Vol. 10 No. 7 (2012)

Intercropping of Mondo grass (Ophiopogon japonicus Wall) into tea garden of cv. Kim Tuyen (1-3 years old) is aimed to increase the land coverage, create the favorable conditions for the tea growth and improve the farmers’ income. The impacts of mondo grass intercropping and seven fertilizing formulae on pest occurrence (diseases, insects and weeds) and plant damages were investigated. The major findings are: (i) 15 weed species were found in tea garden, (ii) Mondo grass intercropping can reduce the biomass of weeds in the tea garden, and (iii) The mondo grass is not the host plant of pests on tea. The intercropping of mondo grass led to changes in solar radiation, soil moisture and land coverage which favor pest occurrence and damage such as increasing the density and damage of Empoasca flaescens Fabr. & E. onukii Mats., Helopelthis theivora Waterh, and Colletotrichum camelliae Marasmius equinis Muler Derk. but reduce the density of Physothrips setiventris Bagn and Oligonychus coffeae Niet. on the tea plants.

Sodium chloride (NaCl) was used as an alternative herbicide to control some low shrub weeds. Mimosa pigra leaves turned brown when sprayed with NaCl. Two-days-old cotyledons of Mimosa pigra L. are capable of photosynthesis similar to mature leaflets and were used to study the morphological changes as well as photosynthesis after NaCl treatment. The results showed that NaCl at high concentrations of 10 to 60 g/l caused the loss of chlorophyll, carotenoid, leading to the loss of green color and browning of mesophyll tissue in cotyledon. Photoinhibition in Mimosa pigra L. cotyledon caused by NaCl occured only when it was exposed to strong light and reflected by a decrease in the value of Fv/Fm, QP, QN and electron transport chain of cotyledon. The rate of oxygen emission as well as carbon dioxide assimilation of cotyledon decreased as NaCl concentration increased.

The effectiveness of pesticides to control the Panicle Rice Mite (PRM) was investigated on the rice fields in Camson commune, Cam giang district, Haiduong Province during 2010 summer crop 15 days after treatment. The results showed that highest effectiveness was obtained when treated with Kinalux 25EC 2l/ha, Nissorun 5EC 0.6 l/ha, Virtako 40WG 0.1 kg/ha, followed by Angun 5WDG 0.2 kg/ha, and the least were Regent 800WP 0.07kg/ha and Comite 73EC 0.67 l/ha. In terms of rice productivity, the pesticides were ranked in the following order: Kinalux 25EC 2l/ha > Nissorun 5EC 0.6l/ha, Comite 73EC 0.67 l/ha > Regent 800WP 0.07kg/ha, Virtako 40WG 0.1 g/ha, Diazan 10H 20kg/ha, Pegasus 500SC 0,67 l/ha, Danitol 10EC 1 l/ha, and Ortus 5SC 1 l/ha.

The study was carried out in Doc Lap commune, Ky Son district, Hoa Binh province from 2010 to 2011. The aim of the study was to compare the growth rate, carcass performance and meat quality between fattening pigs of local breed (called Ban pig) and F1 crossbred pig (Mong Cai boar × Ban sow). The results showed that over the same period of age, the growth rate of both F1 (MC × B) crossbred and Ban pig were considerably low, and the average daily gain (ADG) of the crossbred (125.30 g) was remakably higher than Ban pig (65.50 g) (P<0.05). Other indicators of meat quality such as percentage of water loss, pH45, pH24 and colour of meat were within normal range of pork. It was clearly shown that using Mong Cai boar crossbred with Ban sow has improved the growth rate and carcass performance of fattening pigs. The crossing formula (Mong Cai boar × Ban sow) was recommended for popular adoption in mountainous areas of Hoa Binh province, where most of Muong communities reside.

