This study conducted in collaboration with the local community focused on sustainable agricultural tourism development in Dak Lak, Vietnam. Using a qualitative research method, we conducted in-depth interviews with 29 households and agricultural cooperatives, combined with case studies. The results showed that agricultural tourism, a product of our joint efforts, played a significant role in diversifying livelihood sources and contributing to the preservation of ethnic and cultural identity. However, the sustainable development of this sector was hindered by limitations in infrastructure, lack of investment and uneven management capacity. Based on these findings, we propose specific policies and solutions to promote sustainable agricultural tourism development and support rural communities in the context of economic transition.

The study aimed to determine the appropriate amount of potassium for two newly selected sweet corn hybrid combinations of the Department of Genetics and Plant Breeding, Nong Lam University, Ho Chi Minh City. The experiment was conducted in the winter-spring crop of 2023 - 2024 in Thu Duc, Ho Chi Minh City with 4 potassium levels (70, 90, 110, and 130 kg K2O/ha) and 2 combinations of sweet corn hybrids BN191, BN211 and control variety (Golden Cob). The results showed that different rates of potassium affected the yield, quality and resistance to pests and diseases of sweet corn hybrid combinations. The potassium dosage of 130 kg K2O/ha gave the highest fresh ear yield, low pests, and infection rate and highest Brix for the two selected hybrid combinations and the Golden Cob variety.

Solanum procumbens Lour. is a traditional medicinal plant known for its rich glycoalkaloid content. This research aimed to determine the suitable types and application rates of microbial organic fertilizers to enhance yield and glycoalkaloid content in Solanum procumbens Lour. A two-factor experiment was conducted using a Split-Plot Design (SPD) with three replications. The main plots included four types of microbial organic fertilizers (HD301, HD302, Komix-BL2, and HCMK7), while the sub-plots involved three application rates (2, 4, and 6 tonnes/ha per crop). Various parameters were measured, including fresh and dry biomass per plant, fresh and dry yield per ha, glycoalkaloid content, and glycoalkaloid yield across two cropping cycles. The results indicated that applying HCMK7 at a rate of 6 tonnes/ha per crop produced the highest outcomes: in the initial crop, a fresh weight of 255.2 g and dry weight of 111.1 g per plant, fresh yield of 15.77 tonnes/ha, dry yield of 6.99 tonnes/ha, glycoalkaloid content of 0.70%, and glycoalkaloid yield of 48.97 kg/ha. In the ratoon crop, the same application rate yielded a fresh weight of 282.5 g and dry weight of 134.6 g/plant, fresh yield of 17.62 tonnes/ha, dry yield of 9.21 tonnes/ha, glycoalkaloid content of 0.76%, and glycoalkaloid yield of 70.39 kg/ha. The highest average glycoalkaloid content (0.73%) and total glycoalkaloid yield (119.36 kg/ha) across both crops were also recorded at this application rate.

Identifying suitable plant growth regulators for the rooting stage and substrate mixing ratio for seedlings in the nursery remains a significant challenge, particularly in relation to Mai vang. This plant existed in culture and tradition for a long time and was considered a symbol of the traditional Tet. The experiments were conducted on Mai vang HD01 line, which was selected from Huu Duc Mai garden in Binh Loi apricot village, known for its exceptional characteristics. The objective of this study was to determine the optimal Indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) concentrations appropriate for root formation from shoot samples in in vitro condition and the optimal substrate mixing ratio appropriate for the growth of Mai vang HD01 line during the nursery stage. The study including two experiments were arranged in completely randomized design with one-factor and two-factor. For rooting induction, the culture medium supplemented with concentrations of IBA combined with concentrations of NAA was used, while to grow, Mai vang HD01 plants were planted in a substrate of coconut fiber, sand, rice husk ash, and vermicompost with different mixing ratios. The results showed that Mai vang HD01 shoots were cultured on Murashige and Skoog medium supplemented with 0.5 mg/L IBA combined with 2 mg/L NAA suitable for rooting and creating complete plants. The number of roots, root length, plant height and number of leaves were 6.9 roots; 3.5 cm; 2.3 cm and 5.9 leaves, respectively on day 60. Mai vang HD01 plants in the nursery stage were suitable for planting on a substrate with a mixing ratio of 1 coconut fiber:1 sand:1 rice husk ash:1 vermicompost with a 100% survival rate. They grew quickly to a height of 5.1 cm which was higher than that of plants planted on other substrate mix ratios on day 40.

