Vol. 5 No. 1 (2022): Vietnam Journal of Agricultural Sciences

Seed-borne rice endophytes are capable of disseminating into host plant tissues as well as to their rhizosphere. Here, we investigated the occurrence of siderophore-producing bacteria (SPB) in the seed endospheres of two distinct rice (Oryza sativa L.) cultivars, TK8 (ssp. japonica) and TCN1 (ssp. indica), and their dissemination into the rhizospheres through culture-dependent methods. Their patterns of occurrence in the rhizospheres as well as in the root and shoot tissues of 30 day-old cultivars grown in three different kinds of soils were tested. The significance of SPB on Fe sequestration of TCN1 was studied using Enterobacter sp. LS-756. TK8 seeds were found to be not only abundant in endopsheric SPB (> 10-fold), but also exhibited enhanced SPB dissemination into the rhizosphere (1.3-fold) as compared to TCN1. The proportion of endophytic SPB was consistently higher in roots than in shoots, and it was found to decline with decreasing soil pH. A similar declining trend was further evident through the analysis of SPB composition in the rhizospheric and bulk soils. LS-756-inoculated TCN1 seedlings under low availability of Fe showed 32%, 178%, and 368% increases in Fe, chlorophyll, and chlorophyll b contents as compared to the uninoculated controls. Thus, the occurrence of seed-borne endophytic SPB and their dissemination into the rhizosphere vary significantly according to the rice genotype. Higher co-occurrence of SPB in the rhizosphere and internal root tissues of rice plants grown under Fe-limited conditions and the enhanced Fe uptake due to SPB inoculation substantiated their potential involvement in Fe sequestration.

Salinity is one of the most devastating abiotic stresses limiting crop production. Considering this issue, a pot experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the boro season (2017-2018) using two rice(Oryza sativa L.) varieties, namely BRRI dhan28 (salt sensitive) and BRRI dhan47 (salt tolerant),to assess the effects of varied salinity levels on the growth and the performance of the rice varieties under salt stress conditions. Four salinity treatments were used in this experiment, viz. control S0 (only freshwater), quarter-strength marine water S1 (three-parts freshwater and one-part marine water; 7.5 ds m−1), half-strength marine water S2 (half freshwater and half marine water; 15 ds m−1), and full-strength marine water S3 (only marine water; 30 ds m−1).These mixtures were used for irrigation purposes throughout the life cycle of the plants. Salt stress significantly decreased the plant height, relative water content (RWC) of leaves, number of effective tillers hill−1, number of filled grains panicle−1, 1000-grain weight, grain yield, straw yield, and biological yield of the rice. In both rice types, plant growth and yield were reduced as the salinity level increased. Grain yields decreased by 50, 90, and 100% in BRRI dhan28 when irrigated with quarter strength, half strength, and full-strength seawater, respectively, but decreased by 27, 50, and 72%, respectively, in BRRI dhan47. Similarly, other yield attributes had higher reductions in BRRI dhan28 under salt stress conditions than BRRI dhan47. However, irrigation with marine water in rice might lead to some straw yield but produced little to no grain.

This study aimed to investigate the current use of drugs, chemicals, herbs, and herbal extract products in grow-out farms of snakehead (Channa striata) and Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. The survey was conducted with a total of 60 Pangasius catfish grow-out farms in An Giang and Dong Thap provinces, and 60 snakehead grow-out farms in An Giang and Tra Vinh provinces. The results showed that bacterial diseases were commonly reported by snakehead farmers (1-4 episodes per crop) and Pangasius catfish farmers (1 to 12 episodes per crop). Farmers used 12 types of single antibiotics and a mixture of two antibiotics in Pangasius catfish, and eight types of antibiotics in snakehead aquaculture. However, Pangasius catfish and snakehead farmers used enrofloxacin and ciprofloxacin, which are banned antibiotics according to the Vietnamese authority regulations. For the use of herbs and herbal extract products, a variety of commercial products were used by farmers which claimed different purposes for use. According to the farmers, the quality and effectiveness of these products were questionable. Some farmers used traditional herbs following their experiences using traditional medicines for humans and did not really know about the application doses. Thus, it would be requested for in-depth studies on the use of herbs as on-farm treatments, which would provide evidence for the use of herbs in the industry.

Sustainable forest management is facing threats such as deforestation, forest degradation, and biodiversity loss due to socio-economic conditions, a weak governance capacity, and lack of public participation. In Xuan Nha Nature Reserve, about 50% of the total population are living below the poverty level and  their livelihoods are depending on forest. The community’s activities have been creating pressures on the forest by reducing the forest area, increasing forest land degradation, and through illegal logging. The objectives of the study were to (i) identify sustainable livelihood options; (ii) the most suitable livelihood practices with the purpose of reducing poverty for local communities and their dependency on forest resources; and (iii) recommend suitable policies to reduce the conflict between socio-economic development and forest management. In order to achieve these objectives, we used the LIFE (livelihood, income, forest condition, and equity); the Sustainable Livelihood Framework; and the Advocacy Coalition Framework. The results showed that fruit orchards and beekeeping were two suitable livelihood options for the buffer areas since there were more convenient assets such as roads, markets, and human knowledge, while fruit orchards and local pig farming were suggested for the ERA (ecological restoration area) and SPA (strictly protected area) to solve the problem of land degradation and maintain the traditional habits of the local community. Regarding policy changes, support for livelihood practices and improvement of the community’s and authorities’ awareness on forest protection was necessary for all the sub-areas for reducing poverty and the pressures on forest resources of the community.

