Source: Iowa State University
Soybean Sudden Death Syndrome (SDS) is widespread in Iowa. This year has had one of the worst epidemics since the disease was found in Iowa in 1994. Severely infested soybean fields can be found in every region in Iowa. It is easy to spot brown patches caused by SDS while you are driving the highways. Fields with large portions of premature defoliation can be found in early August.
The disease can be a big surprise to us. We have made good inputs in planting, enjoyed wonderful soybeans in July and were expecting good yield; and some may have made marketing movement. The disease suddenly turns the fields brown with sick looking plants in August. It strikes us, in many ways, like white mold.