Finding new tools for management of red crown rot of soybean

Red crown rot of soybean is a new disease for Kentucky soybean farmers. It was found for the first time in Kentucky in 2021 and is currently known to be in three counties. Research conducted by the Bradley Lab at the University of Kentucky found that red crown rot can cause up to a 60% yield loss in soybean. With all known soybean varieties being susceptible to this disease, limited management options exist for soybean farmers.

The Bradley Lab tested multiple different fungicide seed treatments in field trials to determine if any were effective in reducing red crown rot symptoms. Two seed treatments were identified that consistently reduced red crown rot symptoms and provided soybean yields that were up to 60% greater than soybean yields compared to the control. The results of these trials have contributed to two commercially available fungicide seed treatment products to add red crown rot to their labels, making them available to farmers to use for protecting against severe yield losses that can be caused by red crown rot.

By managing red crown rot, soybean farmers can avoid economic losses. The use of effective fungicide seed treatments for management of red crown rot can result into a 20 bushel per acre yield increase over not managing red crown rot, which is worth approximately $240 per acre ($24,000 for a 100-acre soybean field that has red crown rot). If all 2 million acres of soybean in Kentucky were affected by red crown rot, management of this disease would be worth approximately $480 million. Fortunately, the results of field trials conducted by the Bradley Lab have helped Kentucky soybean farmers avoid extreme losses caused by this important disease.