Tạp chí Khoa học Nông nghiệp Việt Nam

Nitrogen Use Efficiency of Upland Rice in Northwest Region

Nguyễn Văn Khoa, Phạm Văn Cường — Thu, 19 Oct 2017 12:27:19 +0700

The efficiency of nitrogen fertilizer in upland rice variety “Nếp nương tròn” and the control variety LC93-1 was evaluated in a nethouse pot experiment at Tay Bac University in Son La city. The pots were filled with 5 kg of upland soil. Plants of two varieties were fertilized with five levels of nitrogen: 0 mgN/pot (N0), 200 mgN/pot (N1), 400 mgN/pot (N1), 600 mgN/pot (N3), and; 800 mgN/pot (N4). The experiment was designed in randomized complete blocks with three replications, each replication consisting of 3 pots. The result showed that increased amount of nitrogen fertilizer from 0 mg/pot (N0) to 800 mg/pot (N4) increased plant height, number of panicles/hill, number of filled grains/panicle, biomass and grain yield in both varieties. Increased level of nitrogenous fertilizer led to apparent increased nitrogen concentration in stems and leaves but litle in grains. However, the amount of nitrogen absorbed by stem, leaves and grains and the total amount of nitrogen increased with the increased level of nitrogen fertilizer applied. Nitrogen use efficiency (NUE), agronomic efficiency (AE), physiological efficiency (PE) and utilization efficiency (UE) of two varieties declined with increased amount of nitrogenous fertilizer. Highest utilization efficiency (UE) was obtained at low nitrogen level.

EFFECT OF ORGANIC AND INORGANIC FERTILIZERS ON GROWTH AND FLOWER QUALITY OF POTTED BEGONIA AND PETUNIA

Nguyen Thi Ngoc, Vu Ngoc Thang, Dong Huy Giới, Li-Hua Tang, Ya-Ning Chang — Thu, 19 Oct 2017 13:56:21 +0700

The objective of this study was to evaluate the effect of organic and inorganic fertilizers on growth and quality of potted flowers. Three types of fertilizer (composite organic fertilizer (COF), composite inorganic fertilizer (CIF), and foliar spray of multi-nutrients (FSMN) were used for two flower species, Begonia (Begonia semperflorens) and Petunia (Petunia hybrid Vilm). The results showed that application of fertilizers enhanced the growth, physiology, and quality of both flower species. The growth characteristics and quality of both flower species in COF treatment were higher than those in other fertilizer treatments. Specifically, treatment of COF stimulated growth of lateral branch, number of leaves, leaf chlorophyll value and photosynthetic rate of both species. In addition, the highest flower diameters, number of flowers/plants, and flower longevity were observed in COF treatment. Days to first flowering of both species in COF treatment were also shorter than those in other treatments.

Breeding of New Maintainer Lines for Development of CMS in Hybrid Rice Breeding in Viet Nam

Bùi Viết Thư, Vũ Thị Thu Hiền, Nguyễn Thị Trâm — Thu, 19 Oct 2017 14:02:11 +0700

In three-line hybrid rice system, the development of new maintainer lines (B lines) suitable to ecological conditions with good characteristics plays an important role. In this study, we had made two combinations,BoB x IR58025B and II32B x IR58025B and applied pedigree method ofselection for short stature plant, short growth duration, high stigma exsertion, pollen abundance and good grain quality. Twenty five and 23 new B lines from BoB x IR58025B and II32B x IR58025B were selected, respectively, in F6 generation in spring season 2012. Those lines showed very good characteristics that are suitable for B lines possessing the desirable traits mentioned above. Crossing these lines with CMS line (IR59025A) showed that most of the lines produced F1 with 100% sterility. Therefore, the new maintener lines can be developed by crossing between two B lines which can be maintained for two types of cytoplasm to develop new CMS background for development of three-line hybrid rice in Viet Nam.

