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A Practical and Efficient Method for the Micropropagation of Japanese Cherry (Prunus sp.)

Nguyen Thi Thuy Linh, Pham Thi Ngoc, Ninh Thi Thao, Nguyen Thi Phuong Thao

Received: Feb 15, 2019 / Published: Feb 16, 2019
This study was conducted to establish the procedure for in vitro propagation of Japanese cherry (Prunus sp.) to produce large quantity of plantlets and initial planting materials for climate adaptation research of this plant in Hanoi. Single nodal stems were used as the primary explants and initially produced shoots on MS medium supplemented with 1 mg L-1 BA. The highest shoot multiplication rate (9.57 times) was obtained on MS medium containing 1 mg L-1 BA and 0.25 mg L-1 a-NAA after 8 weeks of culture. 100% of the shoots produced roots with a mean of 10.10 roots per plant within 4 weeks on ½ MSM medium with 4 mg L-1 IBA. The survival rate of in vitro derived plantlets after a 6 to 7-week-period of rooting during acclimatization using a soil: coco peat: smoked rice husks (2:2:1, v/v/v) substrate was 100% and acclimatized plantlets showed good growth and development. This is the first report on a practical and efficient in vitro multiplication protocol for Japanese cherry in Vietnam, starting from shoot initiation to establishment of plants under greenhouse conditions.
Production Efficiency Analysis of Indigenous Pig Production in Northwest Vietnam

Tran Ba Tuan, Yin Tong, Tran Huu Cuong, Nguyen Cong Tiep, König Sven

Received: Jun 18, 2020 / Published: Dec 31, 2020
This research was conducted to investigate the production efficiency of Ban pig production in northwest Vietnam between October 2016 and January 2017. Primary data obtained from 171 producers were analyzed by applying cost-benefit analysis and stochastic frontier production function. The benefit-cost ratio per litter was 1.24, indicating that the enterprise was profitable. Compared to other farms, the farms focused on farrow-to-finisher attained the highest net return (EUR 213.71/litter), while inputs were used most effectively by the mixed farms. The results from the Cobb-Douglas production function revealed that labour, feeding costs, stocking density, and pigpen structure had positive effects on the production output. Additionally, farms with the phase of farrow-to-nursery obtained less total revenue, while farms focused on the farrow-to-finisher phase achieved higher production outputs than the mixed farms. The level of technical efficiency for each farm ranged between 0.62 and 0.98, with a mean of 0.88. The number of live-born piglets and depreciation cost had positive effects, whereas the nursery interval had a negative impact on the technical efficiency. Ban pig producers could increase technical efficiency by efficiently utilizing available resources and improving managerial skills.
A Review of Digital Economy and Digital Economics

Do Kim Chung, Luu Van Duy

Received: May 09, 2022 / Published: Mar 29, 2023
Under the burgeoning of the digital era and global crisis of climate change and health, most countries around the world are moving to digitalize their economies. Digitalization is fundamentally changing all social and economic sectors. However, the existing studies have paid much attention on digital economy rather than digital economics. Drawing from recent literature, this paper critically reviews the understanding of digital economy by examining its meaning, main characteristics, scopes, measurement methods and identifies how digital economy differs to traditional economy. The paper, then, presents a concept and roles of digital economics and the needed suggestions for training digital economics. With this regard, the paper concludes that the education policies should be renovated in order to meet the demands on digital economy. The courses of economics should be integrated with digital economics and sharing economics.
Effects of Culture Conditions on the Antibacterial Activity of Streptomyces Spp. against Erwinia Spp. Causing Soft Rot Disease on Asparagus Officinalis

Nguyen Thanh Trung, Nguyen Thi Van Anh, Tran Thi Dao, Nguyen Thanh Huyen, Pham Le Anh Minh, Pham Hong Hien, Nguyen Xuan Canh

