Category Archives: 2011 Vol 23 April

Commercial-scale propagation and planting of elite oil palm clones: research and development towards realization

The announcements of breakthroughs in plant regeneration from tissue cultures of oil palm in the 1970s ushered in a new chapter in oil palm genetic improvement with projected yield increase of clones exceeding 30% over hybrid seeds. However, the subsequent ubiquitous appearance of the mantled fruit somaclonal variant in regenerated palms resulted in the early commercial oil palm tissue culture laboratories reverting to further research and development (R&D). Applied Agricultural Resources Sdn Bhd persisted and, through its R&D, circumvented the impeding issues of unacceptably high fruit mantling, and low efficiencies of tissue culture amenability and selection of elite palms. In the process, it has established viable large-scale commercial propagation of oil palm clones by gel and liquid culture methods by the late 1990s. This achievement has since been emulated by more than a dozen commercial laboratories in Malaysia and elsewhere, producing about 3.5 million ramets per year. This apparent success has led industry to believe that oil palm cloning is an established and efficient technology, and that more tissue culture laboratories to produce more high-yielding clones to replace hybrid seeds in planting and replanting will resolve the stagnating national yields.
Much of the increased ramet production comes from more laboratories culturing more palms than in improved cloning efficiencies. Most of the clones currently produced are also derived either from advanced dura (D) x pisifera (P) hybrids or from commercial DxP fields with low heritability for yield. Consequently, the expected yields of the clones would not be much different from those of near true F1 and clonal hybrids which are currently available at a much reduced cost and without the attendant mantling risk. The agro-management needs of clonal plantings to maximize their fruit bunch yield potential have yet to be systematically addressed through scientific experimentation. Cloning ortets from the early or recombinant phases of hybrid breeding programmes would be more efficient with the wider genetic variability and higher heritability for yield and other desirable traits. Perhaps the biggest advantage of cloning would be in the early commercial exploitation of new genetic materials from introgression programmes of wide intra- or inter-specific crosses which would also broaden the genetic base of the commercial plantings to reduce the risk of genetic vulnerability to pests, diseases and environmental stress.
Clones are unlikely to supersede hybrid seeds as the dominant oil palm planting material until the amenability and fidelity deficiencies in tissue culture have been further resolved or circumvented, and their field performance advantage over concurrent improved hybrids clearly demonstrated.

Farmed fish as biological agents for extracting residual palm oil in discarded spent bleaching clays from the palm oil refining industry

Spent bleaching clays (SBC) from palm oil refining contain 20% to 30% adsorbed oil that cannot be recovered economically. This article highlights research conducted to evaluate the potential use of this waste product in the feeds of farmed fish. The impact of graded dietary levels of SBC on growth, feed utilization, body composition, fish health and water quality parameters in feeding trials conducted are discussed. High dietary levels of SBC can be incorporated into catfish and tilapia feeds without any significant negative impact on their growth and health. Nevertheless, total solids and total suspended solids concentration in tank culture water increased significantly concomitant to the increasing dietary levels of SBC fed to the fish. The issue of heavy metal accumulation in fish tissues will also be discussed in the context of current global legislation in regards to feed and food safety. The potential advantages and challenges in using palm oil-based SBC in aquafeeds will be highlighted. It is concluded that farmed fish can be effectively used as low-technology biological agents for the economical extraction of the adsorbed oil in SBC from palm oil refining. Application of this concept will bring benefits to the palm oil, aquaculture and waste disposal sectors.

Formulation of trans-free and low saturated margarine

Palm stearin (POs) is a good choice for trans-free hard stock. POs with various iodine values (IV) have distinct solid fat content (SFC) profiles useful in soft margarine formulation. Palm kernel oil (PKO) maintains the margarine with high consistency at low temperatures, but the margarine is soft at serving temperature. The study revealed that formulation work either using bulk oils and fats (sample 900), interesterified hard stock (sample 905) and simple blend of hydrogenated fat and soft oil (904) can achieve similar fatty acid composition, but not the same SFC profile. Sample 905 contains palm-based hard stock from an interesterified product of a fully hydrogenated POs (IV=0) and PKO blended with sunflower oil (SFO) containing 36.1% total saturated fatty acids. Margarine sample 1089 is trans-free and has a low saturated fat formulation. Despite its low saturated (17.8%) and polyunsaturated fatty acid (9%) content, its high monounsaturated fatty acid (73%) content stabilizes the crystal development during storage at 5°C, 10°C and 15°C for 25 days with no significant post-crystallization. POs is an excellent hard stock for formulating trans-free margarine with low saturated fat content.