This study was conducted to investigate the effects of the probiotic (Bacillus Liq-Vtech)-supplemented diets on growth performance, intestinal microbe, morphology of the intestine, and resistance to Edwarsiella ictaluri infection in striped catfish (Pangasianodon hypophthalmus). A total of 800 healthy striped catfish (12 ± 2 g) were randomly divided into four experimental groups with four replicates each, and were fed diets supplemented with different levels of Bacillus Liq-Vtech (T1: 0 cfu/g; T2: 0.5 × 106 cfu/g; T3: 1.0 × 106 cfu/g; and T4: 1.5 × 106 cfu/g) for 8 weeks. At the end of the trial, a challenge test with Edwardsiella ictaluri was conducted for 2 weeks. The results showed no statistically significant improvement in the growth performance and survival rate of fish with Bacillus LiqVtech supplementation (P > 0.05). However, there was a tendency for the improved growth performance in treatments supplemented with Bacillus Liq-Vtech. Additionally, the density of Bacillus spp. increased in the intestinal tract of fish fed probiotic-supplemented diets compared with the control. All probiotic treatments exhibited positive effects for different histomorphological features of the intestine. Mucus secreting goblet cells and villi increased in probiotic-supplemented groups. Mortality rates in treatments supplemented with Bacillus Liq-Vtech were lower than those of the control. These results suggested that the Bacillus Liq-Vtech supplementation in diets has the potential to improve growth performance, increase beneficial bacteria in the intestinal tract of the fish, and reduce the mortality of striped catfish after being challenged with Edwardsiella ictaluri.

Maternal-derived antibody (MDA) is the priority protection against environmental Infectious Bursal Disease Virus (IBDV) in the first weeks. The passive immunity decreases, but the active immunity is not enough to protect chicks, so shortening the high-risk period is crucial to IBD control. The objective of this study was to evaluate the immunity gap between 2 vaccination programs against infectious bursal disease (IBD) in Luong Phuong chickens. A total of 34,600 chicks were administered by subcutaneous injection of IBD vaccine at 0.1 mL/dose at the hatchery. At 12 days old, 18,000 chicks were vaccinated with the M.B strain vaccine and 16,600 chicks were vaccinated with the 228E strain vaccine by drinking water. The IBD and Newcastle disease (ND) antibody evaluations were based on the Enzyme-linked immunosorbent assay (ELISA) technique. Parameters were recorded until slaughter including body weight, average daily gain, feed conversion rate, and mortality. The IBD MDA at 1 day old was medium and uniform (3809 and 45.3%), which could protect against IBD virus from 1 to 2 weeks old. At 28 days old, the IBD antibody titer of the MB vaccine was higher than that of the 228E vaccine, various proportions of samples in the M.B group exceeding 1,000 titers (40% vs. 0%), and it was a statistically significant difference (1,133 vs. 161) (P < 0.01). Besides, the M.B vaccine created a faster and stronger immune response than the 228E vaccine, shortening the immune gap and protecting chicks earlier. The humoral immune response to the ND vaccine was good, with no difference between 2 groups, which proved that the M.B virus did not cause immunosuppression. The production parameters of chickens between the 2 groups were the same. In summary, the M.B vaccine made a short immune gap and did not cause immunodeficiency in chickens.

The objective of this study was to evaluate effects of dietary supplementation of shrimp head and shell by-products on growth performance and incidence of diarhea in fattening pigs from August 2023 to October 2023 at the pig farm in Thoai Son district, An Giang province. A total of 90 crossbred pigs [(Duroc x Pietrain) x (Landrace x Yorkshire); 96 days old] were assigned to 1 of 3 treatments with 5 replicate pens of 6 pigs each according to sex, litter origin, and weight in a randomized complete block design (RCBD). The 3 dietary treatments included (1) Basal diet (control), (2) Basal diet + 3 g/kg shrimp hydrolysate powder (SH) and (3) Basal diet + 10 g/kg shrimp heads and shells meal (SM). The results showed that there were no significant differences in the average body weight (BW) and average daily gain (ADG) among the 3 treatments (P > 0.05). Similarly, pigs fed the SH diet (2.99) and SM diet had the same feed conversion ratio (FCR) of pigs (P = 0.767) as those fed the control diet (3.04) during the whole period from 96 to 164 days of age. Furthermore, no significant differences (P > 0.05) were found in the average daily feed intake (ADFI) and the diarrhea incidence among the 3 treatments. Briefly, the results in the current study suggest that dietary supplementation of shrimp head and shell by-products (shrimp hydrolysate powder, or shrimp heads and shell meal) seem to have no positive effects on growth productivity (BW, ADG, ADFI and FCR) and incidence of diarrhea in fattening pigs during 96 - 164 days of age.

