Grower Resource: SDS? Replant ASAP.

Facing SDS (Sudden Death Syndrome)? Don’t delay replanting—or you could be looking at yield loss.

A recent paper by Drs. David Marburger, Damon Smith and Shawn Conley reached three important management considerations for Wisconsin soybean growers:

  1. Wisconsin soybean growers should not sacrifice early-May planting dates that maximize yield in order to reduce SDS development and subsequent yield loss.
  2. Highest amount of SDS symptoms occurred in early-May planting dates. Despite this, highest yields also occurred in the early-May planting dates.
  3. Careful attention should be given to selecting cultivars with high-yield potential as the first priority, and then focus cultivar selection using company SDS ratings.

SDS is caused by a soil borne fungus, Fusarium virguliforme, and recent studies show the fungus has been found in 28 soybean-producing counties. The fungus can strike very early in the growing season—as soon as within 14 days of planting—and cool, wet weather makes infection more likely.

Unfortunately, while infection occurs early, foliar symptoms are not typically observed until much later (R3 to R5). While some farmers have reported yield loss of up to 80 percent, 5 to 15% yield loss more common. And foliar fungicide application will not control this pathogen.

Our experts conclude cultivar selection ti the best management practice for controlling SDS. So pick SDS-resistant cultivars whenever possible. If both SDS and SCN (Soybean Cyst Nematodes) are problems in a particular field, choose a variety with the best resistance/tolerance for them both.

Improving drainage and reducing soil compaction are other management practices to consider.

For more information about the disease process and managing SDS, CPN 1011 is a useful read.