I know over on GW this was talked about some (phosmet i think was the pesticide that was brought up most of the time). My well water is hard and the pH i would imagine is high (haven’t tested) and i use it to mostly mix pyrethrin. On this chart I don’t see that listed, but as you can see…high pH drastically reduces the effectiveness of most (all?) pesticides over time…So what does a guy/girl do? Should I be buying distilled water adding something to reduce pH?? I usually can’t spray everything on the same day…the cots always come first and so on. On the other hand…if you need to get rid of pesticide, i would imagine this would be a good way to degrade it (add some lime?).
I think the Phosmet literature actually gives you a dosage of white vinegar to lower ph…when I get a chance, I’ll look into that. I either read it on the literature or somewhere online.
Why citric acid Olpea instead of just vinegar that everyone has? Just curious, is citric acid better for some reason? Where do you get it?
I do wonder about the vinegar since in concentrated form it functions pretty well as a herbicide. Maybe citric acid would as well?
Warm…thanks for posting this. I was aware that lowering ph increased effectiveness of many insecticides and fungicides, but I had NO IDEA it was this much.
I thought the improvement was just a minor thing, this is incredible!
I suppose just about any organic acid would work to safely lower pH, and probably even some inorganic acids. I use citric because it’s cheap, cheaper than vinegar. One can buy 50 lb. bags of food grade citric acid fairly inexpensively, which will treat thousands and thousands of gallons of water.
Mike,
My water runs around 9.4 pH with a range somewhere between 9.1 - 9.5. Several years ago I experimented with different amounts of citric acid to see how much is required to lower the water to different pH levels. I used a tester which I checked against known pH values. Little pH test packets are available the varying pH levels (pH 7, pH 4, pH 9, etc.) I teaspoon per 25 gallons lowers my water 7. Without looking it up, I think 1 teaspoon per 16 gallons lowers the pH to 6.4.
I just came across some articles that opened my eyes to the huge effect ph has on pesticides. it looks like the target range is 5 to 5.5. Any idea where I can buy a buffer?
You can get 50 lb sacks of citric acid from Midwest Grower Supply. They’ve recently changed their name to something, but I think you can still google them and come up with a phone number. You may be able to get it at East Kansas Chemical in Wellsville (I think they changed their name to Performance Ag). I don’t think you are too far from there.
Thanks. I am still trying to understand the correlation between pH and pesticides. Will it matter once it is dry and on the tree? I will try acids but a buffer might be simpler becuase i work with differnt water sources at a couple sites.
My understanding is that once it’s dry it’s no longer subject to alkaline hydrolysis. I believe I’ve read that somewhere.
I’m not a chemist for sure, but I think for alkaline hydrolysis to occur, the molecules must have a certain freedom of movement to react the the -OH ions of alkaline water. Once the spray dries on the leaves/fruit, interaction w/ the ions stop. Rain will re-wet the foliage, but most rain is slightly acidic which would help prevent hydrolysis I think. I’m not sure how dew would play into the whole thing.
Yeah…rainwater is pretty good 5 - 5.5, but if it’s captured in a concrete cistern it starts going the wrong way again they say. Captured rainwater stored above ground can contain some bad guys though.
