Vol. 19 No. 1 (2021)

Research on physiological and biochemical metabolism in the growth and development of fruit was carried out to determine the time of physiological maturity as the scientific basis for better harvesting and preservation of fruit. Using biochemical analysis methodswere used to determine the content of pigments, reducing sugars, starch, total organic acids, vitamin C, protein and lipids according to the growth and development of longan fruit from until fruit ripening. Results showed that the longan reached a maximum size at 16 weeks of age, at this time the peel of the fruit was light yellow due to the decrease in chlorophyll and increased carotenoid content. Starch content and total organic acid content reached a maximum at 12 weeks of age, then gradually decreased. Reduced sugar and vitamin C content gradually enhanced to 16 weeks of age and then decreased slightly. Protein content decreased gradually from fruit formation until fruit ripening, lipid content increased gradually to 15 weeks of age and then dropped. Through the research process, we determined that the physiological ripe time of longan fruit was 16 weeks old, this was the time when the fruit stopped growing and accumulated most nutrients.

Two experiments were designed to identify the effect of foliar fertilizer application on growth, development and yield of mugwort and Talinum paniculatum. Each experiment was arranged with 4 treatments (control; applying Komix; Dau trau 501; and growmore), the experiments were arranged in RCBD with 3 replications. The results showed that: spraying of foliar fertilizer increased the growth, development and yield of mugwort and T. paniculatumcompared to the control treatment. In particular, spraying of foliar fertilizer Dau trau 501 increases the height, number of leaves, the ability to branch, the net yield in both 2 plants (mugwort and T. paniculatum). At the 2ndcuttings of Mugwort, the leaf area index was the highest (3.9 m2leaf/m2of ground); individual leaves yield (19.3 g/plant) real leaves yield (23.9 quintal/ha), followed by spraying Komix and growmore reached 19.4 quintal/ha. For T. paniculatum, spraying Dau trau 501 obtained the shortens of harvesting time, the number of leaves, branches, leaf area index, the yield was much higher than that in the others in both 2 cutting times. In the first harvesting, the leaf area index reached 1.1 m2of leaves/m2of ground, the individual yield 19.5 g/plant and the real leaves yield reached 25.3 quintals/ha. In terms of aroma and taste, foliar fertilizer application increased the smell but less affected the taste of mugwort and T. paniculatum.

This study was conducted to evaluate the effects of expanded on the growth and yield of perilla plant (Perilla frutescens). The experiments consisted of 5 expanded clay sizes: G1 (1.0cm), G2 (2.0cm), G3 (3.0cm), G4 (4.0cm), and G5 (5.0cm); was arranged in in randomized complete block (RCB) with 3 replications.The results revealed that the small size of expanded clay(2cm) was suitable for the growth of the perilla plants. Specifically, from time of 30 and 150 days after planting, the plant height of perilla was ranged from 34.8-135.9cm, stem diameter ranged from 0.78-1.57cm. The leaves per stem and branches per stem were recorded as 16.2-55.9 and 28.57-74.23, respectively. Of our interest, the dried weights in roots, stems, and leaves were significantly higher than other formulas. The yields increased in the period of 30-120 days after planting, with the total productivity reached to 234.74 g/plant. Taken together, our results could provide a solid foundation for the application of ceramic particles in the cultivation of perilla plants.

