The Journal of Agriculture and Development

●The Journal of Agriculture and Development (JAD) is an international and peer reviewed journal publishing novel and significant research in a wide range of topics such as Agribusiness and Economics, Agricultural Mechanics, Agronomy and Forestry Sciences, Animal Sciences, Aquaculture and Fisheries, Biotechnology, Enviromental and Natural Resources, Food Science and Technology, and Veterinary Medicine. The JAD is an open access journal that includes primary research, review articles, short communications, and special invited papers. We also publish special issues which focus on the current emerging topics in agricultural sciences.

●The JAD (the formerly named Journal of Agricultural Science and Technology) is published in 6 issues per year (4 issues in Vietnamese with English abstracts and 2 issues in English). The journal has published over 19 volumes since 2002.

●Period of publication: Issue 1 (FEB), Issue 2 (APR), Issue 3 (JUN), Issue 4 (AUG), Issue 5 (OCT), Issue 6 (DEC)

●Publisher: Nong Lam University, HCMC (NLU)

Application of loop-mediated isothermal amplification to detect Salmonella spp. in egg samples

Kha T. Tran, & Trang T. P. Nguyen
Electronic version: 01 Jun 2023 | DOI: 10.52997/jad.1.03.2023
Abstract | pdf (3.5M)

Abstract

The objective of the study was to evaluate the use of loop-mediated isothermal amplification (LAMP) technique for detection of Salmonella spp. in chicken eggs. Eight Salmonella strains and 26 non-Salmonella enteric strains were used to verify the specificity of the LAMP assay for detection of Salmonella. The Sal4 primer set was used to specifically amplify the target sequence on the invA gene of Salmonella and the hydroxyl naphthol blue was used as the indicator to read the reaction results. Blank egg samples were spiked with serial 10-fold diluted Salmonella suspensions to determine the limit of detection at 50% (LOD50) of the assay. Egg samples collected from multiple locations in Ho Chi Minh City were tested for the presence of Salmonella using both LAMP method and the traditional culture method to compare the effectiveness of these two methods. Among 34 bacterial strains tested by LAMP assay, false-positive or false-negative results were not observed. The assays of spiked egg samples showed that the LOD50 of the LAMP method was less than 2 CFU/25 g sample. These results indicated a high specificity and sensitivity of the LAMP assay in detection of Salmonella in egg samples, even with those of low levels of contamination. Upon testing collected egg samples (n = 42), the LAMP assay produced the same results of Salmonella detection as the culture method. Salmonella was detected in 4 out of 42 samples. This study showed that the LAMP method is highly effective and would be suitable for use in detection of Salmonella in egg samples. The assay has several advantages such as saving time and labor compared to traditional culture methods.

Efficiency of intensive tilapia culture in earthen ponds applied biofloc technology (BFT), probiotics and off-flavor control methods

Loan P. Phan, & Tu V. Nguyen
Electronic version: 01 Jun 2023 | DOI: 10.52997/jad.2.03.2023
Abstract | pdf (3.8M)

Abstract

The aim of this study was to assess the efficiency of Nile and red tilapia cultured in intensive systems applied a combination of biofloc technology (BFT) and probiotics in earthen ponds with different methods to control the off-flavor problem. A growing-out experiment was conducted for 150 days in which both Nile tilapia (5.88 ± 0.59 g) and red tilapia (9.72 ± 0.72 g) fingerlings were randomly allotted into three replicates of earthen ponds which were subdivided into four treatment groups, including: off-flavor controlled by algae management in Nile tilapia ponds (NT - AM) and red tilapia ponds (RT - AM), and off-flavor controlled by active water exchange in Nile tilapia ponds (NT - WE) and red tilapia ponds (RT - WE). The results showed that water quality was maintained in suitable ranges for fish growth. There were no significant differences in growth performance (final weight, daily weight gain and specific growth rate) among all treatments (P < 0.05). Feed conversion ratio of Nile tilapia (1.28 - 1.31) was significantly lower than that of red tilapia (1.35 - 1.37) (P < 0.05). The survival ratio (about 80%) and extrapolated yield (21.50 tons/ha in 150 days) of fish was similar and high for both Nile and red tilapia. The quality of the harvested fish in term of condition factor, size even and off-flavor intensity was also excellent. The economic efficiency of red tilapia farming in this system was higher as compared to cage systems. This study clearly demonstrated that the technique of combined BFT and probiotic application in earthen ponds could contribute to the sustainable development of tilapia production in Vietnam by reducing production cost, saving water resource and avoiding environmental pollution.