A study was carried out on 100 broiler chickens at households of Luc Ngan district, Bac Giang provine. The chickens aged from 0 to 15 week had free diets and were raised followed Vietnamese feeding standard (TCVN2265-1994). Results showed that the local chickens had a typical beard feather.The weight of one day old chicks and 15 week old hen and cock reached 28.78 gram and 1907.05 gram and 1430.63 gram, respectively with feed conversion ratio of 3.34. Slaughter results at 15 week - old chicken showed that truncal meat proprotion, thigh meat proportion and breast meat proportion were 69.00%; 22.29% and 14.83%, respectively. The protein content in breast was higher than in thigh, while lipid content in breast was lower than in thigh.

Nghiên cứu này nhằm mục đích xác định độ tiêu hóa của cá trắm cỏ (Ctenopharyngodon idella) đối với 3 loại nguyên liệu là cám gạo, bột ngô và bột sắn. Việc xác định độ tiêu hóa của các dưỡng chất trong các nguyên liệu có nguồn gốc thực vật được thực hiện theo phương pháp gián tiếp có sử dụng chất đánh dấu Cr2O3. Cám gạo cho kết quả cao về độ tiêu hóa vật chất khô (80,3%), protein (87,9%) và chất khoáng (97,4%). Tương tự bột ngô cũng cho kết quả khá cao về độ tiêu hóa vật chất khô (88,9%), protein (84.9%) và chất khoáng (92,7%). Không có sự khác biệt có ý nghĩa thống kê khi so sánh độ tiêu hóa các dưỡng chất của cám gạo và bột ngô đối với cá trắm cỏ. Độ tiêu hóa chất khô, protein và chất khoáng của bột sắn lần lượt là 80,3%, 87,9% và 14,3% và thấp hơn so với của cám gạo và bột ngô. Kết quả bước đầu này cho thấy cá trắm cỏ tiêu hóa cám gạo và bột ngô tốt hơn bột sắn.

The experiment was carried out to evaluate the effects of salinity on fertility of selected brackish water Nile tilapia (Oreochromis niloticus) strain in 53 days. The experiment fish was arranged breeding in brackish water corresponding to three different salinity levels such as: 4 - 5‰, 8 - 10‰ and 14 - 16‰, the ratio of male: female tilapia was 1:2, each formula was repeated 3 times in 3 different tanks, stocking density was 4 individuals/m3 for each tank. Results show that the reproductive rate of females corresponding to 4 - 5‰ salinity was 26.2 ± 4.64%; 8 - 10‰: 17.86 ± 11.21% and 14 - 16‰: 6.88 ± 6.57%. The number of eggs per formula obtained after 7 times was obtained in 3 corresponding levels salinity was 5,229a ± 1,280 eggs, 2,721b ± 1,559 eggs and 923c ± 706 results. Relative fecundity 3 levels of salinity 4 - 5‰, 8 - 10‰ and 14 - 16‰, respectively, 4.3a ± 0.63 eggs/g fish/time was 3.36b ± 0.67 eggs/g female/times and 1.7c ± 1.27 eggs/g fish/time. Absolute fecundity of tilapia in salinity 4 - 5% was 829 ± 122.9 eggs/time delivery, salinity 8 - 10‰ of 678a ± 135,7 and at a salinity of 14 - 16‰ was 403b ± 154.5 eggs/female/delivery time. Natural frequency of females at 4 - 5‰ salinity 22.3 ± 2.23 days; 8 - 10% was 24.9 ± 3.7 days and 14 - 16‰ salinity was 25.7 ± 2.59 days. Experimental results showed that the breeding of tilapia at salinity level of 4 - 5‰ obtained the best reproduction, next to the level of salinity 8 - 10‰. Experiments show that the breeding of Nile tilapia at salinity level below 8 - 10‰ was high practical significance.

