Powdery Mildew control

Uncle Ben

Well-Known Member
Just wrote this in a PM to another grower. Since I spent some time on it thought I'd repeat it here. Question was, "Uncle Ben, have you ever had PM problems and if so, how did you control them?"

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Never on cannabis but I do spray, rarely, PM control products on squash or cukes. I also have a broad spectrum spray program for grapes which includes PM control. Based on the 2014 Spray guide for Texas grape growers here are the most effective, food safe, products recommended for PM:

Pristine - a topical and systemic 'silver bullet', but very expensive. My fave. I mix it with Rally, see below.

Myclobutanil - that is the active ingredient found under many names. Cheap and another one of those "silver bullets". Rally 40WSP is a commercial product I use. Price may be high but a little goes a lonnnnnnnng way as it contains 40% of the AI, active ingredient. Hardware stores will have mcylo. It will also control black rot, leaf blight and many other diseases. If you do any other type of gardening or have turf problems, this one is the one to have on hand. The over the counter products are a rip off, like this one at only .78% of the AI. http://www.ebay.com/itm/SCHULTZ-FUNGICIDE-PLUS-CONCENTRATE-Disease-Plus-Insect-Control-16-fl-oz-Bottle-/190947134508?pt=LH_DefaultDomain_0&hash=item2c75560c2c

This is THE cheapest way to go at 20% AI (active ingredient) - http://www.ebay.com/itm/Eagle-20EW-Fungicide-1-Pint-/231008032597?pt=LH_DefaultDomain_0&hash=item35c926d755 Post harvest interval is 14 days. Only 1.5 ml/gal.....include a surfactant. (That calculation is based on a recommended rate of 5 oz/100 gals.)

Quinoxyfen

Sulfur, although I don't think your buds will smell/taste so good.
 

bird mcbride

Well-Known Member
I would note that burning sulfer around mj can cause problems with babies still in the womb. I know pregnant women should not smoke but some do.
 

gaiaman

Member
i dont use systemics or non organic fungicides, i found that sulfur works extremely well as preventative,on big veg plants, before flower, once flowering, H202 solution or lemon juice solution work well if you catch it in time.
 

Southerner

Well-Known Member
Keep RH below 60%.

Also, why is that I always see PM on squash plants in peoples garden boxes when I walk around the neighborhood in Summer. Is that plant especially susceptible?
 

dudeoflife

Well-Known Member
Worth mentioning: Seaweed extract inhibits fungal growth- to a degree.

Although it wouldn't take down an already existing problem, it is good for preventative maintenance, and can be used in a foliar spray, too.
 

colonuggs

Well-Known Member
living in Washington state by a lake ...pm is on all the bushes trees almost everything..... I have never been able to 100% get rid of pm only manage it ...Greencure or h202

Silicone is good a preventative....Einstein oil too

......ahhhhhhh the smell of rotten eggs in the morning....love sulfur vapes :) NOT
 

dudeoflife

Well-Known Member
living in Washington state by a lake ...pm is on all the bushes trees almost everything..... I have never been able to 100% get rid of pm only manage it ...Greencure or h202

Silicone is good a preventative

......ahhhhhhh the smell of rotten eggs in the morning....love sulfur vapes :)
+1 for Silicon supplement (Silicone is the manmade version)

My .02:

Really though, I would use the above mentioned chems as a last resort (which I think was the intention of this post) for outdoors.

For growing pot indoors I would advise on keeping the emphasis on proper growing conditions.
 

OGEvilgenius

Well-Known Member
First prevention is healthy plants. If your plant is completely healthy there's little chance it will develop PM.
 

HrilL

Active Member
I had PM once a long time ago on some free clones I got. They had no signs when I got them but it showed up soon afterward. it hit my garden pretty hard. Filled a 32 gallon trash can with Eagle 20 and dipped every plant for 30 seconds. After that I've never had pm again. Systemic killers is the way to go. I wouldn't use anything like that close to flower though. I vegged those plants for another month before they went into flower so I was pretty sure by the time they were done everything was done. Definitely works good though.

Apply it and clean the shit out of your whole grow area with a bleach and water mix.
 

homebrew420

Well-Known Member
Most effective,
burn sulfur. No poor flavors or residual. 1 burner will cover close to 1000sqft. 3 ft or so from canopy no fans. Vent before lights on. No oil sprays for a week to a month.
Eagle20
Heritage
Quintet
Regalia.
these work perfect. And I question the need for chems when burning sulphur.

Peace
 

LIBERTYCHICKEN

Well-Known Member
Worth mentioning: Seaweed extract inhibits fungal growth- to a degree.

Although it wouldn't take down an already existing problem, it is good for preventative maintenance, and can be used in a foliar spray, too.

Garlic will work alot better than seeweed , Just make sure the plants are dry before nightfall
 

SnapsProvolone

Well-Known Member
Wouldn't trade my sulfur vaporizer for anything. Never had it change flavor of buds, imho that's a myth held by those that have not used them.

Have used Eagle 20 as a veg dip, but in large grows the S vape is the way to go imo.
 

LIBERTYCHICKEN

Well-Known Member
Never used horsetail, but it is said to have a high concentration of Silicon's , some are said to also contain nicotine and related chemicals
 

corners

Well-Known Member
it ends up on most of the tomato plants in the north east also when ti starts to get cool.
 

Peacebud420

New Member
E20 before flower, these nugs safe to smoke? Anyone else use this as preventative n have their stuff turn out okay? These buds safe?mthanks!
 
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