Vol. 20 No. 10 (2022)

The study aimed to evaluate the effects of different levels of silicon fertilization on some physiological parameters and mineral nutrient uptake characteristics of mondo grass under non-irrigation conditions in Ha Hoa district, Phu Tho province. A two-factor experiment was conducted in a split-plot design on haplic Acrisols with 6 levels of silicon (0, 20, 30, 40, 50, 60kgSiO2/ha/year) and 2 varieties of mondo grass (G2 and G6). The results showed that the supplemental application of silicon reduced ion leakage and water saturation deficiency in both two mondo grass varieties. silicon application increased osmotic pressure, SPAD index, and chlorophyll fluorescence efficiency (Fv/Fm), thus enhancing photosynthesis of mondo grass under non-irrigation conditions. The absorption of N, P2O5, K2O, SiO2and the content of polysaccharides, saponins, and flavonoids in the roots and tubers tended to increase with increasing amount of silicon application. The variability of polysaccharides between formulations was found to be lower than that of saponins and flavonoids. On haplic Acrisols, applicationpf 40kgSiO2/ha and basal application of 30kg N/ha + 30kg P2O5/ha + 30kg K2O/ha were considered suitable for mondo grass, helping the plant accumulate active ingredients higher than the other treatments.

This study aimed to select new desirable genetic materials in terms of plant growth and shape, size and color of flowers for decorative daylily development program in Vietnam. Sixteen hybrid lines and three cultivars were evaluated. Each genotype was planted with 15 clusters and 2 stems for each cluster. Plant height, number of leaves per stem, flower scape size, number of buds per plant, flower sizewere recorded. All lines/cultivars showed good growth and development in Hanoi’s climate condition. The plant height ranged from 46cm (183-9) to 116.3cm (133-13), scape height was from 38.7cm (193-9) to 110cm (133-5), and flower diameter was from 12.5cm (NB2) to 18.5cm (133-13). Their flower color was grouped into three categories:red, yellow and orange with varried patterns on the flower petals. The flower scape durability last from 7 days (188-1) to 21 days (133-3), resulting in cluster durability ranging from 12 days (NB2) to 31 days (133-3). Based on the growth and development, 12 best lines/cultivars, 193-3, 183-4, 188-1, 133-3, 133-8, 133-10, 133-13, K15, K16, 133-12, NN03, and KC19 were selected.

The study aimed to determine the species composition and abundance of zoobenthos in the paddy fields in Tri Ton district, An Giang province. Zoobenthos samples were collected at 6 sites consisting of 3 sites in the rice field area with 2 crops/year (TV1) and 3 sites in the rice field area with 3 crops/year (TV2) within 4 months. The sampling period began in December 2020, March 2021, November 2021 and February 2022. The results showed a total of 11 species belonging to 9 genera, 7 families, 6 orders, 4 classes and 3 phylums. The number of species in the sampling sites varied from 2 to 7 with a density ranged from 7 to 1,283 ind/m2. The number of benthic species in TV1 was higher than that in TV2. In contrast, the density of zoobenthos in TV1 was 7 times lower compared to that in TV2. The average d and J' indices ranged from 0.4-0.9 and 0.5-0.8, respectively, indicating high diversity and uniformity of benthic density in TV1 and TV2. Shannon diversity index (H') ranged from 0.2 to 1.7, indicating that the zoobenthos diversity richness found in TV1 and TV2 was from low to moderate. The results showed that different rice farming activities affect the distribution of species composition and abundance of benthic organisms in the rice field area at Tri Ton district, An Giang province.

The study aimed to assess the current situation and propose solutions for effective land use management in new rural construction in the Tho Xuan district. The research used the following methods: primary and secondary survey,evaluation according to Likert's 5-level scale, and assessment according to land use criteria. Using the random sampling method, 100 officers were selected for the survey. Regarding the implementation of land use planning, there were 9/30 land use indicators achieved at a very good level, 5/30 of them were good, 3/30 were at an average level, and 13/30 indicators were poor and very poor. Regarding land use management, 2/12 criteria were evaluated as very good; 7/12 criteria were rated as good; there were 2/12 criteria rated at an average level, and 01 criteria rated at poor level.Some solutions were proposed to improve the efficiency of land use management in new rural construction. To improve the efficiency of land use management, it is necessary to strengthen the unity and coherence of planning; monitor rigidly the implementation of the planning; build a master land database; plan and classify land use projects, strengthen propaganda and dissemination; and increase access to land.

The aim of this study was to determine the appropriate dosageand N:P:K ratioof fertilizer for Dien pomeloduring the production cycle on Acrisolsin Chuong Mydistrict, HaNoi. Ten experiments with different formulaswereconducted in2 years on 20-year-old Dien pomelo orchard. The efficiency of fertilizer was determined on the basis yield, quality and economic efficiency. The results showedthat the two formulas withthe highest yield and quality of pomelo were CT4formula(30kg Manure + 0.6kg N + 0.4kg P2O5+ 0.54kg K2O)/tree/year, with NPK ratio of 1:0.65:0.90 and CT6formula(30kg Manure + 0.75kg N + 0.38kg P2O5+ 0.56kg K2O)/tree/year,withNPK ratio of 1:0.50:0.75. The net yield in CT4 formula was28,425 (in 2020)and28,536 (in 2021) fruit/ha and in CT6formulawas28,074 (in 2020)and28,326 (in 2021) fruits/ha (average increase in 2 yearsfor CT4 and CT6 formula was 38.8% and 35.9%, respectively compared to that of the control). CT4 and CT6 formula also gave the best fruit quality with an average fruit height of 11.75cmand11.73cm,and averagefruit diameter of 13.74cm;averagedry matter content of 11.41%and 10.65%;average vitamin Ccontentof 80.0mg%and 73.1mg% and average Brix level of11.15%and 10.93%. In bothyears,2020 and 2021, CT4 yieldedthe highest economic efficiencywiththe averageprofit ofVND427.16 million/ha/year.

