Correct dosage for potassium bicarbonate fungicide

[Kobus Jooste]

Hi there

 

Can anyone familiar with potassium bicarb - based commercial fungicides please give me an indication of the following:

1) The % potassium bicarb in the product

2) The suggested application rate / mixing charts.

 

I cannot get the prepared mixes here in my town, and want to make my own mix starting with 100% food grade potassium bicarb.  I have been trying to research the topic but get widely ranging mix recommendations, mostly based on sodium bicarbonate. 

[David Hart]

Interesting link, thanks for sharing Glenn.

[Kobus Jooste]

Thanks for the info Glenn.  Just out of interest sake, is there also such an enormous gap between the price of chemist-sourced potassium bicarbonate and the commercial fungicides that use it as an active ingredient in other parts of the world?  Over here I can find it on the net, but the priice difference (commercial prep is overpriced) is amazing.

[TCLynx]

If there is a such thing as beer/wine making supply in your area, it might be an option for getting potassium bicarbonate.  At least that is where I've always heard to go looking for it.

 

I don't know anything about the price comparisons though.

[Kobus Jooste]

Hi TC - getting it through the pharmacy is relatively cheap and easy.  I have seen prices 600% more on our online sites.

TCLynx said:

If there is a such thing as beer/wine making supply in your area, it might be an option for getting potassium bicarbonate.  At least that is where I've always heard to go looking for it.

 

I don't know anything about the price comparisons though.

[TCLynx]

Let us know how you do with the above listed recipes then.

What particular fungus problems are you battling?

[Kobus Jooste]

I have fungal issues in the duckweed beds of all places, which makes treatment tricky.  Cannot use wetting agents because I don't want to coat the duckweed in oil.  I need to knock the fungus (spreading grey dead spots) out without messing anything else up.  I have been able to suppress with very light doses of sodium bicarb while I waited for the potassium bicarb.  It is winter thus the fungus is not that aggressive, but it has shown up once in the past during hot weather and it was devastating.

TCLynx said:

Let us know how you do with the above listed recipes then.

What particular fungus problems are you battling?

[TCLynx]

Well I know some fungus issues can be knocked out with the change of pH (I think this is particularly true of downy mildew.)  And then I've been told that powdery mildew tends to attack plants with potassium deficiency during particularly hot/dry but humid weather, I know sounds odd but it's the kind of weather we often get here in FL.  Hence I expect potassium bicarb will be a good choice to battle either one of those problems and hopefully much more.

 

Another possibility if you have access to some good worm castings might be to brew some activated worm tea and spray it diluted over the duckweed beds since it is supposed to be really good at combating all sorts of problems.