Bioethanol yield from stems of different sugar sorghum hybrids at different sowing rates

Abstract

Aim. To determine bioethanol yield from sugar sorghum stems at different plant sowing rates. Methods. Field – establishing and conducting research, physical – determining the yield of plant vegetative mass, chemical – determining stem sugar content, analysis and statistical. Results. The article presents the study results of the yield of vegetative and dry mass, stem sugar content, bioethanol yield for the cultivation of various hybrids of sugar sorghum with a sowing rate of 75, 100, 150 and 200 thousand psc/ha. It was found that in the variant with the highest sowing rate, the green mass yield of Mamont, Verbliud and Sokhatyii hybrids increased to 82.9–92.6 t/ha, and that of Zubr, Favoryt and Medovyi ones increased to 72.6–78.6 t/ha. The highest yield of dry mass was obtained at a density of 200 thousand pcs/ha in Zubr and Mamont hybrids – 19.3–20.0 t/ha. The yield of dry mass at the level of 14.0–17.5 t/ha was obtained for the cultivation of Favoryt, Medovyi, Verblid and Sokhatyii hybrids with a sowing rate of 150–200 thousand pcs/ha. The highest yield at sowing rates of 75 thousand pcs/ha was provided by the cultivation of Mamont, Verbluid and Sokhatyi hybrids – 12.4–13.7 t/ha. It was found that stem sugar content decreased significantly with the increase in plant sowing rate. In addition, in the stems of Zubr and Verb­luid hybrids, sugar content was significantly higher compared to other hybrids - 17.0–18.9%, depending on sowing rate. The highest bioethanol yield was provided by the cultivation of Zubr, Mamont, Verbluid and Sokhatyi hybrids with a sowing rate of 200 thousand pcs/ha – 6 467–7 215 l/ha. At this sowing rate, the bioethanol yield in other hybrids was at the level of 5563–5658 l/ha. In addition, stability index varied from 0.31 to 0.88. Conclusions. In the conditions of the Right Bank Forest Steppe, bioethanol yield from sugar sorghum stems varies depending on the hybrid and plant sowing rate. Under the growing conditions of Zubr, Mamont, Verbluid and Sokhatyi hybrids with a sowing rate of 200 thousand units/ha, bioethanol yield is 6467–7215 l/ha. In addition, biothenol yield is affected by weather conditions. In more favorable weather conditions, this indicator is 8.508–9.149 l/ha in Zubr, Mamont, Verbluid, and Sokhatyi hybrids with a sowing rate of 200 thousand pcs/ha, and in less favorable conditions, it is 3.784–5.922 l/ha or less by 1.4–2.4 times.