Isolation and characteristics of Pseudomonas fluorescens to inhibit Phytophthora palmivora causing rot disease in durian

Van T. Tran, Ha T. Nguyen, Hang T. Nguyen, & Don D. Le
Electronic version: 01 Jun 2023 | DOI: 10.52997/jad.4.03.2023
Abstract | pdf (3.3M)

Abstract

Plant growth promoting Rhizobacteria (PGPR) have long been selected as biocontrol agents for plants. The PGPR are beneficial bacteria that live in plant roots and enhance plant growth by various of mechanisms. The PGPR have many species of the bacterial genus Pseudomonas, in which the Pseudomonas fluorescens strains is suitable for application as a biocontrol agent due to its abundance in natural soil and plant root systems. Pseudomonas fluorescens strains have important characteristics such as the ability to adhere to soil particles and to rhizomes, the ability to synthesize antibiotics, and to produce hydrolytic enzymes. Furthermore, P. fluorescens strains also possess plant growth promoting characteristics such as proteolysis, phosphate solubilization, iron chelation, and phytohormone production. Durian is a crop that has been expanded in Southeast Asian countries but the rate of durians infected with root, stem and fruit rot caused by P. palmivora is quite large. In this study, five native P. fluorescens isolates were isolated from 70 soil and rhizome samples collected from 10 durian growing provinces and evaluated for their ability to antagonize P. palmivora in petri plates. These isolates were gram negative, small, single isolated rods without sporulation when observed under microscope. All of them tested positive for catalase test, oxidase test, starch hydorolysis, gelatine liquefaction, H2S, citrate utilization and negative with indole, Voges-proskauers, methyl red. All of 5 native P. fluorescens isolates were capable of phosphate solubilizing activity, N2 fixation, siderophore and IAA production. The study showed that P. fluorescens P. fDN strain was able to inhibit P. palmivora causing rot disease in durian with 51.85% inhibition of radial growth.

Improving the database on land use planning in Vung Tau city, Ba Ria - Vung Tau province

Linh D. T. Truong
Electronic version: 01 Jun 2023 | DOI: 10.52997/jad.6.03.2023
Abstract | pdf (4.2M)

Abstract

Vung Tau city is an area where management of land use planning (LUP) and urban planning is quite complicated and has been successful in building LUP database. However, this database still has limitations that must be addressed, including (1) lack of data layer on current land use for building LUP database, (2) incompleted LUP attribute database, (3) lack of metadata, (4) no connection between LUP database and digital legal materials and (5) no overlay cadastral database to data layer of current land use and LUP database. To solve these problems, this research used many methods such as documents and data collection, inheritance, expert interview, data processing and analysis, mapping, GIS application, and IT applications. The results of this study showed that the structure of cadastral database of 8 wards was succesfully converted from existing structure (according to Circular 17/2010/TT-BTNMT) to the standard structure (according to Circular 75/2015/TT-BTNMT). The 2019 land inventory data was standardized and data layer of current land use for whole city was built. In addition, the LUP database (period 2010 - 2020) for Vung Tau was improved, including: supplementing attribute information, completing metadata, connecting LUP database with relevant digital legal records, overlaying cadastral database with LUP database and data layer of current land use. Briefly, our results could be a foundation to help Vung Tau manage land sustainably, contribute to successfully building national land database and meet the exploitation requirements of LUP information in accordance with the orientation of Ministry of Natural Resources and Environment for study area.

