Supplemental But Not Photoperiodic Lighting Increased Seedling Quality and Reduced Production Time of Annual Bedding Plants

in HortScience

In northern latitudes, the photosynthetic daily light integral can be less than 5 mol·m–2·d–1, necessitating the use of supplemental lighting (SL) to reduce bedding plant seedling production time and increase quality. Our objectives were 1) to quantify seedling quality and production time under continuous 16-h or instantaneous threshold SL, continuous low-intensity photoperiodic lighting (PL) for 16 or 24 hours with and without far-red light, or no electric lighting; and 2) to determine whether the described lighting treatments during propagation impact finished plant quality or flowering. Seeds of begonia (Begonia ×semperflorens) ‘Bada Bing Scarlet’, gerbera (Gerbera jamesonii) ‘Jaguar Deep Orange’, impatiens (Impatiens walleriana) ‘Accent Premium Salmon’, petunia (Petunia ×hybrida) ‘Ramblin Peach Glo’, and tuberous begonia (Begonia ×tuberosa) ‘Nonstop Rose Petticoat’ were sown in 128-cell trays and grown under either SL, PL, or no electric lighting (control). SL treatments consisted of high-intensity light-emitting diode (LED) or high-pressure sodium (HPS) lamps providing a photosynthetic photon flux density (PPFD) of either 70 µmol·m–2·s–1 on continuously for 16 h·d–1 or 90 µmol·m–2·s–1 based on an instantaneous threshold. PL treatments consisted of low-intensity red:white (R:W) or red:white:far-red (R:W:FR) lamps for 16 h·d–1 or R:W:FR lamps for 24 h·d–1. Seedlings of gerbera, impatiens, and petunia from each treatment were subsequently transplanted and finished in a common greenhouse environment. The highest quality seedlings were grown under SL compared with PL or control conditions. When comparing SL treatments, seedlings produced under HPS or LED SL using an instantaneous threshold were of equal or greater quality compared with those under continuous SL with a 16-h photoperiod. Although the greater leaf area and internode elongation under PL may give growers the perception that seedling production time is reduced, PL did not increase biomass accumulation and seedling quality. Petunia seedlings propagated under HPS lamps using an instantaneous threshold flowered 4 to 11 days earlier compared with the other SL treatments. In addition, petunia propagated under R:W:FR PL for 16 h·d–1 flowered 5 to 7 days earlier compared with LED SL and the other PL treatments.

Contributor Notes

This work was supported by the U.S. Department of Agriculture (USDA) National Institute of Food and Agriculture, Hatch project MICL02472.

We gratefully acknowledge support by the USDA-Agricultural Research Service Floriculture and Nursery Research Initiative, Philips Lighting, Hort Americas, The Western Michigan Greenhouse Association, and The Metro Detroit Flower Growers Association for funding; Ball Horticultural Co. for seeds; Raker-Roberta’s for plant material; The Blackmore Company for fertilizer; and Nathan DuRussel for technical assistance.

The use of trade names in this publication does not imply endorsement by Michigan State University or Colorado State University of products named nor criticism of similar ones not mentioned.

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

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    Spectral quality delivered from high-intensity 400-W high-pressure sodium lamps (A) or 200-W light-emitting diode lamps (B) at a photosynthetic photon flux density (PPFD) from 400–700 nm of 90 µmol·m–2·s–1, 15-W red:white (C), or 10-W red:white:far-red (D) flowering lamps at a PPFD of 2 µmol·m–2·s–1 at canopy level.

