If there’s one thing we can count on, it’s receiving a question about tank partners at least once a week. Quite often, the question is about adjuvants. There are so many out there and each of them claims to improve pesticide performance substantially. How do you know which, if any, to use?
Adjuvants do everything from masking pesticide odor, to de-foaming spray mixes to conditioning carrier water pH. Let’s look at a couple intended to improve spray coverage and efficacy.
Spreader/Surfactant penetrating wax paper to get to water-sensitive paper.Surfactants (or wetter-spreaders) reduce the surface tension of the spray droplet, increasing the amount of contact between spray and target. They may also have penetrant properties to increase how well they permeate a leaf surface. If spraying a vertical target, they also increase the run-off effect.
Stickers help spray adhere to the target. They resist run-off and rain and are therefore great for waxy and vertical targets. Let’s see how many sprays it takes to cause run-off with a sticker.
There are also “Spreader-stickers” might sound like an oxymoron, but they’re generally a spreader with a fatty acid to allow them to spread on the target, but not run off as readily.
Some pesticide labels note a specific requirement for adjuvants to be tank mixed. You need to add these to the mix for the pesticide to work as advertised. They don’t come in the formulated product because of product stability, reducing bulk and of course, expense.
If you want to try an adjuvant, ask the product dealer about safe tank mixes. You don’t want to create physical incompatibilities in the tank or you might accidently make Jell-O. A jar test will tell you more about that. Perhaps worse, chemical incompatibilities reduce product efficacy or result in phytotoxiciity and burn your crop.
Special thanks to OMAFRA summer student, Victoria, for helping plan and film this video. Give her a follow @v_radauskas .