The present study was conducted to improve the efficiency of in vitroproduction of bovine embryos. Bovine oocytes were matured either in BO-IVM or TCM199 medium then evaluated the maturation rates by orcein staining. After maturation, bovine oocytes were in vitro fertilized (IVF) in a medium with frozen-thawed sperms at different concentrations (1, 2, or 5 ×106sperms/ml) for 12 hours. The fertilization process was then evaluated at 3, 6 or 12h of oocytes and sperms co-incubation to determine the optimal sperm concentration and co-incubation time. Denuded zygotes were then transferred into SOF medium with or without pre-cultured cumulus cell to evaluate the cleavage rates at day 3 and blastocyst formation rates at day 7. There was no significant difference in the maturation rate of bovine oocytes cultured in BO-IVM or TCM199. Fertilization of bovine oocytes with frozen-thawed sperms at 2 ×106sperms/ml for 6 h significantly improve the fertilization rate and blastocyst formation rate (69.87% and 29.1%). The cleavage rate and blastocyst rate of cattle fertilized oocytes cultured in SOF medium with pre-cultured cumulus cells were higher than those of embryos cultured without cumulus cells (76.34% and 34.16% vs 54.23% and 27,22%, P <0.05). The optimal conditions for in vitro produced cattle embryos can be performed as the maturation of the oocytes with TCM199 medium, fertilization at 2 ×106sperms/ml for 6 hours, then cultured in SOF medium with pre-cultured cumulus cells.

This study was conducted to determine the effects of the ratio of digestible lysine/metabolisable energy (ME) in the diets of pregnant sows on reproductive performance, feed conversion ratio, loss of body weight, and post-weaning time to returned estrus. This study included 2 experiments, one in a closed housing condition in Ba Vi pig farm and one in an opened housing condition in Pho Yen pig farm. In each experiment, 30 pregnant sows (Landrace and Yorkshire crossbred) from 2 to 4 parities were arranged according to a completely randomized design into 30 individual pens with 3 treatments (with the digestible lysine/ME ratios of 1,56; 1,76 và 1,95 g/Mcal), each treatment consisted of 10 animals in 10 pens, 1 sow/pen and each pen was considered a replicate. The results showed that in both opened and closed housing conditions, an increase in the ratio of digestible lysine/ME in pregnant sow diets increased neonatal and weaning piglet weight (per litter and per head), and reduced feed consumption per kg of weaned piglets and weight loss of lactation sows. The appropriate digestible lysine/ME ratio in the diet of pregnant sows was from 1.76 to 1.95 g/Mcal.

The objective of this study was to evaluate the current feeding situation and reproductive performance of Brahman crossbred cows bred with Charolais, Droughtmaster and Red Angus semen at smallholders in Quang Ngai province. A total of 90 households with Brahman crossbred were evaluated for cow feed and feeding situation. In addition, 373 Brahman crossbred cows were used to evaluate the reproductive performance, in which 127 cows were inseminated by Charolais, 120 by Droughtmaster and 116 by Red Angus. The results showed that the dry matter (DM), crude protein (CP) and energy (ME) intake of Brahman crossbred cows were not different (P >0.05) and independent from being bred with Charolais, Droughtmaster or Red Angus. The amount of DM, CP and ME intakenby the pregnant cows was 6.9-7.5; 0.6-0.7kg/day and 14.6-15.5Mcal/day, respectively, and 3-month after calving was 7.5-7.6; 0,7kg/day and 15.5-15.9Mcal/day respectively. The calving interval of Brahman crossbred cows bredwith Charolais, Droughtmaster and Red Angus semenvaried between 394-397 days (P >0.05). Further studies should be done on the growth and performance of the progeny of the crosses between Brahman crossbred cows and Charolais, Droughtmaster and Red Angus bulls.

This study aimed to explore regulations implementation of farmers and to assess sustainable aquaculture in Thua Thien Hue province. Qualitative research was applied through 45 semi-structured interviews, two focus-group discussions and collecting involved secondary information. The gap between regulations and implementation of farmers resulted from habits and the freedom in production, lack of trust on the government, limited awareness, demand for livelihood and limitation in monitoring and controlling, which can negatively affect sustainable aquaculture at the locality.

