A PCR protocol for simultaneous detection of Edwardsiella ictaluri and Aeromonas hydrophila infection in kidney of striped catfish (Pangasianodon hypophthalmus) was optimized. The forward primer EiFd-1 and reverse primer EiRs were used to amplify a unique sequence of 16S RNA gene of E. ictaluri with a PCR product of 407 bp (Panangala et al., 2007). The forward primer AeroFd and reverse primer AeroRs were used to amplify aerolysin gene of A. hydrophila with a PCR product of 209 bp (Panangala et al., 2007). The lower detection limit was 100 pg for E. ictaluri and 1ng for A. hydrophila extracted DNA from striped catfish kidney. The diagnostic sensitivity and specificity of the PCR was evaluated with common bacterial isolates in aquaculture including Vibrio harveyi, V. alginolyticus, V. cholerae, A. sobria; A. carviae, Pseudomonas putida, Eschericchia coli, Bacillus subtilis. The PCR appears to have good application for rapid, sensitive, specificity and low cost for simultaneous detection of E. ictaluri and A. hydrophila in infected striped catfish.

The study results "The solutions to improve livelihoods of farm households in the coastal forest in Ca Mau" shows, natural sources of capital funds have a crucial role to the selection of livelihood strategies of two groups of households. For households without land, the land is not produced by a source of labor is the decisive factor to the selection of their livelihoods. Total average income of households whose land is producing 56.44 million VND per household per year and households without land is 32.76 million VND per household per year. Besides, the spiritual life of two groups of households also improved. However, in the process of pursuing livelihood strategies, two groups of households also faced with many challenges and need solutions to improve the livelihoods of households living on the forest, contributing to the protection and development of mangrove resources.

A study of using ceacal content fluid of rabbit to evaluate gas production and feed digestibility in in vitro at Cantho University. The results showed that the ceacal content fluid could be used effectively for measuring gas production and OM digestibility in in vitro of many kinds of rabbit feeds. There was a closed relationship between gas production (mg/gOM) and OM digestibility (%) with R2= 0.80. The conclusion was that the rabbit ceacal content should be used for evaluating gas production and OM digestibility of feeds in in vitro, while the gas production technique could be used for predicting feed digestibility due to the simplicity and lower cost. Number of feeds such as para grass, wedelia sp., water spinach, natural legume leaves, cabbage wastes, broken rice, paddy rice, concentrates, brewery waste, soya waste, etc will be the potential feeds for rabbits.

Sludge sediment in shrimp ponds has caused environmental pollution which is the main concern of sustainable shrimp-farming development. The objective of this study was to determine the soil properties and some selected heavy metals of sludge sediment in shrimp pond systems. The sludge sediment soils were collected from 12 shrimp ponds in the intensive, semi- intensive and extensive shrimp systems at My Xuyen and Vinh Chau districts for soil analyses. The results showed that sludge sediment soils from the intensive and  semi- intensive which was in a range of loam clay soil, was poor in total C, total nitrogen and total phosphorus, but high concentration of available ammonium, nitrate and available phosphorus. The exchangeable sodium percentage (ESP), indicating soil sodification, was extremely high, which was 78% in the sludge sediment of intensive shrimp system and 45% in extensive shrimp system, while that value was much less (16%) in extensive shrimp system. The sodium adsorption ratio (SAR) had the same tendency which indicated the severe sodification of sludge sediment in intensive shrimp system. The contamination of Cd and Pb was lower than critical level of soil pollution. The sludge sediment soil in shrimp ponds was rich in available nutrients but high salinity and high sodium adsorption. Therefore these sediment soils can be used for agricultural production after removing salt and sodium.

