How to Manage Pests

UC Pest Management Guidelines

SYMPTOMS

Plants infected with the Beet curly top virus show a striking down-cupping, puckering, and wrinkling of infected leaves. The leaves become thick and brittle and may turn dark green. The internodes of infected plants become shortened, resulting in a striking dwarfing and stunting of infected plants, particularly when plants are infected at an early stage of growth. These plants produce few if any pods. Plants infected at later stages of growth may senescence early, lose flowers, and produce stunted pods.

COMMENTS ON THE DISEASE

The Beet curly top virus has a wide host range that includes beans (especially blackeyes), tomatoes, peppers, sugarbeet, melons, and other crops. The virus overwinters in perennial and annual weeds (e.g., Russian thistle, mustard) in areas such as the foothills surrounding the Central Valley of California. The virus is acquired from these hosts by the beet leafhopper (Circulifer tenellus), and is transmitted to beans and other crops by this insect as it migrates from the foothills into agricultural areas. Yield losses caused by curly top vary considerably from year to year and can be associated with high leafhopper populations.

MANAGEMENT
Plant dry and snap bean varieties that are resistant or tolerant to the curly top virus in areas where curly top is known to occur. A statewide aerial spray program that targets areas harboring the leafhopper vector with insecticidal sprays before leafhopper migration may provide some control.

PUBLICATION

UC IPM Pest Management Guidelines: Dry Beans
UC ANR Publication 3446
Diseases
R. M. Davis, Plant Pathology, UC Davis
Acknowledgment for contributions to Abiotic Disorders:
A. E. Hall, Botany and Plant Sciences, UC Riverside
Acknowledgment for contributions to virus sections in Diseases:
R. L. Gilbertson, Plant Pathology, UC Davis
Acknowledgment for co-authorship of Ascochyta Blight:
C. A. Frate, UC Cooperative Extension, Tulare Co.

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