Scientists Verify More Soybean Disease In Louisiana

Clayton Hollier, Whitam, Kenneth, Schneider, Raymond W., Boethel, David J., Benedict, Linda F.  |  4/26/2005 8:28:26 PM

News Release Distributed 11/16/04

Three of four samples tested from an inspection tour in Louisiana Thursday (Nov. 11) were confirmed as Asian soybean rust, a potentially devastating plant disease, today (Nov. 16) by officials at the U.S. Department of Agriculture.

The samples from three Louisiana parishes provide evidence that this fungal disease, which is spread by wind-borne spores, arrived in this country from South America via Hurricane Ivan, which struck the state about seven weeks ago.

"The sample locations indicate a path that matches the wind patterns of Hurricane Ivan," said Dr. Clayton Hollier, an LSU AgCenter plant pathologist and its principal investigator for the Southern Pest Detection Network.

The disease has been in South America, which is a major soybean-producing area, since 2001.

All evidence of the disease was found on soybean plants. The teams, which included scientists from USDA’s Animal and Plant Health Inspection Service and its Agricultural Research Service, also looked at kudzu – an invasive plant prevalent in Louisiana that can serve as a "host" for the fungus that causes the disease.

"It was just a matter of time before we found the disease in this country," said Dr. David Boethel, vice chancellor for research in the LSU AgCenter. "We were the last major soybean-producing country that didn’t have it."

Asian soybean rust is a fungal disease that interferes with photosynthesis. The plant cannot grow, so yields can be severely restricted.

Louisiana Commissioner of Agriculture and Forestry Bob Odom said he is confident Louisiana’s soybean producers will work with state and federal officials to minimize the effect on soybean yields next growing season.

"Our producers are concerned about this fungus and the effects it will have on their industry," Odom said. "We’ve always maintained a good relationship with the soybean-growing community and are going to continue to provide education and information about this disease and the fungicides that can be used to reduce its effects.

"My department will take the necessary steps to protect the growers and comply with all federal guidelines. We’ve all been working together the past week to identify the scope of this disease and are going to carry on the LDAF, USDA, LSU AgCenter team effort."

A USDA plant pathologist said the early discovery of the disease was unusual.

"The LSU AgCenter is to be commended for diligence in finding this disease," said Dr. Russ Bulluck, a plant pathologist in the USDA’s Animal and Plant Health Inspection Service. "It is amazing to find this at such an early stage."

Signs of the disease were discovered on Nov. 6 by Dr. Ray Schneider, an LSU AgCenter plant pathologist, during a tour of a production field at the LSU AgCenter’s research farm near Baton Rouge. The disease was confirmed as Asian soybean rust on Nov. 10 by the USDA laboratory in Beltsville, Md.

"In Brazil, yields on individual fields have been reduced by as much as 80 percent because of the disease," said Dr. Ken Whitam, LSU AgCenter plant pathologist.

The Louisiana parishes where samples were confirmed were Iberia, St. John and St. Mary.

"If it had to happen, it couldn’t have happened at a better time of year," said Craig Roussel, director of horticulture and quarantine programs with state Department of Agriculture and Forestry and one of two coordinators of the search effort. "More than 95 percent of the soybeans have already been harvested, so yields were not affected."

The other search coordinator was Bill Spitzer, state plant health director for the USDA’s Animal and Plant Health Inspection Service.

"Our focus now is on keeping this disease under control so it doesn’t hurt U.S. soybean production," Spitzer said.

Already, teams in other states are searching for evidence there, Spitzer said.

"Finding Asian soybean rust in this country means farmers will have to make changes in their soybean management practices," Whitam said. "They will have to be diligent in early scouting of the disease and use more fungicides, which will increase their production costs."

LSU AgCenter extension specialists will hold meetings with all the state’s soybean growers over the next couple of months to go over new recommendations concerning soybean production in Louisiana.


Clayton Hollier at (225) 578-2186 or 
Ken Whitam at (225) 578-2186 or 
Ray Schneider at (225) 578-4880 or 
David Boethel at (225) 578-4181 or 
Linda Foster Benedict at (225) 578-2937 or 

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