Neofusicoccum stellenboschiana

The primary manifestation of the infection is necrosis of woody tissues, which often becomes visible upon transverse cutting of shoots or branches.

A characteristic sign of the infection is the appearance of dark stripes or necrotic sectors spreading from the sites of injuries or natural pores.

Externally, the bark may show signs of cracking and depression, indicating deep damage to the cambium and the vascular system of the plant.

As the disease progresses, leaves on infected branches start to yellow prematurely, curl, and wither, leading to overall plant decline.

In the final stages, drying of individual fruit-bearing branches or entire arms is observed, which critically reduces the productivity of the crops.

The pathogen is a microscopic ascomycete fungus, Neofusicoccum stellenboschiana, which belongs to the Botryosphaeriaceae family.

This pathogen is part of a complex of fungi causing wood diseases, often associated with esca and other forms of necrosis in grapevines.

The fungus is capable of surviving in infected plant debris, in the soil, and within the tissues of infected perennial plants for extended periods.

Reproduction occurs primarily through conidia formed in pycnidia, which develop on the surface of dead wood and bark tissues.

Spore dissemination in orchards and vineyards occurs passively: via rainwater splashes, wind, and through the use of contaminated pruning tools.

The growth of the fungus is activated under conditions of high humidity, which is essential for spore germination and the development of new fruiting bodies.

The temperature range for mycelial growth is quite broad, but moderately warm weather conditions are considered most favorable for its development.

Stress conditions in plants, caused by drought, frost, or mechanical damage, significantly increase susceptibility to this pathogen.

Improper pruning, which leaves large open wounds without disinfection, creates a pathway for the fungus to infect the woody tissues.

The presence of unremoved plant debris with signs of necrosis in or near the field contributes to a high background level of infection.

The disease causes significant economic losses by triggering the gradual dieback of productive branches, requiring costly corrective pruning.

Infected plants demonstrate a sharp decline in yields, as well as a reduction in fruit and berry quality due to impaired physiological processes.

The pathogen can completely destroy a young plant in case of early infection, as the mycelium spreads rapidly through the vascular system.

The difficulty in controlling this disease lies in the fact that the fungus resides deep within the wood, making contact fungicides largely ineffective.

Spreading the infection through contaminated nursery stock poses a threat of massive losses during the establishment of new commercial plantations.

The primary method of protection is strict sanitary pruning, including the removal and subsequent burning of all symptomatic plant parts.

All pruning tools must undergo regular disinfection with appropriate chemical solutions to prevent the mechanical transmission of fungal spores.

To protect wounds after pruning, the use of specialized wound paints or fungicidal sealants is recommended to isolate the cuts from the pathogen.

An important part of disease prevention is maintaining high agricultural standards aimed at strengthening plant immunity and reducing stress factors.

The application of chemical agents at this stage is limited; therefore, the focus remains on using healthy, certified planting material to avoid infections.