EFFICACY OF MICROBIAL PREPARATIONS IN GROWING SPRING WHEAT DEPENDING ON THE FERTILIZATION BACKGROUND

Objective. Develop a fertilization system for spring wheat based on the use of effective compositions of nitrogen-fixing and phosphorus-mobilizing bacteria, which will help to reduce the spreadof disease and increase the productivity of agrocenoses. Methods. Field, measuring- and weightbased, calculation, mathematical and statistical. Results. The influence of mineral fertilizers, aftereffects of green manure, treatment of seeds with biopreparations and spraying of crops with Biocomplex-BTU on the parameters of productivity and exposure of spring wheat to powdery mildewhas been shown. It was found that pre-sowing bacterization of seeds increases yields by 3.3–12.4 %, depending on the biopreparations and fertilization background. Under the action of mineral fertilizers both separately and against the background of the after-effect of green manure, theyield increased by 31.7–41.2 %, compared with the variant without fertilizers and without inoculation. Treatment of spring wheat leaf with Biocomplex-BTU increased yield by 3.6–7.2 %, dependingon fertilizer and pre-sowing bacterization of seeds. Inoculation of seeds and treatment of crops withbiopreparations results in increase in the number and length of productive stems and grains inthe ear, although the use of fertilizers increases these parameters more significantly. Conclusion. Treatment of wheat seeds with bacterial preparations has a higher percentage efficiency in areas without fertilizers compared with fertilized ones, as well as in less favourable years for thegrowth of spring cereals, compared with more favourable. Seed inoculation with Polimiksobakterynin combination with the treatment of crops with Biocomplex-BTU, which, depending on the fertilizer, increases the crop yield by 0.54 to 0.73 t/ha, is the most effective. Crop treatment with Biocomplex-BTU significantly reduces exposure to powdery mildew.