Assessment of genetic parameters and yield trait stability in sweet sorghum genotypes through AMMI and GGE biplot approaches

Biofuel from sweet sorghum is an alternative and viable source of renewable energy. This study was conducted to determine the interaction between genotype and environment on yield traits, assess stability and identify the most suitable sweet sorghum genotypes for biofuel production. Genotypes comprised of 80 sorghums (Sorghum bicolor (L.) Moench) genotypes (63 sweet sorghum genotypes, 12 improved grain sorghum and 5 sweet sorghum landraces) grown in four environments in the Sudano–Sahelian region of Nigeria. The combined analysis of variance of the sweet sorghum genotypes in two years (2018 and 2019) over the two environments revealed that year(Y), genotype(G), environment(E) and genotype by environment interaction (G × E) were significant in the entire biofuel yield attributes except the Brix at maturity and bagasse. AMMI analysis of variance effects of G, E, and G × E. These significant effects of G, E, and G × E were used to identify the best-performing, most adaptable and most stable genotypes. Genotype contributed 77.2% of the total sum of squares for Brix, followed by environment (1.37%) and interaction (0.47%). For grain yield, environmental effects accounted for 89.5% of the total sum of squares, whilst genotype and interaction accounted for 3.6% and 1.1% respectively. Genotypic variances for stalk fresh yield are 5.5% and those for environment and interaction are 88.3% and 0.8%, respectively. The total sum of squares of the environment for juice volume is 39.5%, with genotype contributing 32.4%, and the interaction contributing 4.2%. Environment and interaction contribute to bagasse are 82.6% and 1.4% respectively, and that of genotypes is 7.1%. This suggests a better chance of progress in the genetic improvement of these traits. The genotype SEREDO, SPV 422-NB, IESV 92008 DL, ICSB 324 and F7.5SSM09-5-3/3-2-2-2 combined high yields with stability in grain, juice, stover, bagasse and Brix, respectively, according to the stability index ranking across environments. On the other hand, genotypes SERENA-ML and Gwaram, though high-yielding, were unstable according to AMMI stability value scores.