Vol. 10 No. 2 (2012)

Two field experiments employing Split-plot and Randomized Complete Block were carried out in spring of 2010 and 2011, respectively, at Gialam-Hanoi with the aim of determining compost dose and micro-organic fertilizer types suitable to cucumber. Research results showed that 30 tones of  compost and 2,500 kg of Song Gianh micro-organic fertilizer per ha could be applied to Thuan Thanh Cucumber varierty with high economic effectiveness, net income, high quality and  safe product.

This study was carried out to examine the effect of water stress on growth and yield of two mungbean cultivars DX22 and VN5 in the pot experiment under nethouse condition in comparison with full irrigation. For water stress treatments, irrigation was withheld at three developmental stages: beginning of flowering, full bloom and pod flling. Water stress was imposed until 70% of plants or 75% of leaves per plants withered and afterward the plants were rewatered for recovery, growth and yield assessment. Under water stress conditions, the rate of photosynthesis, rate of transpiration, pods per plant, and individual grain yields were all adversely affected. Grain yield reduction (weight of 100 seeds and seed yield) was greatest when water deficit occurred at the pod filling stage.

This study aimed at defining most suitable planting density for high tuberous root yield of mondo grass. The row spacing varied from 30 to 50 cm; while intra row spacing from 10 to 16 hills/m2 with 1 to 3 shoots per hill. Results showed that  the planting density exhibits clear influence on growth and tuberous yield of Mondo grass. Spacing at 40x20cm with 3 shoots per hill was proved most positive on growth and tuberous root yield. The net profit achieved  was 178,23 million VND/ha/3 years.

The orchid Dendrobium fimbriatum Hook (Hoang Thao Long Nhan), a beautiful orchid species, which is currently used for house decoration as well as medicine, is in danger of being extinction. In vitro studies of orchid Dendrobium fimbriatum Hook. (Hoang Thao Long Nhan) were conducted in order to conserve and increase the genetic pool of this precious orchid species. The results showed that the suitable materials used for micropropagation were 3 months old fruits. Most suitable medium for germination and protocorm formation was MS+100ml ND+10g saccharose+6.0g agar/liter. The optimum medium for propagation of protocorms was KC +100ml ND+10g saccharose+60g potato+6.0g agar/liter. The most appropriate medium for fast in vitro propagation of shoots was MS+100ml ND+20g saccharose+60g ripe banana+6.0g agar/liter. The medium used for growing of complete plants was RE+10g sacharose +1g THT+6.0g agar/liter.

This experiment was carried out in 2011 Spring season to evaluate the effect of polymer-coated, slow-released nitrogen fertilizer on growth and yield of maize grown on Red River alluvial soil at Gia Lam, Hanoi. Four doses of slow-released fertilizer, viz. 150 kg N/ha, 120 kg N/ha, 90 kg N/ha and 60 kg N/ha were used to compare with the conventional broacasting practice as control (150 kg N/ha). The results showed that doses of  90 – 150 kg N ha-1 of slow-released N fertilizer resulted in better growth and higher yield (yield increase by 4.8 – 10.8%). It was suggested that for maize cultivar LVN4 90 kg of slow-released N formulation be applied for in spring season for highest yield and economic efficiency.

A suitable protocol for meristem-tip culture for garlic (Allium sativum L.) to eliminate viruses was studied and established. The presence of viruses were identified by: (i) mechanical inoculation of  inoculum isolated from infected garlic plants on indicator Chenopodium album L. and (ii) RT-PCR using potyvirus degenerate primers. After pretreatment with ethanol (70%) for 1 minute, shoots from infected plants were further treated with sodium dichloroisocyanurate (5g/l) for 5 minutes to eliminate microorganisms. Under a microscope, leaves of infected plants were removed one-by-one and meristems were excised and grown on MS+30g saccarose + 1mg BA/l to produce shoots. It is indicated that to get completely virus-free plants, meristems shoud be excised with size below 0.3 mm in length. If the exised meristem explants are of 1mm in size the culture medium should be added with ribavirin (20mg/l). The virus-free shoots that were multiplied on MS + 30g saccarose + 0,5mg αNAA/l + 2,0mg BA/l media yield not only the highest regeneration rate (4.08 times) but also the best growth (7.55cm). Adventitious shoots can also be regenerated via calluses on MS + 15g saccarose/l + 10g glucose/l + 5g manitol/l + 2,0mg BA/l media. The best medium for root generation was MS + 30g saccarose + 0,5g activated charcoal/l + 0,5mg αNAA/l, on which, 100 % shoots produced adventitous roots (5.19 roots per shoot on avarage) and the resulting plants grew normally.