Salmonella can carry multiple antibiotic-resistant and metalresistant genes and transmit these genes among strains worldwide. This study examined seventy-five Salmonella isolates from small-scale chicken farms (chicken feces, bedding, feed, wild animals) in Vinh Long province for the presence and relation of antibiotic and metal-resistance genes in these strains. The single PCR method was applied to detect seven antibiotic-resistance genes (blaampC, blaTEM, dfrA1, tetA, strA, sul2, mcr1) and four metal-resistance genes (pcoR, czcD, cnrA, silE). The results indicated that those Salmonella isolates harbored several patterns of antibiotic-resistance genes. Genes blaampC and tetA were the most prevalent (48.00%), while genes mcr1 and dfrA were the most minor (1.33%). Of those Salmonella isolates, 92.00% harbored one to five antibiotic-resistance genes, and the blaampC + strA pattern was frequently obtained (12.00%). Moreover, 30.67% of Salmonella isolates showed multidrug resistance to three or four antibiotic categories. Among metal-resistance genes, gene pcoR encoding for copper resistance was the most predominant (53.33%), and gene cnrA encoding for cobalt-nickel resistance was the lowest (5.33%). There were diverse patterns of metalresistance genes, and one Salmonella isolate carried four examined genes (1.33%). Furthermore, these Salmonella isolates had several combined patterns of metal-resistance and antibiotic-resistance genes. Among them, pcoR, czcD, and silE genes had a significant coefficient relation to the examined antibiotic-resistance genes. It indicated the correlation between metal resistance and antibiotic resistance genes and revealed the potential risk of increasing antibiotic resistance in Salmonella isolates in chicken farms in Vinh Long province.

This study aimed to evaluate the efficacy of estradiol on the survival rate, sex reversal ratio, and growth performance of climbing perch (Anabas testudineus) using the immersion method. A completely randomized design was applied, involving three estradiol (E2) treatment groups at concentrations of 1.0 mg/L (1E2), 1.5 mg/L (1.5E2), and 2 mg/L (2E2), along with a control group triplications. Seven-day-old fingerlings were exposed to the E2 solution for 2 h before being transferred to nurseries in hapas placed in earthen ponds at a density of 200 fish/m² for 60 days. After the hormone treatment and 60 days of rearing, the highest survival rate was observed in the control group (86.7%). The female ratios in the 17β- stradiol (E2) treatments ranged from 72.0% to 90.0%, which were significantly higher than the ratio of the control group (55.6%) (P < 0.05). The 2E2 treatment demonstrated the highest female percentage, which was statistically greater than that observed in the 1E2 and 1.5E2 treatments (P < 0.05). The mean weight and length of fish in the E2 treatments were greater than those in the control treatment, although the differences were not statistically significant (P > 0.05). Additionally, the study revealed a direct proportionality between the average weight of experimental fish and the hormone concentration. Based on these findings, the recommended dose for achieving maximum mono-sex female climbing perch is 2 mg/L of 17β-estradiol.

The objective of this study was to evaluate the effects of daily dietary supplementation of Saccharomyces cerevisiae-contained product (SCP) on feed consumption, milk yield and quality of milking cows under Vietnam weather condition from November 2022 to January 2023 at the dairy farm of ANOVA Binh Duong. The study was conducted using a total of 94 Holstein Friesian (HF) crossbred cows with at least 3/4 HF blood, with days in milk (DIM) at days, and lasted 30 days (the first 15 days for the control without SCP supplementation (control) and the next 15 days for the SCP treatment with SCP addition at 5 g/cow per day (SCP). Results showed that the average feed intake (as fed) of cows in the control period was significantly lower than that of cows in the SCP period (P < 0.01). The SCP supplementation did not affect (P > 0.05) the milk productivity and milk fat, while milk protein, lactose, and solids not fat (SNF) from the milk of cows in the SCP group were significantly improved (P < 0.01). The SCP supplementation also significantly enhanced (P < 0.05) the body condition score (BCS) of dairy cows. Briefly, these results suggest that the dietary SCP addition of 5 g/cow per day seems to significantly improve the feed intake, BCS and milk quality parameters of lactating cows.

Polyphenols are secondary compounds that occur widely in plants and are highly effective in controlling plant pathogenic microorganisms. This study aimed to screen polyphenolic-rich plant extracts for their antifungal potential against Fusarium oxysporum. Several plant materials including cashew leaves, castor fruits, castor leaves, coffee husks, giant milkweed leaves, mangosteen pericarps and soapberry fruits were investigated for their total phenolic content. The results showed that cashew leaves and mangosteen pericarps contained high level of polyphenols at 108.23 and 124.14 mg GAE/g, respectively. The main phenolic compounds found in cashew leaves were gallic acid and protocatechuic acid at 377.29 mg/100 g and 56.44 mg/100 g, respectively. Mangosteen pericarps contained 16.22 mg/100 g protocatechuic acid and 55.75 mg/100 g of chlorogenic acid. The antifungal activity of cashew leaf and mangosteen pericarp extracts against F. oxysporum was 32.92 - 77.08% and 68.33 - 83.75%, respectively at the extract concentration from 2% to 10%. The combined use of cashew leaf and mangosteen pericarp extracts exhibited an additive inhibition against F. oxysporum. Cashew leaves and mangosteen pericarp are potential materials for producing bio-fungicides, which are not only effective but also safe for human and the environment.

The tassel fern, Huperzia squarrosa, is a rare and medicinally valuable plant known for containing Huperzine A. It propagates naturally through spores, rhizomes, cuttings, and clump division, but with a slow multiplication rate. This study aimed to optimize propagation conditions for H. squarrosa using stem cuttings and in vitro culture techniques to support its preservation and development. Apical and stem cuttings were treated with varying concentrations of indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA) before being planted in a substrate of coir dust, charcoal dust, and burnt rice husk (3:2:2). Apical cuttings treated with 1500 ppm IBA for 30 min showed the highest rooting success, identifying this method as optimal for propagation. Additionally, surface sterilization with a 40% bleach solution, followed by antibiotic treatment, achieved a 73.8% clean sample rate. In vitro culturing on ¼ MS (Murashige and Skoog) medium resulted in 70% survival and 55% rooting after 60 days. The highest callus formation rate (13.3%) was achieved with 0.01 mg/L IBA and 0.3 mg/L Kinetin, while the addition of 3 mg/L Glutamine did not significantly enhance callus induction. Ongoing research focuses on enhancing complete plant regeneration and improving the efficiency of in vitro propagation for H. squarrosa.

This study was conducted to determine the phytochemical composition of bitter melon seeds (Momordica charantia L.) grown in Long An province (Vietnam), to investigate optimal conditions for lipid extraction, and to evaluate the extracted lipid’s quality. The seeds had a moisture content of 5.27%, total ash of 1.85%, total flavonoid content of 91.10 mg/100 g, and total polyphenol content of 478.95 mg/100 g. The seeds were also free of highly toxic metals such as lead and cadmium. Using the Soxhlet method, optimal lipid extraction was achieved with a material-to-solvent ratio of 1:80 (w/v) over 4 hours, resulting in a lipid extraction efficiency of 13.74%. The acid, saponification, ester, and peroxide values were 1.01 mg KOH/g, 355.60 mg KOH/g, 354.59 mg KOH/g, and 3.82 meq O2/kg, respectively, in compliance with the quality requirements of Vietnam and Codex standards. The extracted lipids had antioxidant activity at an IC50 value of 119 mg/mL and inhibited the growth of two microbial strains Staphylococcus aureus and Bacillus subtilis subsp. spizizenii. These findings suggest that bitter melon oil has potential applications in the food, pharmaceutical, and cosmetic industries.

