Vol. 6 No. 1 (2023): Vietnam Journal of Agricultural Sciences

The implementation of breeding programs for indoor vertical farms has been increasing to provide new varieties that have higher nutritional contents and morphological traits fitted to these sustainable production systems. Spinach (Spinacia oleracea L.) is one of the fastest-growing, nutrient-dense leafy vegetables to grow indoors. In Vietnam, market demand for spinach is growing together with the expansion of soilless cultivation technologies such as hydroponics and vertical farming. This research aimed to evaluate the growth parameters, initially screening the relationship between yield and biological traits, of 12 spinach varieties. In addition, this research also aimed to evaluate the lutein, vitamin C, total flavonoid, and carbohydrate contents in different varieties of spinach and their correlations with morphological traits. The research outcomes revealed significant positive correlations between plant weight and leaf area. Three spinach varieties belonging to the smooth leaf type (“AD”, “CH”, and “DT”) were the top three yielding under low light conditions. There were significant differences in the lutein content among varieties. “Red” and “Mikado” were the two highest varieties for lutein content. Vitamin C and total flavonoid contents were statistically similar in the tested varieties, while the carbohydrate content was slightly different among them. This research firstly suggested better suited spinach varieties to be grown in vertical farming conditions, and secondly, provided breeders information on trait identifications to prepare breeding materials for vertical farms

Porcine mucin 4 (MUC4) is a candidate gene for controlling the adhesion of the enterotoxigenic Escherichia coli (ETEC) F4 receptor. Polymorphisms of the MUC4 gene have been used as markers to identify the susceptibility of neonatal diarrhea in piglets for breeding selection. The objective of this study was to evaluate the effects of MUC4 g.243A>G polymorphisms on the production traits of Landrace and Yorkshire pigs in Vietnam. A total of 1,057 Landrace and 1,361 Yorkshire piglets were used to estimate the allelic and genotypic frequencies of the polymorphisms. Body weights at birth, at weaning, at initial fattening (IBW), and at the end of fattening period (FBW), backfat thickness (BFT), and depth of the longissimus dorsi muscle (DLD) were measured and lean meat percentage was estimated. Frequency of the susceptibility allele A to ETEC was higher than the resistance allele G for both breeds based on genotyping piglet tails collected at birth. The AA, AG, and GG genotypes were present in Yorkshire while GG was not found in Landrace. The production traits were not affected (P >0.05) by MUC4 polymorphisms except BFT and DLD (P <0.05). There were interactions between gender and MUC4 genotype (P <0.05) for IBW, FBW, average daily gain, and DLD. These traits of GG males were significantly higher than those of GG females (P <0.05). The results suggest that selecting pigs carrying the GG genotype of MUC4, known as providing resistance to ETEC, do not negatively affect productive performance in Landrace and Yorkshire pigs.

This study examines the effect of brokerage competencies on re-contract intention and customer satisfaction with the elements of ability, knowledge, and attitude as well as understanding the mediation of customer satisfaction on competencies and re-contract intention. The study surveyed a questionnaire with customers in Tan Thoi Dai agent which was a total of 200 samples. The study applied SPSS 20.0 and AMOS 24 to complete all steps of analyzing data in SEM and provide accurate results. Based on the results, the competencies of a broker positively impact the satisfaction of service users through the element of ability, attitude, and knowledge. Moreover, these indicators (ability and attitude) play a significant impact on recontract intention in the direct aspect, in contrast, Knowledge has an insignificant role. Lastly, the level of satisfaction is proved to play a mediating role in the relationship between all the elements of the broker’s capacity and recontract intention due to reducing the coefficient. Interestingly, Customer satisfaction has a full mediation in the correlation of knowledge and recontract intention, while it keeps a partial one in the case of ability and attitude. This study has contributed to the area of developing the efficiency of real estate agents, brokers, and managers. It is necessary to reinforce the competitiveness of real estate agents by raising the rate of revisit intention of old customers. Therefore, to enhance the recontract intention, it is not only paying attention to training for brokers with essential capacities but also the increasing level of satisfaction.

Capital investment is one of the most important financial decisions of a firm, which effects the business survival. This paper investigates the impact of capital investments on firm performance to provide an insight for future capital investment decisions of companies. The study uses unbalance panel data gathered from 62 companies which covered 688 observations of listed food and agriculture sector in Vietnam stock exchange during the period 2009 – 2020. To control for unobserved individual effects, the random effect estimator was employed. Profit margin (PM) is used as a proxy for firm performance, while independent variables are capital investment rate in both short-term and long-term effect, equity to total assets ratio, firm size and tangible to fixed assets ratio. The results indicate that capital investments have statistically significant positive impact on long-term performance of the analyzed enterprises. This outcome is in accordant with many previous studies. Especially in the context of Vietnam listed food and agriculture companies have high level of capital investment, a portion increase in capital investment rate will increase the company profit margin. Other variables also have statistically significant relationship with profit margin, in details, equity ratio and size have positive effect while tangible assets ratio has negative effect on firm performance. Therefore, the research suggest firm managers should choose the appropriate capital investment strategies in long-term perspective, within the consideration of equity ratio, economics of scale and tangible assets investment ratio to get the most efficient performance.

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.