Judul: Optimizing of fertilizer nitrogen and phosphorus doses for oil palm seedling (Elaeis guineensis Jacq.) in Main Nursery
Abstrak: The objective of this experiment was to study the optimum doses fertilizer of Nitrogen and Phosphorus for oil palm seedling (Elaeis guineensis Jacq.) in main nursery. This experiment was carried out at IPB Experimental Station (Plantation Teaching Farm),Cikabayan Dramaga, Bogor, from November 2011 to May 2012. The treatment was laid-out in a factorial randomized block design with three replications. The first factor was N i.e. 0, 8.51, 17.02, and 34.04 g N.plant-1 and the second was P i.e. 0, 2.28, 4.56 and 9.12 g P.plant-1. The result of the experiment showed that vegetative growth increased with fertilizer application. The height and leaf area of plant are affected by interaction between N and P significantly. The total leaf number and steam diameter increased quadratically with fertilizer rate of N and application of P increased linearly. Base on the height of plant and leaf number, optimum recommendation rate of N for oil palm seedling during six months in main nursery is 21.99 g N plant-1, by aplication every month i.e. 1.60, 1.14, 2.80, 4.01, 5.73 and 5.74 g N plant-1.month-1. Optimum recommendation rate of P is 4.24 g P plant-1 by aplication every month i.e. 0.22, 0.44, 0.76, 0.18, 0.94, and 1.70 g P.plant-1.month-1. The seedlings that resulted from experiment could be requisite accomplished to used on commercial planting.
Keyword: 

Judul: Optimasi Dosis Pupuk Majemuk NPK dan Kalsium pada Bibit Kelapa Sawit (Elaeis guineensis Jacq.) di Pembibitan Utama
Abstrak: 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.
Keyword: 

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
Keyword: