International Journal of Environmental and Rural Development
Online ISSN : 2433-3700
Print ISSN : 2185-159X
ISSN-L : 2185-159X
最新号
選択された号の論文の26件中1~26を表示しています
  • NARONG TOUCH, TAKAHIKO NAKAMURA
    2020 年 11 巻 2 号 p. 1-6
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Sediment microbial fuel cells (SMFCs) have received considerable attention for remediating sediment and wastewater while providing electricity. This technology offers many benefits for rural regions, particularly for those in developing counties. SMFCs can treat agricultural wastewater, household sewage, and organic waste while providing electricity to households. However, the performance of SMFCs remains low and must be improved. It has reported that mixing steelmaking slag (SS) with littoral sediment improves SMFC performance. The present study examines the use of SS to potentially improve the performance of a SMFC that uses paddy soil as its fuel (PS-SMFC). Moreover, we examine changes in the performance of a SS-SMFC (the PS-SMFC that the anode chamber is filled with SS) that uses lactic acid bacteria (LAB) and BN strain of Bacillus subtilis (BNB) solution-mixed paddy soil as its fuel. In laboratory experiments, paddy soil was poured into the SS layer (the anode chamber) of a SS-SMFC. LAB or BNB were added to the SS-SMFC anode by mixing a bacteria solution with the paddy soil. The SMFC performance was evaluated by measuring the polarization (current–voltage relation) and power density. The power density of the SS-SMFC was observed to be 152 mW.m−2, which is approximately twice than that observed without using SS (80 mW.m−2, as reported in previous studies). This shows that the performance of a paddy soil-used SMFC increases after mixing SS with the paddy soil. Furthermore, the SS-SMFC power density increased from 66 to 191 mW.m−2 after adding BNB and to 247 mW.m−2 after adding LAB. Thus, adding LAB or BNB to paddy soil is shown to improve SMFC performance. In comparison with BNB, LAB has greater potential for increasing SMFC performance.

  • JARUPONG PRASOPSUK, ARUNEE PROMKHAMBUT, SUWIT LAOHASIRIWONG, CHULEEMAS ...
    2020 年 11 巻 2 号 p. 7-11
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    This study reports the pesticide application and environmental impact in Chinese kale cultivation under Good Agricultural Practice (GAP) and conventional practice in North- East, Thailand. The Environmental Impact Quotient (EIQ) model was applied in this study. The data were collected by using semi-structured interviews and observation. GAP farmers (farmers in GAP’s system) and conventional cultivation farmers (non-GAP farmers) were purposive selected, 10 per each group with a total of 20 farmers. Data from farmer interviews on pesticides application, type of substances, application rates, frequency, and plot size were used in the EIQ Field Use equation to assess environmental risks between the two practices. The criteria are EIQ Field Use; <25 = very low risk <50 = low risk 50-99 = moderate risk 100-199 = high risk and> 200 = very high risk. The results showed that 15 active ingredients in pesticide were found in GAP farms and 19 active ingredients in pesticide use were found in non-GAP farms. The GAP Chinese kale has a lower level of impact on environmental risks than the conventional one (Average EIQ Field Use: GAP = 87.4, non-GAP = 136.87). This data indicates that the GAP system could reduce the risk of pesticides in the environment of commercial vegetable-growing village.

  • OGNEN ONCHEVSKI, MACHITO MIHARA
    2020 年 11 巻 2 号 p. 12-19
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Ovche Pole is a region in Macedonia where the main economic activity of people is agriculture. Moderate-continental-sub-Mediterranean climatic conditions are prevalent in the area. However, based on the data for average annual precipitations (P) and potential evapotranspiration (PET), the region has aridity index of 0.64, thus it is classified as dry sub- humid and vulnerable to desertification. The region is dominated by agriculture land which takes 62% of total area, followed by forests and pastures that takes 22.55% and 14% respectively. Vertisols are the dominant soil type, taking 51.24% of total area in the region. Climatic conditions, together with the unsustainable agricultural practices highly influence the process of land degradation, especially soil degradation in the region. The key for success of any land restoration activity is the involvement of local communities. Understanding the farmers’ perceptions on this issue is crucial for development and implementation of sustainable resource management strategies. Therefore, the objectives of this study are to: (i) assess farmers’ perceptions on different types of soil degradation and (ii) examine farmers’ perception and motivation for adopting new SWC practices. A semi-structured questionnaire was developed and distributed to farmers to gather primary data. Out of total population of 375 registered farmers, following convenience sampling method, 102 farmers took a part in the questionnaire survey. Secondary data on climate/weather, land use, soils, demography was obtained from published or unpublished sources. The results of the study show that farmers could observe different soil degradation process on their land. Most of the farmers perceived decline in soil moisture retention as most intense and most significant problem. For majority of interviewed farmers, the main criteria to adopt SWC are the increased financial benefits and gains from the new measure and financial incentives provided by government institutions.

