LEDs

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Growing blackberries more energy-efficient with LED lighting

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Submitted by Elsewhere on 2020-Dec-04 Fri 13:33

Woody small fruit (such as blackberry and raspberry) is increasingly being grown in a tunnel or a greenhouse. This makes it easier to control the crop. Moreover, heavy rain showers, for example, cause much less damage. The Greenhouse Horticulture and Flower Bulbs Business Unit of Wageningen University &…

What is the difference between Red/Blue vs. broad spectrum LEDs

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Submitted by Elsewhere on 2020-Dec-03 Thu 14:50

Growers generally have two options when it comes to horticultural LED spectrums – “full spectrum” or “broad-spectrum”, which appears white light; and “red/blue spectrum”, which can appear as purple or pink light.    The red/blue spectrum LED luminaires are often referred to as narrow band spectrum lights – because the…

CAN (ON): Cucumber grower continues through winter with LED interlighting

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Submitted by Elsewhere on 2020-Dec-02 Wed 13:23

Albuna Farms has chosen to install Philips GreenPower LED interlighting to grow lights in its greenhouse in Ruthven, Ontario. During the first phase of the project, Philips GreenPower LED interlighting grow lights will be installed on 4.7 hectares in their greenhouse. Albuna Farms expects the new system…

📄 How much energy can LEDs really save in greenhouses?

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Submitted by Elsewhere on 2020-Nov-24 Tue 12:23

When switching to LEDs, your electricity bill will lower and your heating bill will increase. Sounds fair, and most growers are completely aware of this. But by how much? That's often unclear, even when the LEDs have already been installed. "Since electricity is measured in kwH and gas is measured in…

📄 The Comparison of Constant and Dynamic Red and Blue Light Irradiation Effects on Red and Green Leaf Lettuce

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Submitted by Elsewhere on 2020-Nov-16 Mon 19:27

In this study, we sought to evaluate and compare the effects of constant and dynamic lighting on red and green leaf lettuce (Lactuca sativa L. Red Cos and Lobjoits Green cos) cultivated in a controlled environment. Plants were illuminated with the combination of red 662 and 638 nm, blue 452 nm, and far-red 737 nm at 16 h photoperiod and constant daily light integral (DLI) of each component. Five constant or dynamic lighting treatments were performed: (BR) constant flux of both B452 and R662; (B*R) constant flux of R662, but the DLI of B452 condensed in 8 h in the middle of photoperiod doubling the PPFD of blue light; (BR*) constant flux of B452, but the DLI of R662 light condensed in the middle of photoperiod; (BdynR) constant flux of R662, but the flux of B452 varies in the sinusoidal profile during 16 h photoperiod, imitating diurnal increase and decrease in lighting intensity; and (BRdyn) constant flux of B452, but the flux of R662 varies in sinusoidal profile. The lettuce’s response to dynamic lighting strategies was cultivar specific. Dynamic lighting strategies, mimicking natural lighting fluctuations, did not have a remarkable effect on photosynthesis and antioxidative parameters, but the dynamic flux of blue light component had a pronounced effect on higher macro and microelement contents in lettuce leaves.

Growers can reuse dissapated heat from the water cooled LED fixtures

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Submitted by Elsewhere on 2020-Nov-13 Fri 10:59

When temperatures are dropping, growers can reuse dissapated heat from the water cooled LED fixtures to heat the ponds and therefor make full use of the energy consumption of the LED fixtures. #ledlightgrow #ledgrowlight #greenhouse #teeltvijvers #hydroponicgreenhouse #basil pic.twitter.com/MiGqH0Zpv3

"LED fixtures have to fit seamlessly with the grower’s existing situation and new requirements"

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Submitted by Elsewhere on 2020-Nov-09 Mon 13:29

Growers have a wide range of different business and cultivation goals, meaning that every grow light solution is unique. "LED grow light is increasingly used in existing greenhouses, so the LED fixtures have to fit seamlessly with the grower’s existing situation and new requirements. For this reason we…

Reproducing sunlight in controlled laboratory environments

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Submitted by Elsewhere on 2020-Nov-06 Fri 11:03

Plants and more generally, photosynthetic organisms need light to live. Exposed to artificial light, plants implement adaptation processes. All these adaptation strategies are studied in agronomic research and plant biology laboratories, in particular at CEA Cadarache, within the Institut de Biosciences…

Increasing growth of lettuce and mizuna under sole-source LED lighting

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Submitted by Elsewhere on 2020-Oct-30 Fri 13:13

