Lawn Academy

Necrotic Ring Spot

Ophiosphaerella Korrae

Necrotic Ring Spot is commonly confused with Brown Patch but it actually has a larger outer ring and larger patch of green in the center.

Management

Use moderate to high amounts of phosphorous, nitrogen and potash. Minimize shade and apply fungicide.

Prevention

Raise mower height, avoid drought stress, and top-dress and aerate turf as needed.

Identification

  • 3 to 15 in patches
  • Yellow to light-green patches
  • Roots turn brown to black

Causes

  • Inhabits in moist soil
  • Thrives in higher temperatures and drought conditions
  • Compacted soil