Vol. 5 No. 4 (2022): Vietnam Journal of Agricultural Sciences

A data set of 140 selected rice varieties from regional registration testing in the Mekong delta with four rice registration groups was studied for quality properties and correlations between each quality parameter and comprehensive taste quality in this paper. Differences in rice quality among the four registration groups and three taste categories were identified. (1) The three maturity groups of A0, A1, and A2 could be divided into fairly good and medium taste categories only whereas the aromatic group could be divided into three taste categories. (2) In the A0, A1, and A2 groups, the amylose content values of the fairly good taste category were lower than those of the medium taste category in the three groups, by 5.91%, 4.38%, and 6.38%, respectively (P <0.05). However, the gel consistency values of the fairly good taste category were higher than those of the medium one, by 25.79mm, 16.53mm, and 26.66mm, respectively. (3) In the aromatic group, the hulling percentage and milling percentage of the good taste category were lower than that of the medium one, respectively. The grain length, length/width ratio, smell, and taste of the high-taste quality category rice were higher than those of the medium taste category rice, however, the amylose content was non-significantly different among the three taste quality categories (P <0.05). (4) The smell and tenderness were found to be highly positively correlated with the comprehensive taste quality, but the amylose content was highly negatively correlated with the comprehensive taste quality in all groups (P <0.01).

Nutrient acquisition at the larval stage has significant impacts on the development, body weight, and fecundity of fruit flies. In this study, we examined the effects of diet composition on the life-history traits of the oriental fruit fly Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). We reared the flies on four larval diets, namely three artificial diets, which had the main ingredients of sugar, brewer’s yeast, and preservatives; and one fruit-based diet, which had the main contents of ground guava, brewer’s yeast, and preservatives. The three artificial diets had varied yeast-to-sugar ratios (Y:S) of 5:1 in the protein-rich diet, 1.67:1 in the standard diet, and 1:3 in the sugar-rich diet. Differences in development time, pupal weight, adult weight, and fecundity of B. dorsalis were investigated. It was found that the development times of fruit flies on the protein-rich and fruit-based diets were shorter than those on the sugar-rich and standard diets. Pupae and adults in the fruit-based and standard diets were heavier than those from the protein-rich and sugar-rich diets. There was a strong effect of diet on the per-day fecundity whereby the flies in the fruit-based diet had the highest per-day fecundity, while the lowest per-day fecundity was in the sugar-rich diet. The per-day fecundity of the fruit flies on the standard and sugar-rich diets increased gradually from day 1 to day 15, while it decreased in the protein-rich and fruit-based diets.

This study aimed to estimate the allelic and genotypic frequencies of single nucleotide polymorphisms (SNPs) of MC4R (melanocortin-4-receptor gene) and PIT1 (pituitary specific transcription factor-1) genes, and their additive dominance genetic effects on production and carcass traits in Duroc pigs. A total of 2170 tail tissue samples (1728 gilts and 442 male pigs) were collected from Dabaco Nucleus Breeding Pig Company, Bac Ninh province, Vietnam from January 2017 to June 2020. Polymorphisms in the MC4R and PIT1 genes were detected using the PCR-RFLP method. For MC4R, the frequencies of alleles A and G were 0.430 and 0.570, respectively. For PIT1, the frequencies of alleles A and B were 0.460 and 0.540, respectively. The genotype frequency distribution of the MC4R gene was in Hardy-Weinberg equilibrium (P = 0.375), but the genotype frequency distribution of PIT1 (P <0.001) was not. The MC4R and PIT1 polymorphisms were significantly associated with final body weight and average daily gain (P <0.001). Significant additive effects were also found (P <0.05) for the two traits. The selection of individuals with the MC4R genotype AA and PIT1 genotype AA could improve final body weight and average daily gain in Duroc pigs.

