URBANDALE, Iowa — Sudden death syndrome is robbing Iowa soybean fields of yield potential.
Although not new, SDS is expanding into areas where it hasn’t been seen before.
"We’re looking at the possibility of reducing yield losses from SDS by impoving our current management practices,’’ said Palle Pedersen, Iowa State University Extension soybean agronomist.
SDS is caused by a fungal pathogen that enters the root within four days of germination. The pathogen remains in the root and crown area until the soybean plant enters the reproductive stage when it releases a toxin that moves throughout the plant, quickly killing the leaf tissue.
Foliar symptoms of SDS are easy to identify, but can be confused with those of iron deficiency chlorosis and brown stem rot. Producers should look for yellowing of the leaf tissue between the veins followed by the death of the yellow tissue.
"The best to manage this disease is to choose varieties with greater genetic resistance,’’ said David Wright, director of contract research and strategic initatives for the Iowa Soybean Association. "It is important for soybean producers and crop advisors to be able to accurately diagnose this disease.’’
Management options include planting varieties highly resistant to soybean cyst nematode and with greater resistance to SDS. The disease can’t be managed with fungicides.
Soybean producers should scout their fields to identify which soybean varieties are more impacted by SDS.
Decision aides are available to help farmers accurately diagnose SDS and other yield-robbing pathogens.
ISU and the Iowa Soybean Associiation recently released the Soybean Disease and Pest Management Field Guide with high-resolution color images and disease descriptions to help accurately identify most soybean diseases and insects.
A free copy is available by logging on to the ISU Extension publications store on the Web at www.extension.iastate.edu/store. Farmers can also call the ISA at 1-800-383-1423.