B
BobbyDigital
Guest
The Evolutionary Effects of Ultraviolet-B Radiation on the Psychoactive Potency and Cannabinoid Content of Cannabis sativa L.
Written by BobbyDigital for Overgrow.com
March 25, 2004
After a review of some scientific literature relating to the psychoactive potency of Cannabis, it is the author's opinion that Ultraviolet-B type radiation is the single most important environmental factor for developing varieties with highly narcotic properties. Ultraviolet-B radiation (UV-B) is defined as that part of the electromagnetic spectrum between 280 and 315 nanometers.
Cannabis sativa has two main chemotypes, one almost devoid of psychoactive principals ("fiber-type") and the other with an abundance of said principals. This is actually where the taxonomical split between C. indica and C. sativa originated, when in 1793 Lamarck named Cannabis indica as a distinct species from Cannabis sativa because of slight morphological differences, but mainly because of the intense mind-altering effects after ingestion of C. indica, as opposed to the fiber-type C. sativa (Schultes and Hofmann, 1980(?)). Almost every "fiber-type" variety has been grown outside the range of intense levels of UV-B radiation, whereas the opposite is true for "drug-type" varieties. This can be seen in a chart made by David Pate for his Ph.D. dissertation for the University of Missouri, where he used the data of Small and Beckstead (1973), taking careful steps to disqualify any varieties whose origins could have been in question, and plotted their THC content in relation to their UV-B radiation intensity (Image 1), and also their THC to CBD ratio in relation to UV-B radiation intensity (Image 2). About the data he says,
In John Lydon's Ph.D. dissertation, he showed experimentally that Cannabis plants irradiated with intense UV-B had a higher content of delta-9-THC and a lower content of CBD than those without UV-B. Although his experiment did not use clones, he reported a significant 38% difference in the content of delta-9-THC. (Lydon, 1985). Another issue he reported about was that Cannabis was morphologically and physiologically insensitive to UV-B radiation. That means that the plant did not encounter any growth changes or health problems in an area of UV-B exposure equal to that of 3000 Meters above sea level at 0 degrees latitude. Also in his dissertation are two graphs that show the strikingly different cannabinoid contents between "fiber" and "drug" Cannabis with the "fiber-type" coming from high latitude origins and the "drug-type" coming from low latitudes originally (Images 4 and 5). He quotes a different article from David Pate (Pate, 1983) when he says that Pate,
Although further investigation is needed along this line of inquiry, the theory is somewhat supported by Robert Nelson when he writes,
Lydon wrote a good summary of the issue about UV-B radiation and Cannabis potency when he stated,
The first, aallonharja, though only using a 15 Watt tanning fluorescent bulb, but failing to report his strain or growing conditions stated a
Out of the five people to have added supplemental UV-B to their indoor growing environments and reported about it, four report an increase in the narcotic properties of their final product. Three felt that there was such a difference that they will not go back to using no UV-B supplementation. Sam_Skunkman reported no difference, although the strain he used and procedure were never reported. aallonharja, despite reporting a positive increase in resin production, felt it wasn't important enough to do again, but that could be due to the fact that he is an extremely experienced cultivator and there was not that much psychoactive difference between his products with UV-B and those without. Now that a direct correlation has been shown between UV-B radiation and the potency of Cannabis, one would suspect more people attempting UV-B supplementation in their indoor environment, with positive results reported.
In support of the fact that Ultraviolet-B radiation positively influences the narcotic properties of Cannabis, one could look at the writings of Ed Rosenthal, an author who specializes in indoor Cannabis growing. He seems to believe that UV-B is important in growing a narcotically potent Cannabis plant. His advice has been taken by more people on indoor Cannabis growing than any other author, mostly from his "Ask Ed" column which appears in Cannabis Culture magazine, or his best selling books on Cannabis growing. There have been at least two "Ask Ed" articles that speak of UV-B radiation, both in a positive light.
