Sweet sorghum (Sorghum bicolor L.) is an unusual crop in Northern Kazakhstan. For its introduction in the region, seven sweet sorghum cultivars and two hybrids with a shorter vegetation period achieved cultivation and evaluation from 2020 to 2022 in the Northern Kazakhstan region. The results identified responsive genotypes to the new climatic conditions during the vegetation period. The biomass fodder values analysis referred to its chemical composition. The cultivar Volzhskoe 51 showed distinction by having a higher crude protein and fat content. Based on the acquired findings, sweet sorghum becomes highly recommendable for introduction as a fodder culture. The water-soluble sugar content determination in the central stem juice employed the refractometric method. Cultivars Kapital and Sevilia showed higher water-soluble sugars contained in the stem juice. The established fractional composition used high-performance liquid chromatography. Likewise, cultivars with a prevalent monoand disaccharide content succeeded in attaining isolation. Depending on the fractional composition, the study proposes a possible direction of sugar-sorghum juice processing for producing bioethanol and dietary food syrup. The results obtained contribute to further work on developing local sweet sorghum cultivars.
Sweet sorghum (S. bicolor L.), biomass yield, chemical composition, metabolizable energy, sugars in stem juice, silage, syrup, bioethanol
The presented study identifies the sweet sorghum (S. bicolor L.) cultivars capable of producing higher yields in Northern Kazakhstan. Biomass chemical composition and fractional analysis of stem juice show prospective use of the crop for forage, food syrups, and bioethanol.