Tomatoes Grown with Light-emitting Diodes or High-pressure Sodium Supplemental Lights have Similar Fruit-quality Attributes

Light-emitting diodes (LEDs) are an attractive alternative to high-pressure sodium (HPS) lamps for plant growth because of their energy-saving potential. However, the effects of supplementing broad-waveband solar light with narrow-waveband LED light on the sensory attributes of greenhouse-grown tomatoes (Solanum lycopersicum) are largely unknown. Three separate studies investigating the effect of supplemental light quantity and quality on physicochemical and organoleptic properties of greenhouse-grown tomato fruit were conducted over 4- or 5-month intervals during 2012 and 2013. Tomato cultivars Success, Komeett, and Rebelski were grown hydroponically within a high-wire trellising system in a glass-glazed greenhouse. Chromacity, Brix, titratable acidity, electrical conductivity (EC), and pH measurements of fruit extracts indicated plant response differences between lighting treatments. In sensory panels, tasters ranked tomatoes for color, acidity, and sweetness using an objective scale, whereas color, aroma, texture, sweetness, acidity, aftertaste, and overall approval were ranked using hedonic scales. By collecting both physicochemical as well as sensory data, this study was able to determine whether statistically significant physicochemical parameters of tomato fruit also reflected consumer perception of fruit quality. Sensory panels indicated that statistically significant physicochemical differences were not noticeable to tasters and that tasters engaged in blind testing could not discern between tomatoes from different supplemental lighting treatments or unsupplemented controls. Growers interested in reducing supplemental lighting energy consumption by using intracanopy LED (IC-LED) supplemental lighting need not be concerned that the quality of their tomato fruits will be negatively affected by narrow-band supplemental radiation at the intensities and wavelengths used in this study.

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Supplemental Lighting Orientation and Red-to-blue Ratio of Light-emitting Diodes for Greenhouse Tomato Production

HortScience ◽

10.21273/hortsci.49.4.448 ◽

2014 ◽

Vol 49 (4) ◽

pp. 448-452 ◽

Cited By ~ 20

Author(s):

Paul Deram ◽

Mark G. Lefsrud ◽

Valérie Orsat

Keyword(s):

High Efficiency ◽

Light Emitting Diodes ◽

Tomato Fruit ◽

Fruit Production ◽

Plant Production ◽

Tomato Production ◽

Light Emitting ◽

Led Light ◽

Red Led ◽

Supplemental Lighting

Current greenhouse supplemental lighting technology uses broad-spectrum high-pressure sodium lamps (HPS) that, despite being an excellent luminous source, are not the most efficient light source for plant production. Specific light frequencies in the 400- to 700-nm range have been shown to affect photosynthesis more directly than other wavelengths (especially in the red and blue ranges). Light-emitting diodes (LEDs) could diminish lighting costs as a result of their high efficiency, lower operating temperatures, and wavelength specificity. LEDs can be selected to target the wavelengths used by plants, enabling growers to customize the light produced, to enable maximum plant production and limit wavelengths that do not significantly impact plant growth. In our experiment, hydroponically grown tomato plants (Solanum lycopersicum L.) were grown using a full factorial design with three light intensities (high: 135 μmol·m−2·s−1, medium: 115 μmol·m−2·s−1, and low: 100 μmol·m−2·s−1) at three red (661 nm) to blue (449 nm) ratio levels (5:1, 10:1, and 19:1). Secondary treatments for comparison were 100% HPS, 100% red LED light supplied from above the plant, 100% red LED light supplied below the plant, a 50%:50% LED:HPS mixture, and a control (no supplemental lighting). Both runs of the experiment lasted 120 days during the Summer–Fall 2011 and the Winter–Spring 2011–12. The highest biomass production (excluding fruit) occurred with the 19:1 ratio (red to blue) with increasing intensity resulting in more growth, whereas a higher fruit production was obtained using the 5:1 ratio. The highest marketable fruit production (fruit over 90 g) was obtained with the 50%:50% LED:HPS followed by 5:1 high and 19:1 high. Consistently the 5:1 high performed well in every category. LEDs have been shown to be superior in fruit production over HPS alone, and LEDs can improve tomato fruit production when mixed with HPS. LEDs provide a promising mechanism to enhance greenhouse artificial lighting systems.

