Micromycete pathogen complex in the cultivation of garden strawberry seedlings under protected-ground conditions

In 2024–2025, the specialists of the Federal Horticultural Center for Breeding, Agrotechnology, and Nursery (Russia) conducted a series of experiments aimed at investigating the aboveground organs of garden strawberries cultivated under protected-ground conditions. The pathogen complex of plants was found to comprise the following microfungi: Alternaria spp., A. tenuissima (Kunze) Wiltshire , Botrytis cinerea Pers ., Cladosporium spp., C. cladosporioides (Fresen.) G.A.de Vries , Colletotrichum dematium Pers ., Hainesia lythri (Desm.) Höhn., Penicillium spp., Plectosphaerella spp., Podosphaera aphanis (Wallr.) U. Braun & S. Takam ., Ramularia tulashei Sacc., etc. Microfungi that affect the root system, horns, and leaf petioles included: Coniothyrium spp., Cylindrocarpon spp., Fusarium spp., F. poae (Peck) Wollenw., F. solani (Mart.) Sacc., Plectosphaerella spp., Phytophthora cactorum (Lebert & Cohn) J. Schröt., Phytophthora nicotianae Breda de Haan , Pythium spp., Rhizoctonia solani J. G. Kühn , Cylindrocarpon macrodydimum Schroers, Halleen & Crous (anamorph Dactylonectria macrodidyma (Halleen, Schroers & Crous) L. Lombard & Crous), and Ilyonectria crassa (Wollenw.) A. Cabral & Crous, Pythium spp., Phytopythium sp., R. solani. These pathogens caused root rot in strawberries grown in protected soil conditions. Wilting of strawberries in heated greenhouse conditions was mainly caused by infection with P. nicotianae oomycetes and, in rarer cases, P. cactorum and Phytopythium sp. In addition to these diseases, plants in greenhouses were often affected by the P. aphanis ascomycete, the pathogen associated with powdery mildew. When the average temperature in the greenhouse dropped to 13-15 °C and daylight hours were short in October and the first ten days of November, the aboveground parts of strawberry plants were affected by B. cinerea , the pathogen of gray mold. In protected ground conditions in the spring and autumn periods, garden strawberry seedlings showed the presence of marginal necrosis of the leaves, caused by species of the Penicillium genus.