod and flower removal on vegetative activity of the main stem apical bud were examined for an indeterminate ('Williams') and a determinate ('Bragg') soybean cultivar. Plants grew under long day conditions until the V2 stage. Then, they were subjected to three photoperiodic treatments: (1) short days of 9 h of solar radiation during all the experiment (SD); (2) 10 short days followed by long days until the end of the experiment (SD + LD); and (3) long days during all the experiment (LD). From the moment anthesis was reached, half of the plants of each photoperiodic treatment were periodically deflowered. Flower removal induced an additional but limited vegetative growth of the main stem apex, due to the elongation of the youngest internodes. This effect was only seen under SD because long day applications (SD+LD and LD) induced a high flower abortion. On the contrary, long days stimulated internode elongation, leaf expansion and, under LD, delayed anthesis which resulted in enhanced vegetative activity of apical buds and a greater production of nodes and branches. Thus, a close but inverse relation was observed between flower induction and vegetative structure differentiation by apical buds. As in Bragg, Williams may stop vegetative activity of buds by their simple transition to a terminal raceme hence, only posterior differentiated internode elongation will be either limited or stimulated depending on SD or LD conditions, respectively.

scholarly journals 391 THE INFLUENCE OF COLD DURING SEEDLING STAGE AND PHOTOPERIOD ON FORCING PERENNIALS FOR POT PLANTS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 487b-487
Author(s):  
Allan M. Armitage ◽  
Paul Thomas
Keyword(s):  
Plant Height ◽  
Early Spring ◽  
Seedling Stage ◽  
Internode Elongation ◽  
Perennial Species ◽  
Photoperiodic Treatment ◽  
Short Days ◽  
Pot Plants

The influence of cooling, photoperiod and chemical branching on early spring flowering of perennial species was studied. Cooling was provided while plants were in plugs (128 plugs per tray) and dikegulac-sodium, a compound found to induce breaks in other species, was applied prior to, during and after cooling. Plants were cooled in insulated lighted coolers for 4, 8 or 12 weeks at 4C, and brought to a greenhouse with night temperatures between 8-12C. Long and short days were provided in the greenhouse after plants came out of the coolers. Little response to dikegulac occurred, however, Campanula, Sedum, Leontopodium, Catananche, Aubrietia, Arabis, Gypsophila, Anchusa and Aquilegia responded to cooling and photoperiodic treatment. Flowering and vegetative characteristics such as internode elongation and plant height responded to photoperiod and cooling but not all genera responded similarly. Anchusa, Campanula, Aquilegia and Gypsophila flowered significantly earlier under LD compared to SD. Twelve weeks of cooling resulted in flowering of all genera, however, some genera were equally responsive to shorter cooling times.

Cold Treatments Alter the Photoperiodic Flowering Response of Some Herbaceous Perennial Species

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508c-508
Author(s):  
Erik S. Runkle ◽  
Royal D. Heins ◽  
Arthur C. Cameron ◽  
William H. Carlson
Keyword(s):  
Cold Treatment ◽  
Cold Period ◽  
Photoperiodic Induction ◽  
Perennial Species ◽  
Additional Species ◽  
Flowering Response ◽  
Herbaceous Perennials ◽  
Photoperiodic Flowering ◽  
Herbaceous Perennial ◽  
Short Days

Many species of herbaceous perennials either require a cold treatment for flowering or exhibit enhanced and more desirable flowering characteristics following a cold period. For some species, the photoperiodic induction of flowering can change following cold treatments, the parameters generally becoming less strict as plants receive longer durations of cold until a saturation duration is reached. To quantify the minimum and saturation durations of cold for flowering under short days (SD) and long days (LD), five species were selected and cooled for 0, 3, 6, 9, 12, or 15 weeks at 5 °C, then forced at 20 °C under 9-h photoperiods without (SD) or with a 4-h night interruption (LD). The effects of cold and photoperiod on flowering varied by species. For example, under SD, 0%, 80%, or 100% of Leucanthemum xsuperbum `Snowcap' flowered after 0, 3, or ≥6 weeks at 5 °C, respectively, and time to flower decreased from 103 to 57 days as the duration of cold increased from 3 to 12 weeks. `Snowcap' cooled for ≥3 weeks, then forced under LD, flowered completely in 45 to 55 days. Flowering percentage of Lavandula angustifolia `Hidcote' reached 100 under LD or SD only when plants were cooled for ≥6 or 15 weeks, respectively. Under LD, flowering percentage of Astilbe chinensis pumila progressively increased from 0 to 100 as cold treatment increased from 0 to 15 weeks; flowering percentage under SD was low regardless of cold treatment. Additional species and flowering characteristics will be discussed.

