The first Asian soybean rust reported in calendar year 2007 was found growing and sporulating last week on green kudzu in four Florida counties.

Scouts found the rust in Gadsden County in the Panhandle and in the north-central Florida counties of Alachua, Hernando and Marion, the USDA site reported Friday, Jan. 5. Officials say that if kudzu in the middle of the state and farther south is infected, it is likely producing spores now, too.

The Florida commentary from University of Florida plant pathologist Jim Marois said:

"Thus far, we have had a mild winter in Florida with a few light frosts in December and a lot of rain. Long-term forecasts are for a cool-wet winter.

"Most of the kudzu in the panhandle has been frozen back, but many patches in protected areas have green leaves and are producing rust spores. Kudzu in the middle of the state and further south still has green leaves and, if infected, is producing spores as well.

"Scouting this week found rust in Alachua, Hernando, Marion and Gadsden counties. More scouting will be done next week, and I expect most of the counties that were red in December will be red in January.

"In 2005, about 10 percent of the kudzu sites surveyed for rust were positive by the end of the year. When these same sites were surveyed in 2006, about 40 percent were infected. We plan to visit these same sites again in 2007.

"Not until the epidemic is fully developed on the kudzu will we know the true spore production potential of the Southeast and what it will mean for rust on soybean in the Midwest. Of course, a severe frost would likely reset the clock with many positive kudzu sites losing the rust infection."

According to USDA records, these same four counties were among the first dozen in the country to have rust reported in January 2006. (Ten of those first 12 were in Florida, the rust overwintering on kudzu.)

Louisiana kudzu growing again; no rust found yet

Yesterday, Louisiana officials reported that kudzu is beginning to regrow in protected areas in nine known parishes after a few winter freezes. These kudzu patches all had ASR during 2006.

"Although regrowth is occurring, it is only a few days old, and no ASR has been observed on it," the state commentary said.

Additional Louisiana kudzu sites where soybean rust was known to occur during 2006 will be scouted during the next few weeks, it said.

To date, the four red Florida counties and nine green (recently scouted, no rust found) Louisiana parishes are the only spots of color on the USDA soybean rust observation map on the PIPE Web site, (PIPE stands for Pest Information Platform for Extension and Education.) The map was wiped clean at the start of the new year, in preparation for a new season of rust in the U.S.

SOURCE: Florida and Louisiana state commentaries on as reported in article on