Development of Aromatic Thermo-sensitive Genic Male Sterile (TGMS) Lines

Nguyễn Văn Mười, Phạm Thị Ngọc Yến, Trần Văn Quang, Nguyễn Thị Trâm — Thu, 19 Oct 2017 14:07:56 +0700

The aromatic thermo-sensitive genic sterile lines were selected from segregating populations of crosses between T1S-96 and T7S used as female and pollinators BT7, Basmati 370, Hoa sua and Huongcom using pedigree method of selection. These lines were of sterile type without pollen. All of 23 TGMS lines were genotyped with tms5 while AT19 line had both tms2 and tms5 gene, 22 TGMS lines were genotyped with fgrfgr gene. Five lines (AT1, AT5, AT9, AT24 and AT27) had short growth duration and desirable phenotype. These lines showed good tillering capacity, violet stem andawn, and long grain. The leaves and endosperm of these lines possessed aromatic smell. The critical sterility inducing point (CSIP) of these line are 24^oC with high outcrossing rate.

Site-Specific Nutrient Management for NPK Fertilization in Sugarcane in Mekong Delta Alluvial Island Soil

Nguyễn Kim Quyên, Ngô Ngọc Hưng — Thu, 19 Oct 2017 14:12:17 +0700

Site-specific nutrient management (SSNM) was used to: (i) evaluate the effect of inorganic and sugarcane dregs as fertilizers on sugarcane yield and Brix and (ii) determine the NPK uptake and agronomic efficiency (AE) thereby to recommend fertilizers rate for sugarcane cultivation in the alluvial island soil. Field experiment with sugarcane of new planting crop (2011) and ratoon crop (2012) was conducted at Cu Lao Dung District of Soc Trang. The experiment was arranged in a Randomized Complete Block Design (RCBD) with four replication and two factors: (A) lacking particular macronutrient(s) (NPK, NP, NK, PK) and (B) sugarcane dregs (BBM, KBB). Results showed that potassium application at 200 kgK₂O/ha increased Brix of sugarcane. Nutrients supplied by the soil were 32.6; 46.2 and 56.1 (N, P and K respectively) as percentage of total nutrient requirement of the plant. Nitrogen was the most important factor affecting sugarcane yield. Sugarcane dregs application at 10 tons/ha increased NPK uptake by the plant. By using SSNM,331 N-155 P₂O₅-253 K₂O (kg/ha) are recommended for sugarcane grown in the alluvial island soil.

ESTIMATION OF mRNA ACCUMULATION AND PHYSIOLOGICAL RESPONSE TRAITS ASSOCIATED WITH SUBMERGENCE TOLERANT GENE SUB1A IN RICE PLANT (Oryza sativa L.)

Pham Van Cuong, Fukao Takeshi, Julia Bailey-Serres — Thu, 19 Oct 2017 14:19:06 +0700

The experiment was conducted to estimate mRNA accumulation in a submergence tolerant genotype M202 (Sub1). Nineteen-day-old seedlings of two genotypes (M202 (Sub1) and M202) were exposed to submergence. Leaves and meristems were sampled before applying submergence treatment and at 1, 3 and 7 days of submergence for estimating Sub1A and Adh1 mRNA accumulation. The results showed that the levels of mRNA increased in abundance as plants have undergone stress, especially at 3 days of submergence. The mRNA concentration also accumulated more in the meristem than in leaf tissues. The other experiment was conducted to compare the rate of recovery of photosynthesis and plant growth of the submergence-tolerant M202 (Sub1A) and the intolerant M202. Twenty three-day-old seedlings in soil-containing pots were completely submerged for up 3, 6 and 10 days (d). Photosynthetic and growth traits were measured before submergence treatment (0 day) and after 1 hour and 24 hours of recovering at 3, 6 and 10 days of submergence. When plants were prolonged under stress condition, all the photosysnthetic parameters such as photosynthetic rate, stomatal conductance, transpiration and water use efficiency decreased much more in M202 (Sub1) than those in M202. On the contrary, these parameters were able to recover in M202 (Sub1) better than in M202. Similar patterns were revealed for plant growth characters including plant height, number of leaves and tillers. The results indicated that Sub1A gene restricted photosynthesis and stem elongation and leaf area in the tolerant genotype M202 (Sub1) during submergence but increased the rate of photosynthesis and dry matter accumulation after de-submergence.

