Spectral Effects of Supplemental Greenhouse Radiation on Growth and Flowering of Annual Bedding Plants and Vegetable Transplants

in HortScience

Supplemental radiation (SR), traditionally provided by high-pressure sodium (HPS) lamps, is recommended for greenhouse production of seedlings during radiation-limiting conditions. Light-emitting diodes (LEDs) have emerged as an appealing alternative to HPS lamps primarily because they can provide SR at improved energy efficiencies, they have longer fixture lifetimes, and the radiation spectrum can be tailored to potentially manipulate plant morphology by targeting radiation absorption of specific photoreceptors. We grew seedlings of three annual bedding plants and two vegetable transplants in greenhouses at 20 °C under a 16-h photoperiod under six SR treatments: five that delivered a photosynthetic photon flux density (PPFD) of 90 μmol·m−2·s–1 from HPS lamps (HPS90) or LEDs [four treatments composed of blue (B; 400–500 nm), red (R; 600–700 nm), far red (FR; 700–800 nm), and/or white LEDs] and one that delivered 10 μmol·m−2·s–1 from HPS (HPS10) lamps as a control with matching photoperiod. The LED treatments, defined by the percentages of B, green (G; 500–600 nm), and R radiation, were B10R90, B45R55, B10G5R85, and B12G20R68 + FR (FR at 12 μmol·m−2·s–1). At transplant, leaf area and seedling height were similar among 90 μmol·m−2·s–1 treatments in all species except snapdragon (Antirrhinum majus), in which seedlings grown under B12G20R68 + FR had 62% greater leaf area than those grown under B45R55 and were 47%, 18%, 38%, and 62% taller than those grown under HPS90, B10R90, B10G5R85, and B45R55, respectively. After transplant and finishing under the same SR treatments, snapdragon flowered on average 7 days earlier under the B12G20R68 + FR treatment than the other LED treatments, whereas geranium (Pelargonium ×hortorum) grown under B45R55 and B12G20R68 + FR flowered 7 to 9 days earlier than those under the B10G5R85 and B10R90 treatments. Seedlings of each species grown under the HPS10 treatment accumulated less dry weight and took longer to flower compared with seedlings under the other SR treatments. We conclude that radiation quality of SR has relatively little effect on seedling growth and subsequent flowering although in some crops, flowering may be earlier when SR includes FR radiation.

Contributor Notes

This work was supported by the USDA National Institute of Food and Agriculture, Hatch project 192266.

We gratefully acknowledge support by the USDA National Institute of Food and Agriculture’s Specialty Crop Research Initiative, the USDA-ARS Floriculture and Nursery Research Initiative, C. Raker and Sons for donation of plant material, Philips for donation of LED fixtures, and Nate DuRussel for technical assistance. We also thank Jennifer Boldt and Ryan Warner for their critical review of this manuscript.

Former Graduate Student.

Professor and Floriculture Extension Specialist.

Corresponding author. E-mail: runkleer@msu.edu.

Article Sections

Article Figures

  • View in gallery

    The relative spectral distributions and estimated phytochrome photoequilibria (PPE) of supplemental radiation treatments between 400 and 800 nm from high-pressure sodium (HPS) and light-emitting diodes delivering different percentages (denoted in subscript) of blue (B; 400–500 nm), green (G; 500–600 nm), red (R; 600–700 nm), and far red (FR; 700–800 nm) radiation.

  • View in gallery

    Plant height of five seedling crops grown under ambient greenhouse radiation and supplemental lighting from two high-pressure sodium (HPS) or four light-emitting diode (LED) treatments delivering different percentages of blue (B; 400–500 nm), green (G; 500–600 nm), red (R; 600–700 nm), and far red (FR; 700–800 nm) radiation. All treatments delivered a photosynthetic photon flux density of 90 μmol·m−2·s–1, except HPS10, which delivered 10 μmol·m−2·s–1. For the LED treatments, subscript values denote the waveband proportions. ns = nonsignificant; means sharing a letter are not statistically different by Tukey’s honest significant difference test at P ≤ 0.05. Error bars indicate standard error.

  • View in gallery

    The leaf number and leaf area of five seedling crops grown under ambient greenhouse radiation and supplemental radiation from two high-pressure sodium (HPS) or four light-emitting diode treatments delivering different percentages of blue (B; 400–500 nm), green (G; 500–600 nm), red (R; 600–700 nm), and far red (FR; 700–800 nm) radiation. See caption for Fig. 2 for treatment and statistical information.

