Vietnam Journal of Agricultural Sciences

This study aimed to assess the combined effects of salinity and drought stresses on the growth and physiology of sugarcane. The pot experiment was carried out in the Autumn cropping season of 2021 under the polyhouse conditions at the Vietnam National University of Agriculture. The experiment consisted of four treatments: non-stress treatment (control), drought stress, salt stress, and salt and drought stress (combined stress). Five weeks after transplanting, salt stress was applied first for four weeks and followed by drought stress for another two weeks. The results showed that under the impact of stresses, sugarcane growth was inhibited with decreases in plant height, number of leaves, Fv/Fm, SPAD, and the fresh and dry weights of roots and stems. The growth and physiology indicators were the lowest under the combined effects of salinity and drought stress.

Fertilizers play an important role in enhancing crop yield, growth, and fertility of the soil. This research was conducted at the Faculty of Agriculture teaching and research farm, University of Port Harcourt, Nigeria to investigate the influence of inorganic fertilizer (urea) and organic manure (spent mushroom substrate and poultry manure) on the yield and growth parameters of three okra cultivars (Clemson Spineless, Perkin Long Pod and the Local Assertion). The urea was applied at the rate of 4g per 10kg of soil, while spent mushroom substrate and poultry manure were applied at the rates of 200g and 150g per 10kg of soil respectively at 4 weeks after planting. The treatments were laid in a completely randomized design (CRD) with 3 replications. The results revealed that the okra cultivars responded positively to both organic manures when compared with urea and the control group where no fertilizer was applied. Furthermore, varieties grown with poultry manure generally had the highest fresh fruit weight, plant height, fruit length, number of fruits, and fresh fruit yield. Spent mushroom substrate influenced the number of fruits and fruit yield while urea influenced the leaf area, number of leaves, and leaf area index. Poultry manure was recorded as the best organic manure for okra growth and yield and is recommended to be used to grow okra plants. Also, the Perkin Long Pod variety is recommended to be the best for cultivation.

Fifteen hybrid combinations developed by crossing five lines and three testers were assessed for milling and physio-chemical qualities to evaluate the combining ability of the parents using a line x tester design. This investigation provided information about the general combining ability (GCA) of parents and the specific combining ability (SCA) effects of crosses from eight popular inbred varieties. C70 was considered the best general combiner for the head rice recovery trait, while the crosses involving C70 with DH18 and CR203, 13/2 with TBR225 and Xi23, and OM6976 with TBR45 showed significant positive specific combining ability (SCA) effects. Xi23 and OM6976 among the lines showed significant general combining ability (GCA) effects indicating them to be good general combiners for obtaining hybrids with desirable (low or intermediate) properties of amylose content. The variances due to SCA were of greater magnitude than GCA for all the traits, revealing the preponderance of non-additive gene action for all the studied attributes. In all the studied quality traits, the narrow sense heritabilities were ordered as follows: head rice recovery > amylose content > gel consistency > alkali digestion > hulling percentage > milling percentage. The narrow sense heritabilities in these traits were quite low, ranging from 8.11% to 14.4%. Among the eight parents, C70, Xi23, and TBR225 were the most ideal for high-quality line breeding.

Probiotics are vital in aquaculture for maintaining water quality, boosting aquatic species' health, and enhancing growth rates. This study investigated the effects of probiotics, namely salt-tolerant Bacillus velezensis MT50 and Bacillus amyloliquefaciens MT51, on the water quality and performance of whiteleg shrimp (Litopenaeus vannamei PL) cultured in tanks. The experimental design included two bacterial treatments and one control treatment (without Bacillus), with each treatment replicated three times. The results indicated that temperature, pH, and total alkalinity varied within the ranges of 27.8 to 28.9°C, 7.81 to 7.94, and 98.5 to 114.7 mg CaCO3 L-1, respectively, and all were maintained at appropriate levels. Additionally, other parameters such as dissolved oxygen (DO), chemical oxygen demand (COD), total suspended solids (TSS), and total ammonia nitrogen (TAN) exhibited less fluctuation in the treatments supplemented with Bacillus sp. compared to the control. Furthermore, the densities of pathogenic agents (e.g., Vibrio) in tanks with the addition of MT50 and MT51 bacteria (102 and 101 CFU mL-1, respectively) were significantly lower than in the control tanks (104 CFU mL-1). The survival rates of shrimp treated with MT50 (70.0 ± 5.3%) and MT51 (86.7 ± 3.1%) were significantly higher (P <0.05) compared to the control group (65.3 ± 3.1%). These findings suggest the potential application of B. velezensis MT50 and B. amyloliquefaciens MT51 as probiotics for sustainable aquaculture practices.