Received: Aug 31, 2020 / Published: Aug 10, 2021
Erwinia is a genus of Enterobacteriacea containing mostly pathogens, which cause soft rot disease in many ornamental plants and crops, including Asparagus officinalis. Chemical treatments to control Erwinia have lost their attractiveness because of the development of resistant strains and the negative impacts on the environment and human health. Therefore, the study of biological controls of soft rot disease has gained great importance. There are several types of microorganisms that show activity against Erwinia spp. such as Pseudomonas fluorescence, Bacillus subtilis, and Streptomyces spp. Among them, Streptomyces spp. are found to be the most effective control agents. In this study, 64 isolates of Streptomyces were screened for their antibacterial activity against Erwinia spp. The results indicated that 18 isolates showed an antagonistic reaction against Erwinia spp. Among them, isolate D5.1 showed the highest inhibition activity. In addition, the morphological and antibacterial activities of isolate D5.1 grown in different conditions were also characterized.
Measures Used for Water Quality Management in Intensive Pangasius Catfish Production in Vietnam’s Mekong Delta: Experiences from Household Practices and Gender Roles

Nguyen Thi Hai Ninh, Ho Ngoc Cuong

Received: Apr 14, 2022 / Published: Dec 30, 2022
Intensive aquaculture on a household-scale in Vietnam’s Mekong Delta region often decreases the quality of the water. The consequences are a negative effect on the yield of Pangasius catfish, which in turn reduces the income generation potential. Water quality management has become an important consideration, not only for sustaining livelihoods from household-scale aquaculture but also for mitigating the impacts on the surrounding water bodies. The purposes of this paper are to identify strategies for improving water quality management in households practicing aquaculture and to understand the role gender plays in water management in the Mekong Delta. The effectiveness of existing household approaches to water quality management was found through analyzing data gathered through interviews. The primary data consisted of interviews with 32 operators of different household-scale aquaculture systems. It was found that in 46% of these households, water quality had declined over the last three years. Several causes were identified including the accumulation of chemicals and antibiotic residues, excessive stocking rates, and a lack of a water treatment system. Several strategies to better manage water quality in these ponds were identified including changing the clean water more frequently, removing sediment after each harvest, planting trees around the ponds, and applying lime to the base of the pond, or using potassium permanganate for disinfection before use. Although many water quality management approaches were in use by households, more than 90% of these activities were implemented by men.
Coping Strategies of Households in Lao Cai Province in Dealing with Risks in Tea Cultivation

Nguyen Thi Thu Quynh

Received: Nov 07, 2022 / Published: Sep 29, 2023
Tea farming households in Lung Vai commune, Muong Khuong district have been facing different types of risks. This study aimed to analyze their current risk-coping strategies, then to propose some solutions for the future. A total of 90 farmers in 3 villages with different production scales had been interviewed using semi-constructed questionare of how they identified and measured risks based on their observations and experience. The statistical descriptions and comparisons results pointed out that most of them were very proactive and flexibly applied different strategies and measures to prevent and minimize losses. However, the differences in the strategies chosen and the level of application among the households depended largely on the household’s resource capacity as well as the awareness of the household head. To promote the sustainable development of tea production in this area, the government and relevant actors in the local tea value chain should work together in order to develop solutions to intervene and support households to improve their capacity to apply risk-coping strategies more effectively in the future.
Sustainability Assessment of the Rural Clean Water Supply System in Hai Phong City

Nguyen Thi Thu Quynh, Nguyen Quoc Hung

Received: Feb 22, 2021 / Published: Oct 29, 2021
Since the end of 2019, 92.1% of rural households in Hai Phong city had been able to access and use clean drinking water, which meets national standards as a result of developing a clean water supply system consisting of 205 plants with various management models. The authors applied the desk-study method to collect and review literature research, select a group of six criteria, and then applied the criteria to assess the system's sustainability based on Likert's 3-point scale. The results show that criteria scores ranged from 1.9 points to 2.5 points, while the total score of the whole system is 12.9 points - reaching an average sustainability level. The authors propose that in order to improve the sustainability of the clean water supply system in the rural areas of Hai Phong city in the future, management agencies and investors need to apply a solution of propagating rural people to increase their usage volume of clean water, which will help to increase the actual operating capacities of the plants, thereby increasing the revenue and profits of plant investors.
Water-Saving Irrigation and Nitrogen Fertilizer Use Efficiency for Irrigated Rice in the Red River Delta, Vietnam

