Posts tagged ‘soybean rust’

Soybean Rust – Close to Ohio in 2009 but no Cigar

Dr. Anne Dorrane, OSU Extension Pathologist, recently discussed how close soybean rust came to Ohio in 2009. Excerpted from the January 12, 2010 CORN Newsletter:

Soybean rust was a big topic again at the end of 2009. First detections in Kentucky were in early September and followed a month later on late planted soybeans in Southern Indiana. What was most impressive this year – was the amount of rust that built up in the southern states at the end of the season. A limited number of Mississippi producers had yield losses directly due to soybean rust based on reports from Dr. Tom Allen, their field crop pathologist. In addition to the soybean, the amount of kudzu that was also infected is also becoming an issue. The good news is that again, not all kudzu is susceptible to the current strains of soybean rust we have right now. And the kudzu patches that are Susceptible are getting placed on maps to make the scouting easier in the future.

The biggest announcement that was made at the 2010 APS National Soybean Rust Meeting held in December was that the sentinel plot system would change. And this is a good thing. We know more, we can be more efficient at scouting now that we know where to look and those of us in the north can get better and knowing when to look. There is no point in searching in Ohio, if the southern states are negative. For 2010, we will again be monitoring the maps and commentary from our southern colleagues at the Soybean Rust website ( We will continue to monitor in Ohio as soybean rust continues to approach the middle tier of states. Hopefully it will continue to miss us or arrive to late to have an impact.


January 20, 2010 at 8:15 am

Purdue: Soybean Rust Confirmed in Indiana

From: Purdue Plant & Pest Diagnostic Lab (

Soybean rust was confirmed in Indiana September 30th on soybean leaves collected in southeast Posey county.  Posey County is in the extreme southern and western part of Indiana. The soybean field where rust was found was at R7 and rust was detected at very low levels. Pustules were observed on 14 out of 100 leaves. Severity was low, with 1-2 pustules on each infected leaf.

In 2009, soybean rust has been found in 14 states and 293 counties in the United States, and in two states and five municipalities in Mexico.

Soybean rust was found in 392 counties in the United States in 2008. This is the highest number of counties reporting the disease since it was first discovered in the continental U.S. in 2004.

Unfortunately, there are additional hosts that can serve as overwintering reservoirs for the pathogen and allow for build-up of inoculum, in those environs free from freezing temperatures. The pathogen is well adapted for long-distance dispersal, because spores can be readily carried long distances by the wind to new, rust-free regions.

Although impossible to find symptoms this late in the year in Ohio (thanks to the October 1 killing freeze) the latest soybean rust information can always be found at

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October 7, 2009 at 11:37 am

Ohio Soybean Rust Update

In the April 7 issue of the Ohio State University Extension CORN Newsletter, Dr. Anne Dorrance discusses soybean rust in Ohio.  In the article, she points out that the critical time for Ohio soybeans is after July 4.  This is generally the time when soybeans begin flowering, and when (or if) soybean rust will be moving to Ohio from the south.  Weather patterns play a critical role during this time.  Dorrance writes:

Once our risk becomes moderate when a high level of rust inoculant is present in the southern US. We then will begin to monitor the storms, hurricanes and how many weeks it takes for rust to begin to be identified in Kentucky, Tennessee, Southern Illinois and Virginia. We have two major routes, the old blue mold pathway from Georgia and North Carolina as well as up the Mississippi and Ohio River Valleys. If it is a hot dry year, it took 4 to 6 weeks for rust to move which is too slow to impact Ohio soybeans. If it is wet and cool and big storms move in; it may be 3 weeks or less to jump from state to state. We will have to monitor the weather and conditions that influence infection.

Locally, Van Wert will have one of the ten sentinel plots in Ohio.  We strongly recommend you visit the USDA soybean rust website at for the latest rust information.

Full podcast available at:

April 15, 2009 at 7:30 am


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