August 29, 2006

Asian soybean rust found in US state Texas

Asian soybean rust was discovered Sunday (Aug 27) infecting soybeans in Liberty County, of far south-eastern Texas, 7 miles distant from a kudzu patch which was also found to be carrying the feared plant disease one week earlier.

With commercial soybeans in southern Texas quickly approaching full maturity, Texas A&M University extension plant pathologist Tom Isakeit said, "No fungicide applications are recommended at this time, because weather conditions do not favour development of an epidemic."

The airborne fungus flourishes in warm, damp, overcast weather, causing premature defoliation of immature soybeans and major yield losses, unless countered with fungicide.

"There have been scattered thundershowers during the past week, but hot, dry weather will not support rapid development of an epidemic in the next few weeks," said Isakeit via the USDA's public rust website.

Rust has now been found infecting soybeans and kudzu (a common broadleaf weed) in a total of 36 counties across Texas, Alabama, Florida, Louisiana, Georgia, Mississippi and South Carolina.

"Much like the 2005 season, more soybean rust finds are expected late this season through the next several months," noted USDA in the agency's national rust commentary.

The latest infection forecast published by USDA warned that high humidity levels and scattered showers could increase the risk of rust across coastal regions of Alabama, Mississippi and Florida through Wednesday.

"Winds from the south may become more south-easterly, which could increase risk along the eastern Gulf and South Carolina," as well, added the agency.