New PMRA policy proposal takes aim at tank mixes

The Pest Management Regulatory Agency is proposing a new policy on tank mixing crop protection products. If the policy is adopted, any tank mix not on the product label would be considered an off-label use.

While many tank mixes are listed on product labels, many others have been adopted over time without the expensive bother of official registration. If the products are compatible in the sprayer tank, if the tank mix doesn’t cause crop injury and if the products are still effective, why not combine them?

Making one trip across the field with a tank mix is a lot more efficient and environmentally friendly than making two or three trips with separate products.

As producers, most of us don’t pay attention to whether the tank mixes we’re using comply with label registrations. We just get advice from the herbicide companies and the agrologists and agronomists from input supply companies on what can be mixed and what mixes to avoid. There are also rules for adding ingredients in the proper order.

Here’s an example of a tank mix some producers are using that’s not actually on either product label. Avadex, with the active ingredient triallate, has been around for decades. In fact, it’s a product that pre-dates the use of glyphosate.

Avadex is for pre-emergent wild oat control and it’s available as a granular and liquid product. The use of Avadex is growing despite it being an old chemistry because it provides a different mode of action for wild oat control, an important tool for fighting herbicide resistance.

Some producers like to mix liquid Avadex with glyphosate in a pre-seeding application. The glyphosate kills emerged weeds. The Avadex is for control of wild oats before they emerge. The mix causes no harm, but it’s never been officially registered and put onto the product labels.

If the new policy proposed by the PMRA is adopted, this sort of off-label use will be technically illegal.

According to the Canada Grains Council, which represents all facets of the grain industry, this would be a reversal of PMRA’s long-standing guidance authorizing the use of tank mixes that do not have specific labels.

It would also be a departure from how the United States Environmental Protection Agency handles the issue.

The federal government says it wants to reduce the regulatory burden on businesses and the PMRA is already overwhelmed with its ongoing safety reviews of products. And the change would put Canadian farmers at a disadvantage to their American counterparts. It just makes no sense.

You might think the change won’t have any tangible effect at the farm level. Producers might just continue to use the same tank mixes they always have.

However, producers are being routinely required to declare to buyers that they have applied products according to label recommendations. If the PMRA makes this change, tank mixes not explicitly allowed on product labels will make a grower offside in these declarations.

According to the Canada Grains Council, there’s uncertainty on the transition time to the proposed policy with the PMRA indicating the change might immediately be implemented. With that approach, there would be no time for the industry to adapt.

Adding a regulation that doesn’t improve safety, increases costs and increases the environmental footprint of crop production is nothing short of ludicrous. Member organizations of the Canada Grains Council are expressing their concerns. Hopefully, some common sense will prevail at the PMRA.

Kevin Hursh is an agricultural journalist, consultant and farmer. He can be reached by e-mail at

About the author


Stories from our other publications