Study aims to assess the ability of improving the acid sulfate soils, increasing soil fertility and rice yield in greenhouse conditions. The experiment was conducted in greenhouse, Winter-Spring cropping season 2012-2013 at Can Tho University. Local rice variety Nui Voi 1 (NV1) was used, which is grown on strongly acid sulfate soil (Epi Orthi Thionic Gleysols) in Hoa An, Hau Giang. Steel lag fertilizer was calculated on the basis of the capability to completely neutralize the acidity in the soil. The amounts of steel lag needed to neutralize acidity as dose one and a double dose. Results showed that in the treatments with steel slag, rice growth was better than the control compared with no steel lag treatments in the both doses, however there was not significant different between 2 doses.

Acid sulphate soil is a problem for agriculture. In particular, the impact of saltwater intrusion makes farming difficult, directly affecting the lives of farmers and sustainable economic development. This study was carried out in the low-lying areas located in the west of Hau Giang province to assess the adaptive potential of land use types for the acid, salt intrusion in dry season. The research collected soil and water samples for analyzing indicators of acidity and salinity. The results showed that acid sulphate soils in the study area mainly occur in shallow layer (0-50 cm); intruded saline water varied in salinity content and had different duration. The maximum salinity intrusion duration recorded was 3 months. Using the methods for land evaluation according to the FAO (1976) indicated that the study area could be divided into 5 areas with adaptive capacity from medium to low due to the effects of salt water and acidity. This study contribution was to support local authorities in identifying suitable cropping patterns to produce more efficiently, highly adapting to saltwater intrusion conditions.

In the Mekong Delta, the rice crop constantly changes, it is difficult for agricultural management. To determine the distribution rule and the change of rice crop calendar, the study was made to monitor the distribution of rice crop and assess the change of rice crop calendar in the Mekong Delta from 2000 to 2010. MODIS images (MOD09Q1) is used to calculate NDVI values and to build the rice crop map of the rice-growing areas for each year and then overlay the maps to evaluate the change over year. The results showed that the distribution of rice crop calendar can be divided into two typical seasonal groups, there are the areas of freshwater sediment and the rain-fed salinization. In freshwater sediment areas, the main rice cultivation are triple-cropped irrigated rice, double-cropped irrigated rice and rice ? vegetables. In the rain-fed salinization areas, the main rice cultivation are double-cropped rain-fed rice, single-cropped rain-fed rice and single-cropped rain-fed rice /shrimp. The change of rice cropping partern on two areas affected by weather conditions, floods and the dike system. The results of assessment showed that the accuracy of data predicted in the freshwater sediment areas was higher than in the rain-fed salinization.

This study is to apply the Oryza2000 model to simulate the rice yield of SocTrang province. The results of simulation was correlated with field observations from 9 locations in three seasons (Winter-Spring; Spring-Summer and Summer-Autumn) of 2012-2013.  Weather, crop management, water management and fertilizers uses data are also collected as data sources for the model. The results showed that the rice yield simulated from Oryza2000 model has very close correlation with field conditions for Winter-Spring and Summer-Autumn rice seasons, (r = 0.77 and r = 0.84), while there was no correlation for Spring-Summer season, it can be due to water regime and soil salinity constraints in this season.

This study aimed at investigating the effects of amending green manure (Sesbania sesban) and combining with lime on soil nutrients and the yields of rice and maize that were grown on acid sulfate soil. The experiment was set up in a green house and was designed with complete random. There were three treatments and four replicates designed for each crop consisting of (1) Sesbania amendment, (2) Sesbania amendment in combination with liming, (3) control without either Sesbania or lime amendment. Sesbania was sown and the biomass was incorporated directly into soil after 20 days. The fresh Sesbania biomass was approximately 8-10 tons/ha. One ton of lime in the form of CaCO3 was applied before sowing rice or maize crop. During the growth period, rice and maize crops were applied with nitrogen, phosphorus (P2O5) and potassium (K2O) with doses of 100-60-30 for rice crop and 150-60-90 for maize crop. The results showed that growing and incorporating Sesbania biomass into acid sulfate soil increased soil total N and available (NH4+, NO3-) (p < 0.05) as well as the yields of rice and maize (p < 0.01). The benefits of amending Sesbania sesban on soil nitrogen availability and crop yield were enhanced if lime (CaCO3) was applied for both rice and maize.

Aims of the study were to investigate the nitrogen distribution in ion forms of NH4+ and NO3- at different depth upon time, and to study the effect of NPK deep placement technique and urea-nBTPT on rice yield. Field study was conducted with 10 treatments, including three types of N fertilizer and three N fertilizer rates (60, 80 and 100 kg N/ha). Results indicated that concentration of NH4+ in floodwater and in soil (0 - 3 mm from surface) was higher in broadcast application prill urea treatment and urea-nBTPT treatment than NPK briquette treatment. Deep placement of NPK briquette treatment had much higher concentration of NH4+ and NO3- at 5 cm and 10 cm depth from soil surface; and had much lower this concentration in floodwater. Both NH4+ and NO3- concentration were high at 5 cm and 10 cm from placement site. Plant and grain N uptake were higher in NPK briquette and nBTPT-treated urea fertilizer than in urea fertilizer at the rate of 80 kg N/ha. Crop yield and agronomic efficiency were slightly higher in NPK briquette and urea-nBTPT than prill urea although differences were not statistically significant.

The aim of this study was to evaluate the effect of organic and inorganic fertilizers on the improvement of soil fertility in terms of chemical and biological soil properties of coconut-cacao intercrop orchard. Treatments were arranged in randomized complete block design: (1) High dose of inorganic fertilizer as farmers? practice (628- 327-64 g/plant/year); (2) Recommended inorganic fertilizer (200-200-150 g/plant/year); (3) Balanced inorganic fertilizer (200-70-300 g/plant/year); (4) Organic fertilizer 24 kg/plant + 50% balanced inorganic fertilizer; (5) Organic fertilizer 24 kg/plant + 75% balanced inorganic fertilizer. The results indicated that organic amendment in combinination with lower dose of balanced inorganic fertilizers led to increase of soil organic matter, labile soil organic C, labile organic nitrogen and available phosphorus in soil, significant difference compared to high dose of inorganic fertilizers in farmers? practice. Similarly, soil biological properties as the total number of fungi and total number of microbial density, activities of phosphatase and catalase enzyme in the soil were increased significantly at 30 days and 90 days after organic amended. Therefore, reducing from 50%-70% level of fertilizer application from farmers, adding organic fertilizer with 12 tons /ha resulted in improving of soil nutrients and enhancing soil microbial activities in coconut-cacao intercrop orchard.

The field study has been conducted in saline water instrusion area at Long My district - Hau Giang province during wet season 2014. The objective was to determine effect of CaO, Brassinosteroid and KNO3 in improving rice yield and growth under saline water irrigation condition. There were 7 treatments arranged in randomized complete block design with 3 replicates. Rice was irrigated saline water at 5, 10 and 17 days after sowing with concentration of 3?. The results showed that spray KNO3, CaO boardcasting or spray Brassinosteriod before saline irrigation has promoted the accumulation of proline in rice at 45 and 70 days old after sowing. Also, Brassinosteriod spraying or KNO3 spraying maintain good height through the stages of rice growth. Rice growth was improved through the effective maintenance on the number of panicle per m2, number of filled grains/panicle lead to increased yields after KNO3 spraying or CaO boardcasting combination Brassinosteriod spraying. Electrical conductivity (ECe) of the soil increased highly at 45 days after sowing.

Application of inorganic fertilizers with high dose and unbalances has led to the decline of soil fertility in-terms of physicochemical, biological properties of fruit orchards. The objective of this experiment was to determine the long-term effect of organic compost amendment in improving soil properties and fruit yield. The experiment was conducted in six crops of rambutan with three different composts including sugarcane filter mud, biogas sludge and vermi-compost. Compost was amended at a rate of 18 kg.plant-1 combined with a low dose of inorganic fertilizers in comparison with farmer?s practice. The results showed that application of three kinds of compost with low and balanced nutrients of inorganic fertilizers resulted in significant increase of soil pH, soil organic matter content, soil available nitrogen and phosphorus, exchangeable K and calcium, base saturation percentage, soil structure stability, bulk density, soil respiration in comparison to farmers? practice (p < 0.05). From the third crops after organic amendment, fruit yield was significantly increased, 60 ? 136% compared with those in farmers? practice. Fruit weight was higher by measuring the number of fruit per kg in treatments supplied with biogas sludge and sugarcane fillter mud. The results need to be recommended to farmers for using compost and reducing inorganic fertilizers to improve soil fertility and to enhance rambutan fruit yield and to increase income for farmers.

This research "Treating rice straw on field using probiotics in the Spring - Summer crop at Cai Be district, Tien Giang province? aimed at (i) investigating the on-field decomposition of rice straw using probiotics and (ii) evaluating the effect of on-field decomposition of rice straw on the soil chemical properties. The experiment was carried out in the farmer?s field in a randomized complete block design with 5 treatments of treating rice straw and 3 replicates: 1) Rice straw + Biomix, 2) Rice straw + Trichoderma ? DT, 3) Rice straw + AT compost, 4) Rice straw incorporated into the tillage soil and 5) rice straw burning on field (control). The results showed that straw residues after applied with probiotics such as Biomix, Trichomix-DT and AT attained from 26.89% to 27.99% of the initial mass and 34.39% with the controls.  The ratio C/N in the rice straw residue was the lowest in the treatments applied with Trichomix-DT 40,27. Rice straw decomposition of Biomix treatment was found about 50 days; for Trichomix-DT and AT treatmnet about 60 days; without probiotic treatment about 70 days at the control. The Navailable amount in soil of rice straw and Trichomix-DT treatment was highest content contain 23,70 mg/kg; Three bio- products: Biomix, Trichomix-DT and AT compost can be applied to process rice straw, however Trichomix-DT and AT compost can be used to supply nutrients (N,P) and to improve  C/N ratio in soil.

The study were aimed to analyze income from the different cropping systems for selecting suitable systems at low saline area at Ba Tri district - Ben Tre province. The testing cropping systems were water melon-rice-rice, okra-rice-rice and corn-rice-rice compared to triple rice system. Soil and irrigation water samples were taken in these systems to investigating changes in pH and EC from 4/2012- 6/2013. Results showed that saline intrusion has raised pH and EC of irrigation water in the dry season. pH and EC in soil was lower and was not much varied during investigated time. The okra-rice-rice cropping systems gave highest income. The water melon-rice-rice system showed lower income, but was the promised system which can be considered as another choice for farmer. The corn-rice-rice system gave lowest economic income, but it had low cost, therefore had low risk for farmer. The rice-upland crop alternative systems gave higher yield than triple rice cropping systems. Using certified new rice variety, organic fertilizer, and balance NPK fertilizer resulted in the increase of rice yield and farmer?s income, which should be considered.

Objectives of this study were (i) to determine NPK concentration and ratio C/N of rice straw compost inoculated with Trichoderma, nitrogen-fixing bacteria Azospirillum lipoferum and phosphorus soluble bacteria Pseudomonas stutzeri; (ii) to evaluate the effects of above compost on rice growth and rice yield. The experiment was established in a randomized complete block design including five compost treatments NT 1: rice straw inoculated with Trichoderma (control); NT2: rice straw inoculated with Trichoderma + nitrogen fertilizer + phosphorus fertilizer; NT3: rice straw inoculated with Trichoderma + phosphorus fertilizer + phosphorus soluble bacteria Pseudomonas stutzeri; NT4: rice straw inoculated with Trichoderma + nitrogen fertilizer + nitrogen-fixing bacteria Azospirillum lipoferum; NT5: rice straw inoculated with Trichoderma + nitrogen fertilizer + phosphorus fertilizer + nitrogen-fixing bacteria Azospirillum lipoferum + Phosphorus soluble bacteria Pseudomonas stutzeri. Results showed that rice straw compost inoculated with nitrogen-fixing bacteria gave highest nitrogen content. Rice straw compost inoculated with Triochoderma and nitrogen-fixing bacteria Azospirillum lipoferum gave lowest C/N ratio (15.2), while the C/N ratio of rice straw compost inoculated with only Triochoderma was higher (19.65) after 7 weeks. Application of rice straw compost inoculated with Triochoderma and nitrogen-fixing bacteria Azospirillum lipoferum improved rice height, rice yield components including filled grain percentage, 1000-grain weight. This resulted in higher rice yield (0.49 kg m-2) in this treatment in comparison with the treatment of rice straw compost inoculated with Triochoderma (0.41 kg m-2).