Ngo Thanh Son, Nguyen Thu Ha

Received: Feb 02, 2021 / Published: Oct 28, 2021
The objective of this research was to quantify the effects of water-saving regimes and fertilizer application improvement on water productivity, N-use efficiency, and rice yield. The results showed that the tested water treatments did not have significant effects on the growth and development, yield components, and final grain yield, but water productivity was significantly increased from 1.28 kg grain m-3 (W0) water to 1.74 kg grain m-3 water (W1) and 1.94 kg grain m-3 water (W2). In addition, the percentage of total irrigation water saved from W1 and W2 were 25.24-44.52% compared to continuous flooding. Fertilizer deep placement (FDP) combined with organic compost significantly increased the grain yield of the tested hybrid rice variety. Average grain yield increased quickly from 2847 kg ha-1 with 0 kg N ha-1 to 5263 kg ha-1 with 120 kg N ha-1 under the fertilizer deep placement method. The highest total nitrogen uptake, agronomic nitrogen efficiency (ANE), and nitrogen uptake efficiency (NUE) were obtained from alternate wetting and drying at a -20cm water depth and the fertilizer deep placement method (W1N2). In addition, it also gave the highest income in comparison with the other treatments. Therefore, alternate wetting and drying at a -20cm water depth and fertilizer deep placement method should be encouraged for implementation in other regions of Vietnam.
Assessing Climate Change Impacts and Prioritizing Adaptation Measures Using Climate-Smart Agriculture Rapid Appraisal (CSA-RA): A Case Study in Thuong Bang La Commune, Van Chan District, Yen Bai Province

Vu Thanh Bien, Cunningham Natalie, Nguyen Duc Trung, McKeown Peter, Spillane Charles, Bui Le Vinh

Received: Jan 12, 2021 / Published: Oct 29, 2021
Overwhelming scientific evidence shows agriculture is heavily impacted by negative climate change effects. While agriculture is affected, the sector is also the second-largest contributor to climate change, creating challenges in adaptation and mitigation strategies. Climate-smart agriculture (CSA) is a holistic approach to managing landscapes, utilized to guide farmers in the context of a changing climate. CSA is an attractive option for Vietnam, an agricultural country extremely vulnerable to the impacts of climate change. Farmers and communities in Vietnam are facing significant risks. Changes in farming conditions, climate, and productivity threaten agriculture and livelihoods. The aim of the current study was to assess the effects of climate change on the people and agricultural systems in Thuong Bang La (TBL) commune, Vietnam, utilizing climate-smart agriculture rapid appraisal (CSA-RA) tools. The results indicated that agricultural production has been negatively impacted, with erratic and varied weather patterns causing outbreaks of disease, and reductions in the yield and productivity of livestock and cropping systems. Disasters including flooding, storms, and droughts are a prominent threat, leaving farmers unsure of how to cope. Through a showcase of CSA technologies, farmers were able to highlight their preferences for practices including mulching, drip irrigation and conservation agriculture in orange groves, bio-fertilizers and integrated pest management (IPM) in rice production, and using biological bedding in chicken raising. The study showed immediate openings to initiate context-specific CSA interventions and building the resilience of the agricultural systems in the development of one of the first climate-smart communes in Vietnam.
Students’ Perceptions of Climate Change: A Case Study at Vietnam National University of Agriculture

