Category Archives: 1993 Vol 5 No 1

The root system (Elaeis guineensis, Jacq.) I. A modified soil core method for root study

Studies were conducted on a simple technique to quantify oil palm roots using the soil core method. The modifications to existing technique involved the use of 5% sodium hexametaphosphate (Calgon), 0.5 mm mesh sieves and a microwave oven.
A 5% solution of Calgon was found to have no significant effect on the length or diameter of oil palm roots. It was effective in dispersing Rengam series soil (Typic Paleudult). After 12 hours of soaking in 5% Calgon solution, only 8% of the soil aggregates remained larger than 0.5 mm in diameter. This reduced the time of elutriation to about 10 minutes. Loss of tertiary root during the washing process was 3%. None of the secondary or primary roots passed through the 0.5 mm sieve owing to their larger diameters.
Drying did not significantly change the length or diameter of the secondary roots or the length of the tertiary roots. However, the diameter of the tertiary roots was significantly reduced. The diameter (Y) of the fresh tertiary root could be estimated from the diameter (X) of the dry root by the linear equation;

Y = – 0.31 + 1.71 X (r2 = 0.94)

The oil palm roots could be dried in 20 minutes instead of 24 hours by using a microwave oven at low to medium power setting. The sizes of roots did not influence the time of drying when a microwave oven was used.

Correlations between vegetative and yield characteristics and photosynthetic rate and stomatal conductance in the oil palm (Elaeis guineensis Jacq.)

Photosynthetic rate per unit leaf area (A) and stomatal conductance (g) were as-sessed during the dry season of 1988 for a mixed population of 6 progenies in a breeding trial in the Republic of Zaire. There were positive correlations between A or g and yield and total biomass production, but there was no significant correlation between A or g and either Bunch Index or Harvest Index.

These results provide encouraging evidence that crossing igh A palms with palms exhibiting superior partitioning characteristics could be a useful way to increase yields.

However, more work is needed to ensure that correlations between g or A and either dry matter production or yield arise because of genotypic effects rather than environmental variation.

Index selection utilizing plot and family information in oil palm

Index selection utilizing plot and family (full-sib and half-sib) information has been demontrated in selecting palms for cloning in a progeny-test trial on hybrids of Deli dura (D) x Dumpy-AVROS pisifera (P).

Inclusion of plot information did not significantly improve the precision or efficiency of the single trait indices for five traits; oil yield (Y), bunch number (BNo), height increment (HINC), kernel to fruit ratio (KF) and mesocarp to fruit ratio (MF); or of the multiple trait indices involving the first three traits. Inclusion of family information greatly improved the precision for the traits Y, KF and MF, which were poorly heritable but improved it to a lesser degree for the more heritable traits, BNo and HINC.

Although the inclusion of information from plot, family and correlated traits in an index would greatly improve the selection efficiency (by as much as 60%) over mass selection for Y, the expected quantum improvement was only about 13% of the trial mean.

The expected selection response from the multiple trait indices involving Y and HINC as objective traits indicated that it was possible to achieve significant reduction in height increment without sacrificing the efficiency of selection for yield in this Deli D x Dumpy-AVROS P population.

Identity characteristics of Malaysian palm oil products:fatty acid and triglyceride composition and solid fat content

An earlier paper dealt with the identity characteristics of iodine value, slip melting point, cloud point, refractive index and apparent density of palm oil products. This paper concludes the work with a description of the fatty acid and triglyceride composition and the solid fat content of these products. The relationships between the contents of palmitic and oleic acids and between C48, C50 and C52 triglycerides were plotted graphically. A plot of palmitic acid versus oleic acid gave a linear relationship. Linearity was also observed in the plot of C52 versus C48. The graphs were useful for evaluation of palm oils contaminated with other oil products. The fatty acid composition of palm oil and palm stearin were generally similar to oils surveyed in 1980. Some differences were noted in the dioleopalmitin or the C52 triglycerides of palm oil which were lower in values in the present work. Similarly, triglycerides of the palm oleins reflected the lower iodine value of the oil. The present survey shows a slight compositional shift towards lower iodine values in palm oil and palm oleins while palm stearins remain widely variable in composition.

Effect of some additives on resistance to crystallization of palm olein

The effect of certain food additives namely sorbitan tristearate (trade names : Famodan TS and Kemest S65K), polyglycerol esters (THL-3 an THL-9) and lecithin on the resistance to crystallization of palm olein (IV 56, IV 60 and IV 65) during storage at 5°C, 10°C, 15°C and 20°C was studied. The levels of additives added were at 0.01% and 0.10%. Although Famodan TS at 0.10% seemed to promote crystal formation at temperatures of 15°C and below, it in fact delayed crystallization of palm olein at 20°C. Among the additives evaluated, THL-9 showed the best results, as crystal formation was delayed at 5°C, 15°C and 20°C. The addition of THL-9 at 0.10% resulted in a very significant improvement in the stability of palm olein stored at 20°C. Palm olein (IV 56) containing 0.10% THL-9 remained clear for 29 days at 20°C, compared with only 24 hr for the control sample. The addition of lecithin improved the stability of palm olein at 20°C but not at lower temperatures. All the additives studied helped delay crystallization of palm olein at 20°C. With Famodan TS, S65K, THL-3 and THL-9 (at 0.10%) palm olein (IV 65) remained clear for more than 180 days.

Inter-firm variance, industry structure and public policy: An approach to improving the cost competitiveness of the palm oil milling sector

This article proposes an industry-level approach towards improving the competitiveness of the palm oil industry with reference to the fresh fruit bunch (FFB) milling sector. The approach can be described as a cross-sectional inter-firm cost variance analysis, which evaluates the cost performance of a firm by comparing its costs with the average or standard in the industry. The approach also analyses the structure and policy environment of the industry, and their effect on costs, as a means of identifying and instituting policies and policy instruments that would improve the structure and competitive base of the industry.