How to Manage Pests

UC Pest Management Guidelines

| All dry beans pests | All crops | About guidelines |

Dry Beans

Black Root Rot

Pathogen: Thielaviopsis basicola

(Reviewed 8/07, updated 8/07)

In this Guideline:

Symptoms and signs
Comments on the disease
Management

SYMPTOMS AND SIGNS

This disease occurs on blackeyes as well as on other dry bean types. Brown to black necrotic tissue develops on the below ground stems and roots. Fissures often develop in necrotic cortex tissue. Using a compound microscope the fungus can be identified in diseased tissue by the production of dark chlamydospores.

COMMENTS ON THE DISEASE

The fungus survives over a year in soil as chlamydospores. In blackeyes, Thielaviopsis basicola appears to be active on affected roots throughout the growing season.

MANAGEMENT

Long-term crop rotation to nonsusceptible crops such as grasses may help to reduce soil inoculum. Avoiding excess irrigation or long drought stress may help.

PUBLICATION

UC IPM Pest Management Guidelines: Dry Beans
UC ANR Publication 3446

Diseases

C. A. Frate (emeritus), UC Cooperative Extension, Tulare County
P. Gepts, Plant Sciences, UC Davis
R. F. Long, UC Cooperative Extension, Yolo County

Acknowledgment for contributions to Diseases:

A. E. Hall (emeritus), Botany and Plant Sciences, UC Riverside
R. M. Davis (emeritus), Plant Pathology, UC Davis
R. L. Gilbertson, Plant Pathology, UC Davis
S. R. Temple (emeritus), Plant Sciences, UC Davis

Top of page

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Acknowledgements Staff-only pages Subscribe (RSS) Contact UC IPM

Agriculture and Natural Resources, University of California

Accessibility Contact webmaster.