  • MALEE THUNGRABEAB, PATCHARIN KRUTMUANG
    2020 年 11 巻 2 号 p. 20-24
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    The objective of this study was to evaluate the compatibility of entomopathogenic fungi with repellants to control bean fly, Ophiomyia phaseoli Tryon (Agromyzidae: Diptera). Nine isolates of entomopathogenic fungi belonging to 3 genera and 5 species were screened for pathogenicity against bean fly. The results found that Beauveria bassiana isolate Bff and Metarhizium anisopliae isolate Mff caused 100% mortality to both its larval and adult stages. The repellency of 7 essential oil was also evaluated against adult bean fly in the laboratory. The results showed significant differences in repellency among essential oil and concentrations. Essential oil extract from pomelo peeling was the strongest repellant followed by eucalyptus and sweet basil. However, essential oil extract from camphor was the weakest repellant. On the other hand, these seven essential oils (pomelo, zingiber, citronella grass, eucalyptus, camphor, kaffir lime and sweet basil) at a concentration of 0.1% had no effect on the viability of conidia, but at higher concentrations it was found that citronella grass and zingiber reduced viability of B. bassiana. The results on the effect of essential oils on colony growth showed the same tendency as the one on the viability of conidia.

  • SAVOEURN LANG, SOPHAONARITH RO, SIRANET ROEURN, LYHOUR HIN
    2020 年 11 巻 2 号 p. 25-30
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Rice (Oryza sativa. L) is widely cultivated in Cambodia, but it consumes considerably more water than any other crops. In the context of water scarcity due to global climate change, rice cultivation in Cambodia has been worsened by the effect of drought. Development of a cultivation technique to minimize yield loss under drought stress or/and limited water resource in rice production is of great strategic value. Therefore, the present study aims to investigate growth and yield performances of three rice genotypes, namely CAR 14, CAR 15 and CAR 16 under different water regimes including drought (at flowering stage), alternative wet and dry (AWD), and flooded conditions. The experiment was conducted from January to October 2019, at the Tonle Bati Agricultural Development Center, located in Bati District, Takeo Province, Cambodia. The soil is clay loam and is classified as Toul Samrong (Soil Classification for Rice Production in Cambodia). Two-way ANOVA was utilized to determine interaction between the genotypes and the water regimes. As a result, the genotype-water regime interaction was detected for grain yield. Water regimes affected grain filling percentage and yield, whereas rice genotypes affected plant height, 50% flowering days, 100% flowering days, number of unfertile grains, grain yield, and 1000 grain weight. Nevertheless, plant density, panicle length, and straw biomass were not affected by either of the factors. In any water regimes, CAR16 grew the tallest at 94.4 cm and blossomed 2 to 4 days later than any other cultivars. In contrast, CAR 15 had the highest yield, observed in permanent flooding and in AWD. Although 27% of irrigation water was saved in AWD, permanent flooding produced more yield. In short, drought conditions affected total yield. Despite that, Car 15 was observed to be more suitable for any water regimes.

  • EMMANUEL OKIRIA, HIROMU OKAZAWA, YURI YAMAZAKI, YUKIMITSU KOBAYASHI, S ...
    2020 年 11 巻 2 号 p. 31-37
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Long-term stream discharge data is indispensable in irrigation and drainage design. However, in Uganda, this data is poor and insufficient, limiting irrigation system design. Conversely, the rainfall monitoring network is denser than the river flow monitoring network. Therefore, we attempt to build a model that calculates river discharge from input of rainfall. In this study, the lumped parameter Tank Model was applied. The model was applied to the Namatala River catchment (155 km2) in Eastern Uganda. The study sought to ascertain the applicability of a lumped parameter model to a mid-sized catchment. Specifically, the objectives were: 1) To calibrate the numerical values of Tank Model parameters, 2) To verify the Tank Model parameters. This Tank Model required daily rainfall, evapotranspiration and river discharge data during calibration. Data for years 2015 and 2016 was used for calibration and validation respectively. During calibration, Monte Carlo simulation was used to find the numerical values of 16 Tank Model parameters. The best performing calibration parameter set had Nash-Sutcliffe (NS) efficiencies of 0.608 and 0.257 in calibration and validation respectively. However, among the 2015 calibration parameter sets, the one with a calibration NS of 0.502 performed best in validation (NS = 0.526). Equifinality was observed during parameter calibration. By using Tank Model, simulated discharge was divided into its surface runoff, interflow and base flow components. Tank Model was adaptable to Namatala River catchment.