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    Stem length (A), stem diameter (B), root dry mass (C), shoot dry mass (D), sturdiness quotient (E), and quality index (F) for begonia, gerbera, impatiens, petunia, and tuberous begonia seedlings collected 42, 28, 28, 28, and 42 d after germination, respectively, grown under continuous supplemental lighting with a 16-h photoperiod provided by high-pressure sodium (HPS_70) or light-emitting diode (LED_70) lamps at a photosynthetic photon flux density (PPFD) of 70 µmol·m–2·s–1; supplemental lighting based on an instantaneous threshold (on from 0600 to 0800 hr and 1700 to 2200 hr, and on between 0800 and 1700 hr when outside PPFD was less than ≈440 µmol·m–2·s–1) provided by HPS (HPS_90) or LED (LED_90) lamps at a PPFD of 90 µmol·m–2·s–1; photoperiodic lighting provided by 15-W red:white flowering lamps with a 16-h photoperiod (R:W), 10-W red:white:far-red flowering lamps with a 16-h photoperiod (R:W:FR), or 10-W red:white:far-red flowering lamps with a 24-h photoperiod (24-h); or no supplemental or photoperiodic lighting (Natural). Means sharing a letter are not statistically different by Tukey’s honestly significant difference test at P ≤ 0.05.

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    Leaf area (A) and number (B) for impatiens and petunia seedlings collected 28 d after germination grown under continuous supplemental lighting with a 16-h photoperiod provided by high-pressure sodium (HPS_70) or light-emitting diode (LED_70) lamps at a photosynthetic photon flux density (PPFD) of 70 µmol·m–2·s–1; supplemental lighting based on an instantaneous threshold (on from 0600 to 0800 hr and 1700 to 2200 hr, and on between 0800 and 1700 hr when outside PPFD was less than ≈440 µmol·m–2·s–1) provided by HPS (HPS_90) or LED (LED_90) lamps at a PPFD of 90 µmol·m–2·s–1; photoperiodic lighting provided by either 15-W red:white flowering lamps with a 16-h photoperiod (R:W), 10-W red:white:far-red flowering lamps with a 16-h photoperiod (R:W:FR), or 10-W red:white:far-red flowering lamps with a 24-h photoperiod (24-h); or no supplemental or photoperiodic lighting (Natural). Means sharing a letter are not statistically different by Tukey’s honestly significant difference test at P ≤ 0.05.

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    Days to visible bud (A), days to flower (B), node number (C), bud number (D), width (E), and height (F) at finishing for gerbera, impatiens, and petunia seedlings propagated under continuous supplemental lighting with a 16-h photoperiod provided by high-pressure sodium (HPS_70) or light-emitting diode (LED_70) lamps at a photon flux density (PPFD) of 70 µmol·m–2·s–1; supplemental lighting based on an instantaneous threshold (on from 0600 to 0800 hr and 1700 to 2200 hr, and on between 0800 and 1700 hr when outside PPFD was less than ≈440 µmol·m–2·s–1) provided by HPS (HPS_90) or LED (LED_90) lamps at a PPFD of 90 µmol·m–2·s–1; photoperiodic lighting provided by either 15-W red:white flowering lamps with a 16-h photoperiod (R:W), 10-W red:white:far-red flowering lamps with a 16-h photoperiod (R:W:FR), or 10-W red:white:far-red flowering lamps with a 24-h photoperiod (24-h); or no supplemental or photoperiodic lighting (Natural). Means sharing a letter are not statistically different by Tukey’s honestly significant difference test at P ≤ 0.05.

Article References

  • ArthurJ.W.GuthrieJ.D.NewellJ.M.1930Some effects of artificial climates on the growth and chemical composition of plantsAmer. J. Bot.17416482

    • Search Google Scholar
    • Export Citation
  • BothA.J.BugbeeB.KubotaC.LopezR.G.MitchellC.RunkleE.S.WallaceC.2017Proposed product label for electric lamps used in the plant sciencesHortTechnology27544549

    • Search Google Scholar
    • Export Citation
  • CraigD.S.RunkleE.S.2012Using LEDs to quantify the effect of the red to far-red ratio of night-interruption lighting on flowering of photoperiodic cropsActa Hort.956179186

    • Search Google Scholar
    • Export Citation
  • CurreyC.J.TorresA.P.LopezR.G.JacobsD.F.2013The quality index: A new tool for integrating quantitative measurements to assess quality of young floriculture plantsActa Hort.1000385391

    • Search Google Scholar
    • Export Citation
  • DownsR.J.ThomasJ.F.1982Phytochrome regulation of flowering in the long-day plant, Hyoscyamus nigerPlant Physiol.70898900

