Don’t worry I go overkill with the sulfur, I’m a maniac! The first time I did it I diluted some 33% so it wasn’t very strong but it still worked.
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I have found the online generalizations about fighting PM to be quite accurate and have cured multiple plants of PM using many of the different posted methods… baking soda sprays taste bad, sulfur works but is a nuclear option that is incompatible with oils and cannot be used in flower, peroxide works fine, but oil always worked the best for any stage of growth or flowering: sulfur can NOT be used during flowering. At CCG we used AQ10, ampelomyces Quisqualis which is a hyperparasite of PM in our IPM regiment and never had an PM outbreak. The thing is, when fighting PM, you may also need to consider cleaning your floors, walls, fans, air ducts leading into the grow space… Then whichever of the methods I have suggested be used needs to be applied WITH FULL COVERAGE three times at three day intervals… today (Sunday), then again on Wednesday, and finally next Saturday. Sure Sulfur has a longer persistence and needs less applications but it can’t be used in flowering where most people need a solution for this issue… Of course your plants should be clean and disease free before going into flower, but sometimes things happen… you smoke some infected buds, latent spores hanging out on surfaces, external reservoirs…I have seen people only spraying the tops of their leaves later complaining of the solution not working. The solutions work, one just needs to know how to use them by applying them thoroughly and correctly. After you have cleaned your space one should also consider external reservoirs… your neighbors may be growing an infested crop so you should filter all incoming air and practice basic cleanliness techniques…washing hands, changing clothes, stepping on a greenhouse sterilization mat before entering your grow space. A little common sense and due diligence can go a long way.
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hmmm, sorry that information is not correct. If I just spray the plants alone with sulfur and not clean the ducting, the mildew is still wiped out. Repeat, I only have to walk into my grow room and spray all plants dripping with sulfur twice and it’s wiped out. I don’t have to do anything else.
In addition, even cleaning the empty room with bleach and no plants the mildew will regenerate from that. Doing the sulfur protocol is guaranteed eradication.
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Yeah, I came about that info first time thru with PM, I try and keep flower room at 40 which is tough when its 15 -20 rel. humidity outside. When it gets below 30% in the room Then add a too large temp change at lights off…boom PM. Yeah best prevention like pretty much any issue is get my environmental parameters corrected in addition to pest mitigation procedures
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Environmental conditions can trigger conidia formation. They won’t really slow or stop the parasite.
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Maybe, but making an environment not in the parasites comfort zone, does inhibit their ability to thrive, as with any living critter. Stacking the odds in our favour so to speak. Every little bit helps.
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Gotta give it a go 
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I just read something about using soaps as surfactants/stickers, and using a garden safe soap could be important. Apparently detergent type soaps can damage the sub-cutaneous layer on leaves by eating through the waxy membrane?
Yucca is another great surfactant.
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Believe it or not I’ve killed it multiple times with simple hydrogen peroxide but all three times it was OD, and was minimal as I caught it quick, used the peroxide/water mixture (can’t remember the ratio as I was told by a friend but it worked) haven’t needed it in many years but next time (if there is one) I’m trying your advice 100% thanks @JoeCrowe
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yah don’t use some kind of soap you have in the shower, or dish soap. They are not good.
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You sure that was powdery mildew? When I tried peroxide it did nothing, really.
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Yezzir 100% misted early am for a couple days, gonzo (pretty hard to mistake PM imo. I know people who are plagued by the shite)
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How long ago was that?
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7 years appx.
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ok thanks! I’ll do a trial with it along with @GPaw 's suggestion I try sulfuric acid as well.
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It was minimal though, very very far from systemic. Early stages 100% . I’ve seen it absolutely covering plants
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mmm that’s another thing right? They call it systemic, but what does that mean?
systemic:
(of an insecticide, fungicide, or similar substance) entering the plant via the roots or shoots and passing through the tissues.
Powdery mildew is actually a fungus located on the exterior of the plant, with a haustorium that penetrates the stomata and feasts on the plant cell goodies inside.
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Always wondered that myself, but I think possibly it was explained right to me once, “after it hits a certain point covering the majority it begins to invade the plant cells in their entirety, ie: systemic” this is just something I’ve been told by someone I very much look up to so who knows tbh definitely not facts as far as I know
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Peroxide does work against PM. Sadly it is highly reactive and volatile so it has a limited persistence… once the peroxide dries (10m to 4h) there is no continued protection against spores in the environment and those spores can be floating around longer than the peroxide remains effective… that particular use case definitely benefits from a full field day/cleaning of all associated equipment. Oil persists for a few days and sulfur longer so those strategies can be more effective with less re-applications. Please feel free to check out my username on IG if you need some sort of verification that I am not some random home grower attempting to understand basic science but instead have lived the profession and have industry standing from my years of experience running indoor greenhouses.
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Greenhouse growing definitely has its PM challenges ! My friend owns a very large cannabis business close by me and has greenhouse and full indoor automated setups. His regimen is insane and sometimes PM still pops up on certain strains, might be Niagara but I doubt it, as a friend in Cali has issues as well constantly outdoors
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