scholarly journals Application of Led on Plant Growth Unit in Tomato Cultivation

2021 ◽  
Vol 50 (3) ◽  
pp. 523-529
Author(s):  
Ramazan ŞEnol ◽  
Semra Kiliç ◽  
Kubi̇lay Taşdelen
Keyword(s):  
Plant Growth ◽  
Pulse Width Modulation ◽  
Light Emitting Diode ◽  
Plant Morphology ◽  
Growth Unit ◽  
Special Role ◽  
Light Emitting ◽  
Total Chlorophyll Content ◽  
System A ◽  
Mode 2

Effects of Light Emitting Diode (LED) lamps on plant growth with different modulations on the tomato plant were investigated by applying under actual conditions in the greenhouses. Thus, four different pulse width modulation (PWM) systems from red and blue LEDS at different wavelengths were designed. Trials were performed by using direct current (Mode1), 5Khz-φ = 0o (Mode2), 5Khz-φ = 180o (Mode3) and 1Khz-φ = 0o (Mode4) and the tomato grown under the sun at the same conditions were compared for controlling purposes. Stomata movements and total chlorophyll content of the tomatoes were examined, and the results were compared to the tomatoes that were grown under sun. The custom developed artificial four light source system, a treatment of Mode 2 produced the highest yield, while each treatment played its special role in regulating plant morphology and physiology. Bangladesh J. Bot. 50(3): 523-529, 2021 (September)

scholarly journals Application of Light-emitting Diodes and the Effect of Light Quality on Horticultural Crops: A Review

HortScience ◽  
2019 ◽  
Vol 54 (10) ◽  
pp. 1656-1661 ◽  
Author(s):  
Liang Zheng ◽  
Huaming He ◽  
Weitang Song
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Light Quality ◽  
Light Emitting Diode ◽  
Spectral Composition ◽  
Plant Morphology ◽  
Plant Growth And Development ◽  
Light Emitting ◽  
Horticultural Crops ◽  
Physiology And Biochemistry

Plant growth and development relies on light and is influenced by light. Light-emitting diode (LED) technology is nowadays providing the possibility for regulating plant growth and development by modifying light spectral composition. Many researches have been carried out to figure out the effects of light quality on various aspects of plant behaviors, including plant morphology, physiology, and biochemistry. In this review, we summarized those research outputs, in order to give suggestion of light quality application for both research and production purposes, in the field of productional yield, productional quality for horticultural plants including vegetables or ornamentals in difference with cultivation goals.

A High Efficiency Step-Up WLED Driver with Wide Range PWM Dimming

2012 ◽  
Vol 588-589 ◽  
pp. 884-887
Author(s):  
Fei Xu ◽  
Le Nian He
Keyword(s):  
Pulse Width Modulation ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
System Efficiency ◽  
Current Sensing ◽  
Light Emitting ◽  
Wide Range ◽  
Simulation Results ◽  
Peak Value ◽  
Pwm Dimming

A high efficiency step-up White Light Emitting-diode (WLED) driver with PWM dimming is presented in this paper. An integrated current sensing technique is used to improve system efficiency. Meanwhile, a novel PWM(pulse width modulation) dimming scheme is proposed to achieve wide range dimming frequency, which can be adaptive to dimming frequency from 200Hz to 200 KHz. The proposed driver is designed with CSMC 0.5um 40V bipolar-CMOS-DMOS process. Simulation results verify the functionality of the design and high efficiency is realized, with a peak value of 94.12% at 5.5V-input and 200mA-load.

scholarly journals Effect of the Spectral Quality and Intensity of Light-emitting Diodes on Several Horticultural Crops

HortScience ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 268-271 ◽  
Author(s):  
Miguel Urrestarazu ◽  
Cinthia Nájera ◽  
María del Mar Gea
Keyword(s):  
Plant Growth ◽  
Light Emitting Diode ◽  
Photon Flux ◽  
Photosynthetic Response ◽  
Light Spectrum ◽  
Light Emitting ◽  
Artificial Lighting ◽  
Horticultural Crops ◽  
Distribution Study ◽  
Environment Chamber

