Ben Tre Province Research Articles

Deciphering the relationship between meteorological and hydrological drought in Ben Tre province, Vietnam

Deciphering the relationship between meteorological and hydrological drought in Ben Tre province, Vietnam

Application of heat pump drying technology to produce dried mango products from Tu Quy mango (Mangifera india L.), Vietnam, on a pilot scale

In this study, the heat pump drying technique was applied to develop the production process of dried mango from Tu Quy mango sources, Ben Tre province, Vietnam. The experiment was performed in three steps. First, mango slices were treated through the blanching process. Samples were pretreated with sizes from 6 to 12 mm at 80–95°C for 3–6 min, and then the mango slices were soaked in a syrup solution concentration range of 25–40°Bx, citric acid of 0.5–2%, and glycerol of 0.1–0.4% at 35–65°C for 90–180 min. Finally, the samples were dried using a pilot-scale heat pump dryer until the moisture content reached 14–16%. The results showed that the blanching and osmosis processes were carried out under optimal conditions to inactivate the Polyphenol oxidase (PPO) enzyme, obtain maximum polyphenol compounds, and conform to the product appearance. Additionally, the drying process was carried out at 30°C for 1,080 min with the polyphenol content retaining 11.71 mgGAE/gDW—This signifies a successful endeavor in developing production methodologies and expanding the range of mango-derived products. Employing innovative technological processes enhances both the quantity and quality of the products. Moreover, the manufacturing procedure was executed on a pilot device, streamlining the synchronization of large-scale production processes effortlessly. This advancement not only enhances economic value but also addresses the issue of congestion prevalent in the current state of the mango industry in Vietnam.

Extent of saltwater intrusion and freshwater exploitability in the coastal Vietnamese Mekong Delta assessed by gauging records and numerical simulations

Climate change-driven sea level rise has intensified salinity intrusion (SI) in deltas worldwide, posing significant threats to the exploitation of freshwater resources. In the Vietnamese Mekong Delta (VMD), the third largest delta globally, SI is a recurring challenge along the coastline, degrading freshwater resources for agricultural and domestic use and affecting socio-economic development. In this paper, we investigate the spatiotemporal extent of salinity intrusion in the Ben Tre Province, the hotspot of salinity disaster within the VMD. Long-term salinity monitoring data (25 years from 1996 to 2020) has been analyzed, and a 1D (Mike 11) coupled with 3D hydrodynamic model (Mike 3) was developed. Three scenarios were used to investigate the freshwater resources exploitation: (i) the year of investigation (2021), (ii) 2021 to 2030 climate change impacts, considering different annual exceedance probability of the upstream Mekong discharge (i.e., average flow, relatively low, low and very low), and (iii) extreme salinity intrusion (i.e., the 2016 condition). Our results indicated that salinity patterns are well-stratified at the beginning and end of the dry season but well-mixed during the middle period. Furthermore, over the last 25 years, SI has progressively increased and started earlier in the dry season. The modeling scenarios for SI have also revealed a growing complexity in the exploitation of freshwater resources, highlighting challenges related to timing, depth, and geographical location. The exceedance probability scenarios disclosed higher and deeper salinity intrusion along the channel in VMD, ranging from 50 % to 95 %. This poses significant limitations on the feasibility of freshwater exploitation throughout the Ben Tre Province. Under the current trajectory of climate change, the 2030 scenario anticipates salinity intrusion reaching further inland from the 2021 scenario. This is likely to exacerbate the existing challenges in freshwater resource exploitation, even with comprehensive water infrastructure. We, therefore, propose several management strategies to adapt to salinity intrusion: storing freshwater in main rivers, maintaining consistent operation of water infrastructure systems, and encouraging water-saving distribution and exploitation methods. Moreover, we also recommend supporting the development of new drought-tolerant crop patterns.

Enhancing Soil Stabilization in Soft Soils Through The Addition of Sand to Soil-Cement Piles: a Comprehensive Study

Applying a soil-cement mixture to treat soft soil is an effective solution and is being widely applied in many countries around the world. In Vietnam, this method has also been used in many projects, especially in areas with weak soil such as riverside and coastal areas. The soil-cement mixture is made up of natural soil and cement. When cement is mixed with soil, the cement particles will react with water and minerals in the soil, forming a hard bond. The polymerization of this material is equivalent to the curing time of cement. This article focuses on researching the mixing of soil and cement materials to reinforce weak soil in Ben Tre province. Instead of just using cement for reinforcement, the article suggests adding sand and ECO-CSB or ECO-CSSB additives to the soil-cement mixture. Experimental results show that when sand and additives are added, the hardness and load-bearing capacity of the soft ground increase significantly. This method is especially suitable for treating soft soil contaminated with salinity in Ben Tre province. When adding ECO-CSB additives for non-saline soils and ECO-CSSB for saline soils, the amount of cement needed is reduced by 30% while still ensuring uniaxial compressive strength compared to when using only cement.