Nguyen Thi Bich Yen, Dinh Thi Hai Van, Nguyen Thi Thu Thuy, Duong Van Hung

Received: Sep 30, 2020 / Published: Oct 28, 2021
This study aimed to determine the perceptions of climate change of undergraduate students at Vietnam National University of Agriculture (VNUA). The study employed quantitative and descriptive methods using a five-point Likert scale instrument. The respondents were composed of 276 undergraduate students from three faculties, viz. the Faculty of Environmental Sciences (FES), the Faculty of Agronomy (FA), and the Faculty of Economics and Rural Development (FERD). The results showed that students were generally well aware of the causes of climate change, the effects of climate change, and actions to mitigate climate change (average value > 3.5). However, students were mostly well aware of the causes and impacts that are common and direct. Students did not have a good understanding of the causes related to food production and consumption. Students also did not know how climate change can affect social issues such as conflict and war issues, or inequality in income and gender. Among the three faculties, students of the FES had a better awareness of the causes and impacts of climate change but were less aware of the actions to mitigate climate change. Internet and television/radio were the main sources of information about climate change for students (88% and 61%, respectively). This study showed that it is necessary to increase the provision of information related to climate change through the media as well as to integrate climate change knowledge into training programs at all levels from high school to university to improve the students' perceptions of climate change.
Effects of Cover Methods and Nitrogen Levels on the Growth and Yield of Tomato

Nguyen Thi Loan, Tran Thi My Can

Received: Nov 17, 2020 / Published: Aug 10, 2021
To study the effects of cover methods and nitrogen (N) levels on the growth and yield components of tomato Cv. Pear F1, field experiments with a 4x3 factorial design were conducted in the 2019 spring and winter seasons using a randomized complete block design with three replications. The cover methods included four treatments: bare soil (BS), black plastic mulch (BPM), transparent polypropylene row cover (RC), and a combination of BPM and RC (BPMRC) with the RC removed approximately 30 days after transplanting. Nitrogen (N) was applied at three levels (150, 180, and 210 kg N ha-1). Using BPM and RC generally led to an increased air temperature, air humidity, soil moisture, and soil temperature compared to the BS treatment. Higher N rates (180 and 210 kg N ha-1) did not result in different tomato fruit sizes and fruit weights but positively increased fruit yield and quality (Brix values and fruit dry weight) as compared to the 150 kg N ha-1 addition. The cover methods positively affected the yield components and fruit yield of tomato as well as the fruit characteristics compared to the BS treatment. Using cover materials (BPM and RC) combined with a higher N application significantly increased the yield attributes and fruit yield. The highest fruit yield was achieved under the mulching treatment by black plastic (BPM treatment) combined with a 210 kg N ha-1 application, resulting in 50.90 tons ha-1 in the spring and 58.27 tons ha-1 in the winter.
Study on Stem Cutting Propagation of Gynostemma Pentaphyllum (Thunb.) Makino in Hoa Binh Province

Ninh Thi Phip, Nguyen Phuong Mai, Nguyen Thi Thanh Hai, Nguyen Mai Thom

Received: Oct 28, 2020 / Published: Aug 10, 2021
Gynostemma pentaphyllum (Thunb.) Makino is a medicinal plant distributed mostly in the mountainous areas of Vietnam. G. pentaphyllum contains more than 189 types of saponin which can be used for the treatment of various diseases. Currently, due to over-exploitation, this plant species is under threaten. Our research aimed to study a suitable method for plant propagation by stem cutting techniques to promote the growth and development of G. pentaphyllum. Six experiments were conducted to (i) evaluate the established seedling rates of different G. pentaphyllum varieties, and choose the best variety to (ii) evaluate the established seedling rate influenced by different factors, viz. stem cutting position, cutting season, growing in the selected substrates, stem cutting length, number of buds per stem, and application of α-NAA. The results showed that among five varieties, G2 which was collected in Mai Chau district disclosed the highest ability to shooting, the highest number of roots per stem cutting, the shortest nursery days, the highest shooting rate, and the highestestablished seedling rate. We also determined that using middle-aged plants for stem cuttings, at 15-20cm in length, with 2 nodes and grown in Spring and Winter cropping seasons, using growing substrates with a mixture of 50% of black sand and 50% of soil, and plus α-NAA 50ppm in 3-5min produced the highest explant rate. The established seedlingsat the time of explant were 15-20cm in height, containing 4-5 leaves and at least 9-10 roots per cutting, and were 30-32 days.
Protection of Geographical Indications in Vietnam: towards Raising the Participation of Producers

