Pleurostoma decline

Pleurostoma decline is a fungal disease affecting grapevines, caused by the pathogen Pleurostoma ootheca. It belongs to a group of pathogens involved in grapevine trunk diseases, which pose a significant threat to viticulture worldwide by reducing the lifespan of vineyards and compromising the quality of yields.

This pathogen primarily infects Vitis vinifera. Infection usually occurs through wounds, such as those left by pruning or mechanical damage caused by weather conditions. Once inside the vine, the fungus colonizes the xylem, creating obstructions that restrict the flow of water and essential nutrients throughout the plant.

Symptoms of this disease are characterized by stunted shoot growth, chlorosis, and the development of necrosis on leaves, which often show distinct patterns. When pruning older wood, dark or brown necrotic spots are visible on the cross-section, indicating the internal spread of the fungal infection within the woody tissue of the vine.

Environmental conditions, particularly high humidity and moderate temperatures, favor the release and dispersal of spores. The pathogen is spread over long distances by wind and rain splashes, while short-distance transmission is most commonly attributed to the use of contaminated pruning tools that move the fungus from infected to healthy vines.

Management of Pleurostoma decline relies heavily on preventive agricultural practices. Essential strategies include disinfecting pruning equipment, applying protective wound sealants to cuts, and removing and destroying severely infected wood. Ensuring clean nursery stock is also vital for the long-term health of new plantation blocks.

• Sanitizing pruning tools between vines.
• Applying fungicide pastes to pruning wounds.
• Removal of dead or heavily diseased wood.
• Strict hygiene in the vineyard environment.