Tank mixing and pesticide compatibility - "The jar test"
Are you considering a new tank mix this year? Perhaps two new fungicides, or an adjuvant you want to try? Be sure you know what you're doing before you risk an untested tank mix. Users of commercial class pest control products for crop protection or vegetation management are permitted to apply unlabelled tank mixes of registered pest control products as long as:
The order in which you add each product to the tank or inductor is critical. Making sure you have the right mix, in the right order, is made easier with the free app from Precision Laboratories (www.mixtankapp.com) which works on Android and iPhone/iPad systems.
At the start-up screen, select "Mix Guide" (see Figure 1). Then, select the category of the product you wish to tank mix (see Figure 2) and then select the product(s) from the alphabetized list. The app analyzes your selections and suggests the best order to add them to the tank. Note that these are US products, which means they may have different names in Canada, if they are registered at all. The app has other appealing features you can explore, such as saving your mixes for future reference, and accessing instructional videos.
Figure 1 - Precision Laboratories' Tank Mixing App Start-Up Screen
Figure 2 - Select from five categories and choose up to 19 tank mix partners
Always check the product labels for information on compatibility of spray materials. "Compatibility" refers to the physical and/or chemical compatibility of two or more products in a solution. If you are concerned, you should perform a jar test. Always wear personal protective equipment and do it in a safe and ventilated area, away from sources of ignition.
Figure 3 - Physical incompatibility in the tank
Figure 4 - Gelatinous mess made by using an inductor as a mixing vat for incompatible products
Commercial compatibility kits are available, such as the kit from Precision Laboratories. This kit contains three plastic "jars" and five disposable micropipettes (see Figure 5). By following the instructions included with the kit, you can easily reduce large labelled volumes (such as 1.0 kilogram of product in 500.0 litres) of multiple products to small volumes at the same ratio. These kits can be purchased for ~$20.00 (including delivery) by calling 1-800-323-6280.
Figure 5 - Contents of a commercially-available compatibility test kit
Remember: a compatibility test will only reveal physical incompatibility between products in a tank mix - they will not reveal any other form of antagonism, such as products inactivating one another, or the potential for phytotoxicity. The only way to know for sure is to apply the mix to a few test plants and keep an eye on them over the season.
For more information:
Toll Free: 1-877-424-1300