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Photosynthetic Efficiency and Anatomical Structure of Pepper Leaf (Capsicum annuum L.) Transplants Grown under High-Pressure Sodium (HPS) and Light-Emitting Diode (LED) Supplementary Lighting Systems

Plants ◽

10.3390/plants10101975 ◽

2021 ◽

Vol 10 (10) ◽

pp. 1975

Author(s):

Anna Sobczak ◽

Marzena Sujkowska-Rybkowska ◽

Janina Gajc-Wolska ◽

Waldemar Kowalczyk ◽

Wojciech Borucki ◽

...

Keyword(s):

High Pressure ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Light Emitting Diodes ◽

Photochemical Efficiency ◽

Photosynthetic Apparatus ◽

Light Emitting ◽

Fluorescence Measurements ◽

Supplemental Lighting ◽

Lighting Systems

The aim of this study was to evaluate the effects of various supplemental greenhouse lighting systems, i.e., high-pressure sodium lamps and mixtures of red and blue light-emitting diodes, on the photochemical efficiency, anatomical leaf structure, and growth of the two pepper cultivars. The intensity levels of the photosynthetically active radiation were the same for both light treatments. In this study, the relative chlorophyll content was measured. Additionally, certain parameters of chlorophyll a fluorescence were measured under ambient light or after dark adaptation. The obtained results showed that the application of light-emitting diodes (LEDs) as supplemental lighting positively affected the anatomical leaf characteristics and plant growth. The leaves of both pepper cultivars were thicker and had larger palisade parenchyma cells under LED supplemental lighting compared to leaves grown under high-pressure sodium (HPS) lamps. Moreover, the mesophyll cells of seedlings grown under LEDs contained more chloroplasts than those growing under HPS lighting. The chlorophyll a fluorescence measurements of pepper seedlings grown under LEDs showed significant increases in photosynthetic apparatus performance index (PI) values compared to plants grown under HPS lamps; however, the values for this index were higher in cv. ‘Aifos’ as compared to cv. ‘Palermo’. We recommend that supplemental lighting systems are applied with caution, as their performance appears to depend not only on the light spectrum but also on the cultivar.

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Comparison of Supplemental Lighting from High-pressure Sodium Lamps and Light-emitting Diodes during Bedding Plant Seedling Production

HortScience ◽

10.21273/hortsci.49.5.589 ◽

2014 ◽

Vol 49 (5) ◽

pp. 589-595 ◽

Cited By ~ 30

Author(s):

Wesley C. Randall ◽

Roberto G. Lopez

Keyword(s):

High Pressure ◽

Light Emitting Diodes ◽

Dry Mass ◽

Operating Life ◽

High Quality ◽

Light Emitting ◽

Northern Latitudes ◽

Bedding Plant ◽

Supplemental Lighting ◽

Plant Seedlings

Annual bedding plant seedlings or plugs are considered high quality when they are compact, fully rooted transplants with a large stem caliper and high root dry mass. Greenhouses in northern latitudes rely on supplemental lighting (SL) from high-pressure sodium lamps (HPS) during winter months to achieve high-quality, finished plugs. Light-emitting diodes (LEDs) offer higher energy efficiencies, a long operating life, and precise waveband specificity that can eliminate wavebands not considered useful. Seedlings of Antirrhinum, Catharanthus, Celosia, Impatiens, Pelargonium, Petunia, Tagetes, Salvia, and Viola were grown at 21 °C under a 16-hour photoperiod of ambient solar light and SL of 100 μmol·m−2·s–1 from either HPS lamps or LED arrays with varying proportions (%) of red:blue light (100:0, 85:15, or 70:30). Height of Catharanthus, Celosia, Impatiens, Petunia, Tagetes, Salvia, and Viola was 31%, 29%, 31%, 55%, 20%, 9%, and 35% shorter, respectively, for seedlings grown under the 85:15 red:blue LEDs compared with those grown under HPS lamps. Additionally, stem caliper of Antirrhinum, Pelargonium, and Tagetes was 16%, 8%, and 13% larger, respectively, for seedlings grown under the 85:15 red:blue LEDs compared with seedlings grown under HPS lamps. The quality index (QI), a quantitative measurement of quality, was similar for Antirrhinum, Catharanthus, Impatiens, Pelargonium, and Tagetes grown under LEDs and HPS lamps. However, it was significantly higher for Petunia, Salvia, and Viola under 85:15, 70:30, and 100:0 red:blue LEDs than under HPS lamps, respectively. These results indicate that seedling quality for the majority of the species tested under SL from LEDs providing both red and blue light was similar or higher than those grown under HPS lamps.