The first is from the November 2002 issue of Cannabis Culture in an article entitled "Light Disagreement", where an individual claims that Metal Halide HID lamps are better for the flowering cycle because of the UV radiation emitted by them. The person claims,
The scientific data has shown that intense levels of Ultraviolet-B radiation have been the single most important environmental factor in developing Cannabis varieties with highly narcotic properties. The environmental stress of UV-B radiation coupled with the obvious artificial or cultural selection carried out by the human race, has resulted in varieties of Cannabis with large quantities of the psychoactive principal delta-9-THC. It would seem that today, Cannabis breeders are focused mainly on artificial selection, with little or no emphasis on the environmental factors that would affect the cannabinoid biosynthetic pathway, content, and ratio.
The author has no knowledge of modern breeders trying to give their plants an intense level of UV-B radiation, although it would seem that this was the case for cultivators in the distant past. With the amount of high quality, highly narcotic Cannabis strains available today, it would seem that the last step would be to give the plant a supplemental dose of Ultraviolet-B type radiation equal to that of low-latitude or high-altitude environments in order to fully develop the biosynthetic pathway to THC with little or no CBD involved. The lack of UV-B radiation in a Cannabis growing environment would effect the potency of the mind-altering attributes, as in the plant would not be as narcotic as if there was a quantifiable level of UV-B radiation in the light. Highly potent Cannabis can be grown without UV-B radiation being represented due to intense cultural selection, although it would seem that almost all the strains grown today are originally from areas of intense UV-B radiation.
Ultraviolet-B radiation is the single most effective environmental stress to increase the psychoactive potency of Cannabis. In fact, it's evolutionary, and over the years, along with a human hand, it has played the most important role in developing Cannabis with large quantities of its main psychoactive principal, delta-9-THC. The words of David Pate can best conclude this discourse when he wrote,
Written by BobbyDigital for Overgrow.com
March 25, 2004
After a review of some scientific literature relating to the psychoactive potency of Cannabis, it is the author's opinion that Ultraviolet-B type radiation is the single most important environmental factor for developing varieties with highly narcotic properties. Ultraviolet-B radiation (UV-B) is defined as that part of the electromagnetic spectrum between 280 and 315 nanometers.
Cannabis sativa has two main chemotypes, one almost devoid of psychoactive principals ("fiber-type") and the other with an abundance of said principals. This is actually where the taxonomical split between C. indica and C. sativa originated, when in 1793 Lamarck named Cannabis indica as a distinct species from Cannabis sativa because of slight morphological differences, but mainly because of the intense mind-altering effects after ingestion of C. indica, as opposed to the fiber-type C. sativa (Schultes and Hofmann, 1980(?)). Almost every "fiber-type" variety has been grown outside the range of intense levels of UV-B radiation, whereas the opposite is true for "drug-type" varieties. This can be seen in a chart made by David Pate for his Ph.D. dissertation for the University of Missouri, where he used the data of Small and Beckstead (1973), taking careful steps to disqualify any varieties whose origins could have been in question, and plotted their THC content in relation to their UV-B radiation intensity (Image 1), and also their THC to CBD ratio in relation to UV-B radiation intensity (Image 2). About the data he says,
And,
This is a rather interesting observation, and one that has been noted by Bouquet,
And,
Bergel reported similar findings when he wrote,
David Pate discusses Bouquet when he says,
He goes on to say,
Other data he found supporting his idea was from Davis et al., who in 1963 analyzed and plotted Cannabis from Morocco, Greece, Brazil, Canada, Switzerland, Germany, and a seizure sample thought to be from Mexico (Davis et al., 1963). In it, Davis found while comparing high latitudes and tropical climates that,
Not long after that, at the first symposium organized by the Institute for Drug Dependence, whose topic was Cannabis, the topic of UV-B radiation was slightly covered. In the discussion on biosynthesis, when Agurell was discussing the cannabinoid content from an experiment, this discussion took place,
The chart that David Pate made showing the ratio of THC/CBD in relation to origin can also be seen slightly changed (names of origins added) in Robert C. Clarke's book Marijuana Botany on page 159 (Image 3). From this, Clarke concludes,
He does hint at the reason why when he says,
Although Clarke would like to contribute this to longer days, he failed to realize that intense UV-B radiation is another important factor missing from climates outside 35 degrees North and South latitude.
