scholarly journals End-of-Day Lighting Effects on Herbaceous Perennials Grown Under Night Interrupted Lighting Outdoors in the Southern United States

2013 ◽  
Vol 31 (1) ◽  
pp. 1-6
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
Stem Elongation ◽  
Growth Index ◽  
Height Growth ◽  
Shoot Length ◽  
Southern United States ◽  
Flower Number ◽  
Herbaceous Perennials ◽  
Natural Photoperiod ◽  
Quality Rating ◽  
Almost All

A study was conducted in 2004 to determine if end-of-day lighting (EOD) alone or in combination with night-interrupted lighting (NIL) could be used to suppress stem elongation of ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’) when grown outdoors under nursery conditions in the southern U.S. without negating the benefits of earlier flowering from NIL. End-of-day lighting, NIL, and the combination of the two treatments accelerated time to flowering of all three cultivars compared to that of plants under a natural photoperiod (NP); however, rudbeckia flowered quicker when exposed to NIL or NIL + EOD than when grown under EOD only. Height of rudbeckia grown under EOD or NIL was greater than that of plants grown under NP, whereas ‘Moonbeam’ coreopsis exposed to EOD, NIL or EOD + NIL were similar in height and taller than plants grown under NP. Height of ‘Early Sunrise’ coreopsis was minimally affected by treatments, except that plants under EOD were shorter than those under EOD + NIL. Growth index, flower number, shoot length and quality rating were similar in almost all cases for plants of the three cultivars when grown under EOD lighting, NIL, or EOD + NIL. These results indicate EOD was ineffective in suppressing height growth and provided no benefit, either alone or in combination with NIL, over NIL alone in the accelerated production of these cultivars outdoors under nursery conditions.

scholarly journals Growth Retardant Use on Herbaceous Perennials Grown Under Night-Interrupted Lighting Outdoors in the Southern United States

2010 ◽  
Vol 28 (2) ◽  
pp. 96-102
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
United States ◽  
Stem Elongation ◽  
Height Growth ◽  
Southern United States ◽  
Growth Retardants ◽  
Flower Bud ◽  
Herbaceous Perennials ◽  
Natural Photoperiod ◽  
One Year ◽  
The One

Abstract A study was conducted in 2002 and 2003 to determine if growth retardants could be used to suppress stem elongation of ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’) when grown outdoors under nursery conditions in the southern United States without negating the benefits of earlier flowering from night-interrupted lighting (NIL). Night-interrupted lighting accelerated flowering of both cultivars without adversely affecting flower and flower bud counts or plant quality. However, plants grown under NIL generally were taller than plants grown under natural photoperiod (NP). When several PGRs [Cutless, B-Nine, B-Nine/Cycocel, Bonzi (2002 only), and Sumagic (2003 only)] were applied to plants under NIL, results varied with PGR type and concentration and year. Height of ‘Moonbeam’ coreopsis was effectively suppressed by 5000 or 7500 ppm B-Nine + 1500 ppm Cycocel in both years of the study and with 40 or 60 ppm Sumagic in the one year it was tested. Higher concentrations of Cutless and B-Nine suppressed height growth in 1 of 2 years, while Bonzi was ineffective. None of the PGR types or concentrations suppressed height growth of ‘Goldsturm’ coneflower to the level of the NP control in 2002. However, in 2003 when an additional application of Cutless and B-Nine were made, and Bonzi was replaced with Sumagic, applications of Cutless, B-Nine, B-Nine/Cycocel, and Sumagic all resulted in heights similar to or less than that of plants under NP with minimal effects on time to flower or flower and flower bud counts.

scholarly journals Night-Interrupted Lighting Accelerates Flowering of Herbaceous Perennials Under Nursery Conditions in the Southern United States

2006 ◽  
Vol 24 (1) ◽  
pp. 23-28
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
United States ◽  
Plant Quality ◽  
Southern United States ◽  
Herbaceous Perennials ◽  
Natural Photoperiod ◽  
Quality Rating ◽  
Second Year ◽  
One Year ◽  
Photoperiod Control