  • View in gallery

    Dry shoot and root weights of five seedling crops grown under ambient greenhouse radiation and supplemental radiation from two high-pressure sodium (HPS) or four light-emitting diode treatments delivering different percentages of blue (B; 400–500 nm), green (G; 500–600 nm), red (R; 600–700 nm), and far red (FR; 700–800 nm) radiation. See caption for Fig. 2 for treatment and statistical information.

  • View in gallery

    Days to flower after transplant, plant height at first flower, and total flower or inflorescence number of three seedling crops grown under ambient greenhouse radiation and supplemental radiation from two high-pressure sodium (HPS) or four light-emitting diode treatments delivering different percentages of blue (B; 400–500 nm), green (G; 500–600 nm), red (R; 600–700 nm), and far red (FR; 700–800 nm) radiation. For petunia, the y axis values for flower number are divided by three, as noted. See caption for Fig. 2 for treatment and statistical information.

Article References

  • AhmadM.GrancherN.HeilM.BlackR.C.GiovaniB.GallandP.LardemerD.2002Action spectrum for cryptochrome-dependent hypocotyl growth inhibition in ArabidopsisPlant Physiol.129774785

    • Search Google Scholar
    • Export Citation
  • BallaréC.M.ScopelA.L.SánchezR.A.1991Photocontrol of stem elongation in plant neighbourhoods: Effects of photon fluence rate under natural conditions of radiationPlant Cell Environ.50522529

    • Search Google Scholar
    • Export Citation
  • BlanchardM.G.RunkleE.S.FisherP.R.2011Modeling plant morphology and development of petunia in response to temperature and photosynthetic daily light integralSci. Hort.129313320

    • Search Google Scholar
    • Export Citation
  • BourgetC.M.2008An introduction to light-emitting diodesHortScience4319441946

  • BrownC.S.SchuergerA.C.SagerJ.C.1995Growth and photomorphogenesis of pepper plants under red light-emitting diodes with supplemental blue or far-red lightingJ. Amer. Soc. Hort. Sci.120808813

    • Search Google Scholar
    • Export Citation
  • BulaR.J.MorrowR.C.TibbittsT.W.BartaD.J.IgnatiusR.W.MartinT.S.1991Light-emitting diodes as a radiation source for plantsHortScience26203205

    • Search Google Scholar
    • Export Citation
  • ChiaP.L.KubotaC.2010End-of-day far-red light quality and dose requirements for tomato rootstock hypocotyl elongationHortScience4515011506

    • Search Google Scholar
    • Export Citation
  • FaustJ.E.HolcombeV.RajapakseN.C.LayneD.R.2005The effect of daily light integral on bedding plant growth and floweringHortScience40645649

    • Search Google Scholar
    • Export Citation
  • FoltaK.M.CarvalhoS.D.2015Photoreceptors and control of horticultural plant traitsHortScience5012741280

  • FoltaK.M.ChildersK.S.2008Light as a growth regulator: Controlling plant biology with narrow-bandwidth solid-state lighting systemsHortScience4319571964

    • Search Google Scholar
    • Export Citation
  • FranklinK.WhitelamG.2005Phytochromes and shade-avoidance responses in plantsAnn. Bot.96169175

  • GoinsG.D.YorioN.C.SanwoM.M.BrownC.S.1997Photomorphogenesis, photosynthesis, and seed yield of wheat plants grown under red light-emitting diodes (LEDs) with and without supplemental blue lightingJ. Expt. Bot.4814071413

    • Search Google Scholar
    • Export Citation
  • HernandezR.KubotaC.2012Tomato seedling growth and morphological responses to supplemental LED lighting red:blue ratios under varied daily solar light integralsActa Hort.956187194

    • Search Google Scholar
    • Export Citation
  • HernandezR.KubotaC.2014Growth and morphological response of cucumber seedlings to supplemental red and blue photon flux ratios under varied solar daily light integralsSci. Hort.1739299

    • Search Google Scholar
    • Export Citation
  • HoeneckeM.E.BulaR.J.TibbittsT.W.1992Importance of ‘blue’ photon levels for lettuce seedlings grown under red-light-emitting diodesHortScience27427430

    • Search Google Scholar
    • Export Citation
  • IslamA.M.KuwarG.ClarkeJ.L.BlystadD.R.GislerødH.R.OlsenJ.E.TorreS.2012Artificial light from light emitting diodes (LEDs) with a high portion of blue light results in shorter poinsettias compared to high pressure sodium (HPS) lampsSci. Hort.184171178