The reaction of catfish fat based methyl esters with triethanolamine in the presence of sodium methoxide as a catalyst resulted in the formation of a mixture of di- and triesteramines. Quaternization of the formed tertiary amines was accomplished using dimethyl sulfate as the methylating agent to give the corresponding esterquat. This type of cationic surfactant proved to possess good emulsifying properties. Epoxidation of the C=C positions in hydrocarbon chains of unsaturated fatty acid using HCOOH/H2O2 system led to a clear improvement in the surface activity of the produced surfactant, mostly due to the change in the product water solubility. The structures of the synthesised cationic surfactants have been fully characterized based on modern spectrometry methods.

The aim of this study was to evaluate effects of successive dipterex treatments on fingerling striped catfish health (Pangasianodon hypophthalmus) through hematological parameters and growth. Fish were exposed with different concentrations of dipterex including: 0; 0.3; 0.6; 0.9 and 1.2 ppm. Each concentration of dipterex treatment was designed in triplicates and 0 ppm treatment was considered as control. The experiment was carried out within 60 days with fingerling in initial weight of 17.85±0.22 g/fish. Stocking density was 100 fish/m3. Sampling was done with 3 fish/tank at the beginning of experiment; day 1, day 4 and day 7 of exposed to dipterex. Results from this experiment indicated that numbers of erythrocytes decreased and numbers of leukocytes increased insignificantly (p>0.05) at day 4 when the fish were exposed to dipterex. However, both numbers of erythrocytes and leukocytes turned back to normal values after exposed to dipterex 7 days. Hematocrit value increased following to the increase of dipterex concentration, there was significant difference among high dipterex concentrations with control treatment (p0.05). Survival rate (SR) ranged from 88.05±2.18% ?98.11±0.00% after experiment and there was significant difference with control treatment, reducing in SR when increasing in diffterex concentrations (p

This study aims to evaluate the effects of different feeeding types on the growth and survivals of sea bass (Lates calcarifer) in order to contribbute to development of aquaculture in the coastal area of theMekongDelta. Fish fingerlings with innitial body length of 3.14cm and body wieght of 0.91g were stocked in rearing tanks of 200 L of brackish water (5ppt) at 30 fish/ tank. Five treatments with different feed types (trash fish, golden snain, pellets and their combinations) were used. Water temperature and pH were tested weekly. TAN and Nitrite as well as growth and survivals of fish were tested biweekly. Results showed that the fish have the best growth and survival rate in the treatment fed with trashfish where obtained average body weight of 6.99g, body length of 7.69cm and survival rates of 40% after 6 weeks. Fish fed with golden snails grew slower than did the trashfish but also potential for using. Pellet feed were not good for practical use at this stage. 

?Selection of high yield soybean varieties which are tolerant to pest and adapt with the natural condition of the Mekong Delta? was carried out in oder to select some high yielding soybean varieties that are tolerant with diseases, insects and high crude oil or protein content and adapt with the Mekong Delta?s conditions. On the other hand, molecular marker SSR was used as the initial discrimination of the selective varieties. Nine trials were conducted in Vinh Long, Dong Thap, An Giang, Hau Giang and Can Tho provinces. The results showed that: In the regions where had been a tradition to grow soybeans such as Dong Thap, Cho Moi (An Giang) and Vinh Long, variety MTĐ 760-4 was recommended to use for the others. This variety had high yielding of 2,05-3,0 ton/ha. Moreover, MTĐ 760-4 possesses some advantages such as short maturity, high division of branches, larger seed, the seeds with bright yellow coat. Especially, it has high protein content 41.78%, hard stem and tolerate with common diseases on soybean. In the areas having the soil condition problems such as light acidic sulfate soil, MTĐ 778-5 can be grown. Eight analyzed SSR primer pairs (Satt 153, Satt 180, Satt 316, Satt 357, Satt 371, Satt 383, Satt 455 and Satt 565) were polymorphic. The results helped to identify the differences between these varieties in the trials.

