scholarly journals Photoperiod, Juvenility, and High Intensity Lighting Affect Flowering and Cut Stem Qualities of Campanula and Lupinus

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1192-1196 ◽  
Author(s):  
Todd J. Cavins ◽  
John M. Dole
Keyword(s):  
High Intensity ◽  
Stem Diameter ◽  
Stem Length ◽  
Leaf Stage ◽  
Long Day ◽  
Supplemental Lighting ◽  
Long Day Plants

Campanula medium L. `Champion Blue' and `Champion Pink' and Lupinus hartwegii Lindl. `Bright Gems' were grown in 8- or 16-h initial photoperiods, transplanted when 2-3, 5-6, or 8-9 true leaves developed, and placed under 8-, 12-, or 16-h final photoperiods. The lowest flowering percentage for `Champion Blue' (<1%) and `Champion Pink' (16%) resulted from plants grown in the 8-h photoperiod continuously. One hundred percent flowering occurred when Campanula were grown in the 16-h final photoperiod, indicating that `Champion Blue' and `Champion Pink' are long-day plants. Plants grown initially in the 8-h and finished in the 16-h photoperiod had the longest stems. Stem diameter was generally thickest for plants grown in the 8-h compared with the 16-h initial photoperiod. However, the 8-h initial photoperiod delayed anthesis compared with the 16-h initial photoperiod. `Champion Blue' and `Champion Pink' plants transplanted at the 2-3 leaf stage from the 16 hour initial to the 8-h final photoperiod had flowering percentages of 64% and 63%, respectively; however, when transplanted at the 8-9 leaf stage, plants were fully mature and 100% flowering occurred indicating that all plants were capable of flowering. In year 2, plants receiving high intensity discharge (HID) supplemental lighting during the 16-h initial photoperiod reached anthesis in 11 fewer days compared with plants not receiving HID supplemental lighting. High profits were obtained from Campanula grown in the 8-h initial photoperiod and transferred at 5-6 true leaves into the 16-h final photoperiod. Lupinus hartwegii plants had a high flowering percentage (96% to 100%) regardless of photoperiod or transplant stage. The 16-h final photoperiod decreased days to anthesis compared with the 8- or 12-h final photoperiod indicating that L. hartwegii is a facultative long-day plant. Increasing length of final photoperiod from 8- to 16-h increased stem length. Juvenility was not evident for Lupinus in this study. In year 2, Lupinus cut stems were generally longer and thicker when given HID supplemental lighting, especially when grown in the 8- or 12-h final photoperiod. Supplemental lighting also reduced days to anthesis. Highest profits were generally produced from Lupinus plants grown with supplemental HID lighting (during the initial photoperiod) until 8-9 true leaves had developed.

Variability in photoperiod and the inhibition of flowering in a high latitude population of Saxifraga rivularis

1981 ◽  
Vol 59 (3) ◽  
pp. 388-391 ◽  
Author(s):  
J. A. Teeri ◽  
S. J. Tonsor
Keyword(s):  
High Latitude ◽  
High Intensity ◽  
Dark Period ◽  
Controlled Environment ◽  
Photoperiodic Control ◽  
Incandescent Light ◽  
Devon Island ◽  
Low Intensity ◽  
Long Day ◽  
Long Day Plants

A population of Saxifraga rivularis L. collected at Truelove Lowland, Devon Island, N.W.T., Canada (75°41′ N) exhibits a photoperiodic control of flowering in controlled environment chambers. The plants respond in a manner typical of long-day plants with flowering inhibited by either a 6-h daily dark period, or by a 6-h daily low intensity irradiance regime of incandescent light. The inhibition of flowering by 6 h day−1 of incandescent light does not occur if the incandescent light is given in twelve 0.5-h doses, each followed by 1 h of red-rich high intensity irradiance.

Vernalization Accelerates Flowering of Lysimachia clethroides Duby

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508b-508
Author(s):  
Pamela M. Lewis ◽  
Alan M. Armitage ◽  
Jim M. Garner
Keyword(s):  
Stem Diameter ◽  
Stem Length ◽  
Cut Flower ◽  
Bud Formation ◽  
Flower Production ◽  
Sphagnum Peat ◽  
Potting Media ◽  
Lysimachia Clethroides ◽  
Shoot Emergence

The effect of vernalization method and duration on off-season cut flower production of Lysimachia clethroides Duby was examined. Rhizomes harvested in October were cooled for 0, 4, 6, 8, 10 or 12 weeks at 4 ± 1 °C in crates with unmilled sphagnum peat or in 3.75-L pots with potting media prior to forcing in a warm greenhouse. After 6 or more weeks of cooling, shoots emerged from crate-cooled rhizomes in higher percentages than from pot-cooled rhizomes. However, only the duration of cooling, not the method, affected the rate of shoot emergence, visible bud formation and anthesis of the first bud in the raceme. As cooling increased from 0 to 12 weeks, the greenhouse days required for shoot emergence, visible bud formation and anthesis decreased linearly. The number of flowering flushes and flowering stems varied quadratically with cooling duration, and the highest yields occurred when rhizomes received between 4 and 10 weeks of cooling. As the number of successive flowering flushes increased, the stem length increased linearly while the stem diameter decreased linearly. High numbers of flowers were produced rapidly after 10 weeks of cooling.

