Neofusicoccum vitifusiforme

Neofusicoccum vitifusiforme is a species of ascomycetous fungi within the Botryosphaeriaceae family, recognized as an important agent contributing to the complex of grapevine trunk diseases. These fungi are notoriously difficult to manage because they cause chronic, internal damage to the perennial woody parts of the plant, often leading to a slow decline of the vineyard.

The fungus predominantly affects grapevines (Vitis vinifera). The infection typically initiates when fungal spores land on fresh pruning wounds or other mechanical injuries on the vine. Once the pathogen colonizes the wood, it begins a slow process of decomposition, spreading systematically through the vascular system, which limits the plant's ability to transport water and essential nutrients.

Symptoms of Neofusicoccum vitifusiforme infection are often subtle in early stages, appearing as uneven shoot growth or leaf discoloration. As the disease progresses, necrotic lesions appear within the woody tissue. If a cross-section of the trunk or cordon is made, one can observe brown-streaked or wedge-shaped necrotic lesions, indicating that the vascular system is being progressively choked by the fungal growth.

The spread of this pathogen is highly dependent on environmental conditions. Rain splash is a primary mechanism for the dispersal of pycnidiospores throughout the vineyard. High humidity levels during the pruning season significantly increase the risk of infection, as these spores readily germinate in open wounds, making the timing of canopy and maintenance management crucial for success.

Prevention is the only effective strategy, as no curative chemical treatment currently exists for trunk-invading pathogens. Recommended practices include:

• Timing pruning operations to occur during dry weather to minimize infection windows.
• Applying protective wound sealants immediately after pruning to prevent spore colonization.
• Removing and destroying infected wood to reduce the local inoculum source.
• Maintaining vine health to improve the natural resistance of the plant against pathogens.