Vol. 22 No. 10 (2024)

The research aimed to select varieties and determine the off-season planting date on radish crop in accordance with the advantage of cool climate in highland Van Son commune, Tan Lac district, Hoa Binh province and communes with similar conditions. Therefore, the two-factor experiment was arranged in Spit-plot design with mainplot as: three off-season planting date (March 25, 2023 (off-season 1), April 14, 2023 (off-season 2), May 7, 2023 (off-season 3)), while subplots were three radish varieties as: TN45 radish, Short-leaf radish No. 13 and Song Jeong radish with three replications was conducted. The results showed that the off-season 2  was the most suitable for growth, physiology, yield and quality of radish with the actual yield 33.53 tons ha-1. The Song Jeong radish variety was the most suitable for off-season radish production with the highest in average tuber matter, highest actual yield (32.28 tons ha-1), tuber quality parameters such as fiber and vitamin C content were both the best. Combining the off-season 2 and the Song Jeong variety were most suitable for Van Son highland commune due to growth, physiological, yield and quality higher than other varieties and seasons, with a actual yield of 48.37 tons ha-1.

This study was conducted to assess the influence of different ecological sub-regions on the yield and quality of brown rice from local glutinous rice varieties and newly released Japonica rice varieties. The field experiments was conducted in during 2021 spring and autumn cropping seasons Moc Chau - Son La and Muong Thanh - Dien Bien. The findings revealed that local glutinous rice varieties had greater capacity for dry matter accumulation compared to the new Japonica varieties across all ecological regions. However, the yield of new Japonica variety, Ja35 (6.92-7.35 tons/ha), was significantly higher than that of local indigenous rice varieties (5.55-6.43 tons/ha). The different ecological subregions exterted significant impact on the lipid content in brown rice, but did not notably affect the protein content in brown rice of all rice varieties in all cropping seasons. It was observed that the lipid content in brown rice and rice bran in Dien Bien was higher than that in Son La. In contrast, the oryzanol content in brown rice in Son La was higher than that in Dien Bien for all rice varieties and seasons. The new rice varieties exhibited a higher oryzanol content compared to the indigenous varieties by 0.2-0.3%.

This study was carried out to determine growth curve models for estimating live weight, weight gains and suitable slaughter age for Hac Phong chicken. A total of 100 (53 males and 47 females) birds were raised and and individual live weight data was collected every week from 1 to 20 weeks of age. The data for growth performance was analyzed in R software (version 4.2.2). Seven growth functions, viz. (von Bertalanffy, Janoschek, Gompertz, Logistic, Lopez, Richards, and Weibull), were used to be fitted with the growth data. The results showed that Lopez function was the best model to describe the growth of Hac Phong males and females. The weekly gain (WG) reached the maximum at the 6th week age for both male and female chockens. The maximum of the average weekly gain (AWG) was obtained at the 17.34th week for both of the male and female; 21.72th week of age and the 12.32th week of age for the male and the female, respectively. This suggested the suitable slaughter ages are 17.73 weeks for both of the males and females, with a weights of 1,105g.

The study was conducted to survey the phytoplankton composition and abundance from intensive whilewhite shrimp (Litopenaeus vannamei Boone, 1931) culture in earthen ponds in Cai Nuoc district, Ca Mau province. Phytoplankton samples were collected once every 7 days until the harvest period, with a total of 13 sampling times. The results of this study showed that 77 phytoplankton species were identified that belonged to 4 phyla, Cyanobacteria, Chlorophyta, Bacillariophyta and Dinophyta. Among these diatoms were the dominant communities with 53 species (69%), whereas the remaining phyla contained fewer candidates in a range of 3 to 13 species (4 to 17%). The phytoplankton population ranged from 15 to 31 species throughout the study period, and the abundance of phytoplankton was around 12,080,036 to 181,150,577 ind./l. Bacillariophyta possessed the highest number of species while Chlorophyta was the most abundant group in this study. The green algae and dinoflagellate densities were obtained the highest in Pond 1 compared to those in Pond 2 and Pond 3. The most prevalence of cyanobacteria was found in Pond 3, whereas Diatoms were the most abundant in Pond 2 rather than others. In addition, Chlorella sp. and Nannochloropsis sp. reached the most abundant species in this study with means of 12,083,467 ± 7,260,148 ind./l and 22,581,921 ± 24,220,920 ind./l, respectively.

