Soybeans were scouted at the R6 growth stage and yellowing discoloration and a bronzing purple/brown color of leaves was observed in patches across the field.
Conclusion
This issue was confirmed by an NC State Extension Specialist to be Cercospora Leaf Blight. This foliar disease is caused by the pathogen Cercospora kikuchii, the causal agent of purple seed stain. This disease is common in soybeans, it rarely causes significant yield losses for North Carolina producers. Symptomology associated with cercospora leaf blight includes yellowing leaf discoloration with a purple or bronze tint, and as the disease progresses, small dark spots along major leaf veins. Management practices are cultural like crop rotations with non-host crops and chemical with the use of fungicides.