UV and seedlings?

SchmoeJoe

SchmoeJoe

Well-Known Member
I can't find any direct references to starting seeds under bulbs with supplemental uv. I'm wondering if anyone here has any direct experience?

I figure in nature they would be exposed to uv from day 1 but I spent a lot of money on these seeds, the Galactic Animal anyway (220 for a 7 pack!), so I want to see if anyone has any first hand exoerince too share. Normally I'd just start under t5's but mine are 220v only which isn't going to be available until some utility work gets done.
 
ANC

ANC

Well-Known Member
I don't know hey, if you know what you are doing with 23W spiral CFLs you can grow a mean plant in 10 days from seed.
 
SchmoeJoe

SchmoeJoe

Well-Known Member
full of purple said:
Hps allways grows faster than cfl for me
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T5s are HO (high output) fluorescents. CFLs are compact fluorescent lights. Not the same thing. I've vegged under 4' 8 tube t5s for a long time with no issues with slow growth. Metal halides will give faster growth but I'm always pushing the limits in my veg space as it is. Even the new more balanced spectrum hps bulbs will create longer internodes which means the plants take up more space and have fewer but sites.
 
SchmoeJoe

SchmoeJoe

Well-Known Member
Dr. Who said:
The problem would be in delivering more UV then the sun.
Leave the UVB supplementing for bloom.
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I'll update this with the particulars of the setup when I get it rolling. As far as leaving the UV for flowering the main thing that really got me curious about this was a side by side from hortilux. In the page with their new PowerVeg t5s was a video that showed the difference in amount and quality of growth of seedlings with UV compared to without. It was significant and they provided all the information necessary to recreate the experiment all the way down to brand and strain of seed used. I believe they were tomatoes. Seemed very credible.
 
Kingrow1

Kingrow1

Well-Known Member
SchmoeJoe said:
I'll update this with the particulars of the setup when I get it rolling. As far as leaving the UV for flowering the main thing that really got me curious about this was a side by side from hortilux. In the page with their new PowerVeg t5s was a video that showed the difference in amount and quality of growth of seedlings with UV compared to without. It was significant and they provided all the information necessary to recreate the experiment all the way down to brand and strain of seed used. I believe they were tomatoes. Seemed very credible.
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Yes because tomatos probably have the UVR8 photoreceptor as well as the blue red nominal cry1/cry2 and phyt1/phyt2 photoreceptors.

As for hemp/marijuana i dont think so but most plants can be subdivided into uv sensing and non uv sensing.

Arent thvc strains more prone to chemical changes from uv light idk i forget a lot.

Either way no one has ever proved anything on these boards, id give up now unless you have some new angle or somthing :-)
 
SchmoeJoe

SchmoeJoe

Well-Known Member
Kingrow1 said:
Yes because tomatos probably have the UVR8 photoreceptor as well as the blue red nominal cry1/cry2 and phyt1/phyt2 photoreceptors.

As for hemp/marijuana i dont think so but most plants can be subdivided into uv sensing and non uv sensing.

Arent thvc strains more prone to chemical changes from uv light idk i forget a lot.

Either way no one has ever proved anything on these boards, id give up now unless you have some new angle or somthing :-)
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I'm not trying to prove anything to anyone but myself. As for as the finer points of the specific biological mechanisms I'm pretty ignorant but I do know that drug type cannabis strains do respond to UV. Maybe I'll have to take the extra step and run a proper side by side for comparison. My main concern was just whether using the bulb with UV was safe for seedlings and using the ones that I have hundreds or thousands of would've been enough of a test.

UV exposure causes the plant to convert cbg into cbd and thc so the plant is definitely in the UV responsive set. Whether that will have any direct affect on seedling growth for the better I can't say. There was at least one accredited university study that showed an increase in the canniboids in the thc strain used in the study but no change in the hemp strain so you're right about that as far as the best information I know of on that.
 
Kingrow1

Kingrow1

Well-Known Member
SchmoeJoe said:
I'm not trying to prove anything to anyone but myself. As for as the finer points of the specific biological mechanisms I'm pretty ignorant but I do know that drug type cannabis strains do respond to UV. Maybe I'll have to take the extra step and run a proper side by side for comparison. My main concern was just whether using the bulb with UV was safe for seedlings and using the ones that I have hundreds or thousands of would've been enough of a test.

UV exposure causes the plant to convert cbg into cbd and thc so the plant is definitely in the UV responsive set. Whether that will have any direct affect on seedling growth for the better I can't say. There was at least one accredited university study that showed an increase in the canniboids in the thc strain used in the study but no change in the hemp strain so you're right about that as far as the best information I know of on that.
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Uv light is useless for photosynthesis which is why i mentioned plant receptors as they can facilitate change based on certain light frequency.

Indoors adding uv to grow lights is a vast difference from the suns spectral range and intensity, cmh lights initially provided too much but i believe the next gen ones are more restrained.

I can only guess, indoor plants grow just the same as outdoor, more worthwhile experiments were done in sunlight with uv filters rather than indoors with added uv lights.
 
SchmoeJoe

SchmoeJoe

Well-Known Member
Kingrow1 said:
Uv light is useless for photosynthesis which is why i mentioned plant receptors as they can facilitate change based on certain light frequency.

