Abstract

The aim of this study was to assess the effectiveness of application of microbiological preparations based on endophytic bacteria on new potato varieties under different soil and climatic conditions in Russia. Altogether, 194 strains of endophytic bacteria were isolated from the tubers of wild type potato and the tubers of cv. Sudarynya, and two promising strains viz. Paenibacillus xylanexedens N40 and Bacillus thuringiensis W65 were chosen. Field microplot trials with new potato varieties in Novosibirsk region showed that the treatment of plants with new microbiological preparations had a positive effect on the potato yield gain. The greatest gain was obtained when the preparation based on P. xylanexedens N40 was used on cv. Reggi and when the preparation based on B. thuringiensis W65 was used on cv. Tango. In field microplot trials in the Leningrad region the potato yield increased significantly after the application of microbiological preparations by 10.9-12.2% in case of cv. Kalibr and by 19.0-24.2% in case of cv. Rozovyi Charodei. The application of microbiological preparations based on endophytic bacteria P. xylanexedens N40 and B. thuringiensis W65 considerably decreased the prevalence of phytophthorosis on tubers of cv. Kalibr and the prevalence of fusariosis and common potato scab on tubers of cv. Rozovyi Charodei.