Pertanika Vol. 9 No. 2 December 1986
PERT-0369-1986
Fruit Rot of Durian Caused by Phytophthora palmivora
T. K. Lim and L. G. Chan
Keywords
Durian ; fruit rot; Phytophthora palmivora
Abstract
A severe fruit rot of durian fruits in Bentong and Raub in Pahang; Dengkil in Selangor; Muar and Kluang
in Johore was found to be caused by a Phytophthora sp. Besides fruits, isolates of the pathogen were also
capable of infecting roots, stem and leaves of durian. The isolates were identified as Phytophthora
palmivora, cross-inducing (heterothallic) and of the Al mating type, producing oospores when paired with a
standard A2 mating type of P. palmivora and another A2 isolate from cocoa but not with an Al mating type
of P. parasitica.
PERT-0371-1986
Soil Temperature Regimes under Mixed Dipterocarp Forests of Peninsular Malaysia
Abdul Rahim Nik , Baharuddin Kasran and Azman Hassan
Keywords
Soil temperature regimes; mixed dipterocarp; forested; open; various depth; Peninsular Malaysia.
Abstract
Soil temperature regimes of forested and open conditions at selected depths of 5, 10, 20 and 30 cm, were
reported based on data collected over a two-year period. Results showed that temperature of soil under
forest cover was consistently lower than of the open by 4 to 6°C due to shading effect' of forest cover. The
top 5 cm layer in the open showed the greatest variation whilst insignificant differences were observed
among layers under forest. Weighted average soil profile temperature for both conditions seemed to follow
closely the mean air temperature. However, open air temperatures consistently recorded lower values.
PERT-0372-1986
Light Requirements of Shorea Materialis Seedlings
Aminuddin Bin Mohamad
Keywords
Light* requirements; Relative Light Intensities; shoot root ratio; dry matter production.
Abstract
This paper deals with the growth responses of Shorea materialis seedlings to various light conditions under
shade chambers of 21%), 33%0 and 55%0 Relative Light Intensities (RLI), compared to open conditions
100%0 RLI). The best growth was observed between 30-55%) RLI i>n terms of optimum increases in
height, stem diameter, leaf area and overall dry matter. The weight ratio of shoot to root in the open is
lower than that in the shade conditions.
PERT-0373-1986
Water Use of Young Citrus as a Function of Irrigation Management and Ground Cover Condition
Kamarudzaman Aribi
Keywords
Trickleirrigation; lysimeter; potential evapotranspiration; crop evapotranspiration; crop water use
coefficients.
Abstract
This paper describes the effect of irrigation and ground cover management on crop evapotranspiration
(ET) of young Valencia citrus trees grown on Arredondo fine sand. Six different treatment combinations
were used: three levels of soil water potential and two levels of ground cover condition. Results obtained
with grass cover treatments required 50%o more water than with no grass cover treatments.
Evapotranspiration correlated positively with the amount of irrigation applied. Monthly crop water use
coefficients with grass cover treatments were 50% higher than with no grass cover treatments. Crop water
use coefficient decreased as soil water potential decreased.
PERT-0374-1986
Desiccation and Cryopreservation of Embryonic Axes of Hevea brasiliensis Muell. — Arg.
M.N. Normah, H.F. Chin and Y. L. Hor
Keywords
Cryopreservation; desiccation; embryos; recalcitrant.
Abstract
Hevea embryonic axes were desiccated for a period of1 - 5 hours and the moisture content was determined
at the end of each hour of desiccation. Another set of embryonic axes were aseptically desiccated for the
same period before they were cryopreserved for 16 hours by direct immersion in liquid nitrogen (- 196°C).
At moisture content between 14-20% (desiccation for 2-5 hours), 20 - 69% of the embryonic axes survived
cryopreservation and formed seedlings with normal roots and shoots when cultured in vitro. Abnormalities
were deteched in some seedlings however; hence, refinement of the technique is needed.
