FOOD SAFETY STANDARDS AND REGULATORY MEASURES: IMPLICATIONS FOR SELECTED FISH EXPORTING ASIAN COUNTRIES     

Madan M. Dey  M. A. Rab  K. M. Jahan  A. Nisapa  A. Kumar  M. Ahmed 《Aquaculture Economics & Management (Blackwell Science)》2013,17(1-2):217-236

ABSTRACT

Developing Asian countries continue to record an impressive trade surplus in fish products. However, raising consumer concerns about a range of food safety matters and increasingly stringent regulatory standards related to fish product supply pose on-going challenges to the sustained international market access of many developing country suppliers. This paper provides an overview of emerging trade patterns in fish products and the trade regime in which this is occurring. It then reviews the implementation of various food safety standards on fish and seafood exports in the major fish-exporting countries in Asia, and analyzes the costs and benefits of compliance with these standards and regulations in these countries. Results show that, at the factory level, implementation of the standards has significantly increased the cost of processing, and the cost per unit of fish processed is higher for the smaller plants. These economies of scale could exclude small operators in developing countries. Continued competitiveness of small plants would seem to require government policies and support designed to minimize the cost of compliance with international standards.  相似文献   

Optimizing protocol for efficient microspore embryogenesis and doubled haploid development in different maturity groups of cauliflower (B. oleracea var. botrytis L.) in India     

R. Bhatia  S. S. Dey  Shritika Sood  Kanika Sharma  V. K. Sharma  Chander Parkash  Raj Kumar 《Euphytica》2016,208(3):439-451

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Effect of midstory and understory removal on the establishment and development of natural and artificial pin oak advance reproduction in bottomland forests   总被引：1，自引：1，他引：0  

Jonathan R. Motsinger  John M. Kabrick  Daniel C. Dey  Dawn E. Henderson  Eric K. Zenner 《New Forests》2010,39(2):195-213

Regenerating oaks (Quercus L.) on mesic and hydric sites has remained a problem largely because of inadequate density and poor distribution of large oak advance reproduction prior to harvesting. We examined the effect of midstory and understory removal on the establishment and 3-year development of natural and artificial sources of pin oak (Q. palustris Muenchh.) advance reproduction in bottomland forests in southeastern Missouri, USA. Midstory and understory removals increased the photosynthetically-active radiation (PAR) reaching the seedling layer from about 3 to 15%. This increased light did not increase the density of natural pin oak advance reproduction compared to control, but it increased the survival and nominally increased the growth of the natural pin oak advance reproduction. Where the midstory and understory had been removed, underplanted RPM^® container stock and bareroot pin oak stock maintained high survival, but of the two only the RPM^® stock maintained positive height and diameter growth while bareroot stock suffered some growth reductions. Pin oaks originating from the direct seeding of stratified acorns sown in the spring had low germination and survival, but the survivors had growth rates similar to those of natural seedlings in thinned stands. Applying triclopyr to competitors in the ground flora layer only nominally increased PAR but reduced the percent survival and marginally increased the growth of natural and artificial pin oak. We conclude that artificial reproduction may be used to further increase the probability of achieving adequate numbers of the desired species in the future. Bareroot seedlings may not perform as well as RPM^® seedlings and natural seedlings already present. However, bareroot and RPM^® seedlings remained significantly larger than the natural seedlings after 3 years.  相似文献   

Effect of fire severity on physical and biochemical soil properties in Zagros oak (<Emphasis Type="Italic">Quercus brantii</Emphasis> Lindl.) forests in Iran     

M. Heydari  A. Rostamy  F. Najafi  D. C. Dey 《林业研究》2017,28(1):95-104

Fire affects the physical and chemical properties and soil biological activity of natural ecosystems. This study was conducted in the Miyan Tang region, Ilam Province in western Iran. The study site was 110 hectares, where we sampled soils in areas that were classified by fire severity: low (LS), high (HS) and medium severity (MS), and unburned (UB), which served as the control. In each severity class, 25 transect points were randomly selected for measurement. Around each transect plot center, 3 soil samples were selected randomly and soils collected from the 0 to 20 cm depth were combined into a composite sample that was used in laboratory analysis to represent conditions at that point. Plots in the UB and LS fire classes had similar soil conditions and had higher values of factors such as saturated moisture, organic carbon, carbon dioxide, and silt and clay content. In contrast, plots in the HS and MS fire severity classes were clustered in the positive direction along the first axis that represented gradients in soil acidity, electrical conductivity, cation exchange capacity, accessible phosphorus, accessible potassium, bulk density, and sand. Soil attributes were similar in areas of HS and MS fire severity classes, whereas soil conditions in the LS class and UB controls were most similar. Fire in the LS areas either did not significantly alter the physical–chemical soil properties and microbial basal respiration, or soils were able to recover quickly after being burned.  相似文献   

