Gw Pharmaceuticals Supported Thesis On Growing

[in vivo]

THE PROPAGATION, CHARACTERISATION AND OPTIMISATION OF CANNABIS SATIVA L AS A PHYTOPHARMACEUTICAL

A thesis submitted by
David Potter JP
MIBiol CBiol FLS CMIOSH

 

http://doczine.com/bigdata/1/1367127078_99940c8889/phd_david_potter_jp.pdf

Edited March 9, 2014 by in vivo

[in vivo]

Nobodies into reading three pages of information only to come to the conclusion that the 12hr dark period is the most effective flowering strategy? lol

[t-pain]

the thesis acknowledges that a lot of medicine is plant derived.

 

 

The suspected 1:1 THC:CBD ratio in UK
cannabis was based on research into the cannabinoid profile of illicit material in the
USA.

 

they dont cite where they get the 1:1 data.

i wonder if its from that same place that said in sanjay's video about the 36% thc material existing...

(aka they made it up)

 

the siezed samples they analyzed prove the 1:1 data was moo poo,

unless usa ditchweed from mexico is that different from the afghani ditchweed in the uk?

most are 10:1 thc:cbd ratio or worse. except for resin(hash) which contains about 1:1.2 ratio of thc to cbd.

 

ah! gw pharm is growing seeds from the banks and testing the thc!

 

gw pharm says that marinol is inferior to the real plant.

 

it says male flowers have a kind of trichome not found on the female plants.

might be useful to mix the male flowers into your finished product ?

 

darn. it looks like the color of the trichs doesnt affect the cannabinoid %..

going to have to come up with some other way to test potency.

 

gw pharm made ice hash with a blender:)

 

 

someone is going to have to explain page 93 to me.

it looks like they got a higher percentage from a 3 week plants leaves than an 11 weeks plants flowers?

maybe there is less material?

 

 

 

The results of the cannabinoid assay suggest that both cultivars had
reached maximum potency at the end of the seventh week in short daylength.

so gw pharms strains work best after 3 week veg and 7 weeks of flower.

of course, 'best' is determined by terpene and cannibinoid % from chemical analysis, not patient surveys.

 

so unfortunately this only tells us the peak time to harvest for peak %, not the peak time to harvest for best results.

[t-pain]

i'll get to reading the rest of this (255 pages, only 120 pages to go) later.

Edited August 24, 2013 by t-pain

[in vivo]

Thanks for joining the conversation. I'm gonna have to read this more thoroughly. I browsed through it mostly.

 

they dont cite where they get the 1:1 data.

i wonder if its from that same place that said in sanjay's video about the 36% thc material existing...

(aka they made it up)

 

the siezed samples they analyzed prove the 1:1 data was moo poo,

unless usa ditchweed from mexico is that different from the afghani ditchweed in the uk?

most are 10:1 thc:cbd ratio or worse. except for resin(hash) which contains about 1:1.2 ratio of thc to cbd.

 

page 17:

 

Studies in the USA had shown that cannabis resin (hashish) typically contained approximately equal quantities of both cannabinoids, whereas herbal cannabis (marijuana) contained predominantly THC (ElSohly et al, 1984).

 

I haven't read or looked up the citation, but given that CBD is more stable than THC, one explanation might be that the sample was old. Additionally, if it's a citation from '84, we're talking about much lower THC percentages to begin with.  

 

I'll take a look at page 93 now.

Edited August 24, 2013 by in vivo

[in vivo]

Over half of all known drugs work through G-protein receptors (Alberts et al., 2002).

 

^^ Not grow related, but an interesting tidbit nonetheless.

[t-pain]

 

A sufficiently deep

hole is prepared in this medium to allow the seedling to be lowered undamaged so that

the first pair of true leaves sat 1-2 cm above the surface of the medium.

 

i think someone said roots can form on the cannabis plant up until the first true leaves.

so plant your plants deep!

 

gw pharma used bugs to eat the spider mites, thrips and white flies.

