scholarly journals Effect of various LED lighting on the growth and development of garden strawberry Fragariaxananassa Duch. and groundcover rose Rosa hybrida L. at greenhouse conditions

2021 ◽  
Vol 935 (1) ◽  
pp. 012046
Author(s):  
P M Evlakov ◽  
A A Bichkov ◽  
T A Grodetskaya ◽  
V Yu Zapletin

Abstract The purpose of this study was to determine the role of various LED (light-emitting diode) light units in ensuring high-quality growth and development of plants, as well as to obtain high-quality seedlings of strawberries and ground cover rose. We studied the physiological reactions of garden strawberry (“Melga” variety) and ground cover rose (“Fairy” variety) plants under controlled conditions and obtained the data on the effect of light quality on plant biological productivity, dynamics of growth processes, photosynthesis rate and transpiration. Regardless of the type of studied crops, the tallest plants were obtained under conditions of supplementary lighting by the lamp with blue/green/red ratio in the spectrum 17/29/54 % (option 1) and the lamp with ratio 18/45/37 % (option 2). At the same time, the dry weight of leaves and roots, as well as the biological productivity of strawberry plants in experimental options 1 and 2 exceeded by 41% than in the control plants (under high pressure sodium lamp). For garden strawberry we recommend the LED in the option 2, for the ground cover rose optimal is the option 1.

2013 ◽  
Vol 22 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Margit Olle ◽  
Akvile Viršile

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.


Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 337 ◽  
Author(s):  
Hao Wei ◽  
Mengzhao Wang ◽  
Byoung Ryong Jeong

Insufficient exposure to light in the winter may result in a longer production periods and lower quality of seedlings in greenhouses for plug growers. Supplementary artificial lighting to plug seedlings may be one solution to this problem. The objective of this study was to assess the effects of the duration of the supplementary light on the growth and development of two watermelon cultivars, ‘Speed’ and ‘Sambok Honey’ grafted onto ‘RS-Dongjanggun’ bottle gourd rootstocks (Lagenaria siceraria Stanld). Seedlings were grown for 10 days in a glasshouse with an average daily natural light intensity of 340 μmol·m−2·s−1 photosynthetic photon flux density (PPFD) and daily supplementary lighting of 8, 12 or 16 h from mixed LEDs (W1R2B1, chip ratio of white:red:blue = 1:2:1) at a light intensity of 100 μmol·m−2·s−1 PPFD, a group without supplementary light was set as the control (CK). The culture environment in a glasshouse had 25/15 °C day/night temperatures, an 85 ± 5% relative humidity, and a natural photoperiod of 8 h. The results showed that all the growth and development parameters of seedlings grown with supplementary light were significantly greater than those without supplementary light (CK). The 12 and 16 h supplementary light resulted in greater growth and development parameters than the 8 h supplementary light did. The same trend was also found with the indexes that reflect the quality of the seedlings, such as the dry weight ratio of the shoot and root, total biomass, dry weight to height ratio of scions, and specific leaf weight. The 12 h and 16 h light supplements resulted in greater Dickson’s quality indexes compared to the 8 h supplementary light, and the 12 h supplementary light showed the greatest use efficiency of the supplementary light. 16 h of daily supplementary light significantly increased the H2O2 content and the antioxidant enzyme activities in seedlings compared to the other treatments. This indicated that 16 h of supplementary light led to certain stresses in watermelon seedlings. In conclusion, considering the energy consumption, 12 h of supplementary light was the most efficient in improving the quality of the two cultivars of grafted watermelon plug seedlings.


2013 ◽  
Vol 448-453 ◽  
pp. 2085-2088
Author(s):  
Xu Jia ◽  
Li Wei Zhu ◽  
Han Jing Cui

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.


2013 ◽  
Vol 291-294 ◽  
pp. 2749-2753 ◽  
Author(s):  
Xin Chen ◽  
Chun Hai Wu ◽  
Xiao Dong Zheng

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.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508e-508
Author(s):  
Bin Liu ◽  
Royal D. Heins

A concept of ratio of radiant to thermal energy (RRT) has been developed to deal with the interactive effect of light and temperature on plant growth and development. This study further confirms that RRT is a useful parameter for plant growth, development, and quality control. Based on greenhouse experiments conducted with 27 treatment combinations of temperature, light, and plant spacing, a model for poinsettia plant growth and development was constructed using the computer program STELLA II. Results from the model simulation with different levels of daily light integral, temperature, and plant spacing showed that the RRT significantly affects leaf unfolding rate when RRT is lower than 0.025 mol/degree-day per plant. Plant dry weight is highly correlated with RRT; it increases linearly as RRT increases.


2012 ◽  
Vol 430-432 ◽  
pp. 1786-1790 ◽  
Author(s):  
Shu Fang Li

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.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  

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.


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