EFFECT OF NITROGEN APPLICATION LEVELS ON GROWTH OF RICE UNDER DROUGHT STRESS CONDITIONS

Tran Thi Thiem, Yamauchi Akira — Thu, 19 Oct 2017 14:23:28 +0700

The aim of this study was to investigate effects of nitrogen (N) application on root system development, photosynthetic rate and dry matter production under different drought stress conditions. The experiments were conducted in a line source sprinkler system creating a soil moisture gradient under a rain-out shelter. Three N fertilizer treatments were applied: 60, 120 and 180 kg N ha^-1 . Nitrogen fertilizer was mixed well with phosphorus and potassium fertilizer at the rate of 50 kg (P and K) ha^-1 and applied as basal dressing at 8 days after transplanting. The obtained results showed that increase of N level from 60 to 120 kg N ha^-1 increased total root length and shoot dry weight of Nipponbare under severe drought stress conditions (<17% w/w of soil moisture content (SMC)) but did not increased those traits as increased N application from 120 to 180 kg N ha^-1. However, under mild drought stress (17- 25% w/w of SMC) and well-watered (>25% w/w of SMC) conditions, total root length increased with increased N application leading to increase stomatal conductance and photosynthetic rate, and eventually increased shoot dry weight. In addition, only under well-watered conditions the relationship between the total root length and shoot dry weight was positive and notably significant at 120 and 180 kg N ha^-1 levels but not at 60 kg N ha^-1 level. The experiment suggested that the nitrogen application levels of 120 and 180 kg N ha^-1 increased the dry matter production due to the increased total root length under well-watered conditions.

Reproductive Performance and Selection Orientation for Duroc, Landrace and Yorkshire Sows at Nuclear Breeding Pigs Company Dabaco

Thu, 19 Oct 2017 14:30:11 +0700

The study was conducted to assess reproductive performance, estimate heritability and repeatability and orientate selection for number of piglets born alive and number of weaned piglets of GGP sow herd raised at the nuclear breeding pigs Company Dabaco. The data on pedigree, reproductive performance of the pure breeds Duroc, Landrace and Yorkshire that included 85, 267 and 321 for sows; 208, 649 and 919 litters, respectively, during the period from 2012 to 2015 were collected and statistically analyzed for estimation of heritability, repeatability and breeding value prediction. All three pure-bredsposs high level of reproductive performance (Duroc, Landrace and Yorkshire sows had 9.33, 10.48 and 10.85 for number of piglet born alive, 9.71; 10.35 and 10.31 for number of weaned piglets, respectively). The heritability and repeatability of these traits were low (h2 = 0.04-0.08; r = 0.05 -0.11) and showed a wide range. Applying BLUP method to predict breeding values for the two traits revealed correlation of breeding value between sows and their offspring. Variation in genetic tendency over the years suggested the necessity of selective orientation based on BLUP to improve genetical gain of two traits for GGP sow herd raised at the Company.

EFFECT OF LOW WATER TEMPERATURE ON THE PATHOGENICITY OF WHITE SPOT SYNDROME VIRUS (WSSV) IN KURUMA SHRIMP (Marsupenaeus japonicus)

Dang Thi Lua, Ikuo Hirono — Thu, 19 Oct 2017 14:35:34 +0700

White spot syndrome virus (WSSV) is a highly lethal, stress-dependent virus which causes serious economic losses for shrimp farming worldwide. Measures that boost/stimulate the shrimp immune system to control WSSV are not yet available and, therefore, environmental management to minimize stress plays a major role in disease prevention. This study was performed to investigate the effect of water temperature on WSSV infectivity, and to evaluate the effect of low temperature on pathogenicity of WSSV in kuruma shrimp, Marsupenaeus japonicus. The results showed that the earliest and highest mortality patterns, culminating with 100% mortalities at 7 d.p.c., were observed when shrimp was continuously kept at 25^oC, followed by those of shrimp was continuously kept at temperature of 20^oC. The best survival (80%) was observed when shrimp continuously kept at 15^oC. The delayed and reduced mortalities were observed when shrimp were transferred from 25^oC to 15^oC compared to shrimp held at 25^oC before and after WSSV challenge. In contrast, the increased mortalities were observed in shrimp shifted from 15^oC to 25^oC when compared to mortalities of shrimp continuously held at 15^oC. PCR and RT-PCR provided evidences confirming and supporting the mortality assay. This study shows that WSSV infection in kuruma shrimp is temperature dependent and shrimp was highly susceptible to WSSV infection at around 25^oC. Low temperature (15^oC) reduces rather than stop WSSV replication in infected shrimp. Shrimp at 15^oC may act a carrier of WSSV and could spread the disease if water temperature is increased.

