Symptoms and Signs
Curly top symptoms include dwarfing, yellowing, and rolling of upper leaves. Leaves near the growing point develop yellow margins and become twisted and cupped. Veins of outer leaflets remain green while the rest of the leaflet turns yellow. Aerial tubers may form.
Comments on the Disease
The virus is transmitted by the beet leafhopper, Curculifer tenellus. Curly top affects a wide range of crops and weeds. Both the virus and the leafhopper survive on a large number of wild plants and weeds.
To prevent curly top outbreaks, the California Department of Food and Agriculture carries out a statewide monitoring and treatment program for the beet leafhopper vector. Beet leafhopper populations are monitored in foothill areas in spring. Locations where high populations have congregated are sprayed before they can move into agricultural fields. Treatment of beet leafhopper by growers is not suggested for preventing curly top.