Performance of Broilers Reared under Monochromatic Light Emitting Diode Supplemental Lighting

Electric supplemental lighting can account for a significant proportion of total greenhouse energy costs. Thus, the objectives of this study were to compare high-wire tomato (Solanum lycopersicum) production with and without supplemental lighting and to evaluate two different lighting positions + light sources [traditional high-pressure sodium (HPS) overhead lighting (OHL) lamps vs. light-emitting diode (LED) intracanopy lighting (ICL) towers] on several production and energy-consumption parameters for two commercial tomato cultivars. Results indicated that regardless of the lighting position + source, supplemental lighting induced early fruit production and increased node number, fruit number (FN), and total fruit fresh weight (FW) for both cultivars compared with unsupplemented controls for a winter-to-summer production period. Furthermore, no productivity differences were measured between the two supplemental lighting treatments. The energy-consumption metrics indicated that the electrical conversion efficiency for light-emitting intracanopy lighting (LED-ICL) into fruit biomass was 75% higher than that for HPS-OHL. Thus, the lighting cost per average fruit grown under the HPS-OHL lamps was 403% more than that of using LED-ICL towers. Although no increase in yield was measured using LED-ICL, significant energy savings for lighting occurred without compromising fruit yield.

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Upward LED Lighting from the Base Suppresses Senescence of Lower Leaves and Promotes Flowering in Indoor Rose Management

HortScience ◽

10.21273/hortsci15795-21 ◽

2021 ◽

pp. 1-7

Author(s):

Namiko Yamori ◽

Yoriko Matsushima ◽

Wataru Yamori

Keyword(s):

Leaf Senescence ◽

Light Emitting Diode ◽

Plant Management ◽

Indoor Environments ◽

Flower Buds ◽

Flower Bud ◽

Light Emitting ◽

Led Lighting ◽

Dim Light ◽

Supplemental Lighting

In indoor environments such as hotels, the light intensity is generally insufficient for managing plants, and flower buds often fail to open. Lamps placed above (downward lighting) take up space. We assessed the applicability of lighting from underneath (upward lighting) for the indoor management of roses. We grew plants indoors in dim light for 2 weeks under three conditions: 1) without supplemental lighting, 2) with downward light-emitting diode (LED) lighting, and 3) with LED lighting. We quantified photosynthetic components (chlorophyll and rubisco) and the maximum quantum yield of photosystem II (Fv/Fm, an indicator of plant health) to determine the effects of each treatment on the quality and photosynthetic abilities of the leaves. We determined the ratios of dead and opened flower buds to elucidate the effects of supplemental lighting on flower bud maturation. Management without supplemental lighting decreased the number of flowers and resulted in lower-leaf senescence. Downward LED lighting promoted blooming but also resulted in lower-leaf senescence. However, upward LED lighting promoted blooming and maintained the photosynthetic abilities of the leaves, including the lower leaves. This study shows a strong case for using upward LED lighting in appropriate settings for indoor plant management and LED-based horticulture.

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Effect of Monochromatic Light Emitting Diode on the Growth of Four Microalgae Species (Chlorella vulgaris, Nitzschia sp., Phaeodactylum

Journal of the Korean Society of Marine Environment and Safety ◽

10.7837/kosomes.2015.21.1.001 ◽

2015 ◽

Vol 21 (1) ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Seok-Jin Oh ◽

◽

Hyeong-Kyu Kwon ◽

Jin-Young Jeon ◽

Han-Seob Yang

Keyword(s):

Chlorella Vulgaris ◽

Light Emitting Diode ◽

Monochromatic Light ◽

Light Emitting

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Microcavity‐Enhanced Blue Organic Light‐Emitting Diode for High‐Quality Monochromatic Light Source with Nonquarterwave Structural Design

Advanced Optical Materials ◽

10.1002/adom.201901421 ◽

2020 ◽

Vol 8 (7) ◽

pp. 1901421 ◽

Cited By ~ 1

Author(s):

Jie Lin ◽

Yongsheng Hu ◽

Xingyuan Liu

Keyword(s):

Light Source ◽

Structural Design ◽

Light Emitting Diode ◽

Monochromatic Light ◽

High Quality ◽

Light Emitting ◽

Organic Light Emitting Diode ◽

Organic Light ◽

Monochromatic Light Source

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Geranium and Purple Fountain Grass Leaf Pigmentation Is Influenced by End-of-Production Supplemental Lighting with Red and Blue Light-emitting Diodes

