An experiment was conducted in Song Hau Farm to study the growth rate and biomass production of Hymenachne acutigluma and Brachiaria mutica planted at different spaces (20 x40; 20 x30; 20 x40cm). Seeds were taken in Song Hau farm. The different spacing was affected on plant height and growth rate of Hymenachne acutigluma, the highest data was found in spacing of 20x40cm. For Brachiaria mutica,  the same results as those of Hymenachne acutigluma were received in spacing of 20x40cm, however there was not significantly found among treatments. The dry biomass and composition of dry matter, crude protein, NDF, ADF and organic matter digestibility did not be affected by different spacings The results suggest that Hymenachne acutigluma and Brachiaria mutica can be planted at space of 20x40 cm.

An excess of algae growth in Artemia ponds usually causes severe problems such as surplus feed, lack of oxygen, high NH3 concentration and decreasing water quality. Experimental results from 21 soil bottom ponds showed that, there was a close correlation between the content of labile organic nitrogen and amount of mineral N supplied from  the soil bottom pond (R2 = 0,71, P < 0,0001) within 7 days after incubation. There was also a correlation between the mineral N and the quantity of organic mater in soil ( R2= 0,61, P< 0,0001). The correlation between the soil respiration and amount of mineral N ( R2 = 0,65, P< 0,0001) within 7 days after incubation as well as  the C/N ratio ( R2= 0,67, P< 0,0001) were also found with weaker significances. The mineralization of organic N in soil was not related with pH, EC, and total N in these saline soils high in pH, therefore labile organic nitrogen can be used as a good parameter to predict the eutrophic environment related to algae bloom in Artemia ponds.

Agents with a-glucosidase inhitbitory activity have been useful as oral hypoglycemia in patients with type 2, non-insulin dependent, diabetes melitus. Some extracts of different solvents from the seed of Momordica charantia L. were investigated. Preliminary results showed that the alcohol extract gives the greatest -glucosidase inhitbitory activity (IC50=31,25 àg/ml); chloroform extract is weakly and the etherpetroleum extract is inactivity.

Evaluating factors affecting of land use systems and choosing promised land use types in the socio-economic and environmental context at the local area are a firm basis for land use planning. From such requirements, the research of evaluating the effectiveness of the indentified factors on land use systems at Song Phu village was done to applying land evaluation (FAO, 1976) for physical land evaluation, and to identify the input-output factors that affect the effectiveness of the land use systems. The analysis of these land use systems was done by using the input and output factors with Primer software to show the two different farmer groups at the study area and evaluating the effect of the set of input?output factors on the livelihiood of the groups of farmers.

The natural prevalence of white spot syndrome virus (WSSV), monodon baculovirus (MBV), yellow head virus (YHV) and gill associated virus (GAV) infection in 1253 shrimp postlarvae (Pls) batches was investigated. The prevalence of YHV, GAV, WSSV and MBV were 1.4%, 17.3%, 7.8% and 39.4% respectively. The prevalence of YHV, GAV, WSSV and MBV infection in Pls from theMekongRiverDelta was significantly higher than from the central region. The prevalence infection of tested viruses fluctuated according to sampling month and had no clear trend of infection. About 40.6% of sample was negative with 4 tested viruses. Whereas, 45.4 % was infected by one and 10.1 % was co-infected by two or three viruses. Co-infection of GAV and MBV was the highest  (51,2%), following by WSSV and  MBV (22%),  WSSV, GAV and MBV (8.7%) and GAV, YHV and MBV (2.1%).

