Illumination In Greenhouse Research Articles

Ce[formula omitted][formula omitted] Cr3＋ energy transfer in Y[formula omitted]Al[formula omitted]MgSiO12 garnet host and application in horticultural lighting

In this study, the photoluminescence properties of Y3Al3MgSiO12:Cr3＋ (YMASG:Cr3＋) and Y3Al3MgSiO12: 2%Ce3+, Cr3＋ (YMASG:2%Ce3+, Cr3＋) were investigated, and the energy transfer from Ce3+ to Cr3＋ were examined. All phosphor samples were prepared by the aqueous sol–gel method. The phase purity and surface morphology of the obtained sample was evaluated using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). To determine the photoluminescence (PL) properties of YMASG:Cr3＋ and YMASG:2%Ce3+, Cr3＋, emission and excitation spectra along with reflection spectra were recorded. PL decay measurements were also performed, and PL lifetime values were determined. It was found that Ce3+ → Cr3＋ energy transfer efficiency increases with increasing Cr3＋ concentration. To investigate the temperature-dependent emission of YMASG:Cr3＋ and YMASG:2%Ce3+, Cr3＋, PL emission, and PL decay measurements were conducted in a temperature range from 77 to 500 K. Temperature-dependent PL decay measurements also revealed that the Cr3＋ ions mainly cause thermal quenching of YMASG:2%Cfe3+, 1%Cr3＋ emission. To check the suitability of synthesized materials to be applied for greenhouse illumination, two pcLEDs containing YMASG:Cr3＋ and YMASG:Ce3+, Cr3＋ phosphors were constructed. PcLED prototypes applicability for efficient horticulture lighting was also investigated within this study.

基于高动态范围成像的温室番茄植株图像色彩矫正方法

In this paper, aiming at the need of stable access to visual information of intelligent management of greenhouse tomatoes, the color correction method of tomato plant image based on high dynamic range imaging technology was studied, in order to overcome the objective limitation of complex natural lighting conditions on the stable color presentation of working objects. In view of the color distortion caused by the temporal and spatial fluctuation of illumination in greenhouse and sudden change of radiation intensity in complex background, a calibration method of camera radiation response model based on multi-exposure intensity images is proposed. The fusion effect of multi band image is evaluated by field test. The results show that after multi band image fusion processing, the brightness difference between the recognized target and other near color background is significantly enhanced, and the brightness fluctuation of the background is suppressed. The color correction method was verified by field experiments, and the gray information, discrete degree and clarity of tomato plant images in different scenes and periods were improved.

Light and Temperature Control for Greenhouse Plant Growth

Introduction. The article deals with the conditions for growing greenhouse plants. Supplementary lighting supports the process of plant photosynthesis and the microclimate in the greenhouse. The authors suggest the ways to reduce energy consumption in greenhouses by controlling the microclimate and process of supplementary lighting in greenhouses. Materials and Methods. Special lighting and temperature are required for growing greenhouse plants. A method of efficient plant growing is light and temperature control. The development of a control algorithm requires the mathematical models that relate the process of photosynthesis to the microclimate parameters. There are given the mathematical models based on the experimental data. Results. The control system and algorithm to control plant-growing conditions have been developed to maintain the greenhouse microclimate. LED lamps are used to control the lighting process. The authors present the developed block diagram of the control system, which contains four channels responsible for the main energy-intensive microclimate factors. The description of the algorithm of the greenhouse light-temperature control is given. Discussion and Conclusion. In conclusion, the need to maintain the greenhouse microclimate and supplementary lighting with the different radiation spectrum for the efficient cultivation of greenhouse plants is shown. The developed structure and control algorithm for the supplementary plant lighting process and greenhouse illumination through using LED lamps help reduce energy consumption.

Effects of alien substitutions of chromosomes of homoeologous group 7 on the heading time of wheat–barley substitution lines (Triticum aestivum L. – Hordeum marinum ssp. gussoneanum 4x Hudson)

The effects of alien substitutions of chromosomes on the heading time of ditelosomic (DT) wheat–barley substitution lines in which the chromosome 7HLmar from Hordeum marinum ssp. gussoneanum 4x replaced the chromosomes 7A, 7B and 7D of common wheat were studied. The plants were grown under short and long day illumination in greenhouse and in the field. The lines studied were found to differ in response to the length of the day. Under short day conditions, DT7HLmar(7B) and DT7HLmar(7A) showed an increase in the period before heading. In this case, the substitution effect of chromosome 7B was more significant than the effect of chromosome 7A. Under these conditions, the substitution of chromosome 7D did not have a significant effect on the heading time. Under long day conditions in the greenhouse and under natural conditions of a long day in the Novosibirsk region, substitution lines came into ear earlier than under a short day conditions and did not differ in the heading time. Allele-specific primers established the allelic composition of the genes Vrn-A1, Vrn-B1, Vrn-D1 and Vrn-B3 in ditelosomic lines. It was shown that the two DT7HLmar(7A) and DT7HLmar(7D) lines have the same genotype -VRN-A1b/VRN-B1c/vrn-D1/ vrn-B3 and that the DT7HLmar(7B) line has the genotype -VRN-A1a/VRN-B1c/vrn-D1. The results show that regardless of the genotype for the Vrn genes, the wheat-barley substitution lines react to the change in the photoperiod, especially in the absence of chromosomes 7B and 7A.

