Preliminary Studies on the Performance of Landrace, Duroc and Their Crossbreds in a Tropical

Pertanika Vol. 1 No. 2 December 1978

PERT-0011-1978

Preliminary Studies on the Performance of Landrace, Duroc and their Crossbreds in a Tropical Environment

K. K. Kuan and T. K. Mak

Keywords

Pigs, Performance, Repeatability

Summary

A study on the performance of pigs at the Pig Unit, UniversitiPertanian Malaysia, was made. The birth weight per pigling of Landrace-Duroc crossbreds was significantly higher (P<0.01) than the mean of the parental breeds in the first and second farrowing. The crossbreds also showed general improvement in litter size at birth, litter size at weaning, weaning weight, age at first estrus and age at first farrowing. The only exception was the weaning weight at second farrowing in the crossbreds where their performance was lower than the purebreds. This could be attributed to a change of feed. Repeatability estimates of 0.1461 and 0.2416 for litter size at birth in Landrace and Duroc were obtained.

PERT-0012-1978

Pupal Distribution of DacusdorsalisHendel in Relation to Host Plants and its Pupation Depth

Yusof Ibrahim and RosliMohamad

Keywords

Fruit fly DacusdorsalisHendel; Pupal Distribution; Pupation depth

Summary

Studies on pupal distribution of DacusdorsalisHendel in relation to host plants and its depth of pupation were conducted. Samples from papaya trees gave significantly (P<0.05) higher pupal count compared to those from guava, starfruit, and jackfruit. No significant differences were obtained among samples from the latter three host plants. The pupae were also found to be almost evenly distributed under the trees. The results obtained also showed that this insect prefers to pupate at 2 cm and 3 cm soil depth.

PERT-0013-1978

Observations on Growth and early Production of some Durian (DuriozibethinusMurr) Clones at UniversitiPertanian Malaysia Orchard

Othman Yaacob, mohd. Noor Ismail and AwaluddinHajiTalib

Keywords

Durian growth, Early yield, Research needs

Summary

The establishment of a 22 acre durian orchard on an oxisol soil formerly under old rubber is recorded outlining the nature of the environment and the cultural practices adopted since 1969. The growth pattern of all clones planted, early flowering and fruiting patterns are also discussed together with possible causes of poor fruiting habits of D2 and D96. Some possible areas for research are suggested for future work based on these observations.

PERT-0014-1978

Evaluation of Some Long Bean Lines Using Early and Late Produced Seeds in Two Soil Types

T. C. Yap and K. T. Cheok

Keywords

Long bean lines, Soil types, Early and Late produced seeds

Summary

Early and late produced seeds of some F9 lines and exotic cultivars of long beans were evaluated on clayey loam and alluvial soil in the University Farm at Serdang. The results showed that pod yield and pod length were not significantly different for seeds produced early or late. Among the genotypes studied, pod yield was more unstable than pod length. However, some lines and Taiwan Stripe Seed performed better than the local commercial variety, Local Long-1 in both soil type.

PERT-0015-1978

Tanda-tandaGenetikOrangAslidanBangsa-BangsaBumiputera Sabah, Sarawak dan Brunei. Kumpulan-kumpulandarahdalamtigabangsaterbesardi Malaysia danSingapura: Suatupenyusunan data

S. G. Tan

Keywords

Blood groups, Biochemical Genetic Markers, Main Races, Aborigines, Indigenous Races, Malaysia, Singapore, Brunei

Summary

Suatusenarai data berkenaandengankumpulan-kumpulandarahuntukorang-orangMelayu, China dan India (tigabangsaterbesardi Malaysia danSingapura) danjugauntukOrangAslidariSemenanjung Malaysia danBangsa-BangsaBumiputeradari Sabah, Sarawak dan Brunei, telahdisusundarisasterasains. Data untuktanda-tandagenetikbiokimiadalamOrangAslidariSemenanjung Malaysia danBangsa-BangsaBumiputeradari Sabah, Sarawak dan Brunei pun telahdisusun.Tarafadanya data genetikuntukbangsabangsatersebutdanprospekuntukpengkajianpadamasahadapantelahdibincangkan.Kertasinimenyempurnakansuatupercubaan (dalamduabahagian) untukmenyusunsemua data yang adapadamasasekarangberkenaandengantanda-tandagenetikdalampenduduk-penduduk Malaysia danSingapura.

PERT-0016-1978

Effects of Selection for High Litter-Weight on Reproductive Performance in Mice

K. Baharin and R. G. Beilharz

Keywords

Reproductive Performance, Mice, Litter-weight, Selection, Inbreeding

Summary

The reproductive performances of two lines of mice selected for high litter-weight at nine weeks of age and a control line were compared based on data obtained after 15 generations of breeding. Twenty pairs of parents were bred per generation in the control line and ten pairs in each of the selected lines. At each generation the parents were mated only once. Calculation of inbreeding coefficients from pedigrees indicated a rapid rise in inbreeding coefficient in the selected lines. There was little response to selection for high litter-weight and in fact there was a general decline in reproductive performance associated with high levels of inbreeding in the selected lines although the relationship was not linear. Some initial response in bodyweight gain was observed but even this trait showed a decline in later generations when inbreeding coefficient exceeded 40%.