  • NAHO NOHARA, TADAO YAMAMOTO, TAKASHI KUME, KATSUYUKI SHIMIZU, CHULEEMA ...
    2020 年 11 巻 2 号 p. 38-45
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Salt-affected soil is a serious problem in Thailand, and most of this soil is found in the northeastern part of Thailand. The total area of saline land in Northeast Thailand is 2.85 million ha, which accounts for about 17% of this area (Land Development Department,2011). The objective of this study is to evaluate the effect of desalinization by digging drainage channels in salt-affected fields during rainfall. The study was conducted on a high salinity field in Khon Kaen, Thailand. In April 2019, the main drainage channel of a depth of 1 m, was excavated across the center of the field in the south-to-north direction. Additionally, side ditches were installed along the circumference of the west part of the field. We constructed drainage channels to promote field drainage and effectively induce salt leaching with rainfall. Field observations were conducted eight times, especially in the rainy season, from August 2018 to September 2019. Soil apparent electricity conductivity (ECa) was measured using an electromagnetic induction meter in three distinct depth ranges, i.e., 0.375 m, 0.75 m, and 1.5 m, from the soil surface. Soil salinity was represented as contour maps based on spatially interpolated data and spatial distribution and temporal changes were analyzed. The soil ECa in the field gradually increased from upstream to downstream. Moreover, it was higher near the surface and lower deep underground. By comparing the soil salinity observed in the later part of the rainy season in both the years, ECa was observed to have decreased by 20% from August 2018 to September 2019. The ECa values at depths of 0.375 m and 0.75 m in the west part of the field, which had side ditches, were significantly lower than those in the east part of the field two months after the drainage channels were constructed. However, a contrary result was obtained after a heavy flood. These results indicate that drainage channels contribute to salt leaching with rainfall. Our results suggested that excavating drainage channels could effectively reduce soil salinity during the rainy season under good drainage conditions.

  • RAKSMEY PHOEURK, KIMCHHIN SOK, MALYNE NEANG
    2020 年 11 巻 2 号 p. 46-52
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Rice is significant in Cambodian food security. The main cultivated area is in central plain and floodplain of Tonle Sap Lake (TSL). TSL provides importantly both provisioning and regulating services to rice cultivations in its floodplain such natural flood for irrigation, soil fertility from sediment and aquatics animals specifically fish and snakes which regulated and improve the rice cropping system naturally. However, changes of the Mekong River (flood pulse) and climate change impact on changes of rice cropping systems (RCS) observed recently. The objective of the study aims at carrying out farmer’s perception on ecosystem services (ES) in comparison with two sites of Low-water-land (LWL) and middle-water-land (MWL) in Sangkae district, Battambang province. An agrarian system analysis and diagnosis method applied for whole implementation with 120 rice farmers for this survey. Flood-pulse of TSL have change to lower and lower which led some part of floodplain became infertility, so farmers have changed their traditional rice cropping systems (floating rice and long-term rice) to high-yield rice; shifted from traditional techniques to modern systems by adopting new innovations, inputs and technology, chemical fertiliser and modern machineries. Nevertheless, from our study, the new rice cropping systems seem to be less sustainable, inadequate use of new technologies or inputs in the study areas. Rice cropping systems in MWL is more profitable than LML site. Farmers in both sites are aware of the ecosystem services provided by TSL, but not all of them perceived the same importance among the RCS because of agroecosystem differentiation. The poor farmers, who lived in and closer to the TSL basin relied the most on traditional rice; floating and long-term rice, were vulnerable to food insecurity and insufficient household’s income, changes of the ecosystem services in their regions. They reported the ES are more importance to their RCS than other medium and large farmers. Adaptive RCS and irrigation system should promote corresponding to the dynamic changes, ecosystems of Tonle Sap Lake.

  • YUSUKE KURATA, KAZUKI ADACHI, SIRJANA KAFLE, KAZUHIRO NEMOTO, MITSURU ...
    2020 年 11 巻 2 号 p. 53-61
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    The Nepal government introduced Technical Vocational Education to secondary schools nationwide in 2014 as part of its School Sector Reform Plan (running from 2009 through to 2015). The purpose of agricultural education in secondary schools is to develop a workforce to support the nation’s agricultural development and alleviate poverty. This case study analyzes the current status of and issues with agricultural education at a secondary school in epal’s Mustang District. First, the curriculum and syllabi of the Plant Science Stream program were reviewed. Second, the school’s teaching activities were analyzed and compared with the teaching methods in use at a Japanese agricultural high school in the Nagano Prefecture. The head of the school and a teacher of agriculture conducted observations and interviews regarding the Japanese high school’s teaching practices in September 2017. After observing the Japanese high school, focus group discussions were conducted with five other agriculture teachers at the targeted school in Nepal. The discussions found that the content of the lectures did not adequately explain local farming practices. It was determined that the study program should conduct cultivation trials of local products in the school farm. Students could interview local farmers and observe their crop production, agro-processing, livestock rearing, and natural resource managements. Students could practice farming to use the products for their own consumption or sales at school and local markets. These activities can strengthen students’ understanding of agricultural information and techniques. The suggested activities would also allow the teachers to learn what information to include in the lectures and practices to support students’ knowledge of farming practices relevant to the local area.