 

 

THC

degrades more rapidly in the presence of light (Fairbairn, 1976).

keep your meds in a dark place.

 

gw pharma takes clones before knowing sex. then discards male clones.

 

 

The yield of raw material obtained from plants grown from seed (494 g m ) and

cuttings (515 g m ) was very similar.

quanity is the same, seed vs clone in same environment. 

 

 

 

However, the mean THC content of the

cloned plants (14.6% THC w/w) was significantly higher (ANOVA, p < 0.01) than those

grown from seed (11.1% THC).

i dont know if this means the seeds they chose were only 11% ?

 

 

winter crops yielding less than those grown in summer.

more light = more thc.

 

mercury vapor lights suck compared to mh and hps.

when light bulbs dim, cannabis yield goes down. yep.

 

ooh.

 

This suggests that

the irradiance conditions at the very beginning of flowering have the greatest potential

impact on the final yield.

 

so add more lights the first few weeks of flowering and you get bigger yields!

bingo! this is important.

 

 

 

The clones that clearly benefited from a longer ten week flowering period were

generally those reported to have an equatorial and subequatorial areas provenance. In

their natural habitat these would experience a longer growing season.

5 out of 25 strains gw pharma tried get more thc with 8 weeks vs 10 weeks of flower.

what i think it means is that in 5 strains , the thc degrades if it is given an extra 2 weeks.

but some of the strains get way more (50% even) thc from those extra two weeks. those must be sativas?

 

12 hours is best, 11 hours was bad and 13 hours showed different results with different strains.

 

 

However, both crops

encountered fungal spoilage by Botrytis in the last week before planned harvest.

outdoor got budrot

 

 

Rabbits caused extensive damage to a crop planted

in 2001

wheres wallace and gromit when you need them? curse of the were-rabbit!

 

 

74% of Sativex patients achieved an

improvement in their spasticity score over the entire study versus 51% on placebo

 

darn placebo rocks!

 

and thats it. lemme know if theres anything i missed.

[in vivo]

I've yet to thoroughly go through the rest. I'll spend some more time reading it today. 

 

One thing that stands out at me is being able to identify high CBG plants by viewing the trichomes of plants in veg. High CBG plants had cloudy trichome heads after the first few weeks of veg.    

 

(edited to change CBC to CBG)

Edited August 29, 2013 by in vivo

[Chauncy Gardner]

After reading this, I now believe that the "pros" could do a bang up job of growing cannabis and further research will only bring more positive benefits to the growing community.

 

I would definitely get in line to try some "Pro Grown Cannabis".  Think we will ever see it?

[in vivo]

If quantitative analysis were more widely available and cheaper, it seems to me as if our knowledge of how to maximize cannabinoid content would explode (via the online community).

 

I also think that once more breeders begin utilizing quantitative analysis, and genotyping by PCR, that we'll see a rapid advancement in the average growers ability to maximize the delivery of therapeutic properties from their strains.

 

I hope we'll see both happen in the near future.  

[in vivo]

6% of orally consumed THC becomes bioavailable. (I've seen varying numbers on this)

 

They claim this paper from the 70's is one of the most comprehensive on trichomes. 
 

Recent research shows that CBGA, the biosynthetic precursor of THCA and other cannabinoids, and THCA synthase enzyme are found within the secretory cavity (Sirikantharamas et al., 2005). This suggests that the secretory cavity is not just the site for the accumulation of cannabinoids, but also the site of THCA biosynthesis.

 

^^ This makes me want to investigate the effect that UV-B has on cannabinoid content. I've even seen some papers documenting after harvest treatment with UV-B to increase sought after constituents, from unrelated crops.

 

sessile trichomes, which have been shown to have a higher proportion of CBC to capitate stalked trichomes of the same age

 

^^ They caught a higher percentage of CBC in their 25um screen.
 

The trichome on this sieve contained a higher proportion developed within the first weeks of growth when the proportion of CBC within the whole plant was much higher

 

^^ This might be a feasible way of procuring CBC. (Find a strain with a large number of sessile trichomes in the first few weeks of veg, then use bubble bags to concentrate.) 

