Hue University Journal of Science: Agriculture and Rural Development

Testing of some new colored rice lines in Binh Dinh province

Nguyen Hoa Han — 2025-03-13

This study utilized five lines of colored rice and the white rice variety, ANS1, as a control. The experiment was conducted during the Winter-Spring season of 2023–2024 in An Tin commune, Hoai An district, Binh Dinh province. The experimental design was arranged in a completely randomized block format with three replications. The evaluation indicators were implemented according to TCVN 13381-1:2023, including growth and development characteristics, morphological, resistance to pests and diseases, yield and rice quality. The colored rice lines in the experiment had short-day growth duration, ranging from 104 to 108 days; Plant height varied from 96.1 to 109.3 cm; Mostly showed light infection by pests and diseases (score 0-1). Based on the research results, we selected two lines, namely BĐ.1 and BĐ.4, which demostrated better yield potential and quality compared to the control variety, ANS1, in which its actual yields were 70.28 and 68.43 quintals/ha, respectively; Protein contents were 7.96% and 7.88%; Anthocyanin contents were 24.14 mg/100g and 34.29 mg/100g, respectively. The experiments should be continued in the Summer-Fall crop to further assess the adaptability of the new colored rice lines under local cultivation conditions.

Assessment of land use/land cover changes in Hue City during the period 2012-2022

Ho Nhat Linh — 2025-03-13

This study evaluates the changes in land use/land cover in Hue City from 2012 to 2022 by creating three land use/land cover maps for the years 2012, 2017, and 2022 using the Maximum Likelihood Classifier (MLC) method with Landsat 7, 8, and 9 images including five types of land cover: bare land, transportation, water, agricultural, and built-up areas. The Kappa coefficient of the maps, which exceeds 0.9, indicates a reliable level of confidence; however, there are still errors present in the interpretation of Landsat images with a resolution of 30 30m. The results of the study indicate that the expansion of urban space has significantly increased the agricultural land cover, as well as the area of built-up and transportation land, which rose dramatically from 3,902.38 hectares to 7,473.70 hectares. The research shows that after the expansion of the Hue City, the area with the highest building density has tended to develop towards the East-Southeast, due to the incorporation of densely built districts such as Thuan An Ward and Phu Dương Commune. The study has revealed significant fluctuations in land use cover in Hue city during the period from 2012 to 2022, contributing to the understanding of urban development trends and changes in land use structure following the administrative boundary expansion.

Effects of planting density and pruning on growth, development and yield of polyhouse grown Maya baby cucumber

Tran Thi Tuyet Hong — 2025-03-13

Baby cucumber (Cucumis sp.) is a vegetable commonly eaten in Vietnamese daily meals. Planting density and pruning are factors that influence the growth, development, and yield of Maya baby cucumbers. This study was conducted from June to August 2023 in Cu Chi District, Ho Chi Minh City, with the aim of determining the most suitable planting density and pruning method for the growth, development, and yield of baby cucumber in a polyhouse. The two-factor experiment was arranged in a complete randomized design with three planting density levels: 3.174 (70 45 cm), 2.857 (70 50 cm), and 2.597 plants/1.000 m² (70 55 cm) and two pruning methods: no pruning and pruning all level 2 branches. The results showed that the interaction between these two factors significantly affected the yield of baby cucumbers. The highest fruit productivity was observed when a planting density of 2.597 plants/1.000 m² (70 55 cm) was combined with pruning of all level 2 branches. This result can be applied to growing baby cucumbers in polyhouses in Ho Chi Minh city and other areas with similar climates.

