Evaluating the combined use of Kolosal Pro Fungicide and novel resistant spring wheat cultivars (Triticum aestivum L.) against Septoria Tritici Blotch and Yield enhancement

Septoria Tritici Blotch (STB) is a common disease of wheat, often occurring alongside other foliar diseases. It is known as Septoria leaf spot and is caused by the fungal pathogen Zymoseptoria tritici. STB is a major global wheat pathogen causing significant yield and quality loss. Its management is difficult due to climate variability and fungicide resistance, making an integrated approach essential. This combines using resistant hybrid cultivars with two-component systemic fungicide treatments to protect crops. This study evaluated the integrated pest management effectiveness of Kolosal Pro fungicide and identified Belyana and Agros spring wheat breeding lines (Belyana and Agros) for resistance to STB. The experiment was established from 2022 to 2024, and a wheat field experiment was conducted in Moscow, Russia. This study used a 3x3 factorial split-block design with three replications at the "Nemchinovka" Research Center. Treatments include Agros with no fungicide, Belyana with no fungicide, and integrated treatments combining Kolosal Pro with each cultivar. The application of fungicides was performed at key phenological stages (tillering, stem elongation, and flag leaf emergence), which are critical periods of effective disease management. The results indicate significant differences (p<0.05) in disease incidence, severity, and yield among treatments. The wheat lines showed considerable variation in the percentage of disease incidence and severity, which were classified as resistant and moderately resistant. The results show that Belyana x Kolosal Pro (the integrated treatment) was more resistant to STB severity (1.68%) compared to Agros and Kolosal Pro (1.70%). However, it was classified as moderately resistant. Regarding variety resistance and yield increase, the Belyana variety attained the least incidence (30.23%) and severity (1.82%) and exhibited the highest average grain yield of 4.64 t/ha. The findings demonstrated that combining the fungicide Kolosal Pro and the Belyana cultivar increases yield and reduces STB incidence and severity to an acceptable threshold level.