There were multiple reports of Sudden Death Syndrome in soybeans this past year in Tennessee.
The cooler, wet season helped promote the disease in susceptible varieties, but the presence of soybean cyst nematode can also increase the effect of SDS.
The combination of the fungus that causes SDS (Fusarium solani f. sp. glycines) and SCN will have a greater effect on yield on a variety that is susceptible to both pathogens than either pathogen would on its own.
Both pathogens are in Tennessee. I recommend sampling for SCN.
SDS is usually more severe in saturated soils, such as in low spots and in irrigated as opposed to non-irrigated fields. Fields that develop SDS are likely to develop the disease during subsequent years when favorable weather conditions occur.
Management options include planting a resistant to moderately resistant variety, using cultivation practices that prevent or reduce soil compaction and improve drainage in low spots, and reducing soybean cyst nematode populations.
The best time to sample for SCN is in the fall, or now, when the population is the highest.
More information on how to sample for SCN and mailing instructions can be found at UT Crops Blog Nematode Sample How To  and Nematode Sampling Form. There is no charge for processing of SCN samples.
More information on SDS can be found in the article posted earlier this year at news.utcrops.com Sudden Death Syndrome in Soybeans. 
One management option is to plant a resistant to moderately resistant variety. Disease ratings on soybean varieties can be found within the UT Variety Trial Data and Soybean Disease Rating Summaries. 
More from Southeast Farm Press