In John Lydon's Ph.D. dissertation, he showed experimentally that Cannabis plants irradiated with intense UV-B had a higher content of delta-9-THC and a lower content of CBD than those without UV-B. Although his experiment did not use clones, he reported a significant 38% difference in the content of delta-9-THC. (Lydon, 1985). Another issue he reported about was that Cannabis was morphologically and physiologically insensitive to UV-B radiation. That means that the plant did not encounter any growth changes or health problems in an area of UV-B exposure equal to that of 3000 Meters above sea level at 0 degrees latitude. Also in his dissertation are two graphs that show the strikingly different cannabinoid contents between "fiber" and "drug" Cannabis with the "fiber-type" coming from high latitude origins and the "drug-type" coming from low latitudes originally (Images 4 and 5). He quotes a different article from David Pate (Pate, 1983) when he says that Pate,
In Pate's closing paragraph he says,
Pate does not get into finding out why this phenomenon occurs in his dissertation, but he does discuss it some time later in 1994 when he published the "Chemical Ecology of Cannabis." The papers subject was the environmental factors that affect the potency of Cannabis, and UV-B radiation is covered in detail. He says,
He explains later, saying,
He then gives two explanations for the phenomenon. First, THC would be more energetically efficient to produce because it would last longer as a UV-B blocker than CBD. The other explanation is,
He goes on to say,
It is Pate's understanding that the biosynthesis of THC can happen along different routes using different precursor cannabinoids, depending on environmental factors. CBD and THC have the same UV-B absorptive properties, except CBD readily breaks down upon exposure to UV-B, while THC does not. The cannabinoid CBC has significantly higher UV-B absorptive properties than both CBD and THC. CBD would then be viewed as energetically inefficient in areas where additional UV-B screening is needed. The plant would then take an alternate biosynthetic route, creating CBC from CBG to get to THC. This route would provide the plant with the UV-B protection it needed, whereas the route involving CBD would be less functional for that purpose.
Although further investigation is needed along this line of inquiry, the theory is somewhat supported by Robert Nelson when he writes,
And also by Bassman when speaking in general of UV-B radiation's effects on plants,
In our case, CBC would be increased because of its UV-B absorptive properties, and CBD would decrease because it readily degrades upon UV-B exposure. Bassman then goes on to say,
In our case, this would be relevant in the biosynthesis from CBG to THC through either CBD or CBC, with the CBC route given evolutionary favor in areas of intense UV-B.
Lydon wrote a good summary of the issue about UV-B radiation and Cannabis potency when he stated,
There has been a large group of individuals in modern times, who for various reasons attempt to grow Cannabis indoors under artificial lighting for its narcotic properties. These individuals try to mimic the output of the sun as closely as possible in order to grow their plant to their highest potential, although intense UV-b radiation is never represented in their indoor environments, mainly due to lack of information on UV-B's effects on Cannabis potency. There have been a few select individuals who have gone through the pains to supplement their HID (High-Intensity Discharge, the most common type of lamp used for this purpose) lighting with UV-B producing lamps and reported their findings, with almost all of them reporting positive results. This was observed on the Internet Cannabis growing community Overgrow.com. On that website, there have been five people who've supplemented UV-B through the whole life cycle of a Cannabis plant, aallonharja, Alchemy Grower, middle_aged_crazy, maxgrow_de, and Sam_Skunkman.
