Elephant grass ecotypes for bioenergy production via direct combustion of biomass

• Cameroon group showed more aptitude for biomass combustion than Napier group.
• In a genetic breeding program should be given priority to Cameroon group.
• There are association between calorific value and morpho-agronomic traits.
• It’s possible to increase calorific value by selection via morpho-agronomic traits.

Several perennial grasses have been studied as energetic feedstock due to high lignocellulosic production, making it an alternative bioenergy source. This is the first study to investigate the aptitude of elephant grass (Pennisetum purpureum Schum.), aiming to breed it for bioenergy production via direct combustion of biomass. The evaluation of the aptitude and the estimates of the genotypic values were carried out using the mixed models methodology. The canonical correlation analyses were carried out among morpho-agronomic and biomass quality traits for the groups Napier and Cameroon. Complementarily, it was used path analysis with calorific value as the principle variable. Elephant grass presented 22.59 Mg ha−1 mean biomass production. Cameroon group presents the greatest aptitude to be used as bioenergetic raw material via direct combustion of biomass, with 24.13 Mg ha−1 total dry biomass, and 18.16 MJ kg−1 calorific value. The ash content has high correlation and high direct effect on the calorific value. Genetic breeding for morpho-agronomic traits within the Cameroon group is recommended. The canonical correlation analyses and path analyses indicate that in the initial stages of elephant grass breeding program, there is a possibility of indirect selection via morpho-agronomic traits to obtain genetic gain in calorific value. In this sense, tandem selection within the Cameroon group could be a good option, in which the genotypes with the tallest and the thickest stalk diameter should be selected among the genotypes with the greatest dry matter content.