Chronic Powdery Mildew Problems

[grapeman]

Fighting it for over 40 years and he's still got it? I got rid of it in 10 minutes.

LOL - freezerboy.

I think I deal with a few more varibles in the great outdoors then you might. Plus it's a seasonal thing.

I haven't had PM indoors for about 2 years or so, nor have I had a need to spray for it. But I do know a bit more about it then you.

BTW - the thread title is "Chronic PM Problems", which leads me to believe that he already has a problem, and needs a cure and not a prayer.

 

[pinecone]

To be quite honest, I would take grapemans advice (who has been battling PM for over 40 years) over pinecones (who just admitted he has no real-world experience with PM). I trust experience, not second hand info.

I realize this is a fine line, but I didn't give advice. I simply said what I would do in a similar situation. I would, under no circumstances (rare genetics or not), be using Eagle 20. I would be cleaning up, throwing out plants if necessary, and looking for a non-toxic remedy. Take it for what it is. I would not smoke plants that Eagle 20 was used on. Avoiding things like Eagle 20 and the other crap commercial growers spray on their crops is the reason I grow my own.

Additionally, I might not have any experience with PM, but authors of the two post I referenced have a lot of experience with PM indoors.

Pine

I personally wouldn't use Eagle 20 or smoke any buds that it was used on. Organic growers from the Pacific Northwest, where PM is a persistent problem, have other ways to deal with PM. For some ideas see the following thread - particularly post by Capt. Cheeze1 and CC2_U.

https://www.icmag.com/ic/showthread.php?t=214561

Pine

 

[paladin420]

Here is something that I found pretty darn interesting...

Guy was in here talking about killing his mold at end of week 5, flower... basically screwed for options. He asked me about a product called Kagen water... did some research... Kangen Water... or rather a form of ionized water that produces both very alkaline & very acidic waters.

Based on preliminary searches... bacteria & mold apparently die at 2.5 & lower acidity ranges... with normal water. There is apparently a university study showing something to this effect... can't find it yet. Anyway, got me thinking about that PMWash stuff... frequency enhanced water... sure as shit, it measures 2.4 pH.


Anyone heard of 2.5 acidic water & treating for mold before?

I hav used PM wash. On Buds as they finish. Very good shit. Kills nicely on contact. seems to stop or slow spread.

Not to get in an organic pissin match. But this seems pertty harmless to me. Anyone kno why I should not spray an flowers??

 

[paladin420]

TRY THE PM WASH OP..

 

[BudGood]

pinecone, do you have any clone-only strains? Or have you popped all your stuff from seed? Because I hate to tell ya this, but the chances that Eagle20, Forbid, Floramite, Avid, etc has been sprayed on the plants are pretty good. Any person who isn't stuck on organic and natural methods only will use the most effective tool to kill/control with.

Don't get me wrong, I love organic herb, but I'm not gonna let pests or PM screw up my grow (which not killing the PM could be even MORE toxic to patients with compromised immune systems than ANY chemical ever could be).

It's pretty simple:

-Follow IPM principles, never use the same product twice to prevent resistance.

-Use the correct dosage, too much or too little can both be a problem.

-Never spray in flowering, only in veg, and veg treated plants for an extra 2-3 weeks, to make sure all chemicals dissipate properly.

-Clean and sanitize room in between runs, Physan20 is your friend.

 

[pinecone]

pinecone, do you have any clone-only strains? Or have you popped all your stuff from seed? Because I hate to tell ya this, but the chances that Eagle20, Forbid, Floramite, Avid, etc has been sprayed on the plants are pretty good.

I can assure you than none of the products you listed has ever been sprayed on my plants. Additionally, Eagle 20 isn't on any of my orchard fruit or nuts.

Follow IPM principles

For me this would mean first and foremost cleaning up and secondly using lacto b, neem, and silca as a preventative measure. For me (and some others if you read the thread I linked) Eagle 20 would not be worth the risk. But to each their own.

I just wanted to get OP and whomever else was reading this some options for alternate controls so they aren't led to believe they have to use something like Eagle 20. The active ingredient in Eagle 20 is called myclobutanil. My advice to anyone would be to their research on non-pot forums before using it; Make an informed decision.

Pine

 

[grapeman]

I double checked before I posted. The OP was asking for help in a grow forum that was not in the Organic area.

So all advice here from everyone is legit.

 

[spadedNfaded]

Im going to have to go with Eagle 20 on this as well.

Plenty of research, plenty of successful documents, and available = no brainer.

mix at the recommended rate, apply in veg, never see PM again.

