Calling all PM experts. How do you deal?

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Aqua Man

Aqua Man

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I skipped all but the first page.... the most important part is prevention. Outdoor you may need to use products.

Indoors (MY opinion only)

It's most certainly an environmental issue.

VPD reduces stress and low humidity can be as bad as high humidity but as @Kanzeon I think was started the fluctuations are idea for infection and spread. Low humidity days and high night are a heaven for PM.

Let me make this absolutely clear so sorry for the caps.

PM DOES OT NEED FREE WATER TO GERMINATE AND LOW HUMIDITY IS A SPORE SPREADING FACTORY.

ok now that's put of the way temp also plays a role. Teml and humidity that fluctuate for hot dry lights on to cool humidity lights out are the FIRST thing to correct.

The SECOND is actually 2.... proper airflow and pruning to reduce microclimates. I CANNOT STREESS THIS ENOUGH. Leaves stacking on eachother and poor airflow THROUGH the plants is a huge issue for both transpiration and plant health but majorly for almost any bacterial or fungal infections. Toss a hygrometer in the middle of the canopy and look for yourself how much higher the humidity is. Much like room temps are used by many growers when it's the leaf temps that truly matter, humidity matters at the leaf within a few millimeters and it doesn't matter if your room is at the proper humidity when around the leaves are high.

There is a point at lights out where the temperature drops fast because no heat is being produced by the lights. Most growers don't realize how big this impact is in terms of humidity. And it can be so much that your exhaust fans and dehumidifier cannot catch up for several hours. If this is the case fix it.

Ok I'll stop my ranting now
Holy English!!!! I'm just not going to edit it so you folks can have a laugh at my poor keyboard skills on this tiy phone with fat fingers and an autocorrect that speaks Pig Latin and has not completed the hooked on phonics program.... sheesh.
 
elduderito

elduderito

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I found PM in my veg tent last week, seems to only be on a few freshly rooted cuts - I sprayed immediately with neem oil as it's what I had on hand...

my friend told me he's used an organic fennel oil product which I went out and bought, an sprayed a few days later ... It seems to be working but I reckon I'll need to keep a close eye going forward...
 
TheWalkingPlant

TheWalkingPlant

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I’m another vote for starting by solving the night time rh spoke. But as a bandaid, Something I learned from the commercial world is that you can use h202 to solve a lot of issues (like pm), but you will lose terps. Buti guess that’s better than losing the whole plant. Biosafe has a cool product that’s h202 and vinegar that can be used up until harvest. Again, you sacrifice terps. Gas seems to stick around, but fruity shit is gone for sure. Still gets you high tho
 
Ponky

Ponky

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And in closing. Once it has even one spot of PM its now a pack with PM. Once you see it. You taste it.
 
radmobile

radmobile

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Update:
So I found this blueprint for a room my size:
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Instead of “small floor fan” in each corner I put box fans. Where the 9’ oscillating fan is, I have 2. There’s literally 9 fans running in a 8x13 room, not including the intake and exhaust fans. Please tell me this will rid my of pm! 🤞🏻
 
Dirtbag

Dirtbag

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Has nobody mentioned using a sulphur burner?
In British Columbia where I am there is PM everywhere, I've seen it crop up in some of the most highly tuned, optimized environments with meticulously pruned plants.
The vast majority of growers here use sulphur burners once a week up till about week 2 of flower for prevention. Even the Big vegetable greenhouses and commercial cannabis facilities around here use them to control PM. And as a bonus, it also controls mites.
 
Dirtbag

Dirtbag

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Update:
So I found this blueprint for a room my size:
View attachment 1174017Instead of “small floor fan” in each corner I put box fans. Where the 9’ oscillating fan is, I have 2. There’s literally 9 fans running in a 8x13 room, not including the intake and exhaust fans. Please tell me this will rid my of pm! 🤞🏻
That will not rid you of PM. It will help, but if there is PM in the room no amount of good VPD and airflow will eradicate it. Short of nuclear options, the best thing you can do is fumigate the room and contents heavily with sulphur.
I've fought and won the war against PM using sulphur to save genetics, but it took me a about 6 months and 3 generations of cloning to get PM free plants and a clean room again.
 
PizzaBob

PizzaBob

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That will not rid you of PM. It will help, but if there is PM in the room no amount of good VPD and airflow will eradicate it. Short of nuclear options, the best thing you can do is fumigate the room and contents heavily with sulphur.
I've fought and won the war against PM using sulphur to save genetics, but it took me a about 6 months and 3 generations of cloning to get PM free plants and a clean room again.
To save genetics just use Eagle20 and then take clones and maybe clones of that clone before I flower. After 180 days it’ll pass most tests.
 
radmobile

radmobile

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That will not rid you of PM. It will help, but if there is PM in the room no amount of good VPD and airflow will eradicate it. Short of nuclear options, the best thing you can do is fumigate the room and contents heavily with sulphur.
I've fought and won the war against PM using sulphur to save genetics, but it took me a about 6 months and 3 generations of cloning to get PM free plants and a clean room again.
Can you give me an example product to use? I worry about doing that in my house. This is a basement room in a house with kids and animals. Thanks for the info!
 
