The Indiana Certified Crop Adviser panel includes Betsy Bower, Purdue Extension senior research associate, West Lafayette; Abby Horlacher, Nickel Plate Consulting, Sheridan; and Brian Mitchem, Farmer 1st Agronomy Consulting Services, Decatur.

 

We had red crown rot show up in a soybean field this year. Apparently, it will stay in that field for a while — at least, that’s what I’ve heard. Is that the case? Is there anything I can do to protect yield now? What about next year?

 

Bower: Yes, according to the Crop Protection Network information on red crown rot, it can still stay in a field as microsclerotia for several years in the absence of a suitable host such as soybeans. There is really nothing you can do to protect yield now. Watch fields after R3 for infection. You will find dying plants in irregularly shaped areas of the field. Foliar symptoms can look much like sudden death syndrome or brown stem rot, so be sure to check the lower stem for a reddish discoloration.

 

Targeted fungicide seed treatments like Victrado, Saltro and Ilevo can be used to protect soybeans in fields with known red crown rot issues. Once red crown rot is found in a field, harvest that field last so you limit the spread to other fields.

 

Horlacher: Yes, this is the case. Red crown rot can stay in the residue and soil for multiple years. Protecting yield now will be about standability and harvesting the field if stems are not holding up well. You have more yield with a standing plant than a plant laying down.

 

Next year, you will want to rotate toward a non-host crop like corn or wheat, along with improving any drainage in the field that may cause it to stay wet too long. Lastly, keep records to know how this disease might show up when soybeans return to the field.

 

Mitchem: Red crown rot is a soil-based disease, so once it’s established, it will be best to manage those impacted fields. Try to minimize moving tillage and planting tools from impacted farms to farms not affected. Planting under lower stress conditions is also a recommendation.

 

Crop rotation can help lower the soil disease load. And if possible, rotate away from soybeans for two cropping seasons before planting them again.

 

Seed treatments are the best defensive option. A new option called Victrato is labeled for control of red crown rot, as well as sudden death syndrome and soybean cyst nematode. Saltro has a 2EE label for suppression, and Ilevo can also suppress the disease.

 

Like other soilborne fungal diseases, there are no in-crop cures for the disease. Check with seed companies to see if they have any information on variety response to red crown rot.