We studied the antifungal activity of the Bacillus subtilis BZR 336g strain against the test culture of the fungus Fusarium oxysporum var. orthoceras App. et Wr. BZR 6, depending on the addition of citric acid crystalline hydrate, a microelements solution and corn extract to the liquid nutrient medium. It was found that citric acid at a concentration of 15 g/l improves the bioavailability of microelements and increases antifungal activity. Corn extract and microelements without the formation of a chelate form with citric acid do not affect the fungicidal properties of B. subtilis BZR 336g. However, the corn extract at a concentration of 3 g / l increases the titer of bacteria in the liquid culture from 2 ± 0.1 × 108 to 1 ± 0.08 × 108 CFU/ml. The combined use of the studied components allowed us to achieve a significant increase in the antifungal activity of B. subtilis BZR 336g by 3.1 times. At the same time, the effect of synergism in their complex interaction was noted, which is probably due to a qualitative and quantitative change in the composition of B. subtilis BZR 336g antifungal metabolites.

Currently, there is an active development of environmentally friendly methods of farming. However, the range of products for this type of farming system is limited. Growth stimulation is one of the mechanisms ensuring plant resistance to diseases that reduce crop yields. The aim of the work is to study the effect of laboratory samples of new biological products based on B. subtilis BZR 336 g, B. subtilis BZR 517, P. chlororaphis 245 F strains and organo-mineral fertilizers PRK White Pearl Brown (WPB) and PRK White Pearl Universal” (WPU) on plant growth and development of plants, as well as study of the possibility of their joint use for subsequent inclusion in organic farming systems or integrated plant protection. Growthpromoting ability was assessed in winter wheat and sunflower plants grown in sand in a climatic chamber. As comparison variants there were seed treatment with water (control), chemical (Dividend Star, KS) and biological (Fitosporin-M, F, B. subtilis 26 D) standards. In two plant cultures there was an expected retardant effect of the chemical standard and the growth-promoting effect of the biological standard. Statistically significant data were obtained for such a parameter as the shoot length. On winter wheat, laboratory samples provided the shoot length of 24.1-25.2 mm (an addition to the control of 3.4-8.2%), organic and mineral fertilizers - 23.9-24.5 mm (2.6-5.2%), mixtures with WPU - 23.2-24.4 mm (-0.4-4.7%), mixtures with WPB - 24.1-25.9 mm (3.4-11.2%), a significant increase in root length was not observed in this culture. On winter wheat, it is advisable to use the studied products separately. Sunflower is more responsive to the action of laboratory samples. They provided a shoot length of 13.6-14.6 mm (20.9-27.0%) and a root of 9.2-10.2 mm (4.5-15.9%). Organo-mineral fertilizers provided a shoot length of 14.2-14.5 mm (23.5-26.1%) and the root length of 10.8 mm (22.7%). Mixtures with WPU provided shoot length of 14.7-15.4 mm (27.8-33.9%), mixtures with WPB provided shoot length of 11.9-14.5 mm (3.5-26.1%), and no significant increase in root length was noted. The data obtained indicate the presence in the laboratory samples of fungicidal biological products growth-promoting properties, which vary depending on the culture and additionally used organic and mineral fertilizers. To confirm the results, additional experiments are necessary. Research in this direction will allow the rational use of the studied means of protection and increase plant yields in systems of organic, ecologized and integrated farming, and can help reduce the pesticidal pressure on agrocenoses.Conflict of interest: the authors stated that there was no conflict of interest.

Great opportunities for increasing the resource of parts of agricultural machinery that require restoration are opened up by technologies for applying hardening coatings. Options for obtaining galvanic deposits in various electrolytes, which allow depositing metal coatings with various special properties that ensure reliable operation of restored units under appropriate conditions, are considered in the article. Solutions of sulphate, chloride, and hydroboric fluoride salts of divalent iron were used as the electrolyte. Methods of chemical analysis of galvanic deposits were used. The hardness of the deposited layers was determined using a PMT-3 instrument. The effect of various alloying additives on the quality of the precipitates obtained is analyzed depending on the concentration of inclusions. The boundaries of inclusion concentrations are determined. It has been established that for controlled deposition of a composite coating, the concentration of inclusions in the deposited iron-containing coating should not exceed 20 g/l. It has been found that even an insignificant presence of manganese inclusions in an iron-based composite coating, which is of the order of the measurement error, doubles its hardness. The dependence of the concentration of ammonium chloride, as the base material for the extraction of pure manganese, on the hardness of the deposited galvanic precipitate, was studied in the framework of the described study. The highest hardness was achieved at a concentration of NH4Cl in the range of 100–150 g/l, and manganese - 0.4% by weight. Graphical dependences of the main quality indicators of the resulting coatings on the type and composition of the electrolytes used were obtained. The influence of the electrolyte temperature and electrolysis regimes on the hardness of the deposited metal is analyzed.

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