# Beet curly top virus

> BCTV, a leafhopper-spread curtovirus that stunts outdoor hemp and cannabis, curling and yellowing new leaves; there is no cure once a plant is infected.

- Canonical: https://genetixbay.com/knowledge/glossary/beet-curly-top-virus.html
- Also written: BCTV, curly top, curly top virus, Curtovirus
- 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"

Beet curly top virus (BCTV) is a single-stranded DNA [virus](https://genetixbay.com/knowledge/glossary/plant-virus.md) in the genus *Curtovirus* (family Geminiviridae) with a very wide host range, including sugar beet, tomato, pepper, beans and [hemp](https://genetixbay.com/knowledge/glossary/hemp.md). It is transmitted almost entirely by the [beet leafhopper](https://genetixbay.com/knowledge/glossary/leafhopper.md) (*Circulifer tenellus*). It is one of the most damaging viral diseases of outdoor hemp in the arid western United States.

## In practice

Infected plants show cupped, curled and mottled new leaves, yellowing that starts at the tips, stunting and a general "witches' broom" look, sometimes with twisted stems. Early infection can stop a plant flowering properly; late infection does less harm. Indoor grows rarely see it because the vector is an outdoor insect. Management is avoiding hot spots near weedy rangeland, using row covers on young plants, controlling host weeds and pulling infected plants. Testing by PCR confirms it, since symptoms mimic herbicide drift and nutrient problems.

## Don't confuse with

- **Hop latent viroid**: an RNA [viroid](https://genetixbay.com/knowledge/glossary/viroid.md) spread by tools and clones, not insects.
- **Herbicide drift**: distorted growth on many species at once along a field edge.
- **Broad mite damage**: twisted tips, but [mites](https://genetixbay.com/knowledge/glossary/two-spotted-spider-mite.md) are visible under 40x.

## Related terms

[Leafhopper](https://genetixbay.com/knowledge/glossary/leafhopper.md), [Plant virus](https://genetixbay.com/knowledge/glossary/plant-virus.md), [Viroid](https://genetixbay.com/knowledge/glossary/viroid.md), [Scouting](https://genetixbay.com/knowledge/glossary/scouting.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. Colorado State University (Mountain Scholar). Beet curly top virus - beet leafhopper dynamics in hemp in Colorado. https://mountainscholar.org/items/690318d0-f830-4090-b0a5-c1e18581d7b5/full
2. PNW Plant Disease Management Handbook. Hemp (Cannabis sativa) - Curly Top. https://pnwhandbooks.org/plantdisease/host-disease/hemp-cannabis-sativa-curly-top