Genotype × environment interaction and spatial analysis of sorghum[Sorghum bicolor(l.) moench] genotypes in the highland areas of Ethiopia

Sorghum plays a critical role in ensuring global food security, particularly in regions where both abiotic and biotic stresses severely affecting sorghum production. However, genotype × environment (G × E) interaction and spatial variation remain central problem in identifying, developing and recommending superior and stable sorghum genotypes for highland environments. To address these challenges, the present study aimed to identify and develop new, high yielding and stable sorghum genotypes across highland environments for yield and key agronomic traits. A total of 131 sorghum genotypes were scrutinized using a randomized complete block design (RCBD) with three replications in a row-column arrangement. Genotypic performance for grain yield, days to flowering and plant height was assessed using linear mixed model of spatial analysis to reduce spatial variation and further enhance selection efficiency. Across the six test environments, the best linear unbiased predictions (BLUPs) for grain yield ranged from 0.42 tha-1 (ETSC13383-2) at Hirna (HN21NVT) location to 8.3 tha-1 (ETSC13108-3) at Haramaya University (HU19PVT), with the overall mean grain yield varying from 2.2 tha-1 (Adelle) to 4.4 tha-1 (ETSC13153-3). The maximum grain yield was recorded from genotype ETSC13153-3 (4.4 tha-1), followed by ETSC300067 (4.1 tha-1), ETSC13367-1 (4.1 tha-1), ETSC300072 (4.1 tha-1), and ETSC13139-2 (4.0 tha-1), underscoring their superior performance across the tested environments. The genotype ETSC13153-3 outperformed the standard checks Dibaba, Jiru, and Adelle in terms of grain yield by 31.8 %, 38.64 %, and 50 %, respectively. Similarly, the genotypes ETSC300067, ETSC13367-1, and ETSC300072 demonstrated a 46.34 % grain yield advantage over the standard check Adelle, while the genotype ETSC13139-2 outperformed Adelle by 45 %. Additionally, the spatial genetic correlation analysis using heat map provided valuable insights into the relationships among trials, revealing strong positive, negative, and weak correlations of trials. Ultimately, the investigation signified that genotypes ETSC13153-3, ETSC300067, ETSC13367-1, ETSC300072, and ETSC13139-2 were among the highest-yielding and most stable performers across the six evaluated environments and demonstrated their potential for broad adaptation and recommendation in highland sorghum-growing regions. Given their outstanding performance, these genotypes are strong candidates for releasing as new commercial sorghum varieties in the near future. These genotypes hold significant potential for future sorghum improvement programs and are well suited for large-scale production in the highland regions of Ethiopia after an in-depth scrutiny of their superiority and yield stability over time across environments.