Correlation and Path Analysis of Palm Oil Yield Components in Oil Palm (Elaeis guineensis Jacq.)

Abstract

This research aimed to evaluate the correlation coefficients, direct effects and indirect effects of agronomic characters on palm oil yield components for selection and improvement of next-generation oil palm populations. The seven crosses of oil palms aged 4 yr were investigated at three locations in southern Thailand. The experiment at each location was designed as a completely randomized design with five replications. Data on bunch yield, yield components and bunch components were collected from July 2009 to June 2010. Combined analysis was used to estimate the variance and covariance for the calculation of correlation coefficient and path coefficient values. The results showed that the bunch yield, single weight, fresh mesocarp per fruit and fruit per bunch had positive genotypic and phenotypic correlation coefficient values with regard to palm oil yield (1.03, 0.93, 1.70, 0.13 and 0.85, 0.56, 0.32, 0.34, respectively). The path analysis indicated that the bunch yield, fresh mesocarp per fruit and fruit per bunch had a positive direct effect on both the genotype and phenotype of palm oil yield (1.32, 0.68, 0.27 and 0.94, 0.20, 0.31, respectively). Although, the single weight had a positive correlation coefficient value for both genotype and phenotype, it had a negative direct genotypic and phenotypic effect on palm oil yield. Therefore, palm oil yield improvement should be considered especially in terms of the bunch yield, fresh mesocarp per fruit and fruit per bunch, because these characters had high, positive direct genotypic and phenotypic effects on palm oil yield.