Oil palm (Elaeis guineensis Jacq.) genetic differences in mineral nutrition: environmental effects on leaflet mineral concentrations of four oil palm progenies

Oil palm fertilizer requirements are based on leaflet mineral concentrations. Four oil palm progenies representing a wide genetic diversity of Elaeis guineensis species and with contrasting K and Mg leaflet concentrations were tested in Indonesia and Nigeria, environments which differ predominantly in climate. During 5 years, we compared oil palm progenies' leaflet mineral concentrations between both countries under abundant fertilizer applications to investigate the extent to which they depend on the environment. In the two studied environments, leaflet concentrations significantly differed between progenies for K, Mg and Ca, but the country effect was not found significant (p = 0.352) for any leaflet mineral's concentration. In both countries, progenies ranked similarly in their mineral categories (lowest and highest cation concentrations within the 4 progenies population), indicating that leaflet mineral concentrations in the tested oil palm progenies are mainly determined by their genetic background. For each progeny, with abundant fertilization, K, Mg and Ca proportions to total leaf cation charge (TLCC) were similar, irrespective of the environments in which the palms were cultivated. We have strong indications that foliar concentrations of K, Mg and Ca are determined by genetic factors which dominate the environmental effect. However, it remains uncertain whether differences in oil palm foliar concentrations between different oil palm progenies imply that they require specific fertilizer amounts to attain an optimal production.