Light recommendations for horticultural crops often focus on the optimal daily light integral (DLI) without regard to how that light is delivered throughout each day. Because photosynthesis is more efficient at lower photosynthetic photon flux density (PPFD), we hypothesized that longer photoperiods with…

Growth and Nutrient Element Content of Hydroponic Lettuce are Modified by LED Continuous Lighting of Different Intensities and Spectral Qualities

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Submitted by Elsewhere on 2020-Oct-29 Thu 12:55

LED red (R) and blue (B) continuous light (CL) is a potential efficient way to increaseplant productivity of plant factory with artificial light (PFAL), but limited information wasexplored about their effects on plant mineral nutrition. In an environmentally controlled plantfactory with artificial light (PFAL), the effects of CL of different intensities and spectral qualities,emitted by R and B LEDs on growth and nutrient element content and accumulation of lettuce(Lactuca sativa L.), were conducted in three hydroponic experiments. Two treatments, normal light(12 h/12 h) and CL (24 h/0 h) in experiment 1, three CL intensities (100, 200 and 300 μmol∙m−2∙s−1) inexperiment 2, and three CL light qualities (1R:3B, 1R:1B and 3R:1B) in experiment 3 weredesigned. The results showed that CL significantly increased the fresh and dry lettuce shootbiomass compared with normal light, and shoot fresh and dry biomass increased with theintensity increment of CL. In experiment 3, shoot fresh biomass was great under high R lightproportion CL treatment, while dry shoot biomass remained unchanged. Both CL and CL withincreased intensities promoted shoot C content and accumulation in lettuce. CL reduced N, P, K,Ca, Mg, Cu and Zn contents in lettuce shoot, while Fe and Mn contents did not change comparedto NL. Moreover, CL increased Ca, Fe and Mn accumulation. 100–200 μmol∙m−2∙s−1 CL facilitatedN, P, Ca, Mg, Fe, Mn, Cu and Zn contents in shoot, but K content was not influenced comparedwith 300μmol∙m−2∙s−1. The data showed that high B light ratio (75%) facilitated C contentcomparison with low B ratios (50% and 25%). However, lettuce grown under 3R1B treatment hadthe higher C accumulation. Shoot N, P, K, Ca, Mg, Fe, Mn and Zn contents were higher under1R1B treatment, and Cu content did not affected by light quality. Moreover, accumulation of N, P,K, Ca, Mg, Fe, Mn, Zn and Cu in shoot was higher under 1R1B treatment, while P, Ca, Mg, Mnaccumulation under 3R1B treatment was the lowest. In conclusion, CL tends to reduce shootmineral element contents due to dilution effect as shoot dry weight increases compared to NL.However, long‐term (12 days) CL composed of 1R1B, 100–200 μmol∙m−2∙s−1 tends to obtain relativehigher K, Ca, Fe and Zn contents in the greater dry lettuce shoot.

Increasing Growth of Lettuce and Mizuna under Sole-Source LED Lighting Using Longer Photoperiods with the Same Daily Light Integral

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Submitted by Elsewhere on 2020-Oct-28 Wed 07:53

Light recommendations for horticultural crops often focus on the optimal daily light integral (DLI) without regard to how that light is delivered throughout each day. Because photosynthesis is more efficient at lower photosynthetic photon flux density (PPFD), we hypothesized that longer photoperiods with lower PPFD results in faster growth than shorter photoperiods with higher PPFD and the same DLI. We quantified the effect of different photoperiods, all providing the same DLI, on photosynthesis and growth of two leafy greens. Mizuna (Brassica rapa var. japonica) and lettuce (Lactuca sativa) “Little Gem” were grown from seed in a controlled environment chamber (20 °C and 819 µmol·mol−1 CO2) under six photoperiods (10, 12, 14, 16, 18, and 20 h). LED fixtures provided white light and PPFD was adjusted so each treatment received a DLI of 16 mol·m−2·d−1. Mizuna and lettuce were harvested 30 and 41 days after planting, respectively. Longer photoperiods with lower PPFD increased light interception, chlorophyll content index, quantum yield of photosystem II, and aboveground biomass, but decreased instantaneous CO2 assimilation of lettuce and mizuna. Aboveground biomass increased 16.0% in lettuce and 18.7% in mizuna in response to increasing the photoperiod from 10 to 20 h. In summary, extending the photoperiod and lowering PPFD increases growth of lettuce and mizuna by increasing light interception and the quantum yield of photosystem II.