HortScience ◽

10.21273/hortsci11098-16 ◽

2017 ◽

Vol 52 (2) ◽

pp. 236-244 ◽

Cited By ~ 3

Author(s):

W. Garrett Owen ◽

Roberto G. Lopez

Keyword(s):

Chlorophyll Content ◽

Light Emitting Diode ◽

Red Light ◽

Light Sources ◽

Low Light ◽

Light Emitting ◽

Pennisetum Setaceum ◽

Hue Angle ◽

Supplemental Lighting ◽

Relative Chlorophyll Content

Under low-light greenhouse conditions, anthocyanin pigmentation in vegetative tissues of red- or purple-leafed floricultural crops is not fully expressed and, consequently, plants are not as visually appealing to consumers. Our objective was to quantify the effect of end-of-production (EOP; before shipping) supplemental lighting (SL) of different light sources, qualities, and intensities on foliage color of geranium (Pelargonium ×hortorum L.H. Bailey ‘Black Velvet’) and purple fountain grass [Pennisetum ×advena Wipff and Veldkamp (formerly known as Pennisetum setaceum Forsk. Chiov. ‘Rubrum’)]. Plants were finished under early (Expt. 1) and late (Expt. 2) seasonal greenhouse ambient solar light and provided with 16 hours of day-extension lighting from low-intensity light-emitting diode (LED) lamps [7:11:33:49 blue:green:red:far-red light ratio (%); control] delivering 4.5 μmol·m−2·s−1, or 16 hours of EOP SL from high-pressure sodium (HPS) lamps delivering 70 μmol·m−2·s−1, or LED arrays (100:0, 87:13, 50:50, or 0:100 red:blue) delivering 100 μmol·m−2·s−1, or 0:100 red:blue LEDs delivering 25 or 50 μmol·m−2·s−1. Geranium and fountain grass chlorophyll content and leaf color were estimated using a SPAD-502 chlorophyll meter and Minolta tristimulus colorimeter, respectively. Relative chlorophyll content (RCC) and foliage L* (lightness), C* (chroma; a measure of saturation), and h° (hue angle; a measure of tone) values were significantly influenced by EOP SL and days of exposure. Generally, RCC of geranium and fountain grass increased from 3 to 14 days of exposure to EOP SL from HPS lamps and LEDs delivering 100 μmol·m−2·s−1. Under low daily light integrals (DLIs) [8.6 mol·m−2·d−1 (geranium) and 9.4 mol·m−2·d−1 (purple fountain grass)] EOP SL providing 100 μmol·m−2·s−1 of 100:0, 87:13, 50:50, or 0:100 red:blue light for ≥14 days resulted in lower L* (darker foliage), C* (saturated), and h° (orange to violet-red hues). Our data indicate that a minimum of 14 days of EOP SL providing 100 μmol·m−2·s−1 of 50:50 or 0:100 red:blue light enhanced foliage color of geranium and fountain grass leaves when plants were grown under a low greenhouse DLI ≤ 9 mol·m−2·d−1.

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Growth and Photosynthetic Efficiency of Two Lettuce Cultivars Under Light–Emitting Diode Monochromatic Light

Journal of the Faculty of Agriculture, Kyushu University ◽

10.5109/4363546 ◽

2021 ◽

Vol 66 (1) ◽

pp. 11-20

Author(s):

Chun–Yu TSAI ◽

Yung–Fu YEN ◽

Chyung AY ◽

Ikuo MIYAJIMA ◽

Kuang–Liang HUANG

Keyword(s):

Photosynthetic Efficiency ◽

Light Emitting Diode ◽

Monochromatic Light ◽

Light Emitting

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An Adaptive Control Approach for Light-emitting Diode Lights Can Reduce the Energy Costs of Supplemental Lighting in Greenhouses

HortScience ◽

10.21273/hortsci11385-16 ◽

2017 ◽

Vol 52 (1) ◽

pp. 72-77 ◽

Cited By ~ 10

Author(s):

Marc W. van Iersel ◽

David Gianino

Keyword(s):

