Soyabean rust has spread to Arkansas, the first major US soyabean-producing state infected with the contagious fungus that slashes crop production, Arkansas officials said on Monday. Arkansas is the sixth US state to be infected with the disease since it was initially discovered in the mainland United States less than two weeks ago.
The fungus, which withers the leaves of the soybean plant, has already been found in Louisiana, Mississippi, Florida, Alabama and Georgia. The wind-borne disease does not harm humans but can cut soybean crop yields by up to 80 percent.
"While growers have to be concerned, the University of Arkansas Division of Agriculture advises that panic is not warranted," said university officials, who found the disease in a field in Crittenden County.
Richard Cartwright, plant pathologist with the university, said scientists were testing more suspect fields throughout the state and expected to confirm more crops had been infected.
Arkansas harvested about 125 million bushels of soybeans this year, ranking ninth among US states. Farmers fear the fungus will spread to big soybean states such as Iowa and Illinois by next year's growing season.
Soybean futures at the Chicago Board of Trade rose on Monday, partly due to soybean rust concerns. At the close, soybean futures for January delivery settled at $5.54-1/2, up 4 cents a bushel.
USDA scientists released late Monday a summary of a computer analysis that tried to simulate how soybean rust spores were blown into the US Gulf states by Hurricane Ivan in mid-September.
The source of the fungus was assumed to be a 17,000 square kilometer area of soybean fields in Colombia and neighbouring countries infected with the disease, USDA said.
The analysis also looked at wind direction, air pressure and ultraviolet exposure to calculate the spread of the rust.
The disease is characterised by reddish brown lesions on soybean plants that make them shed their leaves. It spread from Asia to Africa and Latin America, devastating crops in many countries.