Abstract Night-interrupted lighting (NIL) outdoors in a southern nursery setting was evaluated as a system for accelerated production of herbaceous perennials requiring long days to flower. Treatments were NIL beginning February 1, February 15, March 1, or March 15, and a natural photoperiod control. Compared to plants under the natural photoperiod and depending upon initiation of NIL treatment and year, NIL accelerated and increased flowering of ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) 7 to 36 days and 20 to 244%, ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’) 3 to 20 days and 26 to 64%, ‘Sunray’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Sunray’) 6 to 13 days and 21 to 44%, ‘Autumn Joy’ stonecrop (Sedum x ‘Autumn Joy’) 26 to 57 days and 200 to 300%, and ‘Blue Queen’ salvia (Salvia x superba Stapf ‘Blue Queen’) 7 to 12 days and 56 to 83%. Flowering of ‘Red Beauty’ obedient plant (Physostegia virginiana (L.) Benth. ‘Red Beauty) was accelerated 20 to 54 days; however, inflorescence counts decreased 38 to 46% in one year and was not affected by treatments in the second year. Plants of all cultivars, except ‘Autumn Joy’ sedum and ‘Red Beauty’ obedient plant, were taller when exposed to NIL than when grown under the natural photoperiod, however plant quality rating of all cultivars was as high or higher under NIL.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Coreopsis verticillata ‘Moonbeam’

2007 ◽  
Vol 25 (4) ◽  
pp. 229-233
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Maleic Hydrazide ◽  
Growth Index ◽  
Height Growth ◽  
Growth Retardant ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Quality Ratings ◽  
Quality Rating

Abstract This investigation was conducted to determine the plant growth retardant type, application method, and rate required to produce a marketable greenhouse pot plant of Coreopsis verticillata L. ‘Moonbeam’. Pruned plants in 10 cm (4 in) pots received growth retardant treatments in two experiments consisting of one application of ancymidol or paclobutrazol medium drenches at 0, 2, 4, or 6 ppm; daminozide spray at 0, 2550, 5100, or 7650 ppm; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 ppm; flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 ppm; or maleic hydrazide at 0, 360, 720, 1080, 1440, or 1800 ppm in the first experiment and sprays of daminozide at 0, 2550, 5100, or 7650 ppm; paclobutrazol at 0, 60, or 120 ppm; daminozide/paclobutrazol combinations at 0, 2550/16, 2550/32, 2550/48, or 2550/64 ppm, chloromequat at 0, 767, 1534, or 2301 ppm; or daminozide/chloromequat combinations at 0, 1275/1534, 2550/1534, 3825/1534, or 5100/1534 ppm in the second experiment. In the first experiment, there was a linear decrease in shoot height, growth index, and lateral shoot length with increasing rates of ancymidol and paclobutrazol drenches and flurprimidol sprays while daminozide decreased growth quadratically. There was a linear increase in shoot height and lateral shoot length with increasing rates of maleic hydrazide but no effect on growth index. Only daminozide and maleic hydrazide increased the number of days from treatment to flower with increasing rates. Quality ratings increased with increasing rates of ancymidol, daminozide, and flurprimidol with the highest ratings found at the two highest rates of daminozide and flurprimidol. Paclobutrazol spray did not affect the parameters measured. In the second experiment, chloromequat spray did not affect the parameters measured but when combined with increasing rates of daminozide, linearly decreased shoot height, growth index, and lateral shoot length while increasing the number of days to flower. Daminozide alone resulted in a quadratic change in growth index and lateral shoot length while linearly increasing the number of days to flower but with no effect on quality rating. The higher rates of paclobutrazol than were used in the first experiment decreased shoot height and lateral shoot length with no effect on growth index, the number of days to flower, or quality rating. Overall, the best quality ratings and the most compact plants resulted from spray applications of daminozide at 5100 ppm or 7650 ppm and flurprimidol at 150 ppm or 200 ppm, however flurprimidol is not currently registered for application to greenhouse crops but a newer product, Topflor, has the same active ingredient and greenhouse crop labeling.

