Neopestalotiopsis clavispora

Neopestalotiopsis clavispora is a pathogenic fungus that causes a destructive disease known as Neopestalotiopsis rot or leaf spot. This pathogen has recently emerged as a significant threat to global strawberry production, often causing rapid decline and plant death in both nursery and commercial field environments.

The primary host for this pathogen is the cultivated strawberry (Fragaria × ananassa). However, the fungus is opportunistic and can affect various parts of the plant, including leaves, crowns, petioles, and fruit. In some cases, it can colonize other stressed or wounded plant species in the proximity of infected fields.

Symptoms typically manifest as small, brown to reddish-brown lesions on the leaf surface. As the infection progresses, these spots expand, often forming a V-shape. A characteristic sign of the disease is the development of tiny, black, pimple-like fruiting bodies (acervuli) within the necrotic tissue. If the crown is infected, the plant wilts rapidly, showing internal browning of the root system.

Disease development is highly dependent on environmental conditions. High humidity, heavy rainfall, and temperatures ranging between 20°C and 28°C create the perfect environment for spore production and germination. The pathogen spreads rapidly through water splashing, contaminated nursery stock, and movement of infected debris or soil particles.

Effective management requires a multi-faceted approach. Preventive measures are crucial, such as starting with certified disease-free transplants and maintaining strict sanitation practices by removing and destroying symptomatic plant material. Field management should focus on improving airflow, using drip irrigation to avoid wet foliage, and applying recommended fungicides to suppress the fungal growth cycle.