AbstractThe diversity and use of forages and grasslands for animal feeding are essential in tropical livestock systems. Seasonal changes are mainly marked by variations in precipitation patterns. Grasslands are managed as perennial crops and therefore must be resilient to tolerate both dry and rainy seasons. The integration of animal production with the genetic aspects of forages is important for helping to identify resilient alternatives for sustainability in livestock systems. This study developed a multivariate and multiharvesting trial (MHT) for plant height, green forage weight (GFW), and dry matter yield (DMY) in a diversity panel of 130 accessions of guineagrass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs] established in the Patía Valley of Colombia. Our study aims to identify interactions among weather conditions and different genotypes for agronomic variables as well as identify outstanding accessions for their productivity and adaptability. The entry mean heritability values were .88, .47, and .39 for the traits plant height, GFW, and DMY, respectively. The genetic correlations among different harvests ranged .5–.9 for plant height and .2–.9 for GFW. Heritability and genetic correlations suggest that plant height and yield are largely influenced by plant genetic effects. The correlation among plant height and yield was .42 for GFW and .33 for DMY. Negative correlations were not found in the agronomic behavior of the materials among the harvests under rainy and dry conditions. The MHT analyzed under the methodology of factor analysis revealed that accessions 16062 and 6982 stood out consistently for plant height, GFW, and DMY across different harvests. These findings strengthen processes in the search for resilient forages in the transition toward eco‐efficient livestock production and provide knowledge on which agronomic variables and forage materials to select, according to criteria of interest to both producers and plant breeders.