In the pathocomplex of any agricultural crop, there are different micromycetes, the composition of which varies depending on weather and climatic conditions, seasonal changes. The fungus A. dauci (J. G. Kühn) Groves et Skolko is one of the most harmful pathogens on table carrots, affecting leaves, petioles, and stems. A. radicina Meier, Drechsler et E. D. Eddy damages carrot root crops during storage, causing a hard rot, coal-black, sharply delimited from healthy tissue.
 These pathogens occur everywhere and simultaneously; n addition, the optimal conditions for the development of both pathogens are similar. Yield losses from Аlternariа can reach 40–99 %. The complex of fungal species of the genus Fusarium is a ubiquitous soil pathogen of agricultural crops with a wide phylogenetic and ontogenetic specialization, which causes destructive vascular wilting, rot, and necrosis.
 The most common are F. oxysporum and F. avenaceum, the latter can also exist as a saprotroph. As a result of the work done, the released mycelium for drawing up the palette is described. It was revealed that the colonies of fungi with light-colored mycelium (54.8%) were larger in the samples from the Voronezh region, which were based on species of the genus Fusarium. In the Moscow region with sufficient moisture, isolates of fungi with light-colored mycelium slightly dominated (43.7 %). In the Rostov region, the frequency of occurrence of isolates of fungi with dark-colored mycelium was on average 58.1%, dominated by fungi of the genus Alternaria.