Eagle 20? Why?

Tablespoon of vinegar to 16oz of water is effective against PM. Those here saying that powdery mildew is the result of an environmental problem are also correct.

PJ Diaz said:

I haven't used the stuff for years (because it's nasty), but Myclobutanil definitely works. I had a cut which the mother had developed PM, so passed it on to cuts taken from her even when she wasn't showing symptoms. There is an over-the-counter version of Myclobutanil which isn't Eagle20. I sprayed a couple of freshly rooted clones with the stuff and never saw PM in future clones taken from new mothers again. I don't really suggest it, but there's only two ways I know of getting rid of systemic PM for good, and that's Myclobutanil or tissue culture. Most people would rather spray the plant than mess around with tissue culture.

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PioneerValleyOG said:

yes, systemic was the word. the guy had sprayed weeks even months before and was advised, because he was forced to harvest early, to trash the whole crop. something about it changing your dna?

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Metasynth said:

Myclobutanil is a known reproductive inhibitor. It’s also widely used on strawberries and on golf courses.

To answer the question “why”...it’s simply the only actual cure for PM. Because it’s systemic, it rids the plant of PM, instead of slapping a band aid on it.

Still, I used it once, then did some more reading and trashed the crop a couple hours later.

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The whole "systemic" thing is a rather interesting argument.

The spores are basically everywhere. They get the right environmental conditions, they pop!
"roots" from this mold do get into the tissue structure of the plant - IF LEFT UNCHECKED.
This seems to me to be the basis for the systemic argument.

Point being, unless you kill the "roots" it will come back...

Next thing
You can use the chemical but,,,,it will allow the infection to return in time. The active chemical half life does run out.

While not my favorite solution... To me, the "end all, do all" PM solution is?
Buy a sulfur burner and use it for 12 hrs a night for 2 nights. In bigger then a 24x24 area? You may need to ,increase the treatment's and/or, move the burner around the op.
You MUST then sanitize the whole grow op. Use a bleach solution or a high % H202 solution. Thing is. if you did the "burn" properly. That kills any spores around too. Must be done for long exposures and in consecutive nights.

Horse tail grass tea, mixed with about a tsp of Green Cure or Sodium Bicarb (as a water surface tension breaker) is very effective.

Thing is the spores are everywhere and it will return in about 14 days.. Same for any surface pH changing "cure".

PM outside?

I've never had it outside!

I do NOT believe that PM is really systemic..period! It only attacks where spores hatch...Does not spread by one spot internally and then through out the plant...