scholarly journals Effect of Light Emitting Diode (LED) Spectra on Plant Growth

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Nur Syahirah Talib ◽  
Diyana Jamaludin ◽  
Nur Sakinah Abdul Malek
Keyword(s):  
Chlorophyll Content ◽  
Growth And Development ◽  
Control Treatment ◽  
White Led ◽  
Hydroponic System ◽  
Light Emitting ◽  
White Leds ◽  
Red Led ◽  
Lettuce Growth ◽  
Number Of Leaves

The effect of lights generated by red, blue and white light emitting diodes (LED) on growth and development of lettuce were investigated and compared with lettuce without supplemental lighting. A vertical multi-tier hydroponic system was used to grow lettuce. Each tier consisted of 60 heads of lettuce with different LED colour and one tier without LED was used as control. The following measurements on plant physiology were taken: number, length and chlorophyll content of leaves, height and weight of plants. Based on number of leaves, red LED shows the highest number of leaves compared to lettuce under blue, white and control treatment. The similar trend also can be found in the lengths of leaves which shows the highest length produce under red LED.  Red LED also produce highest weight of lettuce by 28% as compared to white LED. White LED improved lettuce growth development in the height by 13% and amount of chlorophyll content. Lettuce grown under blue LED shows lowest growth and development compared to lettuce grown under red and white LEDs based on parameters above, and lettuce without LED were died within 2 weeks.  This result indicated that the red LED was the most effective spectra in growth response of lettuce plants. This study also demonstrates the effectiveness of LED in improving lettuce growth on vertical multi-tier hydroponic system.

Growth and Light Properties of Fluorescent SiC for White LEDs

2012 ◽  
Vol 717-720 ◽  
pp. 87-92
Author(s):  
Mikael Syväjärvi ◽  
Rositza Yakimova ◽  
Motoaki Iwaya ◽  
Tetsuya Takeuchi ◽  
Isamu Akasaki ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
White Light ◽  
Energy Savings ◽  
Red Light ◽  
Visible Range ◽  
White Led ◽  
Light Emitting ◽  
Blue Led ◽  
White Leds ◽  
New Type

The LED technology started to developed many years ago with red light emitting diodes. To achieve the blue LED, novel growth technologies and process steps were explored, and made it possible to demonstrate efficient blue LED performance from nitrides. The efficiency was further developed and blue LEDs were commercially introduced in the 1990’s. The white LED became possible by the use of the blue LED and a phosphor that converts a part of the blue light to other colors in the visible range to combine into white light. However, even today there are limitations in the phosphor-based white LED technology, in particular for general lighting, and new solutions should be explored to speed the pace when white LEDs will be able to make substantial energy savings. In this paper we overview gallium nitride materials evolution and growth concepts for LEDs. We describe the fluorescent silicon carbide material prepared by a novel growth technology for a new type of white LED in general lighting with pure white light. This paper introduces an interesting research in fundamental growth and optical properties of light emitting silicon carbide.

Fundamentals and Applications of Red Light-Emitting Diodes (LEDs) In Vitro Plant Growth on Tomato Lycopersicon esculentum Mill

2019 ◽  
Vol 805 ◽  
pp. 141-145
Author(s):  
Nguyen Phuc Thien
Keyword(s):  
Lycopersicon Esculentum ◽  
Plant Growth ◽  
Significant Influence ◽  
Growth And Development ◽  
Red Light ◽  
Light Emitting ◽  
Red Led ◽  
In Vitro Plant ◽  
Normal Light

The aim of these studies was mainly to investigate the effects of monochromatic LEDs applied singly on the in vitro plant growth and morphogenesis. Various morphological and physiological parameters are considered that influence the growth and development of plants in vitro under red LED light as compared to those under normal light. Upon exposure to LED, in vitro-raised plants have shown significant improvements in growth and morphogenesis. In particular, red and blue lights, either alone or in combination, have a significant influence on plant growth. The present study gives an overview of the fundamentals of LEDs and describes their effects on in vitro plant growth and morphogenesis and their future potentials. The main objective of this study was to carry out line and combing ability of plant growth on tomato.