  • ErwinJ.MattsonN.WarnerR.2017Light effects on bedding plants p. 119−134. In: R. Lopez and E. Runkle (eds.). Light management in controlled environments. Meister Media Worldwide Willoughby OH

  • FaustJ.E.HeinsR.D.1997Quantifying the influence of high-pressure sodium lighting on shoot-tip temperatureActa Hort.4188591

  • FranklinK.A.2008Shade avoidanceNew Phytol.179930944

  • FranklinK.A.WhitelamG.C.2005Phytochromes and shade-avoidance responses in plantsAnn. Bot.96169175

  • HernándezR.KubotaC.2016Physiological responses of cucumber seedlings under different blue and red photon flux ratios using LEDsEnviron. Expt. Bot.1216674

    • Search Google Scholar
    • Export Citation
  • HutchinsonV.A.CurreyC.J.LopezR.G.2012Photosynthetic daily light integral during root development influences subsequent growth and development of several herbaceous annual bedding plantsHortScience47856860

    • Search Google Scholar
    • Export Citation
  • LopezR.CurreyC.RunkleE.2017Light and young plants p. 109−118. In: R. Lopez and E. Runkle (eds.). Light management in controlled environments. Meister Media Worldwide Willoughby OH

  • 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
  • MassaG.D.KimH.WheelerR.M.MitchellC.A.2008Plant productivity in response to LED lightingHortScience4319511956

  • MattsonN.S.ErwinJ.E.2005The impact of photoperiod and irradiance on flowering of several herbaceous ornamentalsScientia Hort.104275292

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

  • NelsonJ.A.BugbeeB.2014Economic analysis of greenhouse lighting: Light emitting diodes vs. high intensity discharge fixturesPLoS One9e99010doi: 10.1371/journal.pone.0099010

    • Search Google Scholar
    • Export Citation
  • OhW.RunkleE.S.WarnerR.M.2010Timing and duration of supplemental lighting during the seedling stage influence quality and flowering in petunia and pansyHortScience4513321337

    • Search Google Scholar
    • Export Citation
  • OhyamaK.ManabeK.OmuraY.KozaiT.KubotaC.2005Potential use of a 24-hour photoperiod (continuous light) with altering air temperature for production of tomato plug transplants in a closed systemHortScience40374377

    • Search Google Scholar
    • Export Citation
  • 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.2014Comparison 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.2015Comparison 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.BothA.J.2017Delivering long-day lighting: Technology options and costs p. 91−99. In: R. Lopez and E. Runkle (eds.). Light management in controlled environments. Meister Media Worldwide Willoughby OH

  • 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
  • SparksB.2016Micandy gardens uses new technology and energy efficiency to stay ahead of the curve. 28 Aug. 2018. <https://www.greenhousegrower.com/management/ micandy-gardens-uses-new-technology-and-energy-efficiency-to-stay-ahead-of-the-curve/>

  • StyerC.2003Propagating seed crops p. 151–163. In: D. Hamrick (ed.). Ball redbook crop production: Volume two. 17th ed. Ball Publishing Batavia IL

  • ThomasB.Vince-PrueD.1997Photoperiodism in plants. 2nd ed. Academic Press London UK

  • Van IeperenW.SavvidesA.FanourakisD.2012Red and blue light effects during growth on hydraulic and stomatal conductance in leaves of young cucumber plantsActa Hort.956223230

    • Search Google Scholar
    • Export Citation
  • VlahosJ.C.1990Temperature and irradiance influence growth and development of three cultivars of AchimenesHortScience2515971598

  • WallaceC.BothA.J.2016Evaluating operating characteristics of light sources for horticultural applicationsActa Hort.1134435444

  • WarringtonI.J.NortonR.A.1991An evaluation of plant growth and development under various daily quantum integralsJ. Amer. Soc. Hort. Sci.116544551

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

    • Search Google Scholar
    • Export Citation
  • ZhangT.FoltaK.2012Green light signaling and adaptive responsePlant Signal. Behav.714

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