A study on conditioning of white catfish (Clarias batrachus) broodstocks using 100% trash fish (NT1), 50% trash fish combined with 50% pellets (NT2) and 100% pellets (NT3) was conducted to evaluate the possibility of replacing trash fish by pellet. The experiment was randomly designed with 3 treatments in triplicate. The broodstock was stoked in recirculating aquaculture systems at density of 3.5 kg/500l. After 8 weeks of broodstock conditioning, all treatments showed 100% maturity and good reproduction. The Gonadosomatic Index (GSI) of female was highest in the treatment using 50% trash fish combined with 50% pellet (5.17%) and GSI of male was in the treatment using 100% trash fish (0.21%). Absolute fecundiy ranged from 50,581 to 63,805 (eggs/kg female). The treatment using 100% trash fish had the highest fertilization rate (88.6%), hatching rate (90.6%) and survival rate (97.3%). The results show that using 100% trash fish gives the best broodstock results. The pellet can partially or completely replace trash fish in white catfish broodstock conditioning.

This study was conducted to evaluate the effects of two fermented soybean meals (KĐTLM 1 and KĐTLM 2) on some digestive physiological indices and intestinal morphology of the common carp. Four diets were formulated and denoted as BCD (fish meal diet), KĐTD (soybean meal diet), KĐTLM1D (KĐTLM 1 diet) and KĐTLM2D (KĐTLM 2 diet). Carp fingerlings (body weight 17g) were randomly arranged into 8 tanks (350 liters/tank) with a density of 20 fish/tank (duplication). Fish were fed ad libitum, twice a day for 4 weeks. Results showed that fish fed KĐTD had a significantly lower total plasma cholesterol level, intestinal digestive enzyme activities, bile acid secretion and inferior protein and lipid digestibilities than fish fed BCD (P <0.05). In constrast, these paramethers were similar among fish fed KĐTLM1D, KĐTLM2D and BCD. Intestinal villi length and morphology of fish fed KĐTLM1D and KĐTLM2D were similar to those of fish fed BCD and these two fish groups were markedly better than fish fed KĐTD. The present study indicates that KĐT fermentation improved digestive physiological indices and intestinal morphology of common carp and these improvements may promote growth performance and feed conversion ratio.

The study aimed to assess the effectiveness of deodorizing in livestock barns and chicken manure treatment using the microbial product Vnua-MiosV. Vnua-MiosV was sprayed as a mist to determine its odor mitigation efficiency in the barn area. The results showed that the quality of the air environment after spraying the product was significantly improved (reaching 75.14-92%), in which NH3, H2S, and TVOC concentrations decreased by more than 75%, 90% and 85%, respectively, helping to minimize environmental pollution. Vnua-MiosV product also had the effect of heating up and converting organic matter quickly, helping to shorten composting time. The organic materials formed after composting had high decomposition rate, high available nutritional content and porousity without harmful microorganisms, meeting the standards according to QCVN 01-189:2019/BNNPTNT for organic fertilizers. The exchange P2O5 content was 4.74-5.99% and effective K2O reached 5.36 - 6.86%, increased by 80.53-94.20% compared to the control and higher than Trichoderma - Bacillus product by 25.0-27.1%. However, composting materials need to be further studied in process to produce high quality organic fertilizer for agricultural production.

Platycodon grandiflorus, a medicinal herb, has numerous applications in medicine and Lào Cai province possesesa great potential for developing high-quality cultivation areas for this herb due to its diverse climate and soil conditions. In this study, the authors employed Geographic Information Systems (GIS) combined with Analytic Hierarchy Process (AHP) to evaluate the land suitability for cultivating Platycodon grandiflorus. The aim was to identify and select appropriate locations for cultivating this medicinal plant in Lào Cai province. The evaluation results for the period 2019-2022 indicated a significant increase in cultivation area from 25.0ha to 98.0ha. AHP analysis identified soil type (weight 0.277) and elevation (weight 0.294) as the most critical factors, while rainfall (weight 0.035) was less significant. By combining the weights (Wi) and suitability scores (Xi), the classification results indicated that 32,771 hectares were highly suitable (S1), accounting for 8.91% of the study area, and 44,399 hectares were moderately suitable (S2) for cultivating Platycodon grandiflorus in Lào Cai province.