Physico-chemical properties of mixed anionic/cationic surfactant solution: mixtures of sodium laurate methyl ester α-sulphonate and tetradecylltrimethlammonium bromide

Interface activity between liquid and air (liquid/air) of palm-based anionic surfactant sodium laurate methyl ester α-sulphonate (C12MES), cationic surfactant tetradecyltrimethylammonium bromide (TTAB) and their mixtures at various mixing ratio was investigated using surface tensiometer. Variation of surface tension with concentration was used to determine the critical micelle concentration (CMC) of the individual surfactants as well as their mixtures at different mixing ratios. It was observed that the CMC for the mixed surfactants were 10 times lower than its individual counterpart. This showed that the surfactant mixtures were more effective and had higher surface activity than their single components. The surface tension at CMC for surfactant mixtures were around 25 mN m-1, where as for single surfactants, the value was above 28 mN m-1. Foaming properties (such as foaming power and foaming stability), wetting and emulsification performance of the mixed surfactant systems was also evaluated at different water hardness in this work. Mixed surfactants especially at equimolar mixing ratio were found to exhibit superior performance as compared to their individual parent surfactants.

Demographic parameters and reproductive performance of the assassin bug Sycanus dichotomus Stal. fed on mealworm Tenebrio molitor L.

The reproductive performance and demographic parameters of Sycanus dichotomus Stal. fed on mealworm Tenebrio molitor L. were studied in the laboratory under the ambient environment of 28 ± 2°C, 70%-90% RH and 12 hr photoperiod. Eggs that were laid in tight clusters of 15-130 eggs per cluster hatched within a mean of 19 days with 6.27% hatchability. The majority of the eggs that were in small clusters were infertile, while larger uniform clusters contained a higher percentage of fertile eggs. There were five nymphal instars. All nymphal stages were reddish in colour. The mean longevity was two to three weeks each for the first to third instars, while at least one week each was needed for the fourth and fifth instars. The total developmental time from egg to adult took 87 days with the females reaching adulthood three days sooner than the male. Adult females survived for an average of 197 days with a median natural mortality (NM50) value of 150 days, while the males endured for an additional 13 days with NM50 value of 165 days. Adults were observed to engage in repeated mating for one week before females proceeded to lay eggs by the third week of post-emergence, with oviposition duration lasting for 186 days. A mean total of 959 eggs were produced during a female’s life-span. The age-specific life table revealed a high rate of combined first and second nymphal mortality, amounting to 63.0%. Pertinent life table parameters, Ro of 137, rm of 0.190 and l of 1.138, were achieved within a generation time of 38.2 weeks, allowing the population to double in 5.4 weeks.

Vermicomposting of different types of oil palm fibre waste using Eudrilus eugeniae: a comparative study

Earthworms (Eudrilus eugeniae, the African Nightcrawler) were tested as inoculants in the vermicomposting process in relation to their capacity to compost the various types of oil palm biomass. The different types of oil palm biomass used were empty fruit bunches (EFB), oil palm fronds (OPF) and oil palm trunks (OPT). The oil palm biomass was composted and vermicomposted for 84 days under controlled conditions. In the study on the effects of earthworm digestibility towards the major lignocellulosic components (cellulose and lignin) of EFB in the vermireactors (EFB WORM), results showed a significant degradation rate of the cellulose. A similar trend was also observed for lignin degradation. Meanwhile, lower rates of the lignocellulosic degradation were observed for EFB, OPF and OPT in the control reactor (without earthworms). Vermicompost obtained showed an increase in heavy metal contents in EFB WORM, OPF WORM and OPT WORM, but the contents were still within the range of limits allowable. A significant decrease in C/N ratio and increases in total Kjeldahl nitrogen, total available phosporous and total potassium were recorded for EFB WORM over the control (EFB, OPF and OPT). EFB fibre was found to be the best oil palm fibre for vermicomposting as compared to OPT and OPF fibre.

