Necrotic Ring Spot on lawns.
Necrotic Ring Spot (NRS) is a disease problem of Kentucky bluegrass lawns. NRS is a root rotting fungus most common in Kentucky bluegrass and other bluegrass bends. It can also be found on other turf types though not often. Necrotic Ring Spot commonly develops due to cool, wet weather in spring along with excessive amounts of nitrogen fertilizers and compacted soils. This disease is seen more often on established turf and is more severe on sites with little to no soil prepara