An analysis of the correlation between water quality indicators and socio - economic values were done based on available data of surface water quality and socio-economic indicators of Can Tho and Soc Trang from 2005 to 2009. The surface water quality parameters used include DO, BOD5, COD, pH, TSS, Fe, NH4-, NO2-, NO3- and coliform and ten socio ? economic indicators were population density, the number of industrial establishments, commercial ?service, area of land for rice cutivation, rice production, area of land for aquaculture, aquaculture production, area of land for vegetations and number of livestock and poultry. The results showed that an increase in population density, industrial and commercial sectors, and livestock production resulted in increased levels of organic matter parameters in river/canal. In contrast, rice and aquaculture production had positive correlation with the concentration of TSS, pH and nitrogen parameters.

An Giang is one of the provinces with the highest rice production in the Mekong Delta and in the country. Every year, under the impact of floods, climate change and the warming of the earth's crust has significantly affected the situation of rice production in the province. Therefore, assessment the level of vulnerability to rice production under the impact of climate change needs to do to determine the vulnerability area of flooding, saltwater intrusion in the province. Based on Southern Irrigation Planning Institute`s the scenarios of sea level rise and the scenarios of saline intrusion to evaluate the vulnerability area on the current of the agricultural land use in province. Result of the study showed that: vulnerability of flooding, saltwater intrusion are shown on the map with the different levels of vulnerability for each climate change scenario. And vulnerability factors were partially or even a large area obstruct of rice farming in An Giang, the area of 02 rice crops, 03 rice crops in province has been affected differently in various climate change scenarios. These results are very important basis for local to adjust appropriately and timely in land use to deal with climate change.

For sustainable development, selection of land use for agricultural production often requires the compromise of social, economic and environmental purposes. Given different opinions, values and attitudes from different stakeholders, selection of certain land use results in unavoidable conflicts. Therefore, the study was conducted with the aims of improving existing land use systems, leading to changes of agricultural structure towards sustainability. The study was carried out in three agro-ecological zones (fresh, brackish and saline water) in Bac Lieu province. Data were collected via the Participatory Rural Appraisal (PRA) Method, household interviews. The mDSS (Decision Support System) model was used to optimize land use decision. It is a combination between model DPSIR framework (Driving forces, pressures, State, Impacts and Responses) and FAHP-GDM method (Fuzzy Analytical Hierarchy Process-Group Decision Making). The results showed that the important factors affected to farming systems were water resources, diseases, available capital of farmers, technical assistance and capital benefit. The application of the proposed land use types in large scale depends on hydrological conditions and actual farmer's socio-economic context.

The objective of the study is to evaluate the result of simulation leaf area index of Oryza2000 model with LAI observation in SocTrang province. Weather data, crop management, water management and fertilizer use data are also collected as data sources for the model. LAI observation will be determined using an indirect leaf length ì width and scanning method. With this method, length (L) and width (W) of all leaves in the sampling area will be measured whereas small number of leaves will be scanned to develop a regression-based slope to convert measurements of leaf L and W into leaf area for the entire plants in the sampling area. The results showed that the LAI simulated from Oryza2000 model has very close correlation with LAI observed for Winter?Spring, Spring-Summer and Summer?Autumn rice seasons, (r2=0.85, r2=0.6 and r2=0.62). Low leaf area at the beginning of the growth period and increased rapidly in the flowering period.

The purposes of the study ?Effectiveness of using rice fields to treat polluted water of catfish (Pangasianodon hypophthalmus) pond? were to recycle nutrients in wastewater from fish ponds for rice irrigation, reduce inorganic fertilizer application, and decline the discharge of fishpond wastewater to water bodies. The experiments were carried out in farmer?s rice fields including four treatments: (1) freshwater and NPK fertilizer were applied to the rice field. (2) waste water from fish ponds and NPK fertilizers were applied to the rice field. (3) waste water from fishponds and NPK fertilizers (two third of the weight used in treatment (1). (4) waste water from fish ponds  and only potassium fertilizer were applied to the rice field: The results showed that using waste water from fish ponds for irrigating rice field reduced nutrients effectively in all treatments. Total Kjeldahl nitrogen (TKN) removal performance by rice field was 63.66% in treatment (2), which was lower than in treatment (3) (67.5%). The highest removal efficiency was 73.09% observed in treatment (4). Similarly, the highest treating performance of total phosphorus (TP) was 84.58% in treatment (4) and lowest in treatment (2) (78.41%). Besides, the use of waste water from fish ponds for irrigating rice fields could reduce at least one third the amount of fertilizer applied while maintaining the yield of rice.

The Mekong Delta is the key national food production, accounts for more than 53% of the total rice production and contributes 90% of national rice export. However, the rice pests and pest outbreak was affecting the productivity and yield of rice and very difficult to manage and predict. Therefore, the study focused mainly on tracking, monitoring the progress of rice showing and the rice cropping stages in the locality for early warning the occurrence of pest and disease. The study was based on MODIS remote sensing to analyze the Vegetation Index (NDVI) to support tracking down the rice showing progress for early warning the occurrence of pest in the Mekong Delta, which assist the managers to develop the management strategies effectively and timely. Results showed that satellite images of MODIS can be used to generate the rice cropping stages and pest occurrence status. There was a close correlation between vegetation indices with different rice cropping stages at high accuracy (R2 = 0.83).

The aim of this study was to assess the effect of organic fertilizer and plastic cover on some selected soil biological properties such as total microorganisms and enzyme activities in mangosteen orchard. The experiment was investigated through soil analysis of five treatments: (1) farmer practice of inorganic fertilizer application without plastic cover; (2) Recommended inorganic fertilizer combined with compost and without plastic cover; (3) Compost and without plastic cover; (4) Farmers? practice with plastic cover; (5) Recommended inorganic fertilizer, compost and plastic cover. The results showed that compost amendment, balanced inorganic fertilizer and platic cover in early rainy season resulted in highest total microbial density, microorganisms decomposing cellulose and Trichoderma sp. in soil. In addition, catalase, phosphatase enzyme activity were enhanced significantly in comparison to farmers? practice without plastic cover. There was no sinificant difference in ?-glucosidase enzyme activity among five treatments. In general, organic amendment, lower level and balanced inorganic fertilizers with plastic cover content in rainy season resulted in enhance microbial activities in soil of mangosteen orchard.

Saline intrusion has caused remarked drawbacks on agricultural production and the livelihood of local people in Thanh Phu - Ben Tre. Therefore, it needs to study on the balance nutrient amendment and improvement of saline soil properties to increase crop yield and income for farmers. The objective of this study was to investigate the effect of organic fertilizer and lime on improving of some selected soil properties and rice growth. Experiments were established in green house. Soil sample was collected from the fields under shrimp-rice cultivation. In the condition of high saline as submergenced in 6 ppt, compost and lime amendment resulted in exchangeable Na+ amelioration and exchange sodium percentage (ESP). In addition, these amendments significantly enhanced the availability of N, P and K in soil. However, rice could not grow under this high salinity condition. In reducing saline condition to 5 ppt, 5 ton/ha of compost and 0.5 ton/ha lime addition led to increase significantly rice yield component and rice yield. The results revealed that it is necessary to execute the changes on properties of saline-affected soils and rice yield by amending organic matter and lime in field condition.

The study was conducted in laboratory to determine the effect of different levels of soil moisture, inorganic N fertilizer and organic compost amendment on the emission of CO2 and N2O from rambutan orchard soil. Soil samples were taken from the 22 years rambutan orchard in Phu Phung village, Cho Lach district (Ben Tre province). The randomized complete design with eigth treatments and three replicates was used in the study. The results showed that CO2 emission was higher under the soil moisture content of 60% than under the soil moisture content of 40%. CO2 emission in the treatment of inorganic N fertilizer plus sugarcane filter cake compost was higher significantly (p < 0.05) compared to treatments of inorganic N fertilizer. Available N in soil was found high in all treatments applied inorganic N fertilizer plus sugarcane filter cake, and it had significant differences (p < 0.05) compared with treatments applied only inorganic N. However, the N2O emissions in the treatments with sugarcane filter cake compost amendment were less than inorganic N fertilizer application (p < 0.05). In addition, the N2O emission in soil at 40 % moisture was higher than at 60% moisture.

This research aimed at: (i) to determine the effect of on-field rice straw burning on soil chemical properties in Tien Giang province; and (ii) to evaluate the ways of rice straw management on improving the soil environment of triple cropping rice sytem. Soil samples were collected twice before and after burning rice straw and compared with or without burning rice straw on Winter-Spring crop and Summer-Autumn crop. The survey showed that 81.7% farmer burned rice straw on field after harvesting. There was no significant changes in soil physical and chemical properties before and after burning. However, it found that the soil bulk density and EC incresased after burning; total nitrogen (TN), NH4+and cation exchangeable capacity (CEC) decreased after burning rice straw. Without burning rice crop, soil contained high organic matter of 12.29% on the Winter-Spring crop and of 9.24% on the Summer - Autumn crop; soil density (0.77 g/cm3) and total nitrogen (0.27%) were also better than burning rice straw condition. Rice cultivation without burning rice straw or incorporation of rice straw into soil increased soil pH and C/N.

5,636 freshwater snails were collected from paddy fields, ponds, ditches, canals in Vinh Long and Dong Thap provinces. Basing on the classification system of the freshwater snail of Somsak Panha (1982), John Burch (1982), Dang Ngoc Thanh, Thai Tran Bai, Pham Van Mien (1980), 14 species of freshwater snails had been identified, including Lymnaea swinhoei, Lymnaea viridis, Indoplanorbis exustus, Clea sp., Bithynia siamensis, Mekongia sp., Eurysia sp., Adamietta, Melanoides tuberculata, Sermyla sp., Tarebia granifea, Pomacea canaliculata, Trochotaia sp., and Filopaludina martensi. They belonged to 7 families: Lymnaeaidae, Planorbidae, Buccinidae, Thiaridae, Viviparidae, Bithynidae, Ampullarridae. The freshwater snails had high frequency of occurence such as Lymnaea swinhoei (17.09%), Bithynia siamensis (12.74%), Lymnaea viridis (11.43%), Eurysia sp. (9.07%), Tarebia granifea (8.41%), Pomacea canaliculata (8.22%), Melanoides tuberculata (7.75%), Mekongia sp. (7.35%), Indoplanorbis exustus (7.19%), and the snail had low frequency such as Clea sp. (5.61%), Adamietta sp. (3.25%), Trochotaia sp. (1.17%), Sermyla sp. (0.59%), and Filopaludina martensi (0.16%). Remarkably, 13/14 species were recorded as intermediate host of trematoda class infecting human and animals, and Pomacea canaliculata snails were intermediate host of Angiostrongylus cantonnensis (class Nematoda) causing eosinophilic menigitis in human.

In recent years, a lot of ducks have been dead by ?limberneck disease?. The main symptoms of birds are neck flaccid paralysis and wing paralysis and inner eyelids, but there is lack of gross lesion and microbial infection evidence. Botulin (Clostridium botulinum toxin) was suspected to be the cause of this disease. From November 2013 to December 2013, 40 intestinal samples were collected from moribund birds with those symptoms for testing the Clostridium botulinum toxin in mice. The results showed that, 7/40 (17,5%) samples killed albino mice with typical symptoms of limberneck disease and without lesion. Some of dead mice had hemorrhage in lung (5%) and heart (2,5%).

The study ?The prevalence of ectoparasite infestation in domestic dogs in Can Tho city? was conducted from December 2013 to April 2014. Totally, 208 domestic dogs were examined, and 39.42% of them were infested by ectoparasites. Specifically, domestic dogs in Co Do district had higher infectious rate (55.77%) than domestic dogs in Ninh Kieu district (33.97%). Domestic dogs at all age were infected ectoparasites. Raising methods had an influence to the ectoparasitic infectious rate. The ectoparasitic infection rate of free-ranged-domestic dogs was higher than it does in kept dogs, namely the former occupied 42.26%, and the latter was only 22.95%. There was no statistical deference between the prevalence of the ectoparasite infectious rate with regard to sex. In our research, we identified 5 different species including 2 species of ticks: Rhipicephalus sanguineus and Boophilus microplus; 2 species of fleas namely: Ctenocephalides canis, Ctenocephalides felis felis and 1 species belonged to Demodex canis. Among them, domestic dogs were infected mostly by Rhipicephalus sanguineus (25.00%), following by Boophilus microplus with 18.27%, and Demodex canis (9.62%).  In contrast, fleas infected domestic dogs with low percentage. Namely, Ctenocephalides canis and Ctenocephalides felis felis had infectious rate of 3.85%, 1.92%; respectively.

Chicken pancreas, which is an organ involved in many digestion processes, is one of the by-products utilized to extract enzymes. In Vietnam, the amylase and protease, have been applied in many different areas, but these enzymes must be imported from foreign countries with rather high price. This study was carried out to aim at finding out usably extractive methods of amylase and protease from chicken pancreas. The results showed that enzyme extraction method using phosphate buffer solution with pH 7 and precipitated protein by (NH4)2SO4 of 60% saturation, then dialyzed and freeze-dried obtained the most effectively extracted enzyme. Amylase which was extracted from the chicken pancreas worked well at 50oC and pH 7.5. The addition of 0.1% NaCl and 0.05% CaCl2 increased the activity of amylase. Protease was extracted from the chicken pancreas worked well at 50oC and pH 7.6. The addition of cysteine ??0.01% and 0.1 ppm CaCl2 increased protease activity. SDS-PAGE analysis showed the presence of the enzyme ? amylase, trypsin and chymotrypsin in the extracted protein samples. After 90 days storage at - 20oC, the enzyme products still maintained their catalytic activities.

The effects of protein solubility on methane production in an in vitro incubation and the growth rate of lai Sind with two experiments were studied. In an in vitro incubation, the treatments in a 2ì2 factorial design were: protein meal (fish meal and groundnut meal) and source of non-protein nitrogen (nitrate and urea). The results of experiment showed that gas volume, methane production, ammoniac and digestion were significantly different between treatments of experiments (p

A study on isolation and identification of duck hepatitis virus was performed on 25 liver samples from suspected viral hepatitis ducks collected in Hau Giang by inoculation on duck embryos and duck embryo fibrobasts. The results showed that all of duck embryos were died after inoculation from 48 to 72 hours. Typical lesions of inoculated embryo were stunt embryos with skin hemorrhage and orange or green livers covered with hemorrhagic. The cytopathic effect in embryo fibrobast cells are curled destroyed cell syncytiums and viral plaques. The results  of RT-PCR technique showed that all 25 samples from suspected viral hepatitis ducks contained duck hepatitis virus A genotype 3 (DHAV-3).

Blood samples was collected from 640 cattle in Tri Ton and Tinh Bien districts in An Giang province and tested for the presence of blood parasites by Giemsa-stained thin blood smear method. Trypanosoma was detected by injecting 120 blood samples of cattle to laboratory mice (Mus musculus). Blood-sucking insects and ticks were collected and identified. The results showed that the prevalence of blood parasites in cattle was 18.28%. Cattle at all ages were infected, the infection rate of cattle at

Fifteen samples of Zephyranthes rosea (Spreng) Lindl in different places in the Mekong Delta (Vinh Long, Ben Tre, An Giang and Dong Thap province and Can Tho city) were collected. Their leaves were used for analyzing genetic diversity using RAPD (Random Amplified Polymorphic DNA) markers and testing the antibacterial susceptibilities expressed as minimum inhibitory concentrations (MIC) of eight selected Gram positive and Gram negative strains: Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella spp., Aeromonas hydrophila, Edwardsiella ictaluri and Edwardsiella tarda. Results showed that: Zephyranthes rosea (Spreng) Lindl had genetic diversity and was divided into 5 groups. All of them had effective antibacterial activities against tested bacteria (256 àg/ml ? MIC ? 4096 àg/ml) with the most effectivity was against Escherichia coli (group 4 with MIC= 256 àg/ml and group 1 with MIC= 512 àg/ml), followed by Staphylococcus aureus (group 5 with MIC= 1024 àg/ml), lower effectivity was against Aeromonas hydrophila and Edwardsiella ictaluri (all of them with MIC= 2048 àg/ml).

Through 216 serum samples collected from 3 breeds (Noi, Tau Vang, and Luong Phuong) at 3 fattening periods (2, 4, and 10 weeks after vaccination of, Lasota strain vaccine), the results showed that the geometric mean titres (GMT) at 2 weeks after vaccination were 5.00 log2, 4.37 log2, and 4.29 log2 for Noi, Tau Vang, and Luong Phuong chickens, respectively. After 4 weeks of vaccination, the antibody titres were gradually decreased but still protected Noi chickens from Newcastle disease (GMT = 4 log2). Conversely, Tau Vang and Luong Phuong chickens with the lower GMTs of 4 log2 were not protected from the disease. After 10 weeks of vaccination, 3 chicken species were not protected.

The study was conducted on 36 weaning pigs of Yorkshire x Landrace crossbred group with an initial average weight of 9 kg/ head at Experimental Animal Unit and householders located in Hoa An village, Phung Hiep district, Hau Giang province. All the weaning was allocated to a randomized complete block design with 3 treatments of (i) basal diet (NT1), (ii) NT1 supplied with 300 mg ?-glucan/ head/ day (NT2), (iii) NT3 supplied with 150 mg ?-glucan and 300 mg vitamin C/ head/ day (NT3). After 9 weeks of the experiment, it indicated that (i) supplement of ?-glucan and vitamin C did not affect basic parameters such as body temperature and respiratory frequency of the weaner; (ii) average daily gain (g/head/day) in NT3 was higher than that in NT2 and NT1 (p0.05); and (iv) feed conversion ratio in NT3 was lowest (p

Twenty four lactating sows and their piglets were carried out an experiment of farm in the Cho Lach district, Ben Tre province. The trial was designed as a 2 x 2 factorial experiment with two different piglets? breeds (B) (B1: Duroc x Yorkshire-Landrace and B2: Landrace x Yorkshire-Landrace) and two kinds of complete feeds (F) (F1: 18% CP and F2: 20% CP) were implemented. Results on the breed showed that the total weight, mean live weight and live weight gain of piglets were significantly different (p

The experiment was carried out using a 4 x 4 Latin square on Laisind (Sindhi-Yellow) female cattle at 10 - 12 months of age. Four treatments were made including: no cassava forage supplement (CF-0), 20% dried cassava forage supplement (DCF-20), 20% ensiled cassava forage supplement (ECF-20) and 20% fresh cassava forage supplement (FCF-20) in basal diet of Elephant Grass. The results showed that dry matter intake (DMI) and the digestibility of DM, OM, CP, NDF increased gradually with supplementing of cassava forage (p

To determine some hematological and biochemical parameters of local Muscovy duck (Carina Moschata Domesticus) in Vinh Long province, 52 blood samples of clinical healthy ducks at the age of nine and 23 week were used. The results showed that the blood physiological, biochemical criteria of the tested ducks ranged within the normal range. Total red blood cell counts (RBC), total white blood counts (WBC), haemoglobin concentration (Hb), and packed cell volume (PCV) were 3.18 ± 0.12 (106/mm3), 28.07 ± 3.63 (103/mm3), 11.64 ± 1.34 (g%) and 37.26 ± 4.4 (%), respectively. There were significant differences (p

Ascaris suum is a popular parasitic roundworm that infests pigs resulting failure of health, performance and causing considerable economic losses. Recombinant vaccines have shown promise for prevention of several helminth infestations. Several studies have shown that native protein 16-kilodalton (AS16) which was found in larvae and adult worm intestine, hypodermis, and cuticles can induce antibody responses against A. suum larvae in mice and pigs. In this study, hydrophobicity and hydrophilicity of AS16, which might correlate with antigenicity/immunogenicity characterized by the whole protein, was analyzed by Genetyx version 10.0. Vaccinal effects of recombinant protein AS16 were analyzed in experimental mice BALB/c. The results of this study showed that major epitope of protein AS16 predictably locates within 30G - 60A region and mice intranasally vaccinated with Escherichia coli-expressed recombinant AS16, generated a significant increase in the level of rAS16-specific antibody responses. Findings of this study provide significant reference for vaccine candidate production based on recombinant?epitope expression against ascariasis in pigs.

A total of 2288 blood samples of ducks were collected in 2 areas: Thoi Lai district, O Mon district of Can Tho city and Cao Lanh district, Cao Lanh city of Dong Thap province, and blood-smears were stained with Giemsa method and identified species of Leucocytozoon or Plasmodium according to the method of Pham Sy Lang (2005), Soulby (1999); the necropsy was performed on 78 ducks; and the experimental treatments of blood parasite disease were carried out in 3 duck flocks, using T.CORYZIN and HANCOC medicines. The results showed that the prevalence of hemoparasite infection was rather high at 26.35%, namely the prevalence of infection in Dong Thap province, and Can Tho city was 26.38%, and 26.34%; respectively. Notably, it increased according to the ages of ducks. Leucocytozoon simondi and Plasmodium spp. were detected in collected samples. Leucocytozoon simondi was main species infecting domestic ducks and it has a much higher prevalence than that of the others. Anemia, pale mucosa, stuntedness, green droppings, diarrhea, paralysis of the legs, and sometimes suddenly dead were recorded as the clinical signs of infected ducks. Through necropsy, we also detected hemorrhage and necrosis in lung and liver, enlargement in kidney and spleen of ducks. Both T.CORYZIN and HANCOC are effective after 14 to 21 days of treatment.

A study was conducted on 300 Hisex brown laying hens from 34 to 43 weeks of age to evaluate optimum dietary copper (Cu) levels on production performance, egg characteristics, red blood cell, plasma lipid and egg yolk cholesterol content. The study was allocated according to a completely randomized design into 5 treatments, a basal diet used as the control contained 16.26% CP, 2756 kcal/kg and 17 mg Cu/kg. Four other experimental diets was prepared by addition 40, 60, 80 and 100 mg Cu/kg diets with 15 replicates. Results showed that daily egg production and egg mass were significantly higher in the treatments supplemented with Cu than the control (p

Experiment was implemented using a 4 x 4 Latin square design with 4 treatments. Tannin levels of the treatments increase from 0, 4, 6 and 8 % (dry basis) in diets of 4 male Lai Sind cattles at 2 years of age. Each experiment period was two weeks, 11 days for adaptation and 4 days for collecting sample. The experiment carried out at the Department of Aninal Science, College of Agriculture and Applied Biology, Can Tho University and the cattle farm in Tam Vu, Distrist Cai Rang, Can Tho City. The results showed that digestibilities were improved with supplementation of tanin (p0.05).

From December 2012 to May 2013, 120 samples (43 Su shrimp, 43 Bac shrimp and 34 Rao Dat shrimp) were collected from some markets in Can Tho city to isolate Vibrio spp. bacteria by using ISO/TS 21872-2:2007 standard. The results showed high propotion positive with Vibrio spp. 16,66% (20/120). The rate of Vibrio spp. from Su shrimp, Rao Dat shrimp and Bac shrimp was 20.93%, 17.65% and 11.63% respectively. By chemical tests, Vibrio cholerae (11.11%) and Vibrio fluvialis (22.22%) were found in Su shrimp. However Vibrio cholerae and Vibrio vulnificus were found in Bac shrimp with 40% and 20%, respectively. Vibrio fluvialis, Vibrio cholerae, Vibrio vulnificus were found in Rao Dat shrimp with the same rate (16.66%). Vibrio spp. were sensitive with Doxycyline, Gentamicin, Bactrim, Amoxicillin and Norfloxacinin in antibiotic test. Vibrio spp. were multiresistance with (Ax+Bt), (Nr+Bt) (10%) and (Bt, Ax, Ge)(5%).

A total 120 rice-field rats and 96 rats were collected and necropsied in 3 districts (Thap Muoi, Cao Lanh, Chau Thanh) in Dong Thap provine. The results found that both rice-field rats (Rattus argentiventer) and rats (Rattus norvegicus) were infected helminthes with high infectious rate of 82.50%, and 100% respectively. Through identification and classification, rice-field rats and rats were infected by Nematoda, Cestoda and Trematoda. Rice-field rats were infected by 8 species. Among them, Nematoda had the highest infection rate of 51.67% including Nippostrongylus braziliensis (43.33%), Protospirura muricola (7.50%), Syphacia obvelata (3.33%). Following by Cestoda, it occupied 33.67%, consisting of 4 species: Hymenolepis diminuta (16.67%), Hymenolepis sp (6.67%), Raillietina demerariensis (5.83%), Raillietina celebensis (5.00%). The infectious rate of Trematoda was only 5.83% with 1 species Echinostoma aegyptica. Rats were infected by 6 species of parasites. Among them, Nippostrongylus brazilliensis had the highest infectious rate of 54.17% belonged to Nematoda. Four species of Cestoda class accounted for 41.67%, namely Hymenolepis diminuta (20.84%), Hymenolepis sp (9.38%). Raillietina demerariensis (6.25%) and Raillietina celebensis (5.21%). Echinostoma aegyptica which belonged to Trematoda class was found in infected rats with high infection rate 12.50%. Remarkably, there were Echinostoma aegyptica and Hymenolepis diminuta which could be potentially transmissible to human.

Reproductive organs of female pigs were collected from slaughterhouse in Can Tho city to determine the type of various fertility disturbances. A total of 328 reproductive organs of female pigs were examined. The following findings were recorded: reproductive abnormalities 11%, maldeveloped ovaries 6.11%, obstruction of oviduct and uterine disorder 1.83%. In abnormal ovaries, the result also showed that incidence of maldeveloped single ovary was 53.57% higher than maldeveloped multiple ovaries (17.86%), congenital anomalies of single and multiple ovary (3.57% and 7.14%), single ovarian cysts (7.14%), multiple ovarian cyst (3.53%).

To evaluate the genetic diversity and the antibacterial activity of Allium tuberosum Roxb. et Spreng, at first, the 15 plants in different places in the Mekong Delta were collected to analyze genetic diversity by using RAPD (Random Amplified Polymorphic DNA) markers, then their leaves that were planted in the same soil conditions were taken for extracting by methanol and to test antibacterial activity expressed as minimum inhibitory concentration (MIC) against eight tested bacterial strains: Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Salmonella spp., Aeromonas hydrophila, Edwardsiella ictaluri and Edwardsiella tarda by agar dilution method. Results showed that: Allium tuberosum Roxb. et Spreng was divided into 3 groups with the genetic distance from1.000 to 6.325. Their leave?s extracts had good antibacterial activity against tested bacterial strains (512 àg/ml ? MIC ? 4096 àg/ml).  They had best effect on Staphylococcus aureus (group 1b and group 2 with MIC=512 àg/ml), followed by Escherichia coli (group 3 with MIC= 1024 àg/ml) and Streptococcus faecalis (group 1a with MIC= 1024 àg/ml).

Among 1,652 dogs examined at the Hospital Animal in Cantho University and veterinary clinics in Cantho City, 122 cases recognized that have clinically pathologic changes on urinary system. X-ray test and urine test results, determined urinary system diseases accounted for 7.38%. Of those with chronic kidney disease appears with the highest percentage 31.97%, followed by 28.69% of acute renal failure, inflammatory disease 22.95% of bladder infections, bladder and urethra 16.39%. Diseases of the urinary system of the other dogs had statistically significant difference in age, breed with p

A total of 438 backyard chickens collected randomly from 3 districts (Mo Cay Bac, Giong Trom and Chau Thanh in Ben Tre province) were performed necropsy. The results showed that the backyard chickens in surveyed areas were highly infected helminths (96.58%). The helminthic infection rate in chickens decreased  100, 95.89, 93.43% respectively on the corresponding age group of 30-60, 61-120, >120 days old. Chickens were infected 16 species, including class Nematoda: Tetrameres mohtedai, Heterakis galinarum, H. beramboria, Ascadia galli, Oxyspirura mansonui; class Cestoda: Railietina echinoborida, R. tetragona, R. penetrans, R. georgiensis, and Cotuginia digonopora; class Trematoda: Philopthalmus gralli, Prosthogonimus cuneatus, Echinostoma revolutum, E. beleocephalus, Notocotylus agyptiacus, Catatropis verucosa. The high infection rate and infection intensity in H. gallinarum, Ascaridia galli, R. tetragona, R. echinobothrida were 65.16%, 49.54%, 30.59% and 19.86% respectively. The multiple infection rate of 1-3, 4-6 and > 6 species per chicken was 48.46%, 35.22%, 16.31% respectively. Mebendazole at the dosage of 30 mg/kg bodyweight in 7 consecutive days has been shown to be 100% highly effective in deworming Cestoda and Nematoda while Albendazole at the same dosage has been shown to be highly effective in deworming Cestoda, but it showed less effective in Nematoda treatment.

This study was conducted to show the effect of dietary fatty acid ?-6/ ?-3 ratios on egg production, egg yolk fatty acids and cholesterol on 480 Hisex Brown laying hens of 38 weeks of age. Birds were allocated according to a completely randomized design into 6 treatments consisting of a control and 5 ratios of fatty acid ?-6/ ?-3 (2, 3, 4, 5 and 6). The first was a control given 0% oil; the second treatment received 2.5% salmon fish oil (SFO) + 0.5 % soybean oil (SO), the third given 2% SFO+1%SO; the fourth given 1.5% SFO+1.5% SO; the fifth given 1% SFO+2% SO and the last given 0.5% SFO+2.5% SO. Dietary treatments did not affect on egg production, feed intake but increased egg weight and improved feed efficiency as compared to control (P

Diabetes in dogs is one of three important internal medicine diseases. To determine diabetes in dog, we were carried out a cross-sectional survey of 3,300 dogs at some veterinary clinics in Dong Thap province and Vinh Long province. Through history, clinical diagnosis and blood sugar testing of capillary were realized after 8 hours of feeding by One Touch Basic test paper based on glucose oxydase reaction after 5 seconds. The result was read by One Touch Basic Plus glucose meter of America. Diagnosing diabetes in dogs was relied on the standard of WSAVA, 2010 (World Small Animal Verterinary Association, 2010). The study results showed that the infectious rate of diabetes in dogs was 3.76 %. In which preclinical diabetes were 54.03 % and 45.97% were clinical diabetes. The popular clinical manifestations were polydipsia, polyphagia, polyuria, weight loss and obesity. Diabetes in dog depended on gender, breed and age. This disease appeared on every age. The infectious rate of the disease increased in older dog which was 11,4% in dog over 10 years old.

Investigation the gross lesions of ducks slaughtered at poultry slaughter-houses in Cao Lanh city to determine the proportion of lesions and kind of lesions in slaughtered ducks. Through the survey of 500 ducks in poultry slaughter-house, the results were recorded: The proportion of lesions was 38.6%. In particular, lesions occurred in an organ accounted for 46.1%, lesions in two organs accounted for 39.9%, lesions in three organs accounted for 11.4% and lesions in four organs were 2.6%. The proportion of lesions in digestive system and respiratory system was highest (33.6% and 18.4%, respectively). The proportion of lesions occurred in circulatory system and urinary and genital systems were lower (7.4% and 2.6%, respectively). For lesions in the digestive system, the proportion of lesions in liver was highest, accounting for 55.3%, followed by the intestinal lesions accounted for 23.9%; the proportion of lesions in spleen was 17%, the pancreatic lesions was lowest with 3.8%. Hemorrhagic lesions occurred in most parts of the digestive system. The proportion of hemorrhage in liver, intestine, spleen and pancreas was 29.2%, 15.5%, 5.3% and 3.8%, respectively.

This study was conducted from January 2011 to September 2011 to determine bacteria contamination rate by time and to evaluate the pig carcass quality. Total of 249 pig carcasses and slaughterhouses? environments at semi-industrial slaughterhouse in Can Tho city and An Binh manual slaughterhouse at Cao Lanh city, Dong Thap province were collected (126 carcass and 123 environmental swab samples). The ratio of contamination of total aerobic bacteria, Coliforms, Escherichia coli, Staphylococcus aureus and Salmonella from carcasses and environments at 2 those slaughterhouses increased by time of slaughtered. The environmental bacteria contamination rate of manual slaughterhouse were higher than that from semi-industrial slaughterhouse. The pig carcasses contaminated with total aerobic bacteria, Coliforms, Escherichia coli, Staphylococcus aureus and Salmonella at manual slaughterhouse were 6.14, 1.13, 1.38, 1.46 and 2.50 times, respectively higher than that from semi-industrial slaughterhouse. Pig carcasses slaughtered at semi-industrial slaughterhouse were got Vietnamese Standard (TCVN 7046:2009) in 2.12 times higher than that at manual slaughterhouse. Methods of slaughter affected to pig carcasses quality.

To determine the effect of vitamin E supplementation at various concentration (0, 125 and 250 mg/kg of diet) on egg performance and egg quality of Isa Brown laying hens, a total of 90 layers at 53 weeks of age were randomly assigned into 3 treatments, 10 replicates of 3 hens each. The hens received either a basal diet (control) or basal diet supplemented with vitamin E at 125 (E125) and 250 mg/kg of diet (E250). The experiment was done in 8 weeks. The results showed that the hens fed diets supplemented with vitamin E increased laying rate (90.3-92.9%) and egg production (50.56-52 eggs) as compared to the control (89.5% and 50.12 eggs), however, there was no significantly different among treatments (p>0.05). Feed consumption of hens was significantly highest on the control diet and the lowest on E125 from 44-50 weeks of age (p

Research of fish sausage processingfrom by-product of frozen Tra fish fillet production with materials rich in vitamin A, C and dill fiber to create high and balanced nutritional product were carried out. In this study, effects of dill treatment methods (raw or dried) and the ratio of dill addition, temperature and cooking time on texture characteristics, sensory and microbiological safety were the main investigations. The results showed that the sausage products made from Tra fish meat had high sensory value and good elasticity due to the combination of materials with 4% raw dill. The cooking process by steaming at temperature of 70 ± 2°C, 80 ± 2°C and 90 ± 2°C respectively with core temperature of 67.50 ± 0.40oC, 77.20 ± 0.84oC and 88.16 ± 0.32oC. In addition, steaming process at temperature of 80 ± 2°C for 90 minutes helped sausage achieve the highest texture characteristics and microbiological safety during 8 weeks at 2 ữ 4°C storage temperature.

Refreshment drink is traditionally called for cooked juice from natural herbs containing pharmaceutics, being extracted from different plants which are useful for cleanse the body. “Thuoc doi” (or called “Bo mam”) (Pouzolzia zeylanica L. Benn) is a typical type is known. The study was carried out to optimize the extraction of compounds with high biological activity (anthocyanins, tannins, total polyphenols and total soluble solid content) from medicinal plants. The process was investigated in the temperatures ranging of 70 to 90oC during 10 to 30 minutes and controlled pH (3 to 6). The results showed that the good conditions for extracting bioactives from “thuoc doi” plant is 90oC and 20 minutes ofboiling. The pH of extraction about 4 in combination with the stirring process recovered the highest content of bioactive compounds from “thuoc doi” plant.

In this research, a set of experiments was carried out for identifying the optimum conditions of independent variables affecting polyphenol content extraction efficiency and antioxidant activity of soybean seeds (Glycine max L.). They included the use of di?erent organic solvents (methanol, ethanol and acetone); concentrations of solvent (40, 50, 60, 70, 80, and 90 v/v %); the soybean?to?solvent ratio (1:4, 1:6, 1:8 and 1:10) and the number extraction cycles (2, 3 and 4); the extraction time (2, 3 and 4 hours) and the temperature (30, 40, 50 and 60oC). The extraction abilities of polyphenols manifested in forms of total polyphenol and total flavonoid contents (TPC and TFC) as well as the antioxidant activity by 1,1?diphenyl?2?picrylhydrazyl radical scavenging (DPPH) were used as assessment indicators. Generally, high extraction yield was obtained using aqueous acetone 70% as solvent; the most suitable soybean?to?solvent ratio was 1:6 for 3 cycles of extraction. The extraction yield could further increase using 3 hours for each cycle of extraction at the temperature of 40°C.

The study was conducted to determine the basic properties of polyphenol oxidase (PPO) in the white sweet potato (Ipomoea batatas L.). The result showed that PPO reached the highest activity in 30°C and pH 8.0. Initial PPO activity was 256.92 U/g dry material. The Km constant and Vmax value were 27.4 mM and 7.55´10-3 OD/s on ??the substrate catechol, respectively. It is clear that sweet potato PPO belongs to the group of heat-stable enzyme. PPO activity of white sweet potato was maintained at 4°C and lost 80% of its activity at 80°C. Enzymatic inhibitor studies indicated that sodium bisulphite was the most potent inhibitor for white sweet potato PPO, followed by ascorbic acid, citric acid and sodium chloride.

A process was explored for continuous enzymatic liquefaction of corn starch and subsequently saccharification to glucose. The process appeared to be quite efficient for conversion of starch to glucose and should be adaptable to corn milk processes. The effect on substrate saccharification of variables such as level of glucoamylase (0.05-0.15%), hydrolysis temperatures (60ữ70oC) and time (30 to 240 min) was studied. The degree of saccharification was assessed by determining the rate and extent of soluble solid content and glucose formed after glucoamylase treatment. Analyzed results using response surface models showed optimal conditions for hydrolyzation of corn starch by glucoamylase (enzyme concentration of 0.12% at temperature of 66.76oC during 237 to 240 minute) gave product with the highest reducing sugar content (13.61 ±  0.143%).

The aim of this study was to evaluate the effects of drying condition and extraction solvent on the antioxidant activity of corn silk. The results showed that corn silk samples dried under sun had higher antioxidant capacity than one dried at 50 oC. The corn silk extracted by ethanol/water solvent (50%,v/v) gave the best effectiveness. The highest total polyphenol and flavonoid contents of corn silk dried at normal temperature were 9.54 mg GAE/ g and 3.18 mg QE/g, respectively. The IC50 value was used to evaluate free radical scavenging ability by DPPH assay. The sample of corn silk extract was dried under sun and the sample extracted by ethanol/water (50%,v/v) solvent had IC50 value equivalently to one extracted by water solvent (0.81 mg/ml). The IC50 value of these extracts was also lower than extracts using methanol/water (80%,v/v) solvent. The results of study can be used as a basis for further research in other antioxidant activities of corn silk with the purpose of comparision with other rich antioxidant materials in nature.

The study was conducted to investigate the effects of NaOH concentration (8 to 14%) of neutralization on cocoa butter quality, refining loss and refining factor. The effects of deodorization time (15 to 40 minutes) and bleaching materials (active carbon and Fuller?s earth with the ratios ranging from 0.2 to 1 and 4 to 6%, respectively) were also investigated. Once through the refining steps, cocoa butter has been stored for about 65 days. The quality of cocoa butter was analyzed during storage. The results showed that the free fatty acid and unsaponifiable matter contents were reduced from 1.5 and 0.46% to 0.04 and 0.18%, respectively. Refining losses of cocoa butter varied from 7 to 13% during neutralization and an average of 15% in the bleaching stage. Storage of raw, neutralized and bleached cocoa butter for 65 days at ambient temperature showed a slight rise in color and free fatty acid content with neutralized and bleached cocoa butter compared with unrefined cocoa butter.

In Mekong Delta, agricultural land for growing cereals and roots has been expanded due to their high values and fertilizering the land. Specially, mung beans, water chestnuts and sweetpotatoes are food crops containing high content of starch. Although these crops are produced annually with high production, they still have not been used much in food processing. Mung beans, water chestnuts and sweetpotato roots have starch granules with different properties which is suitable for a certain food product. Therefore, the aim of this study was to investigate and correlate compositions and properties of flour and starch. Mung beans, water chestnuts and sweetpotato roots were used to examine the compositions (protein, sugar and starch contents), flour properties (viscosity and gel consistency), starch properties (amylose content, viscosity and gel consistency) and starch film quality. Statistical results were found that there were significantly different (p < 0.001) between the compositions and the properties, strong correlation coefficients (p < 0.001) between them. Starch films processed from sweetpotato starch had good sensory values (colour, ordour and texture). This knowledge is helpful for food technologists to select suitable food crops to meet the needs and new food product development.

The study was conducted to evaluate the effect of pretreatment with food additives on the quality of postharvest lotus sprout, and preservation method to prevent the browning reaction and softness of the material. The results of the study showed that fresh lotus sprout was pretreated in a solution of 0.75% ascorbic acid, 0.75% NaCl 0.75% and 0.5% CaCl2  for 30 minutes (ratio of lotus sprout and soaking solution is 1: 2) to maintain their lighness (L* value) and texture characteristic. After pretreatment, the quality of lotus sprout was still good after 14 days in cold storage with ice or cooler when it was packaged in PA film with 80% vacuum. For the lotus sprouts soaked in a solution of 1% citric acid, their freshness was maintained up to 30 days.

Starch is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. From the past decades, there has been a shift in starch hydrolysis from the use of acid to the use of enzymes in the production of maltodextrin, modified starches, glucose and fructose syrups. Starch-converting enzymes are also used in other industrial applications in which amylases are one of the main enzymes used in industry. Such enzymes hydrolyze the starch into small molecules composed of glucose units. This review illustrates an effect of temperatures (70á90oC), times (10á60 minute) and concentrations of the a-amylase (0.05á0.25%) to starch hydrolysis from Red rice. The optimum hydrolysis conditions were chosen (temperature of 90oC during 41.44 minute and concentration of ?-amylase 0.18%) to produce liquefied starch with high reducing sugar content, with relatively low viscosity, facilitating for subsequent Red rice processing.

The aim of the study was to assess the effects of raw material treatment methods on the concentration and stability of the anthocyanin extracts from purple cabbage. The ethanol solution (50%, v/v) added 1% HCl was used as solvent for extraction. Some treatment ways such as: drying, freezing, drying and freezing were applied to raw materials. In order to obtain the extract with the highest concentration of anthocyanins and the most stable one under variable conditions, purple cabbages were dried before extraction. The optimum drying temperature and moisture content of the material for drying process are 40oC and 15% respectively. Stability of anthocyanin extracts was significantly affected by heating at 95oC for 15 minutes (5.22?7.08% degradation) and exposure to light (2.50 ? 4.56% degradation after 24 hours) in comparison with dark condition.

A study was taken up to evaluate the role of some fermentation parameters on pectin methylesterase (PME) production. The Response surface methodology (RSM) based on four-variable central composite design (CCD) was used for modelling the correlation of the PME fermentation conditions such as inducer concentration-by mixture 1:1 of Aspergillus niger which were isolated from the peels of Citrus sinensis L. (So2) and Citrus maxima (R1), initial pH, incubation temperature and moisture content of medium. In this experiment, the dried apple pomace and fresh pomelo peels were used as substrate for PME production in the ratio 1:1 combined with the addition of 0.1% urea combined with 0.5% MgCl2 and 0.15% CaCl2 into fermentation media. The result showed that, the highest PME activity  (65.6 ± 3.14 U/g) obtained after 96 hours incubation at a temperature of 35.5°C, pH 4.0 (adjusted by citrate buffer), moisture content adjusted to 57.4% and 16.5% v/w of inducer concentration (105 cfu/mL). The research results indicated that RSM could be applied to found the optimum conditions of the process parameters in order to enhance the maximum pectin methylesterase production.

Traditionally, vinegar production is performed using parts of too ripe fruits or by-product of fruit processing. Vinegar could be produced using sugar and starch, which are substrates for ethanol fermentation then acetic acid fermentation. Bacterium used for  ermentation of vinegar (acetic acid bacterium) is Acetobacter which transforms ethanol (C2H5OH) into acetic acid (CH3COOH) by oxidation. In this study, vinegar was produced using bananas by controlling main factors affecting the acetic acid production, including alcohol concentration (5 to 9% v/v), sugar concentration (0 to 75 g/L) and bacteria cell population (104 to 106 cells A. aceti/mL). The Response Surface Methodology was adopted to optimize the process parameters including alcohol content, sugar content, and A. aceti population for the vinegar fermentation. The correlation between the experimental data and the predicted model was quite good (R2=0.97). For banana vinegar, the maximum acidity was obtained (4%) at 5% of alcohol level, sugar content of 20.62 g/L and A. aceti cell concentration of 105 cell per mL for 6 weeks at 37-38oC.

The main objective of this study is to identify effectively the postharvest handling conditions for quality and storage of langsat (Lansium domesticum Corr.) fruits.  Experiments were done using a completely randomized two factor design (CRD) to examine the effects of various postharvest dipping treatments and different types of packaging material. The postharvest treatments consisted of a control (no dipping) and four dipping solutions. These treatments were: (1) tap water for 5 minutes, (2) CaCl2 (0,5%) for 5 minutes, (3) NaCl (1%) for 5 minutes and (4) heat treatment in water at 50°C for 2 minutes. The dipping treatments were also combined with tests of three different packaging materials for storage. The packaging materials for storage consisted of: (1) controls (no packaging), (2) a poly-vinyl chloride (PVC) packaging wrap and (3) polyethylene (PE) packaging (10 holes with d=1 mm). All fruits were stored at 12oC after testing. Three replicates of each experiment were done, and two clusters of fruit were used for each experiment.  Overall, in terms of storage packaging material, the results showed that the quality of the langsat clusters stored in PVC wrap at 12oC was maintained for 10 days. Also, dipping the clusters in a heat treatment of tap water at 50°C for 2 minutes or using solutions of CaCl2 (0,5%) or NaCl (1%) for 5 minutes before wrapping reduced the percentage of fruit drop from the clusters and decreased frequencies of brown blemishes as compared with controls.

With the aim of using by-product from sugar industry, the study ?Isolation and selection of yeast for alcoholic fermentation from sugarcane bagasse? was carried out. Eighteen strains of yeast were isolated from different types of yeast starter powders. Ten of them named as H5, H6, H7, H9, H10, H12, H13, H15, H16, H18 were illustrated exoglucanase activity on a solid medium with sugarcane bagasse powder used as a substrate. In a process of alcohol fermentation by Durham bottles, all four strains of yeast (H6, H9, H10, H13) showed a strong capacity of alcoholic fermentation with D-glucose, D-mannose and D-galactose by creating highest CO2 columns in Durham bottles except D-xylose as a substrate for alcohol fermentation. Besides, for the evaluation of combinations, each strain of H6, H9, H10, H13 was tested with a mix of three bacteria strains BM13 (Achromobacter xylosoidans strain BL6), BM21 (Bacillus subtilis strain S2O), and BM49 (Bacillus subtilis strain FS321) in the process of alcoholic fermentation using sugarcane bagasse as a substrate, the results showed that a complex of microorganism including of the yeast strain H13 and three bacteria strains were the most suitable for making bio-alcohol with good parameters including of the highest volume of carbon dioxide (44 mL), ethanol (2.23 g/L) and reducing sugar (0.483 g/L). The most reduced rate of dry matter (DM) was 9.62% and crude fiber (CF) was27.57%.

An experiment was conducted to study the preparation of wine using locally available ?Mot bui do? rice varieties. The standard yeast strain as Saccharomyces cerevisiae was used for wine preparation after koji incubation by Aspergillus oryzae from 0.4á0.8% during 1 to 3 days in order to achieve the maximum amount of sugar, ready for fermentation. The experiment was also arranged with the blending of 5 ratios of moto: boiled rice and additional water, along with complementary sticky rice with the content from 5-20% and control sample. The study results showed that high activity ?-amylase enzyme could be obtained by koji incubation with 0.6 to 0.8% of Aspergillus oryzae in 2 days. The ratios mixing of Moto: rice: water are 1: 2: 1 and 1: 2: 2 (by weight) could be used to produce rice wine with high ethanol concentrations and low residual sugar concentrations (an average of 12.5% v/v and 2.3%, respectively). Additional sticky rice in rice wine production potentially increase the sensory value of the product, especially smell and taste. Chemical analysis showed that the methanol concentration (48-65 mg/l) in wine was much lower than the National Technical Regulations for alcohol products (QCVN 6-3: 2010/BYT).

Ginger root powder is commonly used as a spice and flavoring agent in Vietnamese dishes. This study was carried out to investigate the effects of (i) drying temperature (50ữ70oC), (ii) grinding time (20 ữ 80 seconds) and (iii) packaging materials (PE, PA, PE-paper, and PA-paper) on ginger powder quality. Assessment of polyphenol content in the solutions which were prepared by dissolving ginger powder in boiling water (100°C), hot water (80°C) and continuously boiling at 100°C for 5 ữ 15 minutes) was done.

To utilize of available and cheap materials, Vietnamese meatballs in tomato sauce were studied using fresh-water prawns (Macrobrachium lanchesteri) in comparison with traditional product made from pork. The study was carried based on changing the ratio of materials as follows fresh-water prawns : lean pork : pork lard (50 : 40 : 10, 40 : 40 : 20 and 30 : 40 : 30), gelling agents such as (i) cassava starch (0-20%); (ii) gelatin (0-6%) and the different procedures of sterilization to the quality of product. The results showed that the ratio of materials was 50 : 40 : 10, the 20% of cassava starch and the 4% of gelatin, the holding time of 15 minutes at 118oC produced Vietnamese meatballs in tomato sauce with the high quality and sensory value.

Strawberry fruit has attractive aroma and a lot of highly bioactive compounds (vitamin C and anthocyanin). However, strawberry fruit is perishable and very sour. There are many food products added with artificial strawberry flavor but few with natural fruit juice products (jam and syrup) for food processing technology. To develop new food product, this study was conducted to investigate effects of strawberry fruit nectar (i), gelatin (ii), citric acid and sucrose on physical properties (moisture and hardness), nutrients (anthocyanin and vitamin C) and sensory values of strawberry fruit gel candy. The results were found that the sucrose and citric acid affected on texture of the product. Sucrose affected strongly moisture content and texture of the product. Contents of anthocyanin and vitamin C in the strawberry candy were remained highly as the ingredients added with acid citric. Strawberry fruit gel candy had high nutrient contents, good texture and flavor if it was added with 30% strawberry nectar, 10% gelatin, 30% sucrose and 0,5% citric acid.

The experiment was conducted to aims at: examine the impact of nutritive ingredients on the growth of fungi Paecilomyces javanicus; evaluate the sporulation of fungi P. javanicus; test the detrimental effect of fungicides to the growth of P. javanicus. The result showed that SDAY3 medium was suitable for the growth of P. javanicus fungi. After 14 days of inoculation, P. javanicus fungi sporulated 108 conidia x cm-2, respectively. In in vitro condition, the five tested fungicides had detrimental effect on the growth of P. javanicus at the recommended dose. Of which Hexaconazole resulted the highly adverse impact while Carbendazim shown the slightly adverse effect on the growth of two tested fungi.

Studies were conducted to determine effects of plant growth regulators and natural light condition on in vitro propagation, rooting and acclimatization of Polianthes tuberosa L. Studies were carried out in two conditions: standard (26 ± 2oC, 1,500 lux, photoperiod 16 hrs) and natural light (30 ± 5oC, 3,000 lux, photoperiod 14 hrs), in natural light condition cultured medium not added sugar. In every condition there were three experiments, including: (1) Determination of appropriate ratios of NAA to BA to obtain the highest shoot proliferation and rooting (stage 2); (2) Determination of appropriate supplemented atonik concentration to obtain the high rooting (stage 3) rate; and (3) Acclimatization of plantlets. Results of experiments showed that in standard and natural light conditions, cultured media supplemented NAA:BA at ratio 1 mg/l:4 mg/l or 1 mg/l:6 mg/l were the most appropriate media for proliferation of shoot of two varieties H1 and H2 in both standard and natural light conditions (stage 2); effects of atonik supplement into cultured media obtained highly rooting at concentrations of 5 ml/l in standard light condition and 10 ml/l in natural light condition (stage 3); after acclimatization of two Polianthes tuberosa L. varieties H1 and H2 in standard and natural light conditions, these plantlets still grew normally.

This study was conducted to determine the combined effects of plant growth regulators and light colors on in vitro growth of Dendrobium orchid. Two experiments were carried out in this study. Experiment 1 was used to identify the combined effects of NAA, PBZ with pink and red colors on the increased number of leaves and roots in growth chamber of in vitroDendrobium. Experiment 2 was set up to determine the combined effects of NAA, PBZ with pink and red colors of light on the increased number of leaves and roots in greenhouse of in vitro Dendrobium. The results of experiment 1 showed that 0.5 mg/L PBZ + 1 mg/L NAA combined with pink color stimulated in vitro leaf and root increased better than red color combined with NAA, PBZ at the same concentrations. In the results of experiment 2 showed that plantlets cultured in greenhouse provided higher chlorophyll a, b and carotenoid contents (àg/gFW) than the ones in growth chamber.

The purpose of this study was to find out the suitable concentration of plant growth regulators and activated charcoal for shoot multiplication and rooting for triploid watermelon of Tri P1 line. The experiment was arranged in a randomized complete design with 10 treatments and 5 replicates, each replicate was equal 20 plants. The results showed that MS medium supplemented only BA at 1.0 mg/L have the highest shoot regeneration in triploid watermelon Tri P1 after 3 weeks of culture. The suitable medium was MS with concentrations of 1.0 mg/L BA for number of healthy shoots, hyperhydricity may be limited. At the same time, number of leaves, shoot length well were achieved on the medium supplemented with 1.0 mg/L BA and 2.0 g/L activated carbon after 3 weeks of culture. The number of roots, root length, number of leaves, and shoot length of triploid watermelon plantlets were best recorded in medium supplemented with 0.5 mg/L IBA and 2.0 g/L activated charcoal.

Pitaya (also called dragon fruit) normally appears flower in long day and short night condition. The study was carried out at 3 villages including An Luc Long, Long Tri and Hiep Thanh of Chau Thanh district, Long An province, for stimulated flower by an artificial light. The experiments were conducted during off-season from September, 2013 to February, 2014. At Huynh Van Xinh?s (An Luc Long village) and Nguyen Hung Dung?s orchard (Long Tri village), the dragon fruit trees were successively induced by artificial light in the second crop after harvesting the first one. At Nguyen Van Trang?s orchard (Hiep Thanh village), however, the experiment was set up only one induction in February, 2014. There were at least 6 kinds of compact fluorescent lights (CFL) with 11-20 W to be used in these experiments. Traditional incandescent bulbs (60 W IB) were used as control treatment. All of light bulbs were installed from 1,000 (IB) to 1,800 (CFL) bulbs per hecta. The results revealed that the number of branches contained sprouted buds and total sprouted buds per tree (stem cluster) of CFL treatments were always higher than that of 60 W IB. In addition, using the CFL saved 40% energy comparing to the traditional IB, and also saved approximately 7 million VND/ha/cycle of flowering induction in off-season.

The study aimed at antagonistic ability isolation and investigation of actinomycetes isolates against Pyricularia oryzae, the causative fungus of rice blast disease. Two hundred and sixty actinomycetes isolates were collected from rice field in some provinces of the Mekong Delta, and 26 isolates presented antagonistic activity against P. oryzae through preliminary assessment in in vitro condition were recorded. Antagonistic efficacy evaluation of 26 selective antifungal actinomycetes isolates against rice blast fungus was laid out with five replicates. The results showed that, 3 isolates CT68, TV8 and ST9 reduced mycelia growth of rice blast fungus with radiuses of inhibition zones reaches 43.40 mm and 32.80 mm and antagonistic efficacy of 79.66% and 72.03%, respectively at 14 days after co-culture. On the other hand, chitinase activity of the most antifungal actinomycetes isolates was performed on chitin medium with five replicates. The result indicated that, 3 actinomyces isolates CT68, TV8 and ST9 had the chitinolytic activity, with the chitin lyse halo radius of 18.8 mm; 17.6 mm and 18.4 mm, respectively at 7 days after testing.

Experiment was conducted at the experimental farm, College of Agriculture and Applied Biology, Can Tho University from September to December 2012. The objectives were to determine ages of luffa seedlings (Luffa cylindrica L.) as rootstocks and shoot cutting different times of cucumber (Cucumis sativus L.) as scions grafted on luffa to increase plant growth and fruit yield. Experiment was laid out as split-plot design with three replicates, including the main plot with three treatments of long luffa rootstock ages: 14, 19, 24 days and sub-subplot with three treatments: non shoot cutting as the control, shoot cutting at fifth-leaf and shoot cutting at tenth-leaf. Grafting techniques were applied by tube grafting methods. Results indicated that cucumber scions grafting onto luffa rootstocks got high survival ratio (higher than 91,67%) and obtained early flowering, fruitset. Ages of luffa rootstocks from 14 to 24 days after sowing did not affect on growth of cucumber and obtained yield around 27.87 ? 30.30 tons/ha. Shoot cutting at fifth-leaf increased significantly the number of branchs (3.81 branchs/plant), fruit number (29.41 fruits/plant) and yield (31.73 tons/ha) in comparison with non grafting plant (2.85 branchs, 26.16 fruit/plant và 28.90 tons/ha, respectively).

Salinity tolerance of five soybean cultivars [Glycine max (L.) Merrill] Nhat 17A, MTĐ 748-1, MTĐ 176, MTĐ 760-4 and OMĐN 29 was evaluated by hydroponics with four levels of NaCl concentration (0, 1, 2 and 4 g/l). The results showed that NaCl affected the survival ability and growth of these soybean cultivars. The increase in salt concentrations caused the decrease in survival rate, as well as height, number of internode and root length of plants. MTĐ 176, OMĐN 29 and Nhat 17A had low survival rates with 25, 20 and 10%, respectively, at NaCl concentration 4 g/l after 5 weeks planted while MTĐ 760-4 could not survive at this salt level. Particularly, MTĐ 748-1 cultivar had the highest salt tolerance (survival rate of 70%). Symptoms of salt toxicity were observed at NaCl concentration of 4 g/l including plant stunting, poorly developed roots and mature leaves had interveinal chlorosis while veins remained green, burning of leaf tips and margins, followed by leaf abscission.

The experiment entitled ?Effect of calcium fertilizer dosage on growth and yield of Japanese Purple sweet potato (Ipomoea batatas Lam.) at Binh Tan District, VinhLongProvince? was carried out to determine the optimal dosage of calcium fertilizer for sweet potatoes giving higher yield and good quality tuber roots. The experiment was set up in a randomized complete block design with 5 treatments and 3 replicates, 35 m2/each replication. The inorganic-based fertilizer of 100 kg N/ha - 80 kg P2O5/ ha - 200 kg K2O/ha was suppleted 5 levels of calcium 0, 100, 200, 300 and 400 kg CaO/ha. The results showed that the number of branches/plant, number of tuber roots/plant and ratio of marketable tuber roots/plant and tuber roots yield were not affected by used calcium dosage. Stem length, number of leaves/plant and tuber root length increased as increasing calcium level up to 200 kg CaO/ha. However, applying higher than 200 kg CaO/ha stem length and tuber root length did not increase while number of leaves/plant reduced. The sugar content (22,5%) and starch content (64,3%) in tuberous roots were highest at 200 kg CaO/ha supplement.

This study was aimed to investigate morphology, viability of pollens, and to establish methods for improving fruit set and reducing immature fruit abscission occurring on ?Ha Chau? baccaurea. Five experiments were carried out on the 8-24 years old trees (male and female) from March 2010 to March 2011 in Phong Dien district, Cantho city. Results of this study showed that size of ?Ha Chau? pollens was 18.8 ± 0.3 àm; the ratio of viable pollens, corresponding with the ratio of pollens stained by Acetocarmine, was 86%. Pollen culture media supplemented with 10 ppm of H3BO3 helped increase germination ratio and improve pollen tube extension; while supplementation with NAA at 20-40 ppm brought about pollen germination ratio higher than 50% in 6-12 h after culture (HAC), and 100% in  24 HAC. After harvesting, pollen could survive for 18 and 48 hours at room temperature, and at 20-25oC respectively. Foliar application of 40 ppm GA3 at the period of 10-15 days after fruit set reduced immature fruit drop ratio to 2.5 folds less than that occured on trees of control treatment (non-sprayed).

The purple sweet potato is rich in flavor and a good contribution of human nutrition benefits. This study was undertaken to gradually select the appropriate parameters for the processing of purple sweet potato milk. The ratio of water to materials (1:1, 2:1, 3:1) was designed for the study. The ?-amylase enzyme (Termamyl SC) was then used to hydrolyze the purple sweet potato flour at temperatures ranging from 70 to 90oC during 20 to 60 minutes with the enzyme concentration used from 0.02 to 0.08%. The quality indices were observed in this study including Brix, viscosity and efficiency. Results of the study showed that the proportion of water and purple sweet potato was selected for hydrolysis preferably 2:1 (w/w). Besides, high recovery efficiency of starch hydrolysis was achieved at temperature of 80°C during 40 min with ?-amylase concentration of 0.05%. This process is good support for further processing of the purple sweet potato milk.

This study was conducted in net house (with polymer roof, net side walls) of the College of Agriculture and Applied Biology, from August 2012 to March 2013. The objectives were to identify the compatibility of rootstocks for hybrid hot chili 207 scion that had high survival rate and yield: (1)Hiem trang, (2)Hiem xanh, (3)pepper DaLat (rootstock), (4)TN587, (5)TN588, (6)TN589, (7)TN591, (8)TN592, (9)TN596, (10)TN598 and ungrafting as control treatment. The experiment had eight replicates. Results indicated that the survival rate of grafting treatments were higher than 87.12% at 12th days after grafting. All rootstocks achieved higher yields than the ungrafted control when plants grown under net house, using drip irrigation and without soilborn disease present. Hybrid hot chili 207 scion grafting onto TN598 rootstock had the highest fruit yield (5,3 tons/ha). There was not significantly different from grafted rootstock cultivars as TN 589 (5 tons/ha), TN592 (4,6 tons/ha), TN596 (4,4 tons/ha). The ungrafted control treatment had the lowest fruit yield (2,4 tons/ha). On the whole, these results showed the effectiveness of grafting to upgrading fruit yield of hybrid hot chili 207 scion. The result is the basis for further research to find out the resistant root stocks to bacterial wilt (Ralstoniasolanacearum).

Study on bacteriophages in controlling bacterial leaf blight disease on rice caused by Xanthomonas oryzae pv. oryzae (Xoo) was conducted in laboratory and nethouse, Can Tho University. There were ten bacteriophages isolated from 26 strains Xoo original from 4 provinces of Mekong Delta i.e An Giang, Can Tho, Hau Giang, Bac Lieu with 38.46% percentage of infection by phages. Evaluation on the parasitized ability of ten phages on total 26 strains of Xoo showed that one phage could infect many bacterial strains, four phages with coded 10, 12, 13, and 17 showed higher efficiency in parasiting of many Xoo strains, and bacterial strain Xoo 44 (from Thoi Lai- Can Tho) and 52 (Long My - Hau Giang) were higher sensitive with almost isolated bacteriophage strains. Phage 12 (isolated from Chau Thanh A- Hau Giang) showed higher effect in killing strain Xoo 44 compared to phages 10,13 and 17. In nethouse, all four phages with coded 10, 12, 13 and 17 showed effect in reduction of bacterial leaf blight infection by spraying phage suspension (108 pfu/ml) on leaf surface before or after pathogen inoculation. Spraying phage suspension 10 or 12 before pathogen inoculation showed better disease reduction than spraying phage after pathogen inoculation, they showed higher disease control than two others.

This study was carried out to evaluate the growth of shoot clusters of two cultivars (Polianthes tuberosa) in vitro irradiated by gamma 60Co rays at different doses to base on evaluation of mutation later. Shoot clusters were cultured on medium MS (Murashieg and Skoog) supplemented vitamins: thiamine, pyridoxine, nicotinic acid and riboflavin 1 mg/l in each agar (8 g/l), sugar 20 g/l, coconut water (100 ml/l). Samples used to irradiate were cultured on 10 cm petry dishes. Each dish cultured 10 shoot clusters. Each treatment had five replicates. Each replicate was one dish. Cultivar number 1 (code H1) was treated at doses 0 (control), 5, 10, 15, 20, 25, 30 Gy. Cultivar number2 (code H2) was treated 0 (control), 10, 20, 30, 40, 50 and 60 Gy. Irradiated samples were cultured on medium MS supplemented vitamins (B1 and B6), agar (8 g/l), sugar (30 g/l), 0.25 mg/l NAA and 1 BA mg/l. Shoot clusters were transferred once per month. Results showed that shoot clusters of two cultivars Polianthes tuberose decreased height and number of shoot when irradiation dose increased.

The research was carried out at three villages of Ke Sach district including Ba Trinh, Ke An and Trinh Phu from March 2013 to February 2014. In each place, 10 pomelo trees were chosen for investigation of the damage ratio of the citrus fruit borer. The results indicated that damage ratio are very low or no infested fruit in the rainy season (0 ? 5.08%) and reached 26.32% in the dry season. The damage ratio of the citrus fruit borer differed significantly from both the rainy and the dry season.

Experiment was conducted at the Experimental Farm, College of Agriculture and Applied Biology, Can Tho University, from May 2011 to February 2012. The purposes were to evaluate effects of using plastic mulch and Superhume supplements on the growth, yield and economic return of green asparagus. The experiment was laid out as a Randomized complete block design, 4 treatments: (1) non using plastic mulch + non Superhume supplements (control), (2) non-using plastic mulch + Superhume supplements, (3) using plastic mulch + non Superhume supplements and (4) using plastic mulch + Superhume supplements, 4 replications. Experiment results showed that plastic mulch using and Superhume supplement had the highest marketable yield (17.45 tons/ha), highter than the control treatment 8.56 tons/ha, equivalent to 105%, increased in diameter, weight and number of shoots per plant, simultaneously increased highest benefit ratio (2.57).

Butachlor is a popular acetanilide selective herbicide used in direct seeded and transplanted rice for several years, with high efficacy and good crop safety profile. However, the risk of herbicide resistance increases with the frequency of product application on the field over many years. Penoxsulam is a K3 group, triazolopyrimidine sulfonamides herbicide which can use as pre-emergence with broad spectrum bio-efficacy against several important weeds on direct seeded rice. The mixture of GF-2913 (10 g/l penoxsulam + 400 g/l butachlor + 40 g/l fenclorim) was tested across multiple rice cultivation areas in the Mekong Delta of Vietnam from 2011 to 2014. The result showed that when applied at 0 - 3 days after seeding, the GF-2913 at rate 512.5 g a.i/ha provided more than 95% control efficacy against all important weeds in direct seeded rice, with resulting weed control that was significantly better than butachlor 600EC (butachlor + fenclorim) at 600 g a.i/ha and pretilachlor 300 EC (pretilachlor + fenclorim) at 300 g a.i/ha. The mixture of GF-2913, at a dose 512.5 g/ ha, did not show significant impact on the germination of rice seed. Rice yields of the treatments which were treated with GF-2913 at a rate of 512.5 g a.i/ha, single butachlor + fenclorim at a rate of 600 g a.i/ha and pretilachlor + fenclorim at a rate of 300 g a.i/ha were higher than that of control about 33.3 %, 22.3 % and 24.4 % respectively.

Research on ?Improving 2nd and 3rd stages of Aerides sp. orchid micropropagation? was carried out to determine ratio of suitable combination between NAA:BA for shoot multiplication (2nd stage) of Aerides orchid in two types of containers (plastic bags and glass bottle); determine effects of NAA and atonik for rooting of Aerides orchid (3rd  stage) in two types of containers (plastic bags and glass bottle). Experiments were conducted in two different conditions: standard conditions (26 ± 2oC, 1,500 lux, under a 16-h photoperiod); and natural conditions (30 ± 5oC, 3,000 lux, under a 12-h photoperiod). Each condition included 2 experiments: Experiment 1. Determining effect of ratio of NAA/BA and culture container types on shoot multiplication; Experiment 2. Determining effect of different NAA and atonik concentrations on rooting of Aerides orchid. Experimental results showed that medium VW supplemented with 1 mg/L NAA and 10 mg/L BA combined with plastic bags gave the highest number of shoots in two conditions. The natural condition, atonik was more efficient than NAA on rooting, especially at concentration of 2 ml/L, cultured in plastic bags.

The growth and development of six gloxinia (Sinningia speciosa) varieties (G1, G2, G3, G5, G7 and G11) from in vitro genetic resources were observated at Tien giang province. Results showed that all of varieties could be grown and developed for pot flower production. Among them, there were two potentiality gloxinia varieties for pot flower production with many good characteristics as compared to other varieties. The G5 variety had red double flowers, short flowering time (57.3 days), 6.1 cm in flower diameter, 8.1 flower/plant, 18.9 cm in plant diameter, flower longevity 5.3 days. The G11 variety had white purple double flowers, short flowering time (62.3 days), 6.2 cm in flower diameter, 8.5 flowers/plant, 16.8 cm in plant diameter, flower longevity 5.7 days.

Modelling an intensive bananas in Long My District, Hau Giang province was conducted from 05/2012 to 06/2013 by the two different materials of planting which were the tissued culture shoots and the traditional shoots of Xiem variety (Musa sp.) and dwarf cavendish (Musa cavendishii Lamb.). The agronomic morphologies (plant height, leaf number, circumference of pseudostem) at 8th month after planting showed that these tissued culture plants surpassed comparing to the traditional material. Bunch weight of the tissued culture cavendish of South America was heavier than the micropropagated bunch of Huong cavendish 25.8 kg and 21.78 kg/bunch, respectively. Bunch weight of Xiem variety was the same. Income from the intensive cultivation of cavendish cultivar was estimated 45 million VND/ha/crop and 18 million VND/ha/crop of the first season.

Two hundred and sixteen actinomycetes isolates were obtained from rice field in some provinces of Mekong Delta were determined for their antagonistic ability against sheath blight fungus Rhizoctonia solani on rice. Primary results indicated that, 27 of 216 isolates in total showed antagonistic ability against rice sheath blight fungus in in vitro condition. From primary results, 27 selective isolates were characteried for their inhibition efficacy of rice sheath blight fungus in in vitro condition with 5 replicates. The results found that, two isolates CT105 and CT68 (isolated from the rice fields of Can Tho city) could reduce mycelia growth of sheath blight fungus with radiuses of inhibition zones reaches 43.40mm and 32.80mm and antagonistic efficacy 79.66% and 72.03%, respectively.

Studies were conducted to determine stages of micropropagation including propagation, rooting, acclimatization and growing in the field. Studies were included two parts: in the laboratory and in the field. In the laboratory, the study was to determine factors which affected on propagation, rooting. In the field, the study was to determine factors which affected on acclimatization and evaluation of growth through demonstration. Results of studies showed that polianthes tuberosa obtained high propagation coefficient and good rooting on medium added atonik. Natural light condition (120 àmol.mư-2.s-1) stimulated rooting better. In acclimatization stage, Polianthes tuberose in atonik medium were more adaptation. In demonstration, results  showed that plantlets grew very well and flowered after 5 month planting. Inflorescences obtained with high quality and low pest.

The objectives of this study were to determine the effects of ethyl methanesulfonate (EMS) levels and gamma ray on growth, yield response of two cultivars of sesame in M2 generation. The experiments were arranged in a randomized complete factorial design in including the three treatment levels of EMS (0; 0,025 and 0,05 %) complemented with gamma rays and the two of sesame varieties with four replicates. The experiments were carried out in the greenhouse of College of Agriculture and Applied Biology, Cantho Univesity. Results showed that flower numbers, capsule numbers, seed per plant and highest variation ratio were induced by 0.025% EMS and 400 Gy in M2 generation of SĐ2 cultivar.

The survey of farmer practice for cultivation sweet potatoes was realized to understand cultivation technique and determine the status of potassium and calcium nutrition (both exchange in soil, total in tuberous root) for sweet potato production at Binh Tan district, Vinh Long province, from November 2011 to June 2012. Results of the survey of 60 households cultivating sweet potatoes showed that most of the households planted mainly Japanese Purple sweet potato variety (approximated 93.3%) and the variety was propagated in the local households. The major pests on the crop were Cylas spp. and wilt stem to be monitorated. The farmers were regularly applied many pesticides to control these pests every 7 days and total 18 times per season. The fertilizer rate for sweet potato production was around 7 to 8 times per season. The average cost of planting were approximately estimated 87 million VND/ha. With the average yield of 28.27 ton/ha, the net return was 158 million VND/ha. However, it depends on price in harvested time. The survey from 20 households cultivating sweet potato showed that the average exchangeable potassium in soil was very less around 0.241 meq/100 g of soil and calcium was rather high around 5.267 meq/100 g of soil. Meanwhile the average content of potassium and calcium in storage root were 0.967 and 0.080% on dry basis, respectively.

This study was implemented in Lai Vung district, Dong Thap province from June 2010 to January 2011 to investigate the relationship between the two factors, i.e. plant ages and yield levels, and the two phenomenon, viz. crystallization and dry juice sac (DJC),  occurring on ?Hong? mandarin. Two factor experiment was arranged in randomized complete design with 9 treatments, and three replicates each of which equalled to one tree. The first factor was plant ages including 4-6, 7-10, and >10 year old trees. The second one was levels of yield, i.e. low (40-60 kg/tree), average (60-80 kg/tree), and high (80-100 kg/tree). Results showed that N content in leaf correlated negatively (r=-0.49**) with DJC fruit ratio, whereas P content in leaf correlated positively (r=0,65**) with the same ratio. Plant age correlated negatively with ratio of DJC fruit (r=-0,69**), i.e. trees at the age of 4-6 had the highest ratio (35.61%) while trees older than 10 years had the lowest ratio. Both plant ages and yield levels correlated negatively with the ratio of crystallization fruit (r =-0.63* and r=-0.48*, respectively) in which high yield trees had the lowest ratio (3.49%) of crystallization fruit while the low yield ones showed the highest ratio (5.92%).

This study was aimed to investigate growth and yield of ?Ta Xanh? coconut and the other intercropped plants grown in freshened area of Tran Van Thoi district, Ca Mau province from Oct. 2009 to Oct. 2010. Three demonstration models providing stable yield of ?Ta Xanh coconut?, at the age of 10-15 year old, were investigated. The three models were included coconut-banana-lime, and coconut-banana-cocoa intercropping model and a coconut monoculture model. The area of each model was from 0.5?0.5 ha (50?80 coconut trees/model). Soil samples were collected twice in rainy and dry seasons. Water samples were collected from irrigation ditch and channel every three months to measure pH and EC. Results reflected that EC of water in irrigation ditch and channel was not higher than 1.5?, and pH was from 5.9?6.6. Dry season prolonging for more than 5 months was the main factor affecting growth and yield of coconut and the other intercropped plants. Coconut yield (29.7-30.3 nut/tree/year) was quite low due to low number of flower bunch/tree/year, female flower/bunch. Banana trees started to flower and were ready for harvesting after one year since planting with the number of hands/bunch from 4.93-5.67, and 10-14 fruits/hand.

Through the field surveys in the three provinces of Tien Giang, Tra Vinh, Ben Tre and district 12, Ho Chi Minh city during the period 2008 - 2010, 15 insects pests and mites on jasmine plants were recorded, they were Contarinia sp. (Diptera:Cecidomyidae), Hendecasis duplifascialis Hampson (Lepidoptera:Pyralidae) and Palpita sp. (Lepidoptera:Crambidae), Adoxophyes privatana Walker, Archips micaceana Walker (Lepidoptera: Tortricidae), Nausinoe geometralis Guenée (Lepidoptera:Pyralidae), Lawana conspersa (Walker) (Homoptera: Flatidae), Thrips orientalis Bagnall, Thrips hawaiiensis Morgan (Thysanoptera:Thripidae), Corythauma ayyari (Drake) (Hemiptera:Tingidae, Pinnaspis sp. (Homoptera:Diaspidae), Coccus sp. (Homoptera:Coccidae), Dialeurodes sp. (Homoptera: Aleyrodidae) and two spider mites Tetranychus cinnbarinus Boisd and Tetranychus urticae Koch (Acari:Tetranychidae). Among these 15 species of insects and mites discovered on jasmine, Contarinia sp., Hendecasis duplifascialis, Palpita sp. and Thrips hawaiensis Morgan were the four most important. Through the research, the biology of Hendecasis duplifascialis, Palpita sp., Nausinoe geometralis and Corythauma ayyari was also studied.

Selecting varieties tolerant to acid sulfate soil (ASS) using hydroponic system and marker-assisted selection (MAS) is effective and accurate. Two hundred rice varieties were evaluated for ASS tolerance in Yosida media with addition of 100 and 200 ppm Fe2+. Six SSR markers RM205, RM235, RM252, RM261, RM10920 và RM21772 were used to identify the ASS tolerant genotypes. The PCR patterns indicated that RM252 was associated with ASS tolerant trait. In addition, the ASS- toleranted varieties were tested for yield and yield components on the acid sulfate soil field in Winter-Spring 2012-2013 and Summer-Autumn 2013. Results showed that four rice varieties: MTL480, MTL840, MTL844 and OM6677 identified as good acid sulfate soil tolerant candidates.

The citrus fruit borer (Citripestis sagittiferella) is a newly emerging insect pest in the Mekong Delta. This survey was carried out to take part in building the Integrated control of citrus fruit borer. The research was carried from March to May 2013 in Ke Sach district, Soc Trang province. There are 90 pomelo- farmers whose orchard lager than 2,000 square meters were interviewed for their cultural practices and knowledge concerning citrus fruit borer with pre-composed questionnaires. The results showed that tree density range from 500 to 1,000 trees/ha. About 63% of the orchards of pomelo were mixed cropping. Fertilizer was applied 3-6 times per year. The diseased or insect-infested branches were cut off 1.01 time per year and to use mud from ponds as manure about 1 time per year. The majority of pomelo orchards are harvested all-year-round. The orchards of Nam Roi pomelo were infested heavy while The Da Xanh pomelo orchards were infested light. All of pomelo- farmers have seen lavars of citrus fruit borer and 50% have known their eggs. The majority (95.56%) of grower assumed that citrus fruit borer was higher serious damages in the dry season. All of interviewed farmers used insecticides to control citrus fruit borer, insecticides were applied as many as 2-4 times per month in orchards. Major insecticides used in to control citrus fruit borer were Cypermethrin (31.63% of interviewed farmers); Alpha ? cypermethrin (20%); Abamectin (13.49%); Fipronil (8.84%); garlic powder. (3.26%) and petroleum spray oils (1.86%).

This study was conducted at net house (nilon roof) for vegetable research, college of Agriculture and Applied Biology, Can Tho University, from October 2012 to March 2013 to creat grafted pepper plants in hydroponic cultures, two varieties with different fruit shapes and colors for decoration. The experiment was set up in randomized complete block design, 4 treatments including 4 cultivars: 1/ Dai Tim, 2/ Dai Trang, 3/ Trang Tam Giac, 4/ Ot Ca grafted onto Thien Ngoc rootstock. The results showed that combination of one variety grafted onto Thien Ngoc rootstock and grew hydroponic to create two grafted plants with two fruit shapes and multicolors (white, purple, orange, red changes of fruit ripening) for decoration. At 60 days after grafting, grafted plants of 4 grated combinations obtained height from 19.13-36.28 cm (very short) and canopy diameter from 8.02-16.08 cm (very small). Each grafted combination had a distinct beauty, small canopy was very suitable for decoration on the desk, white roots suspending in water can be seen. ?Ot Ca? and ?Trang Tam Giac? ornamental pepper varieties grafted onto Thien Ngoc rootstock in hydroponic cultures was very beautiful.

The aim of studies was to find out promising Bacillus species isolated in rice field soil of the Mekong Delta obtaining antagonistic capability to Fusarium monilifome causing Bakanae disease in seven provinces i.e. Tien Giang, An Giang, Dong Thap, Can Tho, Soc Trang, Hau Giang và Vinh Long. The bacteria were isolated on King?s B agar medium and identified based on colony, Gram characteristics and endospore formation. The bacteria with good antagonist were sent to Japan for further identification. Evaluating antagonistic ability based on mycelial inhibition zone (mm). Results showed that among 285 isolates, there were only 45 isolates survived at 85oC in 60 minutes belong to Bacillus, in which 6 isolates that had  showed good antagonistic but vary depend on Fusarium monilifome isolates identified as Bacillus pumilus (AGB1), Paenibacillus macerans (AGB3), Bacillus sp. (AGB4), Bacillus pumilus (AGB15), Bacillus pumilus (AGB17) and Bacillus megaterium (AGB27). Among them, Bacillus pumilus AGB15 had showed good antagonistic ability to many Fusarium moniliforme isolates at the Mekong Delta.

The research was conducted (1) to determine effects of light intensities and daylength on growth of hydroponic watercress (Nasturtium officinale B. Br); (2) determine effects of two nutrient solutions on growth and development of watercress. Research included two experiments: first experiment determined effects of 3 day lengths and combined with 3 shading conditions; second one determined effects of two kinds of nutrient solutions. Results showed that hydroponic watercress had highest yield when it received daily light integral energy at 8.36 mol/m2/d (25% full sun of whole daylength) and 16.75 mol/m2/d (50% full sun of whole daylength). Application of both nutrient solutions (Hoagland or Johnson) was sustainable for hydroponic watercress.

The research aimed at studying the capacity of chitosan in inhibition of C. gloeosporioides that causes anthranose on Hoa Loc mango. Some factors that influenced the growth of C. gloeosporioides were studied. The research could identify and isolate the Colletotrichum spp on diseased mango. The sequencing of 28S rRNA gene showed that this strain was C. gloeosporioides with 98% identity. The in vitro study showed that chitosan can inhibit C. gloeosporioides at pH 5 and 1% concentration. The study on the artificial injured mango indicated that chitosan at the above condition can inhibit the growth of C. gloeosporioides.