Indoors adding uv to grow lights is a vast difference from the suns spectral range and intensity, cmh lights initially provided too much but i believe the next gen ones are more restrained.

I can only guess, indoor plants grow just the same as outdoor, more worthwhile experiments were done in sunlight with uv filters rather than indoors with added uv lights.
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PAR is not an accurate measure of lighting efficiency. It's already been shown that UV and IR affect growth even though they don't directly effect chlorophyl production.
 
Dr. Who

Dr. Who

Well-Known Member
SchmoeJoe said:
I'll update this with the particulars of the setup when I get it rolling. As far as leaving the UV for flowering the main thing that really got me curious about this was a side by side from hortilux. In the page with their new PowerVeg t5s was a video that showed the difference in amount and quality of growth of seedlings with UV compared to without. It was significant and they provided all the information necessary to recreate the experiment all the way down to brand and strain of seed used. I believe they were tomatoes. Seemed very credible.
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That is very interesting Joe! To be sure!

Thanks for posting that thought!

I gotta say, there would be a point when too much is just that. Pushing past the sun's delivered amounts. Has fried plants when testing UV some years ago..... lowering exposure time, with higher output sources. Did fix the problem. So it's got a saturation point, so to speak.
 
SchmoeJoe

SchmoeJoe

Well-Known Member
Dr. Who said:
That is very interesting Joe! To be sure!

Thanks for posting that thought!

I gotta say, there would be a point when too much is just that. Pushing past the sun's delivered amounts. Has fried plants when testing UV some years ago..... lowering exposure time, with higher output sources. Did fix the problem. So it's got a saturation point, so to speak.
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For sure. I'd imagine it's pretty much the same as skin exposure except for how the plants continue to produce new tissue. From what I understand the cbg levels are highest in flowering at about the 3/4 mark. Increasing the UV at that point makes sense for increasing potency without hurting yields since most strains have done most of the bulk of their growing and it's right about the peak of the cannabinoid precursor.

For now I'm hoping to find out if early UV exposure has the same affect on early veg development as it did in the hortilux demonstration. I'll do the side by side with my bulk seeds first though.
 
Kingrow1

Kingrow1

Well-Known Member
SchmoeJoe said:
PAR is not an accurate measure of lighting efficiency. It's already been shown that UV and IR affect growth even though they don't directly effect chlorophyl production.
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So someone takes a well known Uv sensing plant that is well documented to carry the Uvr8 receptor and a certain portion of cry1 blue light reception in the uv wavelengths that weve all known about for years through greenhouse studies and all of a sudden it applies to weed.....

None of what is seen in a tom plant is reported to be seen in weed or hemp as far as i know. Some plants sense it some dont.

Ir again depends more on the plants sense of red, some plants reverse the reaction and reset with red not ir. This again is dependant on temperature as the higher the temperature the less the ir/red photoreceptors work.

Some species grow deformed with no blue light, certainly weed senses blue and red but at high enough intensity the difference is blurred.

Par is a great interpretation of light but it dosent end there and thats where light is misunderstood, its why you can grow plants with enough green light but you will short the photoreceptors and the plant will be partly confused.

I can but ramble, why would your results be different to the many before you and if somthing many times.previously tested worked so well wouldnt we all be doing it.
 
SchmoeJoe

SchmoeJoe

Well-Known Member
Kingrow1 said:
So someone takes a well known Uv sensing plant that is well documented to carry the Uvr8 receptor and a certain portion of cry1 blue light reception in the uv wavelengths that weve all known about for years through greenhouse studies and all of a sudden it applies to weed.....

None of what is seen in a tom plant is reported to be seen in weed or hemp as far as i know. Some plants sense it some dont.

Ir again depends more on the plants sense of red, some plants reverse the reaction and reset with red not ir. This again is dependant on temperature as the higher the temperature the less the ir/red photoreceptors work.

Some species grow deformed with no blue light, certainly weed senses blue and red but at high enough intensity the difference is blurred.

Par is a great interpretation of light but it dosent end there and thats where light is misunderstood, its why you can grow plants with enough green light but you will short the photoreceptors and the plant will be partly confused.

I can but ramble, why would your results be different to the many before you and if somthing many times.previously tested worked so well wouldnt we all be doing it.
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My first post was asking anyone with first hand experience to chime in. As far as "none of it being known to apply to weed as far as you know" you should look up the university study that I mentioned in reply to one of your comments.
 
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Kingrow1

Kingrow1

Well-Known Member
SchmoeJoe said:
Lik


My first post was asking anyone with first hand experience to chime in. As far as "none of it being known to apply to weed as far as you know" you should look up the university study that I mentioned in reply to one of your comments.
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Ya read it before many times, watched peeps try the same stuff, didnt do a thing. Cmh on the other hand, thats got a shot at reversing tjis trend.
 
SchmoeJoe

SchmoeJoe

Well-Known Member
Kingrow1 said:
Ya read it before many times, watched peeps try the same stuff, didnt do a thing. Cmh on the other hand, thats got a shot at reversing tjis trend.
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Why would it be any different? Seriously though, you seem to know something about this already so I'm curious what you might know that would set them aside.
 
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