Anette Phibbs, Plant Pathologist with the Wisconsin Department of Agriculture and Consumer Protection, reports that preliminary results of the DATCP soybean survey show a lot of root rot disease (Phytophthora sojae) presently active in the state. From June 6 to 25, the pest survey team sampled 19 fields in 13 counties. Soybeans were in the early vegetative states. Lab testing of roots showed 11 out 19 (58%) fields tested positive for P. sojae. The counties surveyed so far are Iowa, Walworth, Kenosha, Lafayette, Grant, Green, Dodge, Ozaukee, Sheboygan Marquette, Winnebago, Fond du Lac, and Dane. Counties with root rot finds are in bold print. This high prevalence of Phytophthora root rot throughout the surveyed area is no doubt due to heavy rainfalls causing saturated soils and relatively low temperatures this spring which have been very conducive to this water mold. Counties were the problem was not encountered should not expect to be free from the disease. The survey will continue until 50 fields in all soybean growing areas have been sampled.
For more about Phytopthora root rot of soybean, visit an informational webpage by clicking here and scrolling down to “Phytophthora Stem and Root Rot” or download a UWEX fact sheet by clicking here.