Explicating internet usage among farmer households: evidence from Ben Tre Province, Vietnam

Explicating internet usage among farmer households: evidence from Ben Tre Province, Vietnam

Characterization and molecular identification of the lumpy skin disease virus in cattle in the Mekong Delta of Vietnam.

Lumpy skin disease (LSD) is caused by a virus belonging to the genus Capripoxvirus, exhibiting clinical symptoms ranging from mild signs to the development of nodules. LSD emerged in Asia and Southeast Asia, including Vietnam, in October 2020 and has since spread throughout the region, resulting in productivity and economic losses. This study aimed to investigate the virus-causing papular dermatitis in cattle from the Mekong Delta region of Vietnam by analyzing its GPCR gene and assessing its evolutionary relationship with sequences in the GenBank database. Blood samples (n = 180) were collected from cattle farms in Ben Tre, Tien Giang, and Tra Vinh provinces. PCR targeting the P32 antigen gene was utilized to detect LSDV presence, and GPCR gene amplification was performed to assess genetic variability. LSDV was detected in 8.33% (15/180) of the samples using PCR targeting the P32 antigen gene. Each sample that tested positive for LSDV demonstrated complete amplification of the GPCR gene. Sequence alignments and phylogenetic analyses of the GPCR gene revealed that Mekong Delta LSDV isolates shared genetic similarities and possessed a 12-nucleotide insertion comparable to strains from China in 2019 and Northern Vietnam in 2020. This study provides preliminary insights into the molecular characteristics of LSDV in cattle from the Mekong Delta region of Vietnam. The observed genetic relatedness to other LSDV sequences from Asia and Southeast Asia underscores the importance of regional surveillance and control measures. These findings contribute to the development of effective strategies for LSDV control and prevention.

Hydrodistillation of essential oil from peels of orange (Citrus sinensis) in the Mekong Delta, Vietnam: process optimization and chemical profiling

In this study, essential oils were extracted from peels of orange (Citrus sinensis) by employing hydrodistillation. The materials were collected in Ben Tre Province, Vietnam and the process was optimized by varying some experimental parameters including temperature, water-to-material ratio, extraction time and material size. The obtained essential oil was analyzed by Gas Chromatography-Mass Spectrometry to determine chemical composition. The maximal essential oil yield was determined as approximately 4%, obtained at the following conditions: ratio of water and lemon peels of 3:1 (mL/g), 60 mins and130°C. GC-MS results revealed that Limonene (98.454%), β-Myrcene (0.997%), and α-Pinene (0.549%) are the major constituents in the essential oil.

Utilizing a settling pond-based constructed wetland for the treatment of shrimp aquaculture wastewater – From laboratory to field scale: A case study in Ben Tre Province, Vietnam

The shrimp aquaculture industry, while bringing high economic benefits, simultaneously presents many environmental challenges for many countries, including Vietnam. Our survey results regarding shrimp farming management in 30 representative rural households within Ben Tre province have revealed that 96.7% of wastewater does not meet the allowable standards. Although approximately 76.66% of which is crudely treated by settling ponds, the percentage of substandard wastewater is reduced only to 70%. Unfortunately, >93% of the wastewater is discharged directly into the environment. Faced with that situation, a proposed wastewater treatment option suitable for the rural areas is to utilize settling ponds and indigenous reeds (P.australis and P.vallatoria) to build constructed wetlands (CW). A lab-scale CW was designed to mimic a settling pond on the surveyed farm, which was scaled down to a ratio of 1:500, aiming to validate the efficacy of the CW approach. Accordingly, the P.vallatoria-planted CW with a density of 25 roots/m2 effectively treats the wastewater to meet the permissible standard within 4 weeks. The removal efficiencies of organics, nutrients, heavy metals, and total coliform could reach up to 80, 85, 91, and 41%, respectively. Upon transitioning to the field scale, these efficiencies increased up to 13.09, 18.79, 29.47, and 5%, respectively. More importantly, the treatment time could be shortened to 3 and 2 weeks, respectively, when the wastewater is diluted 1.5 and 3 times, thereby serving as a foundation to upgrade the current farming model from intensive to super-intensive.

