Search

Search Results

• Effects of Housing Systems on Cortisol Concentration of The Gilfs Raised in Group

  Nguyen Thi Phuong Giang, Han Quang Hanh, Vu Tien Viet Dung, Pham Kim Dang, Vu Dinh Ton

  Received: 14-11-2016 / Accepted: 05-01-2017

   Abstract PDF (VIETNAMESE)

  The study was conducted to determine the effects of two housing systems on cortisol concentration of gilts. A total of 20 gilts F1 (Landrace x Yorkshire) gilts with similar body weight and age were randomly allotted into four pens of two group-housing systems (two pens with outdoor yards and the other two without yards, 5 gilts per pen). Saliva cortisol concentration on the days 1, 3, 7, 15, 30, 50, and 80 and plasma cortisol concentration on the days 1, 3, 15, 30,and50 of the gilts after grouping wasere determined by ELISA test and ECLIA (Electrochemiluminescence Immunoassay) using COBAS system, respectively. Results showed that there were no significant differencesin saliva and plasma cortisol concentration of the gilts between the two housing systems (P > 0.05). However, in each housing system, saliva cortisol concentrations on the days of grouping were significantly different (P < 0.05). Cortisol concentration of the gilts in both two housing systems waserehighest on the 1stday after grouping (0.58 µg/ dL in the pens with yard and 0.59 µg/ dL in ones without yard),; they weregradually decreased on the 3rdday (0.48 µg/ dL and 0.46 µg/ dL)and; then theywaserelowest and stable on the following days. Similarly, in each housing system, plasma cortisol concentration taken in the days 1, 3, 15, 30 and 50 after grouping were wassignificantly different from each other (P < 0.05). Plasma cortisol concentration waserehighest in the 1stday after mixing (7.38 µg/ dL in the pens with outdoor yard and 7.17 µg/ dL in the indoor pens), followed by the 3rdday (5.35 µg/ dL and 5.19 µg/ dL), then they were gradually decreased and stable in the following days. A positive correlation between plasma and saliva cortisol concentration was found (withr = 0.73).

• Effects of Housing Systems on Welfare of Gilts and Gestation Sows

  Nguyen Thi Phuong Giang, Han Quang Hanh, Pham Kim Dang, Vu Tien Viet Dung, Chetana Mirle, Vu Dinh Ton

  Received: 01-07-2017 / Accepted: 09-08-2017

   Abstract PDF (VIETNAMESE)

  An experiment was undertaken to assess the effects of housing system on welfare in gilts and gestation sows. The experiment was a factorial design with 20 F1 gilts (Landrace x Yorkshire) of similar body weight and age randomly allocated to two housing systems (group rearing vs. invidual rearing, 5 gilts per pen, two pens for each housing system). Welfare assessment was conducted at a fixed day every week in all 3 stages: gilt, from mating to 30 days, and from 31 to 100 gestation days according to recommendations of the Welfare quality® 2009 Protocol. The results showed that at the gilt stage, housing system significantly affected some criteria of animal welfare in gilts, suchs as percentage of feaces on the body, body wound, stereotypies, and exploratory behaviour. At the stage from mating to 30 days, howver, no influence of housing system on all parameters of animal welfare was observed. At the gestation stage from 31 to 100 days, housing system affected several parameters of animal welfare, including shoulder sores, lameness, percentage of feaces on the body, body wound, stereotypies, and exploratory behaviour. Raising sows under group rearing housing system helped to improve some parameters of animal welfare, health and behaviour. However, it was necessary to have solution to reduce aggressive behaviour among sows during initial days of grouping.

