UVC and UVB light for mold control and increased trich production

xrob415x · Mar 25, 2012

I started this thread to open a discussion about using UVC light to control pests and mold and UVB light during flower to increase potency and trich production. I will be doin a UVB tests on a control group for their last 2 weeks. Has anyone done any experiments with this lighting. I read a study stating that thats a big reason MH lights increase resin production when used the last 2 weeks of flower. MH produce more UVB that HPS.

Dr. Detroit · Mar 25, 2012

They're more reliable for expressing coloration in the phenotype than for increasing potency very much. My last test went @ 14.9% under a ten percent UVB concentration overall, while the control plant tested @ 14.0%THC with no UVB supplementation. Not a very big difference at all, but the coloration of the two diverged massively.

UVC should never be given direct exposure to plants, but burying it in the ducting to kill airborne pathogens is effective.

xrob415x · Mar 26, 2012

Thanks for the feedback bro. about a 1% increase is decent. So that shows that potency was raised. How far from your canopy did you place the uv light? Also what weeks was it used? I wonder how far you could boost potency if 20% Uvb was used or the bulbs were closer to the canopy. Did you notice any significant increase in resin production? Since the resin is meant to block UV rays I would think that increased UV would also increase resin. Onto the UVC. I read on another forum about a guy who did a UVC test to control his powdery mildew. He used a 30w UVC bulb and place them 1,2 and 8 feet from the canopy. The plants with the light 1 and 2 feet away almost instantly started to die. The bulb 8 feet away didnt harm the plants and also controled the PM problem. Anyways the UVB light seems very promising to me. I am currently overseeing a Grape Ape grow and if the UVB gets some extra color to come out that alone would make it worth it to me!!!

StonerB · May 19, 2012

Real labs use UVC wands to sterilize worktops and I forget where I saw it but some commercial grows are even putting plants onto a conveyor belt type system that gets a UV blast for a few seconds per day to control pathogens. Yes MH produces way more UV than HPS but either one is more effective with NO GLASS on your hood. The glass filters a lot of the UV. In my opinion the reason for the resin increase is our plants use the resin as a shield, if there is more light to shield more resin is needed to do this. I dont think a simple THC test will accuratly measure this effect because who says THC is the sun-block. Maybe you increased CBD or CBN . More lab work is deff needed in this area. Please post any results, I am interested .

El Cerebro · May 19, 2012

which uv lamps are you guys using?

smartcalyx · May 19, 2012

El Cerebro said:
which uv lamps are you guys using?

Bump!

Thoth · May 19, 2012

How many plants did you use in your test Dr. Detroit?

xrob415x · May 26, 2012

The lamps i seen used were reptile lights and tanning bed lights. I have read from many scources that the glass on the reflectors does block a large ammount of the UV light just as stoner b stated. Im trying to figure out how many watts and how long of light duration should be used to get best results. Do a google search of trichlomes THC and UVB light. I would like people to shard how many watt lamp was used, the duration and distance from the canopy.

Toker Ace · May 30, 2012

400w, 10,000k mh, I've tried using it a few different ways. I have a 4'x6' room with a 600w hps on a mover. When I got the light I had one plant 1 week away from harvest. I pulled the plant to one end of the room and hung the 400 over it. The 600 w light would just bump into it. So, that plant had mh 10,000k constant and hps when the light traveled to that end of the room. I went bare bulb, to use all of the uvb. The plant gets frosty-er within a few days this way. I don't think the weed is any stronger but the only way I have to test it is not really quantitatively accurate. The "bag appeal" I would say was greatly enhanced. That I compared to a previous several harvest's nugs. The next run, using the same cultivar I figured more is better. I put the light in +/- 3 weeks till the end. This I would not recommend. The sugar leaves coming out of the flowers grew freakishly big, the buds didn't firm up, it was still covered with frost. Possibly a technique for extraction crop but not for me. The last plant I harvested had just the mh to finish.(no hps at all) and this works pretty good as well. The weed isn't as frosty looking but when I put it in the tester frequent "brown outs" occurred. I will continue to adjust how I use it and try to figure out what to do and what not to do.

Dr.X · May 30, 2012

According Marihuana Man (cannabis culture/pot TV) The bag appeal increased a lot. And he also believe increase thc production.
According Ed Rosenthal, Thc increase proportionally with the amount of UVB used in the grow, and also increase terpenes production. (he recommend to use 10% of your total wattage for UVB)
I tried myself and didn't see any noticeable difference between the one I didn't use UVB and the one with UVB, but here we don't have labs to test it. I would like to see some one experimenting with it and show real results.

Galderan · Dec 17, 2021

Check out this site. They were able to get a 33 percent increase in THC.

UVB: A Critical Frequency Range for Cannabis

As research ramps up on how lighting affects cannabis, many are focusing on how UVB affect

www.maximumyield.com

Galderan · Dec 17, 2021

Check out this video at 5 and a half minutes.

Observationist · Dec 17, 2021

xrob415x said:
Thanks for the feedback bro. about a 1% increase is decent. So that shows that potency was raised. How far from your canopy did you place the uv light? Also what weeks was it used? I wonder how far you could boost potency if 20% Uvb was used or the bulbs were closer to the canopy. Did you notice any significant increase in resin production? Since the resin is meant to block UV rays I would think that increased UV would also increase resin. Onto the UVC. I read on another forum about a guy who did a UVC test to control his powdery mildew. He used a 30w UVC bulb and place them 1,2 and 8 feet from the canopy. The plants with the light 1 and 2 feet away almost instantly started to die. The bulb 8 feet away didnt harm the plants and also controled the PM problem. Anyways the UVB light seems very promising to me. I am currently overseeing a Grape Ape grow and if the UVB gets some extra color to come out that alone would make it worth it to me!!!

Y’all need to use UVA AND UVB

phyllosphere · Jan 27, 2022

The most recent evidence suggests that UV exposure does not benefit cannabinoid synthesis. I will try to find the relevant link. There is lots of evidence of UVC efficacy for eradication of pathogens in HVAC applications. I have used UVC to eradicate PM in commercial grows with great success. Here is a link to kind of a long IPM article with some good info about UVC crop treatments. https://www.elevatedbotanist.com/cultivation/ipm

phyllosphere · Jan 27, 2022

phyllosphere said:
The most recent evidence suggests that UV exposure does not benefit cannabinoid synthesis. I will try to find the relevant link. There is lots of evidence of UVC efficacy for eradication of pathogens in HVAC applications. I have used UVC to eradicate PM in commercial grows with great success. Here is a link to kind of a long IPM article with some good info about UVC crop treatments. https://www.elevatedbotanist.com/cultivation/ipm

Here is a link to recent trial data https://www.frontiersin.org/articles/10.3389/fpls.2021.725078/full

UVC and UVB light for mold control and increased trich production

UVC and UVB light for mold control and increased trich production

xrob415x

Dr. Detroit

xrob415x

StonerB

El Cerebro

smartcalyx

Thoth

xrob415x

Toker Ace

Dr.X

Galderan

UVB: A Critical Frequency Range for Cannabis As research ramps up on how lighting affects cannabis, many are focusing on how UVB affect www.maximumyield.com

UVB: A Critical Frequency Range for Cannabis

Galderan

Observationist

phyllosphere

phyllosphere

Privacy & Transparency

Privacy & Transparency

UVB: A Critical Frequency Range for Cannabis

As research ramps up on how lighting affects cannabis, many are focusing on how UVB affect

www.maximumyield.com