Land use and land cover (LULC) change is a key factor influencing land surface temperature (LST) dynamics. This change reflects partly global warming and climate change at local and regional scales. This study aimed to evaluate the effect of LULC on LST change in Lac Duong mountainous district, Lam Dong province in the past 10 years (2013 - 2023), and predict the LST change in 2030. The study used satellite image data from Landsat 8 and 9 OLI to build LULC and LST maps and used the CA-ANN model to predict the LST map. The results showed that the forest land had the LST below 25°C, with the below 20°C LST area correlated negatively with the forest land area, while 20 - 25°C LST correlated positively, especially at the temperature of 22 - 25°C (R2 = 0.97). The 22 - 25°C and 30 - 35°C temperature levels (R2 = 0.76 and R2 = 0.86) correlated sharply with the crop land area. The LST levels between 30 - 40°C reflected the built-up land and bare land with the highest correlation of R2 = 0.68 and 0.88, respectively. The LST level 20 - 22°C represented the water body area (R2 = 0.87). The LULC changes had an impact on the LST change in the past 10 years in Lac Duong district. While the forest land area decreased slightly by 0.5%, the cool LST area fell considerably by 10.5% compared to 10 years ago. An almost doubling of the cropland area also led to a doubling in the 25 - 35°C LST areas. In addition, the 35 - 40°C LST level started to happen in several regions. The LST change was predicted to keep increasing in 2030. The temperature was predicted to increase by 2 - 3°C with a maximum temperature of 42°C.

Currently, to monitor water quality, farmers in Vietnam need to analyze various indicators which increase production costs. In addition, the limitation of analytical facilities and techniques is a challenge. The objective of this experiment was to evaluate the influence of water quality parameters on shrimp growth rates and the seasonal fluctuation in water quality. A total of 4 modules were randomly selected and analyzed daily for 8 critical parameters during rainy and dry seasons. The SPSS ver.26 was used to evaluate the correlation between multi-parameters and their impact on the performance of shrimp ponds. The results showed that shrimp growth was influenced by salinity, nitrite (NO2-), alkalinity and pH about 80.4%, 75.6%, 67.8%, and 55.7%, respectively. Moreover, water quality fluctuated more during the rainy season than during the dry season. Some parameters that exhibited high fluctuation in ponds were dissolved oxygen (DO) and nitrite.

The Mekong Delta is regarded as the granary of Vietnam, with an annual production of 24.1 million tons (2023). Currently, fresh paddy is transported directly from farmers’ fields to drying facilities or rice mills. Given the extensive river and canal system in the Mekong Delta, the majority of paddy (up to 92%) is transported by barges. While barge transportation is more costeffective (91,000 VND/ton for a 100 km distance) compared to truck transportation (269,000 VND/ton), it has significant drawbacks, such as a longer transportation time of 3 to 5 days. Moreover, because the paddy is wet during transport, it is prone to discoloration (yellowing), which reduces its quality. To address this issue, this research developed an experimental paddy aeration model as a foundation for implementing aeration on barges during transportation. The model was tested with 1.4 tons of fresh paddy, specifically the DT80 variety, in Cai Lay, Tien Giang province. Key parameters monitored and analyzed included paddy temperature, moisture content, ambient conditions, and grain quality. The model was tested with a specific airflow rate of 129 ± 23 m3/h per ton. The paddy temperature in the aeration model was maintained at 28.8°C, similar to the ambient temperature of 28.3°C. As a result, the whiteness of the aerated paddy was preserved at 3.6% after three days, whereas it decreased from 3.6% to 3.2% in paddy transported without aeration. The application of aeration helped reduce quality losses, particularly discoloration, caused by the high temperatures of fresh paddy during transportation.

Agricultural bio-catalysis is of immense scientific interest due to its increasing importance in the efforts for more sustainable agriculture while optimizing environmental impacts. In our studies, native rice starch was hydrolyzed with various alpha-amylase concentrations (0, 0.1, 0.2, and 0.3% w/w of starch) at 50°C for 20 min; then purified by partial precipitation (PP) with organic solvents, or freeze-drying (FD) without further purification. The rice starch hydrolysates (RSH) produced by different methods (PP or FD) were determined for dextrose equivalent (DE), morphology, and some physicochemical properties including bulk density, moisture content, hygroscopicity, and water solubility. The results showed that at the same alpha-amylase treatment conditions, the RSH obtained by the PP method had lower DE values and production yields than those of RSH obtained by FD method. The FD-RSH had higher DE values, lower bulk densities and moisture contents, higher hygroscopicity and water solubility. In morphology, the PP-RSH (DE 10.2) had a larger particle size and more condensed microstructure compared to the FD-RSH of almost similar DE 13.5. These findings showed that the PP method resulted in lower-DE RSH with different morphological and physicochemical properties compared to those obtained by the FD method.