Published: 2022-06-30

Factors affecting the relationship quality between coffee farmers and local traders: A case study in a highland commune of Dak Lak, Vietnam

Hoa T. T. Ha, Hoa L. Dang, Nhung T. H. Pham, & Dang B. Nguyen
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.1.03.2022
Abstract | pdf (734.7K)


The study examines factors affecting the relationship quality between coffee farmers and local traders. This study uses data collected from 201 coffee farmers. The results show that there are five factors affecting the relationship quality, including collaboration, perceived price, profit/risk sharing, power asymmetry, and effectiveness communication. Profit/risk sharing is the most important factor positively influencing the relationship quality between coffee farmers and local traders while power asymmetry negatively affects the relationship quality. The study also claims that relationship quality positively impacts farmers’ profit and relationship continuity intention between coffee farmers and local traders. Policymakers should focus on increasing transparency and information sharing between coffee farmers and local traders to improve relationship quality.

Factors influencing the adoption of “One Must Do, Five Reductions” in rice production in the Mekong River Delta: A case study in Soc Trang province, Vietnam

Thuy N. Nguyen, & Ha H. Anh
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.2.03.2022
Abstract | pdf (402K)


After years of experimenting, the “One must do, five reductions” (1M5R) (in Vietnam referred to as 1P5G) is being promoted by Vietnam’s Department of Crop Production as an advanced technique in rice production. Nevertheless, a certain proportion of rice farmers in the Mekong Delta are reluctant to implement 1M5R. This study collected data from 116 rice farming households in Soc Trang province to assess factors influencing the decision to adopt the new technique. The result showed that the 1M5R model offers better economic efficiency than the traditional producing model in terms of profit, revenue/cost ratio, and profit/cost ratio. The estimated Binary Logistic model revealed that labor, production experience, and production area significantly contribute to farmers’ adoption of 1M5R. These results are empirical evidence of the potential of 1M5R, which supporting its promotion in Vietnam’s Mekong River Delta

Effect of three different organic fertilizers on growth, yield, and essential oil content of basil (Ocimum basilicum var. pilosum)

Trang T. H. Nguyen, Truong V. Nguyen, Hoa T. Pham, Thao X. Nguyen, Nhat P. Nguyen, Tan N. C. Tran, & Quang T. Le
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.3.03.2022
Abstract | pdf (457.9K)


Basil (Ocimum basilicum var. pilosum) is an herbaceous plant species exhibiting various economic and medicinal values. This study was conducted to determine the effect of three different organic fertilizers, namely cow manure, worm castings manure, and Komix organic fertilizer, on the growth, yield, and essential oil content of basil in Thu Duc City. The results showed that using worm castings manure (25 tons/ha) decreased the growth parameters including the average height of main stems and the average number of leaves and lateral branches, whereas increased significantly the plant height (41.8 cm), stem diameter (6.0 mm), number of primary branches (13.5 branches), number of leaves (16.8 leaves), chlorophyll index (41.3) and number of shoots after regeneration (20.2 shoots), compared to the control. Besides, using worm castings manure (25 tons/ha) also helped increase the average fresh weight of basil stems and leaves (93.3 g/plant), theoretical yield (24.9 tons/ha), actual yield (14.7 tons/ha), essential oil content (0.5 mL) /100 g), and yield of essential oil (1.1 L/ha). The study also confirmed that using worm castings manure (25 tons/ha) created the highest economic efficiency with total profit reaching 737,570,000 VND/ha/3 harvests while using worm castings manure at a rate of 5 tons/ha gave the highest real rate of return (3.26).

Effects of different loading densities during transport on survival rates of Asian seabass (Lates calcarifer Bloch, 1790) juvenile

Nhan T. Dinh, & Tu V. Nguyen
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.5.03.2022
Abstract | pdf (486.4K)


This study was carried out to evaluate effects of loading density on water quality and survival rate of Asian seabass (Lates calcarifer) juvenile during live transport. The experiment included four treatments of different biomass: 50 kg/m3 (T1), 70 kg/m3 (NT2), 90 kg/m3 (T3) and 110 kg/m3 (T4) with three replicates for each treatment. The fish with an average weight of 20.50±0.25 g and length of 11.52±0.22 cm were fasted for 24 h before transporting in aerated and oxygenated heat-insulating tanks. The water temperature in transport was set at 22⁰C and the concentration of isoeugenol was 6 ppm. The fish was acclimatized to the transport temperature by gradually cooling water with ice to 22⁰C for 30 minutes. Then, fish were transferred to transport tanks containing 40 L water and closed with lids. After transporting, the fish were kept in hapas suspended in an earthen pond with routine management. Water quality and survival rates of the fish were recorded after transport 6 h and 12 h (end of experiment), and 3 and 7 days after the end of transporting. The results showed that the water quality was declined expressed by the decrease of DO and pH, and the increase of CO2, TAN and NO2 during transport but still in suitable ranges for seabass. The survival rates of the fish of all treatments were reduced following transport duration. The fish were well recoverd after the transport. At the end of the study, the survival rate of the fish of T1 was highest (96.00%), followed by T2 (95.33%), T3 (90.00%) and T4 (87.63%). Based on accumulated mortality, loading biomass of 70 to 90 kg/m3 and 50 to 70 kg/m3 were reccomended for live transport of seabass juvenile in cooling water (22⁰C) and sedation with isoeugenol (6 ppm) during 6 h and 12 h, respectively.

