Ok, then pm does grow on stems, for certain. You can see it on the base of the stem in this pic. My next question, is the white powdery stuff on the hydroton, net pot, and roots a different organism? Is it bad, and how to treat it?
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PM is an obligate biotroph, which means it needs to feed off of a living host. In this case, living plant tissue. It’ll grow on leaves, petioles, and stems.
I’d guess that the stuff on the hydroton is not pm, unless it’s just a mass of spores that have happened to fall on the hydroton. There are so many things that will grow in the grow room, my environmental monitoring tests for 30 different fungi, yeast, and bacterium.
Send a swab out to your local lab, figure out what that is.
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I’m betting its calcium deposits.
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on my stems its milk stains. the pm in my garden is mild since I caught it early. ive seen it on a few leaves and spray weekly. now is the nitty gritty time i hope it not to hit near buds at all. It was 93 in the garden thats supposed to stop pm in its tracks. All the bad clones I got are looking better when not stressed so much. they already yielded last time.
So I went to another forum to find the tricks used for preventing & remediating pm even into flower up to week 2-3. I’ll post it below for everyone.
Courtesy of capulator
The first thing to always consider when setting up and managing a grow is your environment. Environment (Day and night temperatures and day and night humidity) is the most important thing in the grow. If you cannot keep your environment within a desired range, you need to figure out how to do that first and foremost. Please review this thread: https://www.beanbasement.nl/threads/environment-environment-environment.26/#post-80 before going further.
PM thrives in shitty environments. Poor airflow, No filtration, massive sings in day and night temps/RH levels. Reference the above thread, and get your temps and RH consistent and dialed.
If you do not have a carbon scrubber coupled with a fan in the room, get one! They are great at recirculating air and cleaning it at the same time. The bigger the better. You cannot have enough carbon scrubbing IMO.
IPM strategies:
There are 4 things that work very well to prevent and control PM outbreaks in my experience.
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Defolate and prune accordingly. I will post up a thread on how I do that shortly and link it here.
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Microthiol Disperss micronized sulfur (http://www.upi-usa.com/agricultural-products/microthiol), at 3 grams per gallon, sprayed weekly. Works wonders at killing the spores and keeping them dead. Spray plants, floors, walls, ceiling. You can also burn sulfur but I personally like to spray disperss, although I have not had the need in quite some time. DO NOT spray disperss past day 10 of flower. You will not be able to taste the sulfur in the flower, but if you make concentrates your concentrates will taste like shit. Spray with lights off and allow to dry completely before turning back on.
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JMS stylet oil (http://www.stylet-oil.com/Organic-JMS-Stylet-Oil-Specimen-Label-i-88-75.html) at 45 mL per gallon. An excellent choice and currently my go to product coupled with OG Biowar compost teas. Basically mineral oil with an emulsifier, JMS smothers leaves and bugs, killing bugs, disrupting their feeding habits and reproductive cycle, as well as killing PM spores and making it impossible for PM to germinate on the leaf. I spray JMS up to the end of stretch in flower (around day 20), with no ill effects on final flower or concentrate. Spray with lights off and allow to dry completely before turning back on.
IMPORTANT: JMS and Sulfur are incompatible. You need to wait a solid week or 2 between applications or you will damage your plants.
- OG Biowar (www.ogbiowar.com) foliar/root pack coupled with thermx 70, manufactured by http://americanextracts.com as my go to surfactant, or brewed in a compost tea. 15 to 20 grams per gallon of each root and foliar packs and 3mL of thermx per gallon. This is a shameless plug for OG Biowar, but it does work. I have sprayed at week 2 of flower after noticing the very beginnings of a PM outbreak and stopped it in its tracks. Rotating the OGB and JMS is by far my favorite course of action for bugs and PM at the moment, and it is completely safe.
I rotate the OGB and JMS, so that the plants recieve a spray of each one weekly. I make sure defoliations are done on schedule, and that there is lots of air flow. Temps and RH are controlled so that there are not huge day and night swings. I have not seen PM in 2 years.
