Soybean South

 - Southern Specialists -

Soybean Rust Update For 2007

No soybean rust has been reported in 2007 in North Carolina or South Carolina, according to Dr. Jim Dunphy, North Carolina Extension soybean specialist.

Having received a clean report so far, should farmers in this area be concerned about rust this year?

“Concerned, yes, but not panicked,” Dunphy says. “We don’t know what rust is going to do in ’07, and the fact that we had it in ’06 is literally no indication of what we will have in ’07.

In 2006, soybean rust was confirmed in 42 counties in North Carolina and 21 counties in South Carolina.

“The spores will have to blow up from the real Deep South, probably the south half of Florida, just like they did in ’05 and ’06,” he adds. “But how soon they get here and what kind of weather conditions they encounter when they do will determine how we deal with it at that point.”

Dunphy says there is very little a farmer can do in preparation for rust other than be prepared to spray. He says they will continue the sentinel plot program, which provides an “early warning” for rust. “We intentionally have beans in the sentinel plots that are developing earlier than ‘farmer beans’ around them,” he explains. “That means they are most likely to be the first ones to be infected with rust. Plus we scout those fields regularly so farmers will have an idea of how close it is and how fast it is moving.”

If any rust is discovered or if they find out anything that is of importance to farmers or people in the state who advise farmers, Dunphy says the word goes out within the same day via email.

Magnolia state weighs in

Mississippi also is rust-free at this time, says Dan Poston, Mississippi State University Extension specialist. Last year, rust was confirmed in only nine of the state’s counties, so Poston is concerned that farmers will be more complacent this year since they haven’t had to deal with the disease.

“We’re telling producers to stay on their toes and listen to what is going on,” he says. “In our educational efforts, we’ve asked them to remain aware that we are going to have the opportunity to manage this pest at some point in time if we get the right environmental conditions. Last year was hot and dry, so conditions weren’t suitable for it.”

Reports from around the South

Sentinel plot updates, including rust information, can be found at Following are excerpts from some of the Southern commentary that was posted on the Web site during March.

Georgia: Tuesday, Feb. 27, kudzu mobile sentinel sites were scouted for soybean rust in Worth, Lee, Sumter, Terrell, Calhoun, Early, Miller, Seminole, Decatur, Grady, Thomas and Brooks Counties, located in southwest Georgia.

No new rust sites were found, and all kudzu was dead due to winter dieback, except for two locations (already confirmed) in Grady and Brooks Counties. These two sites are located in protected areas (behind buildings) in urban/industrial areas of the city. All leaves unprotected from the cold temps are dead.

Alabama: A combination of cold temperatures and mechnical destruction have killed back previously detected soybean rust-infected kudzu patches in Montgomery, Houston, Mobile and Baldwin counties in central and south Alabama. At this time the disease cannot be found within the state.

Look for soybean rust-infected kudzu in protected sites in urban areas. It can often be found on the south side of abandoned buildings, under or near bridges or in trees.

Florida: We have not found any rust in north Florida since the freeze March 5. We have prepared the sentinel sites across Florida and will plant next week.

The Florida rust “hotline” is a nationwide toll-free number (866) 361-9942 and can also be used to get updated information on soybean rust in Florida.

Louisiana: Kudzu regrowth is ocurring after spring temperatures are reaching the mid-80s during daylight hours. Scouting continues in the kudzu winter sentinel sites. These kudzu patches had ASR during 2006. Although regrowth is occurring, no ASR has been observed on it during 2007.

Most of the sentinel plots have been planted and kudzu sites where ASR was known to occur during 2006 continue to be scouted.

Texas: On March 1, a commercial soybean field near Monte Alto (Hidalgo County), which had soybean rust on remnant plants and volunteers was cultivated and planted to corn. The field was sprayed with Roundup, which would kill any soybeans, since they are not Roundup Ready.

The sentinel plot at the Texas A&M Station in Weslaco is still in the vegetative stage. There is no rust present.

Planting is underway for the commercial soybean crop in south Texas.

Rust Hides In Iowa Bin

On March 13, 2007, Iowa State University, Iowa Department of Agriculture and Land Stewardship and the Iowa Soybean Association jointly announced for the first time that soybean rust was found on plant tissue reported to be from Iowa. A sample of soybean seed, pods and a single leaf was taken from a bin in Iowa containing soybeans that were reported from an unthrifty field last fall. The soybeans were maturity group 3.7 planted in late May.

This sample was brought to the Iowa State University Plant Disease Clinic on March 8. Pustules and spores consistent with Asian soybean rust were found on the leaf. Efforts are underway to identify other remnant plant residue from the affected field and seed bins that may show symptoms and signs of the disease in order to clarify details of this event.