By O. Neher and C. M. Ocamb
Cause The Beet curly top virus is spread in North America only by the beet leafhopper (Circulifer tenellus). The virus has an extensive host range. The leafhopper breeds readily on mustards and overwinters in perennial or winter annual weed hosts, carrying the virus to beets and other crops in spring.
Symptoms Young leaves roll in, pucker, develop blister-like thickenings, and are dwarfed. Vein clearing appears in young leaves followed by vein swellings on the lower sides, which appear knotted or gall-like. Roots are dwarfed, and rootlets may be twisted and distorted. Tap roots are covered with many rootlets ("hairy root"). Young plants die quickly.
Cultural control Planting resistant varieties is the most effective control practice. Minimum curly top resistance standards for approved varieties have been established by the Snake River Sugarbeet Research and Seed Alliance LLC for The Amalgamated Sugar Company LLC growing areas of Idaho, Oregon and Washington.
Chemical control Seed treatments with neonicotinoids are necessary to protect emerging beets from insect vector until plants develop full tolerance. Consult the PNW Insect Management Handbook for currently effective materials.