scholarly journals Effects of Cold and Photoperiod on Flowering of Several Herbaceous Perennial Species

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 581b-581
Author(s):  
Erik S. Runkle ◽  
Royal D. Heins ◽  
Arthur C. Cameron ◽  
William H. Carlson
Keyword(s):  
Cold Treatment ◽  
Continuous Light ◽  
Flower Initiation ◽  
Perennial Species ◽  
Cold Response ◽  
Long Day ◽  
Before And After ◽  
Cold Requirement ◽  
Incandescent Lamps ◽  
Herbaceous Perennial

Thirty herbaceous perennial species were treated at 5°C for 0 or 15 weeks. Critical photoperiods for flower initiation and development with and without a cold treatment were determined. Photoperiods were 10, 12, 13, 14, 16, or 24 hours of continuous light or 9 hours plus a 4-hour night interruption. Continuous photo-periodic treatments consisted of 9-hour natural days extended with light from incandescent lamps. Species were categorized into nine response types based on the effects of cold and photoperiod on flowering. Plants had three flowering responses to cold treatment: obligate, facultative, or none. The perennials were obligate long-day, facultative long-day, or day-neutral plants. For example, Campanula carpatica `Blue Clips' had no response to cold and was an obligate long-day plant requiring photoperiods of 16 hours or longer or night interruption for flowering. Rudbeckia fulgida `Goldsturm' had a facultative response to cold and required photoperiods of 14 hours or longer or night interruption for flowering. Veronica longifolia `Sunny Border Blue' had an obligate cold requirement and was day-neutral. Some species responded differently to photoperiod before and after cold. Leucanthemum ×superbum `Snow Cap' flowered as an obligate long-day plant without cold and as a facultative long-day plant after cold. Response categories are discussed.

scholarly journals Influence of Daylength Delivery on Flowering in Several Herbaceous Perennial Species

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 861F-861
Author(s):  
Cheryl Hamaker ◽  
William H. Carlson ◽  
Royal D. Heins ◽  
Arthur C. Cameron
Keyword(s):  
Continuous Light ◽  
Flower Induction ◽  
Perennial Species ◽  
Herbaceous Perennials ◽  
Short Day ◽  
Long Day ◽  
Herbaceous Perennial ◽  
Campanula Carpatica

To determine the most effective lighting strategies for flower induction of long-day (LD) plants, 10 species of herbaceous perennials were chilled at 5C for 0 or 12 weeks and then forced at 20C under the following photoperiods: short day, 4-h night interruption (4-h NI), 7-h night interruption (7-h NI), 7-h day extension, 7-h predawn (7-h PD), and 24-h continuous light (24-h). All treatments consisted of a 9-h photoperiod of sunlight supplemented with 90 μmol·m–2 from HPS lamps. LD treatments were delivered by incandescent lights and induced flowering in obligate LD plants. Rate of flowering, height, and bud number at first flower varied among species and LD treatments. Although flowering was accelerated under 24-h and 7-h NI for most species, it was delayed under 24 h for Coreopsis verticillata `Moonbeam' and Campanula carpatica. For unchilled plants of most species, flowering was delayed under 7-h PD compared to other LD treatments. Chilling decreased time to flower and reduced differences between LD treatments. Coreopsis `Moonbeam' and C. Ianceolata `Early Sunrise' were shorter when grown under 4-h NI.

