Yield formation and energy potential of Sorghum saccharatum (L.) Moench biomass under the conditions of the central Ukrainian Forest-Steppe

Abstract

Purpose. Study of the dynamics of formation of biometric indicators, biomass yield and energy potential of sorghum varieties in the conditions of the Central ForestSteppe of Ukraine. Methods. Field, laboratory and statistical methods were used. Five registered varieties of sorghum, viz: ‘Huliver’, ‘Dovista’, ‘Zubr’, ‘Su’ and ‘Tsukrove’ served as the object of research. The measurement of biometric indicators of plants, the calculation of biomass yield and energy potential were carried out in accordance with approved scientific and methodological recommendations. Results. The most rapid growth in height of sorghum was observed during the interphases of “seedling – leaf-tube formation and leaf-tube formation – flowering”. At the end of the growing season, plants of the varieties ‘Huliver’ (237.2–245.1 cm), ‘Tsukrove’ (218.0–227.2 cm) and ‘Dovista’ (205.6–220.9 cm) were the tallest. ‘Hulliver’, ‘Tsukrove’ and ‘Zubr’ were characterized by the largest photosynthetic leaf area, they produced the largest biomass and were characterized by the highest energy efficiency of cultivation in terms of energy productivity (EPс equal to or greater than 60.0 GJ/ha) and energy efficiency coefficient (Kee equal to or greater than 4.0). Conclusions. The highest biomass yield by dry residue was found in the sorghum varieties ‘Huliver’ (15.4 t/ha), ‘Tsukrove’ (15.2 t/ha) and ‘Zubr’ (12.5 t/ha). The same varieties were characterized by high energy productivity (the difference between the energy stored in biomass and the energy used to produce it) – 65.3, 64.9 and 56.8 GJ/ha respectively, with a Kee value of 4.0 or more, which characterizes the average level of biomass production efficiency.