A team of soybean rust experts found soybean rust active on kudzu in nine counties in central and northern Florida last week, including in one county that did not have soybean rust in 2005.

The counties were reported positive as of today on the USDA soybean rust site.

Scott Isard, Glen Hartman and four graduate students from the University of Illinois and Penn State University drove two vehicles for 2,500 miles around Florida from Jan. 11 to Jan. 13, according to today's updated state commentary by James Marois, University of Florida plant pathologist.

Isard is professor of aerobiology with the Computational Epidemiology and Aerobiology Lab at Penn State. Hartman is a USDA-ARS research plant pathologist at the University of Illinois. Both have worked extensively on soybean rust issues.

The team's intensive scouting resulted in positive finds of soybean rust in nine Florida counties: Polk, Duval, Leon, Alachua, Pasco, Hernando, Hillsborough, Lee and Gadsden. Polk county was the only one of the nine counties with no soybean rust finds in 2005.

They visited all the positive kudzu rust sites from 2005 that they could find, except for the Dade County site in Miami. Of all the sites that were positive for soybean rust in 2005 and that they were able to locate (13 out of 15), nine were positive for rust in 2006 in eight counties, according to Isard.

In addition, they observed 11 kudzu sites that were negative in 2005; one of these sites, in Polk County, is now positive.

Some of the sites had significant dieback, due to obvious frost damage in the north and/or natural decline in central and southern Florida. There was ample evidence of new growth at many of the northern and central Florida sites that had experienced significant dieback. A few sites in the south had no appreciable dieback.

Spore germination counts ranged from 3 percent to 78 percent. The lower percent germination were from dried leaves that had fallen from the plants. The highest percent germination came from green leaves, Isard said.

Up until these finds, soybean rust on kudzu in Montgomery County, Alabama, was the first and only reported U.S. find in 2006. Now there are 10 counties positive for soybean rust in the United States this year. Rust was found in 138 counties in 2005.

Source: StopSoyBeanRust.com, Florida state commentary on www.sbrusa.net and discussion with Scott Isard, Penn State.