UVB bulbs...

[Sam_Skunkman]

Its a well proven fact currently that both CBD and THC uses same compound (CBG) as precursor. And that that partition is determined genetically.

But its too well proven that same genetic may have different potency if grown in different environment, although always with a generic baseline.

So there is some effect of environment over how work each synthase (of THC(A) and CBD(A)). We dont know absolutelly nothing about how this works, although is pretty reasonable it works by epigenetics.

Recently has been proven that epigenetics are heritable at some degree. It could give base to the old claim of Pate about cannabis not only adapting to environment, but transmiting such adaptation to descendence. There has been little work on this topic, so we dont know what is the margin of epigenetics modulating gene's expresion and its time course.

How much it take for the plant to adapt? We know how much time cannabis takes to adapt to a new lighting spectra, by changing light absorbing pigments (chlorophill a and b, carotenoids, etc) to absorb more of the new light: about a week. If responses to UV are so fast, it would be great. But i suspect this adaptation is longer for the biochemical THC pathway.

Im more interested on effects of UVB on breeding than its inmediate effect on a live plant.

Would two parents grown on a high UVB environment produce seed genetically programed to produce a profile higher in THC? (than when not grown at that environment).
SamS, do you think is worth exploring this possibility?

Maybe, but this is beyond my scope of work. And I am not much of a believer in phenotypical changes affecting genotypical expression.

"But its too well proven that same genetic may have different potency if grown in different environment, although always with a generic baseline.
So there is some effect of environment over how work each synthase (of THC(A) and CBD(A)). We dont know absolutelly nothing about how this works, although is pretty reasonable it works by epigenetics."

Why does it have to involve epigenetics? And I think that the environment is more involved if the environment somehow prevents flowering or full maturation, like the case of trying to grow a late Sativa outdoors in a northern latitude. I know of no work that suggests epigenetics is involved with modulating Cannabis synthase's, do you?

-SamS

 

[Miko]

SamS, could you please drop a few words abut seeded plant resin vs unseeded? Good luck with R&D friend!

 

[knna]

Maybe, but this is beyond my scope of work. And I am not much of a believer in phenotypical changes affecting genotypical expression.

"But its too well proven that same genetic may have different potency if grown in different environment, although always with a generic baseline.
So there is some effect of environment over how work each synthase (of THC(A) and CBD(A)). We dont know absolutelly nothing about how this works, although is pretty reasonable it works by epigenetics."

Why does it have to involve epigenetics? And I think that the environment is more involved if the environment somehow prevents flowering or full maturation, like the case of trying to grow a late Sativa outdoors in a northern latitude. I know of no work that suggests epigenetics is involved with modulating Cannabis synthase's, do you?

-SamS

I dont, too. I dindt find any work about this topic. Its just an hypothesis (thats why i wrote "reasonable") and asked for your opinion about it.

But studies about epigenetics are relativelly new, and the limitations working on MJ does very difficult researchers choose it to study this topic.

But the fact is we know very little about the ways environment affects cannabinoids profile. For example, the question arised by Miko. Why and how unfertilized Mj is more potent? Its only that more resin is produced? Or partition between CBD and THC changes too?

From what ive read, both things happen. As by far the higher tricomes density occurs at flower's bracts, and they are higher in percentage of THC against other cannabinoids at that part of the plant than in leaves, it may be hypothesized that the role than resin in general, and THC in particular, may be related to fertilization. Some botanist have suggested that it improves polenization by insects. Others has suggested it plays a role of protection against them and hervivores: for example, an infestation of spider mites make the plant produce more potent resin.

This last hypothesis is somewhat linked to the UV hypothesis, as most insects are atracted by UV wavelenghts. Its the increase of potency result of plant sensing insects activity on it?

The 3er hypothesis about resin and THC role in cannabis is it photoprotect plants form excess UVB. Im not sold with this idea because in that case, there is little sense on less concentration on leaves. But it could explain why there is THC too in the inner parts of the leaves (although in small quantities).

So we need a lot of research about all this in order to learn ways of improving Mj potency (and other cannabinoids), both on ways of growing and breeding.

I was researching about light influency on cannabinoids, but ive found that i need a way to test cannabinoids profile to get any meanglifull conclusions. But my equipment is limited to a spectrorradiometer. Anybody knows a way of profiling cannabinois with it? (without investing on a gas flow device). Im thinking on exploring absorbance peaks on the UV range, but on liquid samples of cannabinoids extracts. Any suggestions about this are greatly apreciated


Peace,
knna

 

[Sam_Skunkman]

About seeded vs unseeded, yes there is more resin in an unseeded plant, and the resin is higher in terpenoids. Making seeds is a lot of work for the plant. The ratio between the THC and CBD if any does not change. I doubt resin improves pollenation, the insects
don't need to pollinate Cannabis it is wind pollinated and the insects get all stuck in the resin and die. I don't suggest infesting plants with spider mites to get a bit more resin, I like big healthy plants, not smaller insect infested plants.