  • CHAW SU HLAING, NAN NOE NOE OO, AH MAR YI
    2020 年 11 巻 2 号 p. 62-70
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Inle Lake is the second largest natural lake in Myanmar. It has a population of some 150,000 people, many of whom live on floating islands of vegetation. About half of the people who live in Inle Lake work the traditional hand weaving business. It is now facing the environmental degradation of its area due to human activities. Direct discharging of wastewater containing contaminants (especially azo dyes and heavy metals) from dyeing process into its environment impairs the soil and water qualities and causes a series of problems in living beings. In this research, the treatment of wastewater of dyeing process from silk, lotus and cotton hand weaving workshops in Inle lake was performed by sorption technique using local available waste, lotus stalk and coconut shell charcoal as the major sorbent materials. The results obtained from dyed wastewater treatment using activated coconut shell charcoal (5 g), activated lotus stalk (5 g), and a combination effect of activated lotus stalk and activated coconut shell charcoal at a 4:1 ratio for appropriate time taken treatment indicated that the highest color removal efficiency (94%, 95%, 100%) respectively. Therefore, a combination of sorbent materials (4:1) might be the best choice for the dyed wastewater treatment. The resultant data of before and after treatment of wastewater were compared with WEPA standard for public health. Some tested heavy metals and physicochemical properties of treated water were within the WEPA standard. However, long term disposing of wastewater without proper treatment causes a serious problem. Therefore, treatment of wastewater before discharging into its environment is necessary for the conservation and sustainability of Inle Lake.

  • WAI ZIN PHYU, MOE HNIN PHYU, THI TAR OO
    2020 年 11 巻 2 号 p. 71-77
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    This study was conducted to investigate the species diversity of arthropod natural enemy species structure in intensive monsoon rice cultivation areas during 2018. The study site is Kyee Inn village, Pyinmana Township, Myanmar, and over 550 ha. Data collected from (300 m x 300 m) grid pattern and 56 grid points (G) using a D-Vac vacuum suction- machine. This study identified eight orders, 30 families, 57 genera, and 28 arthropod natural enemy species. The highest species richness occurred in Order Hymenoptera, followed by Order Coleoptera and Order Hemiptera. The diversity of natural enemy was varied widely with different grid points. The recorded equitability (evenness) was equally abundant in most grid points, but some have high single-species dominance. The highest number of Cyrtorhinus lividipennis (Order Hemiptera) found in G18, even though G18 displayed a medium diversity index and low equitability. The population of Cyrtorhinus lividipennis was higher than other species in all grid points. It may due to food sources are abundant during the growing season. Fortunately, we observed many natural enemy species, and it should conserve for natural balance to maintain the pest population.

  • MITSURU HAMANO, NAOKI NAKANO, SOCHEAT NAK, KASUMI ITO
    2020 年 11 巻 2 号 p. 78-85
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    For years, farmers in rural Cambodia have practiced small-scale pig farming mainly with family-based production. However, in recent years, there has been an increasing inflow of imported pigs grown with a lower production cost in neighboring countries. In addition, the share of products from domestic large-scale pig farming using commercial production systems has been increasing. This situation has led to price fluctuations in Cambodia’s highly competitive pig and pork meat market, which affect family-based small-scale pig farming in rural areas. This study aimed to identify various management styles of small-scale pig farming and analyze their business status to discuss the profitable management styles under low sale price conditions. To grasp the pig farming styles, key informant interviews were conducted with government officers, middlemen, and pig farmers in the Treang and Tramkak districts of Takeo Province and in urban markets of Phnom Penh. The economic statuses of pig farming were clarified by interviewing the pig farmers and observing their rearing practices in the same areas to compare the profitability of different management styles. As a result, three pig farming styles were identified: fattening, breeding, and both. On the other hand, some farmers fed their pigs mainly with rice liquor residues with compound feeds, while some did not use rice liquor residues at all but mainly compound feeds. The comparative analysis of their economic statuses clarified that combining the fattening and breeding operations and feeding the pigs with both compound feeds and rice liquor residues effectively decreased the production costs and yielded comparatively high profits.

  • NYO MAR HTWE, MYINT AYE, CHAN NYEIN THU
    2020 年 11 巻 2 号 p. 86-91
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    To select improved rice lines according to a selection index, a field experiment was conducted using fifty improved rice genotypes, during the dry season of 2017 at the Department of Plant Breeding, Physiology and Ecology, Yezin Agricultural University, Myanmar. The examination used a Randomized Complete Block Design with three replications. Days to 50% flowering, plant height, number of effective tillers per hill, filled grain percentage, 1000 seed weight, number of spikelets per panicle, harvest index and yield per plant exhibited highly significant differences indicating the existence of genetic variability among the improved rice lines. There was not much variability in panicle length. Seed yield per plant was positively and significantly correlated with days to reach 50% flowering, plant height, the number of effective tillers per hill, filled grain percentage, number of spikelets per panicle and the harvest index at phenotypic and genotypic levels. This shows that indirect selection on these traits would be effective in improving grain yield. At the genotypic level, path coefficient analysis shows that number of spikelets per panicle, the 1000 grain weight, filled grain percentage, number of effective tillers per hill, plant height and harvest index has a positive influence on seed yield. The selection index based on the combination of number of effective tiller per hill, filled grain percentage, number of spikelets per panicle and seed yield per plant (ETPP+FGP+SPP+SYPP) has the highest genetic advance and relative efficiency. This indicated that indirect selection via these traits would be more efficient than direct selection using yield alone. Therefore, the genotypes; YAU- 1215-S-S-S-41-1-1, YAU-1211-9-3-1, YAU-1211-71-1-1, YAU-1211-118-2-1 and YAU-1201-151-1-1 could be selected based on multiple traits selection for further evaluation.

