ZxcStaz
Active Member
Hi Pet,all 3000K-6500 cobs have 'green' in them, much more in the 6500s. You should not need to add any 'green'.
You want roughly 80% 6500 for veg, 50/50 for early flower then 20:80 (6500/3000) for flower
I did some more research on the colour spectrum vs. growth response and it supported my understandings pertaining to photosynthesis and plant biomass. In synopsis; UV has the most energy/power; the shortest wavelength. UV damages the cells, but also triggers the development of protective molecules e.g. terpenes/THC, it is not used in photosynthesis. Blue wavelengths provide the most photosynthetic energy, as they are more energetic. They will also have the greatest perpetrating power next to UV, but they are absorbed quickly and do not make it to the lower cells in a leaf. Greens penetrate the leaf, but they have limited, if any, photosynthetic ability, but they modify cellular responses. They irradiate below the canopy because they are reflected by the leaf, which may have a correlation to the observed stomal closing effect produced by green light. This could be the cause behind statements akin to ‘greens driving photosynthesis’ and these are a misinterpretations of the research. Red wavelengths exhibit a strong photosynthetic response, but only provide 2/3 the energy compared to blues. If a plant is provided only reds, it does not do well.
One study that I came across quantified the increase in plant development with varied amounts of red and blue light. It supports the hypothesis that a full spectrum; 30-50% Blue, Reds, UV (A/B) and a smattering of green, will be most conducive to growth. The creation of this spectrum should be possible with full spectrum COB LED's, Cool White COB LED's, and Warm White COB LED's.
Hogewoning, S. W., Trouwborst, G., Maljaars, H., Poorter, H., van Ieperen, W., & Harbinson, J. (2010). Blue light dose–responses of leaf photosynthesis, morphology, and chemical composition of Cucumis sativus grown under different combinations of red and blue light. Journal of Experimental Botany, 61(11), 3107–3117. http://doi.org/10.1093/jxb/erq132
Muneer, S., Kim, E. J., Park, J. S., & Lee, J. H. (2014). Influence of Green, Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.). International Journal of Molecular Sciences, 15(3), 4657–4670. http://doi.org/10.3390/ijms15034657