Cercospora Leaf Blight

scouted Oct. 5, 2023

Background
Soybeans were scouted at the R7 growth stage and yellowing discoloration and a bronzing purple/brown color of leaves was observed in random areas of the field.
Conclusion
This issue was confirmed by the NC State Plant, Disease and Insect clinic 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 include cultural like crop rotations with non-host crops and chemical with the use of fungicides.