Purpose. To investigate the varietal characteristics of the hemp plants for improving the quality indices of the soil they grow in, determine the amount of inorganic elements in the soil, level of their accumulation in plant stalkі and seeds. Methods. Field and spectrometric methods were basic. The results were processed using conventional methods in agriculture, crop growing and statistics. Variants of the experiment were as follows: varieties ‘Hliana’, ‘Hlesiia’: 1) soils; 2) stalks; 3) seeds. Schemes of experiments included: a) technical maturity of plants, row spacing 45 cm; b) tech­nical maturity of plants, row spacing 15 cm; c) biological maturity of plants, row spacing 45 cm; d) biological maturity of plants, row spacing 15 cm. Results. The amount of the accumulation of alkaline earth metals and their compounds by seeds and stalks of hemp plants depending on their content in vegetation soils was determined. It was found that stalks of the ‘Hlesiia’ plant accumulated strontium (Sr) and its compounds far less than that of ‘Hliana’, whereas in the seeds of the ‘Hlesiia’ variety the content of this chemical element was higher comparing with the previous variety by 70 and 78%, respectively. The difference in the accumulation of barium (Ba) compounds in seeds of hemp plants was not significant, while the tissues of the plant stalks of the ‘Hlia­na’ variety accumulated its compounds significantly more as compared to the ‘Hlesiia’ variety. The degree of influence of the variety, feeding area and the maturity stage on the processes of magnesium compounds (Mg) accumulation by plants was not revealed. Plants of the ‘Hlesiia’ variety accumulated far less calcium (Ca) and its compounds in the stalk tissues as compared to the plants of the ‘Hliana’ variety: in variants of the technical maturity stage of plants with row spacing 45 cm (a) and d – plants of narrow-row sowing (15 cm) in the biological maturity stage 30,94 and 15,95 mg/kg more in the presence in soil and in variants of the technical maturity stage of plants of narrow-row sowing (15 cm) and in the biological maturity stage with broad-sowing (45 cm) 34.54 and 24.19 mg/kg less in the presence in soil. Conclusions. The indices of accumulation of alkaline earth metals by hemp plants were significantly affected by the concentration of compounds of a certain chemical element in the arable layer, the level of energy (light) obtained by plants during vegetation, the varietal features of hemp, the stages of organogenesis of hemp plants and the specificity of their aboveground parts – stalks to accumulate these chemical elements as well as cumulate them by seeds. The varietal dependence as for accumulation of heavy metals by hemp plants tissues and seeds was established. In order to obtain environmentally friendly products, it is necessary to take into account the varietal features of plants concerning the ability to absorb and accumulate the relevant chemical elements and their compounds in the process of hemp culti­vation.

Purpose. To determine the effectiveness of using contrasting sowing dates after different predecessors to assess the genotypes of bread winter wheat in terms of yield and stability. Methods. Field, laboratory, mathematical statistics. Results. A different, but reliable level of influence on the yield of bread winter wheat genotypes of such factors as conditions of the year of cultivation (66.2%), predecessors (12.5%), sowing date (6.1%) and genotype (1.7%) was revealed. Significant differences were noted in the response of the studied genotypes to the sowing date after different predecessors. Relatively less influence of the predecessors on the yield of the varieties ‘Estafeta Myronivska’ and ‘Vezha Myronivska’ was revealed, more – for the varieties ‘MIP Darunok’, ‘MIP Kniazhna’ and ‘MIP Vyshyvanka’. The sowing dates had less influence on the yield of the varieties ‘MIP Fortuna’, ‘MIP Vyshyvanka’ and ‘Trudivnytsia Myronivska’. A general tendency for decrease in the average annual yield was established in the experiment with a shift in the sowing dates from September 26 to October 16. However, for the number of genotypes after certain predecessors, the optimal sowing date was the 5th of October: after the predecessor, green-manure fallow – for varieties ‘Trudivnytsia myronivska’, ‘MIP Assol’ and ‘MIP Dniprianka’, after mustard – ‘Vezha Myronivska’, after sunflower – ‘MIP Fortuna’, after corn – ‘MIP Fortuna’ and ‘Podolianka’. In terms of sowing dates, the least variation in yield was found after the predecessors green manure, mustard and corn varieties ‘MIP Vyshyvanka’, ‘Balada Myronivska’, ‘MIP Kniazhna’, ‘Estafeta Myronivska’. Using the GGE biplot, it was found that close to the ‘ideal environment’ for the realization of the yield level of most genotypes was the second sowing date after greenmanure fallow predecessor. For different sowing dates and predecessors, on average for three years, the optimal combination of the level of yield and stability was noted for the varieties ‘Trudivnytsia Myronivska’, ‘MIP Vidznaka’, ‘MIP Assol’, ‘Estafeta Myronivska’, ‘MIP Valensiia’. Conclusions. Thus, the use of different so wing dates after various predecessors is an effective approach to organization of genotype-environmental tests. It makes it possible to identify the genotypes which are specifically adapted to certain conditions (predecessors and sowing dates) and genotypes with a relatively high level of stability when sowing after various predecessors and on different dates. This approach can be used both at the final stage of breeding to differentiate breeding lines for yield and stability, and in the development of basic elements of technology for growing newly created varieties.