Luteolin?7,4??dimethyl ether (C17H14O6); apigenin?5?methyl ether (C16H12O5) and ??sitosterol-3-O-?-glucopyranoside (C35H60O6) were isolated from ethyl acetate extracts of Areca catechu L. root.  Structures of these compounds have been elucidated by modern spectroscopic methods: MS, 1H-NMR, 13C-NMR, HSQC, COSY and HMBC. Luteolin?7,4??dimethyl ether (C17H14O6), apigenin?5?methyl ether (C16H12O5) và ??sitosterol-3-O-?-glucopyranoside (C35H60O6) được cô lập từ cao ethyl acetate của rễ Cau.  Cấu trúc hóa học các chất này đã được xác định bằng các loại phổ MS, 1H?NMR, 13C?NMR, HSQC, COSY và HMBC.

This study was conducted on two langsat cultivars (Lansium domesticum Corr.), local and Thai, in Cai Rang district, Can Tho city from Dec. 2007 to Nov. 2008. Thirty two years old langsat trees of local cultivar, which are seedling propagated, were investigated. Selected langsat trees of Thai cultivar were those had been grown for 12 years and grafted on local cultivar rootstock. Five trees of each cultivar were studied. Growth equation of Robertson (1908) was employed to investigate development of langsat?s racemes and fruit. Results suggest that flower buds after emerging shifted to dormancy until the onset of rainy season. Duration of emerging of flower bud to blooming is about 28 days and blooming lasted within 8 days. Day time blooming possessed the highest rate of fruit set (higher than 80%. Fruit drop of 13 - 19 percent occurred two times in fruit development stage, 7 - 14 and 35 - 42 days after fruit set).  Fruits? development followed by S shape, slow in the first 30 days, faster from the day 30th to 90th, then mature and ripe at 100.2 and 109.7 days after fruit set for local and Thai cultivar, respectively. The maximum fruit growth speed varied from 71.0 days (local cultivar) to 78.5 days after fruit set (Thai cultivar.

This study investigated the effect of different stocking biomass of Kappaphycus alvarezii on the water quality, growth and production of white leg shrimp Litopenaeus vannamei. The experiment was designed with 3 treatments and each treatment was run 3 replicates: 1/Control treatment-only shrimp culture without seaweed; 2/Seaweed cultivation at 800g/m3 (NT1) and 3/Seaweed cultivation at 1600g/m3 (NT2). Juvenile white leg shrimps (4,2 g/ind.) were cultured together seaweed in 2m3 tanks. The results showed that concentrations of NH4+, NO2-, NO3-, PO43- in cultivated seaweed treatments were significantly lower than those from the control (p

Development of seedless hybrids has be 4 stages: a) choice of diploid lines, b) production of tetraploid plants, c) tetraploid line development, and d) hybrid production and testing. Seedless cultivars are produced by crossing a tetraploid (4X=44) inbred line as the female parent with a diploid (2X=22) inbred line as the male parent of the hybrid. The reciprocal cross (diploid female parent) does not produce seeds. The hybrid is a triploid (3X=33), and is female and male sterile. Generally tetraploids are developed by treating mutagens to diploid seedlings both at in vivo and in vitro conditions. The purpose of this study is to develop tetraploid watermelon lines to breed triploid watermelon.  Results showed that the treatment that in vitro colchicine treatments proved to be successful: 10% tetraploids. The treatment that was applied 0.025% colchicine for 6 days was the most effective. The ploidy level of the colchicine-treated individuals was analysed by flow cytometry. The resulting plants were then transplanted to the nethouse and to the field.

With its benefits on stability and robustness, the sliding mode controller (SMC) is applied to control nonlinear objects even under effecting of disturbances and changing of object?s  parameters. However, designing the SMC requires a mathematic model of the object which may not always obtain, in practically. As a strong nonlinear object, three-phase induction motor is difficult to control and need feedback sensors, especially for magnetic feedback sensor that is high cost and not easy to install. In order to overcome this problem, the article proposes using an artificial neural network to estimate the magnetic instead of using physical sensor, applying in sliding mode control for a three-phase induction motor. Simulation results indicate that the settling time of magnetic response is about 0.012s, and of motor speed is about 0.3s without overshoots under effecting of disturbances and changing 10% of parameter values of the induction motor.

