U.S. farmers will have to beef up their capacity to spray soybeans with soybean rust fungicides if they hope to minimize crop losses from the devastating disease, which they are facing for the first time in 2005.
That's the conclusion of David Wright, one of the leading U.S. experts on soybean rust, according to an article in Southeast Farm Press.
“I question whether we have enough capacity to treat soybean acres in the time necessary to protect yield,” says Wright, director of production technologies for the Iowa Soybean Promotion Board. “With soybean rust, you have a very narrow window of opportunity to treat after the infestation has occurred.”
Typically, fungicides designed to stop soybean rust after it has infected a field must be applied within two to three days to protect yield.
Wright notes that it is unclear how widespread soybean rust will be this year. Since rust can't overwinter at freezing temperatures, it must travel with the wind from southern states, where it was found in early November. However, he believes the disease is likely to infest Iowa and other Soybean Belt states in 2005. Wright encourages farmers to develop a plan for treating rust after learning as much as they can about the disease.
“There really isn't much else you can do but be prepared with a management strategy that might include deciding to make your own fungicide applications,” he says.
Farmers wishing to reduce last-minute treatment hassles will have the option of applying a preventive treatment before rust strikes. These fungicides must be applied before first flower and prior to rust infestation. However, this approach forces growers to spend money for a treatment before they know it is needed, Wright says.
State officials from key soybean-producing states have approved several fungicides to treat soybean rust, which can cause total yield loss if left untreated. The cost of these fungicides has not been announced, but some fungicides are expected to cost $20-25/acre.