Evaluation was carried out on growth, development and yield of three musk melon varieties introduced from China in Hanoi University of Agriculture, in 2011 Autumn - Winter season. The results show that all of varieties have morphological characteristics as diameter of fruit, weight of fruit, colour of fruit of skin meeting the consumers’ preference. These varieties show good growth potential, hight pest resistance, with marketable yield of 21.0  to 34.3 tons / ha.

Dendrobium chrysanthum Lindl. is one of the important orchids that face to the situation of extinction, is overexploited. This orchids are need to preserve, expoit and recover sustainably. The experiment was conducted to evaluate the effect of nutrients: Antonik, Yogen, Growmore, Đầu trâu and DDTC on the growth, and development, diameter of trunk, the number of leaves and the bud formation of this orchids. The result shows that Antonik is the most suitable to the “Ngọc vạn vàng ánh”. The orchids was test by Antonik after 75 days, had plant height: 41,12cm, diameter of trunk: 6,72mm; leaf number: 15,5. Antonik is not only affect to the growth of trunk and leaves but also promote to the development of plants. Yogen increases the height of age 1 and age 2 in orchid. “Đầu trâu” has the effection in the number of leaves in both groups of the orchid.

The effect of phosphorous fertilizer dose on growth, development and yield of spring vegetable soybean was investigated at Gia Lâm, Hà Nội to identify optimum phosphorous fertilizer dose on two soybean varieties, DT02 and AGS346. The experiment was performed in triplicate in a split - plot design. It was shown that phosphorous fertilizer dose of 90kgP2O5ha-1 plus 30kgN + 60kgK2O ha-1 is optimal for leaf area index, dry matter accumulation, number of nodes, number of pods per plant and pods yield for both varieties.

Biological characteristics of Coranus spiniscutis Reuter were examined at the Department for Experimental Entomology at Institute of Ecology and Biological Resources in Ha Noi, under laboratory conditions: temperature 26.1 - 30.8 0C and relative humidity 75.6 - 80.5 %. The preys were larval stages of Corcyra cephalonica belonging to the order Lepidoptera. Results showed that the total life cycle of C. spiniscutis is 47.86 ± 2.59 days, consisting of 8.19 ± 0.42 days egg period, 34.07±0.69 days of nymph stage and 5.6 ±0.28 days of oviposition period. The female of C. spiniscutis can lay from 72 to 110 eggs (average is 90.35 ±8.51 eggs) with the hatching rate of 85.43 ± 5.23%. At temperature of 300C and relative humidity of 75% the life cycle of C. spiniscutis was 45.07 ± 2.32 days, including 7.62 ± 0.31 days period, 32.95±0.59 days of nymph period and 4.5±0.22 days of egg laying. Both larvae and adults of C. spiniscutis had high capacity to consume the second to fifth instars of C. cephalonica . Daily consumption of a C. spiniscutis adult were 2.4±0.03 individuals of the first and second instars of Corcyra cephalonica, 3.5±0.16 individuals of the first and second instars Spodoptera litura, 2.4±0.15 individuals of the first and second instars of Plutella xylostella and 1.6±0.09 individuals of the first and second instars Hedylepta indicata.

The characteristics relative to flowering, pollination, fertilization of  some Thai Adenium obesum accessions were investigated at the Faculty of Agronomy, Hanoi University of Agriculture. The results showed that stamens and pistils mature at  48 hrs. and 72 hrs after anthesis, respectively. The pollen viability of different accessions was high, ranging from 90.1±3.9% to 95.7±0.7%. The fruit set of the cross combinations varied from 25 to 100%. The colour characteristics of hybrid fruits were regulated by the  parental species. The fruit color was maternally controlled. The germination rate of Adenium obesum crossed seeds reached from 64% to 90.5%, and 25% to 97.4% of seedlings were obtained.

A study was undertaken to determine the prevalence and virulence of E. coli isolated from meat of domestic animals in some districts of Hanoi. A total of 90 samples of meat (pork, beef, and chicken) were taken from 11 market places in Gia Lam, Dong Anh, and Soc Son. Results showed that the percentage of meat samples meeting the hygienic standard was different among  the threetypes of meat and the studied places. In detail, the percentage of  pork and beef samples unsatisfying in terms of E. coli contamination was 53.33% with the highest found for chicken meat (60.0%).  All (100%) of the isolates of E.coli from meat samples had high toxicity, killing guinea pigs within 24 to 72 hours. There were three strains belonging to O26, O55,and O157 antigen groups that could be hazardous to consumers. The results should warn consumers of the quality of meat available in the local market places.

