Bunt of bentgrass

The fungus Tilletia decipiens is the causal agent of this specific smut disease. It is a basidiomycete pathogen that exhibits a high degree of host specificity, primarily targeting various species of bentgrass (Agrostis). The fungus interferes with the reproductive development of the grass, eventually replacing the internal tissues of the ovary with its own teliospores.

The primary hosts affected by this pathogen are grasses of the genus Agrostis, which are essential for turf management and pasture production. When infection occurs, the physiological capacity of the plant to produce viable seeds is severely compromised, leading to significant economic losses in the seed production industry.

Symptoms are typically observed during the heading phase of the grass. The most distinctive sign is the formation of bunted seeds or sori, which appear as swollen, often darkened structures instead of healthy grains. When these sori are disturbed, they release a fine, dark powder consisting of fungal spores, which may emit a faint, fishy odor associated with amines.

Development and spread of the disease are highly dependent on environmental factors, particularly moisture and temperature during the flowering stage. The spores can persist in the soil or adhere to the surface of seeds. Upon germination, the pathogen infects the developing meristematic tissues of the host, establishing a systemic infection that culminates in the smut symptoms.

Control strategies for Tilletia decipiens emphasize the importance of prevention and chemical intervention. Farmers are advised to prioritize the use of certified, disease-free seed lots. Furthermore, seed treatment with broad-spectrum systemic fungicides is considered the standard practice to neutralize soil-borne and seed-borne inoculum, thereby protecting the emerging seedlings from early infection.