Vietnam Journal of Agricultural Sciences

Vine tea (Ampelopsis cantoniensis (H&A) Pl.) is a beneficial herbal tea with a high content of the natural antioxidant dihydromyricetin (DHM). Five accessions of vine tea were collected from different locations in Vietnam, viz. VT-CD01 (collected in Sapa), VT-CD02 (Lai Chau - 1), VT-CD03 (Lai Chau - 2), VT-CD04 (Son La), and VT-CD05 (Bac Giang), and were grown in Sapa, Lao Cai, Vietnam from 2017 to 2020 to evaluate their agro-biological characteristics and DHM contents. The leaf color, color of the young petiole, and leaflet shape of these accessions showed similar morphological characteristics to the snake wine vine. VT-CD01, VT-CD02, and VT-CD04 featured purple young leaves, whereas the leaves of VT-CD03 and VT-CD05 were green. VT-CD01 and VT-CD02 showed the best growth with the highest numbers of branches, high yields, and high DHM contents (35.02% in VT-CD01 and 35.25% in VT-CD02). The DHM in VT-CD03 (34.41%) and VT-CD04 (30.86%) also were high, whereas that in VT-CD05 (6.3%) was lower than the requirement of Vietnamese Pharmacopeia V (18%). The accessions VT-CD03, VT-DC04, and especially VT-CD01 and VT-CD02 should be cultivated and are recommended for the treatment of inflammatory-related diseases.

The evaluation of hybrid maize in terms of agro-morphology and genetic variability is crucial for hybrid maize development programs. The main purpose of the study was the evaluation of the performance of various hybrid genotypes in terms of production. The study was conducted at the research field of Prithu Technical College, Lamahi Dang. Twelve maize hybrids with three replications were under study in a randomized complete block design (RCBD) during the spring of 2021. Rampur Hybrid-6 and Rampur Hybrid-10 were the standard checks. Each genotype was cultivated in a plot of 3m x 3m resulting in a net plot area of 385 m2 per block. Analysis of variance showed that all the studied traits were found to be significant except ear length, ear diameter, and the number of kernel rows per ear. Three varieties, RML-98, RML-4, and RL-107, were found to be superior with grain yield values of 11.26, 9.92, and 10.22 tons ha-1, respectively, which were higher than the standard checks Rampur Hybrid-10 (9.24 tons ha-1) and Rampur-Hybrid-6 (8.23 tons ha-1). A positive correlation was found between the number of kernels per row and grain yield. The trait with the highest impact on the grain yield was days to silking. Therefore, these traits are suggested for selection in further breeding improvement programs

This study evaluated the impact of pollution sources on the Ma River Basin in Son La Province, Vietnam, using data from local reports, statistical yearbooks, and scholarly literature. Through spatial analysis and statistical methods, the study mapped the distribution of pollutants across sub-basins in Song Ma district and assessed the pressure of each pollution source on water quality. The findings revealed that livestock raising and domestic activities were the major contributors to water pollution in the cluster 1 of sub-basins, while land-use activities were major threats to the surface water in the cluster 2 of sub-basins. The study recommended implementing centralized wastewater treatment systems in priority areas, promoting sustainable land management practices, and supporting environmentally friendly agricultural and livestock farming methods. These interventions are crucial for achieving sustainable development goals related to clean water and sanitation. The findings underscore the importance of integrated river basin management strategies to mitigate water pollution and ensure the long-term health and sustainability of the Ma River Basin. 

The application of hydro-mechanical transmissions is recently the trend in agricultural vehicles where a continuously variable transmission ratio has advantages. Hydro-mechanical transmissions provide efficient power transfer while maneuverability is still maintained, and therefore, fuel efficiency is enhanced. Nevertheless, the main issue in their employment is a precise control of the hydrostatic unit, whose physical characteristics are highly nonlinear and affected by unknown disturbances. In order to exploit the advantages of the system, the transmission ratio of the hydrostatic unit needs to be controlled properly to maintain the optimal working point of the internal combustion engine (ICE). This article presents numerical comparison results of a proportional-integral (PI) and a neural network (NN) based controller applied to the hydrostatic unit of a hydro-mechanical transmission system, which was designed to be deployed on a self-propelled agricultural vehicle. The controls were established in a discrete-time domain aiming at a practical outcome, where the control algorithm could be implemented on an industrial computer to perform the control tasks.

Despite the rapid increase in online food purchasing practices, particularly through food delivery apps, within developing nations like Vietnam, there remains a dearth of research concerning consumer behavior in this domain. This study aimed to address this gap by investigating the factors influencing consumer intention to use food delivery apps (FDAs) in urban areas of Vietnam. Utilizing a consumer survey in Hanoi, a comprehensive analysis employing multiple linear regression and factor analysis was conducted. The findings indicated that individuals with previous experience using FDAs are more inclined to utilize these platforms for food purchases. Younger demographics exhibited a greater propensity for utilizing food apps for their food-related needs. Importantly, consumers with heightened awareness and trust in FDAs demonstrated a stronger intention to engage with these apps. Additionally, the study underscored the significance of user-friendly, visually appealing, and tailored food app designs in facilitating food purchases through these platforms. Furthermore, it highlighted the influence of food quality and marketing attributes on consumers' intentions to use FDAs. Based on these insights, recommendations were made for online food retailers to enhance market penetration via FDAs. These included designing visually appealing food apps, enhancing food quality, devising effective marketing strategies, providing comprehensive information about FDAs, and fostering consumer trust.

This study investigated the effects of market risk on the financial performance of 47 food and beverage companies listed on the Vietnam Stock Exchange, including the Ho Chi Minh City Stock Exchange (HOSE) and the Hanoi Stock Exchange (HNX), over the period of 2008-2022. Forty-seven companies were selected based on industry classification criteria and relevance in the research period. The return on assets, return on equity, and net profit margin were used to represent the financial performance, and the gearing ratio, book-to-market ratio, and financial leverage as the market risk factors. This research used the OLS model, fixed effect model (FEM), and random effect model (REM) for the panel data. The results showed that the impact of the variables was different in the different models. The book to market ratio and gearing ratio had significant negative influences on the companies’ financial performance while the degree of financial leverage and inflation rate showed positive consequences due to the moderate level of inflation in Vietnam over the period of 2008-2022. Usually, the cash ratio and company size showed a proportional relationship to financial performance, while the ratio of debt to revenue and debt to assets had an inverse relationship, meaning an increase will make the business efficiency decrease. Based on the research results, this study provided some recommendations to improve food and beverage companies’ financial performance, and also provided some information for broader research for non-financial companies listed on the Vietnam Stock Exchange. 

Internal control plays an essential role in improving the efficiency of resources and ensuring the achievement of organizational goals. This study aimed to systematically synthesize articles published in Vietnam and abroad on the topic of “internal control” and “internal control system” in cooperatives during the period of 2012-2023. The conceptual framework of internal control, research methods, and main results of publications were summarized. The findings showed that empirical studies on internal control have frequently been conducted in financial and credit organizations, however, there are limited studies in the cooperative model. The publications focused on three main contents, namely the status and structure of internal control in organizations; the roles and impacts of internal control on performance and corporative governance; and the factors affecting the effectiveness and efficiency of internal control. The COSO framework has been applied by most authors in analyzing the current situation of internal control and internal control systems. The positive impacts of internal control on efficiency (ROA and ROE) and the sustainability of cooperatives were confirmed by the authors. Limitations in human resources, scale, technology, and staff awareness of internal control were considered as barriers to implementation of internal control in organizations.