Powdery mildew on leaves of flowering plants

I have been dealing with this PM on my leaves for about a week. Plants are about 3 weeks into flower and producing very well. I doused them pretty well with straight 3% hydrogen peroxide about 5 days ago and have been spot treating them every couple days with the same 3% h2o2. Plants are in dwc setup, fed half strength GH trio and treated with Hydrogaurd. I have trimmed them down more and increased the air circulation.
This PM just keeps returning. It’s not getting worse really, it just seems to come back a day or so after treatment. I can’t imagine spot treating this problem for the next 5-7 weeks, although I will if that’s the only option. I have read about many ways to treat PM like this, but almost none address whether the treatment can be used on flowering plants or they say that you can’t use it on flowering plants at all.
What else can I treat this with besides h2o2? Is organic apple cider vinegar more effective and safe to spray on flowers? I have read about adding calflex to the res to add calcium to the leaf structures to help make them less susceptible.
Please help! This h2o2 treatment seems to barely keep this PM at bay. Thanks!!

I dont know about the vinegar if it would work or not so I cant comment on that= I wouldnt use that myself.

Try a silica spray the high ph will kill the mold i believe and the silica will help heal the plant and keep the pm at bay. Get your humidity down to 45-50% . And when you spray you have to cover the entire plant like you would for spider mites no need to miss a spot and have it come back.

Never heard of the calflex product either but amino acid will help with the calcium uptake and the calcium will make the cells stronger or something like that I cant remember what really off hand sorry I forget what exactly, but yeah your on to something by making sure your plant has plenty of calcium available. I think Iearnt that from the harley smith videos on the yutub

PM wash has worked for me in the past and will probably work for me tomorrow too = I got some pm on some clones.

High humidity itself doesnt cause PM, big swings in RH or temperature can trigger PM spores to start fruiting. If you are on week 3 you are getting to the point where you shouldnt be spraying anything on your flowers.
Regalia by marrone bio innovations works extremely well as a preventative and approved for cannabis use by Oregon and California. You need to knock back the existing PM first before you apply regalia, people use all sorts of shit for that....milk, h2o2, silica (pro-tekt or agsil), oils, etc.
The h2o2 is going to oxidize your trichomes and make your buds get brown faster.
In your case I would probably cut out any infected leaves, spot treat with h202 as best as I could and then hit it with regalia every couple of days.

Lol yes it was Harley smith!

I have read about using silica as well. I will look into this more. What silica product should I spray them with?
Thanks for the reply!

for foliar i would use use dynagro pro-tek silica = basically any good brand

Cool thanks. Regalia looks pretty neat. Kinda pricy, but it’s worth it if it keeps this PM away.

If you have a healthy plant and some sort of decent environment that doesnt scream hey PM over here you dont need to worry about it too much. Myself I am going to PM wash mine then just use a silica spray a few times or till they get going and strong and I know I will have it beat, easy peasy.

Yes, overall they are very healthy plants in an environment that’s been grown in before without one spore of PM. I will get some silica spray to keep it at bay. Hopefully that won’t oxidize my buds like the h2o2.

Good advice and to be safe you can bathe the bud once chopped in a peroxide solution of peroxide and water to get any at harvest. Works great, trimming is actually easier as it gets super crisp w water absorbtion... dries as normal, smakes dandy... this is insurance and some assistance not making bud covered in it brand new again

No degredation in quality from wash? I have read about this.

Redheadeight said:

No degredation in quality from wash? I have read about this.

Click to expand...

I was happy w end product when i did it... look, smell and effect seemed the same in the end.. Jorge Civantas has videos on doing it... i was concerned too but with a lil bit of pm id fought off i was worried about that too..perfect quality was already done for that round... but i have no complaints in how it turned out after the dunk..

It kinda makes sense tho, the good stuff on our girls isnt water soluble... otherwise outdoor plants would be ruined by rain or you would be able to wash your hands w water only after training or trimming and be good...

Groovy. Thanks a lot guys!
I picked up some GH Armor Si. Gonna douse them all well with it and then spot treat as necessary. Hopefully this will clear up this PM better and it won’t damage the flowers that are growing. Also gonna add to the res’s @ 1/2tsp/gal.

I just use GreenCure. People using and recommending silica spray what brand do you use? Is it premixed or do you have to mix it. I’ve never seen or used it. Ty

With pm adjusting the leafs pH is what's happening with the use of green cure, or baking soda. Another option is to just adjust the pH and use a sticking agent. pH up and cocowet along with some good beneficials. Beneficials create a healthy environment on the plant itself. I use regalia and silica religiously on my commercial grows.