What kills white powdery mildew?

that far into flower im sorry to hear that . have had that problem almost exact. and imo there is only a couple things you can do.the best option is a sulphur burner.
the next option is a large dehumidyfier and drop the hunidity as low as yoy can get it.
thi dry humidity will also increase trichs.

1 part skim milk to 9 parts water, spray it on the problem areas.

thanks for the input. I think i will try both methods.

i have this months High Times, and theres a question the Jorge's RX section about powdery mildew. Q. "i have your book, marijuana horticulture (aka "the bible"). i also have powdery mildew. im an organic garnder. help!"

A. "you know the unpleasent news from reading marijuana Horticulture. once powdery mildew sets in, it continues to grow untill it destroys the plant..." and he goes on about it becoming more of a problem here of late and says prevention is key. once you see the first indication of infection,small spots on top leaves, the disease has been inside the plant for a week or more. he also goes on to say its occasionally fatal indoors, and is at its worse when roots dry out and foliage is moist. also avoid excess nitrogen. copper and sulfer-lime sprays are a good prophylactic. for bio controll, apply Serenade or spray with a mixture of baking soda and water, the baking soda dries out on the leaf and raises the surface ph to 7 and powdery mildew can no grow. bordeaux sprays also help keep the mold in check.

i can take no credit for this info. its straight from the man himself...

I have "the bible" and it says controlling humidity is the way to helpn not solve, the problem. So i will take a look into "serenade". Thanks.

can someone tell me the proper way to spray for powdery mildew with being 2 to 3 weeks from harvest

Sulpher burner!

Nothing but a sulfur buner kills that shit.Only thing that put it in check was water at a ph of 9 to 10,but spray early in the light cycle.