 

Cannabinoid profiles of younger plants will also have higher percentages of CBG.
 

from this test it was important to note that separating trichomes with sieves appeared to offer a means of producing phytopharmaceutical feedstocks with a favorably altered cannabinoid profiles

 

important to note, that in some cases, a range of terpenes can be synthesised with the involvement of a single enzyme (Croteau and Johnson, 1984). As a consequence, the ratio of the terpenes produced always maintains a fixed ratio. α-pinene, β-pinene and limonene, may be linked in this way while myrcene appears not to be linked to other terpenes.

 

This is might be useful for attempts at mimicking cannabis terpene profiles with add back programs of essential oils/terpenes.

 

The chart on the percentages of terpenes from one week to the next is interesting, but I wish they would have tested each week. They test week three and then skip ahead to nine. The terpenes are highest for this chemotype in week ten, but they're high in week nine. It makes me wonder if flowering for 2-4 weeks and using steam distillation to capture the terpenes would be a feasible way of capturing a plants exact terpene profile. I wish I could test for terpenes..

 

The remarkably unchanging cannabinoid and terpene profiles, from the eighth week of the flowering period onward, suggest that the secondary metabolites are stable while sequestered in the trichome.

 

In many cases these monoterpenes are repellent to insects, (e.g. α-pinene and ants)

 

Have any ant problems? (On an unrelated note Met25EC is a bioinsecticide worth checking out. Ever see the

?)

 

I'm not going to be able to get to it tonight but it might be worthwhile to read GW's patent on a simple method of isolating and purifying CBC.
 

Gotta take a break..

 

Edited August 29, 2013 by in vivo

[in vivo]

Growth media had to be developed that supported good root development, and fertilizer regimes had to be devised to give the correct balance of nutrients at the appropriate time in the plants’ development. As the results of these studies are also of interest to illicit cannabis growers, this aspect of the research cannot be included in this thesis.

 

^^ What a jip.

 

the plant is responding to the increasing length of the night, during which time a light-sensitive phytochrome protein slowly dimerises to a different form. Within seconds of light exposure the protein reverts back to the original structure.

 

^^ This is why all flowering rooms should have green lights.

 

 

crops were spaced at a density of 10 m-2 (THC chemotype) or 17 m-2 (CBD chemotype)

 

^^ Their CBD chemotype is a sativa?

 

These were controlled by regular introduction of the predatory mite and insect species Phytoseilius persimilis, Amblyseius cucumeris, Encarsia formosa and Aphidius colemani (Malais and Ravensberg, 1992).

 

 

^^ I know you commented on this, but I'm not sure if you posted the quote.

 

Glasshouse temperatures and lighting conditions were controlled by a Priva Universal Computer (907) system.

 

^^ Anyone ever use an automated system that records your environmental conditions? 

 

In addition to clones specifically bred to produce a mixed THC/CBD profile, one was discovered by chance (code name G159) while screening plants grown from commercially available seed.

 

^^ This goes to show that finding chemovars with the THC/CBD profile isn't that uncommon.

 

The yields achieved in the first full year of crop growth in a solid building with no natural lighting were similarly monitored. Yields showed a downward trend, commensurate with the manufacturer’s predicted age-related fall in irradiance from the lamps.

 

^^ Change your bulbs!

 

Edited August 29, 2013 by in vivo

[in vivo]

This suggests that the irradiance conditions at the very beginning of flowering have the greatest potential impact on the final yield.

 

You commented on this. I wanted to add that it makes sense when you think about stretch and N. More mass, more THC. 

 

The data on the differences between 12hr and 13hr flowering seems to indicate that some strains (likely sativa dominant) will produce much more under 13hr days rather than 12.

 

Harvested eight or ten weeks after being placed in a twelve or thirteen hour daylength, all ten clones had a proportionally higher CBG content if grown in the thirteen hour regime

 

^^ I don't think anyone is rockin a CBG dominant chemovar, but it still seems worthy to note.

