[U said:
frmrboi[/U];6623098]too much Kush.
it's all from breeding, UV will only possibly increase the volume of resin not the percentage of THC in it.
The Evolutionary Effects of Ultraviolet-B Radiation on the Psychoactive Potency and Cannabinoid Content of Cannabis sativa L. The Evolutionary Effects of Ultraviolet-B Radiation on the Psychoactive Potency and Cannabinoid Content of Cannabis sativa L.
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,
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The remaining data (Table 1) are assumed to be plants native to their respective areas or introduced long enough ago to be well adapted. (Pate, 1979)
And,
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Higher levels of delta-9-THC are evident in plants from origins of intense UV-B (Fig. 26). Even with the rather non-specific data base used, the results are highly significant (prob. = .0001) and ambient UV-B levels of seed origin account for over 40% (r^2 = .409537) of the observed variation in % delta-9-THC content. As could be expected, there is also a negative correlation between % CBD and UV-B intensity. (Pate, 1979)
This is a rather interesting observation, and one that has been noted by Bouquet,
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In Egypt, when the Viceroy Mehemet Ali wished to create a navy, he got Cannabis seeds from Europe in order to obtain suitable fiber for cordage. New seed had to be brought periodically, because the hemp plants obtained soon became incapable of producing good textile fibers. On the other hand, they began to secrete abundant quantities of the inebriating resin. (Bouquet, 1950)
And,
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Hemp cultivated in the plains gradually loses the property of supplying active resin. (Bouquet, 1950)
Bergel reported similar findings when he wrote,
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When we were still working in this field we were told that the production of active resin, in any kind of Cannabis plant, depends entirely on the altitude of the plantation; for example, you get rich charas or bhang in Northern India
only at a certain height above sea level. It was also reported that in order to obtain active resin one had to plant Cannabis in Germany or near Rosenheim not far from Munich, which again is above a certain altitude. (Bergel, 1965)
David Pate discusses Bouquet when he says,
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The work of Small and Beckstead (1973) has indicated a substantial biosynthesis of (delta-9-THC) in plants originating between 30 degrees North and South latitudes. This is complimented by their observations of high-latitude CBD-predominant strains and an intermediate chemotype from border areas. Is it only coincidence that this pattern follows latitudal increases of UV-B, with the 30 degrees North to 30 degrees South belt exposed to the greatest intensities?
Certain regions somewhat outside this belt that are known for their Cannabis products (including Morocco, Afghanistan, Lebanon, and the Yarkand district of China) raise their crops at UV-B enriched altitudes. (Pate, 1979)
He goes on to say,
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One of the samples that Small et al. (1975) investigated originated from seed of a Mexican strain raised in Mississippi by Turner et al. for NIMH distribution as 'standardized marijuana.' This strain produced only 1.5 % (delta-9-THC) in Canada, about 50% of its content when grown in the more southerly location. ... one might plausibly suspect the ~150% UV-B exposure difference between the two locations (for the increase in delta-9-THC). (Pate, 1979)
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,
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Samples with the highest ratios (of delta-9-THC to CBN/CBD) came from regions whose sunshine was least attenuated by cloud cover, a variable affecting levels of UV-B irradiances. (Pate, 1979)
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,
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Haney: Were the plants you were working with grown outdoors, or under glass?
Miras: Outdoors.
Agurell: In a greenhouse, with U.V. tubing.
Haney: Ultra-violet light is a very important factor. (Joyce and Curry, 1970)
He does hint at the reason why when he says,
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His (Small's) conclusion that there is a strong correlation existing between high-THC cannabinoid phenotypes and cultural selection for potent strains
does not take into consideration that his data also reflects that individuals of phenotype I, considered drug Cannabis, are usually grown south of 35 degrees latitude. (Clarke, 1981)
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,
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Proposed that the two distinct C. sativa chemotypes (delta-9-THC producing, drug type and CBD producing, fiber type) evolved as a result of selective pressures brought about by UV-B radiations. (Lydon, 1985)
In Pate's closing paragraph he says,
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The results of the experiment clearly indicate that individuals of Cannabis have been selected to produce large quantities of (delta-9-THC) in situations of high UV-B exposure. This seems to be the consequence of an advantage conferred by the organism by the UV-B screening properties of this compound. (Pate, 1979)
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,
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... the more intense ambient UV-B radiation of the tropics, in combination with the UV-B lability of cannabidiol, may have influenced the evolution of an alternate biogenetic route from cannabigerol to tetrahydrocannabinol in some varieties. (Pate, 1994)
He explains later, saying,
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Their experiments (Lydon, 1987) demonstrate that under conditions of high UV-B exposure, drug-type Cannabis produce significantly greater quantities of THC. They have also demonstrated the chemical lability of CBD upon exposure to UV-B (Lydon and Teramura, 1987), in contrast to the stability of THC and CBC. However, studies by Brenneisen (1984) have shown only a minor difference in UV-B absorption between THC and CBD, and the absorptive properties of CBC proved considerably greater than either. (Pate, 1994)
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,
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The greater UV-B absorbency of CBC compared to THC and the relative stability of CBC compared to CBD might nominate this compound as the protective screening substance. The presence of large amounts of THC would then have to be explained as merely an accumulated storage compound at the end of the enzyme-mediated cannabinoid pathway. (Pate, 1994)
And also by Bassman when speaking in general of UV-B radiation's effects on plants,
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In addition, some secondary metabolites may increase with enhanced UV-B radiation, whereas concentrations of others may decrease. (Bassman, 2004)
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, a
lthough 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.
