October 11, 2010
GREEN SOYBEAN PLANTS
I have received several calls and visited a few fields where there are instances of green soybeans remaining in otherwise mature fields.
A few of the fields appear to have Bud Blight. Bud blight is caused by the Tobacco Ringspot Virus (TRSV). In addition to remaining green, including retaining leaves late into the season, the plants also have a curving of the terminal in the shape of a crook, often called a shepherds crook. See http://www.plantsci.missouri.edu/soydoc/files/disease/bud.htm for more details, pictures, and links to other resources.
While bud blight may be the result of infected seed, it is far more likely the disease entered the field from a nearby inoculum source, such as hay fields, pastures and uncultivated areas, with insects being the most likely the vector. Thus, it usually begins on field borders and then moves inward.
Planting disease-free seed and maintaining good weed management are the best options for producers.
Soybean Sudden Death Syndrome (SDS)
Most of the fields with green soybeans are green stems with no leaves and no pods. The petioles (leaflet stems) are still present. Dr. Leonore Leandro, Iowa State University Plant Pathologist, believes that SDS started early in those plants, resulting in flower and pod abortions and quick defoliation. Her visual inspection of some of the plants does not suggest the presence of any other disease. She is conducting some laboratory work to confirm that no other disease organisms are present. Stay tuned.
CORN AND SOYBEAN YIELD TRIAL DATA
The 2010 Iowa State University Corn and Soybean Yield Trial data is beginning to show up at http://www.croptesting.iastate.edu/. As the raw data is accumulated at each location, it is being posted at this web site in spreadsheet format. Once harvest is complete, the data will be consolidated and analyzed and those results will also be posted at this web site.
FOR YOUR CALENDAR
Iowa Agricultural Aviation Association Mid-states Ag Aviation Conference
November 9 11, 2010, Bettendorf, IA
Iowa State University is providing conference participants the opportunity to receive their Commercial Pesticide Applicator Continuing Instruction Course (CIC) credits while at the conference. For details about the association and the conference, see http://iaagaviation.com/.
Integrated Crop Management Conference
December 1-2, 2010, Ames, IA
Details will be posted soon at http://www.aep.iastate.edu/icm/homepage.html.
2010 Ag Chemical Dealers Meeting
December 9, 2010, Iowa City, IA
While the target audience is those in the seed, fertilizer, and ag chemical industry, producers and others are always welcome to attend. Details will soon be posted at http://www.extension.iastate.edu/Pages/eccrops/AgChem.html.
Crop Advantage Series
January 6, 2011, Ottumwa (tentative)
January 7, 2011, Burlington, IA
January 19, 2011, Cedar Rapids, IA
January 26, 2011, Waterloo, IA
While the target audience is producers, those involved in seed, fertilizer, and ag chemicals and others are always welcome. Details will soon be posted at http://www.aep.iastate.edu/cas/.
If you have any questions, please feel free to contact the Iowa State University Extension Office.
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