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The effectiveness of chemical, fungal and bacterial fungicide treatments of spring soft wheat seeds and stands against major diseases was compared on leached chernozem of Novosibirsk region in 2021. Biological preparations including Sternifag, WP (Trichoderma harzianum) showed effect as early as in the tillering phase. The biologicals’ effectiveness in root rot suppression was comparable to Scarlet, ME (imazalil+tebuconazole) and amounted to 62–64 %, while Sternifag, WP halved the disease development. By the end of the growing season, all treatments, including the chemical one, equally suppressed root rot development; the best option was Scarlet, ME + Vitaplan, WP (Bacillus subtilis) with biological efficiency of 38 %. In the case of severe pressure by Septoria blotch (33 % in control), the most effective treatment was spraying the crop on the earing stage with Titul 390, KKR (propiconazole), which reduced the incidence of Septoria blotch by 84.3 %, while biologicals had no effect. The powdery mildew was best suppressed by seed treatment with Scarlet, ME (73.9 %), and the brown rust was best suppressed by Scarlet, ME + Vitaplan, WP (78.8 %). The vegetation treatments inhibited the powdery mildew by 41–54 % but didn’t show a reliable effect against the brown rust. Seed treatment with microbial fungicides increased soil cellulolytic activity by 1.5–1.8 times while chemical disinfectant reduced it. The amount of plant residues decreased by 2.5–2.8 times due to the application of Sternifag, WP. The greatest increase in grain yield was obtained due to chemical fungicides - 0.64 t/ha, while biological preparations resulted in additional 0.25–0.33 t/ha.

The paper presents data on a comparative test of the efficacy of chemical, fungal and bacterial fungicides in limiting the harmfulness of main diseases of spring wheat. The research was carried out on leached chernozem of the forest-steppe of Priobye of the Novosibirsk region. It was shown that Sternifag, SP reduces the development of root rot at the end of the growing season by 48 %, which is comparable to the effect of a chemical dressing agent Scarlet, ME (imazalil+tebuconazole) and is slightly inferior to the action of combined application of fungal preparation Trichocin, SP with the bacterial preparation Vitaplan, SP (55 %). Preplanting seed treatment effectively reduced the development of leaf infections: Scarlet, ME suppressed the development of Septoria blotch by 54 %, Scarlet, ME + Vitaplan, SP – of powdery mildew by 69 %, Trichotsin,SP + Vitaplan, SP – of brown rust by 74 %. Fungicide Titul 390, KKR reduced the development of these diseases by 60, 81 and 85 %, respectively. Alirin-B, W with Trichocin, SP suppressed brown rust by 64 %. Cellulolytic activity increased 1.3–1.9 times compared to the control as a result of the action of biological products and Sternifag, SP. The amount of plant residues decreased 2.4 and 1.9 times 15 and 30 days after application. The greatest increase in yield was provided by chemical fungicides – 0.7 t / ha, they were not inferior to the use of Alirin-B, W with Vitaplan, SP against the background of etching with Scarlet, ME fungicide.

Russian soft wheat varieties are screened with the use of molecular markers of Lr genes. A low genetic diversity is found among leaf rust resistant varieties, in which genes Lr9 and Lr19 dominate. There are no highly effective genes Lr25, Lr29, and Lr39(41) and adult plant resistance genes Lr37 and Lr21 in the studied varieties. Among genes with limited effectiveness, the most prevalent are genes Lr10 and Lr26, respectively in 45 and 10% of the varieties.