Special Issue "Control of LED Lighting Based on Plant Physiological Principles"

A special issue of Agronomy (ISSN 2073-4395). This special issue belongs to the section "Horticultural and Floricultural Crops".

Deadline for manuscript submissions: closed (15 June 2020).

Special Issue Editor

Prof. Dr. Byoung Ryong Jeong
Website SciProfiles
Guest Editor
Department of Horticulture, Division of Applied Life Science, Graduate School, Gyeongsang National University (GNU), Jinju 52828, Korea
Interests: floriculture; transplants (micropropagated & plug); silicon in horticulture; plant factory; protected horticulture; hydroponics

Special Issue Information

Dear Colleagues,

Light is the primary energy source and the most important regulatory factor in the life cycle of plants. Light drives photosynthesis in plants, helping them to build carbon-based materials, and further acts as an environmental signal. Plants respond to the intensity, wavelength, duration, and direction of light. Light emitting diodes (LEDs), recently applied widely for plant cultures, are environmentally-friendly and long-lasting light sources available in the spectral range covering the entire visible and near-UV regions, and supersede conventional lamps in efficiency. This Speical Issue on the “Control of LED Lighting Based on Plant Physiological Principles” will focus on the the broad area of plant growth and development including, but not limited to, germination, seedling establishment, photomorphogenesis, and the phase transition and flowering of plants using LED lighting technology.

Prof. Byoung Ryong Jeong
Guest Editor

Manuscript Submission Information

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Keywords

  • Cryptochrome
  • Flowering
  • Light direction
  • Light duration
  • Light intensity
  • Light signal
  • Light quality
  • Photomorphogenesis
  • Photoreceptor
  • Phytochrome

Published Papers (11 papers)

