Pleurostoma wood rot

Pleurostoma wood rot is a significant fungal disease of grapevines caused by the pathogen Pleurostoma richardsiae. This fungus is part of the complex of pathogens involved in grapevine trunk diseases, which negatively impact the longevity and productivity of vineyards globally.

The primary host for this fungus is the grapevine (Vitis vinifera). The pathogen invades the vascular tissues and internal wood of the trunk and cordons, leading to a chronic decline of the vine as the fungal mycelium colonizes and degrades the structural tissues.

Typical symptoms include stunted shoot growth, chlorotic leaves, and a general loss of vigor. Diagnostic examination of the vine wood usually reveals characteristic brownish, necrotic lesions or streaks inside the trunk, which disrupts the transport of water and nutrients throughout the plant structure.

Environmental conditions such as high humidity and rainfall favor the dispersal of fungal spores. Infection primarily occurs through open pruning wounds or other physical damage to the trunk, making the timing of vineyard management practices crucial for preventing the entry of the pathogen into the wood.

Management relies heavily on preventative measures. Key strategies include practicing sanitary pruning, disinfecting tools between vines, and protecting fresh pruning cuts with sealants or specialized fungicides. Unfortunately, once the fungus has established itself deep within the woody tissue, chemical curative options are extremely limited, emphasizing the importance of early detection and hygiene.