August 17, 2006

Soybean rust found in more locations in US state Louisiana

Asian soybean rust has been found in two additional parishes of Louisiana, bringing the total number of US counties found to be harbouring the plant disease in 2006 to 32.

"Asian soybean rust was confirmed on soybeans in Natchitoches Parish, Louisiana, on Aug 11 and in Avoyelles and Tensas parishes on the 15th," reported Louisiana state officials via the USDA's public rust website late Tuesday (Aug 15).

The airborne fungus has now been found on kudzu and in soybean sentinel plots across six parishes of Louisiana, five counties of Alabama, 13 counties in Florida, six in Georgia, one in Texas, and one in Mississippi. Rust has not yet been confirmed in a commercial US soybean field during 2006.

Although soybean harvest is underway in many areas of Louisiana, farmers with immature, late-planted beans are being advised to apply fungicides to fields that have "a good yield potential," in order to prevent potential yield losses.

Soybean rust causes premature defoliation of soybeans and can produce near-total yield losses unless countered chemically. The moisture-loving pathogen is a major plant pest in steamy South America, although its development has been stymied by drought in the US for the past two seasons.

The latest infection forecast published by USDA warned that increased rains could heighten the risk of rust development across the south-eastern US through Saturday, especially in Alabama, Georgia, Florida and South Carolina.