Displaying publications 61 - 80 of 119 in total

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  1. Fulltext Development of Photovoltaic Module with Fabricated and Evaluated Novel Backsheet-Based Biocomposite Materials
    Alaaeddin MH, Sapuan SM, Zuhri MYM, Zainudin ES, M Al-Oqla F
    Materials (Basel), 2019 Sep 17;12(18).
    PMID: 31533207 DOI: 10.3390/ma12183007
    Photovoltaic backsheets have considerable impact on the collective performance of solar cells. Material components should withstand certain temperatures and loads while maintaining high thermal stability under various weather conditions. Solar modules must demonstrate increased reliability, adequate performance, safety, and durability throughout the course of their lifetime. This work presents a novel solar module. The module consists of an innovative polyvinylidene fluoride-short sugar palm fiber (PVDF-SSPF) composite backsheet within its structure. It was electrically and thermally evaluated. The current-voltage characteristics (I-V) were obtained using the solar module analyzer, PROVA 210PV. A thermal evaluation was accomplished using a temperature device, SDL200. The thermal test consisted of two different assessments. The first targeted the surface and backsheet of the developed module to correlate their performance from within. The second assessment compared the thermal performance of the fabricated backsheet with the conventional one. Both tests were combined into a heatmap analysis to further understand the thermal performance. Results revealed that the developed module exhibited reasonable electrical efficiency, achieving appropriate and balanced I-V curves. PVDF-SSPF backsheets proved to be thermally stable by displaying less heat absorbance and better temperature shifts. Additional research efforts are highly encouraged to investigate other characteristics. To enhance performance, further analyses are needed such as the damp heat analysis, accelerated aging analysis, and heat dissipation phenomena.
    Matched MeSH terms: Weather
  2. Developing correlation equations for converting among coliforms, E. coli and HPC for rainwater disinfection by sunlight
    M.T. Amin, M.Y. Han, Tschung-il Kim, A.A. Alazba, M.N. Amin
    Sains Malaysiana, 2013;42:1273-1281.
    The application of solar disinfection for treating stored rainwater was investigated by the authors using indicator organisms. The multiple tube fermentation technique and pour plate method were used for the detection of microbial quality indicators like total and fecal coliforms, E. coli and heterotrophic plate count. These techniques have disadvantages mainly that these are laborious and time consuming. The correlation of total coliform with that of exposure time is proposed under different factors of weather, pH and turbidity. Statistical tools like root mean square error and coefficient of determination were used to validate these proposed equations. The correlation equations of fecal coliform, E. coli and heterotrophic plate count with total coliform are suggested by using four regression analysis including Reciprocal Quadratic, Polynomial Regression (2 degree), Gaussian Model and Linear Regression in order to reduce the tedious experimental work in similar types of experiments and treatment systems.
    Matched MeSH terms: Weather
  3. Fulltext IoT-Based Sensor Data Fusion for Determining Optimality Degrees of Microclimate Parameters in Commercial Greenhouse Production of Tomato
    Rezvani SM, Abyaneh HZ, Shamshiri RR, Balasundram SK, Dworak V, Goodarzi M, et al.
    Sensors (Basel), 2020 Nov 12;20(22).