Three stocking densities of 6, 9, 12 heads/m2 of white leg shrimp broodstock SPF (Litopenaeus vannamei) were conducted in series of 14m2 indoor composite tanks at 28-29ºC and salinity of 28-30‰ under biosecurity control. Shrimp were fed 4 times a day with 50% blood worm and 50% fresh squid under water exchange of 100%/day. For induced breeding, eye ablation was applied to female after 30 days intensive rearing. There was no significant difference in growth, survival, rate of mating and spawning, fertilization and hatching rate among treatments (P>0,05). However, reproductive performance was significantly better in shrimp rearing at 6 and 9 heads/m2 than in those reared at 12 heads/m2 (P<0.05), reaching mature rate: 78.2-79.52%; number of spawning/female: 2.49-2.51; spawning fecundity: 152.600 - 153.200 eggs/female/spawn; average Nauplii/female: 123.9 - 127.5 x 103. Samples of broodstock shrimp, larvae and fresh food were found negative for WSSV, YHV, TSV, MBV and IHHNV.

Mục đích của nghiên cứu là phân tích thực trạng hệ thống điểm dân cư huyện Quảng Xương, tỉnh Thanh Hoá trong bối cảnh cả nước đang thực hiện chính sách “ Tam Nông”. Số liệu được thu thập từ 392 điểm dân cư. Kết quả nghiên cứu cho thấy Quảng Xương có 265249 khẩu, 65172 hộ, với tổng diện tích tự nhiên là 22780,12ha, trong đó đất khu dân cư là 6003,31ha, gồm 3350,35ha đất ở. Huyện gồm 41 xã, thị trấn với 392 điểm dân cư. Trung bình mỗi xã có 10 điểm dân cư và mỗi điểm dân cư có 676 người và 166 hộ. Việc phân loại điểm dân cư dựa trên một số tiêu chí của tiêu chuẩn Việt Nam số 4418 năm 1987, Nghị Quyết số 26/NQ-TW và các tiêu chí xây dựng nông thôn mới theo Quyết định số 491/QĐ-TTg. Kết quả phân loại 392 điểm dân cư có 71 điểm dân cư loại 1, 134 điểm dân cư loại 2, và 187 điểm dân cư loại 3. Kiến trúc cảnh quan khu dân cư còn nhiều hạn chế và có sự khác biệt giữa khu vực đô thị và khu vực nông thôn. Đến năm 2020, hệ thống dân cư phát triển theo 4 vùng của huyện. Dựa vào đặc điểm phát triển của từng vùng sẽ hình thành 5 thị trấn và một trung tâm cụm xã. Khi đó toàn huyện sẽ có 363 điểm dân cư với 140 điểm dân cư loại 1; 158 điểm dân cư loại 2; 65 điểm điểm dân cư loại 3. Để phát triển hệ thống điểm dân cư thống nhất và nâng cao chất lượng cuộc sống của người dân, chính quyền địa phương cần phải xây dựng hoàn chỉnh các loại quy hoạch và có các chính sách huy động nguồn vốn từ ngân sách Nhà nước và nhân dân.

Dak Lak province is located intheCentralHighlandwithnatural area of13,125km2andapopulationofnearly1.8millionpeopledistributed in15administrative units. Results of identifing land mapping unit by overlaytheland character maps showed theprovince's landresourcesare of great diversity, favorablefor thedevelopmentofcommercial agriculturalproduction, particularly298,365.4hectaresof redbasalt (ferralsols), accountingfor22.73 percent oftheland areaoftheprovince. Red basalt soil inDakLakprovinceis divided intofourclassification units of gentle slope and high fertility. Thissoiliswellsuited tomanyeconomic industrial perennial plants, such as coffee, rubber, cashew Basaltic soilswithslopesoflessthan150occupy 92.39 percent of the area of whichover100cmthicklayeraccountsfor84.83 percent oftheland. At present,247,190.70hectares are exploited for agricultural purpose, the rest, remains unused and non-agricultural land.

This study is aimed at exploring simple sequence repeats (SSRs) arrays and their polymorphism in Aspergillus oryzae, laying the foundations for the application of those sequences as molecular markers in investigation of genetic relationships among Aspergillus spp. isolates and in identification of a certain Aspergillus spp. strain. In silico data reveals that there is a total of 841 SSRs in the nuclear genome of Aspergillus oryzae. The density of those SSRs on 8 chromosomes ranges from 16 to 26 SSRs per Mb. The perfect SSRs sequences with 100% conserved repeats are in the majority, accounting for 44,6% of all 841 with the conservation bigger than 70%. The successful amplification of 17 SSR and iSSR loci revealed a high average number of alleles of 4,88 and a high genetic diversity with the average PIC value of 0,6 for each locus. Especially, there are specific patterns of allele number and length for each groups of the investigated moulds. This results confỉmed a high potential application of those SSR loci for detecting the presence of those moulds in human food and animal feed.