With the aim to find a pre-harvest treatment that can improve the commercial quality and reduce the post-harvest losses of ?Soan? orange, two experiments were carried out: (1) pre-harvest treatment, including 17 treatments (control, CaCl2 (1 & 2%), sodium tetra borate (0.25 & 0.5%), 2,4-D (30 & 40 ppm), GA3 (10 & 20 ppm)) treated at 1 or 2 months before harvest and (2) effect of ethephon and chlorine with 9 treatments (control, ethephon (100 & 200 ppm), chlorine (100 & 200 ppm)) were treated at 1 or 2 weeks before harvest. The results showed that: (1) Treatment with CaCl2 1% or GA3 10 ppm as pre-harvest sprays two months before harvesting effectively reduced fresh weight loss and vitamin C content, prolonged their storage life up to four weeks in ambient condition;(2) Spraying with ethephon 200 ppm at one week before harvesting effectively degreened ?Soan? orange peel, had no effect on the fruit quality and self life compared to control. 

Study on growth and reproduction of Moina feeding by Chlorella has been achieved with 2 experiments: The first experiment was studied on the effect of Chlorella density to growth and development of Moina population at: 1.5; 2.5; 3.5 and 4.5 M cell/mL. The second one to study an effect of collecting proportion to growth and development of Moina population under three different ratios: collecting (by volume) 25%/day; 25%/2 day and collecting up to a fixed amount of 2000 ind/L day-1. Results indicated that Moina could reach as high as 16833 ± 2743 ind/mL when fed Chlorella at 4.5 M cell/mL, and maximal number of gravid females had been recorded. In the Experiment 2 when collecting was fixed at 2000 ind/L day-1 Moina displayed its best growth and maximal collecting.

Conflict over water demand, potential extreme poverty coupled with economic differentiation, and potential soil salinization in drought occurrence are three impacts caused by rice-shrimp farming in Bac Lieu coastal province, MekongDelta,Vietnam. This study uses creative approach namely Companion Modelling for quantifying those mentioned impacts. Two successive Role Playing Game sessions and a RiceShrimpMD ABM in Companion Modelling approach were co-constructed between researchers and involved local stakeholders over the period of 2006-2009. Lessons learned from the RPGs and five-year simulation results of the RiceShrimpMD ABM show that conflict over water demand for rice and shrimp crop occurs when both rice and shrimp crops coexist in the same period after September, which is a right time proposed to start rice crops. In downstream locations of the province, more conflicts occurred in the scenario where earlier salinity over 5ppt was provided in December and without any application for serving appropriate environmental conditions on rice crop. Extrem poverty and economic differentiation occurred whenever people had less concern to practice rice in rice-shrimp farming system, especially in the downstream location; rice yield reduced a bit due to the effects of salinization, compared to normal yield in the drought-free year. However, this environmental impact can be avoided as rice crops are annually practiced. Income obtained from rice crop is an essential compensation to reduce household extreme poverty. This study is confident that the companion modeling approach is an appropriate methodology for opening opportunity to all relevant stakeholders to share their knowledge of and a dialogue on water demand, enhancing better understanding of and collaboration on water management issues for sustainable development.

Twenty-two Japanese edamame varieties was characterized by 15 agro-morphology traits, 40 RAPD primers and 26 SSR primers to genetic diversity analysis. Among 35 morphometric descriptors, 22 were polymorphic (62,85%). Phenotypic diversity permitted some broad generalization and indicated the presence of important genes. A higher differentiation level was observed by using RAPD and SSR markers. RAPDs generated 219 amplification products of which 154 were polymorphic (70,32%) while SSRs produced 48 polymorphic bands out of 51 amplification products (94%). The UPGMA cluster analysis using 3 marker systems generated 4 distinct groups based on genetic dissimilarity with genetic distance from 4,47 to 10,50. It is suggested that the level of genetic diversity was sufficient for the efficent breeding program and can be used to establish genetic relationships among them with unknown or unrelated pedigrees.

A study on duck production was carried out in Dongthap province to evaluate the use of golden apple snail pests as a protein supplement to replace the soya bean meal in diets of  ducklings from 28 to 60 days of age. The experiment was a completely randomized design, with three treatments and four replicates. The treatments were 0, 45 and 90% protein of the snails replacing for protein from soya bean meal in the diets of 16% protein for the ducklings. Each plot of the experiment consisted of six ducks balanced for sex. The results of the experiment showed that daily live weight gains of the ducks supplemented different protein levels from the snails were higher than those from the soya bean meal (p

A PCR protocol to detect Aeromonas hydrophila infection in kidney of striped catfish (Pangasianodon hypophthalmus) was optimized. The forward primer AeroFd and reverse primer AeroRs were used to amplify Aerolysin gene of A. hydrophila with a PCR product of 209 bp (Panangala et al., 2007). The lower detection limit was 100 pg extracted DNA from striped catfish kidney. The diagnostic sensitivity and specificity of the PCR was evaluated with common bacterial isolates in aquaculture including Vibrio alginolyticus, V. harveyi, Edwardsiella ictaluri, Escherichia coli, Pseudomonas putida. The PCR appears to be useful for rapid and sensitive detection of A. hydrophila in infected striped catfish with much less time being used when compared to biochemical tests.

Distribution of mudskipper (Pseudapocryptes elongatus) juveniles was investigated monthly in spring tide period in the estuariesofMyThanh (Soc Trang Province) and Nha Mat (Bac Lieu Province) from April 2006toMarch 2007. Seven sampling sites (2 km intervals) were set from offshore to the interior river in each estuary. Forty fishermen collecting juvenile P. elongatus were interviewed in the study area. The juvenile density increased from the offshoresitetorivermouth,thendecreasedintheinteriorsites. Higher juvenile density was observed in mangrove forest areas than in non-mangrove sites. The smallest mean juvenile size was observed in offshore and the larger was in the interior river. The density increased from June to September. Strong correlation between the density and season, salinity and water velocity were indicated in this study. The CPUEs were 155,370 ind. net-1 per 6 months in Nha Mat and 245,644 ind. net-1 per 6 months in My Thanh estuaries.

Hydnophytum formicarum Jack. is a medicinal plant of Rubiaceae family. Young leaf explants of this plant induced calli at 75% on MS medium supplemented with either 0.5 mg/l NAA alone or in combination with 2 mg/l BA or medium supplemented with 2 mg/l NAA and 2 mg/l BA after 40 days cultured. Calli were soft, friable and green yellow color with roots. Calli were discriminated two types calli with and without roots. Both of them were cultured on MS medium with and without activated charcoal at 1g/l. Results showed that shoot organogenesis in leaf calli was not observed on MS medium with and without activated charcoal at 1 g/l. However, roots cultured with leaf calli formed small compact calli on the surface at rate of 40% after 60 days cultured. Shoot regeneration obtained 54.17% after 90 days from these calli on MS medium complemented with 1 g/l activated charcoal.

High speed semiconductor devices are the essential component of telecommunication systems, as they can handle analog and digital signals at high frequencies and high bit rates. In the frequency range of interest, silicon devices are inherently limited by material parameters such as inversion layer mobility and saturation velocity. Zinc Oxide (ZnO), are very good alternative options to replace silicon because of many advantages, for example, highly chemical resistance, potential for high power operation, and blue and ultraviolet optoelectronic behaviors [1]. The techniques have been developed to grow a Zn(O) polar ZnO and MgZnO layers on sapphire [2, 3]. In this study, the formation of the two-dimensional (2DEG) using a Zn(O) polar ZnMgO/ZnO heterostructure and its properties have been investigated. The relationship between polarity and device structure is discussed. However, the electrical properties have not been investigated in detail. So, we present a study the role of possible various confining potentials on the quantum properties of the 2DEG in a MgZnO/ZnO quantum well (QW). We proved that effect due to spontaneous and piezoelectrics polarization may significantly affect on 2DEG distribution, then on the electron transport properties in ZnO SFQWs.

From stems, leaves and roots of maize collected 78 nitrogen-fixing bateria isolates. These isolates have had the same characteristics as those described by previous authors. Using specific primers of NifH gene, 13 isolates were identified as Azospirillum lipoferum and 2 isolates were identified as Burkholderia vietnamiensis. Others have had no DNA band like the positive controls. So they did not belong to these species.

In order to support for the larviculture of the mud crab (Scylla paramamosain), comparison and evaluation of reproductive performance and larviculture efficiency based on two sources of brood female crabs caught from the sea (wild crabs) and reared in ponds (cultured crabs) were conducted in Cantho. In this study, two groups of mature female crabs were investigated: It could be distinguished wild and cultured crabs based on their outside shell color. In similar size class, wild crabs possessed larger ovaries compared to cultured crabs. Time to spawn, egg quality and larval performance were better in wild crabs. Although wild crabs were more beneficial, both crab sources were highly profitable in larviculture. Other reproductive characteristics and indexes were not significantly different.

?Selection of high yield soybean varieties which are tolerant to pest and adapt with the natural condition of the Mekong Delta? was carried out in oder to select some high yielding soybean varieties that are tolerant with diseases, insects and high crude oil or protein content and adapt with the Mekong Delta?s conditions. On the other hand, molecular marker SSR was used as the initial discrimination of the selective varieties. Nine trials were conducted in Vinh Long, Dong Thap, An Giang, Hau Giang and Can Tho provinces. The results showed that: In the regions where had been a tradition to grow soybeans such as Dong Thap, Cho Moi (An Giang) and Vinh Long, variety MTĐ 760-4 was recommended to use for the others. This variety had high yielding of 2,05-3,0 ton/ha. Moreover, MTĐ 760-4 possesses some advantages such as short maturity, high division of branches, larger seed, the seeds with bright yellow coat. Especially, it has high protein content 41.78%, hard stem and tolerate with common diseases on soybean. In the areas having the soil condition problems such as light acidic sulfate soil, MTĐ 778-5 can be grown. Eight analyzed SSR primer pairs (Satt 153, Satt 180, Satt 316, Satt 357, Satt 371, Satt 383, Satt 455 and Satt 565) were polymorphic. The results helped to identify the differences between these varieties in the trials.

Eight medical plants in MekongDelta were collected including Ceiba pentandra, Phyllanthus urinaria, Phyllanthus amarus, Eurycoma longifolia, Peperomia pellucida, Tinospora crispa, Piper sarmentosum and Tinospora cordifolia. Eight crude methanolic plant extracts from these species were screened antimalarial activity in vitro using inhibition of ?-hematin (BH) formation assay. The results show that six methanol plant extracts have ability to inhibit in vitro ?-hematin formation. The activity of P. urinaria, P. amarus and C. pentandra extracts is 2 mg/ml. T.crispa methanol extract inhibit BH formation at concentrations of 1, 0.5 and 0.25 mg/ml. P. sarmentosum methanol extract was inhibited heme converts to BH at 0.25 mg/ml. Meanwhile, P. pellucida extract showed the activity of various concentrations (2, 1, 0.5 and 0.25 mg/ml). The IC50 value of P. pellucida extract  was 0.8 mg/ml. The crude methanolic extract of P. pellucida was fractionated into diethyl ether and water. Finally, The compounds from crude water extract of P. pellucida were isolated by using high performance liquid chromatography (HPLC) method. All the crude extracts and six HPLC fractions of P. pellucida were tested the ability of antimalarial activity at in vitro and cell level. The results proved that they could inhibit BH formation inhibition at in vitro and cell level significantly.

Phu Tan district is an area with sticky rice production area of 30,000 hectares where major common variety are the normal sticky rice (CK2003) and a fragrant sticky rice NK2. To diversify aromatic glutinous rice varieties for the production of this region. Thus, this topic was initially carried out a cross (CK2003 x TP5) to select the pure lines of sticky, fragrant short, good quality. The topic was conducted from February 2008 to March 2010 three lines L1, L2 and L3 [THL01-03-03-02-02-1 (L1), THL01-03-01-02-01 -3 (L2), THL01-03-01-02-02-1 (L3)]. The experiment was conducted for comparison with control variety, CK2003 randomized complete block design, four treatments, three times replications in autumn 2009 and spring 2009-2010. The monitoring and evaluation indicators include levels of amylose, protein, fragrant checked with KOH 1.7% method, DNA electrophoresis, SDS-PAGE protein. The results showed that three lines selected of pure aromatic sticky L1, L2 and L3 with a length of DNA with aromatic molecules were 257bp, short days (# 90 days), low amylose content of = 10 %, high yield and stability across the two seasons (5.5 tons / ha - 7.3 tonnes / ha).

Experiment was performed in two different soil-profiles (Rich- vs. Poor-organic matters) and two culture systems (Improved extensive vs. Semi-intensive); intergrated culture of mud-skipper and mud-crab was applied. The results indicated that at the poor-soil profile and improved-extensive system could produce a yield of mud-crab and mud-skipper as high as the others (835±92,81 kg/ha/crop compared to 816,56±201,97 to 1005,63±50,38 kg/ha/crop). Accumulation of N, P was estimated, in which an accumulation of 7,53±3,88 up to 10,24±5,87 kg N/ha/crop in rich organic matter soil and 3,54±0,12 kg N/ha/crop in poor organic matter soil was recorded.

A socio-economic survey carried out in 2006 aimed to evaluate the possiblity of replacing mono-rice by a rotational rice-fish farming system in Co Do and Vinh Thanh district of Can Tho city. Sixty-three farmers practicing mono-rice farming and sixty-two farmers applying rotaional rice-fish farming system were independently interviewed. Total input costs of ricefarming and total net income were not significantly different (p>0,05) between farming systems 2 rice crops rotated and one fish crop (2 rice- fish), 3 rice crops rotated and one fish crop (3 rice- fish), two and three rice crops alone per year. Total input costs of the third rice crop was significantly higher than that of the fish crop (p0,05). Farmers should replace a rice crop by a fish crop during the flood period to improve farming income and stimuate the sustainability of their rice production.

Reproductive cycle and biochemical compositions of oyster Crassostrea sp. sampling from the mangrove forest in Ngoc Hien district, Ca Mau province, were studied during year 2008. The results showed that oyster Crassostrea sp spawned all year round, with two spawing peaks in April-May and September-October. Temperature and salinity were the main factors relating to the reproductive cycle of this species at studied site. The proximate compositions of oysters were not remarkable fluctuation during year cycle, in which the protein content ranged from 51-59%, followed by carbohydrates (21-31%) and lipids (6-9%). The variation of biochemical compositions had no correlation to gametogenesis and reproductive cycle of C. sp at the studied area.

This study investigated the effects of pre-harvest treatments on fruit quality during storage period and cell wall composition at harvest time. Three-year Hong mandarin trees growing at Lai Vung, Dong Thap, were used for this experiment in CRD with 2 factorial designs: 7 chemical treatments and 3 applied times. The results showed that, applying treatments three times in some cases increased fruit weight and oBrix. Spraying CaCl2, alone or in combination with H3BO3, increased fruit weight, oBrix and vitamin C content, minimized fruit weight loss during storage. Applying pre-harvest treatments  two or three times before harvest decreased total soluble sugar (TSS) of methanol and increase in pectin, hemicellulose and cellulose contents. Treatments with CaCl2 and H3BO3 alone or combined each other decreased TSS of methanol and distilled water fractions, but increased in pectin, hemicellulose and cellulose contents in fruit sacs at harvest time.