This study was conducted from January to April 2007 aiming to describe and analyse the value chain of white clam industry ((Meretrix lyrata hay lyrate asiatic hard clam), and its focus was the marketing of hard clam in Tra Vinh province in relation to the other provinces. Major value chain actors in this study were: seed suppliers, grow-out farmers, food-size hard clam traders, and processors, as well as restaurants and supper markets. Technical-economic efficiencies of these actors were clarified in association with the analysis of their perception. This study also helps to produce major feasible solutions to support the organisation of a long term production and marketing of the grow-out farms in Tra Vinh and other coastal province in the south ofVietnamwith regards given to the community participation, poverty alleviation, fluctuation of cultured area, production, and value added.

Study was carried out in order to verify the effect of some cover crops on weed management. In green house conditions, results shown that the development of three cover crops have no effect by light intensity with the growth rate (fresh weight, gram.day-1) were 35.71, 10.45 and 3.73, respectively. In orchard conditions, these cover crops can successfully compete against the grass weed species. Ruzi  grass has been controlling over 99% of annual broadleaf weed species and sedges; tropical kudzu have no effect on the broad leaf weeds but appeared efficient against sedges and annual broadleaf weeds. Glyphosan 480DD (1.25 %) or  Gramoxone 20SL (0.625 %) gave good results in controlling grass weeds,  with efficacy of 97% and 83.36%, respectively. Application of the herbicide belong to glyphosate group still effect on total biomass until 2 months after treated, when others, for instance kudzu, Wedelia trilobata, or using weed cutter have no difference from non-weed control treatment. The population of earth-worms, and the earth beneficial insects have no effect by any of  the above control  methods when compared with completely non-weed control treatment.

Return of agriculture accounts for 85% of farmer's households income, in which the poor group earns per capita under the poverty line 200,000VND/ month, return of average group - 286,000 and rich group - 1,225,000VND/ month. Upland fields, cultivated only one season per year, such as traditional rice, Summer-Autumn rice, yam bean, ginger, cassava, mung bean, peanut are from 20 to 81 millions VND/ha/year. Lowland fields inner high dikes, cultivated three seasons per year, grow either 3-seasonal rice or 2-seasonal rice+field crops (mung bean, water melon) earn the high return over 40 millions VND. Lowland fields without high dike, cultivated two seasons per year, get return approximately 25 millions VND with early Summer-Autumn rice and Winter crops (mung bean, water melon for VN new year). It is necessary to solve the capital problem for farming, beef raising and the water for upland crops irrigation in order to increase the number of crop, to increase return and to alleviate poverty.

The article makes some starting points and the author wishes to get more attention as well as discussion on what opportunities internationally economic integration are bringing about to tertiary education in Mekong Delta. Another important point raised here is how the universities in Mekong Delta overcome the challenges, seize the opportunities in order to meet the demand of educational innovation.

Black Tiger Shrimp (Penaeus monodon) is one of the species cultured in many regions of the coastal area in Vietnam; intensification caused problems about environment for sustainable development. The research was carried out in Soc Trang province. The experiment on the wet season by two shrimp ponds with 4000m2/pond, and stocking densities were 20 ind/m2, initial size of postlarvae at stocking was PL15, depth water level was 1,2 m and culture duration was four months. The result showed that concentration of TAN was 1.36 ppm and accumulation of TAN was 16,4 kg/ha/crop, they are gradually increased from early to the end of the culturing time, and NO2 and NO3 were 1.47 ppm and 0,29 ppm respectively, accumulation of NO2 and NO3 were 17.61 kg/ha/crop and 3.43 kg/ha/crop respectively. However, PO4 concentration 0.1 ppm, and deposit of PO4 was 1.18 kg/ha/crop, whereas concentration TP was 1.08 ppm accumulation of TP was 13.01 kg/ha/crop; concentration TN was 2.89 ppm accumulation of TN was 34.70 kg/ha/crop. 

Data warehouse systems provide a unified and embraceable view of the company?s precious information assets to underpin business management. Nevertheless, the size of data warehouse and the complexity of query are two main factors impacting to user?s query performance. Since data warehouse tends to be very large and to grow overtime, retrieving the query results from data warehouse is able to be very time-consuming. One of the effective approaches to improve user?s query performance is view materialization technique.

