Biological Protection of Salanum Tuberosum L from Pathogens Using Symbiotic Bacteria Xenorhabdus Bovienii Entomopathogenic Nematodes

The results of studies conducted in 2022–2023 on the use of symbiotic bacteria Xenorhabdus bovienii entopathogenic nematodes (f. Steinernematidae) against pathogens of potato tubers (Streptomyces scabies., Rhizoctonia solani) in the conditions of the European North of Russia as a method of biological protection of potatoes are presented. Immunological assessment of tubers after harvesting showed not only a decrease in the spread of R. solani and S. scabies by 52–64 and 14–52% compared to the control, but also their development to 33–83% and 14–52%, respectively. The most effective option is double treatment with an aqueous suspension of live cultures of symbiotic bacteria X. Bovienii (EPN-1), in which the degree of development of disease symptoms on tubers decreased to 3% compared to the control (21%). The biological effectiveness of using EPN-1 for scab was 27–39%, for rhizoctonia—29–31%. The yield of potato tubers depended on the frequency of treatments and amounted to 23.53–27.78 t/ha according to the experimental options. It was greatest with double treatment of vegetative plants with EPN-2, higher than the control by 16%, respectively. Thus, significant potential for the use of biologically active secondary metabolites of Xenorhabdus sp. has been identified as biological means of protecting potato tubers from pathogens.