Use of Microbial Formulations to Produce Bio-Organic Fertilizer from Mushroom Culture Residues and Chicken Manure

Thu, 19 Oct 2017 14:41:52 +0700

A study was conducted to identify suitable microbial formulation for producing bio-organic fertilizer from mushroom culture residues and chicken manure. Ten days after composting, the temprature in the middle of the compost mix inoculated with CPVSV3 (CT3) ranged from 51 to 56^oC, higher than those in other treatments and remained for 5 to 7 days. After 30 days, the C/N ratio was lowest in the CT3 (13.64) while the amounts of total N (1.04%), available phosphorus (187,9 mg/100g) and potassium (416,2 mg/100g) were higher than those in other treatments. The microbial formulation CPVSV3 helped restrict the growth of E. coli and Salmonella and increased the number of amonium and cellulose decomposing bacteria. The concentration of heavy metal elements (As, Cd, Pb, Hg) in the bio-organic fertilizer were much lower compared to Vietnamese standard. The actual yield of baby bok choy (Brassica rapa ssp. Chinensis) applied with micro-organic fertilizer reached 1.18 kg/m², higher than that in traditional manure application. The amounts of As, Cd, Pb, Hg as well as number of E. coli, Salmonella in baby bok choy were also lower than Vietnamese standard set by the Ministry of Health. The results suggested that the microbial formulation CPVSV3 is suitable for handling the mushroom culture residue and chicken manure mix to produce bio-organic fertilizer for safe agricultural production.

INTEGRATION OF LANDSLIDE SUSCEPTIBILITY INTO LAND USE PLANNING (LUP) IN MAI CHAU DISTRICT, HOA BINH PROVINCE, VIET NAM

Do Van Nha — Thu, 19 Oct 2017 14:45:15 +0700

Land Use Planning (LUP) plays the vital role in social economic development, especially in land use. Therefore, improving quality of LUP is of great concern in Viet Nam, especially in regions that are influenced by climate change. The objectives of the research were to answer the following questions: (1) How to integrate landslide susceptibility into LUP? and (2) What benefit from the integration do the local people get? GIS applications were used to carry out the research in Mai Chau District. The results show that 6.30% area of the district was estimated as lowly suitable or unsuitable for some land use types proposed in LUP. If the integration was conducted in 2000, some land use types would be changed to others that were more suitable in comparison with actual land use types in the areas of high landslide susceptibility.

Evaluation of Paddy Land Use in the Mekong River Delta

Nguyễn Hoàng Đan, Nguyễn Khắc Thời, Bùi Thị Ngọc Dung — Thu, 19 Oct 2017 14:50:18 +0700

The Mekong River Delta (MRD) is the main area of food production of crucial importance for ensuring national food security and agricultural product export. Based on the existing paddy land and thanks to the intensive production management and exploitation of the regional potentials and advantages, paddy production has gained fairly high growth rate during recent years. However, the use of paddy land in this region still shows shortcomings and lack of sustainability. Moreover, rice production in this area is affected by negative impacts of climate change - sea level rise. This study focused on evalution of the current situation and changes in the use of paddy land and economic efficiency of the different paddy land use types in order to clarify the current situation of the paddy land use and to discern the advantages and disadvantages in paddy production in this area, thereby to propose rational structure for paddy land use.The results showed that in the 2005 - 2010 period, the paddy rice land increased by 18.4 thousand hectares but declined by 14 thousand hectares in the 2010 - 2014 period. In 2014, at the national level, the paddy rice area in MRD accounted for 53.93% and rice output accounted for 56.13%. Summer - Autumn cultivation season had the largest rice cultivation hectarage, accounting for 54% of total rice cultivation area of the region, whereas Winter-Spring season had the highest productivity (20.5% higher than the average yield of the region). However, Autumn-Winter cultivation season had the lowest productivity and area under rice. Rice production yields in moderate to fairly high income for the rice farmers, depending on soil types.

