Category Archives: 2002 Vol 14 No 2

The effects of oil palm empty fruit bunches on oil palm nutrition and yield, and soil chemical properties

Mulching with oil palm empty fruit bunches (EFB) supplemented with inorganic fertilizer is widely practiced in oil palm plantations but with little evidence in support. In the absence of technical information, estates are applying large amounts of N and K fertilizers with the EFB due to the need to maintain high yield. This study was initiated to study the effects of applying N and K fertilizers together with mulching on oil palm nutrition and yield and the soil chemical properties. Three fertilizer rates were applied at two frequencies together with three rates of EFB in a 2 m band in the inter-rows. The experiment was conducted on 17-year-old palm planted on Durian series soil. Application of EFB at 37.5 t ha-1yr-1together with inorganic N and K fertilizers at rate 1 (0.735 kg N and 1.75 kg K palm-1yr-1) improved the leaf N and K levels, bunch number, bunch weight and fresh fruit bunch yield, while leaf Mg was depressed. EFB mulching also improved the soil exchangeable K, Ca and Mg and pH. The frequency of fertilizer application did have any effect on the leaf nutrient levels and yield. Thus, EFB mulching supplemented with N and K fertilizers should always be advocated for improving oil palm nutrition and yield

Effects of physical and chemical pre-treatments on xyclose and glucose production from oil palm press fibre

Several physical and chemical pre-treatments were attempted to maximize the production of xylose and glucose from the hydrolysis and saccharification of hemicellulose and cellulose from oil palm press fibre. Bleached (holocellulose, PI), alkaline treated (PII) and untreated oil palm press fibre (PIII) of different sizes (<0.3 mm, 0.3 – 0.4 mm and >0.4 mm) were first pre-hydrolysed with H2SO4to produce xylose. All the treatments showed that the maximum yield of xylose was obtained from fibre of >0.4 mm, and the lowest from fibre of <0.3 mm. The latter result is believed to be due to residual kernel, shell and other impurities present from the grinding. At the optimum size of >0.4 mm, sample PII gave the highest yield of xylose (67.8 g litre-1) and the lowest yield was from PIII (29.2 g litre-1) while PI gave 44.5 g litre-1. The percentages of conversion of dry weight of oil palm press fibre were 23.9%, 9.3% and 22.3%, respectively. Saccharification of the residues from pre-hydrolysis of PI, PII and PIII (celluclast 1.5 L; 1500 IU g-1, novozyme 188; 250 IU g-1, pH 4.8, temperature 48ºC, agitation at 150 rpm for 48 hr) gave yields of glucose of 9.8, 35.8 and 18.8 g litre-1, respectively. The percentages of conversion of dry weight of oil palm press fibre were 18.0%, 45.2% and 27.8%, respectively. The acid hydrolysed residue of PI treated with 2% (w/v) NaOH at 121ºC for 120 min (after soaking overnight at ambient temperature) gave the highest yield of glucose from saccharification (73.2 g litre-1) (51.3% conversion of the dry weight of oil palm press fibre). The studies indicated that chemical pre-treatments of the fibre with mild acid followed by alkaline delignification before saccharification with enzyme, gave the maximum yields of xylose and glucose

Variability in fatty acid composition iodine value and carotene content in the MPOB oil palm germplasm collection from Angola

Forty-two progenies of oil palm (Elaeis guineensis Jacq.) from the Malaysian Palm Oil Board (MPOB) germplasm collection from Angola were analysed for their fatty acid composition and carotene content using gas chromatography and UV spectrophotometry, respectively. Their variations in the fatty acid traits and carotene content were considerably larger than in the current breeding materials in Malaysia. Their means for all the traits, except palmitic acid, were also higher. The phenotypic correlations were negative between palmitic/stearic acids and palmitic/oleic acids, so increasing palmitic acid is likely to decrease stearic and oleic acids, and vice versa. A negative relationship was also found between oleic/linoleic acids. A number of progenies had carotene contents >1000 ppm and one progeny had iodine value >60. The heritability estimates for the individual fatty acids and carotene content were moderate to high, indicating good genetic control over the traits. The Angolan germplasm is therefore potentially useful breeding materials for improving Malaysian oil palm for commercial planting. However, further studies are needed before the breeding materials proper can be selected and used in actual breeding

Fruit set and oil palm bunch components

Hand pollination was carried out using different amounts of pollen to produce different levels of fruit set in fruit bunches of 12-year-old DxP oil palms planted at Bangi, Selangor. Seventy ripe bunches were sampled and their fruit set ascertained. The fruit set ranged from 2% to 96%. Open pollinated bunches had a mean fruit set of about 80%. This indicates that the weevils were more efficient pollinators than hand pollination. There was an expected increase in fruit set with increasing amount of pollen from 0.0001 g to 0.01 g used in the hand pollination. The bunch weight increased with fruit set to a maximum of about 24 kg at 90% fruit set. Bunch development was affected by the increasing number of fertilized flowers, which increased the sink for carbohydrates. The increased sink under a limited carbohydrate supply led to a reduction in the mean fruit weight and an increase in parthenocarpic fruits in the inner bunch. The kernels had a higher priority for carbohydrate supply for their development than the mesocarp or shell

Properties of medium density fibreboard from oil palm empty fruit bunch fibre

Medium density fibreboard (MDF) is increasingly popular in the world today. In Malaysia, MDF is made using rubberwood. However, with the diminishing supply of the wood, an alternative raw material is needed. Empty fruit bunches (EFB) is a readily available waste from the oil palm industry, possibly suitable for MDF. It, however, contains residual oil which had to be removed by two pre-treatments – boiling in water and 2% sodium hydroxide (NaOH). In addition, two resin contents (4% and 6%) were used in a factorial 2 x 2 experiment. Removing the oil improved the MDF properties. Although NaOH removed more oil, its fibre was coarser with a higher bulk density (57 vs. 42 kg m-3 ). The panels produced with the water pre-treated fibre therefore had better mechanical [modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding strength (IB)] and physical [water absorption (WA), thickness swelling (TS) and linear expansion (LE)] properties than the NaOH pre-treated fibre. The higher resin content (6%) also conferred better mechanical and physical properties. All the panels, except those produced with 4% resin and NaOH, easily met the minimum strength requirements by the National Particleboard Association (NPA) for MOR, MOE and IB. In contrast, all the panels were below the standards for WA and TS. The LE was also substandard with the exception of the water panels with 6% resin. Although much work remains to be done, EFB seems an eminently suitable raw material for MDF.