    PMID: 33198414 DOI: 10.3390/s20226474
    Optimum microclimate parameters, including air temperature (T), relative humidity (RH) and vapor pressure deficit (VPD) that are uniformly distributed inside greenhouse crop production systems are essential to prevent yield loss and fruit quality. The objective of this research was to determine the spatial and temporal variations in the microclimate data of a commercial greenhouse with tomato plants located in the mid-west of Iran. For this purpose, wireless sensor data fusion was incorporated with a membership function model called Optimality Degree (OptDeg) for real-time monitoring and dynamic assessment of T, RH and VPD in different light conditions and growth stages of tomato. This approach allows growers to have a simultaneous projection of raw data into a normalized index between 0 and 1. Custom-built hardware and software based on the concept of the Internet-of-Things, including Low-Power Wide-Area Network (LoRaWAN) transmitter nodes, a multi-channel LoRaWAN gateway and a web-based data monitoring dashboard were used for data collection, data processing and monitoring. The experimental approach consisted of the collection of meteorological data from the external environment by means of a weather station and via a grid of 20 wireless sensor nodes distributed in two horizontal planes at two different heights inside the greenhouse. Offline data processing for sensors calibration and model validation was carried in multiple MATLAB Simulink blocks. Preliminary results revealed a significant deviation of the microclimate parameters from optimal growth conditions for tomato cultivation due to the inaccurate timer-based heating and cooling control systems used in the greenhouse. The mean OptDeg of T, RH and VPD were 0.67, 0.94, 0.94 in January, 0.45, 0.36, 0.42 in June and 0.44, 0.0, 0.12 in July, respectively. An in-depth analysis of data revealed that averaged OptDeg values, as well as their spatial variations in the horizontal profile were closer to the plants' comfort zone in the cold season as compared with those in the warm season. This was attributed to the use of heating systems in the cold season and the lack of automated cooling devices in the warm season. This study confirmed the applicability of using IoT sensors for real-time model-based assessment of greenhouse microclimate on a commercial scale. The presented IoT sensor node and the Simulink model provide growers with a better insight into interpreting crop growth environment. The outcome of this research contributes to the improvement of closed-field cultivation of tomato by providing an integrated decision-making framework that explores microclimate variation at different growth stages in the production season.
    Matched MeSH terms: Weather
  4. Fulltext Microclimatic performance of courtyard residential buildings in Kafanchan-Nigeria
    Markus Bulus, Lim, Yaik-Wah, Malsiah Hamid
    Journal of Advanced Research Design, 2017;37(1):16-25.
    MyJurnal
    The Climatic performance of courtyard residential buildings needs to be
    investigated if the assertion that courtyard is a microclimate modifier is to be
    accepted. Therefore, this study seeks to examine the microclimatic performance
    of two existing courtyard residential buildings with similar characteristics in
    Kafanchan-Kaduna Nigeria, -the fully enclosed courtyard residential building and
    the semi-enclosed courtyard residential building. The purpose of this research is
    to investigate their microclimatic performances in other to establish the best
    courtyard house. This study uses measurement to achieve its aim. The tool
    employed for data collection is the Hobo Weather Data Loggers (HWDL). Three
    HWDL were used to collect data in the two case-study, and the third one was
    placed in the outside area as a benchmark. Only air temperature and relative
    humidity were measured. This study revealed a tangible difference in the
    microclimatic performance of the two case-study. The fully enclosed courtyard
    residential building is seen to have air temperature difference of 1 oC to 3 oC, and
    the relative humidity difference of 4 % to 8 %. In conclusion, the fully enclosed
    courtyard house demonstrated a more favorable microclimatic performance than
    the semi-enclosed, and further simulation studies towards its optimization are
    required.
    Matched MeSH terms: Weather
  5. Fulltext A study on the microclimatic performance of courtyard and non-courtyard residential buildings in hot-arid climate
    Markus Bulus, Lim, Yaik-Wah, Malsiah Hamid
    Journal of Advanced Research in Applied Sciences and Engineering Technology, 2017;9(1):1-13.
    MyJurnal
    Scholars have opined that the courtyard is a passive architectural design element and
    that it can act as a microclimate modifier provided that its design requirements are not
    ignored. But despite the assertions, empirical studies on the microclimatic
    performance of a fully enclosed courtyard house and the non-courtyard house seems
    to be deficient, and the assumption that the Courtyard is a passive architectural design
    element needs to be substantiated. Therefore, the purpose of this study is to
    investigate the microclimatic performance of a fully enclosed courtyard and noncourtyard
    residential buildings. The main objective is to compare their microclimatic
    performances in other to draw a conclusion on the best option. Three Hobo Weather
    Data Loggers were used to collect climatic data in the buildings, and the third one was
    situated in the outdoor area as a benchmark. The climatic variables investigated are;
    air temperature and relative humidity. The fully enclosed courtyard residential building
    is seen to have a better air temperature difference of 2 oC to 4 oC and the relative
    humidity of 2 % to 6 %. In conclusion, the fully enclosed courtyard residential building
    has confirmed a more favorable microclimatic performance, and future studies
    towards its optimization are recommended.
