Symptoms and Signs
The internodes of infected plants shorten, resulting in extremely stunted plants. The upper portion of infected plants resembles a rosette or small flower bouquet. Leaves turn yellow or light green and may roll upward. Fruit are small and remain upright instead of drooping. Plants infected at an early age may die.
Comments on the Disease
The virus has a very large host range that includes many vegetables, field crops, and weeds. It is transmitted by the sugarbeet leafhopper, Circulifer tennelus, from susceptible host plants such as Russian thistle, which thrives in the coastal ranges or in desert areas. Curly top usually appears on scattered plants in pepper fields.
Management
Resistant varieties are available for beans and sugarbeet, but not for pepper or tomato. A statewide program to control the leafhopper vector with insecticide sprays on its breeding grounds limits the number of leafhoppers that move to agricultural areas. Control measures are not recommended for individual fields.