I have been reading more on fungicide sprays. I came across this -
“Check the pH of the spray solution, especially when using alkaline well water. While most fungicides are stable over a range of pH values, some fungicides (e.g., Captan, Dithane, Rovral) can degrade under alkaline conditions. For example, the half-life of Captan is 32 hours at pH 5, eight hours at pH 7, and 10 minutes at pH 8. The half-life of Dithane is 32 hours at pH 5, 17 hours at pH 7, and 34 hours at pH 9. (Insecticides in general are more sensitive to pH than fungicides.) For a list of pesticides and their sensitivity to pH, see the 2012 Michigan Fruit Management Guide, pages 59-60. The pH can be adjusted with an acidifying or buffering agent. Avoid letting the spray sit overnight in the spray tank. Fungicides should, whenever possible, be mixed and sprayed as soon after mixing as possible.”
I think someone had mentioned (maybe Olpea or Alan) in the forums of the need for the water to be at the right PH level,.
I am using well water so I assume my PH will be around 7. I will get some PH test strips to confirm, What are common acidifying or buffering agents used with Captan/Water? My first thought is to use vinegar to lower PH but I do not know the pros/cons (hurt trees, sprayers)? Maybe the chemicals used to lower PH for pools? I assume PH of 5 is optimal with Captan from this article.
I see plenty of articles mentioning is Captan and Topsin M combined to together but I never see Topsin combined with
Myclobutanil. Is there a reason for why Topsin M should not be combined with Myclobutanil?