Many manufacturers provide information on the rate at which their products hydrolyze. This rate is usually expressed as 'half-life' or the 'time it takes for 50% hydrolysis or breakdown to occur'. With trichlorfon or DYLOX, for example, the time for 50% hydrolysis at pH 8.0 is but 63 minutes; at pH 7.0 50 % breakdown occurs in 386 minutes. and at pH 6, 80 hours.
This means that if the pH of your spray water is 8 and one hour elapses between the time you add the insecticide to your spray tank and the spray dries on the foliage, 50% of the active ingredient has already decomposed. But if your water has a pH of 6, it is not likely that you will lose any significant activity during the process of application.
any application of pesticides one should ph it between 4 -6 range
There are a few pesticide materials which should not be acidified under any circumstances. Sprays containing fixed copper fungicides (including Bordeaux mixture, copper oxide, basic copper sulfate, copper hydroxide, etc.) and lime or lime sulfur should not be acidified. But, if the product label tells you to avoid alkaline materials, chances are good that the spray mixture will benefit by adjusting the pH to 6 or slightly lower.
The major benefit from acidification is obtained during the time the pesticide is in the spray tank; that is, from the time the pesticide is added to the water in the tank to the time the spray has dried on the foliage. If your water source is alkaline, addition of a buffering agent to the spray preparation is an easy and economical way to guarantee maximum results from your pesticide applications.
Its amazing how fast it happens or what 1 point of ph does for instance
Dy-lox or common name Triclorfon 50 percent hydrolosis with ph @ 8 will happen in 6.3 mins from the time you added water
same product @ 7 ph 6.4 hrs @ 6 ph 3.5 days before it reaches 50 percent hydrolosis or half life