    Matched MeSH terms: Weather
  6. The effects of rainfall on trombiculid (Acarina:trombiculidae) larval populations in peninsular Malaysia
    Gentry JW, Phang OW, Manikumaran C
    Southeast Asian J. Trop. Med. Public Health, 1977 Jun;8(2):217-20.
    PMID: 918713
    Studies of larval mite populations along transects, as measured with black plates, were conducted in forest and grassland habitats for a period of 67 weeks. Larvae of both Leptotrombidium (Leptotrombidium) deliense and L. (L.) fletcheri were influenced greatly by rainfall, with the larvae being abundant and easily collected during periods of heavy rainfall and difficult or impossible to collect during dry periods. Simulated rainfall maintained larval populations for longer periods during dry weather.
    Matched MeSH terms: Weather*
  7. The persistence of naturally formed mit (Acarina: trombiculidae) foci in Malaysia
    Gentry JW, Phang OW, Manikumaran C
    Southeast Asian J. Trop. Med. Public Health, 1977 Jun;8(2):214-6.
    PMID: 918712
    Mite foci were fenced above and below ground to prevent the entry of host animals and to prevent the migration of mites within the soil. Weekly counts were made over a period of thirty weeks with larvae being collected at the beginning and end of the study, but not during the intervening period of hot, dry weather. Post-larval forms can survive for long periods and mite foci can remain productive without being visited by the host animals. Mite foci may be missed by normal survey methods during hot, dry weather.
    Matched MeSH terms: Weather
  8. Fulltext Total electron content forecasting using artificial neural network
    Rohaida Mat Akir, Kalaivani Chellappan, Mardina Abdullah
    Pertanika Journal of Science & Technology, 2017;25(106):19-28.
    MyJurnal
    Space weather forecasting and its importance for the power and communication industry have inspired research related to TEC forecasting lately. Research has attempted to establish an empirical model approach for TEC prediction. In this paper, artificial neural networks (ANNs) have been applied in total electron content using GPS Ionospheric Scintillation and TEC Monitor (GISTM) data from UKM Station. The TEC prediction will be useful in improving the quality of current GNSS applications, such as in automobiles, road mapping, location-based advertising, personal navigation or logistics. Hence, a neural network model was designed with relevant features and customised parameters. Various types of input data and data representations from the ionospheric activity were used for the chosen network structure, which was a three-layer perceptron trained by feed forward back propagation method and tested on the chosen test data. We found that the optimum RMSE occurred with 10 nodes as the best NN for GISTM UKM station for the studied period with RMSE 1.3457 TECU. An analysis was made to compare the TEC from the measured TEC with neural network prediction and from IRI-corr model. The results showed that the NN model forecast the TEC values close to the measured TEC values with 9.96% of relative error. Thus, the forecasting of total electron content has the potential to be implemented successfully with larger data set from multi-centred environment.
    Matched MeSH terms: Weather
  9. Experimental Amelioration of Harsh Weather Speeds Growth and Development in a Tropical Montane Songbird
    Mitchell AE, Boersma J, Anthony A, Kitayama K, Martin TE
    Am Nat, 2020 10;196(4):E110-E118.
    PMID: 32970467 DOI: 10.1086/710151
    AbstractOrganisms living at high elevations generally grow and develop more slowly than those at lower elevations. Slow montane ontogeny is thought to be an evolved adaptation to harsh environments that improves juvenile quality via physiological trade-offs. However, slower montane ontogeny may also reflect proximate influences of harsh weather on parental care and offspring development. We experimentally heated and protected nests from rain to ameliorate harsh montane weather conditions for mountain blackeyes (Chlorocharis emiliae), a montane songbird living at approximately 3,200 m asl in Malaysian Borneo. This experiment was designed to test whether cold and wet montane conditions contribute to parental care and postnatal growth and development rates at high elevations. We found that parents increased provisioning and reduced time spent warming offspring, which grew faster and departed the nest earlier compared with offspring from unmanipulated nests. Earlier departure reduces time-dependent predation risk, benefitting parents and offspring. These plastic responses highlight the importance of proximate weather contributions to broad patterns of montane ontogeny and parental care.
