Light spectrum might be one of the most underrated factors when it comes to cannabis production. Not only only does light affect the plant health but also the environment in which the plant is growing in. Having better control of your environment allows for more consistent production and overall health of the plant. When it comes to specific spectrums for cannabis there is a lot of information that points to the benefits of having a full spectrum.
Heliospectra has also done extensive studies on this and that is why our LED is not only full-spectrum but blended light as well. Having green light within your spectrum allows for denser canopies due to the green's abilty to penetrate through the leaves.
We are also finding that cannabis is very responsive to the wavelength of light in the far red region as well. This is a very specific wavelength that trigges the flowering response in flowering plants. This will accelerate flowering and decrease your flowering times 5-14 days(strain dependent).
You can also start to control secondary metabolite production with spectrum manipulation. Many growers will expose their plants just to blue light just days before harvest to increase THC and terpenes.
Lastly having the correct spectrum of light keeps an overall healthier plant. Their natural resistance to pest and molds becomes greater. With IPM becoming more and more important everyday this will assist in these efforts rather than working against you.