Detection of Newcastle disease virus and H5-subtype Influenza virus in swiftlet houses by Multiplex reverse transcription PCR assay

Phat X. Dinh, Trinh T. Do, Lam G. Hoang, Nhu T. Q. Cao, & Mi T. M. Nguyen
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.4.03.2022
Abstract | pdf (562.7K)


The purpose of this study was to investigate the presence of Avian paramyxovirus 1 (APMV-1), also known as Newcastle disease virus (NDV), and Avian influenza type A, especially H5 subtype (AIV-H5) in swiftlet houses and swiftlet nest by multiplex RT-PCR (mRT-PCR). The assay used two specific primer pairs designed to detect the conserved sequence of the F gene of NDV and the HA gene of the AIV-H5, with product sizes of 282 bp and 420 bp, respectively. The mRT-PCR was established with detection limit of 25 copies/reaction for each target virus. The thermal cycle was optimized as follows: cDNA synthesis at 45ºC for 20 min, an initial denaturation at 95ºC for 5 min, followed by 35 cycles of amplification encompassing denaturation at 95ºC for 30 sec, annealing at 58ºC for 30 sec, and extension at 72ºC for 45 sec, ending by a final extension step at 72ºC for 7 min. Eighty-eight field samples including feces and swabs of the nest surface were examined and all samples were confirmed to be negative for these two viruses. The results of this study indicated that the swiftlet nests and the environment of swiftlet houses were not contaminated with NDV or AIV-H5 viruses. Moreover, the established mRT-PCR protocol had good specificity, detection limit, and can apply for routine veterinary diagnosis.

Two-step pretreatment for improving enzymatic hydrolysis of spent coffee grounds

Ly T. P. Trinh, Anh T. V. Nguyen, Anh Q. Nguyen, & Tat V. Nguyen
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.6.03.2022
Abstract | pdf (490K)


Spent coffee ground has attracted increasing attentions since it contains many useful components such as polysaccharides, protein, lipid and bioactive compounds. The aim of this research is to enhance the enzymatic hydrolysis to release important sugars in spent coffee ground using different pretreatment methods. Spent coffee grounds were pretreated by alkali pretreatment, organosolv pretreatment and the combined process. The pretreated material was hydrolyzed by different commercial enzymes including Cellulast, Pectinex, Ultraflomax and Viscozyme. Monosaccharides, total phenolic content and antioxidant activity in the hydrolysate were measured and evaluated. The use of Viscozyme achieved the highest reducing sugar yield and showed the significant difference from other enzymes. Alkali and organosolv pretreatment demonstrated to improve the production of sugars. The alkali pretreatment followed by organosolv treatment effectively removed lignin, resulting in only 14% lignin in the pretreated sample. The maximum reducing sugar concentration reached 6120 mg/L through two-step pretreatment and subsequent enzymatic hydrolysis, corresponding to a yield of 161 mg sugar/g substrate. The spent coffee ground hydrolysate contained 2917 mg/L mannose, 1633 mg/L glucose and 957 mg/L galactose. Phenolic compounds were observed to be released during the enzymatic hydrolysis, giving a total phenolic content of 174.4 mg GAE/L and the SCG hydrolysate also showed an antioxidant capacity equivalent to 263.2 mg/L ascorbic acid after 120 h hydrolysis. This study demonstrated a scalable two-step pretreatment process to obtain important sugars including mannose, glucose, and galactose along with phenolic compounds for further industrial uses.

Assessment of surface water quality and some main rivers’ capacity of receiving wastewater in Ca Mau province, Vietnam

Tuan Q. Le, & Vuong K. Nguyen
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.7.03.2022
Abstract | pdf (1.5M)


Surface water from rivers plays a significant role in socio-economic development in Ca Mau Province. It supplies freshwater for agriculture and aquaculture. Faced with the pressures of development, surface water quality in Ca Mau Province has been being at stake. The aim of this paper is to assess the water quality status and wastewater receiving capacity of the main rivers of Ca Mau Province. The monitoring results and calculated Water Quality Index (WQI) indicated that almost surface water in Ca Mau Province was heavily polluted and did not meet the irrigation purpose. Most rivers and canals in Ca Mau City were not able to receive any more contaminant loads of COD, BOD5, N-NH4+, and P-PO43-. To protect the water resource for sustainable development, consequently, it is important to propose water management solutions for the local government to regulate wastewater discharge into surface water bodies in Ca Mau Province.

Evaluation of the production process of biodegradable drinking straws from corn kernel

Thanh T. Le, Tuyen C. Kha, Nguyen H. P. Nguyen, Phan T. H. Dang, Nhung T. Dong, & Thanh N. T. Le
Electronic version: 30 Jun 2022 | DOI: 10.52997/jad.8.03.2022
Abstract | pdf (544.2K)


New product development is one of the most effective methods to expand the economic value of corn, which is currently a low-cost agricultural material. The present study was conducted to determine the production process of straws from corn under the laboratory scale, in which the influence of mixing formula, steaming time, screw speed, and drying temperature on hardness and expansion time of the drinking straws from corn kernels. In addition, the biodegradability of the resultant straws was also tested in the natural environment. The study determined the most suitable recipe for producing the drinking straw product, including corn flour (75%), tapioca starch (20%), rice flour (5%), with the addition of 0.5% xanthan gum and 0.2% potassium sorbate (w/w). The operating conditions of steaming time (10 min), screw speed (40 rpm), and air drying temperature (40°C) were found to be the most appropriate. For the decomposition study, the results indicated that the drinking straw product was capable of decomposing after 40 days at a temperature 30 ± 2°C. As such, it can be concluded that it is highly potential to build up the production process of the drinking straws from corn kernels that are environmentally friendly and ease of practical applications.