Category Archives: 1998 Vol 10 No 2

Stages in the vegetative propagation of oil palm, Elaeis guineensis Jacq. through tissue culture

Oil palm (Elaeis guineensis Jacq.) was vegetatively propagated by tissue culture in NIFOR on a NAA medium which provided a very short callus stage. The following stages were identified; callus (initiation and maintenance), embryoid, plantlet (ramet), prenursery (sand culture), nursery, and field planting. Normal male and female inflorescences which led to normal fresh fruit bunches (FFB), were produced by the tissue culture palms two and a half years after planting the plantlets in the field.

Force and energy requirements for cutting oil palm frond

A study was conducted to investigate the effect of cutter design, cutting angle and frond maturity on the specific cutting force (FOCSA) and energy (ENCSA) requirement per unit cut area for cutting oil paim fronds. Two designs were tested, (i) sickle cutter and (ii) claw cutter. Cutting angles of 90°, 60° and 45° were tested on the three levels of frond maturity.

The results showed significant effects of cutter design, cutting angle, frond maturity and interaction of cutter design and cutting angle on FOCSA and ENCSA requirement for cutting oil palm fronds. The maximum FOCSA for the sickle and claw cutters were 12.2kg/cm2 and 22.9kg/cm2 respectively, while the maximum ENCSA for the sickle cutter and claw cutters were 65.4kg-cm/cm2 and 115.5kg-cm/cm2 respectively. This indicated that the sickle cutter required 47% less FOCSA and 76.5% less ENCSA than the claw cutter. Increasing the cutting angle resulted in higher FOCSA and ENCSA requirements. Also, the more mature the frond, the higher the FOCSA and ENCSA required to accomplish the cutting.

Notes on oil palm productivity. II. An empirical model of canopy photosynthesis based on radiation and atmospheric vapour pressure deficit

Using data on daytime CO flux above the canopy determined by eddy correlation, a simple empirical model was devised based on relationships between CO flux and radiation, and CO flux and atmospheric vapour pressure deficit. The model satisfactorily predicted above-canopy flux from measurements of these variables using site-specific regression constants. The limitations and practical implications of the model are discussed.

Biolistic-mediated DNA delivery and isolation of transgenic oil palm (Elaeis guineensis Jacq.) embryogenic callus cultures

Oil palm (Elaeis guineensis Jacq.) embryogenic calli were transformed with plasmids containing various com- binations of genes encoding β-glucuronidase, phosphinotricin acetyltransferase and hygromycin phosphotransferase, using an electric discharge particle bombardment device. Experiments to optimize the accelerating force for DNA delivery into embryogenic tissue of oil palm were carried out. Selection and culture conditions to allow recovery of transgenic tissue are reported. Stable integration of transgenes was confirmed by molecular analysis. Due to the long time required for regeneration of transgenic plants from oil palm embryogenic callus, this report is significant as it describes, for the first time, conditions leading to the recovery of transgenic embryogenic callus cultures carrying and expressing transformed marker genes.

Notes on oil palm productivity. III. The use of sap flux probes to monitor palm responses to environmental conditions

Using a system developed in France, relative sap flux was measured in trunks and frinds of palms in relation to the potential evapotranspiration (PET) and evapotranspiration (ET) rates deduced from micrometeorological measurements. The method provided a sensitive means of detecting changes in transpirational activity related to radiation, PET, soil water supply and frond aging. Its further use and development are discussed.

The effect of palm-based surfactants as spray adjuvants in glyphosate isopropylamine (IPA)

The utilization of some palm-based surfactants in glyphosate in isopropylammonium (IPA) formulations were tested. Three groups of nonionic surfactants were used, i.e, fatty alcohol ethoxylate CFAE) with five moles of ethylene oxide (EO), 7 EO, 9 EO and 20 EO, fatty amine ethoxylate (FAmE) and alkylpolyglycosides (APG). Cyperus rotundus, a thin-leaf and tuber-producing weed was used to test the efficacy of glyphosate IPA formulations. Twelve glyphosate IPA formulations were prepared and their stabilities tested at room temperature (RT) and 45°C. All the formulations were stable at RT, and nine appeared as one layer after keeping at 45°C for seven days. Efficacy tests were carried out under full sunlight. The application rates were 2.0kg/ha. 1.5kg/ha and 1.0kg/ha of glyphosate IPA, the active ingredient (a.i) per hectare (ha), and the spraying volumes used were 200 litres (l)/ha and 400 1/ha. The surfactant concentrations in the spraying solutions varied from 0,1% to 0.35% (w/w). Visual observation and analysis of variance showed that six formulations gave very promising results for controlling Cyperus rotundus. The formulations were FAmE, FAE (20EO), FAmE/APG (C8-C10), FAmE/APG (C8- C16), APG (C8-CIO), and APG (C8-C16).

Techniques for sampling oil palm roots : II. Root auger for peat soils

Root study in peat is important for understanding the oil palm performance under this limiting soil condition Difficulties arise when studying roots in peat due to its structureless properties. A suitable auger was designed to ease root sampling in peat. The auger enables the extraction of a peat core sample of 10cm diameter by one metre length. Compression of the peat core sample was reduced and root excisions were satisfactory.