An experiment was conducted to study the effect of different nitrogen fertilizer levels (30; 50 and 70 N kg/ha) on growth and biomass production of Paspalum atratum and Macroptilium lathyroides. For Macroptilium, different nitrogen fertilizer levels did not affect on growth rate, plant height, fresh and dry biomass production. However, there was a trend to increase biomass yield of Macroptilium on treatment of 50 kg N/ha as compared to the others. For Paspalum, growth rate and plant height at 60 days after planting were affected by nitrogen levels. The highest value was found in treatment of 50kg N/ha as compared to treatment 30 and 70 kg N/ha. Fresh and dry biomass production of the treatment of 50 kg N/ha were slightly higher than those of 30 and 70 kg N/ha, although there was no significant difference among treatments. Different levels of fertilizers did not affect the composition of protein, NDF, ADF and organic matter digestibility of two feed plants. It is suggested that using 50 kg N/ha can give high biomass production for both Paspalum and Macroptilium.

From the n-butanol extract of dried Artichoke (Cynara scolymus L.) flowers, one flavonoid (apigenin-7,4?-dimethyl ether) and one sterol glycoside (?-sitosterol-3-O-?-glucopyranoside) were isolated.   The structures were eluciated by modern spectrometric methods: 1H-NMR, 13C-NMR, COSY, HMBC, HSQC, DEPT and MS.

Assessment of distribution of aquatic organism in the biodiversity zone (BDZ) of 184 enterprises of forestry and fishery  (EFF) was carried out from March 2003 to December 2004 with quarterly sampling at 6 stations. It was found 159 species of phytoplankton include 123 diatom, 15 green, 11 blue green and 10 dinoflagellate species, 43 zooplankton species consist of 2 freshwater cladoceran, and  34 species of zoobenthos contain 15 polychaetes and a insect larvae. Zooplankton density ranges from 800 ? 202500 ind./m3, but there are no significant differences between stations (P>0.05). On the 5th station, the zoobenthos biomass was highest on March and December of 2003 (423.0744 and 27.1698 g/m2 respectively). The 6th station was different from the others because of being  affected by the shrimp farming system around.

An efficient micropropagation protocol was developed directed from shoot tip of burdock (Arctium lappa L.). The excised shoot-tip were cultured on MS medium containing  benzyladenine (BA) for the study of shoot induction. The best medium for shoot induction growth was BA 1 mg/l.  Shoots were rooted most effectively in naphthaleneacetic acid (NAA) 10 mg/l.  All rooted shoots were transplanted in subtrates.

Improving the peel colour of ?Hong? mandarin is, important to enhance an appearance and consequently its commercial value.  The experiment was arranged in a randomized complete block design with five treatments (control, 25, 50, 100 and 200 ppm ethephon) and  three replications, each replication equal to one tree. Two weeks before harvesting, treatments were sprayed with ethephon.  When ripening, fruits were harvested and stored in Plant Physiology laboratory, Cantho University, from December 2004 to March 2005.  The results showed that treatment with 100 ppm ethephon degreened effectively ?Hong? mandarin peel.  Furthermore, the treatment with 100 ppm ethephon had almost no effect on the fruit quality indexes (e.g., 0Brix, total sugar content, pH, vitamin C content) and extended  the postharvest shelf life of ?Hong? mandarin.

The Kintoki ginger was transplanted fromJapanand cultivated in Lam Dong, Dac Lac and Phu Yen provinces.  The content of essential oil changes from different provinces (0,50%  in Lam Dong; 0,24%  in Dac Lac and  0,32%  in Phu Yen). The volatile oil has been studied by the combination of GC and GC-MS.  The main components are zingeberen, b-bisabolene, b-sequiphellandrene depending on the material sources. Three compounds were isolated from an ethyl acetate extract.  One of them was identified such as ?-sitosterol-3-O-?-glucopyranoside.

Aseptic seedling in period of 3-4 weeks old in nursery bed were cultured on MS medium supplemented with N6-benzyladenin (BA) and kinetin (3-5 mg/l). Multipleshoots arose from cotyledons of explant. The shoots were transferred to MS medium supplemented with indolbutyric acid (IBA), Phloroglucinol and active charcoal  for root formation.  Induction of rooting (50%) was achieved by transferring the shoots to the MS medium containing 0,2 mg/l BA with 2 g/l of active charcoal.  Rooted plantlets were easily acclimatized by transplanting to a pot with mixture of husk-ashes and coconut fiber muck (1:1, v/v) and then covered with polythene bags for a week.

