Palm wine and fruit yield responses of oil palm (Elaeis guinensis) trees to pruning frequency and season in the rain forest ecology of southern Nigeria

During the early days of commercial oil palm cultivation in Southern Nigeria, it was thought desirable to prune the leaves subtending female inflorescences to allow the bunches room to develop.1,2 This practice often led to as many as 15% of the green leaves being pruned. Doubts about the wisdom of this standard of pruning led to two experiments being laid out for this study. The results of these experiments Rutger3 showed that any pruning in excess of cutting the leaf subtending a ripe bunch led to a reduction in yield. The experiments did not have any treatment with less severe pruning. Bunting et al.,4 stated that the principle that pruning showed never removed more leaves in a year than are produced by the palm in a year. In another experiment, Ubi et al.,5 favored considerably less pruning and mentioned that although only dead and withered leaves should be pruned, harvesting made it necessary that the leaf subtending a bunch should be cut at the same time as the bunch.6,7 The authors also quoted Rutgers1 as stating that severe pruning led to an immediate increase in yield which was then followed by a serious decline from which the palms eventually recovered. In West Africa, pruning practices have been based on regular cleaning rounds aimed at removing only the dead and dying leaves8,9 Bunting et al.,4 presented the chemical analyses of 20 leaves (one year’s production). N – 38%; P – 6%; K – 8%. It can clearly be seen that the removal of large number of leaves from the field will bring a rapid drop in fertility of the soil. It was in consideration of these facts and the need to take a close study of pruning effect on palms of Southern Nigeria that this study was undertaken to examine the effect of some pruning experiments of oil palm in Southern Nigeria. Materials and methods