  • LYTOUR LOR, MACHITO MIHARA, BUNTHAN NGO, LYHOUR HIN, DYNA THENG, CHANM ...
    2020 年 11 巻 2 号 p. 92-97
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Biogas systems are being applied at commercial pig farms and at starch processing plants to manage their wastes and produce biogas for generating electricity or heat for on-site use. The installation numbers are increasing in Cambodia. The data on potential biogas production quantity from different feedstocks as well as on biogas quality are required to design the biogas systems. The purposes of this study was to determine biogas production and biogas quality from dairy cow manure produced in pilot digesters, and to analyze the variation in biogas production and quality during the year of 2019 and 2020. Pilot bio- digesters were installed at the Biogas Technology and Information Center, a research unit located in the Royal University of Agriculture, to obtain these data, since it is easier to do the experiments with the pilot digesters than that with commercial ones. The experiments were conducted during the year of 2019. In the experiments, 3 identical floating drum bio-digesters were used. Each bio-digester has 1 m3 of volume and has been supplied mixture of 5-10 kg of fresh manure from dairy cattle with 5-10 liters of water every day. The daily biogas production quantity was recorded using a gas flow meter attached to the outlet of each bio- digester; also the gas quality, such as methane, carbon dioxide, oxygen, and hydrogen sulfide was measured using a portable biogas analyzer. The average rate of biogas production was around 37 liters of biogas per kg of wet manure. Average percentage of methane was around 52%, and average concentration of hydrogen sulfide varied from around 390 ppm to 604 ppm. These two parameters are the main indicators of biogas quality.

  • MAKOTO SHINOZAKI, SAWAHIKO SHIMADA, AYAKO SEKIYAMA, KIYOSHI TAJIMA, HA ...
    2020 年 11 巻 2 号 p. 98-103
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Crop cultivation in Djibouti is mainly done by irrigation agriculture obtaining groundwater from wadi aquifer. The decreasing in the efficiency of solar power generation system due to panel-on-dust is reported to be the issue in terms of energy loss in pumping up water. In this paper, the effect of dust deposition for solar pumping system was evaluated at wadi agriculture farm in Dikhil, Djibouti. The amount of panel-on-dust was measured to be 1.88 and 2.1 g/m2 in cooler season (dry deposition) and in hot season (wet deposition), respectively. Clearance of the panel-on-dust resulted a decline in the output power of photovoltaic panel due to the rise in panel surface temperature in January (cooler season), whilst the output power increased in September (hot season) when the panel surface temperature was relatively higher. The conversion efficiency of the photovoltaic power generation was calculated to be about 5 - 6% lower in September than in January. The whole conversion efficiency of solar pumping system was estimated to be about 2%. Since the ideal conversion efficiency was calculated as 6.76%, the gap from observed value of about 4.5% can be implied by suppressing water leakages from the system in pumping process.

  • KHEANG SONG, SOPHAL VAR, SAVRY POENG, KIMYEE ORNG, CHANTHA SENG, SOPHO ...
    2020 年 11 巻 2 号 p. 104-108
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    In Cambodia, potato is imported. Currently, potato has the fourth largest production in the world cultivated in many countries even in semi-arid and tropical countries. Numerous new and improved varieties were developed to sustain and maintain production systems. Thus, performance evaluation of these varieties in Cambodia condition is important to improve potato production in the country. The experiment was conducted from December 2016 to March 2017 by testing 8 different imported varieties (Tornado, Corodana, Georgina, Madeira, Jelly, Julkinka, Red fantasy and Sorentina) under upland climate of Cambodia. The result showed that all varieties showed similar performance in terms of growth, but different in yield components and yield. Tornado variety was most adapted and productive varieties with an average yield of 23ton ha-1 followed by Madeira (19 ton ha-1) while Red fantasy had the lowest production among the tested varieties under upland environment in Cambodia.