• An Assessment of One Commune-One Product (OCOP) Programme Implementationin Binh Lieu District, Quang Ninh Province

  Nguyen Van Duc, Nguyen Mau Dung

  Received: 10-02-2020 / Accepted: 12-03-2020

   Abstract PDF (VIETNAMESE)

  This study aims to assess the implementation of one commune - one product (OCOP) programme in Binh Lieu district, Quang Ninh province. The main analytical methods used in this study include the descriptive statistics and comparative analysis. The study results show that up to the end of 2019, there are 11 units that have participated the programme with 26 products of good brands, professional styles and compliance with national standards. However, the implementation of the programme still face with several limits of its organizational system, establishing the raw material supply area in the district, business management capacity of units participating OCOP programme, and OCOP product market development. The major measures implicated for enhancing the implementation of OCOP program me in Binh Lieu District include the improvement of the organizational system for OCOP programme, enhancement of proganda and dissemination for raising people’s awareness on OCOP program, capacity building for units participating OCOP programme, and promoting the OCOP product market development in the coming time.

• Characterization of Ground-beetle Community Structure and Identification of ground-beetle Species as Bioindicators for Land use typesat Huu Lien Nature Reserve, Lang Son Province

  Bui Van Bac, Le Minh Thu

  Received: 07-10-2020 / Accepted: 29-01-2021

   Abstract PDF (VIETNAMESE)

  This study examined the differences in species composition and community structure of ground beetles among land use types of karst ecosystems in Huu Lien Nature Reserve (Lang Son Province). Pitfall traps were used to collect ground beetles. In total, 80 pitfall traps were established and distributed in four major types of land use comprising agricultural land, grassland, Acaciaplantations (10 years) and secondary forest (15 years). The study recorded 24 morphospecies of ground beetles from 477 trapped individuals. Agricultural land (maize field) had the highest abundance and species richness and a high level of diversity of ground beetles. The community structure of ground beetles significantly differed among the land uses. Particularly, the species ordination NMDS obviously separated the agricultural ground beetles from the forest communities. The litter layer significantly affected the community structure of ground beetles. The study found four ground-beetle species as bio-indicator species of the agricultural land based on the indicator value (IndVal), including: Pheropsophus jessoensis Morawitz, 1862, Chlaenius pleuroderusChaudoir, 1883, Harpalus indicusBates, 1891 and Chlaenius flavofemoratusLaporte, 1834.

• Growth Performance and SemenQuality of the Stress Negative Piétrain BoarsRaised at the Animal Farm of Hanoi University of Agriculture

  Ha Xuan Bo, Do Duc Luc, Bui Van Dinh, Bui Huu Doan, Vu Dinh Ton, Dang Vu Binh

  Received: 30-01-2013 / Accepted: 23-04-2013

   Abstract PDF (VIETNAMESE)

  This study was carried out on 10 stress-negative Piétrain boars including 3 pigs of halothane genotype CC and 7 of CT at the pig breeding farm of Hanoi University of Agriculture in order to evaluate effects of season (Spring, Summer and Autumn) and halothane genotype (CC and CT) on the production performance and semen traits. The results showed that the difference in daily average gain was not significant between CC (559.57 g/day) and CT boars (546.31 g/day). The halothane genotype did not affect semen traits (P>0.05) except ejaculation volume (P<0.001). Ejaculation volume of CC genotype (270.95ml) was higher than that of CT (220.82ml). Season had significant effect on ejaculation volume, sperm concentration and pH of semen (P<0.001) as well as total number of sperms moving straight ahead per each ejaculation (P<0.05). Semen volume was highest in autumn (293.02 ml) followed by summer (195.00 ml) and spring (190.86 ml) while this tendency was inverse for sperm concentration. Total number of sperms moving straight ahead per each ejaculation was highest in autumn (47.15 billion) followed by spring (45.20 billion) and lowest in summer (36.74 billion). Semen traits of the stress-negative Piétrain boars were in accordance to the standards of technical criteria for animal breeding accoprding to the Decision No. 1712/QĐ-BNN-CN (Ministry of Agriculture and Rural development, Vietnam), except sperm motility and growth performance were lower than specified.

