Simultaneous multivariate selection with genotypic stability index of grain sorghum hybrids

This study aimed to evaluate and select grain sorghum hybrids with adaptability, stability, and high grain productivity in diverse environments through multivariate analyses. A total of 51 experimental genotypes and 4 commercial controls were evaluated in 33 environments during the 2021-2024 growing seasons. In each growing season, 25 genotypes were evaluated, distributed across 7, 9, 10, and 7 environments in the 2021, 2022, 2023, and 2024 growing seasons, respectively. Furthermore, three scenarios were considered based on the combination of growing seasons and recurring genotypes: scenario 1 (2021-2022); scenario 2 (2023 and 2024); and scenario 3 (2021-2024), which were evaluated in 15, 17, and 33 environments, respectively. The traits of plant height (m), number of days to flowering, and grain yield (kg/ha) were evaluated in a randomized complete block design (RCBD) with three replications. Stability and adaptability analysis was performed using the AMMI-2, WAASB, and WAASBY methodologies, and the MTSI multivariate selection index was used to select superior genotypes. The WAASB method proved efficient in determining adaptability and stability in grain sorghum, allowing the construction of the additional WAASBY index, which facilitates the identification of more stable and productive genotypes, and the MTSI index, which, due to its multivariate nature, allows the definition of the desired plant ideotype, making the interpretation of results more accessible. Among the genotypes evaluated, CMSXS3019 and CMSXS3017 stood out for their high stability, high productive performance, and desirable agronomic characteristics, such as plant size and cycle, proving promising for the development of future cultivars.