Light-emitting diode (LED) lamps signify one of the most important advances in artificial lighting for horticulture over the last few decades. The objective of this study was to compare the cultivation of four horticultural plants using a conventional white LED tube (T0) light against one with a good spectral fit to the maximum photosynthetic response (T1) at two intensities. The experiment was carried out with two types of young lettuce, tomato, and bell pepper plants. In a controlled environment chamber, six and four lamps per square meter were used to achieve high (H) and low (L) intensity, respectively. We measured the lighting parameters illuminance (lux) and photosynthetic photon flux (PPF) intensity (µmol·m−2·s−1). The dry and fresh weight, leaf area (LA), and specific index were measured to gauge plant growth. The photosynthetic activity and energy efficiency (EE) were recorded for each species over 60 days of cultivation. The results clearly demonstrate that, compared with conventional LED lamps, the specific horticultural LED lamps with an improved light spectrum increased the EE of the evaluated vegetables by 26%. At both the studied light intensities, plant growth was clearly more closely linked to the spectral fit of the light to the maximum photosynthetic response recorded by McCree (1972) than to PPF or illuminance (lux). We therefore suggest that a specific, detailed spectral distribution study be conducted to predict the effect of the specific quantity and quality of light used in this study on a single parameter of plant growth.

Change of circadian effect with colour temperature and eye spectral transmittance at different ages

2020 ◽  
pp. 147715352092337 ◽  
Author(s):  
HJ Tian ◽  
T Chen ◽  
Y Hu ◽  
T Guan ◽  
MP Cai
Keyword(s):  
Pulse Width Modulation ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Age Groups ◽  
Spectral Transmittance ◽  
Potential Health ◽  
Light Emitting ◽  
Colour Temperature ◽  
Age Related ◽  
Circadian Effect

With the recent advances in photobiology research and light-emitting diode technology, considering the circadian effects and the potential health benefits of lighting has attracted much attention. In this work, to achieve a white light-emitting LED cluster with beneficial and tunable circadian effects, a red-green-blue-warm white colour-mixing method based on pulse width modulation has been introduced and developed. Five optimal spectral power distributions were achieved with the correlated colour temperatures of 2700, 4000, 5000, 6500 and 8000 K that provide maximum colour-rendering indices of 95.0, 96.6, 96.8, 95.6 and 93.5 for each correlated colour temperature. Moreover, the Bellia model was modified to take into account the reduction in spectral transmittance of the human eye that occurs with age. Using the five spectral power distributions, based on the eye spectral transmittance with age-related change, we studied the change of the circadian effect with corneal illuminance at the different correlated colour temperatures. Solutions are provided for scenarios where circadian effect should be avoided for different age groups while the reasonable illuminance and colour temperature are maintained.

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 The Effect of Plant Growth Compensation by Adding Silicon-Containing Fertilizer under Light Stress Conditions

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1287
Author(s):  
Natalya A. Semenova ◽  
Alexandr A. Smirnov ◽  
Andrey A. Grishin ◽  
Roman Y. Pishchalnikov ◽  
Denis D. Chesalin ◽  
...  
Keyword(s):  
Plant Growth ◽  
Nutrient Solution ◽  
Negative Impact ◽  
Light Emitting Diode ◽  
Light Stress ◽  
Growth Period ◽  
Positive Influence ◽  
Biologically Active ◽  
Light Emitting ◽  
Growing Period