Aquaculture has experienced vast changes in the last years and significantly contributed to economic growth as a whole and the agricultural sector in particular. However, there are a number of problems caused by an unplanned developemnt of aquaculture in the southern suburb region of Hanoi. In this paper a set of management solutions for the environmental protection of aquaculture in the capital region was recommended.

Trong những năm gần đây,cung cấp tín dụng cho nông thôn từ khu vực chính thức đã tăng trưởng đáng kể. Tuy nhiên đầu tư tín dụng cho nông nghiệp còn chưa đáp ứng được nhu cầu về tín dụng cho sản xuất và chưa tương xứng với đóng góp của nông nghiệp cho sự phát triển kinh tế và xã hội trong khu vực nông thôn. Nghiên cứu này sử dụng số liệu điều tra từ hộ chăn nuôi ở Hải Dương và kết quả của nghiên cứu chỉ ra rằng tín dụng cung cấp từ khu vực chính thức vẫn chưa đáp ứng được nhu cầu về tín dụng của các hộ chăn nuôi. Tỷ lệ người phụ thuộc, diện tích đất trồng trọt, diện tích ao, số lượng lợn thịt là các yếu tố liên quan đến nhu cầu vay của hộ về tín dụng từ khu vực chính thức. Ngoài ra, tuổi, trình độ học vấn của chủ hộ, diện tích ao cá là yếu tố cơ bản ảnh hưởng đến khả năng tiếp cận tín dụng của hộ từ các ngân hàng được phản ánh bằng số tiền vay nhận được. Những hạn chế trong cung cấp tín dụng nông thôn của khu vực chính thức cũng gây trở ngại cho tiếp cận tín dụng của người chăn nuôi.

Bat Trang ceramics products are popularly consumed in the market. In the process of globalization and market integration, however, the products are also facing fierce competitions with other ceramics products, making some producers are at risks of ceasing production. Employing demand side and regional approach, this study reflects the assessments of consumers on Bat Trang ceramicsproducts in terms of quantity, quality, consumers’ characteristics, frequency and consumption purposes. The study also identified major factors affecting the consumption demands of Bat Trang ceramics products includingquantity,styles, product price, and information, in which product price is the most important factor resulting in decreasing demand of the products. The article has proposedsome solutionsto developBat Trang ceramicsproducts to boostconsumers’ demandof domestic market.

This paperreviewedresults of empirical studies of contract farmingin Vietnam and other countries. The study aimedat clarifying the conceptsof contract farming, advantagesand disadvantagesof contract farming and as well as analyzingfactors affecting contract enforcement in Vietnam. The results showedthat farm products trading under the contract between farmers and entrepreneurs in Vietnambasically has similar characteristicwith contract farming in other countries.It can be indicated that there are five models of contract farming arrangements existing in Vietnam including centralised model, nucleus estate model, multipartile model, informal model and intermediary model. Factors related to contracting context such as weakinstitutionalization of contract enforcement, market price uncertainty, low and undiversified benefits of contractand “weak market pressure”areconsidered as critical factors stronglyaffecting week enforcement ofcontract between farmers and enterprises in Vietnam.

The quality of consumed coffee bean is still low because of farming techniques, the standard unguaranty in harvesting and processing. Over 90% of the exported coffee bean outputs is based on old standards (TCVN 4193-93) which is unsuitable for Resolution 420 of the ICO. The competitive ability in quality of coffee beans in Dak Lak is much lower than with the largest producing coffee countries in the world. This study aims to evaluate the competitiveness of quality coffee beans of Dak Lak; In order to propose some mainly solutions improving the quality of coffee beans to increase their competitiveness.