• Program to analyze Lattice Design

  NguyenDinhHien

  Received: 13-12-2013 / Accepted: 26-02-2014

   Abstract PDF (VIETNAMESE)

  Program Lattice for partially balanced lattice design was written in 1999. In this paper wecompare results analyzedby program Lattice and and found that the results are fit in Lattice Program given by SAS 9.1

• Assessment of Genetic Diversity on Fruit Traits of Cherry Tomato Germplasm Based on Images

  Nguyen Trung Duc, Nguyen Thi Nguyet Anh, Pham Quang Tuan, Vu Thi Thuong, Nguyen Viet Linh, Bui Thi Thuy, Vu Van Liet

  Received: 30-08-2022 / Accepted: 18-04-2023

   Abstract PDF (VIETNAMESE)

  This study aimed to assess the fruit trait diversity of cherry tomato germplasm through image-based phenotyping for the nutritious cherry tomato breeding program in Vietnam. Fruit images of sixty-eight cherry tomato accessions grown in winter crop season 2021 at the Vietnam National University of Agriculture were collected at the harvest stage and then were analyzed by SmartGrain software. Comparing the accuracy with the manual measurement using a simple linear regression model, the obtained results show that the fruit length and width extracted from the image had a high determination coefficient (0.81 and 0.76, respectively) and low root mean square error (2.95 and 2.35, respectively) compared with manual measurements. The image-extracted fruit traits were more closely and positively correlated with fruit weight as compared to manual measurements. The tomato germplasm were classified into 6 groups at the similarity coefficient of 65.95 from 5 image-extracted fruit traits. Fruit image-based phenotyping can replace the manual measurement and apply in tomato breeding, testing system, and further apply to other cultivars.

• Effect of Potassium Application on Development, Yield of Mungbean in the Coastal Sandy Soil in Nghe An

  Phan Thi Thu Hien, Nguyen Dinh Vinh, Pham Van Chuong

  Received: 09-10-2015 / Accepted: 10-03-2016

   Abstract PDF (VIETNAMESE)

  The study was carried out to determine the optimal level of potassium for growth and grain yield of three mungbean varieties (ĐX22, ĐX208, ĐX16) in coastal sandy soils ofNghe An province. The experiment was conducted in 2013 and 2014 Summer - Autumn seasons ina split - plot with and 3 replicationswherein mungbean varieties being the main plot factor and levels of potassium (0, 30, 60 and 90 kg K2O/ha) combined with 30 kg N/ha - 60 kg P2O5/ha) the subplot factor. The results showed that 60 kg K2O/ha combined with 30 kg N/ha and 60 kg P2O5/ha increased grain yield of mungbean varieties by 29,1-42,4% in comparison withoutpotasium application. This rate of potassium can be recommended for mungbean cultivation in coastal sandy soilsinNghe An.

• Evaluation and Screening of Maize Inbred Lines for Drought Tolerance Based on Phenotype and Molecular Markers

  Nguyen Thi Han, Dong Huy Binh, Nguyen Van Giang, Vu Van Liet, Nguyen Quang Tuan, Vu Thi Bich Hanh

  Received: 22-03-2016 / Accepted: 22-06-2016

   Abstract PDF (VIETNAMESE)

  Drought is one among the major abiotic stress factors severely limits maize grain yield production. Improving drought tolerance in maize has become one of the top priorities in maize breeding programs. Thirty two maize inbred lines and two check varieties were evaluated under field conditions and screened for drought tolerance under water stress conditions in the greenhouse. For drought evaluation, the first experiment was carried out using plastic pots exposed to drouhgt stress conditions. In the second experimen, thirty two inbred lines were planted at four planting dates startng from 2 March and successive planting after very ten days, in soil bed conditions and drought was imposed when plants of the first planting were at dough stage and the plants of other plantingss were at tassel and silking stage, at 12 collars stage and at 6 collars stage. Eleven and 14 inbred lines were identified as drought tolerant in pots experiment and in greenhouse soil bed, respectively. With the use of molecular marker, 20 inbred lines containing QTL related to drought tolerance were identified. Combining phenotypic evaluation and molecular markers, 11 inbred lines possessed desirable characters and drought tolerance, i.e. H4, H6, H14, H15, H17, H20, H23, H24, H28, H29 and H30. Drought tolerant inbred lines identified in this study can be utilized for future breeding programme.