Four levels of K/N ratio from 0.6 to 1.5 were designed in the field with combination organic fertilization and sediment munching around their capony ground. From the protocol, humidity and nutrial status at root zone were optimal for root re-establishment after water stress for flowering control. Fruit size and quality were improved manifestly. Applied an exceed quantity of potassium at the flowering time could not diminish the symptom but also cause ?luxury consumption? dued to death of root system.

This paper devotes to find out and measure the household profitability and scale efficiency in the two selected farming patterns in Cho Moi District, AnGiangProvince. Along with this, the author tries to make the conclusions from the findings more valuable by taking the comparisons of the scale efficiency between the two selected patterns. For the cross-sectional data obtained for the 2004/05 agricultural year, the Data Envelopment Analysis (DEA) and Cost-Benefit Analysis(CBA) approach are used to estimate the household scale efficiency and profitability, respectively. The empirical results indicate that farmers with crop rotation pattern are more profitably efficient than farmers with continuous rice pattern. The scale efficiency of the farmers with crop rotation are also higher than that of farmers with continuous rice pattern.

The samples of alcoholic starters, water resource and rice wine were collected and analyzed as well as information of the small scale production of rice wine in Xuan Thanh was also obtained; contributing to promote a developed way in production of qualified final products in rice wine processing. Total mould, yeast and bacteria counts were 6,3-8,5; 5,8-8,3 and 5,6-6,4 log CFU/g of dry weight starter, respectively. A total of 83 strains, comprising 48 moulds and 35 yeasts, was isolated from 14 different collected starters. In general, the local production of rice wine is prepared at home-scale and uncontrolled conditions, resulting in low yield and variable quality of wine. Although some wines can be appreciated in sensory evaluation more or less, most of them are not approved based on the national standards for qualified fermented beverages, particularly the presence of  high contents of aldehyde, ester,? The samples of water resources that are used in the winemaking have a microbiological problem, e.g. high contents of total coliforms.

A greenhouse experiment  was conducted  to examine the possibility of increasing available N on acid sulphate soils (ASS) at Hoa An Can Tho  when biogas sludge and lime were applied. The nonacid alluvial rice soil at Cai lay Tien Giang was used as the control.  Rice was grown in each pot containg 1 kg soil. Treaments were: soil incorporated with (1) biogas (250mgN/kg), (2) urea (250mgN/kg), and with and without lime (10T/ha).  Biogas and lime were incorporated at 4 weeks before sowing and urea was applied 2 days before sowing.  N-NH4 was analysed before sowing and  at 6 weeks after sowing.  N uptake in plant determined at 6 weeks after sowing. Results showed that incorporation of biogas increased N-NH4+ in non acid alluvial soil and ASS with and without liming.  N-NH4  in soils was correlated with N uptake by plant. Therefore N-NH4 in soil can be used as an index for evaluating N supply  from soil.

Two studies were allocated according to a complete block design with three replicates. In the first experiment, there were five species of grasses as elephant grass (Pennisetumm purpureum), Panicum maximum, Paspalum atratum, Ruzi grass (Brachiaria ruziziensis) & sweet sorgho (Sorghum bicolor) were planted. There were three leguminous plants as tropical Kudzu (Peuraria phaseoloides), Macroptilium lathyroides & Stylosanthes gracilis were used in second study. All treatments were planted in a space of 20 x40cm & applied no chemical fertilizer. Samples were harvested at 60 & 45 days after planting for grasses & legumes, respectively, & analysed for dry matter (DM), crude protein (CP), ether extract (EE), acid detergent fibre (ADF), neutral detergent fibre (NDF), in vitro organic matter digestibility (IVOMD), non fibre carbohydrate (NFC) & metabolisable energy (ME). The variation in dry matter, crude protein, fibre components, energy content, or organic matter digestibility is affected by species, stage of plant maturity. The purpose of the study is to describe the variation in composition & nutrient values among feed plants & to identify those factors contributing to this variation may be helpful to individual producers & nutritionist in supplying feed plants to animals.