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Research

Open AccessArticle
Effect of Light Spectrum on Gas Exchange, Growth and Biochemical Characteristics of Einkorn Seedlings
Agronomy 2020, 10(7), 1042; https://doi.org/10.3390/agronomy10071042 - 19 Jul 2020
Abstract
The use of Light Emitting Diode (LED) lights in microscale vegetable production is more and more widespread. In this context, the effect of light spectrum on photosynthesis, growth, shoot yield, pigment content, and nutritional status of einkorn seedlings (Triticum monococcum L. ssp. [...] Read more.
The use of Light Emitting Diode (LED) lights in microscale vegetable production is more and more widespread. In this context, the effect of light spectrum on photosynthesis, growth, shoot yield, pigment content, and nutritional status of einkorn seedlings (Triticum monococcum L. ssp. monococcum), germinated and grown in a nutrient solution, was investigated. Plants were subjected to six different LED light treatments, all having a photon flux density (PFD) of 200 μmol m−2 s−1. Two light treatments were monochromatic (red or blue), three dichromatic (blue and red in the proportion), and one of a wider spectrum (selected as a control). All the light treatments affected the morphological, biochemical, and nutritional status of einkorn seedlings. Overall, the dichromatic treatments were the most effective in stimulating biomass production, CO2 assimilation, and evapotranspiration, as well as contents in chlorophyll a and b and carotenoids, and additionally nitrogen, phosphorous, manganese, iron, and zinc. These results are of relevance for the beneficial effects of dichromatic LED treatments in maximizing einkorn shoot yield and nutritional values, and in limiting energy consumption in indoor cultivation. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
A Novel New Light Recipe Significantly Increases the Growth and Yield of Sweet Basil (Ocimum basilicum) Grown in a Plant Factory System
Agronomy 2020, 10(7), 934; https://doi.org/10.3390/agronomy10070934 - 29 Jun 2020
Abstract
Light is a crucial element for plant growth and production. High-pressure sodium (HPS) lamps are considered not very electrically efficient as they generate high radiant heat, and as a consequence, there has been a lot of interest in replacing HPS lamps with new [...] Read more.
Light is a crucial element for plant growth and production. High-pressure sodium (HPS) lamps are considered not very electrically efficient as they generate high radiant heat, and as a consequence, there has been a lot of interest in replacing HPS lamps with new more efficient lighting sources in the form of light-emitting diodes (LEDs). LEDs have a linear photon output with the electrical input current, and this great feature allows the design of lighting arrays that match the plant’s needs. In the current study, light spectrum absorbance of pigments extracted from 14 plant species was analyzed. Two absorbance peaks were observed in the Photosynthetically Active Radiation (PAR) region: one at 435 nm and the other at 665 nm. The light spectrum array was designed to produce the spectrum absorbed by basil pigments. This included the use of new wavelengths of 435 ± 5 nm to cover the blue region. Moreover, the ratio between blue and red was considered to match the absorbance of basil pigment. The use of a light spectrum that matches the plant absorbance significantly improved the investigated physiological parameters and increased the growth yield of basil. Moreover, this is the first to confirm the great positive impact of using 435 nm light spectrum in comparison with the commercially widely used 450 nm LED spectrum. This investigation has great scientific and commercial applications in the field of indoor faming and plant factory systems. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Genotype × Light Quality Interaction on Rose Architecture
Agronomy 2020, 10(6), 913; https://doi.org/10.3390/agronomy10060913 - 25 Jun 2020
Abstract
Plant shape, and thereby plant architecture, is a major component of the visual quality of ornamental plants. Plant architecture results from growth and branching processes and is dependent on genetic and environmental factors such as light quality. The effects of genotype and light [...] Read more.
Plant shape, and thereby plant architecture, is a major component of the visual quality of ornamental plants. Plant architecture results from growth and branching processes and is dependent on genetic and environmental factors such as light quality. The effects of genotype and light quality and their interaction were evaluated on rose bush architecture. In a climatic growth chamber, three cultivars (Baipome, Knock Out® Radrazz and ‘The Fairy’) with contrasting architecture were exposed to three different light spectra, using white (W), red (R), and far-red (FR) light-emitting diodes (LEDs), i.e., W, WR, and WRFR. The R/FR ratio varied between treatments, ranging from 7.5 for WRFR to 23.2 for WR. Light intensity (224.6 μmol m−2 s−1) was the same for all treatments. Plants were grown up to the order 1 axis flowering stage, and their architecture was digitized at two observation scales—plant and axis. Highly significant genotype and light quality effects were revealed for most of the variables measured. An increase in stem length, in the number of axes and in the number of flowered axes was observed under the FR enriched light, WRFR. However, a strong genotype × light quality interaction, i.e., a genotype-specific response was highlighted. More in-depth eco-physiological and biochemical investigations are needed to better understand rose behavior in response to light quality and thus identify the determinants of the genotype × light quality interaction. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