The aim of the study was to investigate the effect of 1-MCP on fruit quality of ‘Savior’ tomato grown in summer (off-season) during postharvest storage. Tomatoes at mature green stage wereharvested,treated with 1-MCP at 5 µl.l-1at 18C for 24h, and then stored at 18C. The results showed that the degreening, softening, and the respiration rate were retarded in 1-MCP treated tomatoes compared to the control fruit. Furthermore, 1-MCP increased the acidity of the fruit. Theeffect of 1-MCP as ripening retardant at a concentration of 5 µl.l-1can be applied for post-harvest preservation of summer-grown 'Savior' tomatoes.

The present study was aimed to enhance the antimicrobial activity of Pec-Alg film-forming solution. Nanobubbles (NBs), cinnamon essential oil (Cinna) and chlorine (Chlo) were three potential substances added to Pec-Alg solutions. The microbial inhibitory effect was evaluated in vitro, and the Pec-Alg solutions were directly applied to passion fruits to evaluate the antimicrobial effect, the rate of disease transmission during storage, and the quality changes of passion fruit through physiological, mechanical and biochemical parameters. The results showed that the solutions of Pec-Alg supplemented with NBs or Cinna or Chlo all had high inhibitory effect in vitro conditions with 86.7%, 74.1% and 93.6%, respectively. Moreover, they had a positive inhibitory effect on microorganisms on passion fruits in the following order: Pec-Alg-Chlo > Pec-Alg-NBs > Pec-Alg-Cinna, of which Pec-Alg-Chlo solution had the highest inhibitory effect, reaching 84.4% at 1 hour after coating and 43.6% after 30 days of storage.They were also significantly effective to limit the rate of disease transmission during storage, contributing to prolong the shelf life of passion fruits up to 33 days, which means an increase of 15 days compared to the control and an increase of 9 days compared to Pec-Alg coating without addition ofany antimicrobial agents.

Love grass, Chrysopogon aciculatus(Retz.) Trin., is a perennial grass of the family Poaceae. In this study, the allelopathic potential of this grass was evaluated in different screening conditions. In bioassay, the seedlings of barnyardgrass, rice and mung bean were significantly inhibited at the concentration of 50 g/l of love grass powder;the average inhibition was 56.86%, 52.61% and 46.24%, respectively. Especially, the root growth of the indicator plants was remarkably suppressed. In net house conditions, the germination rate and shoot length of barnyardgrass were inhibited compared with the control treatments. Application of 200 g/m2of the lovegrass powder, the average inhibition was the highest by 42.14%. In the field trial condition, the biomass (fresh weight and dry weight) of barnyardgrass was significantly suppressed which was similar to the net house condition. The highest average inhibition was 37.6%. Moreover, applying 200 g/m2of C. aciculatuspowder reduced the biomass of weeds and simultaneously increased rice yield compared with the control.

Opportunities and challenges recently emerging from the context of digital transformation, urbanization, climate change and globoalization have changed remarkably the role and position of the agriculture, rural economy and farmers. Based on the analysis of recent domestic and foreign studies, the authors clarified the impacts of each context on the sustainable development of the agriculture, rural economy and farmers. Digital transformation is considered as one of the priorities, as a solution to shorten the asymmetric information gap between actors in the value chain of agricultural products. Urbanization contributes significantly to changing the face of rural areas, but also causes socio-economic consequences and disturbances. Climate change is one of the bigest challenges threatening productivity, output of the agricultural sector and income of farmers. In particular, globalization is urging dramatically changes in agricultural production resulting from the demand growth in the world market for agricultural products. Thus, the authors believe that for sustainable development, it is imperative to implement four group solutions synchronously: support to promote digital transformation, take advantage of opportunities from urbanization, adapt to climate change and master the dynamicsof the globalization process.

Bacteriocins produced bybacteria are ribosomally synthesized peptides or proteins with antimicrobial activity that either kill or inhibit the growth of closely-related or non-related bacterial strains. Bacteriocins appear to be a weapon against microorganisms due to their specific properties of natural origin, high structural and functional diversity and heat stability. Recent studies have identified bacteriocins for application in food technology as natural bio-preservatives or in agriculture as biological control agents. Bacteriocins also present a potential approach for the treatment of pathogenic microbial infections and cancer diseases in humans and a promising alternative for replacing conventional antibiotics to treat multidrug-resistant bacteria. However, the majority of application-oriented studies were mainly conducted in laboratory conditions and focused on bacteriocins from Gram-positive bacteria. In this review, we summarized the classification and antibacterial activities of bacteriocins as well as discussed current achievements and potential applications of bacteriocins in the food preservationand inagricultural and pharmaceutical fields. Our paper provides an overview of bacteriocins, thus, orients the application of bacteriocins in Vietnam.