The Indiana Certified Crop Adviser panel this month includes Steve Gauck, an agronomy manager for Beck’s, Greensburg; Jeff Nagel, agronomist for Keystone Cooperative, Lafayette; and Marty Park, agronomist with Gutwein Seed Services, Rensselaer. 

 

While I have not had red crown rot (RCR) in my soybeans, I want to know the symptoms. How do I scout? Is there any way to prevent it? 

 

Gauck: Red crown rot can be easy and difficult to identify. From the windshield, it will look like many diseases, including sudden death syndrome (SDS). Symptoms appear during grain fill. Look for yellowing between leaf veins on upper leaves. Then look at the base of stems for reddish-brown, ball-like fungal growth. Dig roots, looking for a distinctive red/black discoloration. 

 

The best option is sending samples to the Purdue Plant and Diagnostic Lab for confirmation. Once found, there are no in-season treatments. We’re still learning about its movement, but early indications show that tillage and tillage equipment transport it field to field.  

 

Many seed companies are looking into variety tolerance, but that has been difficult to confirm. The only thing labeled today is a new seed treatment called Victrato. Early plots and tests I’ve seen show good suppression against many diseases, including RCR.

 

Nagel: Red crown rot infects roots early. First identified in Indiana in 2021, it was confirmed in 15 Indiana counties in ’25. Find a distribution map showing counties with positive identification at Crop Protection Network.

 

Yields can be negatively impacted by 40% to 50% where more severe. Like SDS and brown stem rot, foliar symptoms often don’t appear until R3 or after. Foliar symptoms may resemble SDS or BSR. As the disease progresses, roots show rotting. You can often see red fruiting bodies around the stem at the soil line. However, these fruiting bodies aren’t always present. The best way to confirm is to submit samples to a diagnostic lab. 

 

Current soybean varieties are susceptible. Two seed treatments are labeled for suppression: Saltro and Ilevo (2x rate). Recently, Syngenta received EPA registration for Victrato. Early performance has shown it to be a significant step up in suppression of RCR, resulting in significant yield protection. It also has activity on SDS, soybean cyst nematode, root knot nematode and several other nematode species.

 

Park: Red crown rot is easy to misidentify as SDS. Foliar symptoms look very similar, and they appear at the same time. Both diseases cause root rots that lead to necrosis in leaves. Cold, wet early conditions are associated with SDS, while warm, wet conditions are associated with RCR. With SDS, leaves tend to fall off petioles. Leaves seem to stay attached with RCR. Roots and lower stems on plants with RCR have reddish discoloration. With SDS, you might see blue-colored sporulation on tap roots. If you split the stem, you will see brownish vascular tissue. Submit samples for confirmation.  

 

No “cure” exists for RCR, but universities and the industry are working on best practices to handle it. Some seed treatments like Saltro, Cermax and Ilevo have shown some activity. There are also reports that fungicides Priaxor and Proline in-furrow might have some activity. Seed companies are working hard to find genetic solutions. Stay informed and know what happens in your fields.