The pathogens of Septoria blotch in triticale are represented by a wide range of species, among which Septoria secalis often predominates. The disease is also caused by Zymoseptoria tritici, Parastagonospora nodorum, Septoria avenae f. sp. triticea, and Septoria falcispora, with the species structure of the population heavily dependent on the region and the cultivar.
Symptoms appear as gray-green, yellow-brown, or brown spots of various shapes that eventually coalesce, causing necrosis of the leaf blade. A diagnostic feature is the formation of small black dots—pycnidia—in the center of the affected areas.
Pathogens infect the plant throughout the entire growing season, affecting leaves, leaf sheaths, and stems. The pathogen Parastagonospora nodorum is capable of infecting the spike, which leads to the appearance of dark brown spots on the glumes.
Triticale resistance to the disease is considered a quantitative trait, the inheritance of which depends on the parental forms. Specialized nomenclature for resistance genes, similar to that used for wheat, has not yet been developed for triticale.