Powdery Mildew - Can I use two different fungicides?

Z

zeppobird

New Member
Hello:
I believe I'm in the beginning stages of powdery Mildew. I sprayed with Baking soda once last week but I had to go out of town. I just rec'd some Dr. Earth fungicide which i sprayed on last night. I also have some Green Cure. Can I use the Green Cure after the Dr. Earth? And how often to use these fungicides without hurting the plants?

Thanks!
 
NeWcS

NeWcS

Well-Known Member
Yes, it is best practice to alternate products/ingredients when treating for pests and problems. I like once a week
 
Renfro

Renfro

Well-Known Member
Mohican said:
Lemon juice diluted in water works.
Click to expand...
Thats bad, lemon juice is acidic and that promotes PM. You want an alkaline environment to prevent PM. Thats why Potassium Bicarbonate and Sodium Bicarbonate work so well, they raise the pH not lower it.

I personally mix ALL foliar applications at a pH of 7.5 - 8.0. This slightly alkaline mix won't cause PM if foliar feeding.

I have even seen PM growing on the top of soil or rock wool when the conditions are favorable as the media is slightly acidic.

The best way to prevent PM is to control your environment. There is NO reason to have PM in a climate controlled grow. Allowing lights off temperatures to drop can cause PM because the cooler air holds less water and the RH% spikes. Sometimes it's just as simple as making sure the AC turns off when the lights go out.
 
Sir Napsalot

Sir Napsalot

Well-Known Member
Renfro said:
Thats bad, lemon juice is acidic and that promotes PM. You want an alkaline environment to prevent PM. Thats why Potassium Bicarbonate and Sodium Bicarbonate work so well, they raise the pH not lower it.

I personally mix ALL foliar applications at a pH of 7.5 - 8.0. This slightly alkaline mix won't cause PM if foliar feeding.

I have even seen PM growing on the top of soil or rock wool when the conditions are favorable as the media is slightly acidic.

The best way to prevent PM is to control your environment. There is NO reason to have PM in a climate controlled grow. Allowing lights off temperatures to drop can cause PM because the cooler air holds less water and the RH% spikes. Sometimes it's just as simple as making sure the AC turns off when the lights go out.
Click to expand...
You can control the climate outdoors? Neat!
 
ganga gurl420

ganga gurl420

Well-Known Member
Renfro said:
Thats bad, lemon juice is acidic and that promotes PM. You want an alkaline environment to prevent PM. Thats why Potassium Bicarbonate and Sodium Bicarbonate work so well, they raise the pH not lower it.

I personally mix ALL foliar applications at a pH of 7.5 - 8.0. This slightly alkaline mix won't cause PM if foliar feeding.

I have even seen PM growing on the top of soil or rock wool when the conditions are favorable as the media is slightly acidic.

The best way to prevent PM is to control your environment. There is NO reason to have PM in a climate controlled grow. Allowing lights off temperatures to drop can cause PM because the cooler air holds less water and the RH% spikes. Sometimes it's just as simple as making sure the AC turns off when the lights go out.
Click to expand...
Very true... well except for the control of the outdoor environment.
 
Rob Roy

Rob Roy

Well-Known Member
I've had good luck controlling powdery mildew with sulfur spraying. Side benefit is it messes up spider mites too.

It's available in concentrated liquid or as a powder (which you dilute) at big box stores and garden supply places. Many brands have pyrethrin added. So wear a dust mask. I add a few drops of Dawn for a surfactant. If you overdo it, it can burn plants. Wouldn't spray seedlings or young clones with it either. Wouldn't use after the 3rd week in flower, maybe even the 2nd week depending on bud formation etc.

Outdoors I use alcohol and try not to hit the buds.
 
CanadianJim

CanadianJim

Well-Known Member
H2O2 (hydrogen peroxide) will kill pretty much any mold, but as it breaks down into water it'll end up soaking your buds again. If you do it in the morning maybe the sun will dry them off, and if you're getting soaked with dew anyway I would say it's worth a shot. I also don't know if it damages trichomes or not.
For powdery mildew I use potassium bicarbonate, and it is also good for prevention of budrot. If you have a really bad pm infection you can wash your buds at harvest.
 
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