scholarly journals The effects of light-emitting diode lighting on greenhouse plant growth and quality

2013 ◽  
Vol 22 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Margit Olle ◽  
Akvile Viršile
Keyword(s):  
Growth Promotion ◽  
Light Emitting Diode ◽  
Red Light ◽  
Growth Yield ◽  
Sweet Pepper ◽  
Light Sources ◽  
Light Emitting ◽  
Sodium Lamp ◽  
Greenhouse Plant ◽  
High Pressure Sodium Lamp

The aim of this study is to present the light emitting diode (LED) technology for greenhouse plant lighting and to give an overview about LED light effects on photosynthetic indices, growth, yield and nutritional value in green vegetables and tomato, cucumber, sweet pepper transplants. The sole LED lighting, applied in closed growth chambers, as well as combinations of LED wavelengths with conventional light sources, fluorescent and high pressure sodium lamp light, and natural illumination in greenhouses are overviewed. Red and blue light are basal in the lighting spectra for green vegetables and tomato, cucumber, and pepper transplants; far red light, important for photomorphogenetic processes in plants also results in growth promotion. However, theoretically unprofitable spectral parts as green or yellow also have significant physiological effects on investigated plants. Presented results disclose the variability of light spectral effects on different plant species and different physiological indices.

Measurement of Luminance Coefficients of the Road Pavement for Different Lamp Sources

2013 ◽  
Vol 291-294 ◽  
pp. 2749-2753 ◽  
Author(s):  
Xin Chen ◽  
Chun Hai Wu ◽  
Xiao Dong Zheng
Keyword(s):  
Light Emitting Diode ◽  
Wavelength Region ◽  
Light Sources ◽  
Light Emitting ◽  
The Road ◽  
Road Lighting ◽  
Road Pavement ◽  
Average Luminance ◽  
Sodium Lamp ◽  
High Pressure Sodium Lamp

This paper presents the measurement results of the reduced luminance coefficients of an asphalt pavement sample under three common light sources: high pressure sodium lamp (HPS), metal halide lamp (MH), and light-emitting diode (LED), with a specially designed two-dimensional gonioreflectometer. The relative spectral reflectances are obtained with calculation for three different incident angles which indicate light sources with high output in the long wavelength region may be more effective. The measured average luminance coefficient for HPS and MH are 17% larger than that of LED. It means that LED road lamps need higher illuminance than HPS and MH to realize the same brightness for road lighting.

scholarly journals Supplementary Far-Red Light Did Not Affect Tomato Plant Growth or Yield under Mediterranean Greenhouse Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1849
Author(s):  
Onofrio Davide Palmitessa ◽  
Beniamino Leoni ◽  
Francesco Fabiano Montesano ◽  
Francesco Serio ◽  
Angelo Signore ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Plant Growth ◽  
Fruit Quality ◽  
Light Emitting Diode ◽  
Red Light ◽  
Growth Yield ◽  
Fruit Production ◽  
F1 Hybrid ◽  
Light Emitting ◽  
Red Radiation

In the Mediterranean region, tomato plants are often cultivated in two short cycles per year to avoid the heat of summer and the low solar radiation of winter. Supplementary light (SL) makes it possible to cultivate during the dark season. In this experiment, a tomato F1 hybrid cultivar DRW7723 was cultivated in a greenhouse for a fall-winter cycle. After transplant, light emitting diode (LED) interlighting, with two light spectra (red + blue vs. red + blue + far-red) was applied as SL. Plant growth, yield, gas exchange, nutrient solution (NS) consumption, and fruit quality were analyzed. In general, the effects of adding far-red radiation were not visible on the parameters analyzed, although the yield was 27% higher in plants grown with SL than those grown without. Tomatoes had the same average fresh weight between SL treatments, but the plants grown with SL produced 16% more fruits than control. Fruit quality, gas exchange and NS uptake were not influenced by the addition of far-red light. Interlighting is, therefore, a valid technique to increase fruit production in winter but at our latitude the effects of adding far-red radiation are mitigated by available sunlight.

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

HortScience ◽  
2017 ◽  
Vol 52 (2) ◽  
pp. 236-244 ◽  
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.

