Biological effectiveness of the Bt 26 strain of Bacillus thuringiensis in fighting the root-knot nematode Meloidogyne inсognita

Plant-parasitic nematodes pose a great threat to v arious crops, killing them and causing damage to agriculture. The bacteria-based approach to fighting them seems particularly promising, as it also makes it possible to lower the use of chemicals and reduce the effects caused by environmental changes. The goal of this work is to study the biological effect of the bacterium Bacillus thuringiensis against nematodes from the genus Meloidogyne . Samples of cucumbers from an experimental site deliberately infected with the southern root-nematode Meloidogyne incognita were used as material for this work. The study was conducted in 2023 – 2024. Phytohelmintology and microbiology methods were used in the research. In vivo experiments and studies in greenhouses and in the field have shown that bacteria can help regulate in various ways the development of endoparasitic nematodes. In conclusion, as a result of our studies of the local bacterial strain Bt 26, which has high nematocidal activity against M . incognita , we determined the optimal schemes of application of the bioprepar a tion. Application of seed encapsulation with Bt.-26 strain bacteria further increased the efficiency of microbial agents. Seed treatment with Bt.-26 contained the lowest galling index of 0.5. Treatment with bacteria, which initiates protective mechanisms in plants, is regarded as an optimal solution, since it is no less or even more effective than the use of chemical pesticides. Moreover, bacteria have additional positive effects on plants, such as growth stimulation, which increases their productivity.