Ophiosphaerella agrostidis turf disease

Ophiosphaerella agrostidis is the fungal pathogen responsible for a destructive turfgrass disease known as dead spot. This disease is particularly problematic for high-maintenance turf areas, such as golf course putting greens, where it can cause significant damage to the aesthetic and structural integrity of the grass.

The primary hosts of this pathogen are bentgrass species (Agrostis), although it can potentially infect other grass varieties. The disease is characterized by its ability to spread rapidly in managed environments, causing circular patches that can merge and create extensive areas of necrotic tissue.

Symptoms initially appear as small, slightly sunken circular patches that range from light orange to reddish-brown in color. As the infection progresses, the roots of the infected grass become necrotic and turn dark or black. The plants within these patches die quickly, and the turf often fails to recover without specific intervention.

Environmental conditions that favor the development of Ophiosphaerella agrostidis include warm, humid weather with temperatures typically ranging between 20°C and 30°C. The pathogen thrives in soils with poor drainage or imbalanced fertility levels, especially when turf is maintained at very low mowing heights.

Management and prevention strategies focus on cultural practices and chemical control:

• Improving soil aeration and drainage to reduce moisture retention in the root zone.
• Managing nitrogen fertility carefully to avoid excessive growth during peak infection periods.
• Adjusting mowing heights where possible to reduce stress on the grass plants.
• Applying systemic fungicides, such as azoxystrobin or propiconazole, to suppress pathogen activity during high-risk seasons.