Ophiosphaerella patch

Ophiosphaerella patch is a destructive fungal disease caused by species of the Ophiosphaerella genus, most notably Ophiosphaerella herpotricha and Ophiosphaerella korrae. This pathogen primarily attacks the root system and crowns of warm-season turfgrass species.

The disease is characterized by the colonization of grass roots by fungal hyphae, which effectively inhibits the plant's ability to uptake water and nutrients. Over time, the affected root tissues decay, leading to the systemic collapse of the turfgrass stand in localized areas.

Symptoms often manifest as irregular patches or rings of yellow, thin, or dead grass that can persist throughout the growing season. As the fungus spreads outward from the point of infection, the centers of the patches may show signs of recovery, creating a distinct ring appearance.

The development and spread of Ophiosphaerella are driven by environmental conditions, particularly soil moisture levels and temperature. The disease is most active when soil temperatures range from 15°C to 25°C, especially in sites with poor soil aeration and accumulation of thatch layer.

Integrated pest management (IPM) is the most effective way to control this disease. Essential practices include core aeration to reduce soil compaction, deep and infrequent irrigation to encourage root growth, and the strategic application of fungicides when conditions favor pathogen development. Maintaining a balanced fertility program is also crucial for turf resilience.