• Assessment of IBDV Antibody Titer and Productivity of Commercial Broiler Chicken at Field Trial Post-Vaccination with Tabic MB and IBDV-Icx

  Le Thi Kim Tuyen, Nguyen Thi Kieu Oanh, Nguyen Manh Ho, Nguyen Thi Van Anh, Quach Tuyet Anh

  Received: 27-07-2023 / Accepted: 05-01-2024

   Abstract PDF (VIETNAMESE)

  The study was conducted to evaluate antibody titers against IBDV and the productivity of commercial broiler flocks at field trial vaccinated with live vaccine Tabic MB and immune complex vaccine (IBDV-Icx). A total of 240 blood samples were randomly collected from 2 farms to test antibody titers against IBDV by ELISA technique. Mean body weight, average daily weight gain, and FCR were monitored until slaughter. The results showed that the chickens had high level of maternally derived antibodies (MDA). At 3 days old, the mean MDA was 5,582 titer units. At 30 days old, the number of positive samples with anti-IBDV (> 396 titers) in the group using Tabic MB and IBDV-Icx vaccines was 20% and 5%, respectively (P <0.05). Especially at 35 days of age, the titer at farm using the Tabic MB vaccine was 2,671 , which was significantly higher than that of the farm using the IBD-Icx vaccine, with titer of 132 only (P <0.05). Chicken body weight and average daily weight gain of this survey were similar (P >0.05). However, the FCR of chickens using Tabic MB vaccine was lower than chickens using IBDV-Icx vaccine (P <0.05). Briefly, commercial broiler chickens using Tabic MB vaccine had higher antibody titer against IBDV and productivity parameters were not affected compared with vaccinated with IBDV-Icx .

• Analysis of Genetic Diversity Based on Phenotypes and SSR Markers and Evaluationof Drought Tolerance of Waxy Maize Inbred Lines for Developing Hybrid Varieties for Northern Moutainous Provinces

  Le Thi Minh Thao, Nguyen Thi Anh, Tran Thanh Tan, Pham Quang Tuan, Vu Van Liet

  Received: 24-02-2014 / Accepted: 10-06-2014

   Abstract PDF (VIETNAMESE)

  Assessing genetic diversity and heterotic grouping of 24 waxy maize inbred lines in S8 to S10 generations were performed using morphological characters and molecular markers (SSR). The field experiment was designed to identify the agronomical characteristics, namely growth duration, plant height, anthesis-silking interval, yield and yield components. Results showed that the maize inbred lines possessed agronomic characters suitable to develop single crosses. Based on genetic diversity analysis of morphometric traits, 24 inbred lines were grouped into six heterotic groups at similarity value of 0.25. Genetic diversity analysis of inbred lines by 19 SSR markers detected 19 loci with a total of 75 alleles and average of 4 alleles per locus. Polymorphic Information Content (PIC) varied from 0.36 to 0.81. At genetic similarity value of 0.83, 24 inbred lines were divided into five groups. Of 24 lines tested, 5 lines, viz. I5, I9, I8, I23, I15 were identified to be drought tolerant. These lines belonged to the different heterotic groups and therefore they can be used for hybrid waxy maize breeding for drought prone environment such as rainfed farming condition for northern moutainous provinces.

• Effect of Inorganic N, P, K Conbination on Growth, Yield and Quality of Sweet Potato in Thai Nguyen

  Nguyen Thi Lan

  Received: 20-02-2017 / Accepted: 19-06-2017

   Abstract PDF (VIETNAMESE)

  In order to determine an optimal N, P, K combination for improvingyield, quality and economic efficiency of sweet potato production, an experiment was conducted with 5 inorganic N, P, K combinations. Arandomized complete block design with 3 replications was carried out in spring and winter seasons in Thai Nguyen. The result showed that increased rate of N, P, K lengthened theduration of tuber formation and growth whilst reduced duration ofcanopycover. Increments of N, P, Kalso increased main vinelength, average tuber weight, top growthyield, and harvested root yield.. For spring and winter seasons,the optimum rate was recommended at 70 N + 70 P2O5+ 100 K2O because it gave the highest average tuber weight, harversted yield and profit (50.434.800 VND/ha in srping season and 40.301.200 VND/ha in winter season).

