Bovista aestivalis

Bovista aestivalis is a species of fungus belonging to the Agaricaceae family. While primarily recognized as a soil-inhabiting saprotroph, in the context of professional turf management, it is often associated with the development of fairy rings and localized soil hydrophobicity, which severely impact the health and aesthetic quality of turfgrass ecosystems.

The pathogen is a basidiomycete fungus that develops extensive mycelial networks within the soil profile. The primary type of injury is physiological: the fungus colonizes the root zone, creating a hydrophobic layer that prevents water and essential nutrients from reaching the root systems of the host plants, leading to severe chlorosis and wilting.

Turfgrasses, particularly cool-season species such as Kentucky bluegrass (Poa pratensis) and creeping bentgrass (Agrostis stolonifera), are the primary targets for this fungus. These grasses are susceptible when planted in dense, heavily thatched conditions where organic matter accumulation provides an ideal substrate for fungal proliferation.

Symptoms of an infestation typically appear as irregular or circular patches of discolored, dying grass. The visual hallmarks include:

• Dark green rings with a necrotic center.
• Sparse grass growth within the affected area.
• Presence of small, grey, spherical fruiting bodies during humid periods.
• Localized dry spots due to water-repellent soil conditions.

Environmental conditions favoring the spread include excessive soil moisture followed by periods of drought, compaction, and high thatch levels. Effective control and prevention strategies focus on cultural practices: regular aeration to improve soil drainage, dethatching to reduce organic substrate, and balanced fertilization. Chemical control involves the application of systemic fungicides specifically targeted at basidiomycetous fungi when initial signs of ring formation are observed.