Polyphenol Contents, Gas Chromatography-Mass Spectrometry (GC-MS) and Antibacterial Activity of Methanol Extract and Fractions of Sonneratia Caseolaris Fruits from Ben Tre Province in Vietnam.

Plants contain a large number of phytochemical components, many of which are known as bioactive compounds and responsible for the expression of various pharmacological activities. The extract of Sonneratia caseolaris fruit collected in Vietnam was investigated for its total phenolic and total flavonoid contents using methanol solvent and different fractions of S. caseolaris fruits (hexane, ethyl acetate, n-butanol, and aqueous). GC-MS analysis was conducted to identify the bioactive chemical constituents occurring in the active extract. Further, the antibacterial activity was tested in vitro on bacterial isolates, namely Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, using the disc diffusion method on tryptic soya agar (TSA) medium. The methanol extract showed high total flavonoid (82.3 ± 0.41 mg QE/g extract) and phenolic (41.0 ± 0.34 mg GAE/g extract) content. GC-MS of the methanol extract and different fractions of S. caseolaris fruits detected 20 compounds, principally fatty alcohols, fatty acids, phenols, lipids, terpenes derivatives, and carboxylic acids derivatives. A 50 mg/ml concentration of methanol extract had the strongest antibacterial activity on E. coli, S. aureus, and B. subtilis. Furthermore, ethyl acetate, aqueous, and n-butanol fractions inhibited S. aureus and B. subtilis the most. The results of the present study suggested that the fruits of S. caseolaris are rich sources of phenolic compounds that can contribute to safe and cost-effective treatments.

Using Trichoderma asperellum to Antagonize Lasiodiplodia theobromae Causing Stem-End Rot Disease on Pomelo (Citrus maxima).

Stem-end rot disease has been causing damage to the production of pomelos in Vietnam. The cur-rent study aimed to (i) isolate fungal pathogens causing pomelo stem-end rot disease (PSERD) and (ii) discover Trichoderma spp. that had an antagonistic ability against pathogens under in vitro conditions. Fungi causing PSERD were isolated from pomelo fruits with symptoms of stem-end rot disease and collected from pomelo farms in Ben Tre province, Vietnam. Moreover, 50 fungal strains of Trichoderma spp. also originated from soils of these pomelo farms in Ben Tre province and were dual-tested with the fungal pathogen on the PDA medium. The results demonstrated that 11 pathogenic fungi causing PSERD were isolated from the fruit and showed mycelial growth of roughly 5.33-8.77 cm diameter at 72 h after inoculation. The two fungi that exhibited the fast-est growth, namely, S-P06 and S-P07, were selected. ITS sequencing of the S-P06 and S-P07 fungi resulted in Lasiodiplodia theobromae. All the 50 Trichoderma spp. strains were allowed to antago-nize against the S-P06 and S-P07 strains under in vitro conditions. The greatest antagonistic effi-ciency was found in Trichoderma spp. T-SP19 at 85.4-86.2% and T-SP32 at 84.7-85.4%. The two antagonists were identified as Trichoderma asperellum T-SP19 and T-SP32. The selected strains of Trichoderma asperellum were potent as a biological control for fruit plants.

Evaluation of the current status of wastewater management and treatment from super-intensive whiteleg (Penaeus vannamei) shrimp ponds in Ben Tre Province

Evaluation of the current status of wastewater management and treatment from super-intensive whiteleg (Penaeus vannamei) shrimp ponds in Ben Tre Province

Assessment of soil-water vulnerability to salinization in Ben Tre province using DRASTIC model

Soil water in the coastal zones is more vulnerable to salinization. Soil-water vulnerability assessment is an effective tool for soil-water management. This study used the DRASTIC model, which is based on seven factors viz: depth to soil water, recharge, soil-water bearing layer, soil media, topography, impact of root zone, and hydraulic conductivity to evaluate soil-water salinization potentiality of Ben Tre province. The obtained soil-water vulnerability map is divided into three vulnerable zones: low vulnerability zone with 348.59 km2 of total area, moderate vulnerability zone with 1898.77 km2, and high vulnerability zone having 147.64 km2. Moreover, the DRASTIC model was validated by Total dissolved solids (TDS) over the study area. Validation results showed the low vulnerability zone of the moderate saline (TDS = 1,500–7,000 mg/L), while the moderate vulnerability zone of the moderate, high, and very high saline (TDS = 1,500–35,000 mg/L). However, the high vulnerability zone has a very high saline (TDS = 15,000–35,000 mg/L). The study results are of considerable value to land use planning and soil researchers.

