Correlation analysis between yield and morphological traits ofhybrid giant napier of different growth years

Abstract： In order to study the relationship between grass yield and morphological traits of hybrid giant napier (Pennisetum hydridum), some important morphological traits including fresh yield, plant height, tiller numbers, etc. were investigated in 2009. Relativity and multiple linear regressions of confirming the dominant morphological traits on impacting yield were also analyzed. The results showed that there were significantly positive correlations among yield and plant height, tillers, numbers of effectual stems；enhanced with the increase of growth years of the hybrid giant napier after planted. The correlation analysis and path analysis found that the greatest direct and indirect effects on fresh yield of hybrid giant napier were its effectual stem numbers, node and tiller numbers. A simple regression analysis showed that the fitting degree of numbers of nodes and fresh yield was the best among the single variables. Moreover, the five linear regression model, Y=-23.742+0.031X1+0.261X2+0.187X3+0.025X4+0.825X5, R2=0.822（P0.01）, was the optimal model for the fresh yield of hybrid giant napier with different growth years. The fresh yield of hybrid giant napier can be predicted by the regression equation. The numbers of tillers, effectual stems and nodes of hybrid giant napier have the most important contribution to its fresh yield.