Helminthosporiosis represents a group of diseases that manifest through the formation of leaf spots, the color and shape of which vary from light gray to dark brown with a distinct border. Under severe infection, spots coalesce, causing necrosis and drying of the leaf blade, and can also affect roots, stems, and grain, causing rots and darkening of the embryo.
Disease development is most intense in the presence of droplet moisture and air temperatures ranging from +20 to +30 degrees Celsius. The level of infection depends on the climatic conditions of the specific region, the degree of variety susceptibility, and the overall infectious background in the fields.
Variety resistance is ensured by the genetically determined ability of the plant to limit pathogen development, with resistance in some crops being directly linked to the cytoplasm type. During variety trials, resistance is assessed using scoring scales under field conditions, as well as by biotesting methods on selective media using fungal toxins.