August 22, 2006

 

Asian soy rust found in 3 more southern US counties

 

 

Asian soybean rust has been found in three more counties across the southern US--including the first discovery of the fungal disease in South Carolina in 2006--the US Department of Agriculture said Monday (Aug 21) on its public rust website.

 

The website said soybean rust was found on a sentinel plot in Calhoun County, South Carolina, marking the state's first instance of the disease in 2006 and also the farthest north the disease has spread thus far this season.

 

Soybean rust was also reported in two locations in Hernando County in Florida, the site said. The Florida discoveries were on kudzu, a common weed.

 

A patch of kudzu in Liberty County, Texas, also was reported to have been infected with soybean rust, the USDA said.

 

A forecast posted on the website warns that the warm, moist conditions favourable to the disease may be present in some areas.

 

"The region from central Georgia to southern Arkansas will need to be vigilant for outbreaks of new rust" over the next three to five days due to scattered showers expected this week, according to the forecast. Increased risk is also present in north-western Louisiana and extreme northeast Texas, the forecast said.

 

Including reports of the disease on kudzu, Asian rust has been found on 35 counties, including five in Alabama; 13 in Florida; seven in Louisiana; six in Georgia; one each in Mississippi and South Carolina; and two in Texas.

 

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

 

In fact, the USDA said Monday that soybean rust can no longer be found on kudzu in Montgomery, Ala.

 

"The disease had previously been detected on five kudzu patches in the downtown (Montgomery) area where it had successfully overwintered," the USDA said, but the disease's presence hasn't been detected there since early June.

 

The department said a severe drought in central Alabama "likely had a direct impact on the pathogen's ability to survive."