If the chemical breaks down in 4 weeks and is applied at the onset-14 days into flower you shouldn't have any of it left in the harvested plant.

Im sure going outside and breathing air contains more contaminants and harmful chemicals than a safely harvested plant that has been sprayed with Eagle 20 10 weeks prior.

I had PM for a month, battling it, beating up my ladies, dunking, spraying, cutting.....My battle was won in ONE day when i sanitized my veg area and applied Eagle 20.

- SubN

 

[dgr]

grapeman,
If you decide (hint, hint) to do a write up of current chemical IPM strategy for PM, please let me know. I'd enjoy reading a discussion on Tebuconazole, Myclobutanil, etc. I notice no one in here recommends any product rotation. Seems like a not so great path to go down.

 

[BudGood]

It's pretty simple:

-Follow IPM principles, never use the same product twice to prevent resistance.

I notice no one in here recommends any product rotation. Seems like a not so great path to go down.

Really? I think you need to read a bit closer. Look above.

 

[dgr]

Really? I think you need to read a bit closer. Look above.

BudGood,
You're right. It's dangerous ground to speak in absolute terms. I'm busted. Here's a re-write.
I support the use of myclobutanil as a PM preventative. The anecdotal evidence gathered on this board suggests that it is a very good, seemingly permanent, solution to this problem. However, I am a bit concerned that many people advocating the use of myclobutanil don't seem to be following standard PMI practices such as product rotation. I'd hate to see the home growers create a super strain of PM, which seems to what has happened with rose fungal infections.

I'd like a better understanding of the dangers of not doing so and the proper procedures when trying to follow PMI best practices. For example, would proper PMI be rotating application between myclobutanil and tebuconazole or would we be better rotating between myclobutanil and trifloxystrobin? The difference between those two scenarios being the mode of action being the same in the first example and different in the second. Or is rotating between sulfur and any of the sterol inhibitors and strombilurins the appropriate management strategy?

That being said, I'm interested in input from anyone that understands and accepts the "risks" involved in using chemical treatment methodology to prevent crop damage from PM. I'm particularly interested in the opinion of people that are combating this in a more extreme environment and have to follow regulations as to yearly application rate, P.M.I and R.E.I. IOW, commercial growers deal with this on a much larger scale, throughout the growing season and on a yearly basis.

NOTE: Those are some big chemistry words. They aren't mine but pulled from a UC Davis paper on PMI that leaves some questions in my mind.

 

[grapeman]

grapeman,
If you decide (hint, hint) to do a write up of current chemical IPM strategy for PM, please let me know. I'd enjoy reading a discussion on Tebuconazole, Myclobutanil, etc. I notice no one in here recommends any product rotation. Seems like a not so great path to go down.

In my day job, I rotate fungicides. Always. Never have PM.

Here, since i have a PM problem so rarely, I don't find it necessary. If I did have a PM problem, I would certainly rotate products. Be mindful in rotation to use products with different modes of action for best results. I've been posting in krunchbubble's thread for over a year reminding these guys with PM problems to rotate their fungicides. If one does not, one day they will have a strain that they cannot control.

BTW, if I ever see PM, I treat in veg. Once treated in veg, I have never seen PM in flower.
Honestly, I've never used Eagle. I have access to other fungicides that need an applicators license to procure.

But since most here love Eagle, I guess it is a good fungicide,

I rotate Rally, Flint, Elite, Bayleton, Pristine and others. I always apply Champ in the winter which is a copper based fungicide for use in dormancy.

But believe me when I say, foliar applications of anything go a long way in controlling PM as H2O kills PM spores on contact. Complete coverage is key.

 

[eastcoastedge]

when i saw this post it brought back alot of bad memories,for yrs never ever had PM then i got a clone from a friend and for the next year we tried every thing out there that you could by at the gardening shops and some worked better than others but not one of them would get rid of the PM,then i found a post on here about SULFUR BURNERS and i did a bunch of reserch and ended up building one myself from a 6" resesed light fixture with a green floodlight 100w,it took some messn with to get the temp between 285/350 but it turned out to work unbelieviable it was the only thing that would kill the PM,you dont want to run it when the light is on,and dont want to run it after day 35 at the latest,but i would highly recommend buying or building one,you will never have a good cycle intil you get rid if the PM,its by far the worst stuff iv ever seen to get in your garden,and some strands will get it and iv seen different strand right next to it not have any signs of it at all,we ended up having nycd and ak47 and only the ak47 would get the mold issues so we just got rid of the ak47 just to be safe and between getn rid of the strand and the sulfur burner the problem is history....... thank GOD/SULFUR BURNER

 

[greenmatter]

In my day job, I rotate fungicides. Always. Never have PM.

