April 15, 2010
By Denise Beaton
OMAFRA crop protection lead

There are a few benefits to tank mixing pest control products, such as saving time and fuel by making fewer trips over the crop with the sprayer. It could also result in managing more pests. Also, tank mixing may be a good resistance management or integrated pest management strategy.

Many pest control product labels have directions for tank mixing two or more products together. These labelled tank mixes were reviewed by the Pest Management Regulatory Agency (PMRA) and determined as acceptable and to have value.

But what about unlabelled tank mixes? Some growers want to apply tank mixes that do not appear on the product labels. Previously, it wasn’t clear whether growers were allowed to apply these unlabelled tank mixes. In October 2009, the PMRA provided clarification on its position regarding the use of unlabelled tank mixes of commercial class pest control products used for crop production and vegetation management. According to the PMRA, growers can apply unlabelled tank mixes, subject to the following conditions:  
  1. Each tank mix partner is registered for use in Canada on the crop being sprayed, including genetically modified crops.
  2. Use an adjuvant only when required by one of the tank mix partner labels.
  3. The application timings of all tank mix partners are compatible with regards to crop and pest staging.
  4. Follow the directions on the label (for example, directions for use, precautions, buffer zones, etc.). In cases where information on the tank mix partner labels differs between them, the most restrictive directions must be followed.
  5. Do not mix products if one of the tank mix partner’s label says you should not mix these products together.
  6. The use of the tank mix provides additional value to the user (example, increased scope of pests controlled, contributes to resistance management or integrated pest management, cost- or time-savings).
Be aware that any person who recommends, or applies an unlabelled tank mix is responsible for what happens. They are doing this at their own risk and are liable, since this tank mix has not been reviewed by PMRA. Some negative results that could result from using unlabelled tank mixes are reduced control of the targeted pest(s) and crop injury.

Ensure that tank mix partners are compatible (mix well together). Do not use products together if you see separation, coagulation, gelling or curdling when they are mixed.

You may direct any questions on unlabelled tank mixes of commercial class pest control products used in agriculture to the PMRA’s Pest Management Information Service. By phone, 1-800-267-6315, or email, pmra_infoserv@hc-sc.gc.ca.