Syntheses, crystal structures and photoluminescence properties of Ca9Y(PO4)5(SiO4)F1.5O0.25:Ln3+ (Ln3+ = Eu3+/Tb3+/Dy3+/Sm3+) phosphors for near-UV white LEDs

RSC Advances ◽  
2016 ◽  
Vol 6 (95) ◽  
pp. 92371-92377 ◽  
Author(s):  
Man Liu ◽  
Wei Lü ◽  
Jiansheng Huo ◽  
Baiqi Shao ◽  
Yang Feng ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Red Light ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
White Leds ◽  
Red Led

We report red light-emitting Ca9Y(PO4)5(SiO4)F1.5O0.25:Eu3+/Sm3+ phosphors for the fabrication of red LED devices.

scholarly journals Agronomic and sensory evaluation of lettuce in hydroponic system

2021 ◽  
Vol 37 ◽  
pp. e37074
Author(s):  
Jean Jefferson de Sá ◽  
Carolina Medeiros Vicentini-Polette ◽  
Marta Regina Verruma-Bernardi ◽  
Marta Helena Fillet Spoto ◽  
Fernando César Sala
Keyword(s):  
Chlorophyll Content ◽  
Direct Relationship ◽  
Shoot Length ◽  
Fresh Mass ◽  
Stem Length ◽  
Hydroponic System ◽  
Green Color ◽  
Instrumental Color ◽  
Commercial Cultivars ◽  
Number Of Leaves

Lettuce is the most important leafy vegetable in Brazil. Hydroponic lettuce cultivation has grown due to the viability of harvesting throughout the year. In this context, this study aimed to evaluate the agronomic characteristics, color, and preference of curly lettuce in the NFT hydroponic system. Six lineages (6601-1A, 6601-2L, 7016-6A, 7119-1B, 7223-1A, and 7224-4A) and two commercial cultivars (Brida and Vanda) of lettuce were used, in a completely randomized blocks design with four replications. Shoot length, root length, stem length, number of leaves, stem diameter, plant diameter, shoot fresh mass, root fresh mass, chlorophyll content, instrumental color, and sensory characteristics were evaluated. As for agronomic evaluation, the bolting of 6601-2L lettuce was relevant in different attributes. The Vanda lettuce and the lineage 7016-6A presented best performances for shoot fresh mass (399.44 and 378.63 g, respectively), while the lineages 7119-1B and 6601-2L present the worst performance (279.50 and 273.13 g, respectively). There was variation in chlorophyll content and luminosity, however, the evaluators did not notice differences between lettuces for brightness or green color, as well as for crunchy texture. Lettuces 6601-2L, 7224-4A, 6601-1A, Brida, 7223-1A, and 7119-1B were preferred. The variation among plants may be due to different situations, such as harvesting times and bolting, and a direct relationship between agronomic properties and preference among lettuces has not been established yet.

scholarly journals The Growth and Development of Sweet Basil (Ocimum basilicum) and Bush Basil (Ocimum minimum) Grown under Three Light Regimes in a Controlled Environment

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 743 ◽  
Author(s):  
Aldarkazali ◽  
Rihan ◽  
Carne ◽  
Fuller
Keyword(s):  
Plant Growth ◽  
Radiant Heat ◽  
Oil Yield ◽  
Light Sources ◽  
White Led ◽  
Light Emitting ◽  
Sweet Basil ◽  
Light Regimes ◽  
Led Array ◽  
Red Led

Light is a crucial element for plant growth and production. In areas where natural light is not sufficient for optimal plant growth and production, high pressure sodium (HPS) light sources are widely used. However, HPS lamps are considered not very electrically efficient generating 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). The effects of three lighting sources (White LED, Blue/Red LED and HPS) on the growth, development and on the essential oil yield and quality of sweet basil and bush basil were investigated. There was a clear advantage to the Blue/Red (452 nm and 632 nm, respectively) LED on virtually all growth and physiological parameters measured for both basil species. The HPS lighting system always performed least effectively in all comparisons. Combining increases in plant yield and increases in oil yield the Blue/Red LED array outperformed the HPS lights by a factor of approximately double, with the white LED being intermediate between these two extremes.

Color-tunable Al6Si2O13:Eu2+,Mn2+ phosphor with high color rendering index based on energy transfer for warm white LEDs

2018 ◽  
Vol 42 (18) ◽  
pp. 15207-15214 ◽  
Author(s):  
Bo Yan ◽  
Gui-Gen Wang ◽  
Long-Fei Liu ◽  
Xin-Zhong Wang ◽  
You-Xiao Chen ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
White Led ◽  
Light Emitting ◽  
White Leds ◽  
Warm White Light ◽  
Color Tunable ◽  
Color Rendering Index ◽  
Color Rendering

A type of warm-white-light-emitting Al6Si2O13:Eu2+,Mn2+ phosphor with high color rendering index was synthesized for UV-excited white LED.