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Cuttings of Impatiens, Pelargonium, and Petunia Propagated under Light-emitting Diodes and High-pressure Sodium Lamps Have Comparable Growth, Morphology, Gas Exchange, and Post-transplant Performance

HortScience ◽

10.21273/hortsci.48.4.428 ◽

2013 ◽

Vol 48 (4) ◽

pp. 428-434 ◽

Cited By ~ 26

Author(s):

Christopher J. Currey ◽

Roberto G. Lopez

Keyword(s):

High Pressure ◽

Gas Exchange ◽

Light Emitting Diodes ◽

Dry Mass ◽

Stem Length ◽

Light Sources ◽

Growth Morphology ◽

Light Emitting ◽

Supplemental Lighting ◽

The Impact

Increasing photosynthetic daily light integral (DLI) by supplementing with high-pressure sodium (HPS) lamps during propagation has been shown to enhance photosynthesis and biomass accumulation of cuttings. The development of high-intensity light-emitting diodes (LEDs) is a promising technology with potential as a greenhouse supplemental lighting source. Our objective was to quantify the impact of narrow spectra supplemental lighting from LEDs on growth, morphology, and gas exchange of cuttings compared with traditional HPS supplemental lighting. Cuttings of Impatiens hawkeri W. Bull ‘Celebrette Frost’, Pelargonium ×hortorum L.H. Bailey ‘Designer Bright Red’, and Petunia ×hybrida Vilm. ‘Suncatcher Midnight Blue’ were received from a commercial propagator and propagated in a glass-glazed greenhouse at 23 °C air and substrate temperature set points. After callusing (≈5 mol·m−2·d−1 for 7 days), cuttings were placed under 70 μmol·m−2·s−1 delivered from HPS lamps or LED arrays with varying proportions (%) of red:blue light (100:0, 85:15, or 70:30). After 14 days under supplemental lighting treatments, growth, morphology, and gas exchange of rooted cuttings were measured. There were no significant differences among Impatiens and Pelargonium cuttings grown under different supplemental light sources. However, compared with cuttings propagated under HPS lamps, stem length of Petunia cuttings grown under 100:0 red:blue LEDs was 11% shorter, whereas leaf dry mass, root dry mass, root mass ratios, and root:shoot ratio of cuttings grown under 70:30 red:blue LEDs were 15%, 36%, 17%, and 24% higher, respectively. Supplemental light source had minimal impact on plants after transplant. Our data suggest that LEDs are suitable replacements for HPS lamps as supplemental light sources during cutting propagation.

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Chemical and Sensory Properties of Greenhouse Tomatoes Remain Unchanged in Response to Red, Blue, and Far Red Supplemental Light from Light-emitting Diodes

HortScience ◽

10.21273/hortsci12469-17 ◽

2017 ◽

Vol 52 (12) ◽

pp. 1734-1741 ◽

Cited By ~ 2

Author(s):

Michael P. Dzakovich ◽

Celina Gómez ◽

Mario G. Ferruzzi ◽

Cary A. Mitchell

Keyword(s):

Secondary Metabolism ◽

Light Emitting Diodes ◽

Tomato Fruit ◽

Red Light ◽

Ascorbic Acid Content ◽

Titratable Acidity ◽

Soluble Solids ◽

Light Emitting ◽

Phytochemical Content ◽

Greenhouse Tomato

In addition to photosynthesis, light is a critical mediator of secondary metabolism in plants, signaling the production of potentially health-promoting phytochemicals and regulating the emission of volatile organic compounds (VOCs) that can alter the sensory perception of a tomato. Light-emitting diodes (LEDs) are a viable way to test the effects of individual wavebands of light and are being quickly adopted by the greenhouse tomato industry. However, studies characterizing the effects of specific wavelengths of light or supplemental lighting on phytochemical content in general are lacking. We hypothesized that enriching the amount of supplemental blue and/or red light that tomatoes receive would positively affect the amount of carotenoids and phenolic compounds that accumulate in tomato fruits through cryptochrome and/or phytochrome-dependent signaling pathways. To test this hypothesis, we compared the chemical and sensory characteristics of tomatoes grown with overhead high-pressure sodium (OH-HPS) lamps to those grown with intracanopy (IC)-LEDs emitting different ratios of red, blue, and far red light. Tomatoes were profiled for total soluble solids, titratable acidity, ascorbic acid content, pH, total phenolics, and prominent flavonoids and carotenoids. Our studies indicated that greenhouse tomato fruit quality was only marginally affected by supplemental light treatments. Moreover, consumer sensory panel data indicated that tomatoes grown under different lighting treatments were comparable across the lighting treatments tested. Our research suggests that the dynamic light environment inherent to greenhouse production systems may nullify the effects of wavelengths of light used in our studies on specific aspects of fruit secondary metabolism.

