Rust 'No Show' …So Far!

Plenty of eyes still watching. Tom J. Bechman

Published on: Jun 13, 2005

Every passing day means one less day that rust might awaken and reach Indiana in time to cause significant headaches yet this year. The threat is by no means passed for '05, but it's fair to say that it's a threat that's sleeping on the job for the time being.

"Asian soybean rust is certainly comatose so far," says Greg Shaner, Purdue University plant pathologist. Shaner is one of the primary Extension personnel in Indiana charged with monitoring for the first signs of rust.

"There's just not much if anything going on down South so far," he says. Rust was detected in Florida earlier this spring and some reports place it in Georgia as well. But there is simply very little activity even in those states at the moment. Dry weather there as well may be limiting movement so far,

"We're in a wait and see mode," Shaner says. "Our soybeans are still early in the vegetative process, so there's plenty of time for things to change. But it's just not happening yet."

If dry weather conditions over the Corn Belt, centered in Illinois, continue and expand, that would likely not favor spread and development of rust in soybeans. Besides not being conducive for spores to develop if they were here, there's another factor. Ag climatologist Jim Newman notes that if zonal flow develops across the Corn belt, as he expects, most storm tracks will move east to west. Besides usually resulting in less rain than normal, it also means that it might be less likely that storm tracks would stream up from the southern states. Without storm tracks moving spores from the south to the north, spread of rust might again be less likely this year. The emphasis is on this year. Nearly all knowledgeable agronomists and crop consultants agree that rust will eventually make it to Indiana. It's a matter of when and where. And 'when' may or may not be this season. Or if it is this season, it may not be early enough to pose a real threat.

Nevertheless, Shaner and many others remain vigilant. "We've got sentinel plots out to help detect first signs of rust should it appear," he notes. "And we're putting out more."

In addition, fertilizer and chemical dealers statewide are on the prowl. Many have plots out on local farm fields, and will be watching them as well.

Stay tuned should rust start to move. In the meantime, no news is good news.