PREVALENCE OF CAUSATIVE AGENTS OF RING ROT CLAVIBACTER SEPEDONICUS, BLACKLEG AND WET ROT PECTOBACTERIUM ATROCEPTICUM IN THE 2021 YEAR POTATO HARVEST IN THE TERRITORY OF UKRAINE

Aim. To investigate the prevalence of causative agents of ring rot and soft rot in the potato harvest by the DAS ELISA method. Materials and methods. Samples of the potato harvest from Ternopil, Zhytomyr, Kyiv, Cherkasy, Dnipropetrovsk, Donetsk, Mykolaiv, Odesa, and Kherson regions were used in the study. The detection of bacterial agents was conducted by enzyme-linked immunosorbent assay using commercial test systems LOEWE® Standard Complete Kit (Germany). Results. The highest percentage of affected potatoes was registered in the Donetsk region: 11.1% – by the Clavibacter seedonicus, 31.0% – by the Pectobacterium atrosepticum, and 8.9% – by both bacteria. The causative agent of soft rot was detected twice as often as a causative agent of ring rot in tuber samples from all regions, except the Ternopil region, where the predominance of Clavibacter sepedonicus was revealed. In addition to the Donetsk region, a high prevalence of the causative agent of soft rot was found in the potato harvest from Kyiv (10.2%) and Odesa (10.0%) regions, the highest abundance of the causative agent of ring rot was detected in the Ternopil region. The mixed bacterial infection of potato tubers was diagnosed in 6 areas, and the highest rate was detected in the Donetsk region. Conclusion. The analysis of the distribution of ring rot pathogen Clavibacter sepedonicus and soft rot pathogen Pectobacterium atrocepticum in the potato crop shows the presence of research pathogens in all studied regions. It was discovered the dominance of the representative of pectolytic bacteria in all regions except Ternopil, where the distribution of Clavibacter sepedonicus, the causative agent of ring rot, was dominated. High rates of spread of the studied pathogens were associated with increased local average annual precipitation, as well as with increased annual amplitude of this indicator.