Selection of Streptomyces spp. Isolates with Antifungal Activity against Rice Blast Fungus, Pyricularia grisea

Nguyễn Thị Phong Lan, Võ Thị Thu Ngân, Trần Phước Lộc, Trần Hà Anh — Thu, 19 Oct 2017 16:46:56 +0700

Biological control of plant diseases including fungal pathogens has been considered as viable alternative to chemical control. A total of 395 isolates of Streptomyces were evaluated as antagonist agents to Pyricularia grisea. Of these, 50 isolates of Streptomyces showed high antagonistic ability to four races of P. grisea. Six Streptomyces isolates were identified as Streptomyces cavourensis S27, Streptomyces xiamenensis S257, Streptomyces viriabilis S28, Streptomyces iakyrus S233, Streptomyces scopuliridis S136, and Streptomyces fulvissimus S30, that were highly antagonistic to P. grisea. These isolates grew well on medium at high temperature (30^oC) and fairly high salt concentration and produced high level of IAA.

Comparison of INC and P&O Algorithms in Maximum Power Point Tracking Control of Independently PV System

Nguyễn Viết Ngư, Lê Thị Minh Tâm, Trần Thị Thường, Nguyễn Xuân Trường — Thu, 19 Oct 2017 16:51:50 +0700

Solar energy is clean and free of cost and does not pollute the environment. The research of solar energy systems plays a very important role that contributes to fully exploit the natural energy resources while traditional energy sources become scare. Maximum Power Point Tracker (MPPT) control for Solar panels considered as an indispensable part of the solar power system is applied in order to improve the efficiency of solar panels. This paper described and compaired Perturb and Observer (P&O) and Incremental Conductance (INC) algorithms that were used to implement for Maximum Power Point control of Solar panels. Simulation results showed that INC algorithm had a better effect than P&O algorithm did.

Effect of Postharvest Treatment on Quality Changes of Longan Cv Huong Chi during Cold Storage

Trần Thị Định, Nguyễn Thị Quyên — Thu, 19 Oct 2017 16:55:45 +0700

Longan (Dimocarpus longan) fruit is one of the most popular fruits in Viet Nam. However, postharvest pericarp browning and rapid decay limit the postharvest life of longan fruit. In the present study, the effect of different postharvest treatments on fruit quality was investigated. The incidence of microbial disease, browning index, weight loss, polyphenol content and other nutrional quality attributes were determined at harvest and 10, 20, 30, 35 days after storage. Results suggested that pericarp browning, microbial disease, and fruit quality deterioration could be better delayed compared to the control at 35 days after storage by dipping fruits in carbendazim 0.1%, followed by oxalic acid 4 mM, finally packed in polypropylene bag with 0.008% of relative perforation area and stored at 4 ±1^oC and relative humidity of 95%.

Screening of Actinomyces ssp. for Antagonistic Activity against Rice Sheath Blight, Rhizoctonia solani Kuhn

Thu, 19 Oct 2017 17:03:58 +0700

In this study, 10 isolates of the rice sheath blight fungus (KV1, KV6, KV8, KV10-KV16) were isolated from 20 different diseased samples collected in Ha Noi, Hai Duong, Thai Binh, Ha Nam and Hung Yen provinces. They were characterized based on cultural, morphological and physiological properties. In addition, PCR-RFLP and rDNA-ITS sequence analyses were also used to identify these isolates. Inoculation of 10 isolates on four non-glutinous cultivars Xi23, Q5, Khang dan and, BC15 and 2 glutinous rice cultivars, TK90 and 87 showed that 100% infection rate was achieved and the most virulent isolate was KV13. In vitro screening of 80 Actinomycetes isolates for antagonistic capability against the KV13 showed that 10 isolates of Actinomycetes had strong antagonistic activity. Of these, the Actinomyces isolate L2.5 showed the highest antagonistic activity against the isolate KV13. This isolate can be used for further study to develop products for sheath blight control in rice.

Antifungal Ability of Nanochitosan against Colletotrichum acutatumL2 in Post Harvest Tomato Fruit

Thu, 19 Oct 2017 17:10:27 +0700

This study examined the antifungal effect of nanochitosan on Colletotrichum acutatum L2 isolated from anthracnose infected tomato both in vitro and in vivo. The results demonstrated that nanochitosan inhibited the spore germination and the growth of C. acutatum L2. Inhibitory effect of 50% and 90% mycelial diameter and dry biomass was achieved at the nanochitosan concentration of 0.75 g/l and 1.53 g/l, 0.46 g/l and 1.1 g/l, respectively. Concentration of 1.6 g/l nanochitosan completely inhibited the growth of C. acutatum L2. In in vivo, nanochitosan could control the growth of C. acutatum L2 on tomato fruits. After 10 days, the nanochitosan concentration of 4 g/l inhibited 76% the development of lesion diameter and MIC50 was achieved at concentration of 1.14 g/l.