    Matched MeSH terms: Weather*
  10. Fulltext Data Assessment on the relationship between typical weather data and electricity consumption of academic building in Melaka
    Ngah Nasaruddin A, Tee BT, Mohd Tahir M, Md Jasman MES
    Data Brief, 2021 Apr;35:106797.
    PMID: 33614870 DOI: 10.1016/j.dib.2021.106797
    Exposure to hot and humid weather conditions will often lead to consuming a vast amount of electricity for cooling. Heating, ventilation, and air conditioning (HVAC) systems are customarily known as the largest consumers of energy in institutions and other facilities which raises the question regarding the impact of the weather conditions to the amount energy consumed. The academic building is a perfect example where a constant fixed daily operating characteristic is measured by the hour, aside from the occasional semester break. Therefore, it can be assumed that the daily HVAC services on an academic facility will operate on a fixed schedule each day, having a similar pattern all year round. This article aims to present an analysis on the relationship between typical weather data by implying the test reference year (TRY) and academic building electricity consumption in an academic building located at Durian Tunggal, Melaka. Typical weather data were generated in representing the weather data between 2010 and 2018 using the Finkelstein-Schafer statistic (F-S statistic) in addition to a data set of electricity consumption. Descriptive analysis and correlation matrix analysis were conducted using JASP software for two sets of sample data; Set A and Set B, with data points of 12 and 108, respectively. The result showed an alternate result with a positive correlation between 1)mean temperature-electricity consumption, and 2)mean rainfall-electricity consumption for data Set A, and a negative correlation between 1)mean temperature-electricity consumption and 2)mean rainfall-electricity consumption for data Set B.
    Matched MeSH terms: Weather
  11. Fulltext Household survey of container-breeding mosquitoes and climatic factors influencing the prevalence of Aedes aegypti (Diptera: Culicidae) in Makkah City, Saudi Arabia
    Aziz AT, Dieng H, Ahmad AH, Mahyoub JA, Turkistani AM, Mesed H, et al.
    Asian Pac J Trop Biomed, 2012 Nov;2(11):849-57.
    PMID: 23569860 DOI: 10.1016/S2221-1691(12)60242-1
    To investigate the prevalence of container breeding mosquitoes with emphasis on the seasonality and larval habitats of Aedes aegypti (Ae. aegypti) in Makkah City, adjoining an environmental monitoring and dengue incidence.
    Matched MeSH terms: Weather*
  12. Fulltext Incidence, risk factors and clinical epidemiology of melioidosis: a complex socio-ecological emerging infectious disease in the Alor Setar region of Kedah, Malaysia
    Hassan MR, Pani SP, Peng NP, Voralu K, Vijayalakshmi N, Mehanderkar R, et al.
    BMC Infect Dis, 2010;10:302.
    PMID: 20964837 DOI: 10.1186/1471-2334-10-302
    Melioidosis, a severe and fatal infectious disease caused by Burkholderia pseudomallei, is believed to an emerging global threat. However, data on the natural history, risk factors, and geographic epidemiology of the disease are still limited.
    Matched MeSH terms: Weather
  13. Fulltext Simple modification measurement of photodegradability of polymers by using photo-induced chemiluminescence technique
    Siti Farhana Zakaria, Millington, Keith R.
    Scientific Research Journal, 2013;10(2):0-0.
