Vol. 11 No. 4 (2013)

Rhizoctonia solani Kühnis a soil-borne fungus that causes root rot disease on a wide range solanaceous, cucurbitaceous and fabaceous plants such as tomato, soybean, cucumber, yard long bean and groundnut. Field surveys conducted during 2011-2012 in Hanoi showed that the damping-off disease occurred on all host plants in the Hanoi region. However, the disease incidences varied from crop to crop, ranging from 2.8% on tomato, 4.55% on groundnut, 7.6% on cucumber to 7.46% on yard long bean. The morphological, biological studies and particularly pathogenicity tests of five R. solani isolates from five above-mentioned diseased plants showed that all isolates were identical in morphological, biological and pathogenic features. Bio-tests of the R.solani isolates on artificial medium showed that the antagonistic fungus (Trichoderma viride) is effective in controllingl R. solani. In the dual culture test (Petri disks test), the inhibition efficacies of T. viride to two isolates of R. solani isolated from tomato and cucumber were 79.1% and 79.8%, respectively. Potting test, in which plants were grown in sterilized soil in the greenhouse showed that the control efficacies of T. viride to these two R. solani isolates were 73.2% on tomato and 76.2% on cucumber..

After cutting apical buds, the axilary buds The rapid emergence of suckers or axillary buds after topping significantly decreases the yield and quality of waterpipe tobaco material. The sucker removal by hand results in increased labor cost. Using Accotab for sucker control was carried out with variety Re Den in the Spring 2011 and 2012 at Tien Lang. Hai Phong.The experimentwas conducted with Accotab concentrations of 1; 1.2 and 1.5% in order to determine the most appropriate concentration for sucker control without affecting yield and quality of the products. Experimental results showed that treatment of Accotab decreased the number, length and weight of axilary buds, but increased the leaf size and productivity of waterpipe tobaco products. Accotab concentration of 1.2% was found most optimal; this concentration brought highest yield (1625 kg/ha) and highest economic efficiency (79.56 million/ha).

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.

Two experiments were conducted to study the influence of growing medium (cv. Trau) and weight of seed rhizomes (cv Gie) on the growth, yield of ginger grown in bags. The bags were made of cement bag material with 40x40cm size. Ginger cultivar Trau was planted in bags containing 100% soil; 100% sand; 100% rice husk; soil – rice husk (1:1); soil – sand (1 :1); sand – rice husk (1 : 1); soil – sand – rice husk (1 : 1 : 1). Cultivar Gie consists of four different weight of seed rhizomes, i.e. 4 g, 8 g, 16 g and 32 g. The treatments were arranged in RCBD with three replications; the bags were placed under three-year old mango canopy with 70% natural light at the Faculty of agronomy, Ha Noi University of Agriculture. Growing medium significantly effected the growth and dry rhizomes yield of ginger. Trau ginger grown in soil – rice husk (1:1), 100% sand and soil – sand – rice husk (1:1:1) had higher growth and rhizomes yield than the other growing media. With Gie cultivar, number of pseuodstems per plant, number of leaves per stem, leaf size, leaf area, dry matter weight and yield component parameters of ginger increased proportionately with seed rhizome weight. Growing in medium of soil – sand – rice husk (1:1 :1) brought about highest yeild (53.8 million dong). 32 g seed rhizomes yielded in significantly higher rhizome yield than the other treatments, however, highest economical efficiency was obtained with 16g rhizome as seed.

This study examines the diversity and distribution of spiders in the mangrove areas in Con Trong, Ong Trang estuary, Ca Mau Province. Faunal samples taken along 4 transects and from 5 zones of Con Trong mangrove forest for two seasons (dry and wet), yielded a total of 440 spiders representing 54 species belonging to 14 families. Four families represented 81% of all spiders collected, with Tetragnathidae being the most abundant representing 35% over all, followed by the Araneidae with 16%, the Oxyopidae with 15% and Salticidae with 15%. Two species Tetragnatha nitens Audouin 1826 (Tetragnathidae) and Oxyopes matiensis Barrion & Litsinger, 1995 (Oxyopidae) were determined as the dominant species. Diversity of spider in Sonneratia-Avicenniahabitat (OTSAv) of Con Trong mangrove forest at Ong Trang estuary is the highest.

Leaves from eight-week old In vitro plants of Chrysanthemum indicum L. were cultured on MS medium supplemented with 1.5mg/l -NAA and 0.5mg/l BA to induce shoot regeneration. The influence of leaf posision, 1th to 6th from shoot tip, on shoot regeneration was studied. The highest shoot number was obtained from 3th to 4th leaves. Morphological changes and the role of endogenous hormones in shoot regeneration were analyzed and relationship of leaf position, respiration rate, and endogenous hormone were also discussed. In vitro plants derived from leaf calliwere developed on MS medium and transfered to pots to produce plantlets.

The aim of this study was determining biochemical characteristics of Streptococcusspp isolated from tilapia with hemorrhagic diseasein some northern provinces of Vietnam. 60 samples of tilapia with hemorrhagic diseasewere collected from 4 provinces in Hanoi, Hai Duong, Hai Phong and Quang Ninh. Five bacteria species such asAeromonasspp., Pseudomonasspp., Staphylococcusspp., Flavobacteriumspp. and Streptococcusspp.were isolated. The prevalance of Streptococcusspp. was 86.67%. All Streptococcusspp isolates had typical biochemical characteristics, belong to biotype 2 and identified as S.agalactiaeby API 20 Strep system. The antibiotics tests showed that Streptococcusspp. were the strongest sensitive with enrofroxacine and doxycyline.

The experiment was carried out to identify suitable feed for first stage of grow-out period of fourfinger thread finfish (Eleutheronema tetradactylum) in sea cages at average stocking size of 4.21 g/fish with a density of 8 fish/m³. Fish were fed with three different diets as three treatments: 1) CN (100% commercial pellet with 35% crude protein), 2) CN&CT (50% commercial pellet with 35% protein and 50% fresh trash fish) and 3) CT (100% fresh trash fish) for 60 days with triplicates. Growth performance and survival rate of fourfinger thread finfish were not significantly different among the treatments (P>0.05). Food conversion ratio (FCR) and size variation (CV) were considerably lower in CN treatment than those in other two treatments, reaching 2.40 and 9.81%, respectively (P<0.05). Environmental factors such as temperature, DO, salinity, pH và NH3 were in the suitable range for fourfinger thread finfish. This shows that commercial pellet (35% crude protein) can be substituted for fresh trash fish for first stage of grow-out period of fourfinger thread finfish.

A study on biochemical and physiological characteristics of blood wasconducted on 30 twenty-week-old Isa Brown chickens infected with Newcastle disease in 3 outbreaks and 30 healthy chickens of the same breed used as a control. Chickens infected with Newcastle disease showed reducednumber of red blood cells (1.79 million/mm3), the hemoglobin concentration (7.36 mg%), the hematocrit (23.08%), the mean corpuscular volume (128.94 μm3) and the mean corpuscular hemoglobin concentration (41.12 pg) in comparison with the control (P<0.05). In contrast, the number of white blood cells(20.41 thousand/mm3), percentage of polymorphonuclear leukocytes (57.8%), eosinophil (5.57%), monocyte (2.23%) and lymphocyte (33.7%) in WBC increased in comparison with the control (P <0.05). The blood biochemical indices such as the total protein content (18.19g/l) and the ratio A/G (0.64) of infected chickens were also reduced (P <0.05). These results have contributed to the pathological aspects of Isa Brown Chickens infected with Newcastle disease and can serve as a basis for diagnosis.

Luc Ngan isanimportant agricultural district of BacGiang province. The district has five main land use types, i.e.paddyrice, paddy rice – upland crops, vegetables– upland crops, fruit crops and forest. The key commodity crops arelychee, persimmon and Acacia. Ofthe current land-use types, lychee and acacia bring maximum economic efficiency in terms oftotal revenueperha per annum, mixed income,workday value and cost-benefit ratio. The land use typesof rice-rice and rice-upland cropsdo notbring not high economic efficiency but play a vital role inensuring food security. By 2020, 4,000-4,200 hectaresare projected forrice and rice and non-rice crops andabout 18,500 ha forlychee cultivation, of which12,000-15,000 hectaresdevoted to high quality lychee. Forestareawill be expandedto 33,000ha,mainly with Acaciafor timber and paper pulp.

Based on analysis of soil samples Hai Hau soils can be classified into 3 groups with 9 soil types, alluvial soil being the lagest area with 8,976.61 ha, occupying 39.20% of the natural area, followed by saline soil group with 4,8725.16 ha, accounting for 21.28% of the natural area. Sandy soil has the smallest area with 422.89 ha, occupying 1.85% of the natural area. The physical and chemical properties of all soil types are suitable for many types of annual crops. Soils have a good structure with soil thickness, porosity and soil texture from sandy loam to clay. The chemical properties of soils fluctuate strongly, especially soil salinity and depending on type of soil, but in general, soils react neutral to weak alkaline, with high basic saturation. Soils have medium to high phosphorus and potassium conccentration and moderate fertility .sandy soil group, however, has low fertility.

