Lighting in Design Q3 2022

An introduction to lighting for cannabis growth Contemporary indoor cannabis cultivation usually involves at least one of three artificial light sources: HID, CFL and LED; however, the LED industry for horticultural applications is growing rapidly due to the number of advantages it has.

C ultivators have been using natural light from the sun for years in greenhouses, although it isn’t always practical. This is where full spectrum LED grow lights come in as they mimic the sun’s natural light as closely as possible. Light spectrum is the range of wavelengths produced by a light. “As growers, we’re most interested in the wavelengths that are relevant to plants,” notes Nico Cahna from InDorSun. Plants detect wavelengths that include ultraviolet radiation (260–380 nm) and most of the visible spectrum which includes PAR (400–700 nm), and far-red radiation (700–850 nm). Full spectrum is what we are looking for. This includes all colours within the PAR zone. Light spectrum impact on cannabis plant Plants react to different spectrums, the ratio mix of different spectrums within a light is what makes the light different. • Violet (315-400nm): Improved THC and resin accumulation through defence mechanisms. • Blue (400-500nm) : Chloroplast and chlorophyl l development , leaf growth, compactness, regulates response to shade and stress.

• Green (500-565nm): Early stem growth, small amounts promote growth, large amounts can aggravate the stomata and cause lower THC. • Yellow (565-590nm): Mixed data, with the addition of yellow and green light, the result appears white to the human eye. Making it easier to identify and detect pests, pathogens and deficiencies. • Orange ( 590 - 625nm) : L i t t le data available, some increased yields. • Red ( 590 -700nm) : Improves l eaf nutrients, chlorophyll production and healthier seedlings. • Far red (700-780nm): Improves plant cell development, increase in overall growth, regulates flowering, mediates stresses. What is PAR? Photosynthetic Active Radiation (PAR) is the measure of total par that a light source produces; the total amount of light in the PAR zone that is produced by a light source is measured in micromoles per second or μmol·s-1. When purchasing LED grow lights, PAR is an important consideration because the more PAR your light can produce, the more PAR available to plants, the better they will grow.

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LiD Q3 - 2022