Estimation of variance components and heritability of bunch yield and yield components in the oil palm (Elaeis guineensis Jacq.)

Abstract In an experiment involving 24 single‐cross progenies of oil palm conducted at the Nigerian Institute for Oil Palm Research, 9‐year data of fresh‐fruit yield and its two components, annual bunch number and single‐bunch weight, were recorded. Means of progenies of each of the three traits obtained from 1–9‐year records were used in analyses of variance according to a repeated‐measures design. The results were then used to estimate variance components due to progenies and progeny × year interactions. These estimates were then used to estimate heritability for yield and yield components based on progeny means, which were assumed to be calculated from 1–9 years of harvests. The results revealed that heritability estimates of fresh‐fruit yield and its two yield components were not reliable based on the first‐year harvest data. The single‐bunch weight had a slower rate of improvement than the other two traits when more years were used for the estimation. Heritability can be expected to be over 80% for fresh‐fruit yield and bunch number based on 1‐, 3‐, and 4‐year means, respectively. Six‐year data are required for single‐bunch weight to reach the same heritability measure.