Everything growers need to know about regulations on products that combat powdery mildew, spider mites and other common pests and diseases
By Karli Petrovic
When battling the pests and diseases that damage and destroy cannabis crops, it’s important to be prepared. Of course, this is easier said than done. While growers who produce ornamental plants can often select any number of chemicals off the shelf at the local garden center, marijuana growers must be much more selective.
Legalities and Labeling Laws
Although unlikely to be a major storyline in a primetime crime drama, it is illegal to use certain pesticides on marijuana plants. In fact, Colorado Department of Agriculture spokeswoman Christi Lightcap says very few pesticides are approved for use on this crop.
“The label — the directions for use — that comes with each pesticide is a legal document, and any use inconsistent with the label directions is a violation of both Colorado law and federal law,” she explains. Lightcap notes that marijuana is not listed as a use on any pesticide labels, a situation that may remain unchanged for some time.
The U.S. Environmental Protection Agency is “unlikely to allow marijuana on a label until the federal status of marijuana as a Schedule I drug is changed,” she says. “This means that only products with very broad language on the label can be used on marijuana.”
A phrase like “for use on any crop” is one example of broad label language. Of the hundreds of thousands of pesticide products available on the market, the Colorado Department of Agriculture has identified a mere 250 that can be used on marijuana. The department hopes to have determined and implemented rules classifying the standards for pesticide use on cannabis by spring of 2016.
While Lightcap says these rules might further restrict the chemicals that can be used, there’s a possibility that certain EPA-registered pesticides may be registered for “special local needs (SLN).”
“We have been working closely with EPA to figure out how SLN registrations can be approved by Colorado with label directions specific for use on marijuana and hemp,” says Lightcap.
“In some cases, research studies may be needed of the pesticide residues left on marijuana before we can complete a human health risk assessment and make an SLN decision.”
Although Colorado has led the charge on determining what crop protection products are appropriate for marijuana plants, Washington and Oregon are following suit. Voters legalized medical marijuana in the Washington in 1998. However, it wasn’t until recreational marijuana was legalized in 2012 that people started questioning what pesticides were being used on the crops, says Erik W. Johansen, the Washington State Department of Agriculture’s pesticide expert.
“At that point, we started working with the EPA and the Colorado Department of Agriculture to try and figure out what types of products were allowed for use on marijuana,” Johansen explains, noting that the criteria was finalized in 2013. “Our first list contained 150 pesticides. Now we’re up to a little more than 300 pesticides in late 2015. We’ve reviewed more labels and are working with the EPA and CDA on a process for allowing additional pesticides on the list.”
While more than 300 options may seem adequate, Johansen says the pesticides contain only 70 to 80 active ingredients, meaning there are a lot of different brand names for essentially the same product. For example, there are about 20 products containing indole-3-butyric acid (IBA).
Of the allowed products, pesticides usually fall into one of two categories: biopesticides (which are derived from natural sources such as microbes, bacteria or plant extracts) and organic pesticides.
Synthetic pesticides are not an option, because marijuana is smoked or consumed, thereby classifying it as a food crop.
This is good for consumers, but synthetic pesticide formulas tend to be more effective against tough-to-tackle pests and diseases.
“What we’ve heard from growers over the past two years is that the products for spider mites and powdery mildew are not necessarily what they need,” Johansen says. “That’s why we are getting guidance on a mechanism for getting additional products to growers.”
Consumer trends
As the states continue to crack down on what pesticides can be used on marijuana plants, crop protection manufacturers who want to compete in the marketplace must create products that account for the tighter restrictions.
“I think everyone, even those in the horticultural world, has a standard they are trying to achieve,” says Jeff Kline, product manager for BioSafe Systems. “A lot of it is driven by the consumer being more aware of what’s being put on their food and flowers. The same thing goes for the cannabis industry.”
Susan E. Lewis, founder and president of Pharm Solutions, notes a similar trend.
“Consumers are more aware these days of organic and pesticide-free products and seek them out,” she says. “We believe this is the future for cannabis growers as well. Given the choice, the consumer will choose organic over products sprayed with synthetic chemicals.”
One person who can attest to this is John Sladek. A cannabis grower for more than 40 years, Sladek originally learned to grow medicinal marijuana on the fly when his wife was diagnosed with cancer in the 1970s. After her death, Sladek continued growing marijuana using organic products for others in need.
While growers currently have a variety of pesticide options, changing regulations are sure to impact the number of products on the market. The onus is on individual states to ensure product safety. Kline sees that as a positive.
“The states have done a good job of paying attention, learning and changing what’s going on the crops to make sure people aren’t negatively impacted,” he says. “It will be interesting to see how things go forward from a regulatory perspective.”
The Learning Curve
As pesticide regulations continue to be in flux, each state is recognizing that education and outreach will be essential to ensure safe application of legal products. Johansen, for example, is traveling across Washington to meet with marijuana growers, the Washington Marijuana Business Alliance and private consultants to talk about proper pesticide use.
He says everybody involved recognizes the need for disseminating accurate information.
“That’s why we’re providing outreach to the industry and telling them what they can use and, more importantly, what they can’t,” he says. “We also want to talk to them about what they can do to get more products added to the list.”
In Colorado, Lightcap says the state Department of Agriculture is providing growers with seminars and assistance related to pesticide use. Although the regulations can be a hassle, safety needs to be a top concern, she says.
“I know that, as with any agricultural grower, they are selecting products based on effectiveness on the pest of concern, safety to the crop, cost and ease of use. However, they should also read the label fully and carefully prior to purchasing the product, to make sure they can legally use it in the way they intend,” Lightcap says.
“The cannabis industry has an ethical and legal obligation to only use products that are legal to use and currently meet the CDA’s criteria for use.”