UV-C kills powdery mildew

I saw in high times that uvc light kills pm...so I'm thinkin'- why haven't we got uvc lights suplementing indoor light. I'm not in the grow room long enough to get nuked, so I'm definitely gonna' run with this one! I googled it; and lo and behold- petco...flourescent tubes made of quartz...I imagine a couple of these, maybe on a light mover; or better yet- underneath the canopy!..I'm sure there'll be some ironing out of the parameters...but I'm gonna' do it. I just don't understand why it isn't a popular method. I'm certainly not the first one to put 2 & 2 together on this one!? maybe the light damages the plants? natural sunlight has it; which is why pm fails in good sunlight. uvc probably toughens up the leaves in proper doses. there's also these sanitizer light wands for about a hundred bucks that might be a real hit as well. they destroy the pathogens' ability to reproduce. a major use is hospital/hotel bed sanitizing.

Good question dude, I'm subscribed.

Id probably only really use it towards the end of flowering because I don't think PM would be a big problem until you get some dense nugs

Or is it way humid where your at or something?

I hear to long of exposure can also harm the plant.

that's what'll need to be ironed out: the parameters of length of time and intensity of exposure. I'm sure that low levels of exposure may resolve a few things as far as indoor goes...like weak leaves(they burn in real sunlight), and the soil biology/insect world are different; even though the only thing I do different indoors is no algae water...I'd come to the conclusion early on that the light spectrum isn't close enough to sunlight- sure enough...the indoor plants are prettier, but lacking that verve you get from outdoor ganja.

UV-C is an extremely dangerous wavelength. DNA absorbs UV-C directly which is why it is used for germicidal lamps. It is true that natural sunlight contains it but our atmosphere filters UV-C out. Instead we get UV-B and ground level which is also very dangerous but nothing compared to UV-C when it comes to DNA damage.

This red dotted line is the action spectrum for DNA damage from UV.
View attachment 1048401
At ground level it is manageable 290-300nm UV-B, but without the ozone layer we would be toast except life in the water. UV-C lamps emit a peak around 250nm and the DNA action spectrum peaks at 264nm. So if UV-C can kill PM it is probably not something you could put in there and leave on for any length of time without killing the foliage.

Dawg ~ If you believe that sunshine kills PM then i have a bridge to offer you in New York! Been suffering with this PM shit for many months. Started inside, closed my room, headed for the great outdoors where the shot just got worse and WORSE. So forget sunshine. Whar you may want to try is a product called, Meltitox, , ,which is highly toxic. This is used by pros out west. 1.25 ml per liter, mist from toes to tops with just a MISTING , , PM is INSIDE the plant not ON the plant. It's amazing how little everyone's informed. This produce it sold in just afew places, I get mine through Medicine Man at [email protected]. This stuff is supposed to be the holy grail for getting rid the PM.
Okay, I got it, used it dressed in Moon Gear, and had so so results. I'm growing 27 different strains this grow, some responded well, others so so, some not at all. My Chem Dawg D's are fucked after 5 months of laboring. The RKS, Agent Orange, Vortex, Kandy Kush have all suffered the worst. The Hindu Kush, Bubba Kush, Lemon Skunk(DNA) are doing better than before the misting. All the sulfur sprays did was delay it. If ever you do beat this shit, spray with Neem Oil, Clove Oil, and garlic oil combined every 5 days. This will prevent it from returning. The lose is in the 1000's , , , , ,

I'm 100% not into any of that-addatives like neem oil or whatever germicidal product...absolutely NOT!!!!- sorry- I'm not budging on the sukiyaki purity thing. ain't happenin'. at the right blend; I'm convinced that the closest we can get to natural sunlight indoors, the better. weed grown at high altitudes(less atmosphere) is stronger than sea level. my skin looks like it's 20 yrs. older than it is because of living in the high desert and on the colorado plateau too long. 'dja ever notice how resin glands grow bigger on the undersides of leaves outdoors, but grow big all over indoors?- or how weak indoor leaves are compared to outdoor? and- yes uv-c DOES kill p.m.!- load up your brain before you shoot of yer mouth!

s.c.mtn.hillbilly said:

I'm 100% not into any of that-addatives like neem oil or whatever germicidal product...absolutely NOT!!!!- sorry- I'm not budging on the sukiyaki purity thing. ain't happenin'. at the right blend; I'm convinced that the closest we can get to natural sunlight indoors, the better. weed grown at high altitudes(less atmosphere) is stronger than sea level. my skin looks like it's 20 yrs. older than it is because of living in the high desert and on the colorado plateau too long. 'dja ever notice how resin glands grow bigger on the undersides of leaves outdoors, but grow big all over indoors?- or how weak indoor leaves are compared to outdoor? and- yes uv-c DOES kill p.m.!- load up your brain before you shoot of yer mouth!

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I agree with you on the whatever chemicals "nine coats" is talking about that sounds like nothing I would want to smoke, but have you really given neem oil a chance?? pure neem is 100% organic extracted tree oil and if used properly works great!! have tried all the rest (organic methods) and nothing works 100% as once the fungus is in the plant/root zone it is nearly impossible to eradicate, but the neem will def keep a nice oily layer on the leaves so the spores of the fungus can't spread...I am very interested to see how your uv-c endeavor goes, maybe you will stumble upon something none of us have ever thought about! It just seems like a big risk of time and money and plant health if it does not work, but to each his own right??

