Vol. 14 No. 11 (2016)

The purpose of this research was to asses photosynthesis and dry matter accumulation of an extremely early maturing rice line DCG72 under different nitrogen levels in spring cropping season 2015 in the green house at VietNam National University of Agriculture. The pot experiment included three nitrogen levels: no nitrogen application (N0; 0 g N/pot), low nitrogn level (N1; 0.5 g N/pot) and high nitrogen level (N2; 1.5 g N/pot). The results showed that the higher nitrogen level was applied, the higher was number of tillers per cluster in early maturing line DCG72 and the check cultivar, KD18. At dough- ripening stage, photosynthetic intensity in DCG72 was significantly higher than in KD18 at N1 but lower at N2 because of low nitrogen content and chlorophyll in leaf in DCG72. The accumulation of dry weight at post-heading stage and the ratio of dry weight of panicle/cluster in DCG72 were significantly lower than those in KD18 at N2. Individual grain yield was similar between two cultivars at N0 but significantly higher in DCG72 than that in KD18 at N1 because of high number of spikelets per panicle and 1,000-grain weight. However, the grain filling ratio (%) in DCG72 was low so that individual grain yield of DCG72 was significantly lower than that of KD18 at N2.

Adaptability and haploid inducing ability of UH400 were evaluated in 4 cropping seasons during 2014 and 2015 at Gialam, Hanoi, Vietnam. Twenty yellow dent maize hybrids were crossed with UH400 and the F1 seeds were evaluated for haploid induction rate using anthocyanin color marker. Ploidy doubling was done by colchicine treatment at 0.06% for 8 hours to develop double haploid (DH) lines. DH lines were evaluated for growth and yield in 2015 spring cropping season and ploidy level determined in spring 2016. The studies showed that UH400 can be grown in fall-winter and spring cropping seasons in the North of Vietnam, while seed multiplication and line maintenance be done in spring. UH400 can be used for haploid induction on yellow dent maize hybrids with induction rate of 7.05%. DH lines developed in this study had poor survival rate (14.4%). The use of SSR marker phi065 to identify haploid seeds from six crosses with UH400 showed that five crosses (M8, M12, M19, M21 and M22 crossed to UH400) are haploid.

This study was done to determine blood haematological parameters (red blood cell count, hemoglobin, white blood cell count, white blood cell composition, platelet cell count and other platelet parameters) and blood biochemistry (total plasma proteins, serum albumin, globulin and glucose, serum sodium, serum postassium, serum chloride and calcium levels) of water buffaloes raised in Cam Thuy district, Thanh Hoa province. Red blood cell count, hemoglobin values, white blood cell count, platelet cell count, plasma total protein and globulin concentrations were age-dependent. Sex dependences were observed in red cell distribution width but not in white blood cell and platelet values. The determined values were compared with reference values of the International Federation of Clinical Chemistry (IFCC) and results obtained from previous studies. The present results can be employed as reference data for study, diagnosis and treatment of bufalo diseases with widely used automated analyzers for clinical blood parameters.

The study was conducted to evaluate the growth performance, carcass yield and meat quality of Dong Tao chickens raised under semi-pasture at households. Five households in Dong Tao commune were selected for raising 250 Dong Tao chickens from 1 day old to 24 weeks old. The results showed that after 24 weeks, the survival rate was 86.4%. The males and females reached body weight of 2584.76 and 2.188,95g, respectively. The feed intake and FCR were 105 g/head/day and 4.6 kg, respectively. Dressing, breast, thigh and abdominal fat rate were 66.76, 15.39, 23.40 and 1.62%, respectively (the males had no abdominal fat). The meat colors of Dong Tao chicken were as follows L*: 53.71 - 59.72; a*: 8.20 - 13.76 and tenderness ranged between 28.66 - 37.14 kg/cm2. The thigh muscles were darker, dark red and tougher than breast muscles. Dong Tao chickens were relatively high in carcass yield, normal in meat quality and the meat was red and tough.

