How to Spot Red Crown Rot in Soybeans

An old soybean foe has been spotted in Illinois soybean fields. Red crown rot (RCR), first spotted in 1972, can appear like a myriad of other common soybean diseases. Often confused with sudden death syndrome (SDS), its foliar symptoms can also appear similar to brown stem rot. Field surveys completed by the University of Illinois confirmed 14 counties had RCR in 2020 and 2021, mostly in central Illinois. RCR was also confirmed in fields in Kentucky two years ago.

Visual symptoms of RCR appear between R3 and R7 growth stages. Despite the similarities to other common diseases, two additional signs indicate your soybeans have RCR. If your soybean leaves stay attached to the petioles instead of dropping like they do with SDS, it could be RCR. Additionally, farmers can observe the base of the plant stem just above and below the soil line. Red fruiting structures at the base of an infected soybean plant are called perithesia and can indicate RCR.

Read more on RCR identification here.