Histological studies on the ability of systemic acquired resistance (SAR) of benzoic acid, copper chloride and chitosan against rice blast disease were conducted in 2005 to evaluate the ability of SAR of these chemicals when challenged with a race of Pyricularia grisea encoded 103.4 based on cellular reaction and H202 accumulation. The experiments were carried out with completely randomized block design on susceptible cultivar 0MCS2000 and resistant cultivar MTL265 used as a positive control. The susceptible cultivar was induced by seed soaking with either benzoic acid (0.5 mM), copper chloride (0.05 mM) or chitosan (200 ppm) for 24 hours before incubation and sowing and challenged with the concentration of  50,000 spores /ml at fifth-leaf stage. Samples were collected at 24 and 48 hours after challenge (hac) for observation of cellular reaction and 0, 4, 8, 12, 16, 18, 20, 24, 36, 48 hac for observation of H202 accumulation. Results showed that benzoic acid, copper chloride and chitosan had ability of SAR by induction of fluorescent epidermal cells, fluorescent cell walls and H202 accumulation.

A Gas chromatography (GC)-Electroantennogram detector (EAD) analysis of the C. litchiella pheromone extract resulted in two EAG-active components, denoted component I and II, with the EAG-intensities and retention times (Rt) as follows: 43 ?V at Rt 15.60 min and 264 ?V at Rt 16.14 min, respectively.  In GC-EAD analyses of the authentic samples of C16 straight chain compounds, (10Z)-10-hexadecen-1-ol and (7Z,11Z)-7,11-hexadecadienyl acetate eluted at the same retention time, 15.60 min, with the pheromone component I.  However, the EAG-response of (7Z,11Z)-7,11-hexadecadienyl acetate (288 ?V) was much stronger than that of (10Z)-10-hexadecen-1-ol (183 ?V).  Generally, among analyzed compounds, male antenna most strongly responded to acetates. Meanwhile, alcohols and aldehydes showed weak or no EAG-activities.

Temporary Immersion Bioreator (TIB) is an efficient culture technique, which is applied on many plant species, aimed at a rapid proliferation of large scale plantlets with high quality.  In order to apply this new technique to propagation of, the results showed that: (1) The trial of effects of Benzyl Adenine (BA) and a combination of BA and Naphthalene Acetic Acid (NAA) on growth medium revealed that liquid MS medium supplemented with 2 ppm BA yielded a stable multiplication rate.  It was thus, selected for further experiment by using TIB; (2) The trial of effects of TIB with different amount of filters and culture conditions on plant growth indicated that a TIB (1 l volume) equipped with 2 microfilters and placed in the nethouse conditions could reach the best multiplication rate.  In average, from one original shoot, there are 42 billions of new shoots can be produced per year.  Therefore, the multiplication rate is 90 folds higher than other methods of micropropagation.

This study was conducted to aim at improving the post-harvest quality and extending the storage life of ?Hong? mandarin in order to reduce a retaining matured fruits on the tree and decrease post-harvest losses. The experiment was carried out Lai Vung district, Dong Thap province. After the fruits reaching a full mature, they were harvested, stored and chemically analyzed at the lab of Plant Physiology, CanthoUniversity, from 1/2004 to 6/2004. The results showed that treatment with GA3 at concentration of 10-20 ppm as pre-harvest sprays two months before harvesting effectively delayed fruit ripening, prolonged their storage life up to four weeks in ambient condition (28°C, 68% RH), and the quality of treated fruit was still acceptable. GA3 at concentration of 10-20 ppm also induced more shining fruit, high color value, low weight loss ratio, and almost stable of quality indexes throughout the post-harvest storage.

