Krasnoshtan V. Scientific substantiation of chemical and biologic preparates use in grain sorghum crops in the Right-Bank Forest-Steppe of Ukraine

The following were used for the research: grain sorghum (Sorghum bicolor (L.) Moench) hybrid Milo W, herbicide Cytadel 25 OD, plant growth regulator Endophit L1 and biological preparation Bioarsenal. According to the results of vegetation studies, the influence of different doses of the herbicide Cytadel 25 OD (0,6–1,0 l/ha), the plant growth regulator Endophit L1 (30 ml/ha), and the biological preparation Bioarsenal (800 g/100 kg) on the passage of lipid peroxidation reactions in grain sorghum plants was established. In the course of research, it was established that the content of chlorophylls a, b, their sum (a+b) and carotenoids in the leaves of grain sorghum depended on the rates of the herbicide application and on the methods of combining it with the plant growth regulator and the biological preparation. The content of carotenoids in the leaves of grain sorghum, as well as chlorophylls, was the highest at the integrated use of the studied preparations and exceeded the control in the stage of panicle ejection of the culture by 34.0–38.4% on average over the years of research. The results of the conducted research indicate that the indicator of the net photosynthetic productivity of grain sorghum was significantly influenced by both, weather conditions and methods of use of the studied preparations. It was established that the use of the studied preparations had a significant effect on the abundance of certain ecological-trophic groups of microorganisms in the rhizosphere of grain sorghum. The results of weeds accounting in grain sorghum crops showed that the level of weeding in the crops depended on weather conditions and the use of different rates of the herbicide Cytadel 25 OD, the plant growth regulator Endophit L1 and the biological preparation Bioarsenal. The highest yield of grain sorghum, on average over the years of research, was demonstrated by variants where the herbicide Cytadel 25 OD at rates of 0.6; 0.8 and 1.0 l/ha was used in mixtures with the plant growth regulator Endophit L1 (30 ml/ha) and on the background of pre-sowing seed treatment with the biological preparation Bioarsenal (800 g/100 kg). It was established that the highest indicators of the economic efficiency of cultivating the grain sorghum were formed in the variant of complex application of the herbicide Cytadel 25 OD at the rate of 1.0 l/ha, the plant growth regulator Endophit L1 (30 ml/ha) on the background of pre-sowing seed treatment with the biological preparation Bioarsenal (800 g/ 100 kg), which provided an additional net profit at the level of UAH 4,559 at a profitability level of 67% and an energy efficiency ratio of 4.3. For effective control of weeds and activation of a number of physiological and biochemical processes in plants, which allow to achieve high productivity, it is advisable to use the herbicide Cytadel 25 OD (0.6–1.0 l/ha) at the rate of 1.0 l/ha compatibly with the plant growth regulator Endophit L1 (30 ml/ha) on the background of pre-sowing seed treatment with Bioarsenal (800 g/100 kg).