Nguyen Thi Minh Hanh, Trinh Thi Ngoc Anh, Le Thi Yen, Vu Van Tuan, Nguyen Thanh Hai

Received: Oct 21, 2020 / Published: Aug 11, 2021
This paper aims to review the current situation of the Vietnamese geographical indication (GI) system from both the legal and practical perspectives. It examines how the top-down approach influences the effectiveness and sustainability of the whole system. Further, the paper refers to the European Union (EU)’s experiences, particularly those of France - a representative of the bottom-up approach - to examine whether a shift to the producer-driven approach in GIs is workable in Vietnam. The paper argues that more active roles should be vested on producers represented by their associations during the course of establishment and management of GIs. Taking into account the capacity of producers and their associations in this current stage, the paper suggests a transition period before the producers assume the leading role in the whole system. During that period, it is recommended to endorse the producers’ role through legal recognition of the producers’ representative organizations, capacity building, and awareness-raising for producers and their associations to achieve desirable outcomes for GI development.
Current Research, Challenges, and Perspectives of Biotechnology: An Overview

Nguyen Duc Bach, Ly Thi Bich Thuy

Received: Jan 04, 2019 / Published: Jan 05, 2019
Biotechnology is defined as biology-based technology using organisms or their parts to make or modify products or to improve characteristics of plants, animals, and microorganisms for the demands of human beings. Biotechnology profoundly impacts various fields such as agriculture, animal husbandry and veterinary, industry, food science, pharmaceutics and medicine, environment, fine chemistry, biofuels, forensics, and nanotechnology. Nowadays, biotechnology and bioindustries are becoming integral parts of the knowledge-based economy, and therefore, biotechnology has become a powerful and indispensable tool for the development of all countries in the world. As a rule, biotechnology also requires regulatory policies to control genetically modified organisms and derived products to avoid risks to biodiversity, human health, the environment, and ethical issues. This article reviews the current research, challenges, and perspectives of biotechnology as an integration of both life sciences and applied sciences.
Effects of Nitrogen Application on the Growth and Yield of Quinoa under Saline Conditions in Northern Vietnam

Dinh Thai Hoang, Dang Thi Phuong Anh, Luu Hue Nhan, Nguyen Viet Long

Received: Sep 06, 2020 / Published: Jun 18, 2021
This study aimed to determine the optimum nitrogen application rate for quinoa in saline soils. Two experiments were conducted: (i) the first experiment was under artificial saline conditions with the two factors of saline regime (stressed and non-stressed) and nitrogen application level (0, 30, 60, 90 and 150 kg N ha-1) in net-houses located in Gia Lam, Hanoi; and (ii) the second experiment was under natural field saline conditions with the two factors of quinoa cultivar (Atlas and Moradas) and nitrogen application level (0, 30, 60, 90, and 150 kg N ha-1) in the coastal areas of Hai Hau, Nam Dinh province. Data were collected for growth duration, insect and disease infestations during the growth period, and various growth parameters and yield components at harvest. The results showed that saline stress reduced the growth and yield parameters, but did not affect the quinoa growth duration of the investigated quinoa cultivars. In both experiments, the growth parameters and yield components increased according to the increase of the nitrogen application rates from 0 to 90 kg N ha-1, then decreased when the nitrogen rates were higher. The results suggested that 90 kg N ha-1 was the optimum nitrogen application dose for quinoa growth and development under saline soil conditions.
The Impacts of Social and Economic Determinants on Poverty: An Empirical Study on Southeast Asia

