Necrotic Ring Spot is caused by which pathogen?

Necrotic Ring Spot is caused by which pathogen?

• A. Ophiosphaerella korrae
• B. Puccinia graminis
• C. Rhizoctonia solani
• D. Sclerotinia homoeocarpa

Answer: (A)

Necrotic Ring Spot is caused by Ophiosphaerella korrae, an ascomycete fungus that infects cool-season turf grasses and creates circular or ring-like patches of dead tissue. This specific pathogen is what gives the characteristic rings rather than another turf disease. For comparison, rust pathogens like Puccinia graminis cause stem rust with orange pustules, Rhizoctonia solani leads to brown patch with irregular patches, and Sclerotinia homoeocarpa causes dollar spot with small spots that don’t form rings. The ring pattern and the link to Ophiosphaerella korrae are what identify this disease.

Necrotic Ring Spot is caused by Ophiosphaerella korrae, an ascomycete fungus that infects cool-season turf grasses and creates circular or ring-like patches of dead tissue. This specific pathogen is what gives the characteristic rings rather than another turf disease. For comparison, rust pathogens like Puccinia graminis cause stem rust with orange pustules, Rhizoctonia solani leads to brown patch with irregular patches, and Sclerotinia homoeocarpa causes dollar spot with small spots that don’t form rings. The ring pattern and the link to Ophiosphaerella korrae are what identify this disease.