The Photosynthetic Performance of Red Leaf Lettuce under UV-A Irradiation
Agronomy 2020, 10(6), 761; https://doi.org/10.3390/agronomy10060761 - 27 May 2020
Abstract
The objective of this study was to evaluate how different UV-A wavelengths influence the morphology and photosynthetic behavior of red-leaf lettuce (Lactuca sativa L. cv. Maiko). In the experiments, the main photosynthetic photon flux consisted of red (R) and blue (B) light, [...] Read more.
The objective of this study was to evaluate how different UV-A wavelengths influence the morphology and photosynthetic behavior of red-leaf lettuce (Lactuca sativa L. cv. Maiko). In the experiments, the main photosynthetic photon flux consisted of red (R) and blue (B) light, supplemented with equal doses of different UV-A wavelengths (402, 387 and 367 nm). Treating the crops with low dosages of specific narrow-band UV-A radiation at key points in the life cycle initiated a cascade of responses in the above-ground biomass. According to the results, red-leaf lettuces acclimated to longer UV-A wavelengths by increasing biomass production, whereas different UV-A wavelengths had no significant effect on plant senescence reflectance, nor on the normalized difference vegetation index. A significant decrease in the maximum quantum yield of the PSII photochemistry of dark (Fv/Fm) and light (ΦPSII) adapted plants was observed. A lack of significant changes in non-photochemical fluorescence quenching indicates that photo-inhibition occurred under RBUV367, whereas the photosynthetic response under RB, RBUV402, and RBUV387 suggests that there was no damage to PSII. The correlation of the photosynthetic rate (Pr) with the stomatal conductance (gs) indicated that the increase in the Pr of lettuce under supplemental UV-A radiation was due to the increase of gs, instead of the ratio of the intracellular to ambient CO2 content (Ci/Ca) or stomatal limitations. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Morpho-Physiological Responses of Pisum sativum L. to Different Light-Emitting Diode (LED) Light Spectra in Combination with Biochar Amendment
Agronomy 2020, 10(3), 398; https://doi.org/10.3390/agronomy10030398 - 14 Mar 2020
Abstract
Light quality and nutrient availability are the primary factors that influence plant growth and development. In a research context of improving indoor plant cultivation while lowering environmental impact practices, we investigated the effect of different light spectra, three provided by light-emitting diodes (LEDs), [...] Read more.
Light quality and nutrient availability are the primary factors that influence plant growth and development. In a research context of improving indoor plant cultivation while lowering environmental impact practices, we investigated the effect of different light spectra, three provided by light-emitting diodes (LEDs), and one by a fluorescent lamp, on the morpho-physiology of Pisum sativum L. seedlings grown in the presence/absence of biochar. We found that all morpho-physiological traits are sensitive to changes in the red-to-far-red light (R:FR) ratio related to the light spectra used. In particular, seedlings that were grown with a LED type characterized by the lowest R:FR ratio (~2.7; AP67), showed good plant development, both above- and belowground, especially when biochar was present. Biochar alone did not affect the physiological traits, which were influenced by the interplay with lighting type. AP67 LED type had a negative impact only on leaf fluorescence emission in light conditions, which was further exacerbated by the addition of biochar to the growing media. However, we found that the combination of biochar with a specific optimal light spectrum may have a synergetic effect enhancing pea seedling physiological performances and fruit yield and fostering desired traits. This is a promising strategy for indoor plant production while respecting the environment. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Effect of Supplementary Lighting Duration on Growth and Activity of Antioxidant Enzymes in Grafted Watermelon Seedlings
Agronomy 2020, 10(3), 337; https://doi.org/10.3390/agronomy10030337 - 02 Mar 2020
Cited by 1
Abstract
Insufficient exposure to light in the winter may result in a longer production periods and lower quality of seedlings in greenhouses for plug growers. Supplementary artificial lighting to plug seedlings may be one solution to this problem. The objective of this study was [...] Read more.
Insufficient exposure to light in the winter may result in a longer production periods and lower quality of seedlings in greenhouses for plug growers. Supplementary artificial lighting to plug seedlings may be one solution to this problem. The objective of this study was to assess the effects of the duration of the supplementary light on the growth and development of two watermelon cultivars, ‘Speed’ and ‘Sambok Honey’ grafted onto ‘RS-Dongjanggun’ bottle gourd rootstocks (Lagenaria siceraria Stanld). Seedlings were grown for 10 days in a glasshouse with an average daily natural light intensity of 340 μmol·m−2·s−1 photosynthetic photon flux density (PPFD) and daily supplementary lighting of 8, 12 or 16 h from mixed LEDs (W1R2B1, chip ratio of white:red:blue = 1:2:1) at a light intensity of 100 μmol·m−2·s−1 PPFD, a group without supplementary light was set as the control (CK). The culture environment in a glasshouse had 25/15 °C day/night temperatures, an 85 ± 5% relative humidity, and a natural photoperiod of 8 h. The results showed that all the growth and development parameters of seedlings grown with supplementary light were significantly greater than those without supplementary light (CK). The 12 and 16 h supplementary light resulted in greater growth and development parameters than the 8 h supplementary light did. The same trend was also found with the indexes that reflect the quality of the seedlings, such as the dry weight ratio of the shoot and root, total biomass, dry weight to height ratio of scions, and specific leaf weight. The 12 h and 16 h light supplements resulted in greater Dickson’s quality indexes compared to the 8 h supplementary light, and the 12 h supplementary light showed the greatest use efficiency of the supplementary light. 