Relation between Changes in Photosynthetic Rate and Changes in Canopy Level Chlorophyll Fluorescence Generated by Light Excitation of Different Led Colours in Various Background Light

Using light emitting diodes (LEDs) for greenhouse illumination enables the use of automatic control, since both light quality and quantity can be tuned. Potential candidate signals when using biological feedback for light optimisation are steady-state chlorophyll a fluorescence gains at 740 nm, defined as the difference in steady-state fluorescence at 740 nm divided by the difference in incident light quanta caused by (a small) excitation of different LED colours. In this study, experiments were conducted under various background light (quality and quantity) to evaluate if these fluorescence gains change relative to each other. The light regimes investigated were intensities in the range 160–1000 μ mol m − 2 s − 1 , and a spectral distribution ranging from 50% to 100% red light. No significant changes in the mutual relation of the fluorescence gains for the investigated LED colours (400, 420, 450, 530, 630 and 660 nm), could be observed when the background light quality was changed. However, changes were noticed as function of light quantity. When passing the photosynthesis saturate intensity level, no further changes in the mutual fluorescence gains could be observed.

Results of Experimental Research on Computerized Intellectual Monitoring Means of Effective Greenhouse Illumination

Abstract Industrial greenhouses are complex technological facilities where control and managing of the cultivation regimes affecting the efficiency of evapotranspiration and photosynthesis should be provided. The paper solves the relevant scientific and applied problem of evaluating and analyzing the metrological and functional characteristics of effective illumination sensors. The subject of the research is the metrological characteristics of means of metrical monitoring of effective illumination in the visible optical range for protected horticulture. The object of the study is the processes and factors which affect the metrological characteristics of the serial low-cost sensors of effective illumination in the visible optical range. The findings presented in this paper focus on solving the relevant scientific and applied problem of limited results of experiments on serial low-cost sensors of effective illumination in the visible optical range and their subsequent mathematical analysis to evaluate metrological characteristics. Promising areas of the research on the metrological provision of modern computerized systems for monitoring and controlling the effective illumination of industrial greenhouses are justified. The research results can be integrated into modern methods and means of computerized metrical monitoring and automatic control of technological regimes of greenhouse cultivation.

Illumination in Greenhouse and Plant Growth

Illumination in Greenhouse and Plant Growth

METABOLIC ACTIVITIES OF ROOTS AND THEIR BEARING ON THE RELATION OF UPWARD MOVEMENT OF SALTS AND WATER IN PLANTS

THE RELATION of water absorption and transpiration to the'absorption and movement of salt in the plant has been a subject of discussion since an early period in the study of plant physiology. Various divergent views have been expressed. From some researches, the evidence seems to lead to the idea that the absorption and upward movement of salt are often largely independent of the movement of water; while from other researches it would appear that increased transpiration results in enhanced salt' absorption-several recent articles report data interpreted in this way (Schmidt, 1936; Freeland, 1937; Wright, 1939; Phillis and Mason, 1940). Evidence by earlier investigators has been reviewed in the monograph by Curtis (1935). Apparently, most workers have not experimentally studied the role of metabolic factors in salt absorption and upward movement. Previous publications from this laboratory (Hoagland, 1936; Hoagland and Broyer, 1936; Prevot and Steward, 1936; Hoagland, 1940) presented detailed evidence on the absorption and accumulation of salt by excised root systems of the young barley plant. This evidence clearly established the point that the initial process of salt absorption by uninjured roots is not dependent on water absorption and transpiration. We now desire to discuss a series of experiments on intact young barley plants which illustrate the importance of the relations of root metabolism to the upward movement of salt as well as to its absorption and accumulation in root cells of excised roots. The whole subject of salt absorption and movement has many ramifications, and the present paper deals only with a section of the phenomena involved, although it is believed that a point of view is outlined which has general significance. RESULTS.-The first experiment (fig. 1) had for its objective a comparison of the amounts of salt absorbed and transported by metabolically active young barley plants (initially high in sugar and low in salt content) under two extremes of conditions affecting water absorption and transpiration (a) in the dark in a highly humid atmosphere,2 (b) in the light (normal greenhouse illumination) with rapid movement of air produced by an electric fan. The culture media in both cases were controlled at 250C. The duration of the experimental period was twelve hours. Under both conditions of the aerial environment, salt (KBr) was rapidly absorbed, and