Importance of palm growth during immaturity and impact on yield at an early stage

The period following oil palm planting is a difficult phase for plantation companies, as no income is obtained while expenses are still relatively high (fertilization and upkeep) and additional to the initial planting investment, i.e. land clearing, field preparation and planting itself. For maximum profitability of this commodity, agricultural practices have to reach a high standard, in order to reduce the length of the immature period and increase the level of the first yields in line with the genetic potential of the palms. An analysis of several field experiments in both Indonesia and the Ivory Coast (West Africa), has revealed the importance of young palm growth and development during the immature period as a key factor for improving precocity and yield levels during the first harvests. In Indonesia, a trial shows that optimum palm growth can improve the precocity of the palms by 2.5 months. Subsequently, yield levels are also significantly improved during the first two years of harvesting. A second trial also proves the importance of growth during the immature period for obtaining maximum yields at an early stage. In both experiments, the key factor appears to be nutritional. In these ecological situations, nitrogen and phosphorus are nutrients with a major impact. In West Africa (Ivory Coast), the importance of growth during the immature period and its relationship with future yields has also been proven in a trial studying specific agricultural practices. In this ecological situation, mineral nutrition aspects do not appear to be a main factor. The analysis shows that better yields are obtained when growth is optimum throughout the immature period, and not only at the end of immaturity. A specific statistical analysis on an estate scale in Indonesia backs these results. A Principal Components Analysis helped to identify the main factors related to yield performance: the nutritional level and subsequent vegetative growth. Based on these observations, recommendations are made for monitoring vegetative development in immature palms as a decision support system for plantation management. For that purpose, growth potential curves have to be drawn up for each planting material and ecological situation. (Resume d'auteur)