In this study, we investigated some characteristics of Ornithobacterium rhinotracheale - ORT. Tracheal swabs, lung and airsacculitis were collected from 60 chickens showing clinical signs including loss of condition, gasping respirations and coughing for bacterial isolation and identification. The collected samples were cultured on Columbia Blood Agar Basal medium supplementing with 5% sheep blood or rabbit blood and 5 μg/ml Gentamycin, incubated at 37°C and 5% CO2 for 48 hours. Small colonies were observed with some characteristics such as gray to grayish color, non-hemolysis, gram (-) staining, various lengths and rod shape. 30/60 colonies showed negative results in reaction with Catalase and Indol, but positive results in reaction with Oxidase, and were unable to grow on MacConkey medium. ORT isolates were able to resolve fructose, galactose, glucose, lactose, maltose and urease, but could not resolve sucrose and nitrate. ORT isolated strains were confirmed by PCR, showing approximate 784 bp-length products. The isolates were highly susceptible to amoxicillin/clavulanic acid and ampicillin while they were resistant to erythromycin, gentamycin, enrofloxacin and norfloxacin.

Zooplankton is not only dependent on the trophic state through food chains of algae but also controls nutrient levels through consumtion of algae. The study was conducted with 16 irrigation canals in the district of Gia Lam that had different nutrient levels to prove the relationship. Many of these irrigation canals were contaminated by various waste sources, showing nutritional status from moderate to high level (60-100 points). From January to May (2015), 71 species of zooplankton were identified with Rotifers being dominant both in number of species (39 species) and density (>70%). The diversity index was moderate at medium trophic level (H' was 2.52 at the TSI of 60-80) and lower in high trophic level (H’ was 1.83 at the TSI of 80-100). The species of lower trophic levels (TN<7 mg/l and TP<0.4 mg/l) included Brachionus budapestinensis, Brachionus falcatus, Brachionus forficula, Keratella tropica(Rotifer); Sida crystallina, andCeriodaphnia quadraugula(Cladoceran). The species adaptable to moderate to high trophic included Ceriodaphnia laticaudata, Alona davidi(Cladocerans); Eucyclops serrulatus, and Ectocyclops phaleratus(copepods). They may be the pollution sensitive and pollution resistant species.

The objectives of this study were to determine (i) the efficiency of NPK fertilizers application by site-specific nutrient management (SSNM) on NPK uptake and (ii) the economic efficiency of SSNM for maize on undeposited alluvial soil. The on-farm research was conducted in a completely randomized block design with three farmers’ fields, with three replications in 2014 - 2015 dry season in An Phu - An Giang. The treatments included (i) SSNM (200 N - 90 P2O5 - 80 K2O), (ii) bio-organic fertilizer incoporation with NPK fertilizers application - BOF + NPK (bio-organic fertilizer contains 15% organic matter; the concentration of N - P2O5 - K2O is 1,0 - 1,0 - 1,0 (%), respectively). The density of nitrogen-fixing and phosphorus-solibilizing was 1 x 106 CFU per gram and chemical NPK fertilizers of 138 N - 63 P2O5 - 56 K2O), and (iii) farmers’ practice - FP (236 N - 126 P2O5 - 46 K2O). The results showed that, compared to FP, the SSNM application gave better grain yield, NPK uptake as well as higher net benefit.

By assessing the relationship between the geomorphological process and soil process and comprehensive assessment of natural conditions at the basement of Ba Vi mountainous area, the study has indentified suitable areas for developing red flesh dragon fruit cv. Long Dinh No.1. The obtained results showed that five soil - geomorphology landscape units covering a total area up to 6,645.3 ha are suitable for planting cv. Long Dinh No.1, accounting for 33,32% of the total natural area in Ba Vi district, of which, the most suitable area occupied 5,691 ha (CQ20, CQ22, CQ23, CQ26).

The purpose of this research was to apply micro-biotechnology to treat mushrooms culture wastes to produce organic substrate for safe vegetable production in order to efficiently recycle the organic waste resources and increase the value for mushroom growing towards sustainable agricultural development and environmental protection. Five microbial strains, including Azotobacter, Bacilus subtilis, Sacharomyces, Streptomyces and Trichoderma with high amylase, protease and cellulase and biological activities were used as biological formulation for treating the mushroom culture wastes. Results obtained indicated that the organic substrate after treatment had high nutrient content and high density of useful microorganisms that ensure the growth and development of vegetables without other additional costs. Ceylon spinach grown on organic substrate showed better growth, significant yield increase and reduced insect infestation rate. Moreover, the vegetables grown on the substrate from treatment of mushroom wastes possessed high quality standards for safe vegetables conforming to the Decision No. 106/2007/QD-BNNPTNN.

