Correlations and path coefficient analysis for energy biomass production components in elephant grass (Pennisetum purpureum Schum)

摘要

Elephant-grass (Pennisetum purpureum Schum) is known to have a great potential for biomass production, but studies on genotyperesponses to different sites and growing seasons are still scarce and necessary. This study aimed to estimate correlation and pathcoefficient analysis for biomass production trait in elephant grass under semi-annual cutting cycles. The experiment was conductedfrom 2012 to 2015 in a randomized block design with two replications. Seventy-three elephant grass cultivars (genotypes) wereassessed during six cutting cycles. Cuts were manually performed when grasses reached a height of 1.5 m (semi-annually). Thefollowing variables were analyzed HGT, SD, NT, LW, %DM and DMP. Data were subjected to individual and joint variance analysis, inaddition to analysis of genotypic, environmental, and phenotypic correlation and path analysis decomposition. Both genotypes andcuts had significant effects on all the variables. HGT, SD, and LW were significant, positive, and genotypically correlated with DMP.In terms of direct effects on DMP, NT (1.44) stood out with the highest effect and total correlation, thus showing a majorcontribution to DMP increases. Regarding indirect effects, %DM had a positive influence on DMP via NT and LW. The selection ofplants with a high %DM included genotypes with lower SD, HGT, and LW and higher NT. The environmental component had agreater influence on the relationships involving both NT and SD.