 

Conversely plants in the thirteen hour regime possessed proportionally less THCV

 

 

this investigation concluded that stigma senescence is not useful for judging the cannabinoid content of crops grown for pharmaceutical purposes

 

 

Eleven or thirteen hour daylength regimes are less economical in producing cannabis for the production of cannabinoid-based medicines than the twelve hour regime initially adopted. Future research to explore small adjustments to the adopted twelve-hour regime may be beneficial. Research with ornamental pot-grown chrysanthemums (short day plants) has shown that adjustments of just ten minutes to the daylength can have a dramatic effect on the economic value of the plants produced (Langton and Fuller, 2001).

 

I disagree with the assessment about 13hrs. They're looking for uniformity and an average. Their data clearly indicates that a number of plants they ran did much better with 13hr flowering days than 12hr. 

 

The last part of that makes me wonder about trying to mimic the natural daylight period based on the landrace origin of a particular strain. Good thing tracing lineage is easy..

 

Probably gonna have to finish the last two chapters later.

[in vivo]

someone is going to have to explain page 93 to me.

it looks like they got a higher percentage from a 3 week plants leaves than an 11 weeks plants flowers?

maybe there is less material?

 

That's part of their discussion on extracting CBC from vegetative plants with bubblebags. 

 

of course, 'best' is determined by terpene and cannibinoid % from chemical analysis, not patient surveys.

 

so unfortunately this only tells us the peak time to harvest for peak %, not the peak time to harvest for best results.

 

 

I think I would argue that knowing the cannabinoids and terpenes you're looking for, and knowing their peak times, will harbor the best results.

[Dlo]

Quote

 

the plant is responding to the increasing length of the night, during which time a light-sensitive phytochrome protein slowly dimerises to a different form. Within seconds of light exposure the protein reverts back to the original structure.

 

^^ "This is why all flowering rooms should have green lights."

 

 

can you explain more on this?

 

 

Thanks for the breakdown on this guys, good stuff.

[in vivo]

In the patent they claim to have found a CBD/CBC chemotype from an Afghan hashish landrace. They also found a THC/CBC chemotype from a Korean fibre landrace.

 

Their CBD (91%) chemotype is: (afghan x skunk) x (haze x skunk)

 

Their CBG (82%) chemotype is: (afghan x skunk) x S Italian fiber hemp

 

They outline their breeding program in detail.

 

They're isolating the sessile trichomes to get CBC.   

 

They took 178 plants from a "variety of sources" and extracted CBC from them in veg. They found that CBC was the highest cannabinoid in 4.5% of samples, and the second in 78%.

 

This might add another cannabinoid to my medicine cabinet.

[in vivo]

Quote

 

the plant is responding to the increasing length of the night, during which time a light-sensitive phytochrome protein slowly dimerises to a different form. Within seconds of light exposure the protein reverts back to the original structure.

 

^^ "This is why all flowering rooms should have green lights."

 

 

can you explain more on this?

 

 

Thanks for the breakdown on this guys, good stuff.

 

It's an assumption on my behalf, that this is one of the factors that stresses a plant into throwing nanners. I never realized that it only takes seconds of light exposure. It's likely why green lights in flowering rooms are important in situations that require access to the room during dark periods.   

Edited August 29, 2013 by in vivo

[in vivo]

 

Quote

However, the mean THC content of the

cloned plants (14.6% THC w/w) was significantly higher (ANOVA, p < 0.01) than those

grown from seed (11.1% THC).

i dont know if this means the seeds they chose were only 11% ?

 

That was part of their study comparing a seed crop to the clone crop. The clone crop was only slightly higher in weight, but statistically higher in cannabinoids.

[in vivo]

60% of the terpenes in the outdoor strain (G5 M16) that they run is b-myrcene and b-caryophyllene. (This is their CBD strain I think)

 

They recommend processing prior to drying in order to capture the greatest amount of terpenes possible.