The ethyl acetate extracts of the aerial parts of Eupatorium odoratum L. from Phu Yen province were investigated.  One of chalcones (4,2Â-dihydroxy-4Â,5Â,6Â-trimethoxychalcone)  was isolated from ethyl acetate extracts.  Its structure was interpreted from spectra including IR, 1H-NMR, 13C-NMR, HSQC,HMBC,MSand based on published data.  At the first time, this chalcone was tested on antimicrobial activity. The result showed that it inhibited lightly to P. aeruginosa, C. albicans and S. cerevisiae.

The results of this study showed that  the crude enzyme extract  of Trun Quan (Pheretima posthum) was the most active on both casein and fibrin substrates in comparison with that of  Trun Ho, Trun Que, Trun Com and Trun Chi. Period of autolysis to get highest protease activity was 4 days. The optimum conditions for protease activity were 55oC and pH 8 and 10. These enzymes were stable at 25-55oC and at pH 7 and 11. The protease fractions were purified by acetone precipitation in combination with ionexchange  and hydrophobic chromatography. SDS-PAGE activity staining on casein substrate without beta-mercaptoethanol revealed that the enzyme composition of Trun Quan was complex. It composed of 10 protease fractions with molecular weight in a range from 24,0 to 58,3 kDa.

Rice-soybean cropping system was introducted to compare with current 3 rice cropping in Tam Binh district, Vinh Long province from 2004 to 2007. Six farms were selected in which three were practiced the 2 rices + 1 soybean system and the others were control (3 rice cropping system). Crop yield, production cost, gross and net return, benefit cost ratio and some major soil characteristics were recorded and analyzed. Results showed that rice yield was not significant different between the two systems in Winter-Spring crop, but rice-soybean system was overyield compared with the control in Summer-Autumn crop due to the effect of soybean residue in Spring-Summer crop. Production cost was reduced, profit and benefit cost ratio were significantly highter in rice-soybean system. Soybean rotations enrich soil NH4+ and P2O5 after 3 years of farming. Summary, rice-soybean system should be developed in Tam Binh for economical and sustainable farming system development.

After the Catfish war in 2002, there have been a lot of changes in production, processing and marketing on pangasius market in theMekongDelta (MD). Trends of market development are identified as continuing increase in areas for raising, much-more interested product quality from the both of raiser and exporting-processing companies (EPCs), and the linking needs among raisers as well as between raisers and EPCs will be largely and deeply developed in the future. Developing a market information system and a whole fish-raising master plan for provinces in the MD as well as helping raisers connect with market are considered as important solutions for development of pangasius market in the MD.          

This study was conducted to determine the effects of paclobutrazol (PBZ) combining with thiourea on year-round flowering of Java rambutan (Nephelium lappaceum L.). Over 20-year old rambutan trees in Cantho city were used for this study from 2003 to 2004. The experiments were designed in randomized completed block design,four to fivereplications, and each replication equal to one tree. Treatments were the concentration of PBZ from 200 to 750 ppm applied by foliar spraying.  Four experiments were carried in the June, July, September and November which is off-season flowering of rambutan in theMekongDelta.  The results showed that spraying PBZ at the concentration of 500-750 ppm in early June may induce off-season flowering when appeared short drought, while treating in July, September or November trees appeared flower in early dry season, earlier than that of on-season flowering about 30 days.  PBZ treatments promoted flower bud initiation significantly earlier than that of the control about 1-2 wks, increased the percentage of flowering (30-240%), yield (20-75%), but did not affect on yield components, TSS and pH of flesh aril.

Nghiên cứu này mô tả thực trạng áp dụng khoa học kỹ thuật và các yếu tố ảnh hưởng đến hiệu quả sản xuất lúa của 261 nông hộ tại Cần Thơ và Sóc Trăng. Kết quả phân tích cho thấy, nông dân đã và đang áp dụng một số mô hình cải tiến như: giống mới, IPM, sạ hàng, ba giảm ? ba tăng, lúa - thủy sản, lúa ? màu; trong đó, việc sử dụng giống mới được nông dân áp dụng phổ biến nhất. Hơn nữa, nghiên cứu cũng chỉ ra rằng hiệu quả sản xuất của các mô hình canh tác lúa cải tiến cao hơn so với mô hình canh tác lúa truyền thống, cụ thể là thu nhập tăng 13,5% và lợi nhuận tăng 42%. Trong đó, trình độ học vấn, giống, phân bón, lao động, chuẩn bị đất, thủy lợi là các yếu tố ảnh hưởng đến thu nhập của nông hộ trên đơn vị đất canh tác lúa có áp dụng khoa học kỹ thuật.