Development of a mechanization selection system for oil palm plantations with alternative planting patterns

This article describes a study on the conceptual design and development of the most efficient mechanization selection system for oil palm plantations with alternative planting patterns. The study was conducted by extrapolating various planting patterns based on the existing triangular pattern and comparing these with machine information based on a constant mechanization package made for a large and rather flat area. The comparison of machines was conducted in earlier studies based on a combination of various plantation operations like fertilizer application, weeding, harvesting, in-field collection and loose fruit collection. The results obtained suggest that the most efficient planting pattern is the triangular planting pattern. The findings from this study will help to determine the efficiency of each machine besides optimizing the cost of implementing the package .

Regeneration and characterization of spent bleaching clay

Spent bleaching clay (SBC), a solid waste generated from the palm oil refinery, may be recycled rather than being simply disposed off in landfills. The aim of this research was to investigate the heat regeneration of SBC and to evaluate the performance of the heat-treated SBC in bleaching crude oil. Two types of SBC were used, i.e. (a) acid-activated clay, and (b) natural clay. Two types of regeneration processes were performed, i.e. (a) solvent extraction followed by heat treatment, and (b) direct heat treatment. Heat treatment was conducted in a box furnace at temperatures ranging from 400°C to 800°C. Red colour indices of oils were used to determine the regeneration efficiency. Spent bleaching clay produced by the direct heated-regenerated spent bleaching clay (HRSBC) yielded a higher regeneration efficiency than the deoiled-heated-regenerated spent bleaching clay (DHRSBC) produced by solvent extraction and heat treatment. This is because moisture, impurities and dirt were more completely removed by direct heating than by solvent extraction. Specific surface area, total pore volume and average pore size of SBC were measured using the nitrogen adsorption-desorption method. The results show that the HRSBC at 500°C possessed a higher specific surface area and total pore volume and gave a better bleaching efficiency than HRSBC at 400°C and 800°C. All the regenerated SBC samples were mesoporous material.

Deoiling efficiency for oil extraction from spent bleaching clay and the quality of recovered oil

The disposal and reuse of spent bleaching clay (SBC) from the palm oil processing industry is a problem of growing importance. Although today the only practical way of removing SBC is by disposal, extraction with organic solvents is a well-known method of deoiling contaminated SBC. Various hydrocarbon solvents are used as solvents to extract the residual oil in SBC. In this study, SBC was deoiled by hexane extraction. The content of oil and minor components in SBC was more than 40% by weight. All the extracted oils, irrespective of the solvent used, had poorer quality than crude palm oil (CPO). The outcome of the study showed that the amount of extracted oil using the conventional Soxhlet extraction method was higher than by batch extraction. However, for extraction of the residual SBC using the batch method, a SBC to solvent ratio of 1:7 should be more suitable as more of the impurities are removed. The aim of this study was for a complete separation of the residual oil from SBC. The oil and SBC were analyzed and tested. The results show that SBC still had an activity approximately 80% that of fresh bleaching clay .

Trap for the auto dissemination of Metarhizium anisopliae in the management of rhinoceros beetle, Oryctes rhinoceros

An inoculation trap for the auto dissemination of spores of Metarhizium anisopliae for the management of Oryctes rhinoceros in the field was designed and tested. The efficiency of the inoculation trap in capturing the adult rhinoceros beetles was found to be as good as the commercial pail type trap. The trap capture rate was 2.5 adults per trap per night (a/t/n), no different (at P>0.05) from the capture rate by the pail type trap (2.4 a/t/n). A performance test showed that 66.7% of the trapped adults that escaped from the inoculation trap were subsequently confirmed dead due to infection by the fungus. Laboratory tests also found that the infected adults had disseminated the spores to the breeding site, killing 91.7% of the larvae by fungal infection. The mortalities of the released inoculated adults were between 63% and 69%, due to infection by M. anisopliae. A field test showed that the percentage of trapped adults leaving the trap was between 85% and 95%. Both rates of spore solution (at 2 and 4 g litre-1) caused high mortality to adults within the period of 15-30 days after trapping (DAT), and complete mortality was recorded at 45 DAT. Some 75% to 90% of the dead adults were confirmed to be infected by M. anisopliae. The density of viable spores collected from the soil in the trapping region showed an increase, suggesting that the M. anisopliae had been established in the breeding sites of the beetle.