• Effect of Granular Nitrogen Fertlizer on Growth, Development and Performance of Hybrid Maize cv. C919

  Tran Duc Thien, Nguyen The Hung, Nguyen Tat Canh

  Received: 23-05-2014 / Accepted: 22-07-2014

   Abstract PDF (VIETNAMESE)

  The effect granular or slow-release nitrogen fertilizer ongrowth, development and yield of C919 hybrid maize was studied in Winter 2011 and Spring 2012, in Vinh Loc district, Thanh Hoa province. The experiment consistedof seven application levels per hectare (T1: 0kgN; T 2: 90kgN; T 3: 120kgN; T 4: 150kgN; T 5: 180kgN; T 6: 210kgN and T 7: 150kgN). The experiment was arranged in a randomized complete block design (RCBD) with three replications, 14 m2plot size, and planting density of 59,000/ha. The experiment plots were applied with 8 tons of manure, 90 P2O5and 90 K2O/ha. The study results showed that the use of slow-release nitrogen fertilizer exerted positive effect on growth, development and yield of corn. With application levels from 120kgN to 210 kgN/ha corn yields varried from 7.046 ton/ha to 7.813 ton/ha; higher than ureaapplicationfrom 16.9 - 21.7%. Application of slow-release nitrogen fertilizer increased nitrogen use efficiency (NUE) as compared withurea. It was suggested that forcultivation of C919maize in the study area,slow-release nitrogen fertilizer be applied with the rate of 120 kgN/ha plus the 8 tons of manure, 90kg P2O5and 90kg K2O.

• Identification of SSR Markers Linked to sh2and su1Genes in Sweetcorn Lines

  Nguyen Trung Duc, Nguyen Quoc Trung, Pham Quang Tuan, Nguyen Thi Nguyet Anh, Pham Thu Hang, Pham Xuan Hoi, Vu Van Liet

  Received: 09-08-2022 / Accepted: 02-03-2023

   Abstract PDF (VIETNAMESE)

  The objectives of this study were to identify SSRmarkers closely associated with shrunken2 (sh2)andsugary1 (su1) genesandapplication forselecting target genotypes on 30 S3 sweet corn lines. Four SSR markers closely associated with the sh2gene (umc1320, umc2276, umc1273, bnlg1257) and four SSR markers closely associated with the su1gene (umc1142, umc1031, bnlg1937, umc2061) were investigated in three check lines. The results showed that the markers umc2276 and umc1031 were suitable to identify the sh2and su1genes, respectively. Using these markers for screeningon 30 S3 sweet corn lines identified 7 lines homozygous for recessive gene sh2sh2(D04, D09, D13, D21, D22, D24, D25), 2 lines homozygous for recessive gene su1su1(D19, D30) and 2 lines double homozygous recessive for sh2sh2su1su1(D11, D14). Phenotypic evaluation confirmed the similarity to genotypes and proved high accuracy of the selected molecular markers. Total soluble solids of the sh2sh2su1su1lines were higher than sh2sh2lines and superior to that of the su1su1lines. These SSR markers and 11 selected genotypes played a vital role for the rapid development of high-quality inbred lines for specialty corn hybrid breeding in Vietnam.

• Selection and General Combining Ability Evaluation of the Sweet Corn Inbred Lines

  Tran Thi Thanh Ha, Vu Van Liet, Vu Thi Bich Hanh, Nguyen Van Ha, Duong Thi Loan, Hoang Thi Thuy

  Received: 11-02-2020 / Accepted: 22-09-2020

   Abstract PDF (VIETNAMESE)