PERT-0017-1978

Tax Burden on Rubber, Coconut and Pineapple Smallholders in Johore

Mohammed Ariff Bin Hussein

Keywords

Durian growth, Early yield, Research needs

Summary

The study examines whether taxes levied on rubber, coconut, and pineapple smallholders in 1975 are a major cause for smallholder low income. Results of the study show that tax burden on the smallholder is substantial, particularly that on rubber smallholders. The average rubber smallholder pays about one-fourth to one third of his income in taxes. However, the scope for increasing income through changes in the tax structure is limited. Such changes should be coupled with programmes aimed at increasing farm productivity and size of holding.

PERT-0018-1978

Floristic Components of the Ground Flora of a Tropical Lowland Rain Forest at GunungMulu National Park, Sarawak

Ruth Kiew

Keywords

Floristic Components, Ground Layer, Lowland rainforest, Microhabitat, Distribution of tropical Herbaceous plants, Variegated foliage

Summary

The floristic components of the ground layer at the GunungMulu National Park, Sarawak, are described. These components are associated with microhabitats. The microhabitats of the riverine system include the shallow stream, rocky banks and banks of larger rivers, and those of the shaded forest include permanently wet areas, rocky litter-free slopes, steep litter covered slopes, surfaces of logs, roots or rocks and the flat well-drained alluvial forest. Possible causes of the uneven distribution of the ground layer species of the flat well-drained alluvial forest are discussed. The species composition of this alluvial forest is compared with other published reports from the Danum Valley, Sabah and Pasoh Forest Reserve Malaya, and with some other lowland forest types such as kerangas and peat swamp forest in Sarawak. The phenomenon of iridescence and variegation of leaves is briefly noted.

PERT-0019-1978

Leg Paralysis Inducement by Risella 17 Oil in Luciliasericata (Meig) as Affected by Sex, Time, Application Site, and Oil Volume

G. S. Lim

Keywords

Risella 17 Oil; Luciliasericata (Meig); Leg Paralytic Induction, England

Summary

Development of leg paralysis induced by Risella 17 oil on Luciliasericata (Meig.) was found to be significantly affected by sex, time, application site, and oil volume. Male flies were noted to be more susceptible than female flies. In both sexes, more were affected at a given time when a greater volume of oil was applied. The PV50 (volume of oil required to induce paralytic symptoms in 50% of the treated flies) was found to be 0.13 µl for the male flies, and 0.2 µl for the female flies. Their probit regression lines are: y = 4.01x + 0.57 for the male, and y =s 2.64x + 1.35 for the female. The number of male flies that developed leg paralysis was dependent on the site of application. With 0.3 µl of oil, there were about twice as many flies affected in treatment on the abdomen as compared to that on the thorax. However, no significant difference was observed between applications made dorsally and ventrally on the abdomen. Flies treated on the head and legs did not develop any paralytic symptoms. The findings suggest that there is more than one mode of action. However, the relative importance and role of any mode of action in contributing to the paralysis inducement with subsequent death, would require further and more critical investigations.

PERT-0020-1978

Progress of Natural Regeneration after Final Felling under the Current Silvicultural Practices in Matang Mangrove Reserve

P. B. L. Srivastava and DaudKhamis

Keywords

Mangrove, Natural Regeneration

Summary

The paper presents the results of an investigation on the progress of regeneration of mangrove forests after logging with emphasis on species composition, distribution pattern and stocking. The investigation was undertaken in the Port Weld Range of The Matang Mangrove Reserve. The areas chosen belong to inundation classes III and IV (Watson, 1928) representing a typical Rhizophora type. Two age classes, i.e. 12 months and 24 months after felling, were sampled by means of Linear Regeneration Sampling (LRS 1) method. Rhizophora spp. and Bruguiereparviflora were the most important species in the residual stands with 3701 and 3376 seedlings per acre of Rhizophora spp. respectively in the areas 12 and 24 month after final felling. There was a significant decrease in the number of B. parviflora seedlings in the areas 24 months after felling with only 62 seedlings per acre compared to 1282 seedlings per acre, 12 months after felling. There was no large scale mortality in the Rhizophora seedlings with time during this period. At both the age classes, the areas had enough number of seedlings to produce a fully stocked stand at the end of rotation if no large scale mortality occurred.

PERT-0021-1978

Mineralogy and Related Properties of Acid Sulphate Soil from Melaka, Peninsular Malaysia

ShamsuddinJusop and Tuan Omar Raja Senik

Keywords

Acid Sulphate, Montmorillonite, Pyrite

Summary

Mineralogical, chemical and physical properties of acid sulphate soil from Kuala Linggi, Melaka, were studied. The study shows that the soil contains kaolinite, montmorillonite, illite, chlorite and pyrite. There are no mineralogical differences between the top and the lower horizons. Both total sulphate and water-soluble sulphate increase with depth. The CEC of the soil is above 16m/l00g soil, probably due to the presence of montmorillonite. However, the presence of pyrite, which is easily oxidizable to acid sulphate on exposure, makes the soil less suitable for agricultural purposes.

PERT-0022-1978

KesanNukleotiddanNukleosidterhadapAktivitiFosfodiesteraseMycobacterium smegmatis

C.H. Lee

Introduction

The inhibitory effect of ATP on phosphodiesterase activity plays an important regulatory role in animal cells (Cheung, 1966), but this condition has not been demonstrated in micro-organisms. This communication shows the inhibitory effect of ATP and other purine and pyrimidinetrinucleotides on phosphodiesterase activity in Mycobacterium smegmatis. Although trinucleotides inhibit phosphodiesterase activity, mononucleotides or adenosine stimulate enzyme activity. The results from this study suggest that the intracellular concentration of cyclic AMP is influenced by nucleotides, nucleosides and deoxynucleotides.