Outdoors season and powdery mildew. Any solution?
- Thread starter Rblade
- Start date
graying.geek
Well-Known Member
Mix 3 tbsp. of potassium bicarbonate, or better: ammonium bicarb, 3 tbsp. vegetable oil, and 1/2 tsp. dish soap into a gallon of water. Spray onto affected plants.
Rblade
Well-Known Member
don´t change the flavour of the herbs? They have one month in flower
Jimbo the Gael
Well-Known Member
That measurement for potassium bicarbonate is a bit high. Even Green Cure, which is about 85% potassium bicarbonate is only 1tbsp per gallon, and a full strength dose will turn your pistils brown.
When I use pure potassium bicarbonate I use a teaspoon per gallon, with a surfactant. It still works.
I haven't noticed any change in the taste of the buds, but as they're outdoor I wash them anyway.
Edit: went with vimeo instead of youtube, age restriction bs. I'm not starting a channel just to watch a video, and nobody should have to
When I use pure potassium bicarbonate I use a teaspoon per gallon, with a surfactant. It still works.
I haven't noticed any change in the taste of the buds, but as they're outdoor I wash them anyway.
Edit: went with vimeo instead of youtube, age restriction bs. I'm not starting a channel just to watch a video, and nobody should have to
Rblade
Well-Known Member
sodium bicarbonate not works?
Jimbo the Gael
Well-Known Member
Sodium bicarbonate works, but potassium bicarbonate raises the ph of the leaf surface more. Raising the ph of the leaf surface causes the cell walls of the fungus causing the powdery mildew to burst, killing it. I don't know anything about ammonium bicarbonate.
One word of caution, some of the potassium bicarbonate can be absorbed by the leaves, acting as a foliar feed. If your nutes are already high in potassium that can cause an issue.
One word of caution, some of the potassium bicarbonate can be absorbed by the leaves, acting as a foliar feed. If your nutes are already high in potassium that can cause an issue.
graying.geek
Well-Known Member
My regrets to the community for posting a treatment that is potentially damaging to your plants. I was WAY off on the concentration, which I have to look up every time I mix a batch, but failed to do so before posting above. The research from these articles provides guidance:
They provide strong evidence that bicarbonate salts are effective in prevention of botrytis and PM, but Potassium or Ammonium Bicarb in concentrations of 75 and 25 mM concentrations respectively provided 100% inhibition in their tests. Based on this, I mix 2 g (NH4)HCO3 with 1 liter H2O. This works great alone for prevention and remediation, but I'll generally add a tsp each of dish soap and sesame oil, and 1/4 cu isopropyl alchohol for general fungal and spider mite control
They provide strong evidence that bicarbonate salts are effective in prevention of botrytis and PM, but Potassium or Ammonium Bicarb in concentrations of 75 and 25 mM concentrations respectively provided 100% inhibition in their tests. Based on this, I mix 2 g (NH4)HCO3 with 1 liter H2O. This works great alone for prevention and remediation, but I'll generally add a tsp each of dish soap and sesame oil, and 1/4 cu isopropyl alchohol for general fungal and spider mite control
growslut
Well-Known Member
Try Regalia. Game changer. It got rid of mildew just by watering it into the soil every 2 weeks. Its a preventative so probably too late for this current crop. You have to start using it before there is an outbreak, so next round give it a try.
JimmiP
Well-Known Member
I was going to say your concentration seemed a little high. But anyway the stuff works wonders.
Silica can also be added to the foliar spray and can be fed to the plants during watering. It, silica, will help strengthen cell walls making the whole plant less susceptible to infections.
Rblade
Well-Known Member
Silica, like silica bag for humidity? the same which you can found in the electronic boxes?
Rdickenson
Well-Known Member
Excellent,knowledgable answer!!!
Jimbo the Gael
Well-Known Member
Not quite. There are silica supplements available, and it's in a lot of nutrient mixes as it strengthens stems. It's present in most soil, but it's not really in a form that plants can absorb efficiently. Liquid supplements are readily available to plants.
JimmiP
Well-Known Member
Potassium silicate like, Silica Blast, Armor Si or powdered potassium silicate.
Ezylyfe
Active Member
Green cure as mentioned before also Lost Coast Plant Therapy works incredibly for PM and many other plant problems its better used as a preventive one a week for the duration of the plants life especially outdoor. Have a read on them I think they have free samples lots of great reviews etc etc got me to try it I'm convinced so far