CDL agro grow light is two times more efficient than HPS grow light. Further enhancement of efficiency can be achieved by augmenting a portion of the CDL red light spectrum. The potency or taste of crops can also be improved by augmenting certain CDL spectrum. Tailor-made augmenting LEDs may even fertilize plants, control pests and mold, and boost shelf life of fruits and vegetables.
The augmenting light source is attached to the lower frame of CDL reflector hood for convenience and uniform illumination. The power source for augmenting light is located in the CDL ballast housing, mounted on the top frame.
Although other light sources such as fluorescent lamps may be used for augmenting CDL spectrum, LEDs are primarily used as augmenting light source to achieve superior color precision and high efficiency.
The following explains why red color augmentation increases plant photosynthesis:
The spectral curve of the CDL resembles sunlight providing 65% of its light energy around blue and red spectrum. The other 35% energy primarily in green and yellow regions. Most of the red light energy contains in between 600-680 nm.
Maximizing yield with less energy
Emerson effect (http://www.plantphysiol.org/content/39/1/10.full.pdf)
Professor Robert Emerson and coworkers in 1957 discovered that photosynthetic efficiency could be made to increase by simultaneous illumination of orange-red (660 nm) and far red (680 nm) light. Furthermore, Emerson observed that the yield obtained using both red and far-red light simultaneously was much higher than the sum of the yields obtained with red and far-red light separately.
Two different reaction centers or photochemical events are involved in photosynthesis, namely PS1 and PS2. PS1 is driven by far red light (680+ nm) PS2 is driven by red light (660 nm). Increased photosynthesis occurs when both events are driven simultaneously or in rapid succession.
There is sufficient scientific evidence that the concentration of tetrahydrocannabinol (THC) in both leaf and floral tissues increased with UV-B dose in drug-type cannabis plants. It is anticipated that narrowband source of UV-B is more effective than wide band UV-B.
BLI’s CDL+LED grow lights are engineered to incorporate UV-B LED arrays in the lower frame mounted panels. Linear UV fluorescent lamps can also be attached in these panels.
UV-B RADIATION EFFECTS ON PHOTOSYNTHESIS, GROWTH and CANNABINOID PRODUCTION OF TWO Cannabis sativa CHEMOTYPES by Lydon, Teramura, and Coffman, January 2008:
How to Use a UV Lamp to Increase THC by SIRIUS J, High Times, MAR, 2015
Cannabis researchers in Maryland exposed pot plants to ultraviolet radiation to see what would happen. They found that increasing doses of UVB radiation, a natural part of sunlight, made the plants produce almost 28% more THC in the buds.
The effects of light-emitting diode lighting on greenhouse plant growth and quality
by Margit Olle, Akvile Viršile, Agricultural and Food Science, 2013
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.