-SamS

 

[Londinium]

I myself have also given up on the Idea of UV having a major effect indoors 4 me after trying various bulbs and wattages of additional UV lighting in the past and more recently.
I use mixed 4 to 1 HPS(agro)/MH in my flowering rooms and get the best quality harvest that way compared to straight HPS,after trying various combo's.
I continue to use the HPS/MH because it helps keep internodes shorter during flowering cycle as`well as veg cycle and seems to up the apparent terpenoids...I assume due to more action in blue/white spectrum and nowt to do with UV as I use air cooled(with glass ) reflectors,which apparently block most UV anyhoo(removing glass just led to hotter plants with lower potency)!
I find changing the angles(Haze's espesh),timing(MH only in morning?),dimming(in my experience some mountain indica's like a few artificial Cloud-covers during day cycle),intensity(more lights on middle of day for best D.Poison) and movement(slow light mover on day cycle) of your lighting has more benefit for tailoring to diff strains needs(espesh difficult Sat's)and therefore acheiving perceived peak potency,than any change of spectrum searching for UV's Holy Grail of Extra Resin will do.
My indoor plants have plenty of resin and potency under HPS through glass but I agree Tastiest,strongest things I've smoked were Primo Outdoor buds and their Hash ,But I don't think its got so much to do with UV. JBo@URBN-TRCHMLGY

 

[onegreenday]

flaw in Joe Knuc chart

flaw in Joe Knuc chart

From Joe Knuc's Marijuana Optics:

(b)"The maximum UVB irradiance near the equator (solar elevation angle less than 25 deg.) under clear, sunny skies is about 250 µW/cm2. It was observed that the daily solar UVB in Riyadh, Saudi Arabia (N24.4Lat.) decreased from September to December by about 40% (Hannan et al. 1984). The further a person is from the tropics, the less UVB radiation there is: the average annual exposure of a person living in Hawaii is approximately four times that of someone living in northern Europe." Below are some UVB readings taken in Hoyleton, Illinois, on a clear sunny day in June by David Krughoff as reported in Reptile Lighting 2000.

7am: 12 microwatts/cm2
8am: 74 microwatts/cm2
9am: 142 microwatts/cm2
10am: 192 microwatts/cm2
11am: 233 microwatts/cm2
12pm: 256 microwatts/cm2
1pm: 269 microwatts/cm2
2pm: 262 microwatts/cm2
3pm: 239 microwatts/cm2
4pm: 187 microwatts/cm2
5pm: 131 microwatts/cm2
6pm: 61 microwatts/cm2
======================

according to this chart 256 microwatts at noon in Hoyleton, IL , in June

but a maximum of 250 microwatts near the equator at less than 25 deg.

more microwatts in IL; that does not seem correct to me.

what's up with that?

 

[lokes]

Okay, so what is the consensus here? I've learned that using a UVB increases trichome production and the 320nm spectrum is important. However, the authority seemed to say He wouldn't use it as it is dangerous and ages everything when the right spectrum is used.

So have we concluded that the harmful effects outweigh the benefits? or using one with less UVB in the 320 spectrum (ie- reptile light) is better than no UVB at all.

 

[Hydro-Soil]

Can UVB be used to grow large trichomes and then turned off?

Can UVB be used to grow large trichomes and then turned off?

Can UVB be used in the beginning of the grow to induce the growth of many trichomes and then be turned off?

Is the length, width and head size affected by exposure to UVB?

Does this length, width and head size remain constant, even if the UVB is then removed?

Does the diameter of the head change the wavelength of UVB needed to properly convert what we don't want into what we want?


The amount of UVB a plant recieves during it's life cycle does not stay constant and even begins when it is a seedling. Given this fact I would assume that the plants would do better if exposed to UVB more during the seedling/clone/veg stage before going into flower than when used throughout just the actual flower.

So to would the normal drop in UVB, for outdoor grows, be indicative that less UVB is needed in the later stages of flower?

I'm still trying to process everything in this thread as I research for my long term sativa box. (looking to pick up some 6 month flowering sativas if possible) There is quite a bit I still have to keep going over.


Thanks for all the great info so far.

 

[Ran]

Can UVB be used in the beginning of the grow to induce the growth of many trichomes and then be turned off?

Is the length, width and head size affected by exposure to UVB?

Does this length, width and head size remain constant, even if the UVB is then removed?

Does the diameter of the head change the wavelength of UVB needed to properly convert what we don't want into what we want?