Maritime security or economic growth: The choice of stakeholders in coastal tourism development in Binh Dai district, Ben Tre province, Vietnam

Coastal tourism emerges as a diverse, dynamic, fast-growing, and economically attractive form of contemporary tourism that encompasses a range of tourism, leisure- and recreational-oriented facilities and activities. As the coastline resembles a composite of ecological, social cultural, and economic values, it is of considerable interest to people, processes, and industries. Vietnam possesses the strategic advantage of a vast coastline spanning the entire length of the country, coupled with its location within the language zone of the East Sea, a crucial trading route for global commerce. Alongside the exploitation of marine resources, oil and gas, transportation, and port services, the development of coastal tourism is deemed a critical sector in promoting the growth of the maritime economy. Nevertheless, due to the national strategic position, the development of tourism in coastal areas faces challenges in reconciling national security policies for coastal defense with the goal of promoting economic development. This article examines the implementation of maritime economic development policies in Binh Dai district, Ben Tre province, highlighting a strategic balance between maintaining maritime security and promoting economic development for stakeholders. The study reveals that sustainable development in coastal tourism is not solely concerned with the livelihoods of local communities and environmental protection, which are typical concerns in other forms of tourism, rather, in the context of Binh Dai district, Ben Tre province, it is also tightly linked to maritime security.

Cost-benefit analysis of migration in the context of environmental change in Ben Tre Province of Viet Nam

Changes in the natural environment and the socio-economic environment have had both direct and indirect impacts on agricultural production and farmer’s life in three coastal districts of Ben Tre Province of Viet Nam, including Binh Dai, Ba Tri, and Thanh Phu. Natural environment changes are drought, saline intrusion, and landslides while the socio-economic environment changes consist of agricultural market fluctuation, rising labor and agricultural input price, decreasing output price, diseases, etc. One of the solutions that households take to cope with these changes is migration. In this article, the authors examine factors that affected households’ migrating decisions and behaviors using cost-benefit approach. Two research methods used in this study are social surveys and in-depth interviews. The survey was conducted with 79 households that have migrants in 3 coastal districts. The research suggests that migrants themselves made the migration decision in most cases (85%). Three main reasons for migration among farmers in the area have been identified as (1) solving the immediate difficulties of the household, (2) being part of the family’s long-term plan, and (3) being the family’s livelihood strategy in the short term (solving difficulties) and long-term (transforming livelihoods). The costs that migrants and their families can face are direct costs (packing, travel costs, rental housing, etc.) and indirect costs (change in living environment and social relations, anxiety of family members, and social evils at the destination, etc.). The benefits of migration can be immediate benefits (economic and non-economic) as well as long-term effects that have a great impact on household life and the migrants themselves. The research finds that migration provided more benefits related to the living conditions of households. It also points out that migration has become a feasible long-term adaptation strategy for farmers, those who stayed behind, in the context of environmental change.

Extracting Land-Cover Information from Landsat Satellite Images by the Decision-Tree Model to Generate a Land-Use Map in Ba Tri District, Ben Tre Province

Extracting Land-Cover Information from Landsat Satellite Images by the Decision-Tree Model to Generate a Land-Use Map in Ba Tri District, Ben Tre Province

Factors Affecting Tourist’s Decision to Choose Homestay in Ben Tre Province

Factors Affecting Tourist’s Decision to Choose Homestay in Ben Tre Province

Assessing Climate-Driven Salinity Intrusion through Water Accounting: A Case Study in Ben Tre Province for More Sustainable Water Management Plans

