gojo
06-18-2007, 07:38 AM
Hi,
I've been reading up on some excellent and very advanced info posted by a guy called "knna" on another forum (hempcultivation.com). Knna cobbled together his "Cannabis Sativa Chlorophyll Abosrbance Spectra" (CSCAS) using a combination of existing non-cannabis "Chlorophyll Absorbance Spectra" (CAS) and satellite images of cannabis sativa in Columbia (this guy is smart):
Knna:
I used a article about detecting MJ fields from sky (planes/sat) of Us gv to build a curve of MJ absorbance of each wavelenght...[snip]...spectral plots of colombian sativa transmitance/absorbance/reflectance.
So it looks like Knna took the existing CAS and combined that with his interpretation of Us Gov photos to get his CSCAS. Then he multiplied his CSCAS with the "Action Spectra for Photosynthesis" (ASP) to come up with the "Quantum Yield Curve (QYC) for Cannabis".
Note #1: This is the normal method to find the QYC of higher plants (ASP x CAP).
Note #2: I do not fully agree with Knna's CSCAS as it does not match the most current scientific data on higher plants CAS and CCAS (Chlorophyll Carotenoids Absorption Spectra). His CSCAS shows more absorption in the orange-red spectra; while the CCAS shows most absorption taking place from 400-500 with Chlorophyll A & B along with Carotenoids. The blue spectra plays an equally if not more important role in absorption and it also offers a higher rate of photosynthesis.
Here's his excellent post:
http://www.hempcultivation.com/420/theories-speculation/88393-cannabis-quantum-yield-bulbs-comparing.html
QYC for Cannabis
Knna:
The graph's blue line is absorbance curve. Red curve is the Inada one. Yellow curve is Quantum Yield curve (absorbance X action spectrum). Light blue curve is QY corrected for the relative energy of photons (700nm is choosen arbitrary like 1), we need it if the bulb spectral distribution is given in mW (usually). Using QY corrected dont provide any scale, its pure adimensional (so using 400nm as 1 result in a very dif curve), but give valuable info when comparing spectral distribution of dif bulbs.
http://img2.freeimagehosting.net/uploads/46224011fe.jpg (http://www.freeimagehosting.net/)
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And here's why all the above is not an overly important factor in quality cannabis growth:
1-The most important factor in regards to plant usable light energy is PPF and to a greater degree PPFD.
2-The plant response I call "Spectral Adaptation" (SA) is when plants adapt their photosynthetic apparatus to match the lightwave environment. For example plants will adjust their ASP to match the major section of PAR (blue/green/red) they are being grown in:
See this url for the full study: http://ncr101.montana.edu/Light1994Conf/1_3_Tikhomirov/Tikhomirov%20text.htm
This pic shows the photosynthesis' action curve of radish. The solid line correspond to the mean of Inada and Mc Cree curves (standard ASPs), while curve 1 correspond to radish grown under green dominant light and curve 2 correspond to radish grown under blue dominant light. Notice the large differences between. The ASP is calculated for unit energy irradiations, so changes correspond to both canopy's photons absorbance and quantum yield.
http://img2.freeimagehosting.net/uploads/a95ceffb3b.jpg (http://www.freeimagehosting.net/)
Results:
From the study:
Therefore, usage of the curve for action spectrum of photosynthesis is not correct in light regulation under long-term stationary regimes...[snip]
I wondering how long "long-term" is in regards to radishes. So I looked it up and it takes radishes average of 40 days to mature. Cannabis takes an average of 70 days to mature so that is plenty of time for SA to take effect...with the end result of marginalizing the importance of ASP, CAP, QYC, etc...to a certain degree. To what degree I do not know
-----------------------------------------------------------------------
Results:
As long as a bulb is emitting 1200-2000 PPF* it is a good bulb...with the caveat you keep the bulb close to the canopy as possbile (thus negating the need to figure the PPF/D which is not a trivial task). PPF is a much more important factor than specific spectral measurements in regards to PPF per nm (eg. PUR**) or otherwise.
*PPF levels as a point of reference:
-At noon in mid-winter: 1200 PPF
-At noon in mid-summer: 2000 PPF
-Tomato and other sun-loving veg/fruits: 400-1000 PPF
**If PUR is also used as a form of measurement use 600-800 PUR per meter squared for a close approximation of 60-80 wpsf:
-600-800 PUR pms = 65-85 PUR psf
-65-85 PUR psf = 60-80 wpsf
---------------------------------
Due to Spectral Adaptation and other un-quantified variables (accessory pigments, blue light photo-receptors, cytokinins, etc) I think a 60:40 or even 50:50 [1:1] ratio of blue (400-500nm) to red (600-700nm) of PARA and/or PPF (eg. PUR) is most beneficial...regardless of MH or HPS HID
---------------------------------
:D
I've been reading up on some excellent and very advanced info posted by a guy called "knna" on another forum (hempcultivation.com). Knna cobbled together his "Cannabis Sativa Chlorophyll Abosrbance Spectra" (CSCAS) using a combination of existing non-cannabis "Chlorophyll Absorbance Spectra" (CAS) and satellite images of cannabis sativa in Columbia (this guy is smart):
Knna:
I used a article about detecting MJ fields from sky (planes/sat) of Us gv to build a curve of MJ absorbance of each wavelenght...[snip]...spectral plots of colombian sativa transmitance/absorbance/reflectance.
