Ophiosphaerella narmari spring dead spot

Ophiosphaerella narmari is an ascomycete fungus identified as a primary causal agent of spring dead spot, a devastating disease affecting warm-season turfgrasses. The pathogen specifically targets the roots, rhizomes, and stolons, leading to tissue decay and plant mortality.

This disease primarily attacks bermudagrass (Cynodon spp.), causing significant economic losses for golf courses and high-end landscaping enterprises. Its ability to colonize the root zone makes it particularly difficult to manage once the infection has become established in the soil profile.

The symptoms of the infection typically appear in early spring as the grass emerges from dormancy. Affected areas show circular or irregular patches of bleached, dead turf that persist throughout the growing season. Examination of the roots often reveals necrotic lesions and a lack of healthy, white root tissue.

Environmental conditions that favor the development of Ophiosphaerella narmari include cool, moist soil during the fall when the pathogen infects the roots. Poor drainage, compaction, and excessive nitrogen applications can exacerbate the severity of the symptoms during the following spring.

Integrated management is essential for control, involving practices such as core aeration, improving soil drainage, and applying nitrogen fertilizers with caution. Preventive fungicide applications in the autumn are often necessary to protect root systems before the pathogen becomes active.