Ponky

Ponky

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If your air intake is at lawn level and sucking in from outside its sucking in a lot of spores. Make sure the intake is from inside the house. And filtered. The only Sulphur product I can really get where I am is Safers 3 in 1. And forget the label. Plants can tolerate it daily if they need it. The premix is the one you want. The concentrate leaves residue. It's organic and fairly mild.
 
Mrb53

Mrb53

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Can you give me an example product to use? I worry about doing that in my house. This is a basement room in a house with kids and animals. Thanks for the info!
I am not a fan of any of these harsh methods of dealing with WPM....
If you are willing to spend just a few dollars, I would try @Frankster for his

Dr. Frankenstein’s – bio-animation spray Bio-stimulant Fungicide​

I use it, many of my friends use it and it does / has and continues to help us with mold and other issues
I have turned on friends in Spain, Hawaii, East Coast, Heartland and every single one RAVES the results
I use it daily as a preventative and it is 100 Organic non-GMO and safe
My daughter is a Bio Med Engineer and she works for the water company. She says they use similar methods to address mold issues

here is the link but be advised, the web site is not complete, not ready for prime time and a work in progress
https://castle-frankenstein.com/its...io-stimulant-fungicide-insecticide-surfactant
 
radmobile

radmobile

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If your air intake is at lawn level and sucking in from outside its sucking in a lot of spores. Make sure the intake is from inside the house. And filtered. The only Sulphur product I can really get where I am is Safers 3 in 1. And forget the label. Plants can tolerate it daily if they need it. The premix is the one you want. The concentrate leaves residue. It's organic and fairly mild.
Likely my issue, sir. My intake is about 2 feet off grade level and it’s up underneath a sill. I’ll see if I can try to get air from the house instead. Thanks!
 
Ponky

Ponky

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Ok good. I would also get some furnace filters and build a box for them. So your air intake filtered as much as possible. Hope this sorts it out.
 
radmobile

radmobile

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Ok good. I would also get some furnace filters and build a box for them. So your air intake filtered as much as possible. Hope this sorts it out.
I figure I can just use the same carbon filter as with the exterior intake? Or should I use a box instead? The crappy part about the carbon filter is that it would require me to push air out of the filter itself, into the room. If I set it up like HVAC, I would probably get better air movement and the filter replacement would probably be cheaper….. hmmm 🤔
 
Ponky

Ponky

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I figure I can just use the same carbon filter as with the exterior intake? Or should I use a box instead? The crappy part about the carbon filter is that it would require me to push air out of the filter itself, into the room. If I set it up like HVAC, I would probably get better air movement and the filter replacement would probably be cheaper….. hmmm 🤔
No I would use just furnace filters. You can use a cardboard box the make them work with a duct hose. They're cheap. Like 12 bucks a piece. Having a really good filtering efficiency. I bought a 12 pack of filters for like 80 bucks. Work great. You'd be shocked at how much it catches. Charcoal would be expensive.
 
radmobile

radmobile

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No I would use just furnace filters. You can use a cardboard box the make them work with a duct hose. They're cheap. Like 12 bucks a piece. Having a really good filtering efficiency. I bought a 12 pack of filters for like 80 bucks. Work great. You'd be shocked at how much it catches. Charcoal would be expensive.
Great advice, and another cool project for the grow room! I’m Always into improving things for the ladies 😎
 
Dirtbag

Dirtbag

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To save genetics just use Eagle20 and then take clones and maybe clones of that clone before I flower. After 180 days it’ll pass most tests.
I agree, that's exactly what I would have done if I didn't live in Canada where we can't even buy spinosad, let alone eagle or Nova.
Can you give me an example product to use? I worry about doing that in my house. This is a basement room in a house with kids and animals. Thanks for the info!
I wouldn't use a burner in a house unless the grow room is really well sealed and vents outdoors. Better off with a wettable powder sulphur that you can spray on. Many different brands. Just don't use it on flowers.
 
elduderito

elduderito

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I spotted powdery mildew for the first time about 2 weeks ago on one plant - I've sprayed down three times now (neem oil, fennel oil x2) ... So far I've only seeing symptoms (max 2 or 3 white fuzzy spots) on a few plants ... would it make sense to simply discard the 'infected' plants - or do I just assume all of my plants have been infected?

Fortunately it seems like it's only in the veg tent - but in the coming weeks I'm supposed to start moving some plants into the flower tent...
 
Ponky

Ponky

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I spotted powdery mildew for the first time about 2 weeks ago on one plant - I've sprayed down three times now (neem oil, fennel oil x2) ... So far I've only seeing symptoms (max 2 or 3 white fuzzy spots) on a few plants ... would it make sense to simply discard the 'infected' plants - or do I just assume all of my plants have been infected?

Fortunately it seems like it's only in the veg tent - but in the coming weeks I'm supposed to start moving some plants into the flower tent...
Always kill off the weak. Better that canopy space be taken by the strong. If its just one. Hell yeah. Toss it. Don't let it get the others sick. But aggressively treat them all. As if they're all sick.
 
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