Hop-latent viroid, or HLVd, shrivels pot plants and reduce how much weight they produce by as much as 30%. It also destroys the amount of THC, pot’s most common active compound, that a plant produces, greatly reducing the value of affected plants.
It’s now infected at least 90% of California’s cannabis grows, according to a 2021 estimate. It’s spreading globally
FWIW, a Reddit discussion