HLVd-Tested Cannabis Clones

Hop Latent Viroid is a tiny infectious RNA that hijacks the plant without killing it. Infected plants often look normal through veg and only reveal the damage at harvest: 30–50% lower THC, smaller and looser buds ("dudding"), weaker terpene expression, brittle stems and stunted growth. It moves mechanically — on blades, on hands, in irrigation runoff — so one infected clone in a room becomes many by the time anyone notices. Because the damage is invisible for months, the only economic defense is to keep it out in the first place. More background: what is HLVd.

• The right test. RT-qPCR (quantitative reverse-transcription PCR) detects the viroid's RNA directly with sensitivity down to a few copies. Visual inspection cannot; a plant can be infected and asymptomatic for its whole life.
• Every mother, on a schedule. A single historical test proves nothing about today. Mothers live for months and are handled daily; they need to be re-tested on a recurring cycle.
• Quarantine before the library. New genetics are the main way viroid enters a nursery. They must be isolated and tested before a single cutting is taken.
• Sanitation that matches. Sterilized blades between plants, isolated propagation rooms, and no shared tools between quarantine and clean stock.
• Results you can see. A nursery that tests will show you recent results without hesitation.

• Quarantine and test all incoming genetics before they enter the mother room. Roughly 28% of incoming cuts test HLVd-positive — those are cleaned or rejected and never propagated.
• RT-qPCR every mother plant in the library on a recurring schedule, for both Hop Latent Viroid and Fusarium — several hundred tests a year.
• Cut only from mothers with a current clean result, in dedicated propagation rooms with sterilized tools.
• Publish the protocol. The full program and our by-the-numbers data are on the HLVd testing page.

We run this program because we are a nursery: the mother library is the business, and a viroid in it would end us before it hurt you.

1. Do you PCR-test every mother plant for HLVd — and how often?
2. Do you quarantine and test incoming genetics before propagating them?
3. Do you also screen for Fusarium and other pathogens?
4. Can I see a recent result?
5. What happens to a mother that tests positive?

If the answers are vague, the clones are untested no matter what the menu says. Our how to avoid HLVd guide walks through sourcing, quarantine and receiving in more depth.

Testing at the nursery is the first line of defense, not the last. Quarantine incoming plants away from your existing canopy, sterilize blades between plants during defoliation and cloning, avoid recirculating runoff between rooms, and consider periodic PCR screening of your own mothers if you keep any. Clean genetics in, clean practices inside — that is the whole game. See cannabis IPM and clone problems and troubleshooting.