UC IPM Online UC ANR home page UC IPM home page

UC IPM Home

Search

SKIP navigation

Home & garden
Agriculture
Natural environments
Exotic & invasive

Weather data & products
Degree-days
Interactive tools & models

Publications & more
Workshops and events
Training programs
Pesticide information

Grants programs
Funded-project results


 

How to Manage Pests

UC Pest Management Guidelines


The white mycelium and sclerotia of the southern blight pathogen.

Dry Beans

Southern Blight

Pathogen: Sclerotium rolfsii

(Reviewed 8/07, updated 8/07)

In this Guideline:


SYMPTOMS

Initial symptoms of southern blight include a yellowing of the foliage with slight darkening of the stem just above the soil line. Lesions on the stem at or near the soil line develop rapidly, girdling the stem and result in a sudden and permanent wilt of the plant. The fungus grows downward in the stem and root, rotting the cortical tissue. White mats of mycelium develop on the stem and in adjacent soil. In a few days, tan to brown spherical sclerotia (small dormant structures) about 0.06 inch (1.5 mm) in diameter appear on the mycelial mat. The abundant sclerotia are a good diagnostic feature of this disease.

COMMENTS ON THE DISEASE

High temperatures (above 85°F or 29°C) favor the disease. The fungus attacks a wide range of plants and survives for long periods in the soil as sclerotia. Southern blight is usually a minor disease of beans in California.

MANAGEMENT

Rotation to nonhosts such as corn or small grains for at least 2 years reduces inoculum. Burying plant refuse helps destroy sclerotia.

PUBLICATION

[UC Peer Reviewed]

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.

Top of page


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2007 The Regents of the University of California. All rights reserved.

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 How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/r52100911.html revised: August 8, 2007. Contact webmaster.