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Abstract |
The
Effects 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-1
yr-1 together with inorganic N and K fertilizers at rate 1 (0.735
kg N and 1.75 kg K palm-1 yr-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.
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| Effects
of physical and Chemical Pre-treatments on Xylose 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 H 2
SO 4 to 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.
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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.
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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.
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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.
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