This scientific paper delves into sustainable water management strategies for Ben Tre Province of the Vietnamese Mekong Delta (VMD) in light of water-infrastructure plans that have been impacted by climate change-induced salinity intrusion. Specifically, we aim to mitigate the effects of salinity intrusion for the province while promoting long-term environmental sustainability. In doing so, a water accounting framework was applied, mostly based on the MIKE11 hydrodynamic modeling and water balance calculations, to determine current and future water stress issues based on two main scenarios of extreme drought year 2016 (baseline) and the future year 2030 under climate change for a medium-low emission scenario (RCP4.5). The study found that salinity intrusion significantly causes severe water stress in the future year 2030 compared to the baseline year 2016, while the existing water management methods are relatively inadequate to control salinity intrusion, leading to over 57% of the area affected by medium to critical water stress levels, although it will go along with planned water infrastructures. Additionally, a system of triple rice cropping converted two rice cropping and upland cropping with 40% water demand cutoff was found to be the most suitable measure for 2030. Particularly, water-saving and water demand reduction should be incorporated into infrastructural planning for sustainable water management. Our study provides valuable insights for policymakers and stakeholders, not only for the province and the VMD, but also other regions facing similar challenges.

Soil salinity prediction using hybrid machine learning and remote sensing in Ben Tre province on Vietnam's Mekong River Delta.

Soil salinization is considered one of the disasters that have significant effects on agricultural activities in many parts of the world, particularly in the context of climate change and sea level rise. This problem has become increasingly essential and severe in the Mekong River Delta of Vietnam. Therefore, soil salinity monitoring and assessment are critical to building appropriate strategies to develop agricultural activities. This study aims to develop a low-cost method based on machine learning and remote sensing to map soil salinity in Ben Tre province, which is located in Vietnam's Mekong River Delta. This objective was achieved by using six machine learning algorithms, including Xgboost (XGR), sparrow search algorithm (SSA), bird swarm algorithm (BSA), moth search algorithm (MSA), Harris hawk optimization (HHO), grasshopper optimization algorithm (GOA), particle swarm optimization algorithm (PSO), and 43 factors extracted from remote sensing images. Various indices were used, namely, root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2) to estimate the efficiency of the prediction models. The results show that six optimization algorithms successfully improved XGR model performance with an R2 value of more than 0.98. Among the proposed models, the XGR-HHO model was better than the other models with a value of R2 of 0.99 and a value of RMSE of 0.051, by XGR-GOA (R2 = 0.931, RMSE = 0.055), XGR-MSA (R2 = 0.928, RMSE = 0.06), XGR-BSA (R2 = 0.926, RMSE = 0.062), XGR-SSA (R2 = 0.917, 0.07), XGR-PSO (R2 = 0.916, RMSE = 0.08), XGR (R2 = 0.867, RMSE = 0.1), CatBoost (R2 = 0.78, RMSE = 0.12), and RF (R2 = 0.75, RMSE = 0.19), respectively. These proposed models have surpassed the reference models (CatBoost and random forest). The results indicated that the soils in the eastern areas of Ben Tre province are more saline than in the western areas. The results of this study highlighted the effectiveness of using hybrid machine learning and remote sensing in soil salinity monitoring. The finding of this study provides essential tools to support farmers and policymakers in selecting appropriate crop types in the context of climate change to ensure food security.

Synthesis and field experiments of the female sex pheromone of sweet potato weevil, Cylas formicarius

Abstract. (Z)-3-dodecen-1-yl (E)-2-butenoate (1) identified as the sex pheromone of sweet potato weevil, Cylas formicarius Fabricius, had been synthesized successfully from 3-butyn-1-ol and 1‑bromooctane as the starting materials. The overall yield via four steps was 60% calculated on 3-butyn-1-ol. The primary step of the scheme was the stereoselective reduction reaction for alkyne cis-hydrogenation without using molecular hydrogen by Pd2(dba)3-catalyzed. And, this reaction was carried out efficiently with KOH/DMF as the hydrogen source. Next, the field trapping experiments were conducted from February to June 2021 at Tien Thuy ward - Chau Thanh district (Ben Tre province) to develop a simple, easy to construct, cost‐effective, and efficient sex pheromone‐baited trap. Main experiments have given positive results such as the relative to sweet-potato foliage, the trap designs, doses of pheromone lure from 0.1 mg to 0.8 mg, and the effect of lure traps with a dose of 0.4 mg. These values can use well to control the dosage of pheromone in field experiments. Keywords: (Z)-3-dodecen-1-yl (E)-2-butenoate, Cylas formicarius Fabricius, Pd2(dba)3/KOH/DMF, 1-decyne, 1-bromooctane, 3-butyn-1-ol, (Z)-configuration, the average number of captured individuals, sweet potato weevil.

Evaluating Coastal Surface Water Quality in Ben Tre Province, Vietnam

Evaluating Coastal Surface Water Quality in Ben Tre Province, Vietnam