Isolation of anacardic acid from natural cashew nut shell liquid (CNSL) using supercritical carbon dioxide     

Philip JY  Da Cruz Francisco J  Dey ES  Buchweishaija J  Mkayula LL  Ye L 《Journal of agricultural and food chemistry》2008,56(20):9350-9354

Solvent extracted cashew nut shell liquid (CNSL), conventionally known as natural CNSL, is a mixture of several alkenyl phenols. One of these alkenyl phenols is anacardic acid, which is present at the highest concentration. In view of anticipated industrial applications of anacardic acid, the objective of this work was to isolate anacardic acid from natural CNSL by supercritical carbon dioxide (scCO 2). In this study, the solubility data for natural CNSL in scCO 2 under a range of operating conditions of pressure (100, 200, and 300 bar), temperature (40 and 50 degrees C), and CO 2 flow rate (5, 10, and 15 g min (-1)) were established. The best scCO 2 working conditions were found to be 50 degrees C and 300 bar at a flow rate of 5 g min (-1) CO 2. Using 3 g of sample (CNSL/solid adsorbent = 1/2) under these scCO 2 conditions, it was possible to quantitatively isolate high purity anacardic acid from crude natural CNSL (82% of total anacardic acid) within 150 min. The anacardic acid isolated by scCO 2 was analyzed by different spectroscopic techniques (UV-vis, FT-IR, and (1)H NMR) and HPLC analysis, indicating that the anacardic acid isolated by scCO 2 has better quality than that obtained through a conventional method involving several chemical conversion steps.  相似文献   

Influence of overstory density on ecophysiology of red oak (Quercus rubra) and sugar maple (Acer saccharum) seedlings in central Ontario shelterwoods     

Parker WC  Dey DC 《Tree physiology》2008,28(5):797-804

A field experiment was established in a second-growth hardwood forest dominated by red oak (Quercus rubra L.) to examine the effects of shelterwood overstory density on leaf gas exchange and seedling water status of planted red oak, naturally regenerated red oak and sugar maple (Acer saccharum Marsh.) seedlings during the first growing season following harvest. Canopy cover of uncut control stands and moderate and light shelterwoods averaged 97, 80 and 49%, respectively. Understory light and vapor pressure deficit (VPD) strongly influenced gas exchange responses to overstory reduction. Increased irradiance beneath the shelterwoods significantly increased net photosynthesis (P(n)) and leaf conductance to water vapor (G(wv)) of red oak and maple seedlings; however, P(n) and G(wv) of planted and naturally regenerated red oak seedlings were two to three times higher than those of sugar maple seedlings in both partial harvest treatments, due in large part to decreased stomatal limitation of gas exchange in red oak as a result of increased VPD in the shelterwoods. In both species, seedling water status was higher in the partial harvest treatments, as reflected by the higher predawn leaf water potential and seedling water-use efficiency in seedlings in shelterwoods than in uncut stands. Within a treatment, planted and natural red oak seedlings exhibited similar leaf gas exchange rates and water status, indicating little adverse physiological effect of transplanting. We conclude that the use of shelterwoods favors photosynthetic potential of red oak over sugar maple, and should improve red oak regeneration in Ontario.  相似文献   

A suggested approach for design of oak (<Emphasis Type="Italic">Quercus</Emphasis> L.) regeneration research considering regional differences     

Daniel C. Dey  Martin A. Spetich  Dale R. Weigel  Paul S. Johnson  David L. Graney  John M. Kabrick 《New Forests》2009,37(2):123-135

Research on oak (Quercus L.) regeneration has generally consisted of small-scale studies of treatments designed to favor oak, including consideration of site quality and topographic effects on oak regeneration. However, these experiments have not consistently factored in broader-scale ecological differences found in the eastern United States. Oak regeneration experiments should be replicated at appropriate ecological scales to address the similarities and differences in regeneration following prescribed silvicultural treatments among ecological units. Patterns in oak regeneration can be better understood in an ecological context by considering how oak species interact in the differing physical environments and are able to maintain dominance in changing complexes of competing vegetation among the selected eco-units. Our understanding of oak regeneration response to specific silvicultural practices and our ability to model regeneration is improved when we use replication, blocking, or factorial deployment of relatively small-scale (0.5–1.0 ha) treatment plots within an ecological classification system. We present an example of this approach to understanding oak regeneration dynamics in a synthesis of research to regenerate northern red oak (Quercus rubra L.) by underplanting shelterwoods in Arkansas, Missouri and Indiana. We summarize important considerations to guide the design of future research in oak regeneration. Paul S. Johnson and David L. Graney—Retired U.S. Forest Service scientists.  相似文献   

Genetic analysis of important antioxidant compounds in cabbage (Brassiaca oleracea var. capitata L.)     

