The dissertation provides a theoretical generalization and substantiates a new approach to the fulfillment of a scientific task - optimization of the elements of grain sorghum cultivation technology.
A comprehensive assessment was conducted to identify the features of crop formation by sorghum hybrids; the optimal growth regulator is determined; a microfertilizer was identified, which helps to increase the productivity of grain sorghum plants. Effective technological approaches in the cultivation of grain sorghum through the introduction of promising hybrids and the introduction of microfertilizers and plant growth regulators have been identified.
The research vectors of the peculiarities of the growth processes of grain sorghum plants, the formation of the leaf surface area, and the assessment of economic and energy efficiency have gained further development.
Weather conditions during the research period were favorable for the growth and development of grain sorghum, although they differed from the average perennial units.
The conducted studies showed that the duration of the vegetation period in the Brigg hybrid is 104-107 days, and in the Yutami hybrid – 114-115 days, and it corresponded to the specified varietal characteristics. It is worth noting that the influence of the researched technology factors was significantly manifested only during the period of active growth of sorghum. Thus, in the Brigg hybrid, the application of Alpha-Grow-Extra feeding at a dose of 2 l/ha and the treatment of Intermag - Maize plants at the same dose led to an increase in the duration of the interphase period by 2 days.
In the Yutami hybrid, the use of Alfa-Grow-Extra feeding at a dose of 2 l/ha also increased the duration of the interphase period, but already by 3 days, while the treatment of Intermag plants - Kukurudza, 2 l/ha - led to an increase in this period by 2 days. Therefore, it can be stated that the researched technology factors have a sufficient influence on the duration of the interphase period of sorghum of various hybrids.
In the hybrid sorghum Brigg, the density of crops was higher in the areas where treatment with foliar microfertilizer Intermag - Kukurudza, 2 l/ha, in combination with the growth regulator Regoplant was used, and reached 152.8 thousand pieces/ha, and the survival of plants during the growing season was 94.0 %. In the Yutami hybrid, a higher level of preservation of crop density was achieved with the help of foliar feeding of Alpha-Grow-Extra, 2 l/ha, together with the growth regulator Regoplant, and reached 152.6 thousand pieces/ha, and the survival of plants during the growing season was 94.6 %. It is also worth noting that when using foliar fertilization Intermag - Kukurudza, 2 l/ha, the optimal option for the Yutami hybrid was the combination with the growth regulator Stimpo, since the density of crops remained at the level of 152.4 thousand pcs./ha, and the survival of plants during the growing season was 94.1%. So, as a result of the experiment, the optimal options for maintaining the density of crops and plant survival for the Brigga and Yutami hybrids using various combinations of microfertilizers and growth regulators were determined.
The conducted studies showed that the elements of the technology we used influenced the formation of the height of sorghum plants only at the stages of panicle ejection and flowering. However, by the end of the growing season, in particular at the time of full maturity, the average height of the plants in the experiment was 117.3 cm. It turned out that the use of additional elements of growing technology did not significantly affect the studied indicator at the late stages of growing season. In the study of the Brigg hybrid, the plant height was in the range of 118.5-124.1 cm, and in the Yutami hybrid - from 111.7 to 117.2 cm. Thus, it can be concluded that although some elements of technology influenced the formation of plant height at certain stages of development, this influence was insignificant in the later stages of vegetation.
In the phase of panicle ejection, it was found that the Brigga hybrid showed the best indicators of leaf area under foliar fertilization with microfertilizer Intermag - Kukurudza, in combination with the growth regulator Regoplant, which was 49.1 thousand m2/ha. In the Yutami hybrid, higher values of the leaf surface area were noted when using Intermag - Kukurudza in combination with Regoplant or Stimpo, reaching 52.9 thousand m2/ha. At the same time, on the control variant without the use of additional growth regulators, the following values of the leaf area were found - 48.1 thousand m2/ha. In the flowering phase, higher indicators of the leaf surface area were also observed with foliar treatment with microfertilizer Intermag - Kukurudza, 2 l/ha. In this case, the influence of growth regulators was insignificant.
