LED lighting is essential to some indoor growing operations, especially in areas with long winters and cold climates. LEDs offer many advantages over other lighting sources, such as fluorescent, including longevity, energy efficiency and lower temperatures. Furthermore, LEDs can be tuned to just the spectrum that growers need for particular plants. Read about a study that was done at Rensselaer Polytechnic Institute in New York State in which researchers studied how specific light spectra influences the concentration of nutrients in leafy greens.
A lighting company, Black Dog LED, recently developed a new lighting spectrum that they call Phyto-Genesis Spectrum. It combines multiple LEDs with discrete spectra to help indoor growers cultivate high-yielding plants. The spectrum includes ultraviolet (UV) and far-red/near-infrared (IR/NIR) for optimizing photosynthesis and the creation of secondary metabolites. They have found that the LEDs waste less light than high-intensity discharge as well as other LED lights, which causes the temperatures on leaf surfaces to remain lower, thus enabling a more energy efficient operation because less cooling is needed. The result is a better penetration of the plant canopy, which increases the yields.
The advantages of UV light
Black Dog LED uses UV light in its LEDs for several reasons. UV LEDs do cost more than LEDs in the PAR region of the spectrum. They also are less energy efficient because UV photons are more energetic than PAR photos, so it takes more electricity to create them. But the lighting specialists at Black Dog LED have found that UV lights grow the best plants with excellent canopy penetration.
The way it works is that UV light stimulates several different photomorphogenic responses in plants. The plants create higher levels of natural compounds that are trying to protect the plant from the ultraviolet rays. These can include terpenes, antioxidants, trichomes, flavonoids, THC, CBD and vitamins. This makes the PAR rating appear lower than other lights, but helps deliver more usable photons lower into the plant canopy.
Honey Creek Labs in Grove, Oklahoma (US), is a marijuana grower that installed the Black Dog LED PhytoMAX-2 1000 about six months ago in its flower grow rooms as well as a combination of other PhytoMAX-2 lights in its flower and propagation areas. David Vloedman, a grower at Honey Creek, said their goal is to have a high-quality, efficient grow facility.
Honey Creek Labs previously used halogen lights in both its flower and veg rooms. They installed 12 1,000-Watt Black Dog LED lights in two 400-square foot grow rooms, and there are 7 600's and some 200's. The larger lights are not necessary for veg room, as the plants have 18 hours to get their daily light requirement, as opposed to just 12 hours in the flower room.
Andrew Stewart, Honey Creek Labs CEO said that before they made the purchase, they chose the LEDs carefully. “We did tons of research because we believed that the full Spectrum could be achieved with the LEDs and we knew the power savings would be there.” While Stewart and his team knew the benefits of UV LED lighting when they made the purchase, they didn’t know how much of a difference it would make with the product. “It’s for real,” Stewart said.
The UV LEDs are about 7 to 8 times as expensive as regular LEDS, according to Stewart, but they use much less electricity and have other advantages as well, “We can keep our rooms at a hotter temp because the lights don’t put off as much heat,” Steward noted, adding that, “It costs less to run them and less to cool the rooms.”
As far as challenges and difficulty of use, Stewart said, “With everything there is a learning curve, but it wasn’t much because the guys at Black Dog LED shared their experience to help us big time.” In just six months’ time, they’ve already seen impressive results. In the first harvest since the lights were installed, they averaged 2 pounds per light, an improvement over the industry average of 1.37 pounds in the same grow space (commonly under high-pressure sodium lighting). Stewart noted that this is only a start because yields are continuing to rise. It’s too early to calculate a return on investment, but Stewart is confident that it’s going to be well worth it. “It won’t take long to make the up-front investment pay back.
Written by Anne Fischer, Managing Editor, Novus Light Technologies Today