Improvement of Haplic Acrisols by residual vegetation is an effective and easily applied measure in the condition of Vietnam. In the Summer season the decomposition speed of residual vegetation is more rapid than last ones in the Spring - Winter season. In the Summer all of residual vegetation were decomposed after 5-6 months. From 3 residuals vegetation, the ground nut stem having most rapid speed of decomposition, then is wild chrysanthemum of Thailand and the last one is straw. Addition of lime with 1 tan CaO per hectare with microorgarnism products (CT4) led to the acceleration of decomposition speed of residual vegetation. In the summer season, in CT4 the decompositioned percentage of ground nut stem, straw and wild chryssamthemum of Thailand after 150 days of their buries was 87.2 -90.0%, 78.3 -81.1% and 79.1% respectively. In the spring winter the speed of vegetation residue decomposition is reduced approximate by a half but in CT4 its still highest.

Phytases are enzymes hydrolyzing phytic acid to release inorganic phosphate and myo-inositol.Phytase produced by microorganisms have potential industrial applications. The supplementation of animal feed with phytases reduces the cost of diets by removing or reducing the need for supplemental inorganic phosphate and increases the bioavailability of phosphorous in monogastric animals. In this study, soil close to pig and chicken farms at Ha Noi university of agriculture was used as a source material for isolating phytase producing bacteria. On PSM medium, six bacterial isolates having potential phytase production were isolated. Among these, M4 isolate showed maximum phytase activity. M4 isolate was biochemically characterized as Bacillus spp.

A study on the seed-sowing device of soybean sowing machine was conducted to determine working parameters as a basis for designing a soybean sowing machine. The technical parameters of the seeding plate were studied through laboratory studies about the influence of the thickness of sowing plate, diameter of sowing hole, angle of sowing plate and velocity of sowing hole on the possibility of taking seed of the plate. The results indicated that the seed-sowing device using the structure principle with tilting plate is appropriate with soybean because soybean seeds have a smooth and round shape. Through analysis of experimental results appropriate parameters of the seed-sowing device were determined as follows: thickness of sowing plate from 4 mm to 6 mm; diameter of sowing hole from 9 mm to 11 mm, tilting angle of sowing plate from 25° to 35° and velocity of sowing hole ≤ 0,35 m/s.

Climate change have been causing serious consequences for all the countries in the world, affecting all aspects of social and economic life, especially in the field of agriculture, forestry, fishery and people in rural areas. The perception about climate change (CC) and the impact of climate change is an important basis to point out appropriate solutions. The study used close-open structure (semistructered) questionnaires to investigate the state of the perceptions of 768 students at Hanoi University of Agriculture on the general concepts of climate change, causes and manifestations of climate change, impact of climate change on agriculture, forestry, fishery and life of people in rural areas of Vietnam. The analysis shows that the perception of the students at the university about climate change is at the average level. The students have quite good perception about the impact of climate change on agriculture, forestry, fishery and the impact of climate change on life of people in rural areas of Vietnam. Of those students, the senior students generally have better perception than those of junior, sophomore and freshman year students; the students of Department of Natural Resources and Environment have higher perception than the students of other departments. Some solutions which should be taken to enhance the perception of students are: providing special issues on climate change; conducting research on climate change, educating students on climate change; practicing specialized issues on climate change; organizing clubs / students’ network action to cope with climate change; opening competitions on climate change; training life skills, cooperative attitudes to dealing with climate change.

Autonomy which is an essential skill during learning process helps students acquire the knowledge more easily, which in turn triggers the learning effectiveness. Autonomy in English learning plays a much more crucial role. This paper aims to seek for form of learning, time, location and facilities, which support students in autonomy in English study. In addition, we define the causes, which effect to autonomy in English learning. We also define the role of lecturers during students’ learning process by investigating the actual situation at Hanoi University of Agriculture to arrive at recommendations to improve students’ autonomy in English learning effectiveness. Guiding learners to gain the autonomy is considered an important task of lecturers in the process of reforming teaching and learning in tertiary credit-based education. In order to achieve this goal, it is necessary to gain cooperation among learners-lecturers and school board of managers.

Errors and fraud reduce the efficacy in running business, especially in medium and small-sized enterprises (SMEs). Research hypothesis is that: are there factors of the accounting information system that associate with fraud and errors in SMEs. Research site focused on Hanoi since there is agreat numbers of SMEs in this area. The findings showed that application of information technology in accounting works; the frequency of inventory; the role of the managers in accounting information system and auditing works are the factors that have most impact to the frequencies of fraud and errors that occur in SMEs. From these findings, some lessons were drawn to minimize fraud and errors in small and medium-sized companiesy as well as to improve the role of accounting in business.