sodium bicarbonate

[Eric02476]

Originally Posted by Bipetual

Green Cure, which is the potassium bicarbonate, says on the label not to store unused solution, so I suspect it does not keep.

It does keep. Just yesterday I received an email from GreenCure (a very friendly and knowledgeable gentleman named Pete) in response to some product use questions I submitted via their website, and he mentioned this as an aside:

"By the way, if you mix more GreenCure than you use you can keep the mix in a well-marked container. The wording on the label about not storing the mix is there because the EPA requires that language on any mix it yourself product."

Makes me wonder how many other products actually can be stored....

Eric

[Eric02476]

Originally Posted by Itoero

ok,

But with potassium bicarbonate I should have better results?
Is there any known difference between potassium and sodium bicarbonate as fungicide?

Yes. There is a good body of scientific research supporting greater efficacy of potassium bicarbonate vs. sodium bicarbonate as a horticultural fungicide. The information is commonly published by reputable academic extension agencies, such as in this PDF link:

https://www.extension.purdue.edu/ext...bp/bp-69-w.pdf

As others have mentioned, neither bicarbonate is effective unless mixed with a surfactant (spreader sticker). I'm currently using GreenCure, a commercially premixed potassium bicarbonate product, for the sake of convenience.

[jmsieglaff]

Whipped up a batch tonight and treated my cucubrits which were just starting to get powdery mildew. I was amazed that it seems to work instantly. The leaves that I treated first that had some signs no longer did. I was careful to get tops and bottoms of the leaves. I also treated some flox that always get PM. I'm curious to how things will look tomorrow and in the coming days. Thanks again Ray!

[ilex]

I burned my plants once with sodium bicarbonate, so be very careful. I would use potassium bicarbonate.

[jmsieglaff]

Originally Posted by ilex

I burned my plants once with sodium bicarbonate, so be very careful. I would use potassium bicarbonate.

I used Rays recipe. 4 tsp potassium bicarbonate, 1 tsp neem and 1 tsp dish soap to 1 gallon of water. The treatment worked well. I will likely reapply this weekend.

[RayR]

Originally Posted by jmsieglaff

I used Rays recipe. 4 tsp potassium bicarbonate, 1 tsp neem and 1 tsp dish soap to 1 gallon of water. The treatment worked well. I will likely reapply this weekend.

Is that what you used? Because my recipe was 4 tsp. potassium bicarbonate / 1oz (2 Tablespoons) Neem Oil / 2 tsp. Dish Soap.

[jmsieglaff]

Sorry it was 1 oz Neem, but I did do 1 tsp dish soap. I'll bump up to 2.

[RayR]

Originally Posted by jmsieglaff

Sorry it was 1 oz Neem, but I did do 1 tsp dish soap. I'll bump up to 2.

PM showed up on my squash this week so tonight I mixed up a gallon and sprayed away.
I checked the PH of the mix and it was a little over 8.5 which is where you want it too be. PM spores can't tolerate a leaf surface with a high PH.

[Nathalie]

I just did this today when my seedlings (2 months old) showed signs of PM, and sprayed them with the same recipe above (Ray's) but omitting the oil as I didn't have it at home...

But now the leaves are wilting and look rather sad (no discolouration, just looks very sloppy). Was this too strong for seedlings, only aimed for mature plants?

[Nathalie]

By the way - it was Sodium bicarbonate, and I saw that 'Ilex' said to be careful as it burned the plants.. maybe that was why this happened, despite I followed the recipe?

Only the bigger lower leaves are wilting, the younger ones in the growing zone are OK.

[TC_Manhattan]

Originally Posted by Nathalie

By the way - it was Sodium bicarbonate, and I saw that 'Ilex' said to be careful as it burned the plants.. maybe that was why this happened, despite I followed the recipe?

Only the bigger lower leaves are wilting, the younger ones in the growing zone are OK.

You can buy potassium bicarbonate on eBay. I have a 1# bag I got end of last season.
I think they use it somehow in winemaking.

[Nathalie]

Thanks, I did buy it from Germany through Amazon.de yesterday, 2 lbs bottle. Couldn't find it anywhere in Sweden, only sodium bicarbonate, so that was why I tried that first.

Hope it will be less shocking for the plants!

But I can't see the PM anymore on the stems, which is wonderful! But the bigger leaves wilted away and had to be discarded, the younger leaves are OK, so the plants look line amputated seedlings now, ha.... so I look forward to the potassium bicarbonate to avoid that side effect

[jmsieglaff]

Originally Posted by RayR

PM showed up on my squash this week so tonight I mixed up a gallon and sprayed away.
I checked the PH of the mix and it was a little over 8.5 which is where you want it too be. PM spores can't tolerate a leaf surface with a high PH.

Has anyone tried this as potential treatment of Septoria on tomatoes? A shot in the dark, but maybe the Septoria spores also don't like that PH?

[RayR]

Originally Posted by jmsieglaff

Has anyone tried this as potential treatment of Septoria on tomatoes? A shot in the dark, but maybe the Septoria spores also don't like that PH?

It's been done before and it's not effective against Septoria.
Septoria and Powdery Mildew are very different species of fungi.

[jmsieglaff]

Originally Posted by RayR

It's been done before and it's not effective against Septoria.
Septoria and Powdery Mildew are very different species of fungi.

Good to know. Figured this was the case, but you never know.

More heavy rain here tonight--I think the 3 some inches on Sunday night washed off the plants clean 10 times over.

Copper spray tomorrow evening or Thursday evening, depending if we still have the shot at storms tomorrow evening or if the front as passed us by.