Paspalum anthracnose

Pathogen and disease type. The causal agent of Paspalum anthracnose is the pathogenic fungus Colletotrichum paspali, an ascomycete. This disease is a classic form of anthracnose characterized by necrotic tissue collapse. The pathogen aggressively colonizes the host plant tissues, utilizing enzymes to break down cell walls and extract nutrients, which leads to rapid wilting and plant decline.

Affected crops. The disease primarily impacts species within the Paspalum genus, which are popular turfgrasses in tropical and subtropical climates. These grasses are valued for their density and heat tolerance, yet Colletotrichum paspali targets them specifically, particularly in intensively managed landscapes such as golf courses, parks, and sports fields.

Symptoms and signs. Clinical signs of infection include small, chlorotic spots on leaves that eventually enlarge and turn dark brown or tan. A hallmark of this disease is the appearance of tiny, black, hair-like structures known as acervuli, which emerge from the infected tissue and house the fungal spores. Severe infections result in thinning turf stands and large patches of necrotic vegetation.

Conditions for development and spread. The fungus thrives under warm, humid conditions, particularly when the leaf surface remains wet for extended periods. Air temperatures ranging from 20°C to 30°C are ideal for sporulation and germination. The pathogen spreads primarily through splashing water from irrigation or rainfall, as well as via mowing equipment that carries infected clippings across healthy turf areas.

Harmfulness and management measures. Paspalum anthracnose poses a significant threat to the aesthetic and functional value of turfgrass, leading to potential loss of cover. Management focuses on cultural practices such as improving soil drainage, managing irrigation to minimize leaf wetness, and regular aeration. Chemical control involves the timely application of fungicides, particularly those containing systemic active ingredients, to protect vulnerable growth stages.