LED lighting helps Canadian vertical farm to increase food production all year round

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Submitted by Elsewhere on 2020-Oct-16 Fri 13:52

GoodLeaf Community Farms in Canada selected Signify to equip its new state-of-the-art farm with Philips Horticulture LED lighting. As a branded producer, GoodLeaf grows and packs fresh, nutritious, and pesticide-free micro and baby greens year-round. The company operates a 4,000-square-metre indoor vertical farm in Guelph, Ontario, which is now fully operational to supply some of the largest Canadian retail chains. GoodLeaf is backed by McCain Foods as its strategic investor.

In high-wire cultivation, it's important that the light penetrates deep into the crop

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Submitted by Elsewhere on 2020-Oct-06 Tue 12:35

Many growers who invest in LED lighting opt for wide-beam LED fixtures with a high light output. In this way, they aim to achieve optimal light distribution at the top of the crop and to limit investment costs. In high-wire crops, however, it is particularly important that the light penetrates deep into…

'Our LED advice is given on the basis of scientific knowledge'

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Submitted by Elsewhere on 2020-Oct-05 Mon 13:32

Making cultivation results measurable with the aim of creating certainty of results when switching to LED. That is the starting point of the new collaboration between Ledgnd and B-Mex. “By structurally registering crop results in our portal, the effect of LED can be measured and the added value of this…

Using LED grow lights and less irrigation makes stronger plants

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Submitted by Elsewhere on 2020-Sep-30 Wed 15:46

Hort Americas is currently working on a germination and propagation project of leafy greens and culinary herbs. The project is in collaboration with their demonstration greenhouse partners, The State Fair of Texas and the Big Tex Urban Farms. Big Tex Urban farms provide the labor needed to grow […]

CAN (ON): Pepper grower to implement smart LED lighting

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Submitted by Elsewhere on 2020-Sep-30 Wed 09:30

Starting in November, Sollum Technologies’ smart LED lighting solution will be implemented at Allegro Acres, a family-owned greenhouse pepper farm operating in Southwestern Ontario for over 20 years. Their 30-acre production capacity makes them one of the major greenhouse producers in the province.…

"Water cooling improves the lifespan of the entire LED fixture"

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Submitted by Elsewhere on 2020-Sep-30 Wed 09:29

Since the introduction of LED fixture 'Monarch' earlier this year, Oreon has been able to illuminate many projects with this high power 1000W LED grow light. This LED fixture has been specially designed to replace a 1000W HPS fixture in the greenhouse 1 on 1 (using the same cabling).  More than six months later,…

Using LED grow lights and less irrigation makes stronger plants

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Submitted by Elsewhere on 2020-Sep-29 Tue 09:40

Hort Americas is currently working on a germination and propagation project of leafy greens and culinary herbs. The project is in collaboration with their demonstration greenhouse partners, The State Fair of Texas and the Big Tex Urban Farms. Big Tex Urban farms provide the labor needed to grow and…

End-Of-Day LED Lightings Influence the Leaf Color, Growth and Phytochemicals in Two Cultivars of Lettuce

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Submitted by Elsewhere on 2020-Sep-26 Sat 15:00

Four light treatments (W: white light; EOD-B: end-of-day enhanced blue light; EOD-FR: end-of-day supplementary far-red light; EOD-UV: end-of-day supplementary ultraviolet-A light) were designed to explore the effects of end-of-day (EOD) lightings (30 min before dark period) on leaf color, biomass and phytochemicals accumulation in two lettuce cultivars (Lactuca sativa cv. ‘Red butter’ and ‘Green butter’) in artificial light plant factory. EOD-FR stimulated the plant and shoot biomass of two cultivars, and EOD-B suppressed the growth of ‘Red butter’ but induced higher biomass in ‘Green butter’. EOD lightings generated brighter, greener and yellower leaf in ‘Red butter’ at harvest, but the highest lightness and the deepest redness of ‘Green butter’ leaf were observed in the middle growth stage. ‘Red butter’ had prominent higher contents of chlorophylls and carotenoids, while these pigments showed less sensitivity to the interaction of cultivars and EOD lightings. EOD lightings impeded the accumulation of anthocyanin in two cultivars, except EOD-UV slightly increased the anthocyanin contents in ‘Green butter’. EOD-UV strengthened the antioxidant capability of ‘Green butter’, but EOD lightings had different effects on the antioxidant and nutritional compound contents in two lettuce cultivars.

 

What's the difference between broad full spectrum LEDs and red/blue LEDs?