One flavonoid cynaroside (luteolin-7-O-b-glucopyranoside) was isolated from the ethyl acetate extract of dried Artichoke (Cynara scolymus L.) fresh leaves which is planted in Da Lat.  The structure was eluciated by modern spectrometric methods: 1H-NMR,13C-NMR, COSY, HMBC, HSQC, DEPT and MS.

Four field experiments were carried out to evaluate the effects of Gluconacetobacter diazotrophicus and Pseudomonas stutzeri on sugarcane yield and concentration of sugar in sugarcane (Saccharum officinarum L.) cultivated on alluvial soil of Hau Giang province in cropping season (2005-2006). The results showed that the biofertilizer making Gluconacetobacter diazotrophicus and Pseudomonas stutzeri in peat-sugar-byproduct-carrier increased the yield component and sugarcane-yield and these were the same as sugarcane applying 200 kg N and 90 kg P2O5 ; application of the biofertilizer for sugarcane cultivation reduced 150 kg N (326 kg urea) and 90 kg P2O5 (600 kg superphosphate) and the farmers saved 2,493,000 VN đong/ha

Low cost micropropagation procedure for vetiver (Vetiveria zizanioides) was developed. A liquid MS medium supplemented with 2-4 mg BA.l-1 of medium yielded the best multiplication, with average 8 new shoots during a culture interval of 6 weeks. Proliferation and rooting stage in vitro could be carried out under the natural ambience of a nethouse instead of growth chamber conditions. No statistical differences were observed between the two environmental conditions for propagation and rooting, and survival cluster after ten weeks of acclimatization approximately 100%. Nethouse plants were assessed to be about 22% cheaper to produce than growth chamber plants.

The study toxicity of molluscicide Deadline bullets 4% (DB), Helix 500WP (HL), and Osbuvang 800WP (OS) on juveniles snakehead (Channa striata) and climbing perch (Anabas testudineus) was conducted to determine the 96-hLC50 and the effects of sublethal concentrations on oxygen consumption (OC), critical lethal dissolved oxygen level (CLDOL) and time required for death (TRFD). The 96-hLC50 for C. striata was 30, 151 and 187 mg/L for DB, HL and OS, respectively while that of  for A. testudineus was 43, 162 and 180 mg/L, respectively. Snakehead increased OC at the concentration of 0.02, 0.01, and 0.1 fold of the 96-hC50 for DB, HL and OS, respectively whereas climbing perch increased at 0.1, 0.02, and 0.01 fold of the 96-hLC50 in the same order. CLDOL of these species were increased with increased concentrations of molluscicides. However, TRFD was shortened as increased concentration of molluscicides unless DB didn?t cause effect on TRFD in A. testudineus. The study indicates that using OS was not created risk for C. striata or A. testudineus if water level in the rice paddies³ 10 cm.  

From the crude alkaloid extract of the dried leaves of Phyllanthus amarus Schum.et Thonn (Euphorbiaceae), isobubbialine, a securineage alkaloid, has been isolated. The structure of this compound has been elucidated by means of UV, IR, MS and NMR spectra as well as comparison with those of published in literature.

An Giang province is flooding area inMekongDelta.  Formerly, natural aquatic resource was plentiful both species and production.  Nowadays, production of fish was decreased because of many causes.  For this reason, surveys aquatic status; the reason decreased aquatic resource and awere of people about aquatic resource conservation are very necessary.  Results of survey at Chau Phu district, An Giang province showed that people caught fish mainly in the flooding reason. They caught in the field which had many fishes.  Fishing gears was very diversified so species were caught very diversified.  Production decreased much because people used exterminative gears,  fishing at small fish? Besides, their awareness about aquatic protection policy is not good so aquatic resource was used excessively.