  This study was to perform selection and assessment of general combining ability of the sweet corn inbred lines to select the combination of yield and quality to serve the production of high-yield and quality sweet maize varieties for Vietnam market. The genetic diversity of 32 S4-S6 self-combining sweet corn lines originating from China, USA, Thailand, Philippines, Taiwan was assessed based on the phenotype in Spring 2018 conditions using NTSYS software and identified 31 groups/32 lines at the difference of 29%. Selection of elite lines was made based on the Oclit distance biological statistics program with phenotypic traits selected 8 lines (D6, D7, D15, D21, D26, D28, D31, D32). These sweet maize lines have had a short to medium day growing time (104-111 days), average tree height (94.75-134.88cm), individual productivity reaches from 15.91 to 23.03 grams, Brix degree reached over 13%. These eight lines were introduced to the top cross with two tested corn plants in the Winter of 2018 and determined the combined ability (GCA) of 8 lines based on 16 hybrid combinations using genetic software. In the Spring crop of 2019, two lines D26 and D31 were identified that have had the high combined ability for productivity and quality for breeding, high-yield and quality sweet corn varieties.

• Effect of Fertilizer on Growth Development and Yield of Autum Groudnut at Hoang Hoa-Thanh Hoa

  Vu Dinh Chinh, Tran Thi Nien

  Received: 26-08-2012 / Accepted: 16-11-2012

   Abstract PDF (VIETNAMESE)

  The effect of fertilizer dose on growth, development and yield of two groundnut varieties L14 and TB25 in Autumn growing season was studied in Hoang Hoa, Thanh Hoa. The experiment was replicated three times in a split plot design. The results showed that fertilizer influences on growth, development and yield. Fertilizer influences on duration, branch, leaf area index, dry matter accumulation, number of nodes, number of pods and grain yield. Optimum fertilizer dose for both two groudnut varieties L14 and TB25 at Hoang Hoa-Thanh Hoa is 30kgN+90kgP2O5+ 60kgK2O/1ha.

• Effect of fertilizer and pruning on the yield and quality of raw materials for processing Oolong tea in Phu Tho

  Hoang Thi Le Thu, Nguyen Dinh Vinh, Do Van Ngoc

  Received: 12-06-2013 / Accepted: 24-08-2013

   Abstract PDF (VIETNAMESE)

  A study was carried out toexamine the effect of differentfertilizerformulationsandpruningtypesongrowth, yieldandqualityof raw materialsfortheprocessing ofOolongtea. Cv. Kim Tuyên Theexperimentwasarranged in a split-plot design with triplicates. Results indicated that application of 15tonsfarmyard manure plus 5tonschicken manure and medium, pruning 55cm above ground yielded bestqualityof raw material and Oolongtea product.

• Potential Assessment of Biodiversity Potential and Forest Environmental Services for Payment Environmental Services Paymentin Ba Be District, Bac Kan Province

  Cao Truong Son, Nguyen Thanh Lam, Tran Duc Vien

  Received: 21-07-2016 / Accepted: 20-12-2016

   Abstract PDF (VIETNAMESE)

  This study was carried out to assess biodiversity and environmental services for inplementing payment environmental servicespaymentof Ba Bedistrict, Bac Kanprovince. Keyinformant and household interviewds were two main methods whichwere used to collect information. Results showed that the fauna and flora of Ba Beweare diverseifiedwith many species belonging to the listed in the rRed bBook of Vietnam and of the world. In additon, Ba Behas two main forest ecosystems which distributed in different terrains. As a result, forest of Ba Beproduceddiversified environmental services with high value. However, forest and biodiversity conservation activities of Ba Bedistrict did werenot encouragedpromotebecause the environmental services were exploited and implementedusedineffectively. Hence, in the next time Ba Bedistrict should implement forest and diversity conservations more effectively for maintaning environmental services supply ability of forest ecosystems and promotingeto implement payments for environmental services programs to protect forest resource and improve income for local people.