I agree, the Meltitox is troubling at best and disheartening at worse. BUT , , , what about losing all the ladies? How's that for your head? The Meltitox was suggested to me by a organic certified grower named Medicine Man whose been in High Time 2 times for his growing abilities. Now anyone that doesn't understand Neem oil shouldn't be growing, right? I mean, how much more natural product can one use?
AND THE PLANTS LOVE IT. I would suggest reading more about products before giving them the evil eye.
Hey, if you think spraying diluted milk is your answer to PM , , well spray away !
Dready Bob just finished an article in Weed World where he visited 100 different grow ops out West. Every grow opt had some kind of PM going on. EVERY ONE. Clove oil, garlic oils are more aid in the fight against PM, along with Neem Oil. One thing for sure , , IT IS INSIDE THE PLANT, so forget wiping it off with Qtips LOL ! Sunshine will not help either. Here's what i did that did have some good results: I removed all the trouble areas, in essence loopypopping them. After removing the "bad shit" which looks like "scales" on the stems and branches, or trying to clean it up, Then moving them into the shade as the sun just burns them up faster as they have no defence against the heat and rays as the larger leaves are all gone. I sprayed with the Meltitox"LIGHTLY" and left them to do whatever they do. They got better in a week, then began to grow normally from the top. They are my prized Jack The Ripper.
If anyone discovers ANYTHING that deals with this shit, they gonna make some serious bucks as nothing yet kills it , , , , besides luck and regrowing from beans. I lost my Chemdawg D after 5 months of struggles. She was 6 feet tall and had close to 8 ozs on her , , , , all gone to shit day by day.
Hey mates, don't hate on the old Nines too bad , just trying to help out.

that sucks dude, never lost a harvest to the stuff, although it does take quite a bit of my time...I use neem oil 2-3 times a week and have not lost a crop yet. I just mix a few ml of 100% neem extract and a little bit of wet betty to help coat the leaves (always use warm water) I live a mile from the beach it is usually over 60% humidity and foggy as hell. Just takes a little neem and patience every day no "Meltitox" chemicals are necessary as herb grown with chemicals sprayed on them is no longer medicine of any sort. My main problems are those damn caterpillars

Been growing 42 years and never seen a caterpillar on herb. Is that a beach thing?
Hey, I'm so down with Neem, okay, but it doesn't cure the PM problem. I also adimt i'm not growing 6 plants, rather there's 27 different world class strains, several of each, banging back the sunlight as i write. Wanted to retract one of my statments which is the cool thing about this site, no one knows everything, and half of what we do know is somehow wrong. I was assured that PM was INSIDE the plant, not on the leaves by people that should understand the issue. After reading this last issue of HTimes(which i really dislike),and read that PM is in the top most epidermal layer, or the plant's skin. I've also heard that it is in the roots. For sure it starts out as white spots on the bottom leaves. I wouldn't mist my ladies now if you had a gun on me ! My plants took the PM on to the stems, starting at the bottom. It looks like white scales that cover the entire stem, then work their way upwards, the leaves dying as the PM travels upwards, the smaller inside leaves and branches are
all fucked, darkish looking, the leaves all turning yellow then falling off. What is amazing is, except for the prized Chemdawg D, they keep on growing ! Not well, but a tribute to the species. The DNA RKS, and all Subby's gear took a hard hit. Yet they all continue to grow. Also, UV light kills molds, for the most part, yet the ladies have no power to sit in the hot sun all day without crapping out. That is why my experience is that sun is not the cure either.
Okay, pile on , , ,LOL !

Saw this topic and had to respond! UV-C light indeed kills PM and other fungus that grows from the outside in! I use a special uvc lamp (different from hospitals etc) now myself against PM and the results are great! Regarding the safety issue: you can't look into the lamp (wear uv safety glasses at all times) and if you light your skinn for a couple of minutes you will get a little sunburn..
In the beginning you have to get the feeling for it, how long should you light it and from what distance.. They say that 2-5 seconds of light on one spot is enough, if you do it any longer you will damage the plant (gets a little brown but recovers in a day). How bigger the distance to the plant is the longer you can light it, I keep the distance between 5-10 centimeter..I really love this treatment because I don't use any other products to kill PM anymore! I can see that this lamp even improves the quality of the plant, this light leaves the layer around the leaves intact so it becomes stronger and more resistant against all kinds of fungus and the color of the plant becomes brighter because you give the plant a dosis of UV light each time. Perfect solution against PM, just wear the glasses and get the feeling for it!

Sr. Verde said:

Good question dude, I'm subscribed.

Id probably only really use it towards the end of flowering because I don't think PM would be a big problem until you get some dense nugs

Or is it way humid where your at or something?

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u must be thinking of bud rot.. pm can come on anytime, even during veg, it is a disease of the plant.. like herpes in humans.. bud rot comes when your buds are too dense at the end of flower due to moisture being retained in the inside of the buds.

i had pm at one time. u cure it by completely dipping your plants in dutchmaster zone and penetrator/saturator combo.. when u take clones this is the best time to do this.. then do a sulfer burning without the plants in there.

Hey guys, You dont want mold? get a dehumidifier. rh < 55% and you wont ever see it again. start with a clean room/clean plants.

and wtf?! -neem is amazing and harmless. your not supposed to spray anything in flower so why worry about smoking it? purity is the utmost importance to me and I use azamax as a preventative. I also use spinosad bacterium. the two together makes gardening much more zen.