PERT-0375-1986
The Impact of Skid Trails on the Physical Properties of Tropical Hill Forest Soils
Kamaruzaman Jusoff and Nik Muhamad Majid
Keywords
Skid trails; physical properties; hill forest soils.
Abstract
Field study was conducted in Sungai Tekam Forest Reserve of Pahang, Malaysia to evaluate the effects of
skid trails on some selected soil properties. Results showed that bulk density and resistance to penetration
increased while total pore space and aeration porosity decreased significantly. The available water holding
capacity returned to normal after two years of exposure. This information is useful to forest and land
managers who are attempting to manage soils to reduce soil compaction and erosion on skid trails and plan
reforestation programmes. Research efforts should aim at reducing the alteration of some soil physical
properties on skid trails by proper harvesting practices and reduction of skid trail related disturbances.
PERT-0376-1986
Classification of Acid Sulfate Soils of Peninsular Malaysia*
S. P A R A M A N A N T H A N and N O O R D I N DAUD Keywords
Classification; acid sulfate soils; Pen. Malaysia.
Abstract
Acid sulfate soils form an important group of soils in Peninsular Malaysia, particularly on the West Coast.
These soils developed over marine, estuarine and brackish water deposits can be divided
into two groups - the potential acid sulfate soils and the true acid sulfate soils using the definitions
established in Soil Taxonomy. The classification of these soils in accordance to the Malaysian system is
discussed. The Malaysian system though based on the concepts of Soil Taxonomy has been modified to
suit local conditions. Two sequences of acid sulfate soils have been recognized in Peninsular Malaysia.
A key to the identification of these acid sulfate soils is also presented in the paper.
PERT-0377-1986
In Vitro Fermentation of Mixed Rumen Microorganisms on
Molasses-based Substrates
NORHANI A B D U L L A H*
Keywords
In vitro fermentation; molasses-urea-protein substrates; r u m e n microorganisms.
Abstract
A fermentor consisting of two compartments (called inner and outer) separated by a dialysis membrane was
developed for studying the digestion pattern in vitro of rumen microorganisms of sheep fed a molasses-urea
based diet. About 35 ml of strained rumen liquor withdrawn from Merino wethers adapted to a molassesurea diet (100 g oaten chaff and molasses containing 5% urea and 0.135%) mineral mix fed ad libitum,)
was used as the initial fermenting inoculum in the inner compartment. Molasses-urea substrate (8.333%)
molasses and 0.277%o urea, w/v) prepared in artificial saliva was infused at 3 ml h'1 into the fermenting
medium and artificial saliva at 30 ml h "1 into the outer compartment. Incubation was carried out in a
specially constructed water bath maintained at 39°C and filled with CO 2gas. With these flow rates, pH
offermenting fluids was maintained within physiological range with volatile fatty acids (VFA) production
at 30 - 40 JJLmole ml 1 h '. Using the fermentor, the effect of partial substitution of tryptone for urea as a
nitrogen source on rumen microorganisms adapted to a molasses-urea based diet was studied with infusion
solution consisting of 8.333%0 molasses, 0.208%) urea and 0.202%o tryptone (w/v) prepared in artificial
saliva. Factors related to cell yield studied were, VFA and ammonia (NH J productions, dry matter (DM)
and CP yields. However, no positive effects of protein supplementation (when compared to molasses-urea
substrate) were observed in VFA productions, DM and CP yields. Only NH} levels of fermentors infused
with molasses-urea substrate were significantly higher (P<i0.05) than protein supplemented fermentors.
PERT-0359-1986
A Study of the Air Quality in Underground Car Parks with Emphasis on Carbon Monoxide and Airborne
M.I. Yaziz and A. W. P. Yen
Keywords
Air pollution; indoor air quality; carbon monoxide; lead.