  • HAN SU YIN, SEINT SAN AYE, HTAY HTAY OO, YI YI MON, TIN AYE AYE NAING
    2020 年 11 巻 2 号 p. 109-115
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Rice is the major food crop in Myanmar and bacterial blight is one of the devastating diseases affecting production. In this study, 37 local rice varieties and 41 rice lines were tested at Yezin Agricultural University, Myanmar, to three different isolates of Xanthomonas oryzae pv. oryzae to evaluate the resistance levels of these different rice varieties. The three bacterial isolates used in this experiment were collected from Zeyathiri, Zabuthiri and Pyinmana townships in Nay Pyi Taw Union Territory. At maximum tillering stage, the uppermost fully expanded leaves were inoculated by the clipping method. Three weeks after the inoculation, the percent leaf area of the inoculated leaves was visually estimated and the disease reaction of the rice varieties determined. The thirty-seven local rice varieties were classified into seven groups, with this grouping based on the reaction patterns to the three isolates. Group VII, which contained two varieties, Nga Sar Kay and Sinthukha, was moderately resistant to Pyinmana isolate and moderately susceptible to the Zeyathiri and Zabuthiri isolates. The rice varieties included in Group I to Group VI showed susceptible reactions to testing with all three isolates. Among YAU rice lines tested, YAU-1211-71-1-1 exhibited moderate resistance to the Pyinmana isolate only. Apart from the line mentioned above, all the other YAU rice lines, did not exhibit resistance reactions to the test isolates. Nga Sar Kay, a local rice variety, has the potential to be used in the future rice breeding programs and YAU-1211-71-1-1 is the promising one to be used in areas where rice bacterial blight disease is prevalent.

  • SHINOBU YAMADA, MACHITO MIHARA, KUMIKO KAWABE
    2020 年 11 巻 2 号 p. 116-122
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Recently, vegetable has also been cultivated by many farmers in Cambodia due to the increase of its demand in the local market. The main objective of this study was to clarify the awareness levels of the local farmers with an emphasis on agriculture production information for the sustainable development of vegetable production. Based on the multiple correspondence analysis results, the information required by local farmers was shown to be different depending on farm management scale. It can be concluded that it is important to provide information and technology that is adapted to the development stage of agricultural management of each local farmer. Moreover, a categorical principal component analysis is used to categorize and clarify the effectiveness of kind of agricultural production information was needed to develop vegetable production.

  • KHEANG SONG, SOPHAL VAR, SOVANBOREY OY, SEANGLY KHEANG, SOPHOANRITH RO ...
    2020 年 11 巻 2 号 p. 123-127
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Potato (Solanum tuberosum L.), a tuberous plant well known as a highly nutritional diet and an economic crop s, is the world’s fourth largest production after rice, wheat and corn. Recent experiments have shown some potential places and varieties for cultivation in Cambodia. Thus, the experiment aimed to understand the response of the potential potato varieties to different planting dates in Sen Monorom town, Mondulkiri province (a mountainous area), Cambodia. The trail was laid out in randomized complete block design with 4 replications and 3 different planting dates namely October, November and December of 2018. The Coronada, certified seed from the Europlant International company in Germany, was the ideal variety used in the experiment and lasted 115 days from planting to harvest. Only the number of tuber per plant, tuber weight, weight per plant, and marketable yield were recorded. Suggested that planting date significantly affected to all measured parameters. Plot planting in December produced the highest number of tubers with an average of 9.3 tubers per plant while a similarity was noticed for October and November planting. However, the November planting surprisingly produced the highest weight per plant, heavier tuber and the highest marketable yield with 19.15 ton ha-1. The two other planting dates obtained an average yield of 14.49 and 12.39 ton ha-1 for October and December consequently. This is understandable that November planting and harvest at end February, which is the long cold and windy season with less rainfall, was the most comprehend planting season in Mondulkiri province, Cambodia.

  • DALIN SUN, TOMOHIRO UCHIYAMA, NINA N. SHIMOGUCHI
    2020 年 11 巻 2 号 p. 128-133
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Agricultural machinery has become significantly important to carry out farm work and to address labor scarcity in Cambodia. However, rural areas face many challenges such as lack of farmers’ improper machinery utilization and lack of skilled operators in order to implement agricultural mechanization. The effective use of tractor or combine harvester (CH) requires not only management knowledge and experience, but also proper the economic evaluation. This study aims to determine the potential of rice tractor and combine harvester custom service to create an economic advantage for the agricultural machinery owners. A survey of 28 tractor owners (group T), 21 CH owners (group CH), and 23 tractors and CH owners (group B) in Banan District, Battambang Province was conducted in March 2019. The result indicated that the annual custom service area by group T, CH, and B were 133.4 ha, 213.1 ha, 398.9 ha (tractor 180.8 ha, and CH 216.1 ha), respectively. The average operating cost was estimated at 30.0 USD/ha for group T, 58.9 USD/ha for group CH, and 26.2 USD/ha (tractor) and 56.3 USD/ha (CH) from group B. Among the costs incurred, depreciation cost was the highest cost, followed by diesel and labor costs. In some cases, owners tend to offer higher pay to skilled operators to work for them especially during the peak seasons. The break-even point per year were estimated at 116.4 ha for group T, 117.5 ha for group CH, and 113.0 ha (tractor) and 109.6 ha (CH) for group B. In general, custom service by group seemed to vary on the field and infrastructure conditions, operators’ skill, frequently machine breakage, and owners’ desire to gain profit. Therefore, this study suggests that the owners should prolong the economic life of tractors or CHs by conducting proper and regular maintenance that will eventually lead to decrease break-even area.