The amount of UVB a plant recieves during it's life cycle does not stay constant and even begins when it is a seedling. Given this fact I would assume that the plants would do better if exposed to UVB more during the seedling/clone/veg stage before going into flower than when used throughout just the actual flower.

So to would the normal drop in UVB, for outdoor grows, be indicative that less UVB is needed in the later stages of flower?

I'm still trying to process everything in this thread as I research for my long term sativa box. (looking to pick up some 6 month flowering sativas if possible) There is quite a bit I still have to keep going over.


Thanks for all the great info so far.

I've never tried this so don't really know, but from reading the thread I thought UVB would have no effect on size/shape/number of trichs. Only the amount of THC in the trichs?

 

[Hydro-Soil]

I've never tried this so don't really know, but from reading the thread I thought UVB would have no effect on size/shape/number of trichs. Only the amount of THC in the trichs?

The reason I ask is that I can get a plant to frost up killer under CFLs in my Mum/Veg chamber. They also frost up really nice under the HPS but the CFLs seem to make a difference.


Since I read so much about how extra frosty stuff gets under UVB I was just wondering.

Maybe I'm just off-base here

 

[lokes]

I've never tried this so don't really know, but from reading the thread I thought UVB would have no effect on size/shape/number of trichs. Only the amount of THC in the trichs?

Just the opposite actually. It increase the amount of Trichs per surface area. Thus the THC isn't stronger, just more of it by default. The only problem is it needs to be in the 320nm spectrum which I understand Lizard Lights don't have much of. There are some good threads here on the subject just do a search.

 

[Ran]

Just the opposite actually. It increase the amount of Trichs per surface area. Thus the THC isn't stronger, just more of it by default. The only problem is it needs to be in the 320nm spectrum which I understand Lizard Lights don't have much of. There are some good threads here on the subject just do a search.

Ah, ok thanks for clearing that up

 

[earthbob]

I have done a comparison of a white widow cutting grown under a 26W Repti Glo 10.0 cfl versus a cutting from the same mother under a 26W warm white cfl. HPS lighting was supplemental to both clones. The cutting under UV ripened about one week earlier but smoked the same as the other clone. For those of you who feel that uvb makes more THC, I ask if perhaps the uvb weed was better because it was riper?

 

[dontstepongrass]

wow! this thread is still alive lol.

earthbob - since what we know about uvb aging things at an accelerated rate as compared to no uvb, your ? may have some merit...

lokes - as to your concern with finding lights that lack that particular wavelength, i believe the answer will present itself in the next few years. uvb led's are not widely available (if available at all) at the moment, but i have a feeling they may be around the corner as everything is eventually phased over to led. once that is done, it is just a matter of soldering arrays of the leds (of the proper wave lenghts) onto a board

 

[earthbob]

dontstepongrass, the results of my own testing have been clear enough to me that UVB is not worth it. I do not however, discount the possibility that others may notice improvements where I did not. I wish that I had a bunch of stoner friends over who could give me their opinions of the smoke, but so far we have to rely solely on my palate. I have to admit that I am rarely able to discern different flavors in a fine Merlot and I consider those who say they detect a hint of raspberry to be wine snobs. Same thing with pot. I know good pot when I smoke it but some of these exotic descriptions that people give for the type of high they are experiencing make me think of the wine snobs.

 

[cktRAVEl]

...

 

[earthbob]

uvb is dangerous and not very many photons per dollar. I doubt that commercial growers would use uvb solely for the purpose of an earlier harvest.

 

[inefectualize]

im too lazy to read the whole thread so if this link was already posted please ignore

http://www.reptileuv.com/megaray-products.php

 

[sunnydog]

I agree. I have used considerable amounts of UVB and have seen no improvement. I will not bother with it again.

dontstepongrass, the results of my own testing have been clear enough to me that UVB is not worth it. I do not however, discount the possibility that others may notice improvements where I did not. I wish that I had a bunch of stoner friends over who could give me their opinions of the smoke, but so far we have to rely solely on my palate. I have to admit that I am rarely able to discern different flavors in a fine Merlot and I consider those who say they detect a hint of raspberry to be wine snobs. Same thing with pot. I know good pot when I smoke it but some of these exotic descriptions that people give for the type of high they are experiencing make me think of the wine snobs.

 

[cktRAVEl]

uvb is dangerous and not very many photons per dollar. I doubt that commercial growers would use uvb solely for the purpose of an earlier harvest.

Really? Just a thought...if a person could harvest every 6 weeks and and get almost the same quality high as letting it go 8. Obviously you lose some weight....lets say you lose 20%. But you gain 2 harvests per year. That gives you an overall increase of 6.7% for the year.

As far as uvb danger goes...not to belittle it, but I think its negligible, as long as the appropriate precautions are taken.

peace...ckt