Abstract
The concentrations of carbon monoxide and airborne lead in three enclosed underground car parks in Kuala
Lumpur were measured simultaneously with traffic flow for a period of three months. The measurements
were taken at a height of 1.5 m from the ground for duration of 8- 13 hours. A large variation in the
airborne lead levels was observed which ranged from 1.75 to 23.9 /Jig/min relation to traffic flow. The
mean carbon monoxide concentration ranged from 23.2 to 65.2 ppm. The mean concentration of both
pollutants at all the three sites was found to exceed the proposed Malaysian Air Quality Standard of 0.7
ug/m3for lead and 9 ppm (8 hours average) for carbon monoxide. A positive correlation was observed
between traffic flow and carbon monoxide as well as lead at the locations studied.
PERT-0360-1986
Diurnal Variations and Frequency Distribution of Air Pollutants Concentration in Kuala Lumpur and its
Outskirts — A Preliminary Analysis
Rikita Inouye and Azman Zainal Abidin
Keywords
Diurnal variations; cumulative frequency distribution.
Abstract
Three continuous air monitoring stations were each installed in Kuala Lumpur, Serdang and Kajang. A
preliminary analysis on the diurnal variations and frequency distribution of the pollutants concentration was
made, using data obtained from 10th. April — 5th. May 1985. The diurnal variations for the primary
pollutants showed two distinct peaks in Kuala Lumpur. These peaks were, however, not clearly defined at
the other sites. Secondary pollutants, on the other hand exhibited normal' diurnal variations at all the sites.
A frequency distribution analysis was also carried out to give a clearer comparison of the pollutants
concentration, among the sites.
PERT-0361-1986
Distribution of Manganese, Iron, Copper, Lead and Zinc in Water and Sediment of Kelang Estuary
A.T. Law and A. Singh
Keywords
Heavy metals; estuary; Malaysia.
Abstract
A study was conducted on the distribution of manganese, iron, copper, lead and zinc in the water and
sediment of Kelang estuary in 1981. The mean total levels of manganese, iron, copper, lead and zinc in the
estuarine water were 27.1ug/1,106.5g/1, 10.0ug/1, 4.1ug/1 and 17.9 ng/1 respectively. For the dissolved
copper, lead and zinc, the values were 4.3ug/l, 1.6txg/1 and 3.9 ug/i respectively. In the estuarine sediment,
the copper, lead and zinc contents were 1.92, 0.48 and 5.43 ppm wet sediment respectively. The levels of
these heavy metals in water and sediment were comparable to the values reported for other estuaries. The
copper and zinc levels were similar to those found in the world oceans. The results indicate that Kelang
estuary is polluted with lead, manganese and iron. However, levels of these heavy metals may still be
considered safe for aquaculture, if the farm is located at least 10 km away from the river mouth.
PERT-0362-1986
Polyphenoloxidase from Starfruit (Averrhoa carambola, L.)
Tengku Adnin Bin Tengku Adnan, M. A. Augustin and Hasanah Mohd. Ghazali
Keywords
Polyphenoloxidase; starfruit; catechol.
Abstract
Polyphenoloxidase (PPO) was isolated from starfruit (Averrhoa carambola, L.) and purified by acetone
precipitation and dialysis. The optimum pH for the acetone purified PPO catalysed oxidation of catechol
was found to be pH 7.2 Heat inactivation studies showed that the enzyme was heat-labile. Half-lives for
PPO inactivation at 70 °C and 75°C were found to be 4.6 min and 3.1 min respectively. The Michaelis
constant (K m) and V max for catechol with PPO was 0.061M and 20 U'ml-2 respectively.
PERT-0363-1986
Taste Panel Evaluation and Acceptance of Soy-beef Burger
Abdul Salam Babji, Aminah Abdullah and Fatimah Yusuf
Keywords
Nutrition; soy protein; beef burger.