PHOTOTHERAPY FOR MILD TO MODERATE ACNE VULGARIS WITH PORTABLE BLUE AND RED LED

2011 ◽  
Vol 04 (01) ◽  
pp. 45-52 ◽  
Author(s):  
GUANGDA LIU ◽  
CHANGE PAN ◽  
KAI LI ◽  
YUAN TAN ◽  
XUNBIN WEI
Keyword(s):  
Side Effects ◽  
Light Emitting Diode ◽  
Acne Vulgaris ◽  
Red Light ◽  
Light Sources ◽  
Light Emitting ◽  
Led Light ◽  
Led Phototherapy ◽  
Red Led ◽  
Complete Treatment

In this paper, we studied portable blue and red light-emitting-diode (LED) light sources in phototherapy for mild to moderate acne vulgaris to evaluate the efficacy and tolerance of patients. Patients, randomly divided into blue and red groups, received either blue or red LED phototherapy twice a week for four weeks. After complete treatment, the number of lesions reduced by 71.4% in the blue group, in contrast to 19.5% in the red group. No obvious side effects were observed during and one month after the treatment, except for some mild dryness mentioned by several patients.

Lamps and Lanterns Analysis in Highway Illumination System

2013 ◽  
Vol 448-453 ◽  
pp. 2085-2088
Author(s):  
Xu Jia ◽  
Li Wei Zhu ◽  
Han Jing Cui
Keyword(s):  
High Pressure ◽  
Technology Development ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Illumination System ◽  
Sodium Lamp ◽  
High Pressure Sodium Lamp

Nowadays the main highway illumination facilities are HPSL (high pressure sodium lamp). With the technology development of LED (light emitting diode), it is used for highway lighting become possible gradually. This paper compared features of HPSL and LED, meanwhile give a deep discussion.

scholarly journals Quantification of Spectral Perception of Plants with Light Absorption of Photoreceptors

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 556
Author(s):  
Woo Hyun Kang ◽  
Jaewoo Kim ◽  
Hyo In Yoon ◽  
Jung Eek Son
Keyword(s):  
Light Absorption ◽  
Light Quality ◽  
Solar Spectrum ◽  
Plant Responses ◽  
Light Sources ◽  
Light Emitting ◽  
Artificial Lighting ◽  
Visual Color ◽  
Sodium Lamp ◽  
High Pressure Sodium Lamp

Although plant responses to artificial lighting spectra often produce abnormal morphogenesis and reduced productivity, no quantification method to determine how plants perceive and respond to light has been available. Our objective in this study was to test whether a plant’s spectral perception can be quantified using the light absorption of its major photoreceptors, phytochrome, cryptochrome, and phototropin. We developed an artificial solar lamp and three different light sources, based on a high-pressure sodium lamp, a fluorescent lamp, and red and blue light-emitting diodes, whose absorption by photoreceptors was equal to that of the standard solar spectrum. Cucumber plants grown under the artificial solar and developed light sources showed normal photomorphogenesis and were indistinguishable from each other. Plants grown under unmodified commercial light sources had abnormal photomorphogenesis that made them short and small. The photosynthetic rate was higher under the unmodified light sources; however, dry masses were highest under the artificial solar and modified light sources, indicating that the cucumber plants are optimized to the solar spectrum. Our results clearly demonstrate that the spectral perceptions of plants can be quantified using the light absorption of their photoreceptors, not visual color or spectra. We expect that our findings will contribute to a better understanding of plant perceptions of and responses to light quality, and improve the productivity of plants cultivated under artificial light.

The Research on the Application of Two Kinds of Light Sources in the Training Venue for Physical Education of Universities

2012 ◽  
Vol 430-432 ◽  
pp. 1786-1790 ◽  
Author(s):  
Shu Fang Li
Keyword(s):  
Energy Efficiency ◽  
High Pressure ◽  
Physical Education ◽  
Lighting Design ◽  
Light Sources ◽  
Metal Halide Lamp ◽  
Sodium Lamp ◽  
Electric Light ◽  
High Pressure Sodium Lamp ◽  
Power And Energy

The energy efficiency experiment of electric light is implemented according to the lighting design of the physical training venues. In the experiment, the corresponding illumination, power and energy efficiency ratio of the commonly used high pressure sodium lamp and metal halide lamp which work under the voltage ranging from 187V to 234V are experimentally measured and the lighting effect characteristics of the two kinds of electric light sources compared, proving that the high pressure sodium light source should be employed in the training venue for physical education of universities.

scholarly journals Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Trioctylphosphine Oxide ◽  
Optical And Electrical Properties ◽  
Colloidal Solutions ◽  
High Quality ◽  
Light Emitting ◽  
Hot Injection ◽  
Color Conversion

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

Sign in / Sign up

Export Citation Format

Share Document