Production of the Australian native daisies (Helipterum roseum and Helichrysum bracteatum) for the cut flower market

1989 ◽  
Vol 29 (3) ◽  
pp. 445 ◽  
Author(s):  
KV Sharman ◽  
M Sedgley ◽  
D Aspinall
Keyword(s):  
Stem Length ◽  
Floral Initiation ◽  
Cut Flower ◽  
Planting Time ◽  
Flower Production ◽  
Long Day ◽  
Spring Peak ◽  
Fresh Cut ◽  
Helichrysum Bracteatum ◽  
Optimum Production

Cut flower production of 2 Australian native daisies, Helipterum roseum and Helichrysum bracteatum, was investigated in the glasshouse and outdoors at 4 planting times. Both species exhibited a long day response with floral initiation occurring in any photoperiod but with peak production following longer days. Peaks in bloom production occurred during the spring and summer regardless of planting time. Floral abnormalities were observed in Helipterum roseum in all environments and planting times with the exception of the outdoor winter planting. There was a tendency for inflorescence diameter of both species and stem length of Helipterum roseum to decline with time from anthesis of the apical inflorescence. Optimum production of top quality blooms of Helipterum roseum extended from October to January following planting between autumn and spring. Peak production of Helichrysum bracteatum between December and March can be expected following planting during winter and spring. It may be possible to extend these seasons by weekly planting from autumn to spring. In addition, the imposition of extended photoperiod or night break treatments following summer or autumn planting may fulfil the photoperiod requirements of the plants and stimulate increased production between March and November. It is proposed that both species be considered for the fresh cut flower market, with Helipterum roseum marketed as single stems and Helichrysum bracteatum as sprays.

GREENHOUSE ROSE SPACING UNDER HIGH INTENSITY SUPPLEMENTAL LIGHTING

1977 ◽  
Vol 57 (1) ◽  
pp. 101-105 ◽  
Author(s):  
M. J. TSUJITA
Keyword(s):  
High Pressure ◽  
High Intensity ◽  
Rosa Hybrida ◽  
Continuous Illumination ◽  
Plant Spacing ◽  
Cut Flower ◽  
Fresh Weight ◽  
Flower Number ◽  
Plant Stem ◽  
Supplemental Lighting

Four plant spacings of 0.07, 0.09, 0.12 and 0.18 m2/plant were evaluated for Rosa hybrida cv. Forever Yours cultured in a commercial greenhouse equipped with 400 W high pressure sodium lamps emitting 22 W/m2 of supplemental light/24 h or 2,500 lx/24 h continuous illumination. Cut flower yields of four harvests for 11 May 1975, 25 Dec. 1975, 14 Feb. 1976 and 9 May 1976 were similar among the four plant spacing treatments from the first harvest. Cut flower number per plant increased significantly with each increment in spacing per plant. Stem lengths were longer in the 0.12 and 0.18 m2/plant spacings for December and February harvests. Flower fresh weight was greater in the 0.18 m2/plant spacing for December, similar to the 0.12 m2/plant spacing for the February harvest but larger than the.07 and.09 m2/plant spacings. These results indicate that the yield of Forever Yours roses spaced at 0.12–0.18 m2/plant and cultured under high intensity supplemental lights can be maintained at a productive level comparable to that at the standard spacing of.09 m2/plant.

Possible roles for ethylene and gibberellin in the phenotypic plasticity of an alpine population of Stellaria longipes

2006 ◽  
Vol 84 (7) ◽  
pp. 1101-1109 ◽  
Author(s):  
Leonid V. Kurepin ◽  
Lisa Mancell ◽  
David M. Reid ◽  
Richard P. Pharis ◽  
C.C. Chinnappa
Keyword(s):  
Leaf Size ◽  
The Other ◽  
Stem Length ◽  
Endogenous Gibberellin ◽  
Ethylene Evolution ◽  
Stellaria Longipes ◽  
Enhanced Sensitivity ◽  
Long Day ◽  
Alpine Population ◽  
Endogenous Ethylene

Four phenotypically different genotypes from an alpine population of Stellaria longipes Goldie s.l. (Caryophyllaceae) were collected from neighbouring sites at the top of the Plateau Mountain in southeastern Alberta, Canada, to examine a possible hormonal basis for their differences in stem length, leaf size, and flowering characteristics. All four genotypes had a dwarf shoot phenotype, compared with the low-elevation ecotype. Among the four genotypes, PMI-D was the tallest and had the largest leaves and flowers as well as more flowers per plant. PMI-D also maintained the flowering state, upon repropagation, without low temperature, short-day vernalization. Under controlled long-day warm conditions, the PMI-D genotype had a higher rate of ethylene evolution, but contained levels of endogenous gibberellin A1 that were similar to the other three (smaller) alpine genotypes. PMI-D was more sensitive to exogenously applied ethylene and growth-active gibberellins than other alpine genotypes. In contrast, the other three genotypes were smaller, had fewer (and smaller) flowers, and exhibited low ethylene evolution and a reduced sensitivity to applied ethylene and growth-active gibberellins. Speculatively, this behaviour may indicate an adaptation within this unique population of “dwarf” phenotypes that involves enhanced sensitivity to endogenous ethylene and gibberellins.

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