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Activities of vegetable and fruit itinerant dealers in the Hanoi streets, some proposals for management: The number of itinerant dealers is continuously increasing and field of action is unrestrainedly expanding in the Hanoi streets. The income from itinerant trade could be estimated at 10 M VND/year on average, waking up 54 % of total income of a household. This is livelihood-generating source for a great deal of people. However, activities of itinerant dealers bring about a lot of evils in social security, public communication safety, and environmental pollution. In order to improve this situation if is needed to apply various policies aiming to enhance the effectiveness of administration in parallel with the special regulation for “roadside economy”.
Analysis of economic effectiveness of forest plantation in Vietnam: Economic effectiveness is the most important criterium for assessing forest plantation. The content of this artide is a part of the study on economy of forest plantation. A mathematical method was presented for financial analysis; analysis of investment in silviculture; analysis of intemal rate of return (IRR) and the method for choosing options of investment based on IRR.
Appraisal of saline tolerance of some short growth duration rice varieties: Salt tolerance varieties have generally been considered as the most economical and effective way of increasing crop proctuction in saline soils. The authors investigated the genetic basis of salinity tolerance and using microsatellite evaluated improve-varieties. Phenotypes were evaluated by visual score of salt tolerance at vegetative and reproductive stages under saline stress of EC 12=dS/m in phytotron. To examine the powever of the idenlified SSR marker in predicting the phenotype of the salt locus, the authors ditermined the genotypes of the 49 improve varieties at RM 315 locus. The results indicated an accuracy of more than 100% in identifying the resitant plants which was similar to that using RG 315. The results of the germplasm survey will be useful for the selection of parents in breeding programs aimed at transferring these genes from one varities background to another and use in mark assited selection.
Calculating and establishing the hydrostatical power transmission for trees hill drilling machine: In order to successfully implemenling the national plan to grow 5 millions hectas of forests which is assigned to Agriculture sector in the period of 2006-2010, it need to be partially or fully mechanized the forest recovering program and hills drilling is considered to be the most important part of that work. Forest trees hill drilling has its typical characteristics, drilling soil is mixed with tree roots, stones and other miscellaneous things, therefore the loading force on the drilling machine axis is always changed in the large scale leading to the uncapable of mechanical power transmission to the drilling parts. This paper introduce the methods of calculating and establishing the hydrostatical power transmission for the trees hill drilling machine to increase the safety of power transmission as well as the convenient using and highly economical effectiveness.
Effectively using of available feed resources for pig production at small farms in Quang Binh province: Studies on processing and using of available feed resources for pig were conducted at Duong Thuy commune, Le Thuy district, Quang Binh province. The results shown that the nutritive values of crude protein, lipid, crude fiber, total ash and NPN in KM 94 cassava roots and leaves were not affected after 30 and 60 days ensiling. The HCN content of KM 94 fresh cassava roots was 479 mg/kg DM and decreased by 330.8 mg/kg after grinding and spreading on 3 hours shading, continuously decreased by 130.9 mg/kg and 55.26 mg/kg after 30 and 60 days ensiling, respectively. Leaves of the KM 94 variety is high protein content (21.9%) and high HCN content (1665 mg/kg VCK). HCN content decreased by 425 mg/kg after chopping and 24 hour wilting. After 30 and 60 days of ensiling, HCN content decreased by 202.6 mg/kg and 96.15 mg/kg, respectively. Using 20% (as DM) KM 94 ensiled cassava roots and leaves in fattening pig diet without affecting the live weight gain (control treatment was 522g/day and experimental treatment was 509g/day), feed conversion ratios (control treatment was 3.37 and experimental treatment was 3.44 kg feed/kg LWG) but feed costs for growth were reduced by 8% in expenmental treatment.
