So even though it is still a free country and folks can choose what they want to eat or smoke, to recommend an effective "organic" cure to an already infected crop is labor intensive, spray intensive, ineffective and insane.
OP asked for preventative measures. I provided him a link to some non-toxic options. Just wondering if you have tried lactobacillus on PM to know whether it is effective or not? Have you tried liquid silca as a preventative measure? I haven't as I don't have to contend with PM, but I trust the posters I referenced on this one.
BTW - I'm not sure if you read OPs original post. It seems he is fine in veg, but once plants get into flower and he stops spraying with Senenade (lactobacilus) he gets PM. Thus, he doesn't have an "already infected crop".
I just finished my third grow with some sub average results.
I also spray from veg to first few weeks of flowering with Serenade, which works great, but of once I stop the PM comes back with a vengeance.
And with what? Any other preventative measures that I can do?