scholarly journals Fractional Contributions of Defect-Originated Photoluminescence from CuInS2/ZnS Coreshells for Hybrid White LEDs

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Quinton Rice ◽  
Sangram Raut ◽  
Rahul Chib ◽  
Zygmunt Gryczynski ◽  
Ignacy Gryczynski ◽  
...  
Keyword(s):  
Thermal Quenching ◽  
Defect State ◽  
White Led ◽  
Time Resolved ◽  
Light Emitting ◽  
White Leds ◽  
Slow Decay ◽  
Interface Defect ◽  
Donor Acceptor ◽  
White Light Emitting Diodes

The wide optical tunability and broad spectral distribution of CuInS2/ZnS (CIS/ZnS) coreshells are key elements for developing the hybrid white light emitting diodes where the nanoparticles are stacked on the blue LEDs. TwoCIS/ZnS555 nmandCIS/ZnS665 nmcoreshells are utilized for the hybrid white LED development. The time-resolved spectroscopy ofCIS/ZnS555 nmandCIS/ZnS665 nmreveals the correlation between the fast, intermediate, and slow decay components and the interface-trapped state and shallow- and deep-trapped states, although the fractional amplitudes of photoluminescence (PL) decay components are widely distributed throughout the entire spectra. The temperature-resolved spectroscopy explains that the PL from deep-trapped donor-acceptor (DA) state has relatively large thermal quenching, due to the relative Coulomb interaction of DA pairs, compared to the thermal quenching of PL from interface defect state and shallow-trapped DA state. A good spectral coupling between the blue diode excitation and the PL from CIS/ZnS leads to the realization of hybrid white LEDs.

scholarly journals Allelopathic potential aqueous extract of tubers of tiririca in the growth and development of lettuce

2020 ◽  
Vol 13 (4) ◽  
pp. 65
Author(s):  
D. O. Souza ◽  
R. Agustini ◽  
G. S. Romero ◽  
P.E. S. Rueda ◽  
V. C. Galati
Keyword(s):  
Chlorophyll Content ◽  
Aqueous Extract ◽  
Growth And Development ◽  
Fresh Mass ◽  
Allelopathic Effect ◽  
Root Extract ◽  
Allelopathic Potential ◽  
High Productivity ◽  
Number Of Leaves ◽  
Root Size

Lettuce (Lactuca sativa) belongs to the asteraceae family, known worldwide and appreciated for generations. Due to the great acceptance, the lettuce is a vegetable of high consumption. In search of solutions for high productivity some techniques have been researched to reduce the stress suffered by the plant to the environment. This study aimed to verify that the aqueous extract of tiririca, in different strengths, present some allelopathic effect on the development of the lettuce. The use of the aqueous extract, which has in its composition the Indole Acetic Acid-AIA (Auxin), was used by capillary irrigation, with the following treatments: T0-control; T1- 25% of concentration; T2- 50% of concentration; T3- 100% of concentration. This study consisted of five replicates and five plants per treatment, with a total of 100 plants. The design was completely randomized. The analyzes were root size, shoot development by fresh mass plant, number of leaves and chlorophyll content. According to the data, it was observed that the concentration of the 100% root extract resulted in higher values of root development, however, affected shoot growth, a result verified in the fresh mass, in which the plants presented reduced weight when compared to the other treatments, and consequently affected the amount of leaves produced by the plants submitted to this treatment, the chlorophyll content was also lower for the plants treated with the maximum concentration of the extract. Therefore, it can be concluded that high dosages of the tiririca extract had an allelopathic effect inhibiting the growth and development of the lettuce plants, and did not present a satisfactory result.

scholarly journals The effects of LED light spectrum manipulation on growth and color performance of giant gourami Osphronemus gouramy Lacepede Padang strain

2022 ◽  
Vol 21 (1) ◽  
pp. 11-21
Author(s):  
Bambang Kusmayadi Gunawan ◽  
Kukuh Nirmala ◽  
Dinar Tri Soelistyowati ◽  
Daniel Djokosetiyanto ◽  
Wildan Nurussalam
Keyword(s):  
Light Emitting Diode ◽  
Emission Spectra ◽  
Control Treatment ◽  
Light Spectrum ◽  
Light Emitting ◽  
Blue Led ◽  
Pectoral Fins ◽  
Randomized Design ◽  
Red Led ◽  
Effect Of Light