Efficiency of fattening on meat production in F1 beef crossbred bulls: Twelve F1 beef crossbred bulls namely Charolais x Lai Sind, Brahman x Lai Sind, Droughtmaster x Lai Sind and Lai Sind are used in this study. Each crossbred consists of three bulls ranging from 16 to 17 months of age. The bulls are fattened and fed completely indoor by 67 to 70% concentrate in the diet lasting in three months. The results show that F1 Charolais gains roughly 1,148g/day in body weight percentage of carcass and pure meat are about 53.9% and 43.6%, respectively. These indices are higher than other crossbreds such as F1 Brahman (l,l04g/day, 49.9% and 39.9%) F1 Droughtmaster (891g/day, 50.76% and 40.96%) and Lai Sind (833g/day, 47.92% and 38,35%), respectively. ME consumption for weight gained in F1 Charolais, F1 Brahman Lai Bind as well as F1 Droughtmaster is approximately 15.~ 16.4 19.4.and 19.8 Mcal/k~ respectively. Protein content of fillet in F1 Charolais is around 22.45% compared with 20.2% in Lai Sind and Lipidpercenfage of fillet in F1 Charolais is 4.47% that is lower than 6.22% in Lai Sind. This is might be due to the different structure of marbling in which Lai Sind is higher than F1 Charolais.
Experimental results on maize hybrid trial in spring 2005 of Tuyen Quang province: The trial result showed that: Duration of all hybrids in the experiment seems to be little short, suited to Spring season in the region of Tuyen Quang province. They could be cultivated in the paddy land with one crop without any negative effect to coming crops in Autumn season. It is said that, it is possible to plant these hybrids on the slopping land, but it should be conducted at suitable moisture soil and erosion control is needed. The yields of all hybrids are similar to the control, LVN 4. Of which, yields of LVN 14, B 9034 and LVN 16 are highest (5.167-5.323 tons/ha), higher than significantly the control of LVN 4 at = 95. Therefore, it would be nice, re-experiment of these hybrids in several seasons to get exactly data is needed, and it is possible to disseminate these hybrids of LVN 14, LVN 16 and B 9034 in larger planting area.
Formula to calculate the deepest depth of local scour hole in the lower Cuu Long river at the reach which has the main flow attack river bank by dimensionless analysis method: The purpose of this research is to determine the stable deepest depth of the scour hole in natural river. Based on analysis of influenced factors to the deepest depth of scour hole at river reach, the main factors are determined, involving river flow, riverbed and mutual impact force between river flow and riverbed. Elements related to the river flow are channel-forming discharge (dominant discharge - Q), hydraulic radius upstream of scour hole (R). Factors related to river bed are bed material grain size (d) and bank slope (i). The mutual impact force is impulse force, which depends on both the attack angle of the main flow direction and the bank line, and the bank slope. Applying dimensionless analysis and pressure of jet flow exerting on flat plate, the research find out the general formula to calculate that depth and test for the Lower Cuu Long River. Results proved these formulae are acceptable to contribute to research on training method for reducing the deepest depth of the scour hole.
High technology applied in agriculture should be linked with industrial scale production: The application of high technology in agriculture under the conditions of Vietnam should be characterized by the following specifications: l/ Grey matter content should be high, able to make breakthrough of yield and quality of agricultural products. 2/ Agricultural production effectiveness should be high. 3/ Environmental safety and thus, health of communities should be ensured. 4/ Technology should be applicable at industrial scale.
Morphological features, classification and distribution of pine sawflies in the South Vietnam: Sawflies are a group of the hymenopterous insects costituting the family Diprionidae. They are found more abundantly in the South than in the North of Vietnam and arranged as the most dangerous among the detrimental to pines insects. In this paper, there presented the new findings on morphology and distribution of sawflies in Thua Thien Hue, Pleiku and Da Lat provinces. In these regions five sawfly species have been identified, those are Diprion sp., Gilpinia sp.1, Ginpinia sp.2, Gilpinia sp.3, and Neodiprion sp. Morphological, ecological and biological characteristics of these species were described.
Preliminary results on artificial reproduction of siganus guttatus Bloch fish: The studies on effect of feeds and artificial reproduction were carried out in Thua Thien-Hue lagoon areas in 2005-2006. Results show that the use of CP (Thai feed company) with or without squid oil affected possitively mature rate of male (96%) and female fish (>98%); reduction of salinity in fish container resulted in laying eggs with 269 to 957 thousand eggs/kg live weight, however, larva died upto 4 days of age, and reason should be clarified.
