Verticillium wilt manifests through the infection of the root system and subsequent colonization of the xylem by the fungal pathogen. The first external symptoms include slow yellowing and curling of the lower leaves, which eventually wither. A diagnostic sign is the browning of the vascular ring in a cross-section of the stem, and in cases of severe infection, a fungal growth may be observed on the plant surface.
The intensity of disease development depends on temperature conditions, with the range of +21°C to +26°C considered optimal. The disease is more pronounced in light soils, during sharp fluctuations in humidity and temperature, as well as in the presence of mechanical root damage or when growing monocultures. The pathogen is a polyphage and affects a wide range of agricultural crops.
Varietal resistance to this disease is based on a genetic mechanism that restricts the penetration and movement of the fungus through the plant's vascular system. During variety testing, the efficacy of cultivars is determined using artificial inoculation methods, which assess the visual degree of symptom development and the plant's ability to maintain productivity under infectious pressure.