Here, since i have a PM problem so rarely, I don't find it necessary. If I did have a PM problem, I would certainly rotate products. Be mindful in rotation to use products with different modes of action for best results. I've been posting in krunchbubble's thread for over a year reminding these guys with PM problems to rotate their fungicides. If one does not, one day they will have a strain that they cannot control.

BTW, if I ever see PM, I treat in veg. Once treated in veg, I have never seen PM in flower.
Honestly, I've never used Eagle. I have access to other fungicides that need an applicators license to procure.

But since most here love Eagle, I guess it is a good fungicide,

I rotate Rally, Flint, Elite, Bayleton, Pristine and others. I always apply Champ in the winter which is a copper based fungicide for use in dormancy.

But believe me when I say, foliar applications of anything go a long way in controlling PM as H2O kills PM spores on contact. Complete coverage is key.

cool grape.... you do know a lot more about the different fungicides than we do. but we can't get what you do. so with what we can all get our hands on what would you do to follow a sensible rotation. i have read that neem is recommended as one of the steps in a rotation against powdery mildew, but having tried to cure pm with neem i kinda scratch my head when i read that. knowing what you know about pm what should we all have on the shelf so we don't help breed a super fungi. is there anything else we can get our hands on that KILLS the stuff? i have only had to use eagle one time, but when i did i really needed it to work. i don't even want to think about a pm that is immune to that stuff.

 

[eastcoastedge]

 

[eastcoastedge]

its not the best picture but it was the only thing we found that would kill PM,and we tried everything,the sulfur sits in the can cut in half that is saspended just above the 100w green flood light,the can heats up to 325 degrees,if you decide to build one like i did make sure you do some heat tests to get the proper heat,i used 2 round plates 1/8" thick with a hole in it 3" hole drilled out so the can can fit and be suspended about the light and the plates help to hold the heat in ,i drill holes in the can with a bolt n nut sticking out to hold the can up off the bulb,the different holes in the can are for adjustment of the can up n down in 1/4" incoments,to get the proper temp my can ended up being about 3/8" off the bulb,hope this is some useful info that will help someone??

 

[greenmatter]

don't know eastcoast .... from what i have seen a sulfur burner will knock back the pm but it does not cure it. how long after you shut your burner off do you start to see spots on plants that were infected?

 

[eastcoastedge]

the trick is to run the burner before the plants are infected and you wont have a problem,the sulfur didnt have any other side effects to the garden,i was really nervious about running it for the first time but after trying it out for a couple hrs and waiting a couple days to see if there was going to be any side effects,we kept running it for longer periods of time,if u are running it before you have the issue,i run it for 2/3 hrs a couple times a week and if you are running it after the PM is the issue i run it for 6/8 hrs 3/4 times a week,this thing was the only thing that would keep the pm under control,we tried multi different sprays and powders and not one of them kept the PM undercontrol,but everyone has a opion but this is what worked for me after trying everything it seemed like...

 

[grapeman]

cool grape.... you do know a lot more about the different fungicides than we do. but we can't get what you do. so with what we can all get our hands on what would you do to follow a sensible rotation. i have read that neem is recommended as one of the steps in a rotation against powdery mildew, but having tried to cure pm with neem i kinda scratch my head when i read that. knowing what you know about pm what should we all have on the shelf so we don't help breed a super fungi. is there anything else we can get our hands on that KILLS the stuff? i have only had to use eagle one time, but when i did i really needed it to work. i don't even want to think about a pm that is immune to that stuff.

You guys can get Eagle. I do spray neem (along with other foliar amendments) weekly in veg thru week 3 or 4, depending on the strain. I do use phosphites also as a foliar in the mix. Pure flowers is the product name.

The advantage of this product is 2 fold. I does enhance P a bit in the plant and it is proven to have fungicidal properties. It's like having another product in rotation.

 

[grapeman]

don't know eastcoast .... from what i have seen a sulfur burner will knock back the pm but it does not cure it. how long after you shut your burner off do you start to see spots on plants that were infected?

Repeated applications of wettable sulfur can win the battle..... but rarely. Sulfur burners duplicate applied sulfur in 95+ degree climate via fuming. It can work and kudos to anyone who has 100% success on battling PM with a sulfur burner alone.

I wouldn't risk it myself any longer since one can easily get safe products for cheap that work better.