Grainnet

Asian Soybean Rust Confirmed in Southern Illinois

Bloomington, IL-- Asian soybean rust was discovered in a field in southern Illinois this week.

A sample from Massac County, which borders the Ohio River across from Kentucky, was confirmed as rust by the U.S. Department of Agriculture (USDA).

“Asian soybean rust and its potential for economic yield damage remains one of our primary concerns, especially after rust was first discovered last year in eight Illinois counties,” says Ken Dalenberg, Illinois Soybean Association (ISA) Supply Committee Chair, and grower from Mansfield, IL.

“Growers should periodically visit the checkoff-supported Web site, www.soybeanrust.org.

"The site, in conjunction with the Illinois Sentinel Plot System, serves as an early-warning alert for tracking rust in the state.”

According to the USDA, 97 percent of Illinois’ soybean fields are turning yellow and 87 percent are shedding leaves.

University of Illinois Extension officials say due to the maturity of the plots monitored for rust, soybean leaves are being collected from fields that still have green leaves in a few counties to determine the distribution of soybean rust in the state.

“The stage of the soybean crop at this point in time is past the stage in which rust can cause economic yield loss,” Illinois officials stated in their scouting report.

“If a double-crop soybean field is in a growth stage prior to R6, it is extremely important to determine the yield potential before considering applying a fungicide.

"If the decision to apply a fungicide is made, a triazole/strobilurin mixture or triazole fungicide should be used.”

Growers can get updated management guidelines and tactics from the www.sbrusa.net or www.soybeanrust.org sites.

If you suspect rust, take the leaves to the nearest Illinois Extension Office.

The Digital Distance Diagnostics Imaging (DDDI) system can help evaluate suspicious leaves.

Leaf samples can also be sent overnight to the University of Illinois Plant Clinic, 1401 W. St. Mary’s Road, Urbana, IL 61802; 217-333-0519.

The Massac County confirmation is the second in the Midwest this year.

Rust was confirmed in two southeastern Missouri counties as well, and has been discovered in more than 130 counties in 13 states this year – twice as many as in 2006.

For more information, call Kayla Rassi at 309-663-7692.