This study aimed to quantify the phenolic contents and the antioxidant capacities of leaf extract powders from three Myrtaceae plants, namely Cleistocalyx operculatus (Vietnamese name: Vối), Psidium guajava (Ổi), and Rhodomyrtus tomentosa (Sim), investigate their inhibitive activities on the growth of bacteria isolated from spoiled shrimps, and evaluate their values as preservative agents in the cold storage of Pacific whiteleg shrimps (Penaeus vannamei). The extract leaf powders from R. tomentosa, C. operculatus, and P. guajava had high phenolic contents of 281.25, 282.36, and 349.51 mg gallic acid equivalent/g leaf extract, respectively. Among the three plants, the extract powders of R. tomentosa and P. guajava leaves had the highest antioxidant capacities (about 4 mmol Trolox equivalent (TE)/g) followed by the one of C. operculatus (2.85 mmol TE/g). These three extract powders showed significant antibacterial activities against the seven bacteria isolated from cold-stored spoiled whiteleg shrimps with the inhibition zones ranging from 0.33 to 19.67mm depending on the extract concentration. Among the three leaf extracts, the one from P. guajava leaves showed the highest inhibitive activity. Aeromonas sp2 was the most sensible to Myrtaceae leaf extracts while Aeromonas sp4 was the least affected strain. All the extracts showed high inhibitive activities against melanosis, volatile nitrogen-containing compounds formation, lipid oxidation, and microbial growth in stored shrimps, thereby prolonging the shelf-life of the shrimps. The results suggested the potential application of these three Myrtaceae plants as sources of antioxidant and antimicrobial agents in the cold storage of shrimps.

Small and medium enterprises (SMEs), which make up over 90% of the total number of enterprises in Vietnam, play important roles in economic development not only in Hanoi but also in the whole country. As an effective tool in business management, accounting supplies important information for making decisions. Recently, information technology in business, especially in accounting work or e-accounting, has increased, and along with many advantages in terms of job productivity, has also been considered as the source of changing the roles of accountants in business. In order to show evidence of these changes as being the background for issuing solutions to improve information technology applications in accounting areas of enterprises, this study conducted a survey of 186 small and medium-sized enterprises in Hanoi. The research results showed that the lack of knowledge of current accounting staff is one of the two biggest obstacles to improving the application of information technology or developing e-accounting in accounting areas of small and medium-sized enterprises. Almost all the enterprises accepted the positive features of information technology for accounting work, however they still strongly considered the dynamics as well as the satisfaction of specific information technology products in their accounting work, especially in dealing with new business transactions.

Intensive aquaculture on a household-scale in Vietnam’s Mekong Delta region often decreases the quality of the water. The consequences are a negative effect on the yield of Pangasius catfish, which in turn reduces the income generation potential. Water quality management has become an important consideration, not only for sustaining livelihoods from household-scale aquaculture but also for mitigating the impacts on the surrounding water bodies. The purposes of this paper are to identify strategies for improving water quality management in households practicing aquaculture and to understand the role gender plays in water management in the Mekong Delta. The effectiveness of existing household approaches to water quality management was found through analyzing data gathered through interviews. The primary data consisted of interviews with 32 operators of different household-scale aquaculture systems. It was found that in 46% of these households, water quality had declined over the last three years. Several causes were identified including the accumulation of chemicals and antibiotic residues, excessive stocking rates, and a lack of a water treatment system. Several strategies to better manage water quality in these ponds were identified including changing the clean water more frequently, removing sediment after each harvest, planting trees around the ponds, and applying lime to the base of the pond, or using potassium permanganate for disinfection before use. Although many water quality management approaches were in use by households, more than 90% of these activities were implemented by men. 

This research focused on various aspects of the constraints that farmers experience when producing vegetables in the northwest region of Bangladesh. The goal was to describe selected characteristics of vegetable producers in the research region and to investigate the relationship of these characteristics with the constraints they experience. Data were gathered at random from vegetable producers from several places in Chapainawabganj by a properly structured interview schedule. The findings revealed that in terms of overall constraints, most of the farmers (90.5%) encountered medium constraints in vegetable cultivation. Based on the Constraint Facing Index (CFI), the input constraints had the greatest impact on the production of vegetables. The high amount of land rent was ranked first among the input constraints. The lack of suitable cold storage systems held the first position in the case of technical constraints, and the high price fluctuations of vegetables scored the highest among the constraints in the marketing of vegetables. The technical constraints also had a great impact on the production of vegetables in the study area. High land rent, a lack of suitable cold storage, and the high cost of cold storage each scored above 100 out of a total score of 126 according to the CFI index.