Report: More Than 90% of California Cannabis Infected with Hop Latent Viroid

More than 90% of cannabis in California is infected with a pathogen that effectively destroys the plant and could wreak havoc on the state’s industry, according to an SF Gate report. Hop-latent viroid (HLVd) shrivels cannabis plants, reducing how much weight they produce by as much as 30%, and cutting THC in the plant by as much as half, the report says.

The pathogen was first documented in cannabis in 2019 and it is estimated to have infected most of the state’s cannabis. In 2021, Dark Heart Nursery announced the results of a formal survey that found, after 200,000 tissue tests, 90% of California facilities included in the research had HLVd, according to a Cannabis Business Times report.

The pathogen has also been found at cannabis grows in Massachusetts, according to an NPR report from February.

Tests have been developed to determine whether a plant is infected with the pathogen — one by Oakland’s Purple City Labs can be conducted on-site and delivers results in just a few hours.

If a plant is infected by HLVd, it must be destroyed, Nick Masso of Massachusetts-based Indo Labis told NPR.

“You cannot recover from hop latent viroid,” he said.

The pathogen spreads quickly because cultivators often use cuttings from a mother plant to propagate more plants, but the new plants are already infected, and the viroid spreads exponentially.