# Hop latent viroid

> HLVd, a small infectious RNA that spreads through sap and tools, causing stunting, brittle stems, small loose buds and reduced resin in cannabis; called dudding.

- Canonical: https://genetixbay.com/knowledge/glossary/hop-latent-viroid.html
- Also written: HLVd, hop latent viroid disease, dudding, dudding disease, duds, dudded plants
- Glossary category: Pests and diseases · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Hop latent viroid (HLVd) is a [viroid](https://genetixbay.com/knowledge/glossary/viroid.md), a tiny circular RNA of about 256 nucleotides with no protein coat, that infects hops and cannabis. In cannabis it causes "dudding": plants that grow slowly, with shorter [internodes](https://genetixbay.com/knowledge/glossary/internode.md), brittle stems, smaller and looser flowers, and less resin. Many infected plants show few or no symptoms for long periods, especially [mothers](https://genetixbay.com/knowledge/glossary/mother-plant.md) in veg, which is how it spreads unnoticed.

## In practice

HLVd moves in sap: on scissors, razors, hands and clones taken from infected mothers. It is also found in roots and [recirculating](https://genetixbay.com/knowledge/glossary/recirculating-system.md) solution, and seed transmission has been reported at low rates. Detection needs a lab test, typically RT-qPCR on root or leaf tissue. There is no cure for an infected plant. Clean-up relies on testing mothers, discarding positives, sterilising tools between plants, and recovering clean stock by [meristem tip culture](https://genetixbay.com/knowledge/glossary/meristem-culture.md).

## Myth check

"[Clone decline](https://genetixbay.com/knowledge/glossary/genetic-drift.md)" or "genetic drift" in old cuts is a pathogen story, not a genetics story. GenetixBay's house position is that there is zero genetic drift in kept cuts apart from pathogens such as HLVd; the founder keeps cuts more than 40 years old with no decline. Label: Supported. See [HLVd and viruses](https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md) and [Mythbusters](https://genetixbay.com/knowledge/mythbusters.md).

## Don't confuse with

- **Nutrient lockout**: responds to root-zone fixes; HLVd does not.
- **Hermaphrodite traits**: genetic; HLVd is infectious.

## Related terms

[Viroid](https://genetixbay.com/knowledge/glossary/viroid.md), [Plant virus](https://genetixbay.com/knowledge/glossary/plant-virus.md), [Sanitation](https://genetixbay.com/knowledge/glossary/sanitation.md), [Quarantine](https://genetixbay.com/knowledge/glossary/quarantine.md), [Biological control](https://genetixbay.com/knowledge/glossary/biological-control.md)

## Read more

- [Hop latent viroid (HLVd, 'dudding') and other cannabis viruses](https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md)

## Sources

1. Adkar-Purushothama CR, Sano T, Perreault J-P, 2023. Hop latent viroid: a hidden threat to the cannabis industry. Viruses 15(3):681. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10053334/
2. Punja ZK et al., 2025. Hop latent viroid transmission, spread and longevity in cannabis; meristem tip culture. Plants 14(5):830. https://www.mdpi.com/2223-7747/14/5/830
3. Oregon State University Extension. Hop latent viroid in hemp (EM 9570). https://extension.oregonstate.edu/catalog/em-9570-hop-latent-viroid-hemp