Influence of various protection systems on the level of development of the main phytopathogens of soybean in Khabarovsk krai

The research work was carried out with the aim of determining the effectiveness of modern biological and chemical soybean protection products against pathogens of root rot and leaf and stem diseases. The work was carried out in 2016-2020, 2022-2023 in grain-soybean crop rotation in soybean crops of the Ivan Karamanov, Batya and Khabarovsky Yubilyar varieties against a natural infectious background. The main diseases in crops during the research years were root rot, septoria, and downy mildew. Pre-sowing treatment of soybean seeds can reduce the development of root rot by 1.4-2.3 times. The most effective technique in the fight against seed and soil infection in soybean crops is the treatment of seeds before sowing with chemical seed treatment agents TMTD with an application rate of 6.0 l/t, Maxim with an application rate of 2.0 l/t, Oplot and Sinclair with an application rate of 0.6 l/t, Deposit with an application rate of 1.2 l/t and Standak Top with an application rate of 1.5 l/t. The most effective protection systems against septoria were those using the complex application of Deposit with an application rate of 1.2 l/t seed treatment with Misteria with an application rate of 1.2 l/ha fungicide treatment of plants, TMTD with an application rate of 3.0 l/t with Zircon with an application rate of 40 ml/t for seed treatment with subsequent Zircon with an application rate of 10 ml/ha treatment of plants during flowering, TMTD with an application rate of 6.0 l/t (seed treatment) with Optimo with an application rate of 0.5 l/ha (plant treatment), as well as Zircon with an application rate of 40 ml/t and 10 ml/ha, Extrasol with an application rate of 2.0 l/t and 2.0 l/ha and Nutri-Fight with an application rate of 0.75 l/ha bioagents. The use of Standak Top with an application rate of 1.5 l/t as a seed treatment agent and Pictor Active with an application rate of 0.6 l/ha for treating vegetative plants reduced the incidence of downy mildew in plants by 4,6 times; TMTD for seed treatment and Optimo for spraying plants – by 3,6 times; pre-sowing TMTD with an application rate of 6.0 l/t seed treatment with subsequent Zircon with an application rate of 10 ml/ha treatment of plants during flowering – by 2,9 times, and pre-sowing seed treatment with subsequent Zircon with an application rate of 40 ml/t and 10 ml/ha treatment of plants – by 2,6 times.