The highly contagious soybean rust disease has spread to a new county in Florida, the second finding in a month, state scientists said on Tuesday. The University of Florida confirmed soybean rust on "old and new kudzu leaves" in Hernando County on the Florida Gulf Coast. Kudzu is a widespread weed in the South-eastern United States. Asian soybean rust, which can slash soybean crop production by up to 80 percent, was discovered in the United States for the first time last year.
The fungus, which does not harm humans, infected fields in nine Southern states in 2004.
Soybean rust was found for the first time this year in a kudzu plant in Pasco County on February 23. Florida is not a large soybean producer.
The US Agriculture Department estimates an outbreak in the United States could cost the American farm economy between $240 million and $2.4 billion this year.
Planting season for soybeans does not start until May.
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.