16 h of daily supplementary light significantly increased the H2O2 content and the antioxidant enzyme activities in seedlings compared to the other treatments. This indicated that 16 h of supplementary light led to certain stresses in watermelon seedlings. In conclusion, considering the energy consumption, 12 h of supplementary light was the most efficient in improving the quality of the two cultivars of grafted watermelon plug seedlings. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Growth, Photosynthesis, and Physiological Responses of Ornamental Plants to Complementation with Monochromic or Mixed Red-Blue LEDs for Use in Indoor Environments
Agronomy 2020, 10(2), 284; https://doi.org/10.3390/agronomy10020284 - 16 Feb 2020
Abstract
Inch (Tradescantia zebrina) and spider (Chlorophytum comosum) plants were grown in a growth chamber for two months in plastic containers to evaluate the effects of different light treatments (TO Tube luminescent Dunn (TLD) lamps or control), TB [...] Read more.
Inch (Tradescantia zebrina) and spider (Chlorophytum comosum) plants were grown in a growth chamber for two months in plastic containers to evaluate the effects of different light treatments (TO Tube luminescent Dunn (TLD) lamps or control), TB (TLD lamps + blue light emitting diodes (LEDs)), TR (TLD lamps + red LEDs), and TBR (TLD lamps + blue and red LEDs) on biomass, photosynthesis, and physiological parameters. Total dry weight and water content were evaluated at the end of the experimental period. After two months, pigment concentrations and the photosynthetic rate were assessed in both species. The total soluble sugar, starch, and proline concentrations in the leaf as physiological parameters were studied at the end of the experiment. Both species had increased root, shoot, and total dry weight under blue LEDs conditions. The chlorophyll concentration showed a specific response in each species under monochromic or mixed red-blue LEDs. The highest photosynthetic rate was measured under the addition of mixed red-blue LEDs with TLD lamps. At the physiological level, each species triggered different responses with respect to total soluble sugars and the proline concentration in leaves under monochromic or mixed red-blue LEDs. Our study demonstrated that the addition of blue LEDs is advisable for the production of these ornamental foliage species. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Fittonia verschaffeltii Response to Artificial Light Treatments: BIOMASS, Nutrient Concentrations and Physiological Changes
Agronomy 2020, 10(1), 126; https://doi.org/10.3390/agronomy10010126 - 15 Jan 2020
Cited by 1
Abstract
The purpose of the present study was to evaluate the effects of different light treatments on biomass, nutrient concentrations and physiological parameters of Fittonia verschaffeltii (Lem) Van Houtte. The aim was to establish a methodology to evaluate the effect of photosynthetically active radiation [...] Read more.
The purpose of the present study was to evaluate the effects of different light treatments on biomass, nutrient concentrations and physiological parameters of Fittonia verschaffeltii (Lem) Van Houtte. The aim was to establish a methodology to evaluate the effect of photosynthetically active radiation (PAR) emitted by lamps on biomass. The light treatments used were tube luminescent Dunn (TL-D), tube luminescent Dunn + light emitting diodes (LEDs) and Tube luminescent 5 (TL-5). At the end of the experimental period, biomass, nutritional, biochemical, and physiological parameters were assessed. A clear reduction in total plant dry weight under TL-D + LEDs at the end of the experiment was recorded. With respect to nutrient concentration in the different organs assessed, there was no clear response under the different light treatments. The growth under TL-D lamps resulted in the highest concentration of total soluble sugars and starch in leaves, whereas the highest value of indole 3-acetic acid concentration was under TL-5 lamps. Plants grown under TL-D + LEDs showed the lowest values of chlorophyll a, b and a + b. The relationship proposed between integrated use of spectral energy (IUSE) and total dry weight (TDW) showed a good correlation with an R2 value of 0.86, therefore we recommend this methodology to discern the effects of the different spectral qualities on plant biomass. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Effect of Light Intensity on Rooting and Growth of Hydroponic Strawberry Runner Plants in a LED Plant Factory
Agronomy 2019, 9(12), 875; https://doi.org/10.3390/agronomy9120875 - 11 Dec 2019
Abstract
To rapidly produce strawberry (Fragaria × ananassa Duch. cv. Benihoppe) transplants from cuttings, suitable light intensities for unrooted runner plants at the rooting stage and rooted runner plants at the seedling stage were determined in a plant factory under LED lighting. At [...] Read more.
