Agronomic performance and dry matter yield stability of Napier grass (Pennisetum purpureum) genotypes in Southwestern Ethiopia

The study aimed to evaluate the yield performance and stability of 10 Napier grass (Pennisetum purpureum) genotypes. A completely randomized design with three replications was used to assess these genotypes. Genotype and genotype × environment (GGE) interaction and additive main effects and multiplicative interactions (AMMI) biplot models were utilized for analysis. The combined results indicated a significant (p ≤ 0.05) impact on dry matter yield and other agronomic traits. Genotypes and environments contributed to 26.93% and 52.17% of the observed variation in dry matter yield, respectively. The GGE and AMMI biplot models identified promising genotypes based on mean dry matter yield and stability. G3, G1, and G10 genotypes were highlighted as stable with high dry matter yield across different environments compared to others, AMMI analysis also revealed that they had above-average dry matter yield, minimal deviation from the regression line (S2di), and a regression coefficient close to one, which indicated their desirability and stability. Among the 10 genotypes, these Napier grass genotypes were considered the most desirable and stable due to their characteristics. H18 had a longer vector and a small angle with average environmental axis (AEA), making it an ideal environment for selecting superior genotypes accurately. In conclusion, G3 and G1 were identified as ideal genotype candidates for broader utilization under similar environmental conditions.