Ecological interactions in the system: Entomopathogenic bacterium Bacillus thuringiensis—phytopathogenic fungus Rhizoctonia solani—host plant Solanum tuberosum

The mutual functional dependence in the three-component system Bacillus thuringiensis-Rhizoctonia solani–Solanum tuberosum is shown. Suppression of the rhizoctonia potato disease due to the treatment of tubers with entomopathogenic bacteria Bacillus thuringiensis subsp. Darmstadiensis (BtH 10) is demonstrated. In vitro inhibitory activity of BtH 10 towards R. solani exceeded 80%. Field testing is carried out on two potato cultivars of different ripeness groups in 2013–2014. The rhizoctonia disease severity in stems, stolons, and new tubers decreases significantly due to BtH 10 treatment. Together with biological control of R. solani, BtH 10 promoted plant growth, increasing germinating capacity and stem height and number. The polyfunctional activity of the BtH 10 bacteria contributes to the improvement of potato productivity.