    MyJurnal
    Polymers and organic materials that are exposed to sunlight undergo photooxidation, which leads to deterioration of their physical properties. To allow adequate performance under outdoor conditions, synthetic polymers require additives such as antioxidants and UV absorbers. A major problem with optimising polymer formulations to maximise their working life span is that accelerated weathering tests are empirical. The conditions differ significantly from real weathering situations, and samples require lengthy irradiation period. Degradation may not be apparent in the early stages of exposure, although this is when products such as hydroperoxides are formed which later cause acceleration of oxidation. A simple way of quantifying the number of free radicals presents in organic materials following exposure to light or heat is by measuring chemiluminescence (CL) emission. Most polymers emit CL when they undergo oxidative degradation, and it originates from the bimolecular reaction of macroperoxy radicals which creates an excited carbonyl.
    Matched MeSH terms: Weather
  14. Fulltext Analysis of air humidity and temperature for post lightning circumstances
    Sharifah Sakinah, Tuan Othman, Jasronita, Jasni, Mohd Nazim, Mohtar
    Pertanika Journal of Science & Technology, 2017;25(102):79-86.
    MyJurnal
    Lightning is a natural phenomenon that generates a high electric field during thunderstorm. It has been
    reported that lightning strikes amid storms can occur around 100 times per second. The atmospheric
    electric field is an imperative parameter during a thunderstorm. Therefore, monitoring the electric field
    and its parameters is the best way for local lightning forecast. The electric field monitoring data can
    validate the accuracy of weather prediction in a local area from meteorology department or by using
    equipment specially designed to measure this electric field that exists when the phenomenon of lightning occurs. In this paper, the relationship between lightning, air humidity and temperature is discussed to understand the post lightning effect on these electric parameters. Additionally, the characteristics of the parameters are observed and analysed.
    Matched MeSH terms: Weather
  15. The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate
    Watts N, Amann M, Arnell N, Ayeb-Karlsson S, Belesova K, Boykoff M, et al.
    Lancet, 2019 11 16;394(10211):1836-1878.
    PMID: 31733928 DOI: 10.1016/S0140-6736(19)32596-6
    Matched MeSH terms: Weather
  16. Influence of Weather on Hardness and Surface Roughness of Maxillofacial Elastomeric Materials
    Mousa MA
    J Contemp Dent Pract, 2020 Jun 01;21(6):678-682.
    PMID: 33025938
    AIMS: The purpose of this study was to assess the influence of hot and dry weather on the hardness and surface roughness of four different maxillofacial silicone elastomeric materials (MFSEM) including two room-temperature vulcanized (RTV) and two high-temperature vulcanized (HTV) materials.

    MATERIALS AND METHODS: Eighty test specimens were fabricated according to the manufacturer's instructions into rectangular test specimens. The hardness and surface roughness were tested, after 6 months of exposure to natural hot and dry weather. The hardness was measured through the International Rubber Hardness Degree (IRHD) scale using an automated hardness tester. The surface roughness was measured using a novel 3D optical noncontact technique using a combination of a light sectioning microscope and a computer vision system. Statistical Package for Social Sciences software SPSS/version 24 was used for analysis and a comparison between two independent variables was done using an independent t test, while more than two variables were analyzed, F test (ANOVA) to be used followed by a post hoc test to determine the level of significance between every two groups.

    RESULTS: The hot and dry weather statistically influenced the hardness and surface roughness of MFSEM. Cosmesil M-511 showed the least hardness in test groups while A-2000 showed the hardest material (p < 0.05). A-2000 showed significant changes from rough in case of nonweathered to become smoother in weather followed by A-2186 (p < 0.05). Cosmesil M-511 showed the roughest material.

    CONCLUSION: Cosmesil M-511 showed the least hard MFSEM after outdoor weathering while A-2000, the highest and least material showed hardness and surface roughness, respectively.

    CLINICAL IMPLICATION: A-2000 had a high IRHD scale hardness. This makes this material more suitable for the replacement of ear and nose defects. Cosmesil M-511 is soft and easily adaptable material that makes the material more appropriate for the replacement of small facial defect with undercut area to be easily inserted and removed. Whilst A-2000 is smoother and finer in test specimens after weathering, Cosmesil M-511 became rougher after weathering.