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You can determine clear differences in between the UV powered plant and the other two ladies.
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,
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MH lamps produce more (Ultraviolet light) than HPS lamps and the more UV, the higher the potency climbs in normally high potency plants. (Rosenthal, 2002)
In response, while probably speaking of Lydon's dissertation, Rosenthal says,
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A researcher conducted a controlled experiment in a greenhouse. ... He found that the percentage of THC increased in a direct ratio with the increase in UVB light. This research confirms the adage that high altitude plants are more potent than those grown at low altitudes. If you look at old-world land races of Cannabis plants that have become adapted to the climate and latitude, the ratio of THC to CBD starts at 100:1 at the equator. At the 30th parallel (the Hindu Kush Valley) the plants have a ratio of 50:50. At the 45th parallel the ratio is near 1:100. This corresponds roughly with the amount of UVB light received at these latitudes. There is much more UVB at the equator than the 45th parallel. (Rosenthal, 2002)
T
he 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,
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Third, the lamps emit more UVB than HPS lamps, although still in very small amounts. The amount of UVB light plants receive is directly related to the quality of buds. The more UVB, the higher the quality. (Rosenthal, 2003)
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, 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.
UVB/Cannabis science report
Article: UV-B RADIATION EFFECTS ON PHOTOSYNTHESIS, GROWTH AND CANNABINOID PRODUCTION OF TWO Cannabis Sativa CHEMOTYPES.
By: JOHN LYDON, ALAN H. TERAMULA and C. BENJAMIN COFFMAN.
Department of Botany, University of Maryland, College Park, MD 20742, USA.
My estimated conclusion: "Add 3 x 26w UVB lights / m2 to your grow room and increase THC levels up to 30% in buds"
Read this science article regarding UVB lights effect on drug type cannabis originated from high heigted tropical areas with highly elevated UVB levels. In experiments with plants they have shown an increase of THC concentration levels in leaves (glands) from in a range from 22% - 48% depending on UVB intensity. In flower trichomes they got an increase between 15% - 32%. Thats staggering news! Now, this is laboratory conditions with UVB lights filtered to emitt in 300 nm wavelenght UVB light. It's widely known that THC UVB absorption properties range between 280 - 315 nm, so that is important. There's no longer any doubt in my mind that UVB boosts the THC potency of drug type cannabis, and that dont having UVB light is not realising the full potential of our dear plants!
Environmental Influence It takes high quality genetics to produce high quality marijuana, but genetics is only half of the equation. The genetic structure (genotype) only plays 50% of the role in determining the appearance and quality (phenotype) of a given plant. The other half is determined by environmental conditions such as light, temperature, humidity and soil nutrition. All these factors play a role in both the physical and chemical nature of marijuana's trichomes.
The best way to take a look at how environment affects THC production is to look where on the planet cannabis has naturally adopted a high THC profile. As cannabis has spread around the world it has taken on many different traits to help in its adaptation to varied areas.
The best drug varieties have always been found at equatorial or high altitude locations. The one thing which both of these variables have in common is high light intensity and a large amount of ultraviolet (UV) light in the spectrum.
Recent Swiss trials in outdoor plots of clones grown at different altitudes have shown that there is correlation between higher altitude and increased potency (although there seems to be a trade off in yield). This likely means that THC-rich resins act to protect the plant and its seed from both higher light intensities and ultraviolet presence. It's no surprise that cannabis has developed a chemical to protect itself against the Sun's damaging UV rays, as they can be injurious to all forms of life.
In a plant's search for survival, energy put towards unneeded processes is wasted energy. Therefore a high-THC plant grown in a low THC environment will likely produce a medium THC result.
