PHYTOPATHOGENIC COMPLEX STRUCTURE OF RADISH UNDER OPEN-GROUND CULTIVATION IN THE RIGHT-BANK FOREST-STEPPE OF UKRAINE

Abstract

The features of the phytopathogenic background formation in radish crops under open-ground cultivation in the territory of the Right-Bank Forest-Steppe of Ukraine for the years 2008–2022 were analyzed. It was determined that the phytosanitary condition of radish crops is environmentally hazardous and requires strict control of disease agents. A total of 48 species of phytopathogens were identified on plants, including 4 species of viruses, 11 species of bacteria, 25 species of fungi, and 8 species of oomycetes, causing 24 types of diseases. Accordingly, in the structure of the phytopathogenic complex, fungi occupied — 52%, bacteria — 23%, oomycetes — 17%, viruses — 8%. Pathogens causing damping-off (Phytophthora spp., Fusarium spp., Pythium debaryanu, Rhizoctonia solani), fusariosis (Fusarium avenaceum, F. graminearum, F. moniliforme Schw., F. oxysporum f. sp. raphani), and phomosis (Phoma exigna, P. lingam (Tode) Desm.) were identified with high frequency in radish crops. Among the identified phytopathogens, seven species were recognized as the most dangerous worldwide: Cucumber mosaic virus, Tomato spotted wilt virus, Ralstonia solanacearum, Botrytis cinerea Fr., Fusarium graminearum, Fusarium oxysporum, Albugo candida. The dominant diseases of radish during 2008–2022 were downy mildew and powdery mildew, affecting an average of 5–16% (max 20%) of the crop area. The most widespread diseases on plants were powdery mildew (21–30%), downy mildew (18–28%), various types of rots (15–26%), bacterial leaf spot (18–22%), and fusariosis (15–23%), with symptoms appearing at almost all stages of radish plant organogenesis. Critical stages were found to be the initial phases (BBCH 0–9, BBCH 10–11) and the period of root formation and growth (BBCH 41, BBCH 42–48).