Annotation

The results of the research show that the main diseases of soybeans, the causative agents of which are developed on plants during the growing season, included the diseases of fungal etiology. The most common are: downy mildew, Septoria spot, Cercospora spot, Ascochyta spot, powdery mildew, and Fusarium wilt and root rot.

The use of fungicide Aliette, 80 % WG (fosetyl present as aluminium salt 800 g/kg) at the beginning of the budding phase (BBH 49–51) and one of preparations Coronet, 30 % SC (trifloxystrobin 100 g/l + tebuconazole 200 g/l) used with adjuvant Mero or Propulse, 25 % SE (fluopyram, 125 g/l + prothioconazole, 125 g/l) or Fox, 32.5 % SC (trifloxystrobin, 150 g/l + prothioconazole, 175 g/l) at the beginning of bean formation (BBH 69–71) effectively limit the progress of plant damage.

The development of major diseases on the variants of the experiment with fungicides did not exceed 5 %. The effectiveness of the investigated schemes of spraying soybean plants exceeded 80 % against the causative agents of Septoria spot, Cercospora spot and Fusarium wilt and root rot, 78 % against the causative agents of downy mildew, and ascochitosis and 65 % against the causative agent of powdery mildew. The highest efficiency of action was provided by the variant of the experiment, where the fungicides Aliette, 80 % WG and Propulse, 25 % SE were alternately introduced. All the soybean spraying schemes under study provided a significant yield supplement comparing to the control. The indicators of weight of 1000 seeds on the variants with the preparations were by 15–20 g higher as compared to the control. The highest yield of 37.5 c/ha, which was 11.0 c/ha in addition to the control, was provided by the variant with the Aliette, 80 % WG – 1.5 kg/ha, Propulse, 25 % SE – 0.8 l/ha.

To secure effective protection of soybean plants during the growing season from the main diseases, it is proposed to use for the first application at the beginning of budding in the ВВСН 49–51 phase 49–51 fungicide Aliette, 80 % WG (fosetyl present as aluminium salt 800 g/kg) at a rate of 1.5 kg/ha, for the second – at the beginning of the formation of beans in the phase BBH 69-71 the preparation Propulse, 25 % SE (fluopyram, 125 g/l + prothioconazole, 125 g/l) – 0.8 l/ha.