Shiitake mushroom is a delicious and nutritious mushroom because it contains diverse nutritional components and valuable medicinal active ingredients. Currently, the source of spawn for cutivation of shiitake mushroom in Vietnam is mainly imported from China, Korea or Japan. Collecting and researching native shiitake mushroom genetic resources in Vietnam is so meaningful for the conservation genetic resources. The LeCT mushroom strain is a native shiitake strain which collected in Cat Tien National Park (Vietnam)... The purpose is to find the most suitable conditions for the mycelial growth of shiitake strain LeCT. Mycelial of strain were cultured in different temperature levels, media pH values, carbon sources, mineral salt sources and spawning substrates. The findings show that the most optimal temperature for mycelial growth is 25°C ± 2, the culture medium with pH value of 6 gives the best mycelial growth results. Glucose and MgSO4.7H2O are the best sources of carbon and mineral salts for mycelial growth. Substrate includes 77% boiled rice, 20% corn cob, 2% barley bran and 1% CaCO3 performs the best mycelial growth results.

Amauroderma rugosum contains various biologically active compounds and is considered a traditional medicine in many Asian countries. However, there was little research on this mushroom species in the world and in Vietnam. This study aimed to describe the morphology, analyze the phylogeny, and optimize the conditions for culturing the mycelium and fruiting bodies of the strain Am20 collected in Dong Nai, Vietnam. The results of the morphological study, combined with molecular data on the ITS region sequence showed that the strain Am20 had high similarity to other strains of A. rugosum. The culturing results showed the mycelia of A. rugosum strain Am20 grew well in a PDA medium at pH 6-7 and a temperature of 30°C. Mycellia of this strain could be cultured on the cereal grains such as rice and wheat. The A. rugosum strain Am20 was able to form and develop fruiting bodies on substrates containing sawdust and corn cobs. The most suitable substrate was 89% sawdust, 10% rice bran, and 1% powder CaCO3. The yield reached 21.1 ± 2.45 g/kg dry substrates.

The adoption of the Sustainable Rice Platform (SRP) standard is crucial for maintaining long-term stability and addressing challenges in rice farming in the Mekong Delta. To assess the feasibility of SRP standard adoption, a study was conducted on over 200 farm households who had previously adopted the SRP standard in An Giang and Dong Thap provinces using a semi-structured questionnaire. The level of compliance and application was analyzed based on SRP standard version 2.1 guidelines. The results showed that farmers achieved an average score of 84.7. However, the percentage of farmers achieving sustainable rice cultivation levels remains relatively low, at only 7%. Among the 41 SRP requirements, 16 have not yet met the sustainability level. To improve compliance levels, several solutions have been proposed, such as enhancing farmers' understanding of the SRP standard, providing guidance on farming information records, encouraging the gradual reduction of triple-cropping rice areas, improving farmers’ capabilities in pest management, developing straw collection systems, raising awareness about the harmful effects of pesticides, and simplifying some requirements of the SRP standards.

The study was conducted to analyze factors affecting customer perception of service quality in online shopping in Hanoi City. PLS-SEM model was used to evaluate the factors affecting the perception of 306 customers about service quality with respect to online shopping. The results indicated that 70% of variation in outcome quality was explained by process quality and service recovery quality and 71.5% variation of customer perception of online service quality was explained by process quality, outcome quality, and service recovery quality.

In recent years, cloud computing is growing very strongly in computer science. It plays an important role and position in the process of implementing information technology projects. It has a powerful computing architecture based on the Internet. This technology brings many conveniences to users, but the biggest fear is its safety and security. Security challenges increased with increased cloud usage. That's why many organizations have also implemented projects to provide better security solutions for customers. On the other hand, security experts are also making efforts to research better security solutions. This article presents an overview of the development of cloud computing, its advantages, deployment models and services provided by cloud computing. At the same time, the article summarizes the important challenges in security and privacy in cloud computing, classifies the diverse existing solutions, and compares their strengths and limitations as well as the future research directions.