Vietnam Journal of Agricultural Sciences

This study aimed to evaluate the effects of chemical and organic fertilizers in different fertilization regimes on vegetative growth, fruit yield, and fruit quality of tomatoes. The experiment was arranged in a randomized complete block design with three replications in the winter season of 2021. The treatments were: no fertilizers, application of NPK fertilizer (15-15-15) at a rate of 1000 kg ha-1, application of chicken manure at a rate of 12 tons ha-1, and three treatments of the combination of NPK fertilizer and chicken manure at the ratios of 70:30, 50:50, and 30:70, respectively. The results indicated that the combination of chemical and organic fertilizers led to improved vegetative plant growth. Combining 70% of NPK fertilizer with 30% of chicken manure gave the maximum fruit yield component values and fruit yield of tomatoes. Adding chicken manure to the fertilization regimes also led to better fruit quality. The integrated fertilization increased the TSS and vitamin C values, and when 50-70% of the chemical fertilizers were substituted with chicken manure, the sugar content and total acid increased in the fruits. The color at the red stage was more intense in tomato fruits treated with the NPK fertilizer and integrated fertilization regimes compared to those from organic fertilization.

Jiaogulan (Gynostemma pentaphyllum (Thunb.) Makino) is distributed mostly in mountainous areas, in shaded and humid places at 300-3200 meters above sea level. This study was conducted to determine the appropriate application dose of nitrogen for the growth of Jiaogulan under different shading conditions. The experiment was arranged in a split-plot design with three replications in 2021. Nitrogen application dose was the main factor with three levels: N1, N2, N3 of 90, 120 and 150kg of N ha-1, respectively. The shading condition was the sub-factor with two regimes: S1 - no shading and S2 - 30% shading (30% reduction in solar radiation using black netting). The observation parameters included main stem length, number of leaves, and number of primary branches. The physiological indicators (LAI, SPAD, dry mass) were measured at 30, 60, 90, and 120 days after transplanting. Yield and total content of saponins and flavonoids were determined at harvesting time. The results showed that the application of the 30% shading condition combined with increasing nitrogen application doses had positive effects on the growth and yield of Jiaogulan. The highest yield was obtained in the treatment combining the 30% shading condition and N3 nitrogen application level. The total flavonoid and total saponin contents did not significantly differ among the treatments. Thus, in the spring-summer season, a combination of a 30% shading condition and nitrogen application of 150 kg N ha-1 should be applied to produce good growth and high yield as well as ensuring the quality of Jiaogulan.

In-vitro regeneration of soybean is a prerequisite for successful genetic transformation. This study aimed to investigate the culturability of three soybean cultivars for in-vitro regeneration, focusing on genotypes, media, explant types, and plant growth regulators. Shoot tips, cotyledons, and hypocotyl segments were excised from 7-day-old in-vitro seedlings as explants for subsequent in-vitro regeneration. All cultivars exhibited good callus formation from all types of explants, with shoot tips and cotyledons being more suitable. Calluses were induced on Gamborg B5 or Murashige and Skoog (MS) media using various concentrations of 6-benzyladenine (BA) and thidiazuron (TDZ) or 2,4-dichlorophenoxyacetic acid (2,4D). The combination of BA and TDZ or BA and 2,4D exerted an inhibitory effect on shoot and root induction. Media supplemented with BA produced calluses at a rate of 100%. Appropriate BA concentrations for shoot induction for ĐT35 and VNUAĐ2 were 1.0-2.0 mg L-1, and 2.0-3.0 mg L-1, respectively. MS + 2 mg L-1 BA for shoot tip explants and MS + 3.0 mg L-1 BA for cotyledon explants were appropriate to induce calluses and shoots. As BA concentrations increased, the root induction rate gradually decreased considerably. For both ĐT35 and VNUAĐ2, MS + 2.0 mg L-1 BA + 0.5 or 1.0 mg L-1 αNAA could be used to multiply calluses. Although shoots induced from calluses of ĐT35 were observed on MS + 1.5 or 2.0 mg L-1 BA + 1 mg L-1 αNAA, no shoots were observed for VNUAĐ2.

