Improving the spring wheat protection system through monitoring the dynamics of leaf and stem mycoses and application of biological preparations in the Republic of Tatarstan, Russia

Abstract

Introduction. In the context of increasing fungicide resistance and climate change, the development of biological methods for protecting spring wheat against leaf and stem mycoses is becoming particularly relevant for agricultural regions of Russia. Although chemical fungicides dominate current protection systems, their efficacy is declining due to the development of pathogen resistance. Furthermore, regional specifics of pathogenic complex formation and the effectiveness of combined biopreparations based on endophytic bacteria with organic acids for specific agroclimatic zones remain insufficiently studied.
Aim. To investigate the long-term dynamics of leaf and stem mycoses development in spring wheat and to evaluate the biological efficacy of biopreparations based on strains Bacillus mojavensis PS17 and Bacillus amyloliquefaciens KS-25 AU in combination with organic acids in the conditions of the Predkamye region of the Republic of Tatarstan.
Materials and methods. Phytopathological survey data from 2002-2025 were used to assess mycoses dynamics. On the Ulyanovskaya 105 variety, seed treatment and spraying with a biopreparation based on Bacillus mojavensis PS17 at different application rates were studied. On the Ekada 214 variety, the application of experimental biopreparations based on Bacillus amyloliquefaciens KS-25 AU and various organic acids (ascorbic and succinic) was evaluated.
Results. Leaf septoria was identified as the dominant disease in the pathogenic complex, exceeding the economic damage threshold during the observation period. The highest efficacy in disease control was achieved using Bacillus mojavensis PS17 according to the scheme 1.0 L/t (seed treatment) + 1.0 L/ha (spraying): reduction of septoria development by 68.6% and a yield increase of 9.2%. Compositions based on Bacillus amyloliquefaciens KS-25 AU with organic acids, when applied twice, ensured a reduction in disease development by 32-77% and an increase in yield by 11.9-13.3%.
Conclusion. The work demonstrates high efficacy of biopreparations based on the studied strains of endophytic bacteria in combination with organic acids for the conditions of the Predkamye region of the Republic of Tatarstan. The results allow recommending these developments for practical use in regional spring wheat protection systems as an environmentally safe alternative to chemical fungicides.

To cite: Abramova A.A., Vafin I.Kh., Medvedev N.A., Safin R.I. Improving the spring wheat protection system through monitoring the dynamics of leaf and stem mycoses and application of biological preparations in the Republic of Tatarstan, Russia. Agrarian Bulletin of the North Caucasus. 2025;15(4):57-68. https://doi.org/10.31279/2949-4796-2025-15-4-57-68