brown_thumb
Active member
If UV light stimulates trichome production then why do I consistently see more sugar on deep inner leaves completely shaded from light?
-
Happy Birthday ICMag! Been 20 years since Gypsy Nirvana created the forum! We are celebrating with a 4/20 Giveaway and by launching a new Patreon tier called "420club". You can read more here.
-
Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!
If UV light stimulates trichome production then why.....
- Thread starter brown_thumb
- Start date
The plant doesn't just produce additional trichomes where the light shines. The light isn't producing the additional trichomes directly.
The plant produces more trichomes, all over, because the plant is healthy and thriving. It is thriving (at least in part) because of the uv light.
Uv does produce more trichomes, but the effect is indirect.
The plant produces more trichomes, all over, because the plant is healthy and thriving. It is thriving (at least in part) because of the uv light.
Uv does produce more trichomes, but the effect is indirect.
Lost in a SOG
GrassSnakeGenetics
The effect is on a genetic level. UV activates important genes for plant maturation.
Any scientific background supporting that?
I've read a lot about UV in growing weed and I've found contradictory results.
The idea proposed is not so much the increase in the density of the actual trichomes. The idea is that use of uvb will result in higher production of thca in the trichomes.
I too have noticed flowers on the bottom seem too have better terpene content and higher trichome coverage sometimes. I think that happens to me when hps is too close to tops, and the ir heat is impacting the top parts of plant in subtle negative ways, i.e, maybe fewer trichomes, definitely lower terpenes.
I too have noticed flowers on the bottom seem too have better terpene content and higher trichome coverage sometimes. I think that happens to me when hps is too close to tops, and the ir heat is impacting the top parts of plant in subtle negative ways, i.e, maybe fewer trichomes, definitely lower terpenes.
Lost in a SOG
GrassSnakeGenetics
Yes but its a bit complicated as published cannabis research is still lacking a bit and loads of people have thought UVs to be a holy grail and kind of applied them wrong.
If you search for genetic effects of uvs on plants on ncbi.com you'll find lots of research in this field, imo the research on other plants is applicable to cannabis. It is widely proven and acknowledged that in all plants that produce terpenes/phenols/flavonoids/alkaloids etc protective secondary metabolite substances (which i think is all plants?) uvs induce epigenetic changes that increase a range of antioxidant protective substances based on the intensity of the spectrum at different bands. It appears from a glut of studies the UVs modulate the terpenes based on which absorb at the exact spectrum you are hitting them with.
If you know the absorbance spectra of the terpene you want you can increase it by getting diodes that hit that peak because the plant upregulates its synthesis obviously. This will come at a cost to energy going into other terps. Basically one of the big differences between ganja grown outside in different parts of the world. Like that amazing hawaiian weed, anyone ever thought about passed on genetic changes from that lovely Hawaiian sun and sunsets..
Cannabis isnt very different at all from basil or thyme or rosemary, mint etc etc in this regard.
Also the far red and infrared spectrum delivered in the dawn light helps plants use the UVs throughout the day without being harmed as much or at all.
Honestly I rarely run around providing research for anyone.. ive done too many courses and it triggers me to be forced to provide research papers for someone.. fucking dissertations..
St. Phatty
Active member
I would bet $$ (but I get better odds, since I'm going out on a limb) that the trichomes have multiple functions.
One - the Trichomes help cool the plant. The plant has its own pin-fin heat exchanger.
And, the stickiness helps trap pollen.
One - the Trichomes help cool the plant. The plant has its own pin-fin heat exchanger.
And, the stickiness helps trap pollen.
Douglas.Curtis
Autistic Diplomat in Training
I agree with the IR/HPS heat reducing trichome production. Definitely looking forward to lighting without the intense IR.
The "UV produces more trichomes" theory I do not buy into. As Lost in a Sog pointed out, it's likely more to do with what goes on inside the trichomes. In my experience, trichome density has muuuuch more to do with environmental factors other than UV.
As for stickiness permanently trapping pollen, keeping it from ever pollinating anything. I never understood how this would be a function a plant would want. Interesting I've heard about this from nearly the first moment I began researching cultivation. And nearly 20 years later, it's still being quoted.
I can see trichomes acting as a heat sink. lol What are the thermal conduction abilities of cannabinoids and terpenes? lol Love it.
The "UV produces more trichomes" theory I do not buy into. As Lost in a Sog pointed out, it's likely more to do with what goes on inside the trichomes. In my experience, trichome density has muuuuch more to do with environmental factors other than UV.
As for stickiness permanently trapping pollen, keeping it from ever pollinating anything. I never understood how this would be a function a plant would want. Interesting I've heard about this from nearly the first moment I began researching cultivation. And nearly 20 years later, it's still being quoted.
I can see trichomes acting as a heat sink. lol What are the thermal conduction abilities of cannabinoids and terpenes? lol Love it.
It didn't answer my question. Any science backing that? Just a single scientific paper will do. "IMOs" don't.
Cheers
If you are not familiar with,google uvr8 protein and cannabis.
Well, that's interesting. But after reading some texts, I've also found contradictory results.
This text https://www.researchgate.net/public...ret_Beauty_of_Ultraviolet_Radiation_in_Plants is the easiest one. If you read it, it says this:
So, again contradictory results.
Also, even if UVB activates some genes, these aren't that important to plant maturation. Plants grown without any UVB mature and reproduce perfectly well.
Do we have something better?
This text https://www.researchgate.net/public...ret_Beauty_of_Ultraviolet_Radiation_in_Plants is the easiest one. If you read it, it says this:
So, again contradictory results.