scholarly journals Limited Inductive Photoperiod Affects Herbaceous Perennials Grown Under Nursery Conditions in the Southern United States

2008 ◽  
Vol 26 (4) ◽  
pp. 191-196
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
United States ◽  
Plant Height ◽  
Stem Elongation ◽  
Southern United States ◽  
Late Winter ◽  
Herbaceous Perennials ◽  
Quality Ratings ◽  
Natural Photoperiod ◽  
Inductive Photoperiod

Abstract A study was conducted to determine if limited inductive photoperiod (LIP) initiated in late winter could be used to control stem elongation in ‘Goldsturm’ coneflower (Rudbeckia fulgida ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata ‘Moonbeam’), or ‘Early Sunrise’ coreopsis (Coreopsis grandiflora ‘Early Sunrise’), grown outdoors under nursery conditions in the southern United States, without negating the benefits of earlier flowering from night-interrupted lighting (NIL). Treatments were NIL beginning on February 1 and ending on February 15, March 1, March 15, or April 1,2002, plus a natural photoperiod (NP) treatment. The experiment was repeated in 2003 with the inclusion of an additional NIL treatment ending on April 15. LIPs of at least 15 to 30 days, 30 to 45 days, and 30 to 45 days promoted earlier flowering of ‘Early Sunrise’ coreopsis, ‘Moonbeam’ coreopsis, and ‘Goldsturm’ coneflower, respectively. Flower counts and quality ratings of the three cultivars that received LIPs were similar to or higher than those of plants under a NP, except for a reduction in flowering and quality ratings of ‘Goldsturm’ coneflower exposed to LIPs ending on March 1 and March 15, 2002, and on March 1, 2003, and later. LIP effects on plant height were mixed, although there was at least one duration of LIP that resulted in earlier flowering of the three cultivars and plants similar to or shorter than plants under a NP.

scholarly journals Application Timing of Daminizide and Flurprimidol after Shearing Affects Growth and Flowering of Coreopsis verticillata `Moonbeam'

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 603a-603
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Growth Index ◽  
Plant Size ◽  
Height Growth ◽  
Shoot Length ◽  
Growth Retardants ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Application Timing ◽  
Quality Rating ◽  
Response Surface Regression

Vegetative cuttings of Coreopsis verticillata `Moonbeam' were rooted under intermittent mist, pinched, and potted into 10-cm pots in a greenhouse. Plants were sheared to 6.5 cm above the pot rim 2 weeks after potting and given foliar sprays of daminozide at 0, 2550, 5100, or 7650 mg·L-1 or flurprimidol at 0, 50, 100, or 150 mg·L-1. Night-break lighting to provide long photoperiods was started the day of shearing. Growth retardants were applied at 0, 3, 6, 9, 12, or 15 days after shearing. Daminozide reduced shoot height, growth index, and lateral shoot length compared to the control by 69.3%, 69.2%, and 70.0%, respectively, while increasing quality rating by 67.3% and time to flower by 8 days at 5100 and 7650 mg·L-1. Response surface regression predicted that minimum plant size and maximum quality rating occurred when growth retardants were applied 5.7 to 8.3 days after shearing. Application timing had no effect on responses to flurprimidol. Shoot height, growth index, and lateral shoot length decreased quadratically with increasing rate while quality rating only improved compared to control. Flurprimidol did not cause a flowering delay.

scholarly journals Characterization of Postharvest Disorders and the Effect of Shipping on Shelf Life of 22 Vegetative Annual Cultivars

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 835D-836
Author(s):  
Shannon E. Beach* ◽  
Terri W. Starman
Keyword(s):  
Shelf Life ◽  
Petunia Hybrida ◽  
Stem Elongation ◽  
Flower Number ◽  
Leaf Chlorosis ◽  
Growth Room ◽  
Greenhouse Culture ◽  
Quality Rating ◽  
Greenhouse Growers