Water desalination of Chlorella vulgaris

Hau T. T. Nguyen, Giang T. K. Ho, Huong T. Nguyen, Sang M. Nguyen, Suong T. Nguyen, Duy N. Dao, & Viet B. Nguyen
Electronic version: 01 Jun 2023 | DOI: 10.52997/jad.5.03.2023
Abstract | pdf (2.8M)

Abstract

Saltwater intrusion is a common phenomenon in Southern Vietnam, but salinization is becoming more serious due to the rising sea level related to climate change. Among potential methods for water desalination, the application of halophytic microalgae is gaining high interest. This study investigated the effect of Chlorella vulgaris (C. vulgaris) microalgae on reducing water salinity at different media (Bold Basal Medium and Sea Salt Medium) and in different salt concentrations (1 - 30 g/L). The results indicated that C. vulgaris microalgae had good growth in all mediums used and contributed to lowering the salt content from 20% to 40% after 15 days of cultivation.
Most Read
  • Influence of stocking density on water quality and growth performance of whiteleg shrimp (Litopenaeus vannamei) reared in fiberglass tanks, without water exchange
    Electronic version: 27 Dec 2019 | DOI: 10.52997/jad.3.06.2019
    Abstract | PDF (3.4M)

    Abstract

    The present study evaluated the effects of stocking density on water quality parameters, growth performance and survival rate of white leg shrimp Litopenaeus vannamei, reared in fiberglass tanks, without water exchange. Three stocking densities (50, 100 and 200 shrimp/m2) were tested. Each treatment consisted of three replicate fiberglass tanks (500 L). The shrimp were fed ad libitum four times per day with a commercial pellet (40-42% protein). After an 8-week trial, concentrations of nutrients in the culture tanks showed an increasing linear relationship with increasing stocking density. The growth performance of shrimp in low stocking densities was significantly greater than that in high stocking densities. The results from this study demonstrate that with increasing the stocking density the production of shrimp increased but n a low final weight and survival compared to low stocking density.
  • Relationship between the ratio of villous height:crypt depth and gut bacteria counts as well production parameters in broiler chickens
    Electronic version: 30 Jun 2021 | DOI: 10.52997/jad.1.03.2021
    Abstract | PDF (878.8K)

    Abstract

    The villous height to crypt depth (V:C) ratio is one of the most significant parameters which is associated with the nutrients’ absorption and greater body weight. The objective of this study was to assess the relationship between V:C ratio, gut bacteria counts and production parameters in broiler chickens. A total of 100 individual broilers were randomly selected from a farm with 40,000 Ross 308 chickens and slaughtered for sampling at three different ages including 14, 28 and 37 day old. Villous height and crypt depth were measured for each section of the small intestine to calculate V:C ratio. Intestinal score and gut microbiology including total coliforms, lactic acid bacteria and Salmonella prevalence were assessed. At day 37, besides those parameters, the carcass, breast, legs and wings were taken for weight measurements. Leg and breast color was also measured. Data were statistically analyzed by STATA software to explore the relationship between V:C and those parameters. The results showed the positive correlation between V:C of duodenum and the number of lactic acid bacteria at 28 days of age (P < 0.05). Moreover, the leg yield was negatively related to the V:C ratio of jejunum (P < 0.05). No significant correlations were found between V:C ratio and other parameters. The results indicated the potential of controlling V:C ratio to improve gut health and meat quality of broiler chickens and thus, further studies should be conducted to fully evaluate these correlations.
  • Field assessment of the efficacy of M.B., LIBDV and Winterfield 2512 strain vaccines against infectious bursal disease in chickens
    Electronic version: 31 Dec 2018 | DOI: 10.52997/jad.3.06.2018
    Abstract | PDF (260.1K)