Research on species composition and distribution of bivalvia in central coastal coral reefs was conducted in 2015-2016, in 6 central coastal areas (Nghi Son, Ky Loi, Son Tra, Ghenh Rang, Tuy An and Vung Ro). The results have identified 50 species, belonging to 16 families, 7 orders in the coastal reef in this area. Four endangered species have been identified in the coastal reef ecoregion (list of the Vietnam Red Book). Sorensen species similarity index in the investigation area ranged from 0.37 to 0.70. The diversity index of Shannon - Wiener ranges from 2.83 (Nghi Son) to 3.31 (Son Tra) ... The results of this study contribute to the diversity of the composition of bivalve mollusks in the reproductive system. Coastal reef status in Vietnam is the basis for planning and protecting this resource against the effects of socio-economic activities in coastal areas.

The study was conducted to evaluate the effects of turmeric powder in the diet on the growth performance, diarrhea rate and some immune parameters of weaned piglets. The study was performed on 60 weaned piglets of Duroc x (Yorkshire x Landrace) hybrid. The animals were divided into 4 completely randomized groups: control group (ĐC) used only the basal diet, no turmeric powder added, and experimental group 1 (TN1) used basal diet added 0.1% turmeric powder (1g turmeric powder/kg food) turmeric powder, experimental group 2 (TN2) used the basal diet supplemented with 0.3% turmeric powder and experiment 3 (TN3) used the basal diet with 0.5% turmeric powder supplementation. After 4 weeks of testing, the results showed that the final body weight of pigs in group TN3 with turmeric powder supplemented at 0.5% was heavier than that in groups TN1 and TN2 using turmeric powder at 1 and 0.3%, respectively. The supplementation of turmeric powder to the diet significantly reduced diarrhea rate of weaned piglets (P <0.05). The study results also showed that turmeric powder in the diet did not affect on feed intake and serum IgA, IgG, Interferon antibody concentration.

Theresearch was carried out to investigate Feline panleukopeniadisease at the Hanoi and its vicinity. The study was conducted on 216 cats. The results showed that 83 out of 216 cats (38.43%)identified with the signs of Feline panleukopeniadisease by the clinical diagnosis method. Twenty-nine out of 83 cats were positive with Feline panleukopeniausing quick test method and PCR method accounting for 34.94%.Twenty-nine out of 216 cats were positive with Feline panleukopenia accounting for 13.42%compared with a total of the investigated cats. The Feline panleukopeniavirus infection rate in cats < 12 months was higher than adult cats (P<0,05). The disease is clinically manifested by severe depression, fever, vomiting, dehydration, and enteritis diarrhea and is often fatal. A marked decrease in circulating white blood cells. The average white blood cell count in cats with FPV was reduced to 1.8 ± 0.09 103/µl.

The use of GPS grid geometrical figure following star-shaped links instead ofusing GPS grid geometrical figure following normal link will be a breakthrough to increase measurement speed, increase maximum performance in instrumentation use. However, this method has not been implemented in cadastral grid construction. In order to confirm that it is possible to use the GPS grid geometrical figure following star-shaped links in the construction of the cadastral grid, the research team has evaluated the coordinate differences of the points of the same name in 4 experimental schemes (PA), in which, schemes PA1, PA2 were done according to the normal link, schemes PA3, PA4 were arranged according to the star-shaped links. The results showed that: The error of point position in the 4 schemes has changed (mpmin = 0.004 ÷ 0.006m; mpmax = 0.011 ÷ 0.017m). The largest point deviation in PA2, PA3 and PA4 compared with PA1: according to the x-axis was 0.019m; on the y-axis it was 0.014m and the actual deviation was 0.019m. The experimental results showed that the GPS grid geometrical figure’s criteria have completely met the quality standards for the cadastral grid according to the current regulations, so the GPS grid geometrical figure following to the star-shaped links cam be applied in the construction of the cadastral control framework.