Investigation of Cyanobacterium Planktothrix spiroides (Wang & Li 2013) Biomass Recovery Method and Evaluation of IAA Biosynthesis Ability

Nguyen Thi Thu Lien — 2025-03-13

This study investigates methods for recovering the cyanobacterium Planktothrix spiroides (PHO) biomass, a potential source for biofertilizer production due to its ability to biosynthesize IAA. Various flocculation methods were tested, including pH adjustment and the use of FeCl₃ and chitosan. The results indicate that pH 8 is the optimal condition for flocculating PHO biomass, achieving an efficiency of 83% after 1 hour. Using FeCl₃ at a concentration of 200 mg/L resulted in a 95% biomass recovery within 15 minutes. The use of chitosan—a natural and environmentally friendly flocculant—also yielded high efficiency, with 93.33% of biomass recovered after 10 minutes at a stirring speed of 40 rpm and a chitosan concentration of 25 mg/L. The chitosan-based method not only ensures high flocculation efficiency but also minimizes the loss of IAA content in the culture medium as well as in the PHO biomass. The loss rate is estimated to be less than 1% in the culture medium and 6% in the biomass.

Effects of growth regulator naa and substrate on rooting of diamond frost trees (euphorbia hypericifolia l.) cuttings in the nursery stage in Ho Chi Minh city

Huynh Thi Thu Ha — 2025-03-13

The Diamond Frost plant (Euphorbia hypericifolia L.,1753) is classified as a herbaceous species characterized by its compact form and white inflorescences, making it highly suitable for cultivation in pots for ornamental applications on balconies. This study aimed to evaluate the effects of the growth regulator naphthaleneacetic acid (NAA) and various substrate compositions on the rooting of Diamond Frost cuttings during the nursery phase. A two-factor experiment was conducted using a completely randomized design (CRD) with three replications, incorporating five levels of NAA concentrations and four distinct substrate compositions. The results identified the optimal NAA and substrate combinations for propagating Diamond Frost seedlings through cuttings in a polyhouse under the climatic conditions of Ho Chi Minh City, with combinations included NAA treatments at concentrations of 1,500 ppm, 3,000 ppm, and 4,500 ppm, paired with substrates consisting of 70% coconut fiber, 20% vermicompost, and 10% rice husk ash; 30% coconut fiber, 30% loamy soil, 30% vermicompost, and 10% rice husk ash; or 35% coconut fiber, 35% loamy soil, 20% vermicompost, and 10% rice husk ash. The findings indicated that the optimal protocol for the development of Diamond Frost cuttings involved treating cuttings with 1,500 ppm NAA and using a substrate mix of 35% coconut fiber, 35% loamy soil, 20% vermicompost, and 10% rice husk ash. This combination achieved a rooting rate of 84.67%, with an average of 11.4 roots per cutting, an average root length of 6.2 cm, and a transplant success rate of 82.0%. The profit generated was 4,205 VND per pot.

Effect Of Low Frequency Ultrasound (20 Khz) On The Density And Virulence Of Vibrio Alginolyticus Causing Haemohagic Disease In Red Drum (Sciaenops Ocellatus)

Nguyen Thi Xuan Hong — 2025-03-13

Haemorrhagic disease caused by Vibrio alginolyticus is one of the major challenges in marine fish farming, particularly in the intensive cage farming of red drum (Sciaenops ocellatus). Aim of this study was to evaluate the impact of low-frequency ultrasound (20 kHz) on the virulence of V. alginolyticus in the context of haemorrhagic disease in red drum. Experimental results showed that exposure to low-frequency ultrasound in bacterial suspensions for 10, 20, and 30 minutes reduced bacterial density and decreased the activity of several enzymes, including lipase, phospholipase, caseinase, and haemolysin. Furthermore, experimental infection of red drum with V. alginolyticus treated with low-frequency ultrasound for 10, or 20 minutes resulted in a lower mortality rate compared to the control group, where bacteria were not treated with ultrasound.

Linking the IPCC AR4 & AR5 Frameworks in Assessing Vulnerability and Risks of Climate Change: A Bibliometric Analysis in Southeast Asia

Hoang Dung Ha — 2025-03-13

Climate change (CC) is a significant challenge to sustainable development, particularly in Southeast Asia (SEA), a region severely affected by extreme climatic events and rising sea levels. The Intergovernmental Panel on Climate Change (IPCC) introduced two key theoretical frameworks in AR4 and AR5 to assess vulnerability and risk in the context of global CC. AR4 focuses on endogenous factors such as exposure, sensitivity, and adaptive capacity, while AR5 expands the concept of risk by incorporating the hazard component. This study employs bibliometric analysis to evaluate the interconnection of research on vulnerability and risk in SEA based on the AR4 and AR5 frameworks, using data from the Scopus database. The results indicate a sharp increase in research output in this region since 2015, particularly after the release of AR5. Leading countries, including Singapore, Vietnam, and the Philippines, play central roles in international collaboration within SEA. The study highlights the importance of international and regional cooperation in addressing CC while providing a scientific basis for policies and strategies toward sustainable development in SEA.

