Hemp's newfound status as a cash crop has inspired thousands of American farmers to seek cultivation licenses, and many among them are seeking ways to protect their crops from pests and fungus. While hemp is conveniently resistant to certain pests and disease, insects like cutworms and fungi like Sclerotinia sclerotiorum (white mold) still plague hemp farmers and threaten to destroy entire crops.
There are no pesticides registered by the Environmental Protection Agency (EPA) specifically for use on hemp. However, according to the National Law Review, there are six federally registered pesticides listing hemp among their labeled applications, meeting the notable criteria that none of those contain food tolerances for residue levels (the reason being that none were registered prior to passage of the 2018 Farm Bill), and thus deemed to be safe. As the National Law Review described, "an exemption from food tolerance requirements is critical for any company seeking to incorporate hemp or hemp-derivatives, like cannabidiol (CBD), into food or medicines."
Until very recently, hemp has typically been grown for things like fiber production. With the passage of the Farm Bill and popularity of CBD, most hemp cultivators started growing it for smokable flower or CBD extraction, subsequently raising safety concerns about human consumption.
Though the EPA has approved no pesticides specifically for hemp production, several states have. Colorado's agriculture department has approved hundreds of pesticides for both hemp and cannabis. Many of them contain ingredients called biopesticides, defined by the EPA as "pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals."
One of the most common biopesticides used in hemp and cannabis production is Azadirachtin. Derived from the seeds of the neem tree, Azadirachtin has a very low toxicity in mammals and starts to degrade within 100 hours of coming into contact with light or water.
The substance acts primarily as an antifeedant, an organic compound released by plants to attack insects. Azadirachtin also works as a growth disruptor, interfering with an insect's endocrine system.
Currently, the EPA is reviewing 10 applications from three different California-based companies for pesticides to be used for hemp production. Those companies include Agro Logistic Systems, Hawthorne Hydroponics, and Marrone Bio Innovations.
Each of the products under review have been approved for use on other crops, and contain active ingredients considered to be "tolerance-exempt" by the EPA, meaning that there is no amount of that active ingredient which is regarded as harmful to humans.
According to Carrie Link, Marrone Bio Innovations' senior regulatory manager for Regulatory and Government Affairs, the EPA purposefully chose products with tolerance-exempt active ingredients since they are easier to regulate than non-tolerance- exempt products.
"The EPA needs to decide first what all of the requirements for pesticides needs to be," Link said. "They're essentially going for the low-hanging fruit first because they can tell how it will fit into their regulatory framework."
Link added that while the process for adding a new crop on a pesticide's approved uses typically takes four months, it has taken much longer for Marrone Bio Innovations given the EPA's regulatory uncertainty. Nevertheless, Link expects the EPA to decide on all 10 applications before year's end.
Written By: William Sumner