Genotype-environment interactions in elephant grass: identifying superior genotypes for energy

Elephant grass (Cenchrus purpureus (Schumach.) Morrone) combines high biomass potential with wide adaptability, making it a strategic crop for both forage and renewable energy production. Its broad genetic base provides opportunities for breeding programs aimed at improving dry matter yield (DMY) and stability across environments. In this study, genotype × environment interactions were investigated using the GGE biplot method. A randomized complete block design with three replications was adopted to evaluate genotypes across four harvests, considered as distinct environments. The first and second harvests accounted for the largest proportion of genotype variation, suggesting that early growth stages are the most informative for selection. Genotype G15 (FIII) produced an average of 18.2 t ha-1 of DMY, surpassing the overall mean by 12%, while G9 (FII) exhibited consistent performance across environments, indicating broad adaptability. Together, these results highlight G15 as a high‑yielding option and G9 as a stable genotype for energy applications. However, the study was limited to favorable conditions, and further trials under water stress and in additional environments are required to validate these recommendations.