Effects of Plant Growth Regulators and Micronutrients on In vitro Growth and Flowering in Roses

Thu, 19 Oct 2017 17:18:29 +0700

An in vitro flowering system has been considered as a convenient tool not only to study flowering mechanism but also to produce commercial in vitro flowers. This study evaluated effect of plant growth regulators (BA and TDZ), AgNO₃ and CoCl₂ on growth and in vitro flowering of three rose varieties (HV, HD, HT). The results showed that all tested compounds had different effects on plant growth but only TDZ and AgNO₃ were able to induce flowering. On MS medium containing 0.2 mg/l TDZ, only HV variety was induced flowering with the rate of 72.2%, while on medium supplemented 30 μM AgNO₃, after 21-25 days, all three varieties HT, HV and HD were induced flowering with the rates of 30%, 40% and 50%, respectively; the flowers lasted as long as 14-16 days.

The Indispensability on Restructuring of Agricultural Economic in Direction of Commodity Production in Bokeo Province, Lao People’s Democratic Republic

Xaysongkhame Phimmasone, Nguyễn Hữu Ngoan — Thu, 19 Oct 2017 17:24:15 +0700

Bokeo province depends on the country of the Lao People’s Democratic Republic (Lao PDR), is located in the north of the country, it is a mountainous province which has many people of ethnic groups. In addition Bokeo has a lot of potential to develop agricultural commodity in terms of high production in a specialized one. However, in the past few years the production of agriculture in the province still has a condition of self-sufficient, lack of concentration, low labour capacity, there has not cultivated an advantage of the nature yet including socio-economic of the province to develop a base of agricultural commodity with high yielding, quality and high ability for competition. Therefore, it is needfully studying on basis theory and pratice deeply to be a scientific foundation in socio-economic development, especially on agriculture sector of the province. This paper emphasises on systematic basis of theory as same as to conduct a scientific foundation on practice for restructuring of agricultural economic in direction of commodity production in Bokeo province.

THE ASSESSMENT OF THE IMPACT OF INTERNATIONAL TRADE AND PROTECTION ON WAGES USING THAI MANUFACTURING SURVEYS

Tran Dang Quan, Nguyen Thi Thuong, Ta Quang Kien — Thu, 19 Oct 2017 17:32:45 +0700

The study assessed the impact of international trade and protection on wages across Thai manufacturing industries for years 2000, 2001 and 2003. The authors adopted the literature regressions of this impact on the individual wages based on their characteristics across manufacturing industries. Following this line, the authors proposed estimation for manufactory average wages under control of heterogeneous manufactories by both manufactory and industry characteristics. The authors addressed differences in wages between trading and nontrading (imports or exports) manufactories. Imports and exports were measurements of international trade; tariffs and non-tariff barriers (NTBs) were protection indicators treated as endogenous. The results showed that workers in unprotected, exportable manufacturing industries were paid higher wages than workers in protected industries with similar observable manufactory and industry characteristics. In details, tariffs and NTBs were negatively significant effects on wages. These results are consistent with the previous literatures and of significance to Thai economy.

Estimating Environmental Efficiency for Agricultural Production: A Case Study of Rice

Võ Hồng Tú — Thu, 19 Oct 2017 17:36:50 +0700

The paper introduced a methodology to estimate environmental efficiency for agricultural production by applying stochastic frontier analysis. The results estimated from this method are reliable and applicaple in reality because the method can separate noise effects from deterministic frontier and ensures the independent distribution of technical and environmental efficiency scores. The so-called environmental efficiency was defined as the ability to reduce environmentally detrimental inputs while keeping other observed inputs and output level constant. The environmental efficiency is a promising and empirical indicator for producers, consumers and decision makers to arrive atproper solutions or interventions that promote the harmonious development respecting the environment. The paper also provided an example of 199 rice farmers in An Giang province in 2014 to demonstrate the detailed steps of the measurement. The results showed that the average technical efficiency and environmental efficiency were 93.16% and 77.70%, respectively. In all cases, the environmental efficiency scores were smaller than those of the technical efficiency.