The dissertation presents the results of research and theoretical justification for improving the elements of grain sorghum cultivation technology: studying varietal characteristics, the influence of different rates of mineral fertilizers, and seeding rates on plant growth and development, productivity, yield, and its quality indicators. Domestic and foreign scientific works on the significance of the crop in the global market and issues of grain sorghum cultivation in the world, Ukraine, and Sumy region, which show a positive trend towards an increase in sowing areas and crop yields in recent years, have been analyzed. An overview of studies on the impact of different rates of mineral fertilizers and seeding rates on the growth processes of grain sorghum plants, morphometric parameters, and quality indicators of plants has been provided. It was determined that the field germination of sorghum in the experiment was influenced by the seeding rate, weather conditions of the year, and genotype characteristics: the highest values of the indicator over the years of research were noted in the variant with a seeding rate of 165 thousand units/ha for the Yankee hybrid (88.9%), while the Samaran 6 and Dniprovskyi 32 varieties were 6.3–6.6% lower. With an increase in the seeding rate, a trend towards a decrease in field germination was observed in all sorghum varieties and hybrids, namely: Yankee – up to 15%, Dniprovskyi 32 – up to 13%, Samaran 6 – up to 9.9%. Among the agronomic factors studied, the seeding rate had the greatest impact on field germination – 66%, with genetic characteristics of the varieties and hybrids accounting for 15%. The survival rate of the grain sorghum varieties and hybrids depended on the seeding rate, being highest in the variants with the lowest seeding rate in the experiment – 165 thousand units/ha and amounted to 70.8–77.8% depending on the variety. The preharvest plant density was highest in the experiment in the variant with the highest seeding rate – 490 thousand units/ha for all varieties and hybrids, averaging 299.43 thousand plants/ha. A difference was found between the variants in the formation of generative organs of the plants. The number of panicles in sorghum plants depended on both the application of fertilizers and the variety characteristics and was highest in the Yankee hybrid at 226.77 thousand/ha and in the Samaran 6 variety at 254.81 thousand/ha. The N35P35K35 and N70P70K70 fertilizer rates provided the highest values: 238.11 and 255.92 thousand/ha, respectively. The maximum values of the inflorescence length parameter were in the variant with the application of mineral fertilizers at the rate of N70P70K70. In the variants with the application of N16P16K16 and N70P70K70 fertilizers, a trend towards a decrease in panicle size was observed. The highest number of seeds per panicle was in the Yankee hybrid (831.72 seeds/panicle) and in the Dniprovskyi 39 variety (518.98 seeds/panicle), with the application of N35P35K35 and N70P70K70 fertilizer rates providing 575. and 666.85 seeds/panicle, respectively. It was found that the seed mass increased with higher doses of fertilizers in the experimental variants. The highest mass of 1000 seeds was in the Yankee hybrid (20.65 g) and the Dniprovskyi 39 variety (14.68 g). For the formation of filled seeds, the optimal fertilizer rates were N70P70K70 and N35P35K35 – 26.68 and 25.15 g, respectively. It was established that in the Dniprovskyi 39 variety, the highest profit and level of profitability were ensured by the application of the N35P35K35 fertilizer rate – 709 UAH/ha and 3.8%, respectively. Positive values were achieved in the variant with the N70P70K70 fertilizer rate: profit – 411 UAH/ha, profitability – 1.7%. All fertilizer application rates in the cultivation of the Yankee hybrid ensured positive profitability and returns. The maximum profit in the variant with the N70P70K70 fertilizer rate was 10570 UAH/ha, with a profitability of 43.7% in this variant.