The first, aallonharja, though only using a 15 Watt tanning fluorescent bulb, but failing to report his strain or growing conditions stated a
although he felt it wasn't worth the trouble. middle_aged_crazy has added supplemental UV-B lamps to his indoor environment, with plant harvests intended for medical users, and reports such a large difference that he won't go back to an environment without UV-B represented. He said that the patients he supplies reported that they needed 25% less plant product to fulfill their medical needs. The same situation was reported by Alchemy Grower, another medical grower, who feels that it makes such an impact that he will keep the UV-B producing lamp in his growing area. maxgrow_de reported positive results, also, when he said,
The only person to report unvaried results was Sam_Skunkman. He supposedly had his close associate David Pate set up a UV-B experiment in his greenhouse and found no difference between the controls and the UV-B supplemented product, although it was not explained how he tested them. He failed to give the strain used, any procedure, or growing conditions of the experiment; therefore his test is hard to draw conclusions from. (All taken from http://www.overgrow.com/edge/showthread.php?t=414526 )
Out of the five people to have added supplemental UV-B to their indoor growing environments and reported about it, four report an increase in the narcotic properties of their final product. Three felt that there was such a difference that they will not go back to using no UV-B supplementation. Sam_Skunkman reported no difference, although the strain he used and procedure were never reported. aallonharja, despite reporting a positive increase in resin production, felt it wasn't important enough to do again, but that could be due to the fact that he is an extremely experienced cultivator and there was not that much psychoactive difference between his products with UV-B and those without. Now that a direct correlation has been shown between UV-B radiation and the potency of Cannabis, one would suspect more people attempting UV-B supplementation in their indoor environment, with positive results reported.
In support of the fact that Ultraviolet-B radiation positively influences the narcotic properties of Cannabis, one could look at the writings of Ed Rosenthal, an author who specializes in indoor Cannabis growing. He seems to believe that UV-B is important in growing a narcotically potent Cannabis plant. His advice has been taken by more people on indoor Cannabis growing than any other author, mostly from his "Ask Ed" column which appears in Cannabis Culture magazine, or his best selling books on Cannabis growing. There have been at least two "Ask Ed" articles that speak of UV-B radiation, both in a positive light.
The first is from the November 2002 issue of Cannabis Culture in an article entitled "Light Disagreement", where an individual claims that Metal Halide HID lamps are better for the flowering cycle because of the UV radiation emitted by them. The person claims,
In response, while probably speaking of Lydon's dissertation, Rosenthal says,
The second instance of Mr. Rosenthal speaking on UV-B radiation is from the February 2003 issue of Cannabis Culture. In the article entitled "Metal Halide for Flowering?" Rosenthal says,
Mr. Rosenthal's advice should not be taken lightly due to his reputation and widespread audience in the Cannabis growing community.
The scientific data has shown that intense levels of Ultraviolet-B radiation have been the single most important environmental factor in developing Cannabis varieties with highly narcotic properties. The environmental stress of UV-B radiation coupled with the obvious artificial or cultural selection carried out by the human race, has resulted in varieties of Cannabis with large quantities of the psychoactive principal delta-9-THC. It would seem that today, Cannabis breeders are focused mainly on artificial selection, with little or no emphasis on the environmental factors that would affect the cannabinoid biosynthetic pathway, content, and ratio.
The author has no knowledge of modern breeders trying to give their plants an intense level of UV-B radiation, although it would seem that this was the case for cultivators in the distant past. With the amount of high quality, highly narcotic Cannabis strains available today, it would seem that the last step would be to give the plant a supplemental dose of Ultraviolet-B type radiation equal to that of low-latitude or high-altitude environments in order to fully develop the biosynthetic pathway to THC with little or no CBD involved. The lack of UV-B radiation in a Cannabis growing environment would effect the potency of the mind-altering attributes, as in the plant would not be as narcotic as if there was a quantifiable level of UV-B radiation in the light. Highly potent Cannabis can be grown without UV-B radiation being represented due to intense cultural selection, although it would seem that almost all the strains grown today are originally from areas of intense UV-B radiation.
Ultraviolet-B radiation is the single most effective environmental stress to increase the psychoactive potency of Cannabis. In fact, it's evolutionary, and over the years, along with a human hand, it has played the most important role in developing Cannabis with large quantities of its main psychoactive principal, delta-9-THC. The words of David Pate can best conclude this discourse when he wrote,