Vegetative annuals are increasing in popularity among greenhouse growers and consumers but little is known about their postharvest shelf life. Twenty-two cultivars from ten species of vegetative annuals were grown to marketability with optimum greenhouse culture. Plants were then subjected to one of three shipping durations (0, 1, or 2 days) in simulated shipping i.e., a growth chamber at 26.7 ± 0.3 °C, 0 μmol·m-2·s-1, and 50% relative humidity. The plants were then moved to simulated postharvest environment i.e., growth room at 21.1 ± 1.3 °C and 6 μmol·m-2·s-1 to evaluate shelf life. Flower number and plant quality rating were measured weekly in addition to observations of plant appearances. Some of the postharvest disorders noted on several species and cultivars were stem die back, leaf chlorosis, stem elongation, bud abortion, flower drop, and flower fading. The majority of the cultivars maintained their quality one-week postharvest although flower drop was common. After the first week of shelf life, decline in vegetative and reproductive tissues were noted in most plants. Cultivars from nine species: Argyranthemum frutescens (L.) Sch. Bip, Bracteantha bracteata (Vent.) Anderb. & Haegi, Calibrachoa hybrid Lave Lex, Diascia ×hybrida, Lantana camara L., Nemesia ×hybrida, Petunia ×hybrida, Sutera hybrida, and Sutera cordata showed decreased flower number and/or quality rating due to shipping duration, with increased shipping duration causing accelerated postharvest disorders. The only species unaffected by shipping duration was Angelonia angustifolia Benth.

scholarly journals Accelerated Flowering of Herbaceous Perennials Under Nursery Conditions in the Southern United States

2001 ◽  
Vol 19 (3) ◽  
pp. 140-144
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
United States ◽  
Plant Height ◽  
Plant Quality ◽  
Southern United States ◽  
Late Winter ◽  
Flower Bud ◽  
Herbaceous Perennials ◽  
Natural Photoperiod

Abstract A study was conducted to determine the effects of night-interrupted (NI) lighting initiated at different times in late winter on several herbaceous perennials produced outdoors in a southern nursery setting. Treatments were NI lighting beginning February 1, February 15, March 1, March 15, and a natural photoperiod. NI lighting accelerated flowering in ‘Goldsturm’ coneflower (Rudbeckia fulgida Ait. ‘Goldsturm’) 26–46 days in 1999 and 51–75 days in 2000, and in ‘Coronation Gold’ yarrow (Achillea x ‘Coronation Gold’) 2–9 days in 1999 and 2–11 days in 2000. Flower and flower bud counts increased 82–100% in ‘Coronation Gold’ achillea in 1999, 44–51% in ‘Butterfly Blue’ scabious (Scabiosa columbaria L. ‘Butterfly Blue’) and 100–151% in ‘Alaska’ shasta daisy (Leucanthemum x superbum Bergmans ex. J. Ingram ‘Alaska’) compared to counts of plants under natural photoperiod. With few exceptions, plant height increased under all NI lighting treatments, but in only ‘Goldsturm’ coneflower did it reduce plant quality. Clump verbena (Verbena canadensis L.) was minimally affected by NI lighting, and speedwell (Veronica spicata L. ‘Sunny Border Blue’) was not affected at all.

scholarly journals Bulking Duration Affects Growth and Flowering of Herbaceous Perennials Grown Under Nursery Conditions and Forced Into Flower Under Night-Interrupted Lighting Outdoors in the Southern United States

2014 ◽  
Vol 32 (1) ◽  
pp. 19-26
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
United States ◽  
Plant Height ◽  
Similar Pattern ◽  
Southern United States ◽  
Flower Bud ◽  
Start Date ◽  
Herbaceous Perennials ◽  
Flower Plant ◽  
Natural Photoperiod ◽  
Start Dates

