Vol. 17 No. 4 (2019)

Two varieties of hybrid corn (Twin Nagas (F1) and Galaxy Corn Hybrid (F1)) were used to investigate the composition of insect pest in Vientiane, Laos. The population dynamics of H. armigera was surveyed under the influence of some ecological factors according to the method of Vietnam’s Ministry of Agriculture issued in 2014. A total of 21 species of Lepidopterous insects of 4 families were identified on maize in Vientiane, Laos in 2018-2019. Among those, the Asian corn borer (Ostrinia furnacalis) and corn earworm (Helicoverpa armigera) were more common than other species. The corn earworm densities on two corn varieties, Twin Nagas and Wasy Corn Hybrid, were similar. In four corn cropping seasons investigated, the corn earworm density in spring-summer crop was higher than thet in other croping seasons. The high density of maize (6.3 plants/m2) had higher density of corn earworm compared to the densities of 4 plants and 5 plants/m2 (2.35-2.57 ind./m2 comparing with 1.30-1.63 ind./m2) at the milking to dough stage. The corn fields with attracting plants had a lower density of corn earworm than the pure corn fields.

This study aimedto determine the prevalence of Canine distemper disease in Hanoi as an important information for disease prevention. An epidemiological study on 18244 dogs was conducted in some veterinary clinics in Hanoi from 2013 to 2018. The clinical diagnosiswas based on the specific clinical signs. Treatment and clinical outcome were followed after confirming by CDV Ag test kit.The study found that575 (3,15%) dogswereinfected with Canine distemper virus (CDV) in 14 popular dog breeds with the typiclcal gastrointestinal, respiratory and neurological symptoms. Mong Coc breed hadthe highest positive proportion (6.32%), followed by Becgiebreed (5.56%), Corgi breed (4.28%), Alaska (4.27%). The lowest positive percentage (1.62%) was observed in Rottweiler breed. The infection and successful treatment percentage significantly differred from one year to another (P <0.05). Among age groups, dogsaged 2-6 months old hadthe highest CDV positive rate (60.35%), followed by group of 6-12 months old (15.13%), under 2 months old (12,35%) and lowest in over 12 months old dogs(12.17%). The prevalence of CDV among seasonsof winter, spring and autumn were 39.13%, 35.82% and 11.83%, respectively. The infected CDV dogs also had statistically significant difference in age and season of the year (P <0.05).

In order to determine the prevalence of foot-and-mouth disease (FMD) in cattle and bufaloes and the risk of disease spread in Ha Tinh province, the monitoring samples and risk factor assessment were conduted from 4 key districts showing frequent FMD outbreaks. The results showed that the rate of buffaloes and cattle positive for 3ABC antibodies in the studied districts of Ha Tinh province was relatively high, accounting for 20.69%. Cattle without clear origin had the infection risk with FMD 13.3 times higher than those with clear origin (P = 0.00627). Cattle that were not vaccinated with FMD vaccine were 7,2 times more likely to suffer FMD than those vaccinated with FMD in accordance with regulations (P = 0,0341).

The purpose of the study was to establish the land unit map for evaluation of agricultural land potential of Mai Son district with a total surveyed area of 135,604.50 ha. Six classification criteria were determined for making land uint map including soil type, soil texture, soil depth, absolute elevation, slope, and irrigation regime. By applying GIS functions in ArcGIS, 6 corresponding thematic maps were developed. The land unit map was built by overlapping 6 thematic maps. The result showed that the study area had 114 land mapping units with 405 land parcels, of which  229 land parcels occupied the area of 200 ha or more and 87 land parcels with an area >500 ha. These were favorable conditions for selecting and developing specialized cropping area. There were 34,810 ha with favorable soil properties for the development of agricultural crops including slope ≤15°, soil depth >50 cm, from medium to heavy soil texture, and absolute elevation <1,000 m. However, the major limitation of the district in agricultural development was that the irrigated area is very low, only 1,180.77 ha (0.87% of the surveyed area.

This paper aims to introduce the automatic heat control system for indirect heating parts of the reversible multi-purpose dryer in Huong Ngai town, Thach That District, Hanoi with a drying capacity of 7 quintals/batch, helping to increase the quality of agricultural products, reducing post-harvest losses. The system was experimented with heating by burning two common waste products: pressed maize cob and rice husk firewood to utilize agricultural by-products and reduce environmental pollution. During testing, the Arduino board continuously received signals from the temperature sensor to automatically control opening and closing of the door to get fresh air from the outside for heating parts. The automatic heat control system worked sustainably and stably for the requirements of paddy drying technology at a temperature of 50°C with control temperature deviation compared to set temperature less than 5%, helping improve the product quality of the drying process. The research preliminary solved the indirect heating system control with stable heat supplied to the drying chamber through two types of agricultural waste products available.

This study develops the dynamic model that describe the behavior of a transmission system on self-propelled machine utilizing a hydrostatic transmission with a mechanical gearbox. The model is built on the basis of formulas, dynamic equations for elements from the engine to the wheel drive of the self-propelled machine and using the modular structures of Sim-Hydraulic and Sim-Mechanic software in MATLAB/Simulink environments. The model survey was carried out with input parameters determined from experiment in some typical operating conditions of self-propelled machine. The survey results are compared with experimental data to evaluate and verify the simulation model.

Both the mushroom yield and quality are affected by the type of raw materials, the use of additives, and their mixing ratio. Therefore, a proper selection of raw materials and their mixture formulation is of interest in mushroom cultivation to ensure high yield and quality. In our work, COPRAS (complex rate assessment) and MOORA (multi-objective optimization based on ratio analysis)  were applied as models to select the optimal mixture formulation and materials.  The entropy information was used  for measuring the weights of various criteria in the selection process to come up with the best setup. The model was tested with various cases and compared against available state-of-the-art experimental results from other works. The results of our model were proved to be consistent with the results of other experiments.

A study was carried out  to clarify the factors affecting the borrowing decision and the efficiency of  the preferential loan use by students at Vietnam National University of Agriculture students. The survey was conducted on 255 on-campus students and alumni of the University who had borrowed and not borrowed the preferential loan from the Vietnam Social Policy Bank during 2014-2017 period. The results showed that gender, part-time jobs and average monthly expenses were the factors that influenced the students’ borrowing decision. The T-test showed that the students who had borrowed the loan had better academic performance than the non-borrowing students with 0.17 average point. Specifically, the study showed that gender, study specialization and number of borrowing times affected students’ performance, while the effect of the average amount borrowed was not statistically significant. Based on the analysis of the results, three main solutions were proposed: 1) Implementing progressive lending amount according to learning outcomes, 2) expanding loan to wider borower range, and 3)  raising the maximum loan amount.

Due to spontaneous formation, the cluster of Craft Village Cluster (CVA) has brought both benefits and limitations to many localities. So far theoretical and practical studies on CVA are still very few, not so unified towel for identification, evaluation and proposal of development management solutions. This study aims to: Systematize and supplement some arguments about CVA; State some evidence with the CVA of Hanoi and propose some further research directions. Research information is combined between secondary and primary sources from the PRA survey in Hanoi. Methods of analyzing and evaluating mainly are in desk research methods, history research methord and expert methord. The research results include: Summarizing and supplementing concepts and 5 groups of defined criteria; Summarizing some CVA practices in the world and Vietnam; Demonstrate reasoning by discovering the existence, benefits and limitations of 33 CVAs in Hanoi, thereby proposing 5 initial research directions with Hanoi as history of formation,, operational status, development assessment, policies and solutions for management of CVAs.