ASMA KHALID, HOST:
Cannabis growers are scrambling to ward off a highly infectious crop disease that's spread from California to Massachusetts. Tori Bedford from member station GBH reports on the threat to the nation's weed supply.
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TORI BEDFORD, BYLINE: The first step is to zip yourself into a marshmallow suit - white, full-body protective coveralls and booties. Pass through a portal of sanitizing mist and pressurized air, and you're safe to enter the propagation room at RiverRun Gardens, a small marijuana-growing facility north of Boston. It's a sort of high-security kindergarten for cannabis, where root cuttings called clones are grown from a mother plant.
ED DESOUSA: We are safeguarding these clones from contact with any type of virus that may be lingering.
BEDFORD: That's grower Ed DeSousa, and the virus he's referring to is called hop latent viroid, a plant-specific pathogenic RNA that's been called the greatest threat to the cannabis industry across the country. It can easily spread undetected, suck the potency out of plants and destroy the commercial value of crops.
Nick Masso of Indo Labs, a cannabis testing facility outside Boston, says by the time growers notice the signs, they have just one option.
NICK MASSO: Destroy everything. You cannot recover from hop latent viroid.
BEDFORD: Almost all of California's marijuana nurseries were affected in 2021, according to a survey from cannabis genetics company Dark Heart Industries. It's now an issue coast to coast. On a federal level, cannabis remains illegal, and shipping plants across state lines is prohibited. A gray area in some state regulations allows growers to acquire seeds or immature plants from out of state. Masso says that's a big factor in how the pathogens spread.
MASSO: It's a little more time-consuming to germinate from seed when you can start from a clone. And time is money.
BEDFORD: Hop latent viroid is preventable through rigorous sanitation, regular lab testing and sourcing plants from pre-tested seed or local stock. Companies that cut corners to save time and money, Masso says, are now facing the consequences.
MASSO: If they should happen to get hop latent viroid, I think that it is poetic justice.
BEDFORD: There's no known health effect on humans. Dr. Peter Grinspoon, a medical cannabis specialist at Massachusetts General Hospital, says the blight is more of a threat to marijuana businesses in an already fragile market, as demand has dropped and competition has increased.
PETER GRINSPOON: They need a viroid damaging the crop like they need a hole in the head.
BEDFORD: The blight is also emphasizing the importance of scientific testing. In Massachusetts, the state's regulatory agency, the Cannabis Control Commission, is just catching up. Commissioner Bruce Stebbins says they're building out testing and lab staff to ensure the procedures are actually compliant with regulations.
BRUCE STEBBINS: This is still a brand-new industry and there needs to be a lot more research done on the safety of the industry.
BEDFORD: When marijuana producers don't test properly, there's more of a risk of contaminated products, which could hurt consumers. Hop latent viroid comes with a financial consequence, which Masso says might force the industry to adopt higher standards.
MASSO: It'll be very interesting to see where this industry is in a year.
BEDFORD: As more companies and products enter the commercial cannabis market, the threat of disease puts pressure on businesses to think of safety before the bottom line.
For NPR News, I'm Tori Bedford in Boston. Transcript provided by NPR, Copyright NPR.