The effects of different spectral compositions of light-emitting diode (LED) sources and fertilizer containing biologically active silicon (Si) in the nutrient solution on morphological and physiological plant response were studied. Qualitative indicators and the productivity of plants of a red-leaved and a green-leaved lettuce were estimated. Lettuce was grown applying low-volume hydroponics in closed artificial agroecosystems. The positive effect of Si fertilizer used as a microadditive in the nutrient solution on the freshly harvested biomass was established on the thirtieth day of vegetation under LEDs. Increase in productivity of the red-leaved lettuce for freshly harvested biomass was 26.6%, while for the green-leaved lettuce no loss of dry matter was observed. However, being grown under sodium lamps, a negative impact of Si fertilizer on productivity of both types of plants was observed: the amount of harvested biomass decreased by 22.6% and 30.3% for the green- and red-leaved lettuces, respectively. The effect of using Si fertilizer dramatically changed during the total growing period: up to the fifteenth day of cultivation, a sharp inhibition of the growth of both types of lettuce was observed; then, by the thirtieth day of LED lighting, Si fertilizer showed a stress-protective effect and had a positive influence on the plants. However, by the period of ripening there was no effect of using the fertilizer. Therefore, we can conclude that the use of Si fertilizers is preferable only when LED irradiation is applied throughout the active plant growth period.

An Intelligent Personas System for Determining LED Lighting Design Requirements

2011 ◽  
Vol 145 ◽  
pp. 43-47
Author(s):  
Kevin C. Tseng ◽  
Chi Wei Chung
Keyword(s):  
Light Emitting Diode ◽  
Lighting Design ◽  
Development Stage ◽  
Design Team ◽  
Light Emitting ◽  
System A ◽  
Novel Approach ◽  
Design Requirements ◽  
Market Trends ◽  
Effective Design

The intent of this paper is to illustrate a personas system effective design to aid development of new products. This system would help a design team find and understand the lifestyle of target customers by using personas method in early concept development stage. In order to quickly realize market trends, easily collect customer requirements and readily integrate user opinions, the proposed system is capable of helping experts in different domains concurrently share their ideas in real time and discuss with each other without geographic limitation. In addition, a novel approach is proposed, named as ‘Personas Matrix’, to quantify the requirements which can accelerate the assessment of true needs. Finally, in order to validate the proposed system, a LED (Light-Emitting Diode) project was applied to test the functionality of the approach and the usefulness of the system thus helping the design team refine requirements, simplify requirement gathering, and prompt the assessment.

scholarly journals Supplemental LED lighting increases pansy growth

2015 ◽  
Vol 33 (4) ◽  
pp. 428-433
Author(s):  
Nezihe Koksal ◽  
Meral Incesu ◽  
Ahmet Teke
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Plant Biomass ◽  
Light Emitting Diode ◽  
Low Light ◽  
Light Emitting ◽  
Led Lighting ◽  
Light Levels ◽  
Long Day ◽  
Number Of Branches

ABSTRACT: Pansy (Viola cornuta) is a facultative long-day plant that flowers from October until March in Turkey. During the winter months, low light levels can limit plant growth and development. Light emitting diodes (LEDs) can provide supplemental lighting in greenhouses which produce same light intensity with less energy than conventional incandescent lighting. Light emitting diode technologies have enabled affordable and efficient light systems to be installed in greenhouses and plastic tunnels in the field. In this experiment we evaluated the effects of supplemental red-orange LED lightening on the growth and development of pansy cv. Blue Blotch grown in plastic tunnels. The energy, which LEDs are to consume, was provided through a solar panel system with the aim of drawing attention to the cleanliness of solar energy source. Five hours of supplement LED lighting was applied after dusk starting from November to February. Pansy growth and development parameters were compared with non-light supplied control plants. Supplemental LED lighting significantly increased plant biomass weight, flower number and leaves number at the rate of 52%, 72%, and 47%, respectively. Moreover, LED lighting increased plant growth rate (0.109 and 0.306 g of fresh weight), compared with the no light control. LED lighting, however, had no effect on length of stems, number of branches and the diameter of flowers. Thus, this study indicated that pansies are light limited during the winter months and supplemental LED lighting can significantly increase pansy growth and development.

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