Trichomes, THC and UVB light.....

DaveCoulier

Well-Known Member
Tahoe did you notice an increased speed at which your Thrichromes turned amber? I read a thread on another site regarding UVB, and a guy ended up with 50% amber after running the lights for 3 light periods straight in late flowering(last week I think) 8-10 hours a day.

He suggested running the lights heavy in early flowering and gradually taper off near the end to prevent this. Whats your thoughts?
 

damnbigbudz

Well-Known Member
[FONT=Arial, Verdana, sans-serif]1. REPRESENTATIVE LIGHT SOURCES AND THEIR PRINCIPAL TYPES OF RADIATION
Note: Wavelengths responsible for conversion of 7-dehydrocholesterol to cholecalciferol: 280-315nm
[/FONT] [FONT=Arial,Helvetica,Verdana]SOURCE[/FONT]
[FONT=Arial,Helvetica,Verdana]RADIATION[/FONT]
[FONT=Arial, Verdana, sans-serif]Sun[/FONT]
[FONT=Arial, Verdana, sans-serif]UVB 290-320 nm, UVA 320-400 NM, Visible 400-700 NM, Infrared >700 NM[/FONT]
[FONT=Arial, Verdana, sans-serif]Incandescents (frosted, reflector floods, spots, halogen lamps[/FONT]
[FONT=Arial, Verdana, sans-serif]UVA 320-400 NM (low levels), Visible 400-700 NM, Infrared >700 NM[/FONT]
[FONT=Arial, Verdana, sans-serif]Fluorescents:[/FONT]
[FONT=Arial, Verdana, sans-serif]Chroma 50, Colortone 50, Design50, Cool White, Warm White[/FONT]
[FONT=Arial, Verdana, sans-serif]Visible 400-700 NM
UVB 280-320 NM (low levels), UVA 320-400 NM (low levels)
[/FONT]
[FONT=Arial, Verdana, sans-serif]Plant lights[/FONT]
[FONT=Arial, Verdana, sans-serif]Emphasize red and blue spectrums within Visible 400-700 NM[/FONT]
[FONT=Arial, Verdana, sans-serif]Blacklights (BL)[/FONT]
[FONT=Arial, Verdana, sans-serif]UVB 290-320 NM (low levels similar to Vita-Lite), UVA 320-400 NM[/FONT]
[FONT=Arial, Verdana, sans-serif]Blacklight Blue (BLB)[/FONT]
[FONT=Arial, Verdana, sans-serif]Same as BL but with less blue light emitted; reported harmful to eyes[/FONT]
[FONT=Arial, Verdana, sans-serif]Sun lamps, Germicidal Lamps, Phototherapy lamps[/FONT]
[FONT=Arial, Verdana, sans-serif]High levels of UVB causes skin cancer, cataracts, etc.[/FONT]
[FONT=Arial, Verdana, sans-serif]Other UV Sources:[/FONT] [FONT=Arial, Verdana, sans-serif]High Intensity Discharge Mercury, Metal Halide[/FONT]
[FONT=Arial, Verdana, sans-serif]Visible 400-700 NM, Infrared >700 NM; UVA and UVB are shielded due to extensive damage to skin and eyes caused by such high intensity[/FONT]
[FONT=Arial, Verdana, sans-serif]Mercury vapor combo heat/UV product[/FONT]
[FONT=Arial, Verdana, sans-serif]Extremely high output of UVA and UVB posing health hazards to humans and reptiles in typical home setting

IT IS COMPLETELY POSSIBLE THOUGH THAT I AM READING THIS WRONG
[/FONT]
 

DaveCoulier

Well-Known Member
Oh, now I see what you're getting at. The reason people aren't using blacklights for UVB is because its output probably isn't as intense as Mercury Vapor Bulbs, etc. It also doesn't have any of the visible wavelengths the plants also need. I couldn't come up with any data showing how much UVB light blacklights provide over varying distances, but Id steer clear of them and just use a MVB.
 

420pharms

Member
tanning bed lamps? merc vapor ? I have a freind who works in a light testing lab I have been trying to get his cooperation and he says he will but that remains to be. I have so many things to get under control now that I may not be playing UVB yet, but I will
 

420pharms

Member
do you think that my trichs wont turn is due to lack of uvb co2 enriched 4x600w hps? can get them a little milky but thats it I have indicas that are close to 12 wks in bloom counting first wk sativas that should run 12wks pistols ready in 10wks ?
 