scholarly journals Effect of Stock Plant Photoperiod and Temperature on Cutting Production and Rooting of Herbaceous Perennials

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 501E-501
Author(s):  
Paul Koreman ◽  
Art Cameron ◽  
Royal Heins ◽  
William Carlson
Keyword(s):  
Stock Plant ◽  
Herbaceous Perennials ◽  
Long Day ◽  
Phlox Paniculata ◽  
Short Days ◽  
Cutting Production

Previous research has shown that the photoperiod under which stock plants are grown has a significant effect on cutting production and rooting of several species of herbaceous perennials. Long-day (LD) treatment of stock plants promoted cutting production of certain LD perennials but reduced rooting. Cuttings from plants grown under short days rooted readily but few were produced. Stock plants were exposed to alternating photoperiods to determine if this treatment would yield many cuttings with high rooting potential. Coreopsis verticillata `Moonbeam' and Phlox paniculata `Eva Cullum' stock plants were given 4 weeks of 4-h night interruption (NI), while Sedum `Autumn Joy' stock plants were grown under 14-h days. After 4 weeks plants were given 0, 2, or 4 weeks of 10-h days. Cuttings were harvested and propagated under mist and three different photoperiods (10-h, 14-h, NI) for 4 weeks, after which rooting percentage and the number and length of roots produced by each cutting were measured. The results will be presented.

scholarly journals FLORAL INITIATION IN THE LONG-DAY PLANT Rudbeckia hirta

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 719A-719
Author(s):  
Richard L. Harkess ◽  
Robert E. Lyons
Keyword(s):  
Methyl Green ◽  
Floral Initiation ◽  
Serial Sections ◽  
Sodium Cacodylate ◽  
Rudbeckia Hirta ◽  
Long Day ◽  
Cacodylate Buffer ◽  
Ethanol Series ◽  
Inductive Photoperiod ◽  
Short Days

A study was undertaken to determine the rate of floral initiation in Rudbeckia hirta. R. hirta plants were grown to maturity, 14-16 leaves, under short days (SD). Paired controls were established by placing half of the plants under long days (LD) with the remainder left under SD. Beginning at the start of LD (day 0), five plants were harvested daily from each photoperiod group for twenty days. Harvested meristems were fixed in 2% paraformaldehyde - 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.0) for 24 hrs, dehydrated in an ethanol series, embedded in paraffin and sectioned at 8 μm. Serial sections were stained with Methyl-green Pyronin, with adjacent sections treated with RNase for nucleic acid comparison. All events of floral initiation were identified, The results of limited inductive photoperiod indicate that 16-18 LD were required for flowering.

Flowering of Stylosanthes guianensis in controlled temperatures under natural photoperiod

1984 ◽  
Vol 35 (2) ◽  
pp. 219 ◽  
Author(s):  
RL Ison ◽  
LR Humphreys
Keyword(s):  
Floral Initiation ◽  
Minimum Duration ◽  
Stylosanthes Guianensis ◽  
Short Day ◽  
Long Day ◽  
Natural Photoperiod ◽  
Low Levels ◽  
Short Days

Seedlings of Stylosanthes guianensis var. guianensis cv. Cook and cv. Endeavour were grown in naturally lit glasshouses at Brisbane (lat. 27� 30' S.) at 35/30, 30/25 and 25/20�C (day/night), and were sown so as to emerge at 18-day intervals from 18 January to 11 June. Cook behaved as a long day-short day plant, with seedlings emerging after 5 February flowering incompletely or remaining vegetative until the experiment was terminated in mid-October. In the 25/20�C regimen flowering was incomplete in Cook; in Endeavour flowering was delayed but a conventional short-day response was observed. At 35/30�C Endeavour flowering was inhibited in the shortest days of mid-winter, suggesting a stenophotoperiodic response, but short days were confounded with low levels of irradiance. Minimum duration of the phase from emergence to floral initiation was c. 66-70 days in Cook and c. 40-45 days in Endeavour; the duration of the phase floral initiation to flower appearance was linearly and negatively related to temperature.

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