This article is featured with permission from Growers’ Network. In this Growers Spotlight, they interviewed Erik Johansen, who works for the Washington State Department of Agriculture (WSDA) as a policy assistant largely dealing with cannabis-related topics involving pesticides.
What’s the definition of a pesticide?
A pesticide is a chemical or biological preparation that is designed to control, repel, and/or mitigate a pest. Pesticides are usually defined by the type of pest they control and their mechanism of action.
A pest can include:
- Any animal that can harm a plant, including insects, birds, mammals, and more.
- Plant pathogens, viruses, or their transmission vectors
- Undesired weeds or competing plants
- Harmful microbes.
Pesticides are regulated at the federal level by the Environmental Protection Agency (EPA). The EPA establishes “tolerances” for pesticides, which are the legal limit of residues of pesticide that can remain on a crop at the time of harvest. The problem for commercial cannabis growers is that cannabis is not recognized by the federal government as a legitimate crop. For this reason, the EPA does not set a pesticide tolerance for cannabis; because there is no legally established tolerance for cannabis, pesticides that must be registered with the EPA are not eligible for use of cannabis in states that have legal cannabis.
However, there are exceptions to EPA pesticide registration, and these are most commonly known as section 25b minimal risk pesticides. These pesticides are described as “minimal risk” because their active ingredients have been used for many years with no signs of side effects or toxicity. For example, the essential oils are described as minimal risk pesticides because over their many years of use, there has been little to no evidence that the essential oils are dangerous for humans to consume.
The WSDA considers minimal risk pesticides to be “permitted” for use on cannabis, and as such, allows companies to register products with these pesticides for use on cannabis.
Cannabis in Washington
Cannabis grown in Washington has the same pests it does elsewhere in the country. That means that growers in Washington have to worry about spider mites, mildew, mold, thrips, aphids, and a few other mites. While the WSDA does not make recommendations of any particular products, Erik does sympathize with growers. If you’re growing a major crop like potatoes, you have somewhere between 1200 and 1500 pesticides to choose from. With cannabis, however, you’re restricted to about 340.
What this means for growers in Washington is that Integrated Pest Management is an absolutely critical method to growing. If you’re not practicing IPM in Washington, you’re gambling with your product. Erik strongly encourages actively monitoring your grow operation. In his words, “Monitor. Monitor. Monitor.”
And while there’s legally no such thing as organic cannabis, any growers who want to grow “organically” must take even more steps to ensure that their grow is pest-free.
Protecting Yourself and Your Crops
Minimal risk pesticides, owing to their nature, only have some pesticidal activity. They have value, to be certain, but controlling all the pests with just minimal risk pesticides is a dangerous proposition. Because integrated pest management requires more time and effort, some growers will be tempted to use other tools to control pests. These include pesticides intended for home personal use (not commercial use) and foliar/leaf shines which have pesticidal activity.
But be warned — using home use pesticides not approved for use on commercial cannabis in a commercial grow operation can land you in trouble. And foliar/leaf shines are generally intended for plants that are considered ornamentals, not plants that are meant to be consumed like cannabis.
If you don’t understand what the laws, rules, and exceptions are, you need to talk to somebody that does. It’s going to be someone in the state lead agency in whatever state you’re working.