Abstract
This study was conducted to investigate the effect of the addition of textured soy protein (TSP) at 0%,
20%), 30%), 40% and 50% levels on the quality and general acceptance of soy-beef burgers by trained taste
panels as well as the consumer. Analyses carried out at three-week intervals include TBA values, water
holding capacity, cooking loss, sensory evaluation and consumer acceptance. The increase of textured soy
protein levels in beef burger resulted in significant decrease in TBA values and cooking loss. The addition
of textured soy protein also increased the water holding capacity of the products. Generally, storage time
reduced the quality of these products. Sensory properties showed that the substitution of meat with textured
soy protein increased the intensity of beany flavour and taste. The addition of textured soy protein
decreased the colour acceptance but had no specific effect on the quality attributes such as appearance,
texture, saltiness and juiciness of the product. Results of the consumer acceptance test showed that there
were no significant differences in preference for the 0%, 20%o and 30%o levels of textured soy protein in
beef burger.
PERT-0364-1986
Alcohol Production from Cassava Starch by Co-immobilized Zymomonas mobilis and Immobilized
Glucoamylase
Y. C. Ho and H.M. Ghazali
Keywords
Zymomonas mobilis; glucoamylase; co-immobilized system.
Abstract
Simultaneous saccharification and fermentation of dextrinized cassava starch to glucose and alcohol,
respectively, were carried out by co-immobilized Zymomonas mobilis and immobilized glucoamylase (IG).
Calcium alginate-entrapped cells and IG (4: 1 ratio) gave an alcohol productivity of 0.30 g/gww cells /h in
a batch fermentation process. For continuous fermentation, 54.3 g/l alcohol was produced at a dilution rate
of 0.3/h. 60% of the initial activity was lost within 3 days and, thereafter; the system entered a slowly
decreasing phase of alcohol production.
PERT-0365-1986
Beberapa Ulasan Baru Tentang Struktur Aljabar Tensor
Shaharir Bin Mohamad ZAIN and Muriati Bte Mukhtar
Keywords
Tensor; isomorfisma; tarikan balik; tolakan ke depan; pengecutan; hasil darab terkedalam; ruang
Riemannan; metrik Riemannan.
Abstract
In the field of classical tensor algebra, there still exist a few concepts that have not been formulated by
using concepts of multilinear algebra and analysis on manifolds. Hence, we have tried to reformulate some
matters that arise in classical tensor analysis and a few others that we had identified and resolved. These
being: the meaning of the equivalence of first order tensor with vector; the pull back and push forward
structure, the structure of contraction of tensors, the inner product term, ds2 as a differential and the
algebraic structure of relative tensors and tensor densities.
PERT-0366-1986
COMMUNICATION I
Optimum Substrate for the Establishment of the Epiphyte Dischidia nummularia (Asclepiadaceae)
Abstract
Brick fragments or wood crumbs (which are substrates with good water retention and aeration) with the
addition of nutrients are optimum substrates for the establishment of seedlings of the epiphytic Dischidia
nummularia. Seeds of D. nummularia, when moistened show 100% germination. Germination is rapid —
the radicle is fully grown within a day and the cotyledons emerge within four to five days. Subsequent
seedling growth, especially for root system development, was better on brick fragments or wood crumbs
than on sand indicating that good water retention and aeration are necessary for seedling establishment.
Within an eight-week period, seedling growth on substrates low in nutrients was slow compared with
substrates where commercial fertiliser was applied in the recommended amount for epiphytic orchids. The
height and number of leaves was roughly doubled and the total dry weight increased between three and
four-fold. Further, with brick fragments as a substrate, addition of nutrients resulted in a more extensive
root system.
PERT-0367-1986
COMMUNICATION II
Growth Characteristics of Lizard Fish (Fam: Synodontidae) in the South China Sea
Abstract
Study of growth characteristics of synodontids of Malaysia was carried out in waters within the Exclusive
Economic Zone, South China Sea. Five age groups were identified for Saurida tumbil and four for S.
undosquamis. Growth parameters of the von Bertalanffy equation for the two species are presented.
PERT-0368-1986
COMMUNICATION III
Isolation of Pasteurella haemolytica from the Spleen of Chickens
Abstract
Pasteurella haemolytica was isolated from eight spleens of chickens with white focal lesions. A
pathogenicity study in chickens did not reveal any significant findings.