DaveCoulier

Well-Known Member
Its not a lack of UVB. People grow and harvest all the time indoors w/o UVB. Your plant is probably just a later bloomer :)
 

420pharms

Member
violator kush, pure power, afgan kush, blueberry all indicas all over 11wks no amber visable I am not really on topic but Im not getting normal results no fresh air co2 enriched temp contlroled
 

RanTyr

Active Member
Amazing thread with a great deal of information. Unfortunately we may never know the fulle ffects of UV light on living things in our lifetime. Having undergone a trial that involved UV treatment for SAD I can assure that under-doing it is better than over-doing it.
 

tahoe58

Well-Known Member
hey ya'll .... thanks for poppin on in. Yea overdoing it is nasty. I am very interested in the comment relating to the acceleration of trichome maturation. My last set of plants have had some challenges I thought mostly to pH/nutes screwups of my own. But I am going to think about that other aspect some more because it would follow that the uvb light intensity would be dynamic and somewhat seasonal with the exception of directly at the equator. Something to ponder ...while enjoying the fruits of the labour. :blsmoke::blsmoke::blsmoke::blsmoke::blsmoke: I dunno, in my view I looked into it because it was interesting, and I had the time. My effort was rewarded with a belief that it would be beneficial to add it to the process. With no quantitative support, I believe it does improve the product. And in a way, that all that matters ..... Walk on!!~~~~~
Amazing thread with a great deal of information. Unfortunately we may never know the fulle ffects of UV light on living things in our lifetime. Having undergone a trial that involved UV treatment for SAD I can assure that under-doing it is better than over-doing it.
 

Roland

Active Member
do you think that my trichs wont turn is due to lack of uvb co2 enriched 4x600w hps? can get them a little milky but thats it I have indicas that are close to 12 wks in bloom counting first wk sativas that should run 12wks pistols ready in 10wks ?

Try taking a few buds and drying and curing them .. mine seem to turn more amber after a couple weeks of curing

also: turn the lights off for a few cycles and cut nutrient's back .. that should help trich's turn amber ...

I'm also a believer in fresh air
 

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6wayswinger

Active Member
Ok then firstly on a cloudy day in uk uvb levels can be 200 thats through the clouds lol so putting a 7% or 12% uvb bulb cant do any dammage?. so i used a 7% reptile bulb from 12 12 switchover. 12 hours a day till the end. ihad no problems whatsoever i did get some good trich coverage an was v strong. hope this is a helpull post :-?
 

tahoe58

Well-Known Member
Review

The effect of ultraviolet radiation on the accumulation of medicinal compounds in plants

Wen Jing Zhanga, b and Lars Olof Björna, c, ,

aLund University, Department of Cell and Organism Biology, Sölvegatan 35, SE-22362 Lund, Sweden

bQingHai Normal University, Key Laboratory of Resources and Environment in Qinghai-Tibet Plateau, Ministry of Education, Qinghai 810008, China

cKey Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China


Received 8 January 2009; accepted 11 February 2009. Available online 23 February 2009.
Abstract

A review is given of how the production by plants of compounds useful as medicines or raw materials for manufacture of medicines is influenced by ultraviolet radiation, particularly by UV-B radiation (280–315 nm wavelength). The compounds considered in this review are flavonoids and other phenolics, alkaloids (especially indole terpenoid and purine alkaloids), essential oils and other terpenoids, cannabinoids, glucosinolates and isothiocyanates, and compounds having human hormone activity. A short account is also given of ultraviolet signalling in plants. The review concludes with a discussion of the possible evolutionary mechanisms that have led to the evolution of UV-B regulation of secondary metabolite accumulation.

Graphical abstract

 

blueybong

Well-Known Member
I just wanted to share that I'm at the beginning of week 3 flowering and started using the ReptiSun 10.0 UVB Desert @ week 1, with no ill affects. The bulbs on from 9am to 5pm, while the 400W HPS comes on @ 7am & off @ 7pm.

I'm growing 1 NL, 1 WW & 2 Thai in a 4'X4'X6.5' tent.


 

merahoon

Well-Known Member
I'm creeping up on week 2 of flowering and have not introduced uvb yet. I was curious as to when the best time would be to add the 10.0 uvb bulb. Also whats the best suggested time for it to be on?
 
I have done extensive testing and this is what I can offer.

If you are on a 12 -12 schedule, much like the fall season, think of sun intensity during the day. The strongest sun is usually during the fourth to seventh hour. That is when I turned my UVB"S on. Yes multiple, to the tune of 25 in a 130 sq ft. The pre and post hour I turned on for 5, off for 15, on for 10, off for 10, then on throught the seventh hour, and a degregation of the same on the 8th hour.

The test source were indentical clones, Test group A Inside, under 1000w hps, UVB, and a high color temp 26w CFL(mounted vertically in a four corner post layout), and Test group B outside just mother sun. The differnence was night and day. The addition of the UVB at a close high intensity created and explosion of tri's and enhanced smoke (when cured properly VERY IMPORTANT). Tri's act like sunscreen, and UVB will burn the crap out of anything if given the chance. You included! This can be very costly though, another method to achieve similar results when doing an inside grow, leave the MH on the first 10 days of the 12/12 intro. Switch to HPS until the last 14 days of your cycle and switch back to MH. Harvest only after letting your mama's sit in the dark for about 36-48 hours (see prior postings for exp. for doing this). Turn the lights on for an hour and harvest.

While on the subject of UV, I also utilize UVC lights to control insects and mold issues. This is a very tricky subject and should only be attempted by seasoned growers. It works extremely well, and I have even introduced pests, and molds in my growing enviroment to research the validity and ability to work... It does and is much better than the numerous products or homemade potions to control the same detriments.

Ok with all that said, PLEASE, turn off any UV light when entering a room. A,B,or C. It is very bad for you, especially the eyes!! Be safe, happy vegetating!
 
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