Optimizing Rates of NPK Compound and Calcium Fertilizer for the Growth of Oil Palm (Elaeis guineensis Jacq.) Seedling in Main Nursery.

Abstract

Oil palm is the main estate crop that brought Indonesia as the main producer for palm oil in the world. Palm oil both crude palm oil (CPO) and kernel palm oil (KPO) have been broadening utilized by fractionation (edible oil), margarine, cosmetics, oleo-chemical and bio-diesel industries. The productivity of oil palm could be determined by the quality of seedling both genetically and physically. The production of oil palm seedling takes about 12-14 months through pre nursery (3-4 months) and main nursery (9-11 months). Fertilizer management had been necessary for oil palm seedling growth. Therefore, the accuracy fertilizer rate would be the main key to maintain the oil palm seedling growth physically as it would have produced the maximum growth of oil palm seedling. This research was aimed to evaluate rates of NPK compound and calcium fertilizer for the growth of oil palm seedling in main nursery. Other objectives were to know the interaction effect between NPK compound and calcium fertilizer and to produce the high qualified oil palm seedling. The experiment was conducted in IPB Experimental Station, Cikabayan, Darmaga, Bogor from December 2011 to November 2012. The two factor experiment was designed in a randomized block design with three replications. The rates of NPK compound fertilizer (15-15-15) were 0, 115, 230 and 460 g seedling-1. The rates of calcium fertilizer were 0, 5, 10 and 20 g seedling-1. In general, there was no interaction effect between NPK compound and calcium fertilizer on variables observed, except on plant height 3 Months after Application (MAA). NPK compound fertilizer had the significant quadratic effect on plant height, leaf number, stem diameter and chlorophyll content. But, it had the significant linear effect on plant height 5 MAA and stem diameter 3 MAA. The calcium fertilizer had the significant linear effect only on plant height 1 MAA and other variables were not affected by calcium fertilizer. The linear effect showed that the highest rate would still increase the seedling growth. The quadratic effect showed that the seedling growth would decrease by rate higher than the optimum rate. The oil palm seedling height of NPK compound rate 230 g seedling-1 on 8 MAA attained 85.48 % up to oil palm seedling standard for 12 months since pre nursery. Stem diameter and leaf number attained 106.92% and 65.56% respectively. Based on plant height and stem diameter, recommended rate of NPK compound fertilizer 15-15-15 was in the range of 333.00 g seedling-1 for eight months. Recommended rates for each month were 7.00, 7.00, 19.45, 59.25, 66.3, 61.55, 58.97 and 54.16 g NPK seedling-1. The optimum rate of calcium was not obtained from this experiment.