Lincoln, Nebraska
October 5, 2007
Source:
Crop Watch News Service
- University of Nebraska - Lincoln
Soybean rust was positively
identified for the first time this week in Nebraska. It was
detected in a southeastern Nebraska soybean field.
Identification was confirmed at UNL's Plant and Pest Diagnostic
Clinic and the National Plant Diagnostic Network regional lab at
Kansas State University Friday (Oct. 5).
The disease was found on soybeans in southeastern Richardson
County near the town of Rulo and in Otoe County south of
Nebraska City. Leaf samples were collected from scouting
activity by Seth Watson, UNL soybean rust sentinel plot
coordinator, on Oct. 3.
Samples of hundreds of leaves were collected as part of scouting
activity with the national soybean rust sentinel plot system.
The sentinel plot system is funded by the Soybean Checkoff
program and the U.S. Department of Agriculture.
"As we are late in the season and many of our identified
sentinel plots are mature at this time, leaf samples were being
collected from fields with green leaves remaining starting on
Monday of this week," said Loren Giesler, UNL Extension plant
pathologist. "Based on where other reports of soybean rust had
been confirmed in southern Kansas and near Des Moines, Iowa, we
thought it should be here."
Giesler said the find is not unexpected as the disease has been
found in many states this year and has been moving north from
its overwintering location in the Gulf States and spread into
Texas earlier this summer. Institute of Agriculture and Natural
Resources faculty and staff are working to determine if other
fields in the state also have rust.
"Fortunately for soybean producers this year, the disease is
showing up too late for any impact on yield, and management will
not be needed," Giesler said.
Further finds on the distribution and severity of rust
occurrence this year will greatly help forecasting and modeling
research, which is ongoing.
"This demonstrates the ability of the fungus to move northward,
and had it occurred earlier in the year a totally different
scenario could have developed," he said.
Updates on where soybean rust has been confirmed in Nebraska and
other parts of the U.S. can be found on the USDA soybean rust
Web site at http://sbrusa.net.
"As mentioned, no management will be needed this year for
soybean rust in Nebraska, but growers should continue to stay
aware of where soybean rust is being found in future years,"
Giesler said. "Each year the disease has spread north and west
earlier, and this year we have observed a totally different
distribution compared to last year.
"No rust was observed in the western soybean states in the Great
Plains area last year compared to this year, and this year we
are seeing movement north further west than last year's movement
up the Mississippi Delta into Ohio."
If rust arrives earlier in the season in future years,
management options will include fungicide application, but once
the crop reaches the R6 growth stage (full berry stage), the
impact of soybean rust is minimal and most fungicides cannot be
applied based on the minimum pre-harvest intervals.
Producers are encouraged to contact a local UNL Extension office
for more information on soybean rust, call the soybean rust
phone hotline at (877) NEB-RUST or visit UNL's soybean rust Web
site at
http://soybeanrust.unl.edu.
Sandi Alswager Karstens
IANR News |
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