1. Help Us Improve the Grasscity Growing Journal!

    We're rebuilding the Growing Journal feature and want your input. What tools or features should we add? What other platforms do you use and love?

    Click here to share your feedback!
    Dismiss Notice

New Study on Lighting, Potency and Yield

Discussion in 'Lighting' started by Storm Crow, Nov 14, 2022.

  1. #1 Storm Crow, Nov 14, 2022
    Link leads to the full study.

    Light Quality Impacts Vertical Growth Rate, Phytochemical Yield and Cannabinoid Production Efficiency in Cannabis sativa
    Light Quality Impacts Vertical Growth Rate, Phytochemical Yield and Cannabinoid Production Efficiency in Cannabis sativa

    Abstract
    Light is one of the most crucial parameters for enclosed cannabis (Cannabis sativa) production, as it highly influences growth, secondary metabolite production, and operational costs. The objective of this study was to investigate and evaluate the impact of six light spectra on C. sativa ('Babbas Erkle Cookies' accession) growth traits and secondary metabolite (cannabinoid and terpene) profiles. The light spectra evaluated included blue (430 nm), red (630 nm), rose (430 + 630 nm, ratio 1:10), purple (430 + 630 nm, ratio 2:1), and amber (595 nm) LED treatments, in addition to a high-pressure sodium (HPS, amber-rich light) treatment as a control. All the LED light treatments had lower fresh mean inflorescence mass than the control (HPS, 133.59 g plant-1), and monochromatic blue light yielded the least fresh inflorescence mass (76.39 g plant-1). Measurement of Δ9-tetrahydrocannabinol (THC) concentration (%) and total yield (g plant-1) showed how inflorescence mass and THC concentration need to be analyzed conjointly. Blue treatment resulted in the highest THC concentration (10.17% m/m), yet the lowest THC concentration per plant (1.44 g plant-1). The highest THC concentration per plant was achieved with HPS (2.54 g plant-1). As with THC, blue light increased cannabigerol (CBG) and terpene concentration. Conversely, blue light had a lesser impact on cannabidiol (CBD) biosynthesis in this C. sativa chemotype. As the combined effects of the light spectrum on both growth traits and secondary metabolites have important ramifications for the industry, the inappropriate spectral design could cause a reduction in cannabinoid production (20-40%). These findings show promise in helping producers choose spectral designs that meet specific C. sativa production goals.
     
    • Like Like x 2
    • Winner Winner x 1
  2. #2 trojangrower, Nov 15, 2022
    • Like Like x 2
  3. #3 Storm Crow, Nov 15, 2022
    @trojangrower If you look at the list of authors, Mark Lefsrud has an email link icon next to his name. Why don't you ask him? I've been known to occasionally send emails to the authors of studies.

    A few years back, I even got invited to join in on one author's next study! But it was in Iran, and I don't think an old hippie like me would be appreciated in Iran! :hide: (FYI- It was on improving the fertility of cattle by adding hemp seed to their diet. Hemp seed almost doubled their fertility! Cattle in Iran apparently are badly malnourished. :coolalt: )

    Nor do I want to be on some FBI list, again! :eek2:

    So I politely declined (although it would be fun to see "Granny Storm Crow" listed as an author on a study! lol) .

    Granny :wave:
     
    • Agree Agree x 1
  4. #4 dan min, Nov 15, 2022
    Aircon and hid is still my favourite. My se3000 still feels strange but it keeps a green garden without aircon.
     
    • Like Like x 1
  5. #5 trojangrower, Nov 15, 2022
    Stormcrow, you are the #1 cannabis reviewer, published or not. Your yearly lists and other posts are very important contributions that I've used in my own work.
    As far as academia, I'm not overtly thrilled with the lot. Oh if you only knew ...
    I was just pointing out that the light ratio, although a neat idea, isn't really beneficial if you aren't working at Samsung, where the diodes have advanced to the LM301h series.

    Maybe I will send the authors an email though. Just for fun ;)
     
  6. #6 rightsideup, Dec 4, 2022
    Two problems I see with this, without reading it thoroughly, they compared what is essentially a full spectrum light but with a concentration at about 600 nm with lights that had much less spectrum, with the Amber being the greatest spectrum.
    They also only tell you relative intensity, not absolute.
    Like I said I just did a quick browse of it, so maybe that's in there.
     
  7. #7 FullSpec, Dec 19, 2022
    These studies are so irrelevant and misleading. No I did not even read it. I’m willing to bet it is not worthy information that will not help you or any manufacturers though. Is there anyone here that read it and believe I am wrong? Let’s get a show of hands that actually believe they stand to gain by using Mi-Gros list of good lights as a reference to purchasing their own? Has anyone any idea why White light or Burple (whichever you prefer) is said to be good for horticulture? Has anyone any idea who originally promoted Burple and or White leds? What’s your led spd look like & what would one look like that is optimized. Thx! Just trying to understand why growers believe common misconceptions.
     

Share This Page