Also, even if UVB activates some genes, these aren't that important to plant maturation. Plants grown without any UVB mature and reproduce perfectly well.
Do we have something better?
Well, that's interesting. But after reading some texts, I've also found contradictory results.
This text https://www.researchgate.net/public...ret_Beauty_of_Ultraviolet_Radiation_in_Plants is the easiest one. If you read it, it says this:
[URL=https://www.icmag.com/ic/picture.php?albumid=75868&pictureid=1949316&thumb=1]View Image[/URL]
So, again contradictory results.
Also, even if UVB activates some genes, these aren't that important to plant maturation. Plants grown without any UVB mature and reproduce perfectly well.
Do we have something better?
The important key in the above is using TOO MUCH uvb has negative impact. I dont doubt that.
You absolutely can grow amazing plants without uvb. For example , a proven cutting a grower can 25%thca without uvb, but with uvb the thca % can end up at 28-30%.
For legal markets obsessed with numbers that is a significant gain.
Having said all that im sure there are varietals that wont tolerate uvb as much as others.
Im not interested in convincing others to try it. I know it brings out some magic in some strains, and for a small tent hobbyist like myself the cost is insignificant.
I would say, spend a hundred bucks on some uvb and test on a couple known plants.
The text exposed before doesn't talk only about excessive UVB. It talks about UVB. There are more texts setting approximately the same.
I believe these hundreds of bucks don't provide such a significant gain. I can grow some plants outdoors, that I find to be better than indoors, but probably the UVB is not the only reason for that.
Lost in a SOG
GrassSnakeGenetics
i dont come here to make horses drink fyi..
Nothing exists in isolation in nature.
Last thing ill say, besides again that UVs definitely activate epigenetics in plants like all the rest of the spectrum which is common sense and widely proven, is that UVs kill fungi and bacteria on flowers and pass right through leaves, especially the B and far B, killing intracellular viruses which is pretty useful in a plant where its end product quality is so easily detectable. This isn't my opinion either, but no I'm not putting all the search terms in and wasting my time searching for you, i work 7 days a week.
I dont think UV light particularly increases trichome size or density and they can definitely harm trichomes.
Nothing exists in isolation in nature.
Last thing ill say, besides again that UVs definitely activate epigenetics in plants like all the rest of the spectrum which is common sense and widely proven, is that UVs kill fungi and bacteria on flowers and pass right through leaves, especially the B and far B, killing intracellular viruses which is pretty useful in a plant where its end product quality is so easily detectable. This isn't my opinion either, but no I'm not putting all the search terms in and wasting my time searching for you, i work 7 days a week.
I dont think UV light particularly increases trichome size or density and they can definitely harm trichomes.
i dont come here to make horses drink fyi..
Nothing exists in isolation in nature.
Last thing ill say, besides again that UVs definitely activate epigenetics in plants like all the rest of the spectrum which is common sense and widely proven, is that UVs kill fungi and bacteria on flowers and pass right through leaves, especially the B and far B, killing intracellular viruses which is pretty useful in a plant where its end product quality is so easily detectable. This isn't my opinion either, but no I'm not putting all the search terms in and wasting my time searching for you, i work 7 days a week.
I dont think UV light particularly increases trichome size or density and they can definitely harm trichomes.
Yes, there is much written about the effect of UVs on viruses, bacteria and funghi. I love the solar light and I would use it for growing indoors, if I could. But I don't think it is the purpose of this discussion. Neither anything related with horses, that's the first time I even see that expression written.
I believe if the UVs were that clearly involved in the growing of better weed, all of us would be growing with them. I would be the first interested, but nowadays I think that I get more weed and better weed increasing the power in the visible spectrum of the light.
Have a nice day.
Lost in a SOG
GrassSnakeGenetics
Doesnt have to be a uv light to put out uvs though.
CMHs are more and more popular because they hit uvs, check the spec. And ive noticed higher terps in cmh grown over hps.
Most blue light will hit the uva a bit.. i was just reading a study last night on royal blue leds containing enough uv still to kill staphalococcus aureus.
Theres a nice 600w 10k finishing bulb out now as well to lock terps in.
You dont need em to grow pot but since people are searching for more terps its heading this way for a reason, imo
CMHs are more and more popular because they hit uvs, check the spec. And ive noticed higher terps in cmh grown over hps.
Most blue light will hit the uva a bit.. i was just reading a study last night on royal blue leds containing enough uv still to kill staphalococcus aureus.
Theres a nice 600w 10k finishing bulb out now as well to lock terps in.
You dont need em to grow pot but since people are searching for more terps its heading this way for a reason, imo
Lost in a SOG
GrassSnakeGenetics
In terms of human perception as a pose to what is actually going on It might simply be that the damage caused is more offset in some grow environments by the improvement in end quality because of the reduction in pathogens.
Perhaps a hepa filtered enviro would show the same or greater improvement if this is the case.
There are just so many variables in a grow room and most if not all effect and inform the plant. Most people want to remain ignorant of what the light they are using is doing because its a meaty subject and for decades we just bought MH or HPS or mixed bulbs..
Perhaps a hepa filtered enviro would show the same or greater improvement if this is the case.
There are just so many variables in a grow room and most if not all effect and inform the plant. Most people want to remain ignorant of what the light they are using is doing because its a meaty subject and for decades we just bought MH or HPS or mixed bulbs..
.
Last edited:
brown_thumb
Active member
Grown outside in sunlight. Started Feb 1st and harvested May 25th. Longitude ~30 deg., latitude ~100 deg., altitude ~400 ft. There shouldn't be much UVB in the sunlight here. Current daytime temperature is averaging 90F at the moment but was certainly cooler when these were started.
