Curly Top
Beet curly top virus
2 host plants
Last updated
This profile contains verified disease data from extension databases. Regional field notes and expert review are in progress.
Curly top virus causes leaf curling and upward rolling of foliage on many hosts. You notice stunting and yellowing on affected plants. The virus is transmitted by leafhopper insects. Control through insecticide applications and removal of infected plants.
Start with cultural controls: remove infected tissue, improve drainage and air circulation, and keep foliage dry when possible. Curly Top responds best to early intervention, so scout regularly during the growing season and act at the first sign of symptoms. Chemical controls exist for severe cases but work best as preventive treatments before infection takes hold.
Quick Reference
Management
High-risk period is late spring through early summer (May-July in PNW) when leafhopper populations increase and migrate into crop areas. Young seedlings are extremely vulnerable to infection; early infection causes severe stunting. Mid-season and late-planted crops face lower risk due to reduced leafhopper pressure. Spring conditions and leafhopper overwintering success determine disease severity. Curly top is primarily a concern in dry western regions; western Washington rarely experiences damaging levels. Source: PNW Plant Disease Management Handbook
Warm temperatures (20-30°C) favor leafhopper activity and virus multiplication in both host plants and insect vectors. High leafhopper populations increase disease incidence. Susceptible crop varieties show severe stunting and yield loss. Virus infection early in plant development causes most severe stunting. Secondary infections occur as leafhoppers move through fields during the growing season. Native desert host plants maintain virus during winter in endemic areas. Source: PNW Plant Disease Management Handbook