• Genetic Diversity Analysis of 10 Oyster Mushrooms (Pleurotusspp.) Accessions by RAPD and ISSR Markers

  Dinh Truong Son, Nguyen Thi Ngoc Anh, Nguyen Thu Hang, Nguyen Thi Bich Thuy, Nong Thi Hue, Ngo Xuan Nghien

  Received: 15-08-2023 / Accepted: 25-12-2023

   Abstract PDF (VIETNAMESE)

  Oyster mushrooms (Pleurotusspp.) are widely consumed in the world due to their delicious taste, high nutritional value and medicinal properties. For breeding program to develop new cultivars, besides phenotypic characteristics genetic characterization of the material is important since it helps breeders to choose suitable materials for hybridization. This study analyzed the genetic diversity of 10 oyster mushroom accessions using 20 RAPD markers and 17 ISSR markers to provide information for oyster mushroom breeding programs. The markers amplified a total of 560 loci with 552 polymorphic loci and 2,138 PCR product bands. When combining both RAPD and ISSR markers, the genetic similarity coefficient of 10 oyster accessions ranged from 0.459 to 0.755. At the average genetic similarity coefficient of 0.579, 10 oyster mushroom accessions were divided into 3 main groups. These results indicate that 10 collected oyster mushroom accessions had a high level of genetic diversity and can be used for new oyster mushrooms breeding program.

• Effects of Substrate on Growth and Yield of Mustard Greens,Pak Choi and Mustard Grown in Circulating Hydroponic System in Greenhouse

  Son Thi Thanh Nga, Nguyen Hong Ung, Ngo Thanh Trac

  Received: 26-12-2022 / Accepted: 20-11-2023

   Abstract PDF (VIETNAMESE)

  Experiments were conducted to determine the suitable substrate for the growth and development of 3 cultivars grown using circulating hydroponic system. The study was conducted in 2020 in hydroponic vegetable house of the Faculty of Agriculture and Fisheries, Tra Vinh University.The experiment was arranged in a completely randomized fashion consisting of 5 experiments and 5 repetitions. The substrates used for the experiment consisted of coconut coir and cow manure that were composted for 8 months and mixed in different proportions, and the foam was used as a control. Vegetables grown included mustard greens (Brassica juncea L.), Pak choi (Brassica chinensis L.) and mustard (Brasica juncea L.). Data recorded included the number of leaves, plant height, stem and root weight, and yield. The results showed that substrate mixture of 75% coconut coir + 50% manure used in circulating hydroponic system gave highly significant effect on plant growth, such as, plant height and leaf number and finally yield and net profit.

• Effects of Stocking Density on Growth Performanceand Body Surface Temperature in Broilers

  Che Minh Tung, Nguyen Thi My Nhan

  Received: 17-04-2023 / Accepted: 29-08-2023

   Abstract PDF (VIETNAMESE)

  The objective of this study was to evaluate effect of stocking density on growth performance and surface temperature of different body parts in broilers. A total of 1000 one-day-old broiler chicks (Ross 308) were assigned to two treatments in a completely randomized design. The stocking density treaments were (1) 9 chicks/m2(SD 9) and (2) 13 chicks/m2(SD 13). Each treatment had 20 replicate pens (50% female and 50% male/pen). The experimental results showed that there was no difference in average daily weight gain between two treatments (P >0.05). However, broilers in the SD 9 group had a better feed conversion ratio than those in the SD 13 group (P = 0.048). The survival rate of broilers in the SD 9 group (99.8%) was greater (P <0.001) than that of broilers in the SD 13 group (95.8%). Moreover, the body surface temperature of broilers in the SD 9 group (32,3C) was much lower (P = 0.003) than that of broilers in the SD 13 group (36.0C). A similar trend was also observed for the shank and neck surface temperature of broilers (P <0.05). Briefly, the stocking density of 9 broilers/m2improved the feed conversion ratio, survival rate and body surface temperature of broilers as compared with the stocking density of 13 broilers/m2.

• Laminated Composite Plate Reinforced by Carbon Nanotube: Free Vibration Analysis using Four-variable High order Plate Theory

  Duong Thanh Huan, Vu Van Tham

  Received: 26-04-2021 / Accepted: 18-05-2021

   Abstract PDF (VIETNAMESE)

  In this paper, a four-variable refined plate theory (HSDT4) was used for free vibration analysis of functionally graded carbon nanotube-reinforced laminated composite plates. Equations of motion for simply supported rectangular plates were derived using Hamilton's principle. Comparison studies were carried out to verify accuracy of the present model. New parameter studies regarding the influence of material properties, plate geometry, CNT volume fraction, CNT distribution types, on the natural frequency were performed in detail.

