Far Red Light and Cannabis Plant Growth

Dr. Mark Lefsrud, Ph.D., McGill University talks about the light spectrum, far-red light and emerging research from Dr Bruce Bugbee related to far-red light and …


  1. "We try to explain something that the science does not have the full understanding of yet," hence the entourage effect is just as it is within cannabinoid profiles, it applies to the light's photosynthetic photon flux studies… much more to discover.

    Red and Far-Red will cause the cell-elongation and expansion, hence the weaker, but longer leaves on the plant grown under all red (however, you should try growing under a red light which spans all way past the 700nm wavelength and includes at least 10% of the red spectrum in far-red).

    Lettice only needs about 500 micro mol/m^2s, corn or hemp on the other hand needs about 2000 micro mol/m^2s, so the distance and the measurement of the photosynthetic flux efficiency is a must.

    Also, the myth that the green light is reflected and useless for the plant growth and photosynthesis should be addressed. You should check out the light penetration curve based on the leaf thickness. Red and Blue penetrate very little into the leaf, green and far-red however, penetrate ALL the way through the leaf, hence stimulating a lot more mitochondrial and cellular / chlorophyll activity.

    P.S. Blue light normally inhibits cell elongation, making the plants more bushy vs. red light (similar effect to the gibberellic acid which will cause the internodal stem elongation… just something to think about = gibberellic acid + all red + far-red = would make for a cool experiment).

    Far-red photons stimulate the Photosystem 1 (the NADPH pathway) and have a tremendous effect on the yields (only 15% of the total spectrum in far-red results in 35% of the plant mass boost increase at harvest). Far-red alone isn't sufficient, just as an isolate of a single cannabinoid will never deliver the same effect as a full-spectrum extract (however, the cannabinoid and terpene rations is where the research should be focused on (in hemp cannabinoid profile blends and in the light's spectral distribution curves.)

  2. Are we ever going to get to the point of saying "We need THAT wavelength of THAT frequency of far-red at THIS many weeks in, and THAT wavelength of THAT UVB frequency at THIS many weeks in…on THIS strain, in order to completely eliminate epileptic seizures in MALE patients between the ages of 13-42"…?

  3. Wow interesting, Dr. Lefsrud is extremely knowledgeable and keen. He knew all the answers to the questions no matter how irrelevant. Definitely shined some light on spectrum optimization.
    Keep to a broad spectrum without UV/FR when vegging so they don't penetrate into the roots.
    Then during flower, introduce UV/FR to stress out the plants into producing potent buds.
    Be sure to use UV/FR with your broad spectrum NOT by itself to maximize an "entourage effect"

  4. pulse sequences through different discrete wavelengths, at photosynthesis refresh rate. . . . i forget the names of those who did superb work on pulse timings. lets you over charge the leds briefly. much more efficient, not wasting energy putting light out while the plant's in a photosynthesis out-breath (so to speak). i was just wondering if pulsing different colours at the photosynthetically active frequencies, in the same way, without mixing (or with, variously), and if colour sequence order can be discerned for optimisations… … if that makes sense. sry, sleepy typing.

  5. Hey you should check out my new review I just did to celebrate 100 subs death bubba and mk ultra kief or my moon rock Review I got a bunch of strains and shatters and hash to u may like n I do rap news to if u are a fan

  6. Amber is important for bud bulking, but it doesn't seem to increase resin. Yes, 730nm and the Emerson effect requires blue and red, but also green, because those two are the only colors that penetrat the leaves completely.

  7. mcgill is a enemy funded by the sackler aka perdue , if they want a crop for standart exactitude just create a pill or a inalor ,cannabis is not what your looking for ,it like me and all user different and special.you are the real image of the corrupt effect on canadian socal légalisation ,they always are against user they produce paper on the danger of cannabis with fear mongering and lies including example of synthesized cannabis like k2 ,like a cannabis product.they also and put in place a register for access to medical cannabis were the law was not respected like the option for patient to refuse to be included in a registry and not produce is hown cannabis ,option to grow was rejected even with a prescription the chief directeur mark ware quit and now working with the biggest private cannabis companies,the same guys that help but in place the bill on legalize cannabis v.p of the task force.those are fax so Future Cannabis Project do not give time to help the big pharma invaded
    more jodrey more frenchie, peace

  8. So they don't really have any evidence yet.
    200 watts of 2700k or 160 watts 2700k with 40 watts far red which is best, I'm pretty sure 1 costs more and has hardly any effects on yields.

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