The study was conducted to evaluate seasonal variation in soil quality in My Phuoc melaleuca forest, Soc Trang province through the indicators of pH, conductivity (EC), total nitrogen (TN), total phosphorus (TP), organic matter (OM), total iron (Fet), aluminum exchange (Al) using multivariate statistics. Cluster Analysis (CA), Principal Component Analysis (PCA) and Discriminant Analysis (DA) were used to assess seasonal variation in soil quality. The findings indicated that soil environment in the study area had very low pH, medium Al, EC and high Fet, low TP, medium OM, and high TN. All soil quality indicators (except EC, Al) tended to increase in the rainy season. CA results showed that 28 locations were divided into 6 groups in dry season and 4 groups in rainy season indicating highly seasonally varied in soil quality. PCA results presented that Fet, Al, OM significantly influenced on soil quality in the dry season, while pH, TN, and TP significant affected on soil quality in the rainy season. DA indicated that EC, OM and TP were the main variables causing the difference in soil quality between the two seasons. The results of the study provided important information serving the management of soil environment quality in My Phuoc Melaleuca Forest Reserve.

The purpose of this studywas to focuson screening native plants capable of absorbing heavy metal chromium (Cr)to treat contaminated soil. By field investigation method combined with a greenhouse experiment to determine growth capacity, critical points, TF and BF coefficient, 48 plant species with their outer morphology specific to heavy metal hyper-accumulator were collected. After examining scientific names, making a checklist of plant species, the results showed that there were 16 orders, 21 families, 37 genera capable of accumulating heavy metals. Among them, 4 plant speciesweresurvived in Cr contaminated soil from 150- 350mg/kg dried soil concluding: (1) Cyperus rotundusL., (2) Cynodon dactylon(L) Pers., (3) Amaranthus spinosusL., (4) Solanum nigrumL. in which Solanum nigrumL. is dominant in terms of both biomass andthe transportas well asbioaccumulation coefficient. Under normal farming conditions and soil contaminated with Cr concentration of 150- 350 mg/kg, Solanum nigrumL.hasgrownwell and attainedthe highest Cr treatment efficiency in contaminated soil from 150- 250 mg/kg dried soil.

The study aimed to determine the impact of these factors on residential land prices in Vinh City and to propose some recommendations when determining residential land prices. Secondary data were collected from functional departments in Vinh city. The primary data were collected through surveys of 181 people related to the establishment and appraisal of residential land prices. The data were analyzed through Cronbach's Alpha coefficients, exploratory factor analysis and linear regression models by software SPSS 20.0 and Amos 24.0. There were 28 factors belonging to 9 groups of factors included in the regression model that had an impact on residential land prices with the impact rate from 4.43% to 17.23%, respectively. When determining residential land prices, it is necessary to pay attention to the impact of the groups of factors on residential land prices such as the relationship between supply and demand of land use rights; plot location; rate of urbanization and urbanization speed in the present and the future etc., to determine the appropriate price of residential land in each stage of the urbanization process and harmonize the interests of the State and land users and organizations related to land use rights in Vinh city, Nghe An province.

The purpose of this research was analysing the factors affecting the students’s learning motivation of the Faculty of Accounting and Bussiness Management, Vietnam National University of Agriculture. This study surveyed 190 students with Cronbach's alpha method, Exploratory Factor Analysis, regression analysis. Results showed that the factors affecting the students's learning motivation were students theselves, friends and societies, and others. Then this research proposed some solutions to promote student’s learning motivation.

This study analyzed the current status of aquacultural cooperatives in Quynh Nhai, Son La, in order to identify obstacles in the development of this cooperative type. Our research approach was made following the performance assessment criteria of Circular 01/2020/TT-BKHDT issuing on February 19, 2020 by the Ministry of Planning effectively from April 1, 2020, to do the survey on 21 aquaculture cooperatives and their 107 cooperative members in Quynh Nhai. The research results showed that: (i) the aquacultural cooperatives have still had difficulties in accessing policies on land (surface area) and credit; (ii) Small and micro scale of capital and assets for production; (iii) A stable development value chain has not yet been formed; (iv) The managers’ competence was still limited for an extensive development or innovation.