    Matched MeSH terms: Weather
  17. Fulltext Evaluation of factors influencing the groundwater chemistry in a small tropical island of Malaysia
    Kura NU, Ramli MF, Sulaiman WN, Ibrahim S, Aris AZ, Mustapha A
    Int J Environ Res Public Health, 2013 May;10(5):1861-81.
    PMID: 23648442 DOI: 10.3390/ijerph10051861
    Groundwater chemistry of small tropical islands is influenced by many factors, such as recharge, weathering and seawater intrusion, among others, which interact with each other in a very complex way. In this work, multivariate statistical analysis was used to evaluate the factors controlling the groundwater chemistry of Kapas Island (Malaysia). Principal component analysis (PCA) was applied to 17 hydrochemical parameters from 108 groundwater samples obtained from 18 sampling sites. PCA extracted four PCs, namely seawater intrusion, redox reaction, anthropogenic pollution and weather factors, which collectively were responsible for more than 87% of the total variance of the island's hydrochemistry. The cluster analysis indicated that three factors (weather, redox reaction and seawater intrusion) controlled the hydrochemistry of the area, and the variables were allocated to three groups based on similarity. A Piper diagram classified the island's water types into Ca-HCO3 water type, Na-HCO3 water type, Na-SO4-Cl water type and Na-Cl water type, indicating recharge, mixed, weathering and leached from sewage and seawater intrusion, respectively. This work will provide policy makers and land managers with knowledge of the precise water quality problems affecting the island and can also serve as a guide for hydrochemistry assessments of other islands that share similar characteristics with the island in question.
    Matched MeSH terms: Weather
  18. Fulltext Wetting/Drying Behavior of Lime and Alkaline Activation Stabilized Marine Clay Reinforced with Modified Coir Fiber
    Kamaruddin FA, Anggraini V, Kim Huat B, Nahazanan H
    Materials (Basel), 2020 Jun 17;13(12).
    PMID: 32560432 DOI: 10.3390/ma13122753
    The durability of natural and treated clay soil stabilized with lime and alkaline activation (AA) affected by environmental factors (hot and humid) was determined in this study. Investigation and evaluation on the strength of the soil, moisture content, and volume change of the specimen were determined at each curing period (7, 28, and 90 days) based on the weather conditions. An unconfined compressive strength (UCS) of the specimen at three different wetting/drying cycles (one, three, and five cycles) was determined. The findings show that the strength of the treated specimens fluctuated with increment and decrement strength (one and three cycles) in the range of 1.41 to 1.88 MPa (lime) and 2.64 to 8.29 MPa (AA), while for five cycles with a curing period of 90 days the decrement was in the range of 1.62 to 1.25 MPa and 6.06 to 5.89 MPa for lime and AA, respectively. The decrement percentage for treated samples that were subjected to five cycles of wetting and drying in 90 days was found to be 20.38% (lime) and 38.64% (AA), respectively. Therefore, it can be summarized that wetting/drying cycles have a significant influence on the durability, strength, and the volume changes of the specimens.
    Matched MeSH terms: Weather
  19. Fulltext Motivators and barriers of physical activity among private office workers in Selangor
    Nui Jia Jun, Khairil Shazmin Kamarudin, Asma Ali, Noor Salihah Zakaria
    Malaysian Journal of Medicine and Health Sciences, 2020;16(1):58-65.