The effects of bulking duration on growth and flowering of ‘Goldsturm’ black-eyed Susan (Rudbeckia fulgida Ait. ‘Goldsturm’) and ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) forced into flower under nursery conditions were evaluated as part of a system for the accelerated production of herbaceous perennials requiring long days to flower. Bulking duration treatments were established by a factorialization of potting date (September 24, October 13, December 2, and December 14, 2009) and night-interrupted lighting (NIL) start date (February 1, February 22, and March 15, 2010). Leaf counts of black-eyed Susan at the beginning of NIL increased linearly with progressively longer bulking durations based on potting date and NIL start date, although the effect was more pronounced when compared across potting dates. Based on leaf counts, black-eyed Susan potted in December were still in the juvenile phase when NIL was begun on February 1, 2010. Stem counts of black-eyed Susan at first flower followed a similar pattern as leaf counts. Black-eyed Susan given NIL flowered 40 to 59 days before plants under natural photoperiod (NP). Flower plus flower bud counts of black-eyed Susan at first flower increased linearly with increasing bulking duration based on potting date: by 325, 268, and 243% when NIL was begun on February 1, February 22, and March 15, respectively. Flower counts also increased linearly approximately 46% with increasing bulking duration based on NIL start dates, but only when plants were potted in December. At first flower, plant height of black-eyed Susan given NIL increased linearly as bulking duration increased based on potting date, but did not differ when trended across the NIL start dates. Days to flower of coreopsis decreased with increasing bulking duration, while stem counts increased with bulking duration, and the number of marketable plants was greater when plants were repotted on the three earliest dates compared to those bulked the shortest duration. Effects of bulking duration on flower plus flower bud counts and height of coreopsis were inconsistent.

scholarly journals Shasta Daisy Cultivars Respond Differently to Photoperiod and Vernalization

2007 ◽  
Vol 25 (2) ◽  
pp. 100-104
Author(s):  
J.T. Coleman ◽  
J.R. Kessler ◽  
G.J. Keever ◽  
J.L. Sibley
Keyword(s):  
Growth Index ◽  
Plant Size ◽  
Height Growth ◽  
Practical Application ◽  
Shoot Height ◽  
Shoot Number ◽  
Quality Rating ◽  
Short Days

Abstract Inconsistencies have been reported in the role of vernalization and photoperiod on growth and flowering of Leucanthemum x superbum Bergmans ex J. Ingram cultivars. Five cultivars were used to determine the effects of vernalization and photoperiod on days to flower, shoot height, growth index, flower shoot number, and quality rating. Plants received 0, 3, 6, 9, or 12 weeks of vernalization time (VER) at 4.4C (40F) and afterward were placed under either natural short days (SD) or night-interrupted lighting (NIL) in a greenhouse. ‘Becky’ showed an obligate requirement for NIL to flower with 100% of plants flowering under NIL and 0% of plants flowering under SD regardless of VER. Vernalization for 6 weeks before NIL increased shoot height, growth index, flower shoot number, and quality rating but the fewest days to flower occurred after 12 weeks of VER. ‘Silver Princess’, ‘Snow Cap’, ‘Snow Lady’, and ‘Summer Snowball’ showed a facultative requirement for NIL to flower. Plants under NIL flowered earlier, were larger, had more flower shoots, and had a higher overall quality rating than plants under SD. Shoot height and growth index were highest under NIL after 3 and 6 weeks of VER, flower shoot number was highest after 3 to 9 weeks of VER, but days to flower was least after 12 weeks of VER. Therefore, NIL after 3 or 6 weeks of VER would maximize plant size and quality for practical application in the cultivars studied but result in more DTF when compared to 12 weeks of VER.

Thermodormancy in Seedlings of Eucalyptus obliqua L'herit

1976 ◽  
Vol 3 (2) ◽  
pp. 269 ◽  
Author(s):  
TJ Blake
Keyword(s):  
High Temperature ◽  
Respiration Rate ◽  
Respiratory Quotient ◽  
Stem Elongation ◽  
Temperature Treatment ◽  
Height Growth ◽  
High Temperature Treatment ◽  
Total Polyphenols ◽  
Terminal Buds

High (30°C) day and night temperatures reduced mainstem elongation in E. obliqua seedlings resulting in a temporary quiescence in height growth after 8 days of high temperature treatment; rapid stem elongation did not recommence when seedlings were returned to conditions usually favourable to growth. Associated with the onset of quiescence were: an increase in the respiratory quotient and a decrease in the respiration rate of upper terminal buds; an accumulation of inhibitory substances; and an increase in total polyphenols in the stem.

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