Soyabean rust, a contagious fungus that can sharply cut crop yield, was discovered for the first time in Texas, the US Agriculture Department said on Thursday.
Texas is the eighth state infected with soyabean rust disease this year.
The USDA said on its rust-monitoring Web site that soya rust was found on a patch of kudzu in Texas' Liberty County, between Houston and the Louisiana border.
Soyabeans growing in the area have matured and will soon be harvested, it said.
"Any confirmation of (soyabean rust) on kudzu in east Texas during the rest of 2005 will be of scientific importance, in identifying movement of (soyabean rust) spores," USDA said.
While additional cases of the highly contagious fungus could be found in the United States, much of the soyabean crop has been harvested so the disease will not trim yields or cause economic damage.
Since soya rust was first discovered in the continental United States one year ago, the fungus has remained in the southern part of the country.
Rust can cut soyabean crop yields by up to 80 percent, if not detected and treated early. The spores thrive in warm, humid weather under cloudy skies, and are spread by the wind.