Ilyonectria charruensis

Ilyonectria charruensis is a pathogenic fungus recognized as a significant agent in the complex of species causing black foot disease, particularly in grapevine cultivation. This pathogen attacks the root system and the collar of the plant, often leading to slow decline or the rapid collapse of affected vines.

The host range is primarily focused on perennial woody plants, with viticulture being the most economically affected sector. The fungus is capable of infecting vines at various ages, but it is particularly devastating for young vines in nurseries and newly established vineyards where it compromises the initial root development.

Clinical signs of an Ilyonectria charruensis infection include necrotic lesions on the roots and the base of the trunk. As the disease progresses, the plant exhibits signs of water stress, such as wilting, stunted shoot growth, and chlorosis of the foliage. Eventually, the root system decays, causing the plant to lose its ability to uptake essential nutrients.

The development and spread of the disease are heavily influenced by environmental factors, particularly soil moisture levels. High humidity in the root zone and compacted, poorly drained soils create an ideal environment for the pathogen to thrive and disperse. The fungus survives in the soil for extended periods using dormant structures, making eradication difficult.

Control and prevention strategies are crucial to mitigating the impact of this pathogen. Key management practices include:

• Sourcing healthy, certified planting material to avoid introducing the fungus into clean fields;
• Improving soil structure and drainage to prevent prolonged saturation;
• Practicing strict sanitation protocols, including the disinfection of pruning tools;
• Applying preventive fungicide treatments to nursery-grown rootstocks before planting.