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Submitted by Elsewhere on 2020-Sep-23 Wed 13:18

Growers generally have two options when it comes to horticultural LED spectrums – “full spectrum or broad-spectrum, which appears as white light; and red/blue spectrum, which can appear as purple or pink light.    

The red/blue spectrum LED luminaires are often referred to as narrow band spectrum lights – because the wavelengths they emit are within a narrow band of light.   LED luminaires that emit a “white” light are often referred to as “broad spectrum” or “full spectrum” lights because they include a broad band of the light spectrum (more similar to the sun) which renders a “white” light (there are no true white wavelengths).   

It should be noted that essentially all “white” LEDs are blue LEDs that are coated in a phosphor that converts the blue light into longer wavelengths. The phosphor absorbs the blue light and re-emits some or most of the photons into green and red light.  This coating reduces the efficiency of the LED in converting photons into usable PAR (photosynthetically active radiation) light, but makes for a better work environment in sole source applications. The composition of the phosphor coating will help to determine the spectral quality of the white light emitted. To find the efficacy of your luminaire, you will need to divide the Photosynthetic Photon Flux (PPF) of the luminaireby its input wattage.  The resulting efficacy value, will be represented in μmol/J.  The higher the number, the more efficient the luminaire is at converting electrical energy into photons of PAR.   

Basil production in horizontal or vertical aquaponic systems

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Submitted by Elsewhere on 2020-Sep-21 Mon 09:58

Aquaponic facilities allow the joint production of fish and plants in a reduced space. This hydroponic technique, combined with vertical farming, is not well studied. The main objective of a recent work was to compare basil production between horizontal and vertical decoupled aquaponic systems and assess…

Comparative Analysis of Horizontal and Vertical Decoupled Aquaponic Systems for Basil Production and Effect of Light Supplementation by LED

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Submitted by Elsewhere on 2020-Sep-17 Thu 09:15

Aquaponic facilities allow the joint production of fish and plants in a reduced space. This hydroponic technique, combined with vertical farming, is not well studied. The main objective of this work was to compare basil production between horizontal and vertical decoupled aquaponic systems and assess the utilization of supplemental lighting in a greenhouse environment. Six independent vertical racks were arranged with hydroponic trays at three heights. Three racks were affixed with LED lighting on the lowest levels and three with supplemental lighting on the intermediate level. Immediately adjacent to the vertical systems, two independent horizontal systems containing three trays were constructed to compare basil production. After 35 days of growth post transplanting, the total production per tray and weight, height, number of leaves, and nodes of 20 selected plants per tray were determined. Records of the intensity of illumination photosynthetic photon flux density (PPFD)) were recorded at dawn (8:00), noon (12:00), and dusk (18:00) at randomly predetermined positions associated with the 20 selected plants per tray. The total basil production in the experiment was 58.79 kg, with an average production per unit area of 2.43 and 0.94 kg m−2 for vertical and horizontal systems, respectively. Productivity per unit area in the vertical systems was 160% greater than in horizontal systems. A significant effect of lighting, the height of the tray, and plant position inside the tray was found on plant growth parameters. Optimization of light source distribution and tray orientation can enhance the productive performance in vertical aquaponic systems. Electricity cost associated with supplemental lighting per kg of production increment was 21.84 and 12.25 $ kg−1 for the bottom and intermediate levels of the vertical system, respectively, the latter being economically the most profitable.

DesignLight Consortium released version 2.0 of Technical Requirements for Horticultural LED

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Submitted by Elsewhere on 2020-Sep-15 Tue 08:18

The DesignLights Consortium (DLC) today released the final version of its Technical Requirements for LED-based Horticultural Lighting: Version 2.0, an update that will continue the industry transition from traditional lighting data and metrics to horticultural-specific lighting data and metrics that best…

'We are developing a sustainable technology that uses 75% less LED lighting'

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Submitted by Elsewhere on 2020-Sep-08 Tue 10:13

Verde Compacto, a Mexican start-up, producer of container farms and indoor farming growing technologies, has seen significant demand for their growing systems during the pandemic.  'COVID is driving this market forward because people want to know what is behind their food and their diets. Logistic chains in…

Comparison of costs in greenhouse cucumber with LED or HPS

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Submitted by Elsewhere on 2020-Sep-08 Tue 10:12

The amount of energy used in agricultural production, processing and distribution is constantly increasing. During the winter months in the greenhouse production industry, the supplemental lighting required to keep up production levels results in high expenditure. Current technology uses broadband…