July 26, 2006 | By: Laura Skillman

Another year of waiting and watching for soybean rust is about over for many soybean producers in the state as their beans are maturing and the disease has yet to make an appearance. Late-planted soybeans could still be impacted, but for now there is little cause for concern.

No soybean rust has been confirmed in any commercial soybean fields in the United States. In Kentucky, 22 sites in 19 counties currently are being monitored for soybean rust on either kudzu or soybean as part of the national soybean rust sentinel plot network.

“The risk of soybean rust in Kentucky is very low at this time; no control measures are warranted,” said Don Hershman, plant pathologist with the University of Kentucky College of Agriculture. “Full season soybeans are just about out of the woods for this year. Late-planted crops will be vulnerable for a time yet and could still be severely damaged by soybean rust if the disease moves into Kentucky during the next month.”

Hershman noted, however, that his observations on the disease are contingent on it “acting” like it did last year.

“By way of a disclaimer, it is possible that soybean rust could blow up and develop into an epidemic much faster than it did last year,” he said. “If that were the case, even full-season beans would be at risk. But the way things are looking now, that doomsday scenario is not very likely to happen this year. Who knows how soybean rust will develop in the future, so it would not be prudent to think that the low soybean rust in 2005 and now, apparently, in 2006 is the way it will always be.

“My point is that it would be a great error to let soybean rust pass off your ‘radar screen’ even if it never makes it to Kentucky this season,” Hershman said. “The odds are very high that we will have to deal with soybean rust in a significant way at some point in the future. We just don’t know when that will happen.”

Asian soybean rust was first discovered in the United States in November 2004. Since that discovery, crop and disease specialists across the soybean growing region have working to understand how the disease develops and its impact on the crop. They have also been educating producers, field scouts, agricultural suppliers and others about this new threat.

For the past two years, the disease as been slow to move from its overwintering locations in the far south into soybean producing regions. Most of the locations where the disease has been discovered have been on kudzu and in sentinel plots. 

Soybean rust has yet to be discovered on any of Kentucky’s soybean crop. It was found in November 2005 on a kudzu leaf in Caldwell County by Hershman. But Kentucky’s cold winter temperatures make overwintering by the disease unlikely.

Up-to-date information on soybean rust in Kentucky and across the country can be found on the Internet at http://www.sbrusa.net or by calling 888-321-6771.


Don Hershman, 270-365-7541, ext. 215