Agrobiological parameters of various varieties and hybrids of sweet sorghum

Purpose. To reveal the features of agrobiological parameters formation of sweet sorghum various varieties and hybrids in the conditions of the Right-Bank Forest-Steppe of Ukraine. Methods. During 2018–2020 twenty-one varieties and hybrids of sweet sorghum of various ecological and geographical origins (Ukraine, Russia, USA, France, Germany, Hungary, Brazil) were studied in the field. Parameters like plant height and indices of their individual productivity (grain weight per panicle, 1000 grain weight, etc.), yield of dry biomass and grain, content of sugar in juice and protein in grain, as well as estimated sugar and protein yield in a crop. The counts were carried out in the phase of physiological ripeness of the culture. Results. In the group of Ukrainian varieties and hybrids, the plants were from 272 to 306 cm high, in the foreign group – from 274 to 412 cm. Varieties ‘Red Amber’, ‘Sioux’, ‘Affas CJ 899’, ‘Freed’ and ‘Early Orange’ are of high value for breeding practice, their plants were the tallest – from 388 to 412 cm. The panicle length of sweet sorghum cultivars of Ukrainian breeding ranged from 16.0 to 17.3 cm, foreign – from 11.0 to 19.4 cm. Grain weight from one panicle varied from 32.8 to 41.6 g and from 29.2 to 43.5 g, respectively. In a wide range, depending on the varietal characteristics, the indicator of the number of grains per panicle also varied from 1338 to 1708 pcs. The mass of 1000 grains of sweet sorghum ranged from 28.0 to 31.0 g in varieties and hybrids of Ukrainian breeding, in foreign ones – from 19.3 to 31.0 g. The yield of dry vegetative mass of cultivars of Ukrainian breeding was at the level of 8.24–9.11 t/ha. The highest rates were shown in hybrid ‘Mamont’ and ‘Huliver’ variety – 9.05 and 9.11 t/ha, respectively. For cultivars and hybrids of foreign breeding, this indicator varied from 7.00 to 12.17 t/ha. Significantly higher biomass in comparison with the standard variety (‘Sylosne 42’) was produced by ‘Vorai Sumac’, ‘Sorgo Cucre’, ‘Sioux’, ‘Freed’, ‘Red Amber’, ‘Mohavk’, ‘Affas CJ 899’, ‘Early Orange’ – 9.03–12.17 t/ha. The sugar content in sweet sorghum juice varied from 15.2 to 17.2%. The estimated sugar yield in Ukrainian cultivars was at the level of 0.82–0.89 t/ha, in foreign ones – from 0.72 to 1.18 t/ha. In all studied varieties it was the highest in ‘Sorgo Cucre’, ‘Sioux’, ‘Freed’, ‘Red Amber’, ‘Mohavk’, ‘Affas CJ 899’, ‘Early Orange’ – 0.94–1.18 t/ha. Conclusions. The productivity of sweet sorghum varies greatly depending on the origin of the variety and hybrid. In the conditions of the Right-Bank Forest-Steppe, in order to obtain a high sugar yield, it is advisable to grow ‘Sylosne 42’, ‘Favoryt’, ‘Troistyi’, ‘Dovista’, ‘Huliver’ varieties and ‘Ananas’, ‘Medovyi’, ‘Mamont’ hybrids. Varieties ‘Vaconia Orange’, ‘Vorai Sumac’, ‘Sorgo Cucre’ and hybrids ‘Ald Sorghum’, ‘Sioux’, ‘Freed’, ‘Red Amber’, ‘Mohavk’, ‘Affas CJ 899’, ‘Early Orange’ provide high yields of vegetative masses. Hybrids ‘Freed’, ‘Affas CJ 899’ and ‘Early Orange’ produce a large vegetative mass (11.08–12.17 t/ha), grain yield (8.00–8.15 t/ha) and a high protein content (9.8–11.3%).