Nguyen Anh Tru

Received: Sep 02, 2021 / Accepted: Jun 27, 2022 / Published: Jun 27, 2022
The article attempted to examine the influences of social and economic determinants on poverty in seven Southeast Asian countries, namely Lao PDR, Malaysia, Myanmar, the Philippines, Thailand, Timor-Leste, and Vietnam, between 1996 and 2013 using a panel dataset. It was empirically found that the average GDP per capita and Gini index contributed to poverty reduction in Southeast Asian countries. The results also addressed that the population and poverty gap had positive impacts on the rate of the poverty headcount in the region. Policies were recommended to accelerate economic growth, reduce poverty, and achieve sustainable development in Southeast Asia. First, economic growth should be fostered since it assists in reducing poverty in Southeast Asian countries. Second, although the growth of population provides the labor forces to the economy, population growth in Southeast Asia should be carefully controlled since it increases poverty in the region. Third, an increase in the number of rich inhabitants in the society should be encouraged because it can mitigate poverty in the region. Finally, policies in redistributing income as well as in narrowing down income inequality in each society should be considered by the governments because these contribute to poverty reduction in the region.
Morphometric and meristic variability in Butis koilomatodon in estuarine and coastal areas of the Mekong Delta

Lam Thi Huyen Tran, Dinh Minh Quang

Received: Jun 08, 2020 / Published: Dec 31, 2020
The study aimed to investigate morphometric and meristic variability in the mud sleeper Butis koilomatodon (Bleeker, 1849) in the Mekong Delta. This species is a commercial fish species with a small-size and is mainly distributed in some coastal areas from Tra Vinh to Ca Mau provinces. In the present research, the parameters of morphometry and measurement, including the head length, body depth, eye diameter, distance of the two eyes, and the interrelationships among the morphometric variables, were determined. The results revealed that the total length and weight of the fish changed by sex, season, habitat, and the interaction between the seasons and habitats. Likewise, the meristic criteria were different between males and females, and the dry and wet seasons, but not by their interactions. The growth rate of males was faster than females. The outcomes also showed that the body size of this species was larger in the dry season and the largest fish were found in Duyen Hai and Tra Vinh provinces. The Findings would be useful not only for further effects of environmental factors on morphology but also for comparisons between congeners Butis morphologically.
Factors Affecting the Capacity of Accounting Software in Controlling Frauds and Errors in Small and Medium Enterprises (Smes): A Case Study of SMEs in Hanoi, Vietnam

Ngo Thi Thu Hang, Vu Thi Hai, Tran Quang Trung, Vu Manh Chien, Nguyen Thi Hong Nga

Received: Jun 13, 2020 / Published: Mar 05, 2021
Financial accounting information has impacted the operation of enterprises, especially SMEs. With the development of technology, digital accounting applications are playing an increasingly important role in minimizing mistakes, and ensuring the accuracy and timeliness of accounting information. Using multiple discriminant analyses, this study confirmed the significance of accounting software in reducing frauds and errors in SMEs’ businesses despite some drawbacks. It showed that the managers’ ability to access the software and the decentralization of power in accessing the accounting software were the two key factors deciding the success/failure of applying accounting software to control frauds and errors. In addition, smart applications of the accounting software positively contributed to the elimination of frauds in enterprises. Based on these results, recommendations are drawn for SMEs, such as investing more in smart applications of accounting software, as well as updating knowledge about accounting for management, in order to get more advantages from accounting software applications for their business in the long term.
Theoretical and Practical Issues of Research on the Consumption Needs for Safe Foods in Vietnam Using the Willingness to Pay Model