A feeding trial was carried out to determine effects of replacement of elephant grass (Pennisetum purpureum) with water spinash (Ipomoea aquatica) at different levels in the diet on feed utilization, growth and carcass performances of exotic rabbits. A total of 30 New Zealand White rabbits at 1.5 months of age were randomly divided into 5 groups of 6 each to be fed individually on diets in which 0, 25, 50, 75, or 100% elephant grass was replaced with water spinash. Results showed that intakes of dry matter (DM) and organic matter (OM) were highest when water spinash accounted for 50-75% of forage in the diet. The more was the proportion of water spinash the more were the intake of protein (CP) and digestibilities. The average daily gain (ADG) was increased (P<0,001) and feed conversion ratio (FCR) reduced accordingly (P<0,001) when the proportion of water spinash increased up to 75%. Live weight and carcass weight were increased (P<0,01) with the increase in the proportion of water spinash while the carcass composition was not significantly affected (P>0,05).

Salmonella isolates from faeces and organs of postweaning pigs with diarrhea in 9 industrial farms in 6 northern provinces of Vietnam comprised 5 serotypes. S. typhimurium serotype made up 51.61% of the isolates, followed by S. anatum (19.35%), S. agona (16.14%), S. meleagridis and S. ruzizi (6.45% for each serotype). All of the isolates were resistant to streptomycin and most of them were resistant to tetracyclin, amoxicillin, ampicillin and sulfatrimethoprime along with very high virulence. The snt gene coding for enterotoxin production and invA gene coding for invasion factor were detected in most of the isolates. These two genes were detected in all of the S. typhimurium isolates. The results indicated that S. typhimurium may play an important role in diarrhea symptom of pigs in the northern provinces of Vietnam.

A total of 2970 semen straws of 33 HF bulls of differenret origins being raised in Moncada Bull Center were AI to cows raised in 3 different places to investigate effects of individuals, bull origins, cow raising places and lactation on conception to the first AI. Results showed that pregnancy rate after the 1st AI by individual bulls varied significantly and were relatively high, ranging from 55.94% to 69.03%. In particular, the rate was highest for bull No. 2121 and lowest for bulls No. 2103 and 2105.  Results also showed that the origin of bulls did not affect the pregnancy rate after first AI, while two other factors, viz. cow raising places and lactation significantly influenced. The conception rate to the 1st AI were highest in Moc Chau (61.91%), and lowest in Thanh Son (57.89%) (P <0.05). The conception rate was higher for of cows in lactations 1, 2, or 3 than those in lactation 4 or 5.

PRRS causes severe economic loss for the farmers. Post weaning piglets are highly infected with PRRS because of high sensitivity and low immunity with PRRS. The present research was carried out in post weaning piglets at age from 3 weeks to 6 weeks. The piglets showed deprssion, anorexia, fever, red skin, dyspnea. The piglets also showed congested and hemorrhage lung and pneumonia, and enlarged lymph nodes, hemorrhage kidney. The microscopic lessions consisted of inflammatory infiltration in lung, pneumonia or bronchopneumonia, hemorrhage in pelvis of kidney. The piglets with the above clinical signs and pathological findings were diagnosed to be infected with PRRS by RT-PCR.

The present study was the first study in Vietnam on assessment of exposure to mercury in seafoods for the population in Nha Trang. The shellfish consumption data were combined with mercury contamination data in seafoods by probabilistic analyses performed with @Risk international for Excel to estimate the mercury intake for six sub-population groups: men and women at 18-29, 30-54, and 55 and over years of age. The dietary intakes of mercury by the Nha Trang population groups were compared with the Provisional Tolerable Weekly Intakes (PTWI) of mercury (5mg/kg b.w/day). It was found that there was no risk concerning the levels of exposure of Nha Trang consumers to mercury due to the seafoods consumption.

Agriculture plays an important role in the economy of Chuong My district. However, the cultivated land area of  agriculture sector has been declining rapidly as a consequence of urbanization and industrialization recent years. This study was conducted to define the trend of land use in Chuong My in order figure out an appropriate measure of using agricultural land and promoting sustainable development. In the period from 2005 to 2010, agricultural land is declining rapidly 204.99 annually due to landuse change pattern as well as industrial zone development.  Aquaculture land is increasing in several communes with lower topography. The great change was observed for areas of annual and perennial  crops due to commercial agriculture such as bonsai, flower, vegetable. To maintain sustainable development, it is proposed that the balance between economic growth and environment should be taken into account before converting land to other uses.

This study aims to investigate strengths and difficulties of the performance in compensation and land clearance process in Tien Hai District, Thai Binh Province. The used methods are of data collection, survey, synthesis and comparison in order to evaluate the compensation and ground clearance of 3 key projects of this district. According to the findings, many related land owners generally agreeing that  the compensation and ground clearance have been done on time and complying with the law of government. However, there are some limitations could be pointed out which are: the differences between document and reality in term of land measurement; the compensation usually be done by paying money, rarely by swapping  land; the people who have been collected more than 30% total land use, received no additional assistance except compensation to resettlement; there was 12,6% of people lost land  are unemployment. Proposed solutions for these problems are improving the capacity of institution in managing land, especially, in term of  land registry; diversifying the compensation policies; building long-term aids and employment policies; building a guideline of using  tools in compensating and assisting.