Chander Parkash  Sandeep Kumar  Nisha Thakur  Satish Kumar  S. S. Dey  Reeta Bhatia 《Journal of Crop Improvement》2017,31(3):418-437

The paucity of research on development of antioxidant-rich hybrids in cabbage by utilizing combining ability estimates, gene action, and heterosis motivated us to undertake this study. We made 60 crosses between 5 cytoplasmic male-sterile lines and 12 male-fertile testers during the summer of 2015, as per the line × tester design. The seedlings of all the parents and 60 F₁ crosses, along with three checks, were transplanted during the Rabi (winter) season of 2015–2016 and evaluated using a randomized complete-block design. Combining ability, gene action, and heterosis were determined for different antioxidant compounds. Experimental results revealed that the range of cupric ion reducing antioxidant capacity (CUPRAC) [parents = 1.26–7.33 and hybrids = 0.04–6.54 μmol trolox/g], ferric reducing ability of plasma (FRAP) [parents = 1.65–4.76 and hybrids = 0.16–4.67 μmol trolox/g], β-carotene (parents = 0.44–2.29 and hybrids = 0.04–1.89 μg/100 g), and chlorophyll-a (parents = 0.71–4.08 and hybrids = 0.19–3.08 mg/g f.w.) for hybrids was lower than that of the parents because of outbreeding depression. The parental lines 6A, 208A, 83-5-8, and Sel-5-83-6 were found to be good general combiners for most of the antioxidant compounds studied. Based on the mean performance, specific combining ability effects and heterosis, five hybrid combinations viz., 9A × KIRC-8 for CUPRAC and FRAP; 208A × C-122 for ascorbic acid; 6A × Chhaki-2 for total carotenoids and β-carotene; 831A × Chhaki-2 for chlorophyll-a; and 6A × 83-5-8 for chlorophyll-b and total chlorophyll content, were most promising. The ratio of general combining ability (GCA) and specific combining ability (SCA) variances, i.e., [2 σ²g/(2σ²g + σ²s)], which reflects the relative importance of GCA versus SCA, was less than unity for different antioxidant compounds, which implied that for these traits, nonadditive gene effects were more important than additive effects. The numerical values of range for contribution of lines × testers interaction for different traits (41.47–70.18%) were found to be higher than the individual contribution of lines (11.24–47.22%) and testers (8.31–21.76%). Hence, heterosis could be exploited for developing antioxidant-rich hybrid cabbage.  相似文献   

Phoma diseases: Epidemiology and control     

Debasish Deb  Ahamed Khan  Nrisingha Dey 《Plant pathology》2020,69(7):1203-1217

Phoma is the most widely distributed and omnipresent genus of the order Pleosporales and the largest genus with some 3,000 taxa described so far. Of these, approximately 110 species are pathogenic and occupy varied ecological niches. The genus Phoma is polyphyletic and is not really delimited, with unclear species boundaries that make it a taxonomically controversial genus. Fungi belonging to Phoma commonly occur on crop plants that are economically important, where they cause devastating plant diseases. Pathogenic members of Phoma sensu lato species attack crop plants with symptoms ranging from leaf blight to root rot, and even wilting of the plant. In infected crop residues and field stubbles, the pathogen produces abundant pycnidia and pseudothecia that serve as the source of primary inoculum, whilst repeated crops of conidia produced inside pycnidia are the main source of secondary infection during the same growing season. After successful infection, the pathogen produces various phytotoxins that alter photosynthetic efficiency and actin cytoskeleton-based functions, and cause electrolyte leakage from cells. Controlling the diseases caused by members of Phoma sensu lato is challenging and efforts have been made to identify resistant varieties that can be used in various plant breeding programmes. Studies have also been conducted to devise cultural and biological control measures as well as to evaluate the efficacy of fungicides against members of Phoma sensu lato. In this review we aim to discuss the disease epidemiology and control measures that can be practised to protect crops from Phoma diseases.  相似文献   

Determining critical limit of boron in soil for wheat (Triticum aestivum L.)     

Aritra Saha  Pabitra K. Mani  Gora Chand Hazra  Arup Dey  Shubhadip Dasgupta 《Journal of plant nutrition》2013,36(16):2091-2102

Abstract

Critical values of boron (B) for wheat nutrition in soil and plant were determined through a pot experiment with twenty-one surface soils of Alluvial flood plain and Red-latertic belt comprising three major soil orders (Entisols, Alfisols, Inceptisols) with four levels of boron. Application of boron significantly increased the dry matter yield as well as uptake of B by plants. Critical concentration of hot calcium chloride (CaCl₂) extractable B in soil for wheat was found to be 0.53?mg?kg^?1. The critical plant B concentration varied with growth stages and values were 7.4?mg?kg^?1 at panicle initiation and 4.18?mg?kg^?1 at maturity, respectively. The findings of this investigation also recommend the application of 2?kg?B^?1?ha^?1 for ensuring B sufficiency to wheat in Indo-gangetic alluvial and Red-Lateritic soils.  相似文献