The score function is used to compare intutionistic fuzzy numbers. In this paper, a novel score function of intuitionistic fuzzy sets (IFSs) is investigated. The novel score function was constructed by combining the polynomial and exponential functions working on the degree of membership and degree of non-membership of intuitionistic fuzzy sets. Then, the newly obtained measure overcomes the limitations of some existing score functions. Next, we applied the new measure to construct a method to deal with a multi-criteria decision-making (MCDM) problem. Finally, this MCDM model was used to assess the quality of software projects. The results showed that the new measure was well done and better than other score functions in some cases. This demonstrate the effectiveness of the newly proposed method.

This study explored the factors affecting members’ satisfaction with the quality of support activities of cooperatives using data collected from 301 members of horticultural cooperatives in Son La province. The study applied the SEVERQUAL concept and cooperative principles to develop the research model. Exploratory factor analysis (EFA) and the regression model were used for data analyses. Members’ satisfaction with the quality of the support activities of the cooperatives was specifically evaluated by measuring members’ satisfaction with collective input purchasing; collective marketing; self-help activities; support activities for directly receiving government support; and capacity-building activities. It was found that “Responsiveness” was the prominent factor, followed by the “Assurance and Reliability”, “Empathy”, “Competency of cooperative managers”, and “Tangibles” factors, which were found to positively affect the members’ satisfaction with the quality of the support activities of the cooperatives. To enhance the members’ satisfaction with the quality of the support activities of the cooperatives, the responsiveness of cooperative managers to market risks; social relationships among members; members’ awareness about voluntary participation opportunities in the cooperatives; competency of managers in management and negotiation; internal control systems of the cooperatives; involvement of members in the decision-making process; investment of equipment with internet connections; and the number of members should be improved.

Creating credit is the main income-generating activity for banks. However, granting credit always comes with risks. Credit risk is the risk of losing part or all of a debt due to failure to pay on time or default. Credit risk is considered the most important risk affecting banking performance. Therefore, this study measured the effect of credit risk on the financial performance of Vietnamese commercial banks. The research sample was made up of 30 commercial banks in Vietnam during the period from 2017 to 2022. There were a total of 180 observations in the balanced data panel. To control for unobserved individual effects, this study used a fixed effects model (FEM) with adjusted standard errors. Return on equity (ROE), return on asset (ROA), and net interest margin (NIM) were the indicators for bank financial performance. The non-performing loan (NPL) rate variable represented credit risk. The control variables were cost to income ratio (CIR), equity to asset (ETA), total loans to total assets (LTA), GDP growth (GDP), and Covid. The research results showed that credit risk had a negative and statistically significant effect on the banks' financial performance. This can be explained by the increase in the NPL ratio, causing banks to increase provisions for loan losses, thereby reducing profits. Reduced profits were also because of poor risk management, information asymmetry, and moral hazards. The study also provided a number of solutions and recommendations to improve bank financial performance.

The conventional agricultural sector is threatened by several factors that cause unsustainable development and serious environmental damage. Circular agriculture is regarded as an essential means and is being adopted globally by many countries. Through a narrative literature review, this article aims to discuss the concepts, theories, and practices of circular agriculture, and to draw recommendations for successful implementation. The findings reveal that circular agriculture focuses on promoting resource circularity in the agro-food value chain, minimizing external inputs, reducing resource requirements, regenerating bio-ecosystems, and reducing environmental impacts to meet increasing food demands and improve producers' livelihoods. Circular agriculture differs from conventional agriculture in terms of its principles, levels of circularity, evaluation criteria, and practices. Circular agriculture practices have been adopted globally due to their economic, social, and environmental benefits. However, circular agriculture still encounters obstacles to widespread adoption, such as vested interests and existing policies. Thus, a comprehensive strategy for circular agriculture development should include rethinking and repurposing the sector development strategy; enhancing changes in producer and consumer awareness and behaviors regarding circular agriculture and organic products; increasing investments in circular technology research and development; providing more incentives for producers to access credit and extension services, produce organic products, and to reuse and recycle agricultural resources; and strengthen farmers' organizations to adopt circular farming technologies.