Sudden Death Syndrome and Heavy Spring Rains: Another Bad Year?
Monday, December 28, 2015
By: Daren Mueller – Assistant Professor and Extension Plant Pathologist - Iowa State University
"Soybean sudden death syndrome (SDS) is one of the most damaging diseases of soybeans in Iowa and much of the Midwest. There are two phases of this disease – a root rot phase and a foliar symptom phase. SDS will be most problematic when weather conditions are conducive for disease development during both phases. The early cool, wet weather we have seen so far in 2013 helps increase the root rot phase of the disease. This can lead to development of severe SDS later in the growing season, as was seen in 2010 in Iowa.
In a recently published journal article, several plant pathologists at Iowa State University looked at rainfall, soil moisture and soil temperature in years with SDS (e.g., 2010) vs. years with little SDS (e.g., 2011). In this study, rainfall in April and May was similar in “SDS years” to “non-SDS years.” However, rainfall in June and July differed between disease years and non-disease years. This highlights the importance of rainfall a bit later in the season to trigger the second phase of the disease. Also, soil temperature was less correlated to SDS severity compared to rainfall."
Link to full study: Sudden Death Syndrome and Heavy Spring Rains: Another Bad Year?