Plans under way to
monitor location and spread of soybean rust
Send a link to a friend
Before soybean rust can become a
problem in Illinois, the pathogen that causes the disease will
likely overwinter in the southern United States, Mexico or the
Caribbean region. From there, the spores must be blown by the wind
into Illinois for a widespread outbreak to occur.
"Among the many unknowns concerning
soybean rust is where the pathogen will actually overwinter," said
Dean Malvick, plant pathologist with University of Illinois
Extension. "We also need to find out how the spores may be dispersed
by wind to Illinois at critical times for infection. To help deal
with this problem, a coordinated plan for soybean rust surveillance,
reporting and prediction is being developed by the UDSA and
representatives from industry, states and universities."
He notes that plans are already in
place for surveillance and prediction activities to determine
exactly where this disease has survived over the winter and when and
where it will develop this spring and summer.
"By late March or early April we
should have information on where and if soybean rust has survived
over the winter in the continental United States," Malvick said. "We
know the states and counties where soybean rust was found in
November and December 2004, but the overwintering locations have not
yet been determined."
Malvick points out that the frosts
this winter may have killed soybeans and leaves of the weed-host
kudzu at least as far south as Baton Rouge, La.
"This suggests that soybean rust may
be surviving only along the Gulf Coast," Malvick said. "Surveillance
work for soybean rust has been ongoing in some of the states along
the gulf, including Florida and Louisiana. As of Feb. 4, soybean
rust has not been detected in those areas in 2005. Early this spring
we may begin to learn of the distribution and severity of soybean
rust on kudzu, soybean and perhaps other hosts in the southern
[to top of second column in
Some models suggest
that the severity and incidence must reach at least a moderate level
in southern states, such as Arkansas, Missouri, Louisiana and
Tennessee, before there are sufficient numbers of spores to cause
problems in north central soybean production areas such as Illinois.
The reports of soybean rust infection from the south will likely be
used as an indicator of subsequent risk in north central states.
"The monitoring program will include
sentinel plots to detect soybean rust in overwintering areas and
soybean production areas," Malvick said. "Details on specific
numbers and locations of sentinel plots are still under discussion,
but each state will have these plots in multiple locations."
Reports from survey teams and from
areas not represented by sentinel plots will also be part of the
monitoring program to provide information from the soybean producing
areas of the United States, as well as Mexico and the Caribbean
region. This information will be entered into maps and made
available on a website to provide frequently updated information on
the confirmed distribution of soybean rust in the United States and
"In addition, a soybean rust
prediction system is under development that will deliver information
on spore dispersal and predicted disease severity," Malvick said.
"These monitoring and prediction systems will allow us to increase
our knowledge of soybean rust in the United States and improve our
ability to effectively manage this disease if it becomes a problem
of Illinois news release]