Le Thanh Ha, Nguyen Van Phuong, Do Quang Giam, Tran Quang Trung

Received: Jun 11, 2020 / Published: Mar 05, 2021
Research on consumer needs for safe foods under the willingness to pay (WTP) approach based on consumer behavior has been performed widely and has contributed greatly to the development of safe foods, assisted enterprises’ decision-making processes in improving agricultural and food products, and provided orientation to policymakers in improving public health as well as in fostering sustainable economic growth. Some of the methods used for measuring WTP for safe foods, such as contingent value (CV), choice experiment (CE), and auction experiment (AE), have made significant contributions to the evaluation of consumers’ WTP for food safety. Moreover, the application of these models has helped to estimate the effects of many factors such as demography, consumer habits, continuation of food safety, individual characteristics, promotion, and product attributes, etc., on the WTP for food safety. The trend of safe food consumption in Vietnam has distinct characteristics, some of which come from national cultural identities; therefore, Vietnamese researchers may approach the empirical studies on this issue all over the world in order to find proper methods for studying consumer needs for safe foods in Vietnam.
Comparison of Genetic Gains of Agronomical Traits from Different Selection Methods in Soybean

Vu Thi Thuy Hang, Vu Dinh Hoa, Le Thi Tuyet Cham, Nguyen Thanh Tuan, Pham Thi Ngoc, Nguyen Phuong Thao

Received: Feb 18, 2019 / Published: Mar 12, 2019
This study aimed to compare the genetic gains of two different selection methods for agronomic traits in soybean. A population from the cross of VI045032 x 4904 (LSB10) was advanced using the bulk method and modified bulk method to the F6 generation. Measured traits were growth duration, plant height, height of the first pod node, number of pods per plant, the percentage of 3-seeded pods, 100-seed weight, individual yield, and yield. Both methods were equally efficient and could be used for segregating and the stabilizing phase of progenies/populations of soybean crosses. However, the bulk method appeared to be more efficient for the improvement of yield-related traits while the modified bulk method was more efficient for the improvement of morphological traits.
Growth and Physiological Responses of Sugarcane to Drought Stress at an Early Growth Stage

Bui The Khuynh, Vu Ngoc Thang, Vu Dinh Chinh, Pham Thi Thom

Received: May 14, 2020 / Published: May 15, 2020
A pot experiment was conducted in a net house to evaluate the effects of drought stress (a 20-day water withholding treatment from 100-120 days after planting) on the growth and physiology of five sugarcane cultivars. The results showed that water stress at an early stage significantly affected sugarcane growth and physiology. Water stress resulted in reductions in plant height, stalk diameter, and leaf number of sugarcane, in addition to reductions in the photosynthetic pigment content, Fv/Fm, and SPAD (Soil Plant Analysis Development) readings after the 20-day withholding water period (120 DAP), and in stem, root, and leaf fresh weights, and leaf area at 150 DAP. Besides, drought stress led to increases in stomata density and decreases in stomata length. Variation was also found among the cultivars in response to water stress. Significant genotypic differences in stem fresh weight and leaf area under water stress among the cultivars were observed. The highest value of stem fresh weight under stressed conditions was recorded in ROC22 (50.6 g), followed by QĐ159 (46.5g), ROC16 (46.2g), ROC10 (46.1g), and VL06 (44.4g). However, the highest DTI was recorded in ROC16, followed by VL06, ROC10, QĐ93-159, and ROC22, respectively.
The Effects of Short Freshwater Bath Treatments on the Susceptibility to Different Stages of Neobenedenia girellae Infecting Barramundi (Lates calcarifer)

Truong Dinh Hoai, Trinh Thi Trang, Nguyen Thi Huong Giang

Received: Jun 09, 2019 / Published: Dec 24, 2019
Neobenedenia girellae is one of the most pathogenic parasites affecting marine fish in captivity conditions. The use of chemicals for parasite prevention and treatment have several benefits; however, they can cause various negative side-effects. In an effort to discover cost-effective and sustainable practices, our current study was aimed at investigating the efficiency of freshwater treatments on N. girellae. A challenge test was conducted to produce infected fish which became materials for the freshwater immersion experiments. The duration and reaction of the parasites at different development stages from eggs to adult parasites were examined. Our findings revealed that 100% of the adults and oncomiracidia of N. girellae were killed quickly in freshwater. The eggs of N. girellae, however, were highly resistant to freshwater with a hatching success rate of more than 95% in all the freshwater immersion treatments (2, 5, 10 and 30min). The eggs hatched mainly on day 7 and finished hatching on day 8. Thus, the freshwater immersion method can be applied to treat N. girellae at most stages excepted for the egg stage. The best practical treatment for this parasite is to perform a replicated immersion recommended 8 days following the first treatment.
The Framework of Ecosystem Services for Economic Valuation Purposes: A Review