    Abstract

    Live virus vaccines are very important parts of the prevention of Infectious Bursal Disease (IBD) in chickens. However, the successful IBD vaccination depends on IBD field pressure, vaccination technique, the immune status of the chicken, and especially IBDV strains used in the vaccines which are able to break through a higher level of maternal-derived antibodies (MDA). The objective of this field study was to compare the efficacy of a new vaccine based on M.B. strain to other commercial vaccines (LIBDV and winterfiled 2512) in terms of speed of antibody immune response and interference to Newcastle Disease (ND) vaccination. Six houses of broilers, each with 15,000 to 16,000 chickens, were divided into two groups: (1) vaccinated with M.B. strain (group A) and (2) vaccinated with LIBDV or 2512 strains (group B). Blood samples were collected prior to the 1st IBD vaccination, and at 21, 28 and 35 days of age for IBD and ND antibodies. Comparison of lesion scores and uniformity of the bursa of Fabricius (BF) at 28 and 35 days of age was carried out. Results showed that both groups had good immune responses, but group A showed significantly higher IBD antibody titers at 28 and 35 days of age. Antibody titers for ND and histopathological lesion scores of the BF were not significantly different between the 2 groups. The BF in group A was more uniform and had fewer lesions when compared with that in group B. In conclusion, the IBD vaccine with an M.B. strain can provide better immunological efficacy than LIBDV and 2512 strains.
  • Starch recovery from turmeric powder (Curcuma longa) after ethanol curcumin extraction in comparison to the conventional method
    Electronic version: 30 Dec 2021 | DOI: 10.52997/jad.8.06.2021
    Abstract | pdf (812K)

    Abstract

    Recovery starch from organic waste significantly contributes to sustainable agricultural production. This study aimed to recover starch from the waste mimicking generated from the curcumin extraction by using ethanol. The physicochemical properties of the isolated starch such as microscopic morphology, Fourier transform infrared spectroscopy, X-ray diffraction, total starch, iodine binding capacity of starch, curcumin content determined by high-performance liquid chromatography were compared to that of starch obtained from the conventional method of extraction from the fresh rhizome.  The results showed that the starch obtained from the fresh rhizome had a higher yield (21.3% vs. 8.5%) compared to that of starch isolated from the turmeric powder after extracting curcumin. The total starch analysis indicated that the former starch had a higher purity (98% vs. 77%, dw). The SEM imaging showed that both starches had irregular shapes with a thick flat and smooth surface. Although the starch isolated from the turmeric powder showed the dedicated properties of starch, the peak intensity and crystalline structure were remarkably decreased, observed under FTIR and X-ray diffraction analyses, respectively. The pasting analysis showed a clear change in starch obtained from the turmeric powder after ethanol extracting curcumin since a low peak viscosity was recorded. The HPLC curcumin quantification showed that both starches had a very low residue of curcumin (18.4 mg/100 g and 66.5 mg/100 g, dw) after isolation. The process of recovery starch after curcumin extraction from turmeric would be further improved to prevent the changes in physicochemical properties and for better yield.
  • The effects of plant spacing on yield and quality of butterfly pea (Clitoria ternatea L.) cultivated in organic-oriented farming system on grey soil
    Electronic version: 30 Jun 2020 | DOI: 10.52997/jad.2.03.2020
    Abstract | PDF (260.1K)

    Abstract

    Clitoria ternatea L. is a plant species that can be used in food and pharmaceutical industry. This study was conducted to evaluate the effects of different plant spacing on the productivity and quality of butterfly pea grown on grey soil in Thu Duc, Ho Chi Minh City. Six treatments correspond to plant spacing of 80 x 15 cm, 80 x 20 cm, 80 x 25 cm, 80 x 30 cm, 80 x 35 cm and 80 x 40 cm. The results showed that the highest flower amount (296.8 flowers/plant) was obtained with butterfly pea planted at the spacing of 80 x 15 cm, commercial flower weight (7.86 g/100 flowers), theoretical yield of fresh flower (1,779.0 kg/1,000 m2, actual yield of fresh flower (841.9 kg/1,000 m2), theoretical yield of commercial flower (194.6 kg/1,000 m2 and actual yield of commercial flower (89.0 kg/1,000 m2. Nevertheless, plant spacings did not affect the dry matter ratio, anthocyanin and tannin content in the commercial butterfly flowers.