At present, the vast majority of studies on the Vetiver grass focus on the functions of soil and water conservation, land reclamation and hillside protection. Vetiver grass has been widely known for its effectiveness in erosion, and sediment control. It is also known to be highly tolerant to extreme soil conditions (Truong and Baker, 1998). However, so far, little is known on the application of Vetiver grass as feed for ruminants. This study aims to investigate the total biomass yield and chemical composition of Vetiveria zizanioides under different harvesting times. The trial was a randomised complete block design with 3 treatments and 6 replications : the first harvest after 3 months and then every 30-day; 45-day and 60- day . Vetiver grown at spacing 50x30 cm between rows and within the row. Biomass Vetiver grass were affected cutting frequency. Vetiver grown at 50x30 cm resulted in highest dry foliage yield (tonnes/ha) at the 30 days of harvesting.

PI (Proportional Integral) controller is able to control a linear plant with good quality performance (fast transitional response and zero equal setting error). Therefore the controller has commonly used in industrial processes. PI controller is suitable for linear plants. With nonlinear plants, the classical controller can not insure the control quality at all equal state points. As a result, the paper presents method of using fuzzy PI controller for MIMO (Multi-input multi-output) nonlinear system and applying the way for controlling quadruple tank system. Fuzzy PI controller is built by using Madani fuzzy model and classical PI controller. The practical results were tested with simulink of Matlab. Basing on the result, fuzzy PI indefectibly controls the nonlinear system.

Essays are a kind of prose which has much contribution to Vietnamese literature, especially in modern time. In terms of Vietnamese literature, essays are firmly asserted to have had a process of development with their specific characteristics within the general rule of development of literature. However, it seems that there has not been any research on essays in respect of both theories and composition. On the basic of that, it is possible to make a distinction between essays and other kinds of prose. The solutions include many ideas such as:  review the literature concerning different points of view about classification of genre of essays, analyze the problems and suggest some personal solutions. In the end, identify some specific criteria based on typical characteristics of the genre in order to distinct essays with other kinds of prose.

Twenty six endophytic isolates from roots, stems and leaves of twelve sugarcane cultivars grown in fields in Cu Lao Dung district and My Tu district of Soc Trang province were isolated. With PCR technique using specific primers of nifH gene of Gluconacetobacter diazotrophicus, we could identify fifteen strains. These strains have the same characteristics with the G. diazotrophicus species. Molass is a good carbon source for G. diazotrophicus especially at the concentration of 10g/l, G. diazotrophicus reached  6,7 x 1010 CFU/ml after 6 days of incubation. Carriers containing of 50% of peat, 25% of filtercake,  25% of bagasse and 8% CaCO3 supported the good survival of G. diazotrophicus. After two months of storing at room temperature the viable count was still high 5,3x109 CFU/g.

Research on fluctuation of water quality and occurrence of shrimp and fish nature species in Baclieu province conducted in October 2006 at 4 main canals in Gia Rai, Phuoc Long and Hong Dan districts. Samples were carried out in three locations for each canal. The water quality was determined by specific methods. Aquatic resourses were collected by trawling net at 4 main canals and 3 hauls per each canal, name of species was identified based on previous researching results. There were 19 species appeared in research, some of species had high ratio such as Alpheuseuphosyne, Butis butis, Mystus gulio (18.26-36.78% in total 1,101 inds catched). Hauls had highest number such as haul 9,7,11 and 4 (>100 inds/haul). However, hauls had highest biomass was haul 11 and 12. Results that also Catch per unit effort was very little with 0.001-0.056 inds/m3 and 0.0003-0.084 g/m3.

In recent years, several researchers have used the digital image processing method with the help of continues Wavelet transform to solve the inverse potential field problems of geophysics interpretation. For this reason, we use the multiscale edge detection (MED) technique and a complex wavelet, so-called Poisson?Hardy wavelet to determine the horizontal positions and the depths of the sources from the measured geomagnetic field data ofMekongDelta.

Ninety households were interviewed. Water samples were taken from 18 cement?walled and earthen wells in six research sites in April, June and August 2003 to analyze for  NH3T, NO3-, FeT, As,  pesticide residues (Thiodan and Basudin), Ecoli and Coliform.  Results from the study indicate that there is no agency monitoring the exploitation of the resource. Shallow groundwater in sand dunes in the study areas is mainly used for watering cash crops, and domestic consumption. Generally, the quality of shallow groundwater in sand dunes in the case study areas meets the Vietnamese standard for groundwater (TCVN 5944 - 1995) and drinking water (TCVN 5501-1991). However, there are some parameters such as total Iron, Nitrate, As, Ecoli and Coliform that did not meet the standards in the second (June 2003) and third (August 2003) stages of sampling.