As a source of inoculation starters in the manufacture of alcohol from rice varieties from the Mekong River Delta, Vietnam, Banh men has been produced since the ancient time. These starters, which normally combine three groups of microorganisms, viz. yeasts, bacteria and moulds convert the starchy materials into fermentable sugar and subsequently to alcohol and organic acids. Yeasts are significant in the production of traditional beverage because they play the main role in alcoholic fermentation. Of 128 strains of yeasts isolated from rice fermenting staters in the Mekong River delta, 30 yeast strains were identified to be thermo-resistant at 50oC and  ethanol tolerance at 17% (v/v) in the challenge test with added ethanol with good flocculation and sporulation. From characterization of 10 yeast strains, 7 yeasts strains were identified as Saccharomyces cerevisiae and 3 others as Clavispora lusitaniae.

The study was carried out on the canola (Brassica napus L.) cv. TP3 Hpro, in order to select the processing method most suitable to the technological facilities available in Vietnam and to optimize the processing techniques. The canola seeds of TP3 Hpro (with 41.99% oil content) introduced from Australia were sown in 2010-2011 winter-spring season in Ha Giang province. Expeller pressing, where raw materials are squeezed under high pressure in a single step, is the most suitable method that could be easily implemented in Vietnam to extract oil from the canola seeds. The main processing factors were examined in order to enhance the oil extraction yield and oil quality. The optimised processing conditions are listed as follows. The seeds were crushed to coarse powder with particle size of 1 mm. The powder was then steamed at 100°C for 50 min, followed by a drying step at 90°C for 12 min. After that, the powder was placed in the pressing equipment and was acclimatised at 55°C before being pressed. The pressing capacity was 9 kg of powder per hour. The canola oil obtained was classified as salad oil with high nutritional values since it does not contain erucic acid, yet has relatively high levels (19.2%) of essential unsaturated fatty acids, such as omega-3 and omega-6.

The Government of Vietnam has implemented comprehensive policies for the purpose of poverty reduction in recent years. Besides remarkable achievements, there are several concerns about effectiveness and quality of public investment policies for poverty reduction. Based on assessing the current situation, this article points out clearly 7 problems faced with in the process of policy implementation in Ha Giang Province, such as need assessment and poverty reduction planning, the coordination among other projects/programs, investment decentralization, monitoring and evaluation and mobilizing the rural beneficiaries’ participation in the policy implementing process. The article concludes by proposing policy recommendations for improving the effectiveness of public investment in Ha Giang Province in particular and contributing for the efforts of rapid and sustainable poverty reduction of the nation.

The study was conducted in Truong Giang Co. Ltd, Hai Duong city. The main objectives of the study were i) to analyze impacts of economic recession on business activities of the company; ii) to understand adapting sollutions applied by company to overcome the negative impacts of economic recession, and iii) to propose feasible sollutions to help the company do business more efficiently under economic recession conditions. Systematical and participatory approaches; comparision and consultancy methods are main methods applied in this study. Results of the study show that economic recession has reduced capital sources, especially banking sources; increased input prices and changed payment methods of input suppliers that made business activities of the company more difficult; economic recession had negative impact on 82,6% labor force; and 62,6% of them has income reduced; Business efficiency has reduced in all indicators, especially in 2009 (ROS: -2,36; ROE:-2,80 và ROA:-1,64) and living standard of 82,9% labors has also reduced. To response to economic recession, the company has applied various sollutions. Exploition of government’s stimulus funding package; renegotiation and finding out more input suppliers; appropriately capital borrowing using plan; and better use of labor force are main sollution suggested by the study.

Vietnam Tourism has become a focal industry of the country, accounted for 4% of the GDP. The sector has also contributed a considerable amount to the state budget. Vietnam has been rated as a fully potential destination for international tourists, however we have not taken advantage of such strengths. Therefore, forecasting tourist arrivals in coming years is very useful for managers and investors, who can base on this to perform their businesses better. The paper applied the Box-Jenkins method to build an appropriate ARIMA model for forecasting outbound tourist arrivals to Vietnam, using monthly data from Vietnam National Administration of Tourism. The findings show that among the trial estimated models, ARIMA(12,1,12) is the  most appropriate model. Based on this model, shorterm forecasts on outbound tourist arrivals to Vietnam in early months, 2011 has been done with errors varying from 14 to 27%. However, ARIMA model could be used for forecast, but it could not be optimal selection since autocorrelation and moving average in the model are assumed tobe linear.