PT REA KalTim Plantations have been developed starting in 1994 in the province of East Kalimantan (Indonesia). The performance of the palms since the beginning of harvesting in 1998 is relatively modest, in relation with a significant number of supplying palms, and a low bunch weight. Subsequently oil extraction rate has been significantly affected. The methodology for making a diagnostic and proposals for corrective actions have been based on two points: - investigations about the quality of pollination in relation with poor fruit set mentioned by estate management; - Investigations about the mineral nutrition status of the palms, and possible impact on yield levels.