Duty Cycle ◽

Light Emitting Diode ◽

Production Costs ◽

Photon Flux ◽

Substantial Part ◽

Response Curves ◽

Light Emitting ◽

Full Power ◽

Supplemental Lighting ◽

Led Lights

Supplemental lighting in greenhouses is often needed for year-round production of high-quality crops. However, the electricity needed for supplemental lighting can account for a substantial part of overall production costs. Our objective was to develop more efficient control methods for supplemental lighting, taking advantage of the dimmability of light-emitting diode (LED) grow lights. We compared 14 hours per day of full power supplemental LED lighting to two other treatments: 1) turning the LEDs on, at full power, only when the ambient photosynthetic photon flux (PPF) dropped below a specific threshold, and 2) adjusting the duty cycle of the LEDs so that the LED lights provided only enough supplemental PPF to reach a preset threshold PPF. This threshold PPF was adjusted daily from 50 to 250 μmol·m−2·s−1. Turning the LED lights on at full power and off based on a PPF threshold was not practical since this at times resulted in the lights going on and off frequently. Adjusting the duty cycle of the LED lights based on PPF measurements underneath the light bar provided excellent control of PPF, with 5-minute averages typically being within 0.2 μmol·m−2·s−1 of the threshold PPF. Continuously adjusting the duty cycle of the LED lights reduced electricity use by 20% to 92%, depending on the PPF threshold and daily light integral (DLI) from sunlight. Simulations based on net photosynthesis (An) − PPF response curves indicated that there are large differences among species in how efficiently supplemental PPF stimulates An. When there is little or no sunlight, An of Heuchera americana is expected to increase more than that of Campanula portenschlagiana when a low level of supplemental light is provided. Conversely, when ambient PPF >200 μmol·m−2·s−1, supplemental lighting will have little impact on An of H. americana, but can still results in significant increases in An of C. portenschlagiana (1.7 to 6.1 μmol·m−2·s−1 as supplemental PPF increases from 50 to 250 μmol·m−2·s−1). Adjusting the duty cycle of the LEDs based on PPF levels assures that supplemental light is provided when plants can use that supplemental light most efficiently. Implementing automated duty cycle control of LED grow lights is simple and low cost. This approach can increase the cost effectiveness of supplemental lighting, because of the associated energy savings.

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Effect of various monochromatic light-emitting diode colours on the behaviour and welfare of broiler chickens

Canadian Journal of Animal Science ◽

10.1139/cjas-2018-0242 ◽

2020 ◽

Vol 100 (4) ◽

pp. 615-623

Author(s):

Shabiha Sultana ◽

Md. Rakibul Hassan ◽

Byung Soo Kim ◽

Kyeong Seon Ryu

Keyword(s):

Broiler Chickens ◽

Light Emitting Diode ◽

Monochromatic Light ◽

Growth Period ◽

Broiler Chicks ◽

Light Emitting ◽

Gait Score ◽

Set Up ◽

Effect Of Light ◽

Sitting Behaviour

This study was conducted to evaluate the effect of different monochromatic light-emitting diode colours on the behaviour and welfare of broiler chicks. A total of 750 one-day-old chicks were used and lighting was set up as follows: pure blue (PB, 440–450 nm), bright blue (460–470 nm), sky blue (480–490 nm), greenish blue (500–510 nm), and green (530–540), while fluorescent white (400–700 nm) was used as a control. Birds were placed into 30 independent light proof pens and each light treatment was replicated five times with 25 birds in each pen. Video was recorded and behaviour was evaluated twice per day and observed five consecutive days in a week. Broiler welfare was evaluated using the characteristics of gait score, tibia dyschondroplasia, tonic immobility duration, and heterophil:lymphocyte ratio. In results, sitting, walking, and ground pecking behaviour were influenced by the light colour from 0 to 7 d. Extending the rearing period from 8 to 21 d resulted in increased sitting behaviour and decreased walking and pecking behaviour in chicks in the PB treatment (P < 0.05). When the growth period was extended further (22–42 d), sitting behaviour increased when chicks were exposed to PB light (P < 0.05). The effect of light colour did not significantly influence welfare of broiler chicks. Thus, the present results suggest that PB light colour decreased broiler chickens movement and thus increased duration of sitting behaviour. These results would be helpful to choose light colour for broiler producers.

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