  • NINA N. SHIMOGUCHI, JENNICA AMIELLE M. MORA, ELIZA C. AQUINO
    2020 年 11 巻 2 号 p. 134-139
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Japanese agriculture has been facing various challenges such as increasing population of elderly farmers and lack of successors. Moreover, several environmental and market issues have tested the capability of Japanese farmers to cope. Through a case study approach, this study aims to clarify the coping strategies of farmers in K City, Chiba Prefecture to recent challenges and determine the issues to support and sustain their local agriculture. A series of visits were conducted in 2018 and 2019, and in-depth key-informant interview was conducted in June 2019. In-depth key-informant interview revealed that farmers from K City organized a Farmers’ Market at their own initiatives to sustain and support the local agriculture for the next 10 to 20 years. Since the establishment of the Farmers’ Market in 2003, the farmers faced pesticide residue reports on turnip and various vegetables in 2008 and 2010, respectively; radiation residue report as an effect of the 2011 Great Tohoku Earthquake and Nuclear Plant Meltdown have brought negative impacts to the farmers as harmful rumors on the safeness of the agricultural products from K City spread to name a few. Farmers have initiated innovative actions and adapted strategies to overcome these challenges. SWOT analysis revealed that the farmers, at their own expense, regularly tested the produce for pesticide and radiation residue to assure its quality and safeness. However, if not continued, misconception among consumers will prevail then lead to distrust. They even provided other services such as restaurant, café, farm tour and seminars. On the other hand, the farmers recently tend to supply to other markets aside from the Farmers’ Market, conveying a significant supply issue to be addressed. In general, these strategies and initiatives which reflect the farmers’ passion and motivation to achieve sustainability seemed to be the factors that made them resilient to the changing environment.

  • NWE NI WIN, MOE HNIN PHYU, THI TAR OO, KYAW KYAW WIN
    2020 年 11 巻 2 号 p. 140-145
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    The abundance of Hemiptera and Diptera fauna studied on monsoon rice at Kyee Inn village, Pyinmana Township, Myanmar, 2018. Insect species were collected from 56 grid points (G) using a D-Vac vacuum suction-machine. Using simple correspondence analysis, the peak number of Sogatella furcifera occurred in G33, the second-highest number of Nephotettix virescens in G35, followed by Nilaparvata lugens in G30, they belong to the order Hemiptera. In order Diptera, Aedes stimulans in G38 is the highest mean number, followed by Chironomus sp. and Uranotaenia sapphirina from G32 and Hydrellia philippina from G33 was observed. Correspondence analysis showed species population of order Hemiptera is more abundant than the order Diptera. The population of major insect pest species such as Nilaparvata lugens and Sogatella furcifera occurs at higher density during the study period. It is due to the usage of broad-spectrum chemical insecticides in the early crop growth stage. In order Diptera, Hydrellia philippina is a pest on rice, but Aedes stimulans and Uranotaenia sapphirina are not the rice pests, even though Aedes stimulans is a vector of dengue disease. Meanwhile, Uranotaenia sapphirina feeds on the invertebrate host. The results indicated that Hemipteran fauna is more abundant than Dipteran. We need to give Hemiptera’s serious pests more attention to provide the proper control measure for them.

  • TAKANORI KANEKO, TOMONORI FUJIKAWA, MACHITO MIHARA
    2020 年 11 巻 2 号 p. 146-153
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Earthworms have significant impacts on the physical and chemical properties of soils. It is known that they are remarkably improving soil fertility as well as promoting plant growth because earthworms make castings, which are rich in nitrogen, phosphorus and other nutrients. Additionally, earthworm’s movements effects soil properties by their movements in the soil, notably soil aggregates, nitrogen and phosphorus concentration. Earthworms from Megascolecidae family are a major earthworms found in Japan, but there is lack of knowledge on its effect on soil properties compared to other earthworms. Subsequently, this study discusses the changes in soil aggregates, nitrogen and phosphorus concentration changes with depth due to Megascolicidae movements in the soil. An experiment was conducted using cylindrical columns of 12 cm height divided into 3 layers at 4 cm interval. Additionally, two groups were made, with litter and without litter, which were divided into subgroups with variations in earthworm numbers. The results of aggregates showed the tendency of aggregate formation in both the groups, with high formation rate in litter added group. The results of NO3 and P2O5 content significantly differed among the 3 layers in the treatments. The trend of higher NO3-N and P2O5 concentration was observed in middle layer and lower layer respectively. According to the results obtained, Megascolicidae movements effect the distribution of nutrients in subsurface soils.