    • Search Google Scholar
    • Export Citation
  • KorczynskiP.C.LoganJ.FaustJ.E.2002Mapping monthly distribution of daily light integrals across the contiguous United StatesHortTechnology121216

    • Search Google Scholar
    • Export Citation
  • LopezR.G.RunkleE.S.2008Photosynthetic daily light integral during propagation influences rooting and growth of cuttings and subsequent development of New Guinea impatiens and petuniaHortScience4320522059

    • Search Google Scholar
    • Export Citation
  • MengQ.RunkleE.S.2014Controlling flowering of photoperiodic ornamental crops with light-emitting diode lamps: A coordinated grower trialHortTechnology24702711

    • Search Google Scholar
    • Export Citation
  • MitchellC.A.DzakovichM.P.GomezC.LopezR.BurrJ.F.HernaìndezR.KubotaC.CurreyC.J.MengQ.RunkleE.S.BourgetC.M.MorrowR.C.BothA.J.2015Light-emitting diodes in horticultureHort. Rev.43187

    • Search Google Scholar
    • Export Citation
  • MorrowR.C.2008LED lighting in horticultureHortScience4319471950

  • ParkY.RunkleE.S.2017Far-red radiation promotes growth of seedlings by increasing leaf expansion and whole-plant net assimilationEnviron. Expt. Bot.1364149

    • Search Google Scholar
    • Export Citation
  • PoelB.R.RunkleE.S.2017Seedling growth is similar under supplemental greenhouse lighting from high-pressure sodium lamps or light-emitting diodesHortScience52388394

    • Search Google Scholar
    • Export Citation
  • PramukL.A.RunkleE.S.2005Photosynthetic daily light integral during the seedling stage influences subsequent growth and flowering of Celosia, Impatiens, Salvia, Tagetes, and ViolaHortScience4013361339

    • Search Google Scholar
    • Export Citation
  • RandallW.C.LopezR.G.2014Comparisons of supplemental lighting from high-pressure sodium lamps and light-emitting diodes during bedding plant seedling productionHortScience49589595

    • Search Google Scholar
    • Export Citation
  • RandallW.C.LopezR.G.2015Comparisons of bedding plant seedlings grown under sole-source light-emitting diodes (LEDs) and greenhouse supplemental lighting from LEDs and high-pressure sodium lampsHortScience50705713

    • Search Google Scholar
    • Export Citation
  • RunkleE.S.HeinsR.D.2001Specific functions of red, far red and blue light in flowering and stem extension of long-day plantsJ. Amer. Soc. Hort. Sci.126275282

    • Search Google Scholar
    • Export Citation
  • RunkleE.S.HeinsR.D.2003Photocontrol and flowering and extension growth in the long-day plant pansyJ. Amer. Soc. Hort. Sci.128479485

  • SagerJ.C.SmithW.O.EdwardsJ.L.CyrK.L.1988Photosynthetic efficiency and phytochrome photoequilibria determination using spectral dataTrans. Amer. Soc. Agr. Eng.3118821889

    • Search Google Scholar
    • Export Citation
  • SamsC.E.KopsellD.MorrowR.C.2016Light quality impacts on growth, flowering, mineral uptake and petal pigmentation of marigoldActa Hort.1134139146

    • Search Google Scholar
    • Export Citation
  • SmithH.1982Light quality, photoperception, and plant strategyAnnu. Rev. Plant Physiol.33481518

  • TripathyB.C.BrownC.S.1995Root-shoot interaction in the greening of wheat seedlings grown under red lightPlant Physiol.107407411

  • VaidT.M.RunkleE.S.FrantzJ.M.2014Mean daily temperature regulates plant quality attributes of annual ornamental plantsHortScience49574580

    • Search Google Scholar
    • Export Citation
  • WallaceC.BothA.J.2016Evaluating operating characteristics of light sources for horticultural applicationsActa Hort.1134435444

  • WollaegerH.M.RunkleE.S.2015Growth and acclimation of impatiens, salvia, petunia, and tomato seedlings to blue and red lightHortScience50522529

    • Search Google Scholar
    • Export Citation
  • ZhaoX.YuX.FooE.SymonsG.M.LopezJ.BendehakkaluK.T.XiangJ.WellerJ.L.LiuX.ReidJ.B.2007A study of gibberellin homeostasis and cryptochrome-mediated blue light inhibition of hypocotyl elongationPlant Physiol.145106118

    • Search Google Scholar
    • Export Citation

Article Information

Google Scholar

Related Content

Article Metrics

All Time Past Year Past 30 Days
Abstract Views 151 151 7
Full Text Views 89 89 2
PDF Downloads 11 11 0