This research was undertaken to determine the concentrations of heavy metal ions in the surface water and sediment in water bodies that receive wastewater from the Dinh Tram and Pho Noi A industrial zones. The pollution status of the heavy metal ions and their potential ecological risks were evaluated by using the potential ecological risk index (RI) and risk assessment code (RAC). The results showed that some metal ions, namely Fe3+, Ni2+, and Pb2+, exceeded the allowed standards of QCVN 08:2023/BTNMT. The sediments were polluted by Zn2+, As2+, Cr6+, and Fe3+ at concentrations 2.4, 3.7, 1.9, and 2.0 times higher, respectively, than the QCVN 43:2017/BTNMT. The potential ecological risk indices for the heavy metal ions were in order as: (As2+) = 7.94 > (Cd2+) = 3.68 > (Cr6+) = 3.39 > (Pb2+) = 2.73 > (Cu2+) = 2.74 > (Zn2+) = 2.4 (T6 channel) and (As2+) = 11.1 > (Cd2+) = 7.74 > (Cu2+) = 2.64 > (Cr6+) = 2.31 > (Pb2+) = 1.9 > (Zn2+) = 0.87 (Bun River). The risk assessment code (RAC) ranged from 0.17 to 39.42 (T6 channel) and from 0.03 to 38.96 (Bun River). The RAC-based risk assessment results showed that both the T6 channel and Bun River presented a medium risk for Cd2+, a low risk for Mn2+, Zn2+, Cu2+, and Ni2+, and no risk for the remaining metals, Cr6+, Pb2+, As2+, and Fe3+. These results were caused by the differences in environmental quality assessments between using separate parameters versus biological risk assessments.

This study aimed to analyze the status of the economic linkage between farm households and Orion Vina Food Co., Ltd. enterprise in potato production and selling in Dong Trieu town, Quang Ninh province. The study was conducted through in-depth interviews with 136 farm households (62 linked and 74 unlinked) with the direct interview survey method, and collected data were processed using SPSS. The binary logit model was used to analyze the factors affecting the decision of farm households to join the linkage. The research results showed that the linkage brought benefits to both the farm households and the enterprise, but there are still some limitations. The decision of households to join the linkage was influenced by factors such as production area, production experience, agricultural extension training, and membership in a cooperative. In order to promote economic linkages between farm households and the enterprise, the solutions that need to be implemented include: i) Raising farmers' awareness about the role of linkages in potato production and selling; ii) Strengthening support for farmers in terms of the enterprise providing technology and inputs for production and purchasing potatoes; and iii) Encouraging the local government to support the establishment of cooperatives, strengthen agricultural extension training to attract households to join the linkage, and increase the efficiency of potato production in the town.

Under the impacts of the 4th Industrial Revolution, garment firms in Vietnam are facing various challenges, and improvement in their labor productivity is one of the important measures to overcome these challenges. This study, therefore, investigated the determinants of the labor productivity of garment firms in Nam Dinh province. The data used for this study were extracted from the Enterprise Survey Dataset in 2021, and descriptive statistics, comparative analysis, and the Cobb-Douglas function in logarithm form were the major methods employed for the study. The study findings underscored the positive impacts of fixed assets and business management costs, average payments to employees, exporting activities, and the utilization of internet resources on labor productivity. The study revealed that firm size, gender composition, and age of firm leaders do not significantly influence labor productivity, emphasizing the complexity and industry-specific nuances of these relationships. Based on the insights gained from the study, several strategic suggestions were proposed to improve the labor productivity of garment firms in Nam Dinh province in the future.