    MyJurnal
    Introduction: In Malaysia, private office workers tend to be more physically inactive due to work burden. This study aimed to determine physical activity level, motivation factors and barrier towards physical activity among private office workers. Methods: A cross sectional study using convenience sampling was conducted at nine private com- panies in Selangor involving 106 office workers aged 21 to 55 years old. Self-administered questionnaires includ- ing Global Physical Activity Questionnaire (GPAQ), Physical Activity and Leisure Motivation Scale (PALMS) and Physical Activity Barrier (PAB) were administered. Results: Over half of the respondents (58.5%) were having low physical activity level. The main motivation factors include physical condition, psychological condition and mastery. Meanwhile, tired after work, laziness, lack of discipline, family commitment and adverse weather were the main perceived barriers. A weak positive correlation was found between total motivation score and total physical activity (r=0.296; p=0.002). In contrast, there was a weak negative correlation between barriers and total physical activity (r=-0.237; p=0.015). Conclusion: The current physical activity level, its main motivation factors and barriers among private office workers were identified, providing an opportunity to create effective setting-based health promotion and intervention. It is also recommended that policy suggestions are made to influence and prepare essential partners (e.g. companies and employees) to promote ways of incorporating physical activity into one’s daily routine.
    Matched MeSH terms: Weather
  20. Biological Control of Diamondback Moth, Plutella xylostella (L.),Using Parasitoids and Bacteria: A Review
    Idris A.B., Norhayati Abdul Mukti
    Sains Malaysiana, 1997;26.
    Resistance of diamondback moth (DBM), Plutella xylostela (L), to coventional pesticides and concerns about environmental quality have lead to increased worldwide efforts to develop viable biocontrol methods for DBM. The success of using parasitoids, especially larval parasitoids like Diadegma, Cotesia and Microplitis species for controlling DBM have been reported in several countries. These larval parasitoids of DBM are commonly found in the field. Diadegma semiclausum (=eucerophaga) Hellen is the major parasitoid of DBM in Europe and Asia, while Diadegma insulare (Cresson) are predominates in the Americas. To date, the bacterium, Bacillus thuringiensis Berliner subspecies kurstaki, has been the most widely used DBM pathogen. Although it is environment friendly pesticides, its effectiveness always vary with weather, field location and frequency of application per season. These are the main factors that contribute to the slow acceptance of B.thuringiensis by the cabbage growers worldwide. Because of this many studies have been done to improve its efficacay and persistence in the field. This paper provides an overview of the current status of these agents for use in controlling DBM and suggest research that is needed to improve the usefulness of these biocontrol agents and to maximize their impact on the DBM management in the future.
    Ketahanan rama-rama belakang-intan (diamondback moth), Plutella xylostella (L.), kepada semua racun-racun perosak yang biasa digunakan untuk mengawalnya dan keprihatinan terhadap kualiti alam sekitar telah menyebabkan bertambahnya usaha mencari beberapa kaedah kawalan biologi rama-rama ini di seluruh dunia. Kejayaan menggunakan parasitoids, terutamanya parasitoid larva seperti spesies Diadegma, Cotesia dan Microplitis bagi kawalan serangga ini telah dilaporkan oleh beberapa negara. Parasitoid-parasitoid larva ini mudah didapati di lapangan. Diadegma semiclausum (=eucerophaga) Hellen adalah merupakan parasitoid utama di Eropah dan Asia, sementara Diadegma insulare (Cresson) predominen di benua America. Sehingga kini, bakteria Bacillus thuringiensis Berliner subspesies kurstaki, adalah sejenis patogen serangga yang digunakan secara meluas untuk mengawal rama-rama tersebut. Walaupun B. thuringiensis adalah sejenis racun makhluk perosak yang tidak mencemari alam sekitar, tahap keberkesanan tindakannya adalah kerap berubah-ubah mengikut perubahan cuaca, lokasi lapangan dan kekerapan penggunaannya. Ini adalah merupakan faktor-faktor penting yang menyebabkan kelambatan penerimaannya oleh penanam-penanam kobis di merata dunia. Oleh sebab inilah banyak kajian telah dan sedang dijalankan bagi memperbaiki tahap keberkesanan dan persistentnya di lapangan. Kertas ini disedia bagi memperihalkan status penggunaan kedua-dua jenis agen kawalan biologi disamping mengesyurkan penyelidikan yang perlu dibuat untuk mempertingkatkan kegunaan dan memaksimumkan dampaknya dalam pengurusan rama-rama ini masa akan datang.
    Matched MeSH terms: Weather
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