Currently, many methods such as filtration, centrifugation, flotation, and flocculation for harvesting algae for biofuel production development have been studied. In this study, application of membrane filtration to harvest microalgae was evaluated in a lab-scale system. The working volume of the system was 1 l. A hollow fiber membrane (with the surface of 0.065 m2, pore size of 0.2 µm) was submerged in the system. During the experiment, the air was supplied to prevent the membrane fouling due to the attachment of the micoralgae on the membrane surface. As a result, when the air intensity increased from 0 to 0.315 l/cm2.min, the flux increased and the transmembrane pressure decreased. When the air intensity was lower than 0.189 l/cm2.min, the flux decreased and the transmembrane pressure increased rapidly. When the air intensity was maintained higher than 0.189 l/cm2.min, the flux and the transmembrane pressure were relatively constant. Operational mode of suction pump should be maintained at 5 min on: 5 min off to keep the flux and the transmembrane pressure stable. During opertation, microalgae concentration significantly affected the flux and the transmembrane pressure. In conclusion, membrane filtration could be applied to harvest the microalgae. During operation, the air intensity should be maintained higher than 0.189 L/cm2.min to help the filtration longer. Membrane filtration could be an effective method for harvesting microalgae.

The aims of the present study were to assess soil properties and soil contamination level in Nhue river basin. Forty soil samples and twelf water samples were taken. Results showed that soil pH varied from acidic to light acidic (4.3 - 6.0). Soil organic matter (SOM), total nitrogen, total phosphate and total potasium ranged from moderate to high (SOM: 1.50 - 2.50%; N: 0.08 - 0.20%; P2O5: 0.01 - 0.14%; K2O: 1.48 - 1.80%). The quantity and composition of microorganisms were diffrent between paddy soil and others. Total anaerobic bacteria were highest in paddy soil (8.2x106 CFU.g-1), 2.2 times of vegetable soil. Total fungi were variable with soil pH except actinomycetes. Analysis of irrigation water showed that 50% samples had pH exceeding the limit justified by QCVN 08:2008/BTNMT. TSS was high and very close to the limit. Some water samples showed that heavy metals (Pb, Cd, Cu, Zn ) were around concentration threshhold. Farmland in the study area showed sign of heavy metal contamintion. Concentration of copper in two soil samples (DTS02 and DTS03) in Bach Thuong commune was exceeding the limit (55.28 mg.kg-1 and 55.03 mg.kg-1, respectively). Concentration of heavy metals in paddy soil was higher than that in vegetable soil.

An experiment was conducted to screen and identify the actinomycete trains that are capable of antagonizing Vibrio parahaemolyticuscausing disease on shrimp. Among of 96 isolated strains, three strains were obtained as capable of antagonizing Vibrio parahaemolyticusby agar diffusion plate method. The strain number 25.2 had strongest activity with a diameter of 15 mm clear zone of bacteria. The 25.2 strain showed white colonies but white colonies with grey borders after three and seven days of incubation, respectively. The strain did not produce soluble pigments on Gause-1 medium but grew well at temperatures between 30 - 45°C and neutral pH, and was tolerant to high salt concentration medium. The 25.2 strain was able to utilize several sources of carbon and nitrogen. Results of 16S rRNA sequence analysis showed that the strain 25.2 had a similarity of 96% compared with Streptomyces aureofaciens. Based on morphological characteristics, culture, physiological and biochemical characteristics and molecular biological analyses, the strain 25.2 was identified as Streptomyces aureofaciens.

The study was carried out on corn kernels withoil content of 3.36 - 5.73% on dry matter basis in order to select the most suitable variety for oil extraction. The main processing parameters were also examined in order to select the best values which enhance the extraction yield and thequality of the extracted oil. The optimized processing conditions are briefly described as follows. Corn kernels were ground to particle size of 0.1 mm to 0.25 mm in diameter. The ground corns were then extracted two times by n-hexane at a ratio of 1 g ground corn to 8 mL solvent for 5 hours (the first time) and ratio of 1 g ground corn to 4 mL solvent for 2 hours (the second time). Extraction was carried out at 69oC. The extract was then evaporated by rotary vacuum equipmentto collect corn oil. The corn oil obtained has high levels of unsaturated fatty acids and vitamin E, and can be used as raw material in the production of functional foods and pharmaceuticals.