Research and evaluation of erosion in catchment of Tri An lake: Tri An reservoir is the last water control works of the Dong Nai and La Nga river system with the catchment about 15,000 km2 and the topography of alternate hills, mountains and plain. The annual rainfall in the catchment is about 2,000 mm causing high erosion for slopy areas to affect the soil, water quality and security of the reservoirs in the catchment. Based on the satellite image and data set of soil characteristics, rainfall and hydrology the author use the modernization procedure to cempute erosion coefficients and build the zonning maps of slope, flow directions, geomorphology, plant covering, land erosion and rainfall. Using the. GIS method to compute and build a status quo of land erosion of all Tri An. catchment for the purposes of sustainable socio-economic development, reservoir security and environmental protection.
Revenue in forestry sector: Challenges and directions: This research focuses on sources of revenue in forestry sector. Basically, these sources come from tax on natural resource use, land use tax, non-timber forest products (NTFP) import and export tax and fines for violation of laws and regualations in forestry activities. Expenditures for forestry sector are also considered. These spendings are grouped in two types: investment and current expenditures. There is a quite large gap between revenue and expenditure, although this gap is narrowing down from 2001 to 2004. Directions on increase of revenue in forestry sector could be: to promote forestry resources valuation, to trengthen monitoring and evaluation activities for tax collecting process, increase in investment and other solutions for production forest and NTFP development.
Some measures for conserving the quality of flowers after cutting: Experiments were conducted to test the effects of the chemicals silver nitrate (SN), silver thiosulphate (STS), between 20, 8-hydroxyquinoline (8-HQ), citric acid (AC and saccharose on prevention of ethylene evolution and improving quality and longevity of cut flowers (rose, camation, gypsophila and lisianthus) under ambient temperature conditions at Da Lat and Ho Chi Minh city. Results indicated a promise as the flowers maintained their freshness and vase life significantly longer (30-70%) than the control when they were pulsed by a solution of SN + STS followed by a treatment for recovery of water conductance by between 20 + CA + saccharose solution. A nutritient solution of saccharose + 8-HQ + AC also significantly prolonged the flowers' in-vase freshness and increased the blooming capacity.
Some techniques applied in the nursery for Aquilaria crassna seedling production: A study on techniques of seedling production of Aquilaria has been conducted at An Giang province (South Vietnam). The influences of some factors on growth, namely the materials used for tubes and fertilizer composition, were made clear.
Study on using natural puzzolana as substitute for fly ash of thermoelectric plan in technology of rolling cast concrete (RCC): For construction of hydraulic dams in Vietnam it is needed to use ash concrete so far. Fly ash, raw material for production of ash concrete, comes from thermoelectric bases. At present, demand for ash concrete furiously increases due to development of hydraulic electricity. Lack of fly ash becomes an actual problem, to which the only solution is to find out the substitute. This paper presented the result of the study on using natural puzzolana as substitute for fly ash in technology of RCC.
Studying on establishing of maize pure lines by anther culture technique in stage of 2004-2005: In recent years, anther culture technique for maize hybrid breeding have been intensive studying and gained great achievements. In this study, the authors presented the result of creaang double haploid from anther culture in stage of 2004-2005. At this time, the research focused on developing of materials which could be created double haploid lines containing good characteristics for commercial breeding. In a number of 32 materials accession, there are 26 materials which have reacting to create embryo and F regenerating of plant. The paper have created 112 homogenous double haploid lines with stable heredity from 5 materials, in which, 78 double haploid lines from 4 materials have quite good characteristics can be used directly for hybrid breeding system.
The effect of lysine levels in the diet of pregnancy and lactating periods on reproductive performance of Mong Cai sows: 12 of Mong Cai pregnancy sows were selected and devided in to four groups at Trieu Hai State farm. In the pregnancy period protein levels in the diet wase 12% and lysine levels in the diet from group 1 to group 4 respectively: 0.50, 0.60, 0.75 and 0.90%; In lactating period, protein levels of 14% and lysine levels from group 1 to group 4 respectively: 0.60, 0.75, 0.90 and 1.05%. The results shown that suitable of lysine levels in the diet fore the Mong Cai sows: In the pregnancy period is from 0.60 - 0.75% and fore lactating period is from 0.75 - 0.90%.
