Turf IPM Advisory • Turf 2017 Fertilization, Necrotic Ring Spot, Overseeding October 10, 2017535 Views Print or PDF Click here for this issue, which contains updates on: Necrotic ring spot causes dead patches of turf that may regrow in the centers. Late Fall Fertilization of Athletic Fields Necrotic Ring Spot Overseeding Recommended Cultural Practices for Fall