Pleurostoma vine decline

Common symptoms include uneven growth, chlorosis, and progressive wilting of leaves on the affected cordons during the growing season.

Cross-sections of infected trunks or arms reveal characteristic dark, brownish to black necrosis in the woody tissue, representing damaged vessels.

Infected vines typically show shorter internodes and thinner shoots compared to healthy ones, indicating a reduced flow of nutrients and water.

As the disease progresses, whole cordons or even the entire vine may die, showing a typical dieback pattern that starts from the extremities.

The fruit on diseased vines is often of poor quality, showing reduced size and sugar accumulation, which directly impacts the commercial value.

The disease is caused by the fungus Pleurostoma ootheca, a pathogen that specifically targets the vascular system of grapevine wood.

This fungus acts as a xylem colonizer, where it slowly destroys the internal structure of the vine, leading to a long-term decline in plant health.

Infection occurs mainly through the colonization of pruning wounds, as the spores are easily dispersed by wind and rain splashes.

The pathogen is known for its ability to persist in a latent state within the woody tissue, making early detection extremely difficult for growers.

Its biological cycle is strongly linked to the physiological status of the vine and the presence of open access points in the plant's vascular system.

The development of the disease is favored by high relative humidity and moderate temperatures, which are optimal for fungal spore germination.

Pruning during rainy or misty weather creates high-risk conditions, as the fresh wounds remain wet and susceptible to spore infection for longer.

Mechanical injuries caused by hail, winter frost, or improper cultivation practices provide easy access points for the fungus to enter the wood.

Poor aeration within the vineyard canopy contributes to an environment conducive to the spread and establishment of the fungal pathogen.

Weakened plants under environmental or nutritional stress are significantly more susceptible to successful infection compared to well-maintained vines.

Pleurostoma vine decline is a destructive disease that significantly reduces the lifespan and productive capacity of a vineyard.

It causes systemic physiological disorders by blocking the water-conducting vessels, which leads to reduced yields and inferior grape quality.

The structural integrity of the vine wood is compromised, making the plants more prone to breaking and increasing sensitivity to winter cold.

The spread of the infection leads to economic losses due to the necessity of removing and replanting affected sections of the vineyard.

Because the disease is deep-seated in the wood, it is difficult to eradicate once established, often requiring rigorous management strategies.

The primary control measure is strict sanitary pruning: all wood showing signs of internal necrosis must be removed and destroyed by burning.

All pruning wounds should be treated immediately with protective fungicidal pastes to create a physical and chemical barrier against spore entry.

Tools used for pruning must be disinfected between plants to prevent the accidental transmission of the pathogen from diseased to healthy vines.

Maintaining strong plant health through balanced nutrition and pest control helps to boost the natural defenses of the vine against colonization.

Using certified, disease-free planting material is the most crucial preventative step for ensuring the long-term health of a newly established vineyard.