This research aimed at assessing climate trends and adaptation strategies to the impacts of climate change on rice producers in Nghe An province. For the first objective, multiple graphs, the Mann–Kendall test, and Sen’s Slope test were employed to analyze the secondary data of rainfall, temperature, and rice yield in Nghe An from 1995 to 2019. The results showed that the rice productivity of Nghe An increased over the 25-year period, annual rainfall decreased in the winter-spring season, and annual temperature increased in the summer-autumn season. For the second objective, primary data were collected by conducting household surveys of 396 households in Nghe An province. Sixty-two percent of farmers did not adopt any adaptive strategies, while other strategies included changing the planting schedule, growing stress-tolerant crops, improving irrigation practices, and utilizing fertilizer and other good practices. Multivariate probit regression (MVP) was employed to analyze the factors affecting the adaptation strategies of households in the study area. The results of MVP showed that age, education, gender, household size, farm size, cooperative, farmer organization, extension services, access to credit, access to irrigation, rainfall, and living in Quynh Luu or Dien Chau significantly affected the farmers’ choice. The results implied that farmers can obtain advanced technology, social learning, and community practices by participating in farmer organizations and cooperatives. In specified area, local authorities should invest in improving irrigation systems, practicing land consolidation, practicing special farming techniques, and providing timely weather forecasts for enhancing farmers’ resilience. 

The purpose of this study was to determine the phytochemical compositions and to evaluate the biological activity of the stem bark of Dialium cochinchinense. The phytochemical analysis showed the presence of steroids, terpenoids, anthraquinones, saponins, and phenolics in the stem bark of D. cochinchinense. The optimal extraction conditions were 70% ethanol at 30°C for 40min with a material/solvent ratio of 1/20. Under the optimal conditions, the corresponding predicted response value for the total phenolic content was 100.80 ± 0.40 mg GAE/g DW. The evaluation of antioxidant activity indicated that the polyphenol-rich extract was a good source of antioxidants as measured by the DPPH assay with the IC50 of 3.81 ± 0.58 μg mL-1. The extract also demonstrated a strong a-glucosidase inhibitory activity with the IC50 value of 2.14 ± 0.05 μg/mL. Therefore, D. cochinchinense could be useful as a potential preventive intervention for free radicals in mediated diseases as well as an antioxidant drug and a potential source in treating diabetes mellitus in the pharmaceutical industry.

The Siraha district of Nepal experiences surplus mango production during the season that ends up being wasted or sold at throw-away prices due to imperfect marketing. Thus, this survey research was conducted to investigate the market channels of mango, post-harvest mechanisms, constraints, marketing margins, market shares, consumer purchasing behaviors, and patterns of purchasing in Siraha.The research survey was done with thirty producers, five wholesalers, thirty-two retailers, and twenty-five consumers within the Golbazaar and Dhangadimai municipalities through a semi-structured questionnaire. Mango trading was dominated by males. It was revealed that the market demand for mango in Siraha was produced in Siraha itself(91.49%). The wholesalers supplied 30.66% of their mango to retailers, and 14.73% to consumers. Gulab Khas and Banaganapalli were the most imported varieties from India. Each variety of mango provided an almost equal margin, although Bombay was slightly higher than others. The market share was dominated by the Maldah variety as most of the farmers cultivated this variety.It was found that in addition to the varieties and arrival time, the distance to markets and farming practices were significant factors influencing the profitability of mango marketing. There is great potential to industrialize and substitute the Indian mango in the market through commercial production of mango, efficient storage, and post-harvest management, and in increasing the efficiency of the mango marketing system through subsidies and aids to the mango growing farmers from concerned stakeholders. A collaborative approach is required among all stakeholders for sustainable mango marketing and establishing it as an economic profession.

The objective of the paper was to analyze the factors influencing the purchase intention of consumers for imported beef in Long Bien district, Hanoi. Quantitative and qualitative methods were employed in this study based on an online survey using a structured questionnaire. The data were collected from 388 consumers who bought imported beef or had an intent to buy in the future. Structural equation modeling (SEM) was used to analyze the data. The results of this study showed that the factor of perceived quality and the factor of clear information on the packaging with the country of origin were the significant factors that increased purchase intention. These factors also contributed to increasing the positive attitudes towards the consumption of imported beef. Attitudes were also a mediating factor that positively influenced purchase intention. In addition, the availability of the product in the market contributed to the stronger purchase intention towards imported beef.

Tomato (Solanum lycopersicum) is known as the most important vegetable crop that is widely cultivated throughout the world. Improvements of the growth, development, and productivity have become core strategies for the sustainable development of tomato in many countries. Here, we performed an intensive summary of recent applications of genome editing in customizing the growth habits and fruit quality in tomato plants. First, the advantages of genome editing, particularly CRISPR/Cas systems, were introduced. We then summarized all up-to-date studies related to the genome editing-based functional characterization of genes of interest in tomato with the aim of designing the growth habits and enhancing the fruit quality. Finally, we discussed the potential applications of this promising tool in tomato breeding programs in Vietnam. Taken together, our review has provided a wide view for further studies towards improving the growth, development, and productivity of tomato in Vietnam.