Powdery Mildew - Washington peeps

[Farmer Rich]

Any of you Washingtonians having difficulty with powdery mildew lately? I hear a lot of folks are.

Only appears in my flower room so far and I'm hitting it with a baking soda solution to try and at least retard it. Also have about 1/2 the room nearly ready to chop so I'm going to accelerate by a few days as much as I hate to. Any other suggestions? Anyone using a sulphur burner?

Peace,

Farmer Rich

Farmer Rich Reviewed by Farmer Rich on 12-04-2010. Powdery Mildew - Washington peeps Any of you Washingtonians having difficulty with powdery mildew lately? I hear a lot of folks are. Only appears in my flower room so far and I'm hitting it with a baking soda solution to try and at least retard it. Also have about 1/2 the room nearly ready to chop so I'm going to accelerate by a few days as much as I hate to. Any other suggestions? Anyone using a sulphur burner? Peace, Farmer Rich Rating: 5

[copobo]

eagle 20 is the only real cure for PM.

spray once or twice in veg and you will never see pm again.

It's not organic, but it's immobile (so it wont get in your buds if you only use in veg). It is used in the fruit industry. If I use in veg, I never see the PM in flower.

I fought that crap for 6 months and tried every organic method I could find (neem,serenade,baking soda...) and had environmental controls down, once that crap is in your room... there is no other great way to get it out. A sulfer burner will help, and it's good to use to change the surface environment, but the PM is IN the plant tissue.

you can find small (1 oz) containers on ebay. the $60 container has enough for 2 lifetimes. It takes something like 1/4 teaspoon per gallon, IIRC.

best of luck

[gypski]

eagle 20 is the only real cure for PM.

spray once or twice in veg and you will never see pm again.

It's not organic, but it's immobile (so it wont get in your buds if you only use in veg). It is used in the fruit industry. If I use in veg, I never see the PM in flower.

I fought that crap for 6 months and tried every organic method I could find (neem,serenade,baking soda...) and had environmental controls down, once that crap is in your room... there is no other great way to get it out. A sulfer burner will help, and it's good to use to change the surface environment, but the PM is IN the plant tissue.

you can find small (1 oz) containers on ebay. the $60 container has enough for 2 lifetimes. It takes something like 1/4 teaspoon per gallon, IIRC.

best of luck

Well, this is good news because this year it was a MFer outdoors. It was everywhere. At that price, a couple people could go in on a bottle if it goes that far. :thumbsup: No problem with it indoors, so far and the clones I took from the out door weren't infected. No bugs either or other pest besides neighbors.

[Farmer Rich]

Hey Copobo,

Thanks for the advice on Eagle 20, I'm going to give it a shot in my veg room just to make sure none of my new ones are affected..

Peace,

Farmer Rich

[WashougalWonder]

How many CFM of vent air for how many square feet of room?

[Farmer Rich]

Hey Washougal,

84.5 sq. ft, 676 cubic feet, 450 cfm vent fan. Also have 2 fans running for air circulation... been running temps (lights on) of about 76-80 with a humidity of 45-55%. Lights off, it does drop to about 63. I've I read powdery mildew thrives with these environmental factors.. good for cannabis, good for PM.

From what I'm seeing so far, the baking soda mixture (4-5 tsp : 10-12 oz water) seems to have worked well for the time being. No new signs, though I'm considering hitting the plants in veg with a fungicide as a prophylaxis to prevent any recurrence. I was going for the Eagle 20 Copobo mentioned, but my other 1/2 is on my case and thinks I should use the neem oil she has in the garage vs. buying another product. Anyone have any experience treating PM with neem oil?

Peace,

Farmer Rich

[WashougalWonder]

I don't think neem has any antifungicidal effects. I love the stuff, but don't think it would help.

The baking soda is a very benign (to us) method if it keeps it under control, costs little and best of all will keep the whining half happy, which overall makes life so much better....took 20 years of marriage to learn that tho...lol

Great venting. Curious why I have not had the problem?

[Farmer Rich]

Hey Washougal,

Yeah, I mentioned that I didn't think Neem oil is used as a fungicide.. about 2 minutes later I was being shown the bottle where it noted it also works as a fungicide. Go figure..

Anyway, the baking soda appears to have curtailed the PM I found, though I'm continuing to watch like a hawk. Be interested to hear if you experience any probs. The rumors of PM problems I was hearing were in the Tacoma area..

Peace,

Farmer Rich

[rudy2010]

I am going to have to give the baking soda a try for PM. I have been using the Safer product that addresses that issue successfully but baking soda seems more organic.

[Farmer Rich]

My wife did a bit of general research and also found that combining neem oil with a treatment of baking soda is reported to work well. Seems to me you'd apply the baking soda/water followed up by neem oil after the baking soda drys a bit. In my case it didn't seem to take long, maybe 1/2 hour with the lights on.. I also think I was pretty liberal with the baking soda and next time would cut it back some. With plants in flower, probably best to focus low and avoid the buds if possible. So far no negative effects on the plants in flower that are nearing the end of week 4.. I also flipped 4 more plants yesterday and am watching them closely to make sure PM doesn't magically appear. Currently they're looking clean and haven't been treated with the above.

FR