• Effects of Planting Density and Fertilizer Level on Growth, Development andProductivity of Honeysuckle (LonicerajaponicaThunb.) at Thanh Tri - Ha Noi

  Ninh Thi Phip, Do Thi Be

  Received: 26-04-2018 / Accepted: 09-10-2018

   Abstract PDF (VIETNAMESE)

  The present studywas to determineeffects of planting densityandlevel of NPK fertilizer on plant growth, productivity and medicinal quality and economic efficiency of honeysuckle (Lonicera JaponicaThunb.) in Thanh Tri -Ha Noi were studied. The experiment was designed according to a split-plot design with 3 replicationsat three NPK levels (P1, P2, P3)and four planting densities (M1, M2, M3, M4). The results showed that the plant growth, yield andmedicinalquality were influenced by planting density and the level of fertilizer. The plant grown at M2 (27,800 plants/ha, 60x60 cm) and fertilized withP3 (20 tons farmyard manure + 120 kg N/ha + 90 kg P2O5/ha + 120 kg K2O/ha)produced higher yield but lower loganin content compared to the other treatments. Plants grown with P1 (80 kg N/ha + 60 kg P2O5/ha + 80 kg K2O/ha)combined with M2 (27,800 trees/ha, 60x60 cm)produced good yield of medicinal material (34.70 quintals/ha), highest loganin content and highest loganin yiled.

• Genetic Diversity and Combining Ability for Fruit Yield and Quality of Some Muskmelon (Cucumis meloL.) Lines

  Nguyen Thi Nguyet Anh, Pham Quang Tuan, Vu Van Liet, Nguyen Trung Duc, Doan Thi Yen

  Received: 30-05-2018 / Accepted: 21-09-2018

   Abstract PDF (VIETNAMESE)

  This study was carried out to analyze the genetic diversity among 30 muskmelon (Cucumis melo L.) inbred lines belonging to cantaloupensis group (lines numbered from D1 to D22) and reticulatus group (lines numbered from D23 to D30). The inbred lines were developed by selfing exotic germplasms introduced from China, Japan and Israel at the Crop Research and Development Institute, Vietnam National University of Agriculture. The inbred lines were grown in nethouse conditions in the spring season and 31 morphological traits were recorded to identify genetic groups. Genetic diversity analysis based on phenotype showed that 30 melon inbred lines could be grouped into 6 distinct groups with genetic similarity of 0.32. Six superior lines D1, D2, D3, D7, D13, and D20 were selected for diallel cross to evaluate combining ability in 2017 summer-autumn season. Four inbred lines D1, D3, D7, and D20 had high combining ability for yield and total soluble solids (Brix degree). Three promising hybrids THL2 (29.65 t/ha), THL6 (30.23 t/ha), and THL9 (33.17 t/ha) were selected for further study.

• Effect of Placement Distance and Depth of Granular Nitrogen Fertilizer on Growth and Yield of Maize

  Tran Duc Thien, Nguyen The Hung, Nguyen Tat Canh

  Received: 11-03-2015 / Accepted: 09-04-2015

   Abstract PDF (VIETNAMESE)

  Successful nitrogen management supplies enough nitrogen to the crop to optimize performance and profitability while minimizing losses to water and air. The present experiment was conducted to investigate the effect of fertilizer placement distance and depth of granular or slow-release nitrogen on growth and yield of C919 corn hybrid in 2012 winter 2013 spring seasons in Vinh Loc district, Thanh Hoa province. All experimental plots were applied with 8 tons of manure, 120 kgN in granular form, 90 kgP2O5, 90 kgK2O per hectare basis. Twelve treatment combinations of three placement distances and 4 depths of granular nitrogen fertilizer application was arranged in a randomized complete block design with three replications. The results showed the depth and placement distance of slow-release nitrogen fertilizer did not affect growth duration of maize C919 in both growing seasons but leaf area index, dry matter accumulation, yield components and grain yield. Highest grain yield was obtained when slow-release N fertilizer placed at 10 cm from the plant and 10 cm deep in the soil.