Lasiodiplodia viticola

Lasiodiplodia viticola is a pathogenic fungus belonging to the kingdom Fungi, phylum Ascomycota, and family Botryosphaeriaceae. It is a well-recognized agent involved in the complex of grapevine trunk diseases (GTDs), particularly those categorized under Botryosphaeria dieback. This pathogen is known for its ability to colonize woody tissues and systematically compromise the plant's vascular integrity.

The primary host for this pathogen is the grapevine (Vitis vinifera). The disease manifests as necrotic lesions on trunks and cordons, which are often visible upon cross-sectioning as dark streaks or "wedges." The foliage of affected vines may exhibit symptoms such as chlorosis, stunted growth, and sudden wilting of branches during the peak of the growing season, significantly reducing the vine's lifespan and fruit quality.

The life cycle of Lasiodiplodia viticola relies on the production of conidia within pycnidia, which typically form on dead bark or infected wood. These spores are dispersed by rain splash and wind, seeking entry points to infect new hosts. Wounds caused by pruning, grafting, hail, or mechanical harvesting are the primary points of entry, as the fungus quickly invades the exposed tissue and establishes a deep, often permanent, infection.

Environmental conditions play a critical role in the severity of the infection. Periods of high humidity and moderate temperatures provide ideal conditions for spore germination and colonization. Furthermore, environmental stress—such as waterlogging or severe drought—weakens the vine's natural defenses, allowing the fungus to progress faster through the xylem vessels, leading to the gradual decline of the entire plant structure.

Integrated management is essential for controlling this pathogen, as there is no single curative treatment:

• Exclusion of the pathogen by sourcing certified disease-free nursery stock.
• Rigorous sanitation, including the removal and destruction of dead wood and cordons.
• Disinfection of pruning tools between vines to prevent cross-contamination.
• Application of protective wound dressings immediately following pruning cuts.
• Ensuring optimal vineyard nutrition to enhance the natural resistance of the vines.