So it looks like Knna took the existing CAS and combined that with his interpretation of Us Gov photos to get his CSCAS. Then he multiplied his CSCAS with the "Action Spectra for Photosynthesis" (ASP) to come up with the "Quantum Yield Curve (QYC) for Cannabis".
Note #1: This is the normal method to find the QYC of higher plants (ASP x CAP).
Note #2: I do not fully agree with Knna's CSCAS as it does not match the most current scientific data on higher plants CAS and CCAS (Chlorophyll Carotenoids Absorption Spectra). His CSCAS shows more absorption in the orange-red spectra; while the CCAS shows most absorption taking place from 400-500 with Chlorophyll A & B along with Carotenoids. The blue spectra plays an equally if not more important role in absorption and it also offers a higher rate of photosynthesis.
Here's his excellent post:
http://www.hempcultivation.com/420/theories-speculation/88393-cannabis-quantum-yield-bulbs-comparing.html
QYC for Cannabis
Knna:
The graph's blue line is absorbance curve. Red curve is the Inada one. Yellow curve is Quantum Yield curve (absorbance X action spectrum). Light blue curve is QY corrected for the relative energy of photons (700nm is choosen arbitrary like 1), we need it if the bulb spectral distribution is given in mW (usually). Using QY corrected dont provide any scale, its pure adimensional (so using 400nm as 1 result in a very dif curve), but give valuable info when comparing spectral distribution of dif bulbs.
http://img2.freeimagehosting.net/uploads/46224011fe.jpg (http://www.freeimagehosting.net/)
-----------------------------------------------------------------
And here's why all the above is not an overly important factor in quality cannabis growth:
1-The most important factor in regards to plant usable light energy is PPF and to a greater degree PPFD.
2-The plant response I call "Spectral Adaptation" (SA) is when plants adapt their photosynthetic apparatus to match the lightwave environment. For example plants will adjust their ASP to match the major section of PAR (blue/green/red) they are being grown in:
See this url for the full study: http://ncr101.montana.edu/Light1994Conf/1_3_Tikhomirov/Tikhomirov%20text.htm
This pic shows the photosynthesis' action curve of radish. The solid line correspond to the mean of Inada and Mc Cree curves (standard ASPs), while curve 1 correspond to radish grown under green dominant light and curve 2 correspond to radish grown under blue dominant light. Notice the large differences between. The ASP is calculated for unit energy irradiations, so changes correspond to both canopy's photons absorbance and quantum yield.
http://img2.freeimagehosting.net/uploads/a95ceffb3b.jpg (http://www.freeimagehosting.net/)
Results:
From the study:
Therefore, usage of the curve for action spectrum of photosynthesis is not correct in light regulation under long-term stationary regimes...[snip]
I wondering how long "long-term" is in regards to radishes. So I looked it up and it takes radishes average of 40 days to mature. Cannabis takes an average of 70 days to mature so that is plenty of time for SA to take effect...with the end result of marginalizing the importance of ASP, CAP, QYC, etc...to a certain degree. To what degree I do not know
-----------------------------------------------------------------------
Results:
As long as a bulb is emitting 1200-2000 PPF* it is a good bulb...with the caveat you keep the bulb close to the canopy as possbile (thus negating the need to figure the PPF/D which is not a trivial task). PPF is a much more important factor than specific spectral measurements in regards to PPF per nm (eg. PUR**) or otherwise.
*PPF levels as a point of reference:
-At noon in mid-winter: 1200 PPF
-At noon in mid-summer: 2000 PPF
-Tomato and other sun-loving veg/fruits: 400-1000 PPF
**If PUR is also used as a form of measurement use 600-800 PUR per meter squared for a close approximation of 60-80 wpsf:
-600-800 PUR pms = 65-85 PUR psf
-65-85 PUR psf = 60-80 wpsf
---------------------------------
Due to Spectral Adaptation and other un-quantified variables (accessory pigments, blue light photo-receptors, cytokinins, etc) I think a 60:40 or even 50:50 [1:1] ratio of blue (400-500nm) to red (600-700nm) of PARA and/or PPF (eg. PUR) is most beneficial...regardless of MH or HPS HID
---------------------------------
:D