The impacts of the number of kali fertilizer drilling application on production of field pea at Da Lat: The objective of the study was to determine the appropriate potassium (K) rate and number of side dressings on seed production of CPX 58 garden pea under the conditions of the dry season at Da Lat. The experiment was conducted in a split-plot design with 3 replications. The main plot was K rate with four levels namely 120, 150, 180 and 210 kg K2O/ha. The sub-plot was the number of application as side dressings, namely, twice at the 25 and 40 days after sowing (DAS), three times at the 25, 40 and 55 DAS, and four times at 25, 40, 55 and 65 DAS. Rate of K application had significant effect on yied and percentage of germination of the seed harvested. The rate of 150 kg K2O/ha gave the highest yield, percentage of seed germination and fertilizer efficiency. Three side dressings of K during the cropping season increased seed yield by 3.3 to 3.8% compared to that with application of two and four side dressings, respectively. Application of three side dressings for the rate of 150 -180 kg K2O/ha gave the best results on yield and economic efficiency.
The influence of KO2 fertilizer on yield of vegetable at Lam Dong: Effecfs of potassium fertilizers KCl 60% and K2SO4 48% on yield of cabbage, potato, tomato and hot peper grown on low pH soils in Da Lat and Duc Trong, Lam Dong province, were investigated during rainy summer 2000 and dry winter season 2000 -2001. Results obtained indicated that there was no significant differences between the two kinds of potassium fertilizers at the same low level of application of 120 - 150 kg K2O per hectare. In comparision with KCl, K2SO4 however tended to give lower yield of the crops investigated. Significant effect in increasing crop yield was observed when level of potassium increased from 120 and 150 to 180 and 200 kg K2O per ha on all crops in both seasons. Results also showed that potassium application had an considerably obvious effect in improving yield and quality of products in comparision with the control without potassium.
The influence of basal nitrogen fertilizer application and sowing density on productivity of field pea at Da Lat: The study “The influence of different rates of application of N fertilizer and seed sowing distance on dry seed yield of garden pea (Pissum sativum L.) in Da Lat” was undertaken in Da Lat city, from October 2004 to February 2005. The objective of the study was to determine the appropriate N and the optimum sowing distance for seed production of CPX 58 garden pea under the conditions of the dry season at Da Lat city. The experiment was conducted in a strip-plots design with three replications. The horizontal plots contain three N levels, ie., 120, 150 and 180 kg N/ha. The vertical plots include three sowing distances, i.e., 7 cm, 10 cm and 15 cm between plants in the rows. The results obtained showed that application of 150 kg N/ha gave a dried seed yield 5.8 % higher than that of the rate of 120 kg/ha and comparable to that when applied 180 kg/ha. The sowing distance of 7 cm significantly increased seed yields by 5.6 to 16.4 % compared to the distances 10 and 15 cm, respectively. Yield and economic efficiency were the highest with the treatment where N was applied at the rate 150 kg/ha and seed were sown at distance 7 cm within the row.
The key vegetation dominions of dipterocarps forest in Yok Don National Park- a proposal for conservation: Idenitification of dominions of dry forests existing in different topographical sites is a part of the research programme “studying the enrnonment features aiming to set forth measures for management of dry forests within York Don National Park at Vietnam- Cambodia boundary”. The dry forests of York Don National Park occur on poor feralit soil in a wide range of prevailing dimatic conditions. It is shown. that the forests are characterized by the poverty in species composition, low density and structure simplicity. This paper presented some findings on.structural composition of the key dominions and suggested the measures for conservation of dry forest eco- system.
Trichosanthes - a non-timber forest product source worthy of studying and exploiting: The most part of species in Trichosanthes genus (Cucurbitaceae) comprises annual plants, containing pharmaceutical substances. These plants have been used in traditional medicine for treating various diseases, induding diabetes. In the last years many other compounds have been discovered in the Trichosanthes, such as anpha and beta-kirilowin, which have therapeutic effects on canker disease. In Vietnam there were found 12 species, some of which are endemic, such as T. baviensis Gagnep. and T. pierrei Gagnep. This paper reported on the result of the recent research works, target of which is to identify therapeutic effects of some cucurbitaceous species newly dicscovered in Vietnam.