Clitocybe maxima is an edible mushroom with light brown color. Its fruiting body grows out as a stick, and then differentiates into a cap. Clitocybe maxima is also called bamboo shoot or long stem mushroom. The fruiting body contains plenty of amino acids and beneficial minerals esental for the human health. The present study investigated growth of C. maxima strain under liquid fermentation conditions. The experiment results indicated that the C. maxima mycelium grew best on medium containing 2 g yeast extract + 2 g pepton + 0.5 g MgSO4.7H2O + 15 g glucose + 1.5 mg thiamin + 1,000 ml distilled water. On this medium, C. maxima mycelium grew fast and mycelial dry weight attained 33.9 g/ 1,000 ml with highest number of mycelial pellet. Different oxygen supply significantly affected the morphology and mycelial biomass. The optimal concentration of oxygen is 0.75 liters/1 liter of medium/minute; the rate of original spawn of grade 1 for inoculation is 10% of the medium volume. The most suitable incubation time was 84-96 hours. The use of liquid spawn for mushroom cultivation can reduce cultivating cycle by 12 days.

The research was conducted to investigate cold storage techniques of gladiolus bulbs to increase sprouting rate and uniformity and to reduce rotting problem. The experiments consisted of post-harvest time storage treatment, storage duration, and post treatment planting date. Results indicated that, the bulbs after 30 days after harvest stored at 50C for 90 days showed lowest rotting percentage (5.2%), but high sprouting and rooting rate (85.4% and 85.6%, respectively). The lowest of bulb rotting percentage and better growth and development were observed in bulbs planted at 10 days of post-cold storage treatment

Using methods of pedagogical checking and classifying based on physical strength evaluation standards applied to students of all universities, the present study assessed and compared the general physical strength state of the female students of the first year, second year and third year at the unveristy. The results on general physical strength of female students could serve as the basis to provide the exercises suitable to their physical strength development.

In order to complete the procedure for F1 seed production with the yield more than 3 tons per hectare in summer season, various experiments for hybrid seed production were carried out in the field of Vietnam National University of Agriculture. The results showed that the growth duration of T1S-96BB was 78-80 days, 5-7 days earlier than the male line R7. Thus, the sowing time of T1S-96BB should be done around 20th June so that the heading time occurs after 5th September. The male parent R7 should be sown 5-7 days earlier than female T1S-96BB and the second male parent R7 sowing together with female to ensure perfect flowering synchronization. The proportion of the female line is 72-75% of the total seed production area while the rest is occupied by the male line and pathway. The spacing of the female line is 15cm x 13-15cm The 2R:16S ratio gave highest yield of F1 seed production. The quantity of GA3 application for F1 seed production is 130-160 gram+ 600 liters of water per hectare in two sprays: the first spray with 400 liters on total area and the second spray with 200 liter for R line only. The results of this study is considered as basis to establish the procedures for F1 seed production of TH3-7 combination with high hybrid seed yield and quality.

In this article, secondary data as well as primary data collected from households and businesses were used to evaluate real status and effectiveness of cooperation models between farmers and business enterprises in production and trading of coffee in the Central Highlands. Based on the analysis, we proposed measures to enhance sustainable linkages between the two actors in production and trading of coffee in the investigated region. The research findings indicated that these linkages help improve economic efficiency in households’ coffee production thanks to increased productivity, higher price, and manufacturing cost savings and improve the competitiveness of businesses (thanks to the stability of raw materials, and a source high quality coffee for exportation). However, there are many limitations and challenges to maintain or develop these current linkages, particularly in the production process, product sales, or access to supportive policies. Thus, in order to promote sustainable linkages between farmers and businesses in the production and trading of coffee, it is suggested to enhance the capabilities of farmers, encourage support for farmers from businesses, improve market development activities in business, and suitable subsidies from the Goverment.