To rapidly produce strawberry (Fragaria × ananassa Duch. cv. Benihoppe) transplants from cuttings, suitable light intensities for unrooted runner plants at the rooting stage and rooted runner plants at the seedling stage were determined in a plant factory under LED lighting. At the rooting stage, unrooted runner plants at the 3-leaf stage were hydroponically rooted for 6 days under light intensity of 30, 90, 150, and 210 μmol m−2 s−1, respectively. At the seedling stage, rooted runner plants were hydroponically grown for 18 days under light intensity of 90, 180, 270, and 360 μmol m−2 s−1, respectively. The tube LED lights consisting of white and red LED chips were used as sole light source, and photoperiod was controlled as 16 h d−1. The results showed that the maximum root number (7.7) and longest root length (14.8 cm) of the runner plants were found under 90 μmol m−2 s−1 at the rooting stage. Photosynthetic activity in runner plant leaves under 90 μmol m−2 s−1 were higher than that under 30, 150, and 210 μmol m−2 s−1. Higher light intensity at the range of 90–270 μmol m−2 s−1 increased the stomatal conductance of newly formed leaves of rooted runner plants, thus improving the net photosynthetic rate and growth of rooted runner plants at the seedling stage. The crown diameter, shoot and root dry weights, and root to shoot ratio of rooted runner plants increased by 9.7%, 38.8%, 106.1%, and 48.7%, respectively, when the light intensity increased from 90 to 270 μmol m−2 s−1. However, there was no further improvement of runner plant growth under 360 μmol m−2 s−1. Furthermore, no significant difference of increased dry biomass per mole of photons delivered was found between 180 and 270 μmol m−2 s−1. In consideration of transplant quality and economic balance, light intensity of 90 μmol m−2 s−1 at the rooting stage and 270 μmol m−2 s−1 at the seedling stage were suggested for rapidly producing hydroponic strawberry transplants based on unrooted runner plants in the LED plant factory. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Optimal LED Wavelength Composition for the Production of High-Quality Watermelon and Interspecific Squash Seedlings Used for Grafting
Agronomy 2019, 9(12), 870; https://doi.org/10.3390/agronomy9120870 - 10 Dec 2019
Cited by 1
Abstract
Watermelon is cultivated worldwide and is mainly grafted onto interspecific squash rootstocks. Light-emitting diodes (LEDs) can be implemented as light sources during indoor production of both species and their spectral quality is of great importance. The objective of the present study was to [...] Read more.
Watermelon is cultivated worldwide and is mainly grafted onto interspecific squash rootstocks. Light-emitting diodes (LEDs) can be implemented as light sources during indoor production of both species and their spectral quality is of great importance. The objective of the present study was to determine the optimal emission of LEDs with wide wavelength for the production of watermelon and interspecific squash seedlings in a growth chamber. Conditions were set at 22/20 °C temperature (day/night), 16 h photoperiod, and 85 ± 5 μmol m−2 s−1 photosynthetic photon flux density. Illumination was provided by fluorescent (FL, T0) lamps or four LEDs (T1, T2, T3, and T4) emitting varying wide spectra. Watermelon seedlings had greater shoot length, stem diameter, cotyledon area, shoot dry weight-to-length (DW/L) ratio, and Dickson’s quality index (DQI) under T1 and T3, while leaf area and shoot dry weight (DW) had higher values under T1. Interspecific squash seedlings had greater stem diameter, and shoot and root DW under T1 and T3, while leaf and cotyledon areas were favored under T1. In both species, T0 showed inferior development. It could be concluded that a light source with high red emission, relatively low blue emission, and a red:far-red ratio of about 3 units seems ideal for the production of high-quality watermelon (scion) and interspecific squash (rootstock) seedlings. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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Open AccessArticle
Both Multi-Segment Light Intensity and Extended Photoperiod Lighting Strategies, with the Same Daily Light Integral, Promoted Lactuca sativa L. Growth and Photosynthesis
Agronomy 2019, 9(12), 857; https://doi.org/10.3390/agronomy9120857 - 06 Dec 2019
Abstract
With the rise of plant factories around the world, more and more crops are cultivated under artificial light. Studies on effects of lighting strategies on plant growth, such as different light intensities, photoperiods, and their combinations, have been widely conducted. However, research on [...] Read more.
With the rise of plant factories around the world, more and more crops are cultivated under artificial light. Studies on effects of lighting strategies on plant growth, such as different light intensities, photoperiods, and their combinations, have been widely conducted. However, research on application of multi-segment light strategies and associated plant growth mechanisms is still relatively lacking. In the present study, two lighting strategies, multi-segment light intensity and extended photoperiod, were compared with a constant light intensity with a 12 h light/12 h dark cycle and the same daily light integral (DLI). Both lighting strategies promoted plant growth but acted via different mechanisms. The multi-segment light intensity lighting strategy promoted plant growth by decreasing non-photochemical quenching (NPQ) of the excited state of chlorophyll and increasing the quantum yield of PSII electron transport (PhiPSII), quantum yield of the carboxylation rate (PhiCO2), and photochemical quenching (qP), also taking advantage of the circadian rhythm. The extended photoperiod lighting strategy promoted plant growth by compensating for weak light stress and increasing light-use efficiency by increasing chlorophyll content under weak light conditions. Full article
(This article belongs to the Special Issue Control of LED Lighting Based on Plant Physiological Principles)
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