Nguyen Minh Duc

Received: Dec 25, 2018 / Published: Dec 24, 2019
Although humans need ecosystems and ecosystem services for their survival and well-being, most of the global ecosystems and the services that they provide have declined and/or degraded rapidly over the past few decades. In order to find the ways to sustainably use natural resources, substantial efforts have been made to measure and value the ecosystem services. The term ‘ecosystem service’ was interpreted in different ways in the literature. For making correct decisions in natural resource management, a consistent way of defining and classifying ecosystem services is needed for valuation purposes. This paper argued for the need to divide ecosystem services into intermediate and final services.
Identification, Structural Analysis, and Expression Profile of Genes Related to Starch Metabolism in Cassava (Manihot esculenta Crantz)

Chu Duc Ha, Nguyen Van Loc, Lai Thi Uyen, Pham Phuong Thu, Pham Thi Ly Thu

Received: Jun 15, 2019 / Published: Aug 30, 2019
Starch metabolism is known to be an important pathway in the growth and development of plants. This study was conducted to investigate the genome-wide identification and structural analysis of genes encoding uridine diphosphate glucose pyrophosphorylase (UGPase), a key enzyme in starch synthesis in cassava, and to analyze the expression profiles of these genes based on publicly available RNA-seq data. A total of 11 members were found in the UGPase gene family (MeUGP) in cassava. Ten of the MeUGP genes were successfully mapped onto the chromosomes of the current cassava genome assembly. Based on their nucleotide sequences, the lengths of the genomic DNA sequences of the MeUGP genes ranged from 3,200 to 11,601bp, while the size of the coding sequence (CDS) varied from 831 to 3,654bp. According to the recent RNA-seq data, we found that a majority of the MeUGP genes were expressed in at least 1 tissue under normal conditions. Interestingly, MeUGP4 was greatly expressed in the shoot apical meristem, while MeUGP10 was more specific in the root apical meristem. The expression profiles of these MeUGP genes should be carried out in various conditions in further studies.
Effects of Organic Fertilizer and HB101 Plant Vitalizer on the Growth and Yield of Rice (Oryza sativa L.)

Nguyen Thi Loan, Nguyen Ngoc Hung

Received: Jun 14, 2019 / Published: Aug 30, 2019
To study the effects of organic fertilizer and HB101 organic plant vitalizer on the growth and yield components of the BH9 rice variety, a field experiment with 4 x 3 factorial design was conducted at Hong Thai commune, Kien Xuong district, Thai Binh province in 2017 summer season using a randomized complete block design with 3 replications. Organic fertilizer derived from chicken manure and peat was applied at 3 levels (0 ton ha-1, 4 tons ha-1, and 6 tons ha-1) while the HB101 plant vitalizer was sprayed in 4 levels (0%, 0.015%, 0.025%, and 0.035%; the amount of water to dilute HB101 was 1000 litre ha-1). The application of the organic fertilizer alone and the combination of organic fertilizer and HB101 positively increased the total tiller number, effective tiller number, leaf area index (LAI), SPAD value, dry matter accumulation, yield components, and grain yield of rice. There were also differences in the SPAD values (at flowering stage), dry matter weight (at active tillering stage), and 1000 grain weight under the influence of the HB101 solution. The combination of 6 tons ha-1 organic fertilizer and HB101 significantly increased the grain yield as compared to the other treatments, and the highest grain yield (3.03 tons ha-1) was obtained when organic fertilizer (6 tons ha-1) was applied in combination with HB101 plant vitalizer (0.025%).

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