Developing equation to estimate natural forest carbon based on using Sentinel-2 imagery: Case study in Da Nang city

Nguyen Huu Tam — 2025-03-13

Using remote sensing images and forest inventory data to estimate forest biomass basing on parameters and image indices that has been conducted for more than two decades on the World. In which, the Sentinel 2 image has quite high resolution and suitable for analyzing the relationship of forest vegetation reflectance indices with forest biomass, furthermore the Sentinel 2 images are free of charge so it contributes to reducing costs in estimating natural forest carbon stocks. This study was conducted to develop correlation equation between natural forest carbon stocks and normalized difference vegetation index (NDVI) of Sentinel 2 images in Danang city through linear and non-linear models. The study found out that the overall accuracy of the classification map is 96%, with a Kappa coefficient of 0.94. The regression equation TC = 5297,1 NDVI² – 6127,9 NDVI + 1751,8 with R² = 0.8713 and an accuracy of 83.41% was selected for estimating natural forest carbon stocks in Danang city.

Study on biomass and gypenoside production of Gynostemma pentaphyllum via suspenssion cell culture

Dang Ngoc Sang — 2025-03-13

Gynostemma pentaphyllum (Thunb.) Makino can be used for both medicinal and tea and has lipid-lowering properties. It has many beneficial effects such as hypolipidemic, anti-cancer, cardioprotective, hepatoprotective, neuroprotective, anti-diabetic and anti-inflammatory. Its main bioactive components are flavonoids and saponins. In this study, determining a suitable culture medium and testing the bioreactor culture of suspension cells for biomass and gypenoside production were performed. In Erlenmeyer flasks cultivation, the suitable culture medium is basic MS supplemented with 2 mg/L KIN combined with 0.5 mg/L IBA, 3% sucrose with fresh biomass value of 3.693 g/50 mL medium, gypenoside and Rb1 content reached 40.240 mg/g and 0.041 mg/g dry weight after 18 days of culture, respectively. Preliminary cultivation in bioreactor containing 6 L of medium showed that fresh cell biomass reached the highest after 18 days, reaching 45,611 g. Meanwhile, gypenoside and Rb1 content reached the highest on day 16, with values of 40.090 mg/g and 0.038 mg/g dry weight, respectively. The results show that it is possible to grow suspension cell of jiaogulan in bioreactor to produce biomass, providing raw materials for the gypenoside production process.

Genetic diversity assessment of Parashorea stellata Kunz. population in Hue city based on pcr-issr markers

Le Thai Hung — 2025-03-13

Parashorea stellata is naturally distributed in Hue City, is a species of the Dipterocarpaceae family, and has high economic and conservation value. Biological information on P. stellata has been described, but it is still incomplete. This study collected leaf samples from 40 trees in 5 different regions in Hue City to analyze genetic diversity based on PCR-ISSR markers. The results showed that 9/15 ISSR markers were expressed in 100% of the research samples. The genetic diversity of the P. stellata in Hue City is lower at the population level (PPB = 52.3%; Na = 1.519; Ne = 1.313; H = 0.181; I = 0.270) than at the species level (PPB = 100%; Na = 2.000; Ne = 1.5239; h = 0.3404; I = 0.5225). The populations in the sampling areas have lower genetic diversity than the whole province, with the genetic variance coefficient Nei < 0.5 (Gst = 0.2936) and the gene exchange coefficient higher than 1.0 (Nm = 1.2033). The phylogenetic tree divides the P. stellata population into two large groups with genetic distances from 0.79 - 1.0. The results are important scientific data in the work of selecting breeds to build solutions for the conservation and development of P. stellata in Hue City and Central Vietnam.