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Aluminate Red Phosphor in Light-Emitting Diodes: Theoretical Calculations, Charge Varieties, and High-Pressure Luminescence Analysis

ACS Applied Materials & Interfaces ◽

10.1021/acsami.7b06840 ◽

2017 ◽

Vol 9 (28) ◽

pp. 23995-24004 ◽

Cited By ~ 26

Author(s):

Niumiao Zhang ◽

Yi-Ting Tsai ◽

Mu-Huai Fang ◽

Chong-Geng Ma ◽

Agata Lazarowska ◽

...

Keyword(s):

High Pressure ◽

Light Emitting Diodes ◽

Theoretical Calculations ◽

Luminescence Analysis ◽

Red Phosphor ◽

Light Emitting

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Analysis of Environmental Effects on Leaf Temperature under Sunlight, High Pressure Sodium and Light Emitting Diodes

PLoS ONE ◽

10.1371/journal.pone.0138930 ◽

2015 ◽

Vol 10 (10) ◽

pp. e0138930 ◽

Cited By ~ 31

Author(s):

Jacob A. Nelson ◽

Bruce Bugbee

Keyword(s):

High Pressure ◽

Environmental Effects ◽

Light Emitting Diodes ◽

Leaf Temperature ◽

Light Emitting

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Quality, Yield, and Biomass Efficacy of Several Hydroponic Lettuce (Lactuca sativa L.) Cultivars in Response to High Pressure Sodium Lights or Light Emitting Diodes for Greenhouse Supplemental Lighting

Horticulturae ◽

10.3390/horticulturae6010007 ◽

2020 ◽

Vol 6 (1) ◽

pp. 7 ◽

Cited By ~ 2

Author(s):

Erica Hernandez ◽

Michael B. Timmons ◽

Neil S. Mattson

Keyword(s):

High Pressure ◽

Light Emitting Diodes ◽

Phase 1 ◽

Production Cycle ◽

Phase 2 ◽

Fresh Weight ◽

Light Emitting ◽

Cultivar Selection ◽

Led Array ◽

Crop Cycle

Lettuce is an economically important crop that can be grown either in the field or greenhouse. Different challenges are present in either environment; therefore, cultivar selection is important. For hydroponic greenhouse lettuce there is relatively little published information on cultivar selection under different lighting sources. The objective of phase 1 was to determine the influence of lighting using high pressure sodium (HPS) or light emitting diodes (LED) on plant fresh weight, height, tip burn index, bolting, and Brix. Phase 2 was similar to phase 1 but with fewer cultivars (1) to allow for greater number of replicates per treatment per crop cycle. Each experiment consisted of three crop cycles over time per phase. Light sources were controlled using an algorithm, Light and Shade System Implementation (LASSI), to achieve a constant average daily light integral under each treatment and crop cycle. Electrical consumption and efficacy (fresh weight per kWh) from each treatment was estimated using data collected on power consumption from representative lamps multiplied by the number of fixtures and the hours fixtures were on per crop cycle. In phase 1, the fresh weight of 2 to 3 cultivars was greater under HPS and 1 to 2 cultivars under LED, depending on production cycle. The HPS-grown lettuce tended to have more tip burn and bolting in crop cycles 1 and 2, with cycle 3 showing similar tip burn incidence. Bolting was only consistently observed in one cultivar, ‘Teodore’. The LED array used less than half as much electricity as the HPS array, while producing relatively similar size lettuce, therefore, leading to electrical efficacies two- to three-times higher in LED than in HPS treatments. In phase 2, significant differences in height were found in ‘Greenstar’ and ‘Xandra’, with HPS producing larger plants than LED. Significant differences were also found in diameter in ‘Greenstar’, ‘Xandra’, ‘Locarno’, and ‘Crunchita’, with HPS again being larger than LED.

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