Soybean Production in Mississippi
Asian Soybean Rust
Asian
or Australasian soybean rust has been a problem in many parts of the
world since 1902 when it was found in Japan. Since that time, many countries
across many continents have been affected by this disease.
From 1997-2001, the countries of Uganda, Zimbabwe, and South Africa have confirmed the presence of Asian soybean rust. By the year 2000, rust had spread all the way to Paraguay, South America and later into other countries including Brazil, Argentina, and in 2004 the country of Bolivia found soybean rust (Figure 3).
In the fall of 2004, it was found in several fields along the Mississippi River (Figure 1). Other states that discovered rust included Louisiana (the first place found in the continental US, November 10, 2004), Florida, Georgia, Alabama, Arkansas, Missouri, South Carolina and Tennessee (Figure 2).
The disease is thought to have arrived in the United States by wind currents associated with Hurricane Ivan. The locations that the pathogen was found along with the pattern that Ivan took suggest that the spores came in from South America on the hurricane winds. The first confirmed case in Mississippi was found July 13, 2005.
The
major impact that soybean rust has on soybean production is YIELD! Protecting
yields is the number one concern for growers. Rust has shown to affect
yield tremendously. Yield loss as high as 100% has been seen in some
countries. (Figure 3 and Figure
4).
There are no resistant varieties and no cultural practices available to control this disease at this time. The only option available to producers is the use of fungicides. Fungicides have shown to be beneficial in other countries (Figure 5).
Pictures and slides in this subject area have been shared commonly among plant pathologists, soybean agronomists, and many others dealing with Asian soybean rust. They are courtesy of APHIS, USDA-ARS (Dr. Monte Miles, Dr. Glen Hartmen), EMBRAPA, a private consultant in Zimbabwe, BASF Chemical Co., and Syngenta.