Correlation and Path analysis for yield components in Dura oil palm germplasm

Abstract

The purpose of this study was to evaluate linear correlations and their direct and indirect effects on the characters of production for oil palm germplasm. It were evaluated 34 accessions of the Germplasm of Oil Palm from Embrapa considering 37 variables among vegetative characters, bunch yield and bunch components. Data were collected, fortnightly, during consecutive eight years, from fourth to tenth year after planting. It was estimated the matrix of phenotypic and genotypic correlations, and its decomposition into direct and indirect effects through path coefficient analysis. Results showed that Total Bunch Weight at young (PTCFJ) and adult (PTCFA) phase, even as number of bunches at adult phase (NCFA), total bunch weight (PTC), bunch weight (Pcacho), bunch peduncle (PPED), fruit to bunch ratio (RFC), pulp to fruit ratio (RPF), oil percentage in wet pulp (POP), and laboratory oil extraction rate (TEL) had positive and significant correlation (p ≤ 0,05) with oil production per plant at adult phase (POFA): 0.55, 0.72, 0.35, 0,72, 0.49, 0.49, 0.37, 0.53, 0.34 and 0.69, respectively. As expected, there was a negative correlation (p ≤ 0.05) between POFA and the variables almond to fruit ratio (PerAM) (-0.47) and endocarp to fruit ratio (PEF) (-0.45). The path coefficient analysis showed that despite high positive and significant correlations between POFA and many variables evaluated, for few of these correlations was verified a relationship of cause and effect. Variables with significant correlations, and with high direct effect on POFA were NCFA (0,13 direct effect), PTCFA (0,53 direct effect), RFC (0,11 direct effect), RPF (0,10 direct effect), PEF (-011), POP (0,13 direct effect) and TEL (0,35). The variables with higher direct and/or indirect effect to increase the fresh fruit bunch production were PTCFJ and PTCFA. The latter is the most important variable for use in breeding programs and evaluation of the oil palm as it has positive and significant correlations and direct and/or indirect effect in the correlation value for the increase for both bunches production as well as oil palm production.