Published on Thursday, July 11, 2019
CLICK HERE FOR A DOWNLOADABLE VERSION OF THIS AGRONOMY TALK UPDATE
Sudden Death Syndrome (SDS), caused by Fusarium virguliforme, is a soybean disease that has grown in importance for farmers over the past 20 years. Today, it is ranked second only to soybean cyst nematode (SCN) as the most detrimental cause of annual damage to soybean yields. As the soybean-growing region has expanded to the North and the West, SDS continues to spread to new fields and to larger areas of fields that have already been infected. The severity of SDS damage varies from area to area and field to field, but yield reductions associated with SDS typically range anywhere from 20 to 70%.
SDS FAST FACTS
SDS infection occurs early in the season, but symptoms are usually not visible until mid-summer. During the vegetative growing season, foliar symptoms can appear and then be obscured by rapidly growing new leaf tissue until the disease catches up and manifests in more widespread foliar damage. The above-ground symptoms are caused by a toxin produced by the fungus that is then translocated throughout the plant. The appearance of symptoms is often associated with weather patterns of cooler temperatures, overcast skies, and high rainfall during the late flowering (R2) to early pod-fill (R4) growth stages.
CONDITIONS FAVORING SDS DEVELOPMENT
Both industry research and farmer experience have verified that today, cultural practices and integrated pest management (IPM) actions are critical in managing SDS. This starts with maintaining adequate soil fertility and reducing compaction from all field operations. Also, controlling weeds, diseases, and insects can help minimize external stresses, which will ultimately improve soybean growth and plant health. The ultimate goal is to enable the plant to better withstand the effects of SDS.
DIFFERENTIATE BETWEEN SDS AND BROWN STEM ROT
Both diseases will result in similar foliar damage. Sudden Death Syndrome will show symptoms on the outside of roots, but the pith at the center will be white, firm, and healthy. Brown Stem Rot creates brown piths in the root system. See Figure 3 above.
SDS cannot be treated once the fungus has infected the plants. The best strategy to limit the impact on your fields is to employ long-term management strategies. Investing in tile drainage, protecting your seed with a comprehensive seed treatment, and managing SCN pressure can all make a difference in your fields.
FURTHER READING: https://soybeanresearchinfo.com/soybean-disease/sudden-death-syndrome/
Author: Mike Blaine
Categories: Agronomy, Agronomy Talk
Tags: soybeans, Soybean Diseases, Sudden Death Syndrome, SDS