What symptom is associated with grass blades splitting and containing black spores?

The symptom of grass blades splitting and containing black spores is most closely associated with stripe smut. Stripe smut is a fungal disease caused by Ustilago striiformis, which typically affects grasses. One of the key indicators of this disease is the appearance of black, spore-producing structures within the infected blades. As the disease progresses, it can cause distinctive splitting of the grass blades, giving rise to visible symptoms such as black patches or streaks.

This condition specifically stems from the fungal infection, which disrupts normal turf health and appearance. The formation of black spores is a hallmark of smut diseases as they produce spores that are key to their survival and spread. Understanding these symptoms helps in identifying stripe smut quickly so that effective control measures can be taken to manage the disease and minimize its impact on turf quality.