The arrival of soybean rust in the United States will present farmers with a number of uncertainties about exactly how to respond to the problem for the upcoming growing season, according to a recent study by Peter Goldsmith, assistant professor in the Department of Agricultural and Consumer Economics at the University of Illinois, and Gary Schnitkey, associate professor in the same department.

"The situation for farm managers in Illinois is much different than for producers in South America," said Goldsmith, who also serves as the Fellow in Agricultural Strategy at the National Soybean Research Laboratory. "Because the spores are present all year round in that region, growers can make the simple decision to apply multiple spray treatments each year. In the higher latitudes, where killing frost is present, the extent of the rust problem will differ considerably from year to year."

He noted that this key difference leaves Illinois growers with important decisions about what do about the threat for the upcoming growing season.

"Farmers will have to respond in some way to this new threat," said Goldsmith. "The decisions can range from doing nothing at all to applying multiple spray treatments. Growers can even decide to avoid planting soybeans completely. Organic soybean growers face a special challenge because there is no known organic treatment for rust."

According to Goldsmith, managers will need to focus on a few key variables in making the decision about how to respond to the rust situation.

"One variable creating uncertainty is the lack of experience in dealing with this disease," he said. "Most soybean growers are unfamiliar with using fungicides. Spraying for rust will add many new demands on the state's spraying infrastructure, protocols, and skills. More narrowly, growers have no previous experience with this disease to guide them in making decisions."

Goldsmith points out that there are also many uncertainties about the extent and range of the disease and how it will impact markets.

"We still do not know if the disease will even be present in 2005. If it is present, it is still uncertain when rust might arrive during the growing season or how it might be distributed across a particular region or farm," he said. "We also do not have any idea what its final impact will be on crop yields and prices."

He suggests in the study that one way of dealing with all the uncertainties is to focus management on a few key activities that are both controllable and have positive impacts. At the top of the list are management activities that focus on scouting, disease management, and spray-related decision making.

"There is plenty of time before the infection might make its appearance," Goldsmith said. "There is a large amount of high-quality educational materials available. This creates an opportunity for generating returns to good management. Those who are prepared will outperform those who are not."

A secondary area of concentration should be on cropping decisions and preparation of spraying equipment and materials. To make this process easier, Goldsmith and Schnitkey developed a decision support tool that is
available on the Internet at http://www.farmdoc.uiuc.edu/.

"The results show that the corn-soybean ratio will have less impact than the activities involved with scouting and good spray management," Goldsmith said. "Because timing of the spray is critical, growers should make sure
the proper equipment and fungicides will be available if needed. One way to begin this process is to develop good communications with fungicide sales representatives and spray contractors."

He points out that there are some variables that are completely uncontrollable, such as grain prices and the rate and location of the rust infection.

"These variables need to be factored in and analyzed, but they cannot be directly managed," he said. "The key is for growers to place the major focus on the high impact, controllable variables. That means learning about the disease and about how to scout and treat it."