OK, apologies to whomever's thread I was on when I lost it_ I was going to reply about what I've been able to find out about light spectrum and intensity and how it can affect flavonoids, terpenes and cannabinoids....but then bam, it was gone.
I'm no expert but this is what I've been able to "distill" from a lot of confusing and misleading information, so I hope it helps for those interested.
Concerning spectrum in general one that provides for the best growth and development and provides a good amount of "white light" is the best choice. Regardless whether its LED or a lamp based source (or both). Cannabis does seem to use some green light so having some is better than having none.
In general all plants use a light spectrum between 400-700 nm.
Some lights don't provide any green light at all, so I prefer ones that produce a spectrum that includes all wavelengths.
I'm going to skip over the way PAR, PPF and PPFD affect plant growth under artificial lighting and move on to spectral enhancement.
The proportion of wavelengths as well as intensity can completely change the photomorphogenic outcomes as well as phytochemical concentrations of secondary metabolites- which affect the production of cannabinoids, terpenes and flavonoids in cannabis. This can affect plant quality in terms of cannabinoid & terpene production, flavonoids, color, resistance to disease, heat, light intensity, taste, scent, effects on humans, etc.
Increasing light intensity can also induce the production of various secondary metabolites.
Blue and UV light have the most powerful influence relative to other wavelengths and this scales with intensity. Some strains (or even individual plants) are more tolerant while others require more light intensity to display these variables. This is the hard part...knowing how much intensity of spectral enhancement you need to actually make a difference.
One method that can be used to get the best of both worlds is to use EOP (end of production) treatment when considering lighting. Initially plants are provided optimal conditions for growth and development (referred to as primary metaboiism) during their growth period through early flowering. White light perhaps enhanced with some blue light during the first few weeks has been found to work well. Once most of the growth process has been completed- basically until the last four weeks of flowering full spectrum combined with some supplemental warm light may be the best choice. An important thing to remember is the enhancement of secondary metabolic processes uses up some of the energy and nutrients that would otherwise be directed towards growth and development. But once most growth has occurred then enhancing with specific wavelengths and intensity can provide additional benefits.
For instance when considering flavonoids incremental increases in ppfd (umol/m2/s) of up to 100 umol/m2/s can significantly impact leaf color with the addition of blue light primarily.
Various terpenes that exhibit distinctive scents, flavors and effects can also be affected by spectrum and intensity. Increasing light intensity signals plants to produce more glandular trichomes (trichomes are where terpenes, flavonoids and cannabinoids are produced and stored by the plant). More trichomes make “frostier” and "tastier" buds! Cannabinoids are produced to protect against insect, heat and light damage.
UV light and possibly even short wavelength of blue light (400-420nm) can stimulate the production of cannabinoids, but the effect is thought to be more of a boost than a final result. Plants use several different photoreceptors and pigments that cooperatively regulate growth.
For instance rooting and leaf color can be affectively enhanced by light in the blue spectrum and flowering can often be affected by light in the yellow-red spectrum.
But if your light has a true full white light spectrum the addition of supplemental light may not really produce any benefits.
Most plants have developed under broad spectrum lighting_ basically white light, and get everything they need from within that spectrum.
But that doesn't mean some type of supplementation won't benefit your crop under the specific environmental conditions of your grow area.
This is why a lot of commercial growers use a combination of direct sunlight, LED and HID lighting_ to make sure their plants are getting everything they need to be their best.
Much is being investigated about which wavelengths of light provided at specific intensities at specific times during a plants life cycle can affect the production of different cannabinoids, terpenes and flavonoids. Once we obtain consistent research on these variables then we can design specific strains for very specific effects and results. Medical or recreational.
This research will be vital to the future of cannabis so support such research whenever possible and keep on sharing your experiences as well!
Cheers to all!
I'm no expert but this is what I've been able to "distill" from a lot of confusing and misleading information, so I hope it helps for those interested.
Concerning spectrum in general one that provides for the best growth and development and provides a good amount of "white light" is the best choice. Regardless whether its LED or a lamp based source (or both). Cannabis does seem to use some green light so having some is better than having none.
In general all plants use a light spectrum between 400-700 nm.
Some lights don't provide any green light at all, so I prefer ones that produce a spectrum that includes all wavelengths.
I'm going to skip over the way PAR, PPF and PPFD affect plant growth under artificial lighting and move on to spectral enhancement.
The proportion of wavelengths as well as intensity can completely change the photomorphogenic outcomes as well as phytochemical concentrations of secondary metabolites- which affect the production of cannabinoids, terpenes and flavonoids in cannabis. This can affect plant quality in terms of cannabinoid & terpene production, flavonoids, color, resistance to disease, heat, light intensity, taste, scent, effects on humans, etc.
Increasing light intensity can also induce the production of various secondary metabolites.
Blue and UV light have the most powerful influence relative to other wavelengths and this scales with intensity. Some strains (or even individual plants) are more tolerant while others require more light intensity to display these variables. This is the hard part...knowing how much intensity of spectral enhancement you need to actually make a difference.
One method that can be used to get the best of both worlds is to use EOP (end of production) treatment when considering lighting. Initially plants are provided optimal conditions for growth and development (referred to as primary metaboiism) during their growth period through early flowering. White light perhaps enhanced with some blue light during the first few weeks has been found to work well. Once most of the growth process has been completed- basically until the last four weeks of flowering full spectrum combined with some supplemental warm light may be the best choice. An important thing to remember is the enhancement of secondary metabolic processes uses up some of the energy and nutrients that would otherwise be directed towards growth and development. But once most growth has occurred then enhancing with specific wavelengths and intensity can provide additional benefits.
For instance when considering flavonoids incremental increases in ppfd (umol/m2/s) of up to 100 umol/m2/s can significantly impact leaf color with the addition of blue light primarily.
Various terpenes that exhibit distinctive scents, flavors and effects can also be affected by spectrum and intensity. Increasing light intensity signals plants to produce more glandular trichomes (trichomes are where terpenes, flavonoids and cannabinoids are produced and stored by the plant). More trichomes make “frostier” and "tastier" buds! Cannabinoids are produced to protect against insect, heat and light damage.
UV light and possibly even short wavelength of blue light (400-420nm) can stimulate the production of cannabinoids, but the effect is thought to be more of a boost than a final result. Plants use several different photoreceptors and pigments that cooperatively regulate growth.
For instance rooting and leaf color can be affectively enhanced by light in the blue spectrum and flowering can often be affected by light in the yellow-red spectrum.
But if your light has a true full white light spectrum the addition of supplemental light may not really produce any benefits.
Most plants have developed under broad spectrum lighting_ basically white light, and get everything they need from within that spectrum.
But that doesn't mean some type of supplementation won't benefit your crop under the specific environmental conditions of your grow area.
This is why a lot of commercial growers use a combination of direct sunlight, LED and HID lighting_ to make sure their plants are getting everything they need to be their best.
Much is being investigated about which wavelengths of light provided at specific intensities at specific times during a plants life cycle can affect the production of different cannabinoids, terpenes and flavonoids. Once we obtain consistent research on these variables then we can design specific strains for very specific effects and results. Medical or recreational.
This research will be vital to the future of cannabis so support such research whenever possible and keep on sharing your experiences as well!
Cheers to all!
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