  • TONG SOCHEATH, BORARIN BUNTONG, ANTONIO ACEDO JR.
    2020 年 11 巻 2 号 p. 154-162
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Tomato (cv. Mongal) value chain practices of a farmers’ cooperative as pilot model in Siem Reap, Cambodia, were assessed and improved through the introduction of postharvest technologies and best practices. The existing value chain (EVC) practices included harvesting tomatoes at the breaker stage, use of harvesting container with smooth surface (plastic pail), use of plastic crate in hauling harvested tomatoes to the farmers’ house where packaging in ordinary plastic bags at 10 kg fruit per bag was done. No sorting and special storage were practiced except for overnight storage at ambient when harvesting was done in the afternoon. The packed fruit were then transported to the city market about 12 km from the farm or 30-45 minutes ride using a motorcycle-driven carrier (locally named ‘TukTuk’). Marketing tomatoes usually took half day. Using the cooperative’s simple packhouse which linked farm production and marketing, improved value chain (IVC) practices were introduced, including sorting to ensure more uniform quality and damage-free fruit, sanitizing with 0.01% calcinated calcium (non-chlorine sanitizer) by dipping fruit in the solution for 3 minutes, modified atmosphere packaging (MAP) using perforated 50 µm thick low-density polyethylene bag at 10 kg fruit per bag, and transporting and direct retailing in ice box using a dedicated motorcycle-driven carrier. In another set of trials, three-day storage simulating extended period of distribution and marketing was included using ambient condition in the EVC while in the IVC, three storage options were introduced: ice box (3 kg ice per box with about 25 kg fruit replenished every day); low-cost cold storage using the Coolbot chamber; or evaporative cooler (EC). Results revealed that without storage (direct marketing after harvest) total postharvest loss was about 14% in the EVC; this was remarkably reduced to 4% in the IVC. IVC fruit were also firmer, had higher soluble solids and much reduced microbial load than EVC fruit. No pesticide residue was detected in both EVC and IVC fruit. With the three-day storage, the three storage options in the IVC did not differ much in reducing postharvest loss to about 3-6% from 22% in the EVC. IVC fruit also ripened slowly resulting in higher firmness than EVC fruit. Other quality attributes were not affected. Vitamin C content was slightly higher in IVC fruit than in EVC fruit. From the results, there is potential for integrating postharvest management options in value chains to reduce postharvest loss and enhance quality of tomatoes.

  • YU MON, YOSHINORI YAMAMOTO, MIE MIE AUNG
    2020 年 11 巻 2 号 p. 163-169
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Among the five rice ecosystems in Myanmar, submerged and deep-water areas occupy 13.5% of the total cultivated area. If flooding occurs, most rice varieties elongate and lay flat after the water recedes. In such a situation, the lodged stems are cut and transplanted without roots. This cut-stem transplant (CST) method is practiced locally in Ywa Houng village, Thanatpin Township in the Bago Region, using deep-water rice (DWR) varieties such as Pawsan and Yoesein in deep-water areas. However, a high yielding variety, Byaw Htun, is cultivated in the shallow-water areas by using direct seeding (DS) or the normal transplanting (NT) method. Unusual levels of flooding in 2018 resulted in almost all of the fields being subject to deeper water conditions than normal in Ywa Houng village. The highest flood level occurred on 19th July, with a 45cm depth recorded, in what is normally a shallow area (normally less than 25cm depth) and the flood peaked for about 25days. Hence, transplanting of Byaw Htun was delayed until the 10% heading stage in the nursery. Thus, farmers tested the CST method in place of NT method in Byaw Htun. This study examined to clarify the growth and yield of CST method for the Byaw Htun variety. Byaw Htun CST plants exhibit plant growth and yields comparable to those of DS plants. In addition, the yield of Byaw Htun CST was similar to, or higher than those of Pawsan and Yoesein CST. However, the harvesting of Byaw Htun CST took place far later than that of DS areas. Consequently, it was found that CST can be applied for Byaw Htun varieties when the plants were damaged by flooding, but due to delays in harvesting, the application of this method should be considered in relation to any subsequent crops to be cultivated.

  • ZUN PHOO WAI, NYO MAR HTWE, SU LATT PHYU
    2020 年 11 巻 2 号 p. 170-175
    発行日: 2020年
    公開日: 2022/05/14
    ジャーナル フリー

    Genotypic selection for higher total dry weight has become a key method of research and experimentation to increase grain yield. Therefore, this experiment was carried out to determine the relationship of leaf area index (LAI) and yield and its components for ten genotypes of improved rice, for normal and late growing seasons. The experiments were conducted in the experimental fields of the Department of Plant Breeding, Physiology and Ecology, Yezin Agricultural University. The study was undertaken from December 2016 to May 2017 for testing normal growing season plants and March 2018 to July 2018 for late growing season plants. A randomized complete block design with three replications was used. For the relationship among all the traits tested, positive associations were found (R2 > 0.5) for LAI at harvest and yield (R2 = 0.574), for panicle weight at harvest and yield (R2 = 0.558), and for harvest index (HI) and yield (R2 = 0.61). The study showed that yields increase along with an increase in LAI and panicle weight, for the improved rice genotypes that were tested. There was a positive and significant correlation found between LAI at heading stage and percent of filled grains in normal season, and LAI at heading and number of panicles per meter square in late season. In late season, the correlation between LAI at harvesting stage and yield was significant; HI was also significantly correlated with percent of filled grains and yield. As LAI and harvest index contribute to yield and yield component characters, breeders may successfully attempt to boost potential yields by increasing growth traits such as plant foliar surface and harvest index.

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