Peroneutypa dieback

Peroneutypa dieback is a fungal disease caused by pathogens within the genus Peroneutypa. This fungus is recognized as one of the contributing agents to wood-decay diseases in various woody plants, particularly causing significant damage to grapevine trunks and cordons over time.

The disease primarily targets the xylem and phloem of the host plant. As the fungus colonizes the wood, it disrupts the internal transport of water and nutrients. Over several seasons, this leads to progressive dieback of the affected branches and an overall decline in plant vigor.

Infected plants typically display localized necrosis on the woody parts, visible as dark, discolored areas on cross-sections of the vine. Externally, the bark may show signs of splitting, and small, black fruiting bodies may erupt through the surface, indicating the active reproductive stage of the pathogen.

Transmission occurs through airborne spores that land on fresh wounds. The risk of infection is significantly higher following pruning operations, especially when performed under wet and humid weather conditions. Once the fungus enters the open tissue, it establishes deep within the plant structure.

Management and prevention focus on strict sanitation. Growers should remove and destroy heavily infected plant material to reduce the inoculum pressure. Essential preventive measures include:

• Performing pruning during dry weather to minimize spore spread.
• Applying protective wound sealants or fungicides to fresh cuts.
• Disinfecting pruning tools between vines to prevent cross-contamination.
• Prioritizing the health of the vineyard through balanced nutrition and water management.