If you get PM past week 3 of flower, when you should not be spraying anything… you can either trash the whole harvest (something I have done in the past), or you can spray every other day with Oxidate/Zerotol at 40mL/ gal. through harvest. This will wash off spores and kep PM at bay, but you do need to spray frequently and thoroughly, and it is a huge pain in the fucking ass. Again, only speaking for personal experience here. Feel free to share your experience as well, or correct me if you feel I am wrong.
For me, a big part of growing cannabis is growing with integrity. On the old forums, for a long time, eagle20 aka myclobutanil was a go to solution for PM. Unfortunately, many of us used it based on “bro science” ,thinking that it was ok to use. Shit, I used to dunk a cut in eagle before passing it to a friend as a “courtesy” Upside-down face 
… Since then I have learned so much… It is not OK to use, and it will not be condoned here. One good thing about being in a “legal” climate is that I was forced to start testing finished product a long time ago. Eagle20 stays in plant tissue for YEARS. Not months. Not weeks. Do not use it. Do not recommend it to anyone. If you are using it now, stop. I no longer accept cuttings from people because of this. It’s just not worth the fail. You can spray Eagle on a plant and take cuts off it, pass that to a friend… they can grow it out to a mom, and pass it to another friend. That person can grow it out flower it, and it will fail residual testing. No bueno.
Be PM free. Be chem free! Everything is easy when you know how. OK hand 
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Basically what I said above, Sulfur during veg and zerotol in flower.
Just about every grower I’ve known that’s implemented this (including myself) has seen a huge change in the grow.
- Every 7 days hit the room with 4g/ gallon microthiol disperss (you can get a 50 lb bag for like $30 and it’ll last a lifetime.)
- Quit this after week 1 of flower
- If PM pops up use zerotol (oxidate is the same thing, just different use on the pesticide label) at a 1:100 ratio with RO water every three days.
If PM wrecks the grow it isn’t the end of the world. I’ve seen rooms where it looked like it was snowing get budwashed and pass.
- First bucket RO water and lemon juice
- Second bucket baking soda and RO water
- Two more buckets of RO water
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Correct but there’s also multiple ways within that post. I myself would take the ogbiowar & jms route over micronized sulfur as you’ll still be able to taste that sulfur.
In extracts, or smoking the bud itself?
Most definitely in extracts more than the flower. Taste like burnt tortillas. Literally. The flower gets a real harsh ethylene taste to it
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I have never gotten pm in spring but its obvious why= wild temp swings due to a cold spell and the ac vents in teh window. My gardens used to be air cooled hoods and ran ambient now they are led and I run em really hot, but then it got cold out after i put ac in the window so nighttime was cold. it snowed on 4/20. So i switched em to on at night off in day, should work great for summmer.
So standing there dropping my son off at school, and I look at the leaves on the tree (some type of white blossom tree) and wtf do i see. MAJOR and I mean major PM outbreak. 1st time ever seeing PM in real life. Every leaf (or at least 90%+ all had pm
.
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Thankfully, it is a very particular type of PM that attacks cannabis. I was freaked out a few years ago when my squash and cucumbers had an outbreak a few feet from my plants, so I did a bunch of research. Still don’t feel like I know enough, but I became much less worried about transferring random pm from the outside world to my cannabis plants. Living in the PNW, PM is everywhere!
I’ve got some plants in my yard that look like what’s pictured there.
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I counted literally 100+ leaves with pm on just 1 tree. There 8 trees lines in a row. I’m here now to pick him back up. I’ll check the leaves again.
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WTF!
I’ve never seen PM outdoors
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Where you think it comes from?! Haha. Come out to Oregon, and you’ll see it everywhere (plus fight it in every indoor growing environment).
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Yeah, its still there. That’s F’d up! How the heck do you PNW guys handle it
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HEPA filters and good IPM.
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spraying milk and potassium bicarb keeps it at bay. it can prevent ever getting it too. The infection/mycelium is inside the plant, the white spots are just spores from it trying to infest other plants.