# Plant virus

> An infectious particle of nucleic acid in a protein coat that replicates inside plant cells; on cannabis, often insect-spread and incurable once infected.

- Canonical: https://genetixbay.com/knowledge/glossary/plant-virus.html
- Also written: plant viruses, virus, viral disease, mosaic virus, tobacco mosaic virus, TMV, alfalfa mosaic virus, lettuce chlorosis virus
- Glossary category: Pests and diseases · Evidence: Supported
- 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"

A plant virus is a submicroscopic pathogen made of RNA or DNA in a protein coat, which can only multiply inside living plant cells. Viruses reported on cannabis and [hemp](https://genetixbay.com/knowledge/glossary/hemp.md) include [beet curly top virus](https://genetixbay.com/knowledge/glossary/beet-curly-top-virus.md) (spread by [leafhoppers](https://genetixbay.com/knowledge/glossary/leafhopper.md)), lettuce chlorosis virus (spread by *Bemisia* [whiteflies](https://genetixbay.com/knowledge/glossary/whitefly.md)), alfalfa mosaic virus and cucumber mosaic virus (spread by [aphids](https://genetixbay.com/knowledge/glossary/aphid.md)), among others. Symptoms include mottling, mosaic patterns, leaf curl, yellowing and stunting.

## In practice

There is no cure for a virus-infected plant. Management is [prevention](https://genetixbay.com/knowledge/glossary/cultural-control.md): clean propagation material, controlling the insect vectors, removing weeds that host viruses, and roguing infected plants early. Diagnosis needs a lab test such as ELISA or PCR, because symptoms overlap heavily with nutrient problems, genetic leaf variegation and [viroid](https://genetixbay.com/knowledge/glossary/viroid.md) infection.

## Myth check

Tobacco mosaic virus (TMV) gets blamed for nearly any mottled cannabis leaf, and smokers' hands are often named as the source. TMV can infect cannabis experimentally, but confirmed natural cases on cannabis are rare. Mottled leaves usually have another cause. Label: Contested. See [HLVd and viruses](https://genetixbay.com/knowledge/diseases/hop-latent-viroid-and-viruses.md).

## Don't confuse with

- **Viroid**: no protein coat, no [genes](https://genetixbay.com/knowledge/glossary/gene.md).
- **Genetic variegation**: stable in a cut, not spreading.

## Related terms

[Viroid](https://genetixbay.com/knowledge/glossary/viroid.md), [Hop latent viroid](https://genetixbay.com/knowledge/glossary/hop-latent-viroid.md), [Beet curly top virus](https://genetixbay.com/knowledge/glossary/beet-curly-top-virus.md), [Leafhopper](https://genetixbay.com/knowledge/glossary/leafhopper.md), [Whitefly](https://genetixbay.com/knowledge/glossary/whitefly.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. Punja ZK, 2021. Emerging diseases of Cannabis sativa and sustainable management. Pest Management Science 77:3857–3870. https://pmc.ncbi.nlm.nih.gov/articles/PMC8451794/
2. Hadad L, Luria N, Smith E, et al., 2019. Lettuce chlorosis virus disease: a new threat to cannabis production. Viruses 11(9):802. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6784094/
3. Punja ZK, Collyer D, Scott C, et al., 2019. Pathogens and molds affecting production and quality of Cannabis sativa L. Frontiers in Plant Science 10:1120. https://www.frontiersin.org/articles/10.3389/fpls.2019.01120/full