For many Iowa soybean growers, last year's problems caused by Sudden Death Syndrome, a yield-robbing soybean disease, are all too fresh a memory. In a fact sheet published last fall by Iowa State University and the Iowa Soybean Association, ISU plant pathologist Leonor Leandro offers a number of suggested steps farmers can take that can help lessen the impact of SDS.
1. Plant high-yielding soybean varieties that are resistant to SDS and to soybean cyst nematode.
2. Avoid planting soybeans in cool, wet soils.
3. Plant fields with a history of SDS last. But avoid planting too late,
especially in northern Iowa, and thus incurring a yield penalty.
4. Avoid soil compaction; it provides a wet environment and puts stress
on the soybean plant.
5. Crop rotation is not helpful. The SDS pathogen can survive in corn debris,
such as corn kernels and roots. SDS outbreaks can occur even after a few
years of continuous corn.
6. Consider SCN control in your SDS management strategy. These two troublemakers (SDS and SCN) often appear together.
7. Deep tillage may reduce severity of SDS on headlands and other parts
of the field where the soil is compacted. Tillage may also promote earlier
warming of soils. If tillage is considered to reduce soil compaction,
efforts should be taken to minimize soil erosion and maintain soil quality. To download the entire fact sheet, go to www.iasoybeans.com/productionresearch/publications/sdsfactsheet/SDSfactsheet.pdf. In addition, the ISU Department of Plant Pathology has prepared a new publication, "Sudden Death Syndrome-Resistant Soybean Varieties for Iowa". It is posted online at www.iasoybeans.com/productionresearch/publications/sds2011/sds2011.pdf.