 

The 2006 trial compared of the terpene profiles of field grown cannabis plants harvested at weekly intervals between 17th September and 15th October. This was achieved by first steam distilling an enriched trichome preparation made from fresh botanical raw material collected on each date. Between 30 ml and 100ml of enriched trichome preparation was produced from each, but this contained a large unmeasured volume of residual water. It is not possible to quantify the essential oil concentration of each sample on the basis of the non-aqueous fraction only. When distilled these produced between 0.25 ml and 2.1 ml of essential oil

   

^^ This is sounding more and more like a realistic way of capturing terpenes from cannabis.

 

In a separate study not reported here, where these clones were grown in a growth room in identical conditions apart from contrasting growth temperature of 15ºC and 25ºC, the cooler temperature significantly increased the proportion of CBD within the cannabinoid profile.

 

^^ That might be useful information for anyone growing CBD strains.

 

At room temperatures THCA is an oil and CBDA is a crystalline solid.

 

Fun fact.

 

Lydon et al. (1987) showed that UVB radiation significantly increased THC biosynthesis, whereas CBD biosynthesis did not show a significant increase. However, Lydon et al. (1987) did not show the actual CBD data and did not include a test of the statistical significance of the difference in biosynthesis of THC and CBD when exposed to increasing UVB radiation.

 

I'm buying some UVB lights.

 

I think that about covers it. Pretty good read and applicable information. 

[Ms Chocolate]

Without reading, I bet the bottom line is that GW needs for marijuana to be legal so they can market in the US

[in vivo]

This is some guys thesis who had access to GW Pharmaceutical. I'd say it has more to do with standardizing the cultivation process of cannabis for the production of cannabinoids.

 

I'd say some of the most important information would include:

 

 

• CBG chemovars can be identified by viewing the trichomes in veg
•  
• Plants in veg are high in CBC/CBG
•  
• CBC/CBG rich extracts can be procured via bubblebags
•  
• Info about their breeding program and genetics that went into their strains
•  
• An 8% increase in lighting during flowering (13hr days) can result in over a 25% increases in production for sativas  
•  
• Terpene profiles for their strains
•  
• Using steam distillation to capture terpenes
•  
• You can increase the CBD content by lowering the temperature during flowering
•  
• You can increase THC content by using UVB lighting

 

 

If it's a marketing ploy, I wish they would do some more marketing.

[t-pain]

 

This is some guys thesis who had access to GW Pharmaceutical. I'd say it has more to do with standardizing the cultivation process of cannabis for the production of cannabinoids.

 

An 8% increase in lighting during flowering (13hr days) can result in over a 25% increases in production for sativas  

•  

 

i think i'm more interested in this:

 

#1 more light power at the start of flowering = higher potency yields. (pg 123)

 

This suggests that the irradiance conditions at the very beginning of flowering have the greatest potential

impact on the final yield.

The increased potency of plants grown in

brighter conditions observed in this study

 

which means you can throw a few extra lights on your plants for 2 weeks at the start of flowering and get big results.

then switch the extra lights off and save some electricity.

 

i wonder if someone can duplicate their findings?

 

i guess have two clones.

start one clone in flower with 800W and then after two weeks turn off one light to 400W until harvest.

start one clone in flower with 800W and keep 800W until harvest.

[in vivo]

I think it makes sense that extra lighting during the stretch period of flowering, will result in more foliage and bud sites, which results in more cannabinoids. I suspect that CO2 would achieve similar results during this period, for the same reasons.

 

That being said, I think that you have to take into account how much light you're delivery per square foot. What is the maximum amount of light that cannabis can use? I think that the info they're quoting on page 123 is with supplemental lighting in a greenhouse. Their HPS lighting amounts to 55w/sq meter. If you're rocking 100w/sq ft, you might not see such substantial gains. 

 

Maybe an experiment with two 400w HPS lights during stretch, and finished with one 400w, compared to a single 600w hps grow, would be a closer comparison?

[in vivo]

http://doczine.com/bigdata/1/1367127078_99940c8889/phd_david_potter_jp.pdf

[cheapshades]

http://www.scribd.com/doc/208505274/Final-Full-Thesis-Dj-Potter