The pathogen is a facultative parasite that develops on living tissues, weakened plants, and plant debris. Externally, the pathology manifests as the appearance of a grey fuzzy growth consisting of fungal mycelium and spores, as well as watery spots leading to tissue softening and wilting of the affected areas.
Pathogen activity depends directly on environmental conditions. The disease develops most aggressively at temperatures between +15 and +25°C and high relative humidity above 80–90%. The presence of free moisture, high planting density, mechanical damage, and physiological weakness of the plants significantly contribute to the spread of the infection.
Varietal resistance is complex in nature and is determined by the morphological characteristics of the plants, their chemical composition, and ontogenetic differences. In the state variety testing system, phytopathological assessment is conducted on a scale from 0 to 5 points by analyzing the natural infection background, which allows for the identification of genotypes that are resistant, tolerant, or susceptible to the pathogen.