2010 Crop Summary
North Carolina soybean producers are expected to plant in excess of 1.65 million acres of soybeans in 2010. Soybean planting was about 95% complete at the end of June. Planting was somewhat ahead of previous years, due to fair weather and more full season bean acres / fewer late planted beans resulting from fewer wheat acres left by spring 2010.
North Carolina soybean producers harvested 34 bushels per acre in 2009, tying the record set in 2004. A record 60,180,000 bushels were harvested from 1.77 million acres. The outstanding production reflected near perfect growing conditions for much of the season, with excess moisture impacting only late season growth and, of course, the harvest.
Soybean Rust Update August 2010
Steve Koenning, Extension Soybean Pathology Specialist, North Carolina State University, and Jim Dunphy, Soybean Specialist, Crop Science.
Soybean rust found in North Carolina!
Asiatic soybean rust has been identified August 30th from a research plot at Kinston, NC, in Lenoir County. There were none to very few pustules on any of the leaves inspected, and none were sporulating. We are not sure how the spores got there, or where they came from, since the nearest rust that has been reported so far has been is southern Georgia (see following section), and that is 270 miles(Murphy, NC) to 570 miles (Elizabeth City, NC) away from our North Carolina soybeans.
We would recommend that farmers with soybeans that do not yet have seeds big enough to swell the pods (stage R5), and that are within 100 miles of Kinston, NC, seriously consider spraying a fungicide to prevent/retard the development of rust. We would prefer a triazole type of fungicide, either alone or in combination with a strobilurin type, since the triazoles tend to be effective a little later into the disease’s development than the strobulurins. If other foliar diseases are also present or anticipated, the strobulurins tend to be effective on more of the other foliar diseases that we typically experience in North Carolina.
Soybean rust found in Georgia.
Dr. Bob Kemerait of Georgia Cooperative Extension Reported the presence of soybean rust today. Soybean rust was found on soybeans on a farm in Southern Georgia (Brooks County) commonly used for fungicide trials for Asiatic soybean rust.
Be aware that if the path of hurricane moves west of the current prediction it could transport spores from this region. Still, the amount of rust present to the south of us is very limited so chances of rapid spread remain low. Dr. Kemerait has recommended fungicide application for Brooks and counties adjacent to Brooks, but not all of Georgia at this time.
Soybean rust is confined to areas of North Carolina, Mexico, Alabama, Florida, Georgia, and Texas at this time. Soybean rust has not been found in South Carolina at this time. Most areas of North Carolina are still forecast to be too hot for further widespread infection of rust.
Koenning Dunphy Perspective on Asiatic soybean rust in 2010:
The lack of spread of soybean rust in 2010 is likely due to several factors: 1) soybean rust was just about “frozen out” of the US in the winter of 2009-2010, 2) an extremely hot summer restricted development
Of the rust pathogen, and 3) the lack of tropical systems that would transport spores northward thus far in 2010. There is still a chance we may find additional rust in 2010, but some of the crop is already past the stage where rust would affect it. Most of the soybean crop will be past the point where rust could cause yield loss in about three to four weeks.
North Carolina farmers should continue to monitor reliable reports of where else rust has been found. An up-to-date map of where rust has been found is at http://www.sbrusa.net. Fungicide recommendations for control of rust are at http://ipm.ncsu.edu/agchem/agchem.html. The current version of these NC updates should also be available at our Teletip line: 800/662-7301.
Soybean Rust – Reflections on 2005-2008
Soybean rust has been detected in North Carolina every year since 2005. Rust was found in 17, 44, and 6 counties in 2005, 2006, and 2007 respectively. In spite of a favorable fall environment, rust was only found in five counties in 2008. Fungicides were not necessary to control rust and most foliar diseases were minor in 2008. Only in 2006 was it recommended that fungicides be sprayed in the southeastern counties on late planted late maturity soybean. Yield increases in these areas were on the order of 4 to 5 bushels per acre.
Fungicides
The down side of fungicide application is the cost of the fungicide and application. The upside is protection from disease – preventing yield loss and protecting the crop.
Reasons to Apply Fungicides:
Presence of disease (Frogeye, Target Spot, Anthracnose).
High yield potential.
Premium for seed quality.
Consider how long it will take to get fungicide applied to needed acreage. Take into consideration that with wet conditions you may not be able to apply by ground! Also, consider that application at R5 with a strobilurin or Topsin M can protect seed quality if harvest is delayed.
Reasons not to Apply Fungicides:
1. Cost.
2. Soybean at or beyond growth stage R5.
3. Increased potential for development of a fungicide-resistant disease.
Resources for Soybean Rust in 2010
A soybean teletip message for North Carolina has been set up at 1-800-662-7301 (the same number as for the cotton insect update), with a message updated as necessary.
Soybean Rust Management in the Mid-Atlantic Region (old version and new) can be found at the SSDW web site http://cipm.ncsu.edu/ent/SSDW/, as well as the Soybean Disease Atlas. The Soybean Rust Management guide is paid for with USB funds. We will distribute 600 copies of the publication “USING FUNGICIDES TO MANAGE soybean rust” will be distributed to Agents, CCAs, and Dealers. A PDF version can be obtained at http://oardc.osu.edu/soyrust/. The Fungicide Manual actually contains more information than most growers are likely to need.
Some sources for more detailed information are listed below:
The USDA soybean rust web site
http://www.sbrusa.net/cgi-bin/sbr/public.cgi
The North Carolina Crop Protection Manual
http://ipm.ncsu.edu/agchem/6-9.pdf
Fungicide Manual
http://oardc.osu.edu/soyrust/