Full Cannabis Genetic Expression Starts with High Radiant Intensity Light

Cannabis craves bucketloads (30-40 mol) of full spectrum, high radiant intensity sunlight each day. It has also adapted to tolerate high levels of ultraviolet (UV) due to the elevation of many of its natural habitats. This ultraviolet radiation would quickly see off other types of plant—particularly those more accustomed to shade or partial shade at sea level. It’s taken millions of years of natural selection for cannabis to achieve these important adaptations. The production of tetrahydrocannabinol (THC) for instance, is partly regulated by the UVR8 gene which is activated by the presence of incident UV. THC absorbs UV—so it’s kind of like a protective layer of sunscreen for the plant. Therefore, in order for cannabis plants to fully express their genetic encoding, they need to be stimulated with high intensity, full-spectrum light.

As cannabis seed breeders, achieving full expression of our plant genetics is of paramount importance. We need to make the best selections possible in order to create the highest quality seed stock. Working with anything less than the very best horticultural lighting available just isn’t an option. Quality, high radiant intensity light drives everything we do!

Of course, there are no shortage of lighting options available today—and we are often asked by our customers which grow lights we would recommend. We chose the latest generation of ceramic metal halide lighting systems—the Hellion 315W CMH illumination kit by Adjust-A-Wings—because of their spectral quality, reflector design (engineered for close proximity) and unparalleled ability to drive both incredible growth and vigour. The lamps emit more UV and more deep red than the first generation of Philips CDM lamps. This means that we enjoy squatter, bushier plants with more bud sites—and much, MUCH more resin production. The spectral distribution is a lot smoother too—mimicking natural incident solar radiation a lot more closely.

In conclusion, by giving our cannabis plants UV from the get go, the UVR8 gene is fully stimulated at the earliest possible opportunity. This cues the plant to start assembling the pre-metabolites of THC, so that when the light cycle is changed to 12/12 to initiate flowering, it already has its “ducks in a row”. By growing and blooming our plants under Hellion new generation CMH, we observe more interesting colours and stand-out terpene profiles. Even some of our own familiar genetics surprised us when we first grew them under this light source.

We use both 3K and 4K lamps—the 4K being richer in blue than the 3K. What’s more, the titanium dioxide coated Adjust-A-Wings Defender reflectors do a much better job of reflecting UV than regular PVD aluminium. So the UV actually gets to our plants, rather than just heating up the reflector.

Thanks to the unique, double-parabolic design of Adjust-A-Wings reflectors, we are able to position the lamps much closer to the canopy—driving top tier flower production deep into the plant. Radiant emissions (including infrared heat) are evenly and accurately distributed across the footprint without causing heat issues. The plant response—as you can see from the photos—is truly incredible. Basically—it’s a lot closer to the Sun! All the light from each fixture emanates from a single arc tube—this gives the light more penetrative power than an equivalent multiarray LED—because larger groups of photons travel along the same paths. (Our colleagues over at Adjust-A-Wings liken this difference to a fireman’s hose versus a garden mister spray.)

So growers! Remember what you’re dealing with—cannabis is a veritable light hog! It has evolved for millions of years to deal with huge amounts of solar radiation. The Hellion 315W CMH is the most efficient lighting fixture we have found that can truly match the qualities of the Sun. Based on our experiences, we urge you to check this fixture out before investing in more expensive and less efficacious lighting fixtures.