This study aimed to evaluate the effect of light spectrum on growth and color performance of giant giant gourami Padang strain. The experiment used a completely randomized design (RAL) with four light emitting diode (LED) treatments in  different emission spectra (white, red, green, and blue) at 550 Lux intensity, compared to the control treatment (light room with white tubular lamp at 50 Lux intensity). The irradiation was carried out for 12 hours of photoperiod. The fish used had the total length of 82.90±4.2 mm and body weight of 9.87 ± 0.99 g. The highest growth performance was found in blue LED treatment with the specific growth rate of  2.73 ± 0.2% and feed efficiency of 86.26 ± 2.71%. The best color performance was found in red LED treatment with the RGB ratio of 44.57 ± 0.62% in dorsal fin, 38.41 ± 1.36% in pectoral fins, and 45.33 ± 2.25% in anal fin with the chromatophore cell concentration at 1.973±58 cells/mm2.   Keywords : Osphronemus gouramy, blue LED, spectrum, chromatophore, light   ABSTRAK   Penelitian ini bertujuan untuk mengevaluasi pengaruh spektrum cahaya terhadap kinerja pertumbuhan dan warna ikan gurami strain Padang. Rancangan penelitian yang digunakan adalah rancangan acak lengkap (RAL) dengan 4 perlakuan cahaya lampu light emitting diodes (LED)  yang memiliki spektrum panjang gelombang berbeda (putih, merah, hijau dan biru) intensitas 550 Lux dan kontrol (cahaya ruang berasal dari lampu tubular putih intensitas 50 Lux). Penyinaran dilakukan selama 12 jam mengikuti fotoperiod. Ikan uji yang digunakan memiliki panjang total 82,90 ± 4,2 mm, dengan bobot 9,87 ± 0,99 g. Kinerja pertumbuhan terbaik terdapat pada perlakuan LED biru dengan laju pertumbuhan spesifik sebesar 2,73 ± 0,2% dan efisiensi pakan sebesar 86,26 ± 2,71%. Performa warna terbaik terdapat pada perlakuan LED merah dengan rasio warna merah pada RGB bagian dorsal sebesar 44,57 ± 0,62%, sirip pektoral sebesar 38,41 ± 1,36%, dan sirip anal sebesar 45,33 ±  2,25% dengan jumlah sel kromatofor sebanyak 1973 sel/mm2.   Kata kunci : Osphronemus gouramy, LED biru, spektrum, kromatofor, cahaya        

scholarly journals Spectral Effects of Three Types of White Light-emitting Diodes on Plant Growth and Development: Absolute versus Relative Amounts of Blue Light

HortScience ◽  
2013 ◽  
Vol 48 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Kevin R. Cope ◽  
Bruce Bugbee
Keyword(s):  
Plant Growth ◽  
Blue Light ◽  
Plant Development ◽  
Growth And Development ◽  
Stem Elongation ◽  
Leaf Expansion ◽  
Light Sources ◽  
Plant Growth And Development ◽  
Light Emitting ◽  
White Leds

Light-emitting diodes (LEDs) are a rapidly developing technology for plant growth lighting and have become a powerful tool for understanding the spectral effects of light on plants. Several studies have shown that some blue light is necessary for normal growth and development, but the effects of blue light appear to be species-dependent and may interact with other wavelengths of light as well as photosynthetic photon flux (PPF). We report the photobiological effects of three types of white LEDs (warm, neutral, and cool, with 11%, 19%, and 28% blue light, respectively) on the growth and development of radish, soybean, and wheat. All species were grown at two PPFs (200 and 500 μmol·m−2·s−1) under each LED type, which facilitated testing the effect of absolute (μmol photons per m−2·s−1) and relative (percent of total PPF) blue light on plant development. Root and shoot environmental conditions other than light quality were uniformly maintained among six chambers (three lamp types × two PPFs). All LEDs had similar phytochrome photoequilibria and red:far red ratios. Blue light did not affect total dry weight (DW) in any species but significantly altered plant development. Overall, the low blue light from warm white LEDs increased stem elongation and leaf expansion, whereas the high blue light from cool white LEDs resulted in more compact plants. For radish and soybean, absolute blue light was a better predictor of stem elongation than relative blue light, but relative blue light better predicted leaf area. Absolute blue light better predicted the percent leaf DW in radish and soybean and percent tiller DW in wheat. The largest percentage differences among light sources occurred in low light (200 μmol·m−2·s−1). These results confirm and extend the results of other studies indicating that light quantity and quality interact to determine plant morphology. The optimal amount of blue light likely changes with plant age because plant communities balance the need for rapid leaf expansion, which is necessary to maximize radiation capture, with prevention of excessive stem elongation. A thorough understanding of this interaction is essential to the development of light sources for optimal plant growth and development.

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