Stephen J. Toth, Jr. and Thomas A. Melton, editors

The information and recommendations in this newsletter are applicable to North Carolina and may not apply in other areas.

Date: April 1, 2004

From: Steve Koenning, Extension Plant Pathologist, North Carolina State University

An important new disease threat to soybean is currently the cause of much concern in the agricultural community. Asiatic soybean rust, caused by Phakospora pachyrizi, has emerged as a major constraint to soybean production in South America since 1998. Another species of rust Phakospora meibomiae has been endemic to portions of South America for many years but is considered less of a threat because it is not as aggressive as the Asiatic soybean rust. During the 2003-2004 growing season in Brazil, Asiatic rust was severe in many areas and required sprays of fungicides Many industry leaders and some scientists predict that its introduction to North America is eminent and that it can have an impact on U.S. production. Some plant pathologists, however, suspect that it would be a minor problem if and when it does arrive in the U.S. Predictive models suggest that conditions in eastern North Carolina are favorable for development of an epidemic of soybean rust. The soybean rust pathogen is primarily tropical in distribution and would be able to survive winter in only the most southern portions of the U.S. There are alternate hosts for this pathogen in the U.S. including Kudzu. Should this disease be introduced to the U.S. an emergency registration of additional fungicides for use on soybean will take effect for three years.

If you suspect soybean rust the following actions should be taken:

1. Contact your Cooperative Extension County Agent, Regional Agronomist from North Carolina Department of Agriculture & Consumer Services, or a consultant for proper identification.

2. Send at least four or five leaf samples to the North Carolina State University Plant Disease and Insect Clinic (http://www.ces.ncsu.edu/depts/ent/clinic/Submit/submit.htm).

Address for U.S. Postal Service, UPS & FedEx:

Plant Disease and Insect Clinic Campus Box 7211
1104 Williams Hall
100 Derieux Place
North Carolina State University
Raleigh, NC 27695-7211

State Courier Address:

Plant Disease and Insect Clinic
Campus Box 7211 NCSU
Raleigh, NC
STATE COURIER: 53-61-21

The following web sites contain additional information on and pictures of symptoms and signs of soybean rust:

http://www.unitedsoybean.org/soybeanrustguide.pdf

http://www.ncpmc.org/soybeanrust/

http://www.plantmanagementnetwork.org/pub/search/topsearch.asp?page=http://www.planthealth.info/rust/rust.htm

http://www.plantmanagementnetwork.org/pub/search/topsearch.asp?page=http://www.apsnet.org/online/feature/rust/

Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.

Last modified on April 1, 2004 by Stephen J. Toth, Jr.