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Evaluation of automated anaerobic fermentation processes as in the case of mould infected maize
81-86Views:193In Hungary the renewable energy utilization is planned to achieve 13% by 2020. Biogas production is one of the fields with the largest energy potential. Achieving high efficiency during continuous production despite the mixed and variable composition of input materials is the most common problem which the newly built biogas plants using agricultural raw materials have to deal with. The first experimental reactors at the Department of Water and Environmental Management were built 12 years ago. Control and automation of the four separated bioreactors were executed with ADVANTECH GENIE 3.0 software which granted pre-programmed measurement and points of intervention for pH, temperature, CH4, CO2, H2S, and NH3. The system became out-of-data, therefore in 2010 it has been redesigned and tested. The system is controlled by Compair Proview SCADA (Supervisory Control and Data Acquisition) software running on Linux platforms. The Fusarium infection caused serious yield-losses in cereal production in 2010. In the case of cereal products, which non-utilizable as forage seems an optimal solution is utilizing as biogas raw material. The raw material was based on the Fusarium infected maize. In the recent publication infotechnological and technological experiences of the pilot test period are evaluated as well as direction of future development is defined.
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Ecotoxicological impact of DON toxin on maize (Zea mays L.) germination
35-40Views:210Fusarium graminearum is one of the most significant arable pathogen in Hungary, and various types of trichothecene mycotoxins (mostly DON, deoxynivalenol) are detected most commonly in cereals (Biró et al., 2011). Fusarium infection and mycotoxin production could not be eliminated, and infected maize by Fusarium sp. cannot be exploited as food, seed, or animal feed. However it can be raw material of biogas production. In this research we would like to investigate the content and effect of the toxin in the end product of biogas production on plant germination. The Fusarium sp. can cause mildew and seedling mortality in seed of maize (Zea mays L.), so we examine the effect of this on germination. In preliminary examination Fusarium sp. was not detected in the bioreactor of the Institute after the retention time (30 day), however it can be assumed that during the hydrolysis of the fungus growth and mycotoxin production also increased exponentially. There were no appropriate tools to detect the toxin in the end product of biogas production so modelling of anaerobic hydrolysis was necessary. The effects of hydrolyzed product for germination were also detected.
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Using integrated remote sensing methods in the Nagyerdő Natura 2000 area
19-24Views:206The more widely use of GIS, remote sensing technology provides appropriate data acquisition and data processing tools to build several national and international biodiversity monitoring system of environmental protection and natur conservation. The ChangeHabitats 2 is a similar international project, which uses airborne hyperspectral and airborne laser scanning (airborne LiDAR) sources beyond traditional data collection methods to build a monitoring system of Natura 2000 habitats. The goal of our research, on one hand, was to separate the most typical species of trees which can be found in the largest coverage in the research plots of Debreceni Nagyerdő Nature Reserve from field and airborne remote sensing data, use image classification that based on spectral and geometry (height) characteristics of the trees. On the other hand our goal was to evaluate the efficient use of the integration of mobilGIS, airborne hyperspectral and airborne LiDAR data collecting methods to complement or substitut of the traditional, field data collecting methods. We used ArcGIS 10.2 and Exelis 5.0 GIS software for data evaluation, in which the mosaicing, the selection of plots and the spectral image processing were carried out.
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Applicability of precision weed detection technologies
163-168Views:218In an agricultural field or horticultural plantation, weeds compete with cultivated plants for water and nutrients. The transpirated water by the weeds is needed to be replaced, which saddles surplus costs on the farmer, which could reduce the profitability of crop production. The aim of the precision plant protection system is to protect cultivated plants by applying site-specific technologies and optimized herbicides combination and methods, without environmental damage. The first step of precision weed control is the scouting for weeds. Traditional and modern (passive and active remote sensing) weed surveying technologies are available to detect weeds. The examination was carried out in an intensive apple orchard with drip irrigation system, protected by hail net of the Study and Regional Research Farm of the University of Debrecen near Pallag. The spectral-based weed detection was worked out by the Tetracam ADC broadband multispectral camera and the GreenSeeker 505 vegetation indexmeter. A strong correlation observed between vegetation indices and weed coverage. Based on the collected data, weed maps are created in appropriate software environment, thus the spatial distributions of the weeds are determined. The species level discrimination and the recognition of weed structural parameters were executed based on the 3D point cloud data by Leica ScanStation C10 laser scanner.
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Testing laboratory parameters of compost tea
31-36Views:491During the industrial production of broiler chicken, a large amount of manure is produced, of which easily contained nitrogen content (without pre-treatment) is released into the atmosphere as an air pollutant. In our experiments, we aimed to prepare compost tea, also known as water extract of compost, from pre-treated poultry manure in order to create a product can be utilized as liquid nutrient supply. The poultry manure source was the Baromfi-Coop Ltd. located in Nyírjákó, Hungary, where it was treated by composting. As a result of this pre-treatment of the poultry manure, its nutrient parameters improve and nitrogen is present in a form that is better utilized for plants. Furthermore, this product is suitable for further utilization and also can be the base material for a brand-new product. For this reason the effects of compost/water ratio, incubation time, low oxygen level, and extraction time on the parameters of the resulted product were studied in the frame of developing new soil-life enhancing microbial product, so-called compost tea.
Chemical parameters of the compost used as base material strongly determined the properties of the resulted compost tea, especially the ratio of the various nitrogen forms, their concentration and the salt content. It was found that adding water at a higher rate that means 1/40 and 1/50 mixing ratios results in more cost-effective production. In the experiment the compost tea were held under oxygen-poor conditions, therefore pH of the extractions decreased, which influenced the quality and quantity of their nutrient content.
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Comparison of Pálfai’s drought index and the Normalised Precipitation Index in the North Great Plain region
59-64Views:229Agriculture has always been an important role in economy, food supplies, sustainability of society and creation of job opportunities in Hungary. Our country has resource-related strength of agriculture, because we have more than 4.5 million ha for agricultural production. Agricultural production can be influenced by several factors, including climate, hydrology, soil conditions and antropogenic impacts. Climate determines the quality and quantity of the crop yields. The climate conditions in Hungary are variable and it shows spatial and temporal extremes. As a result of this, drought have become more frequent in our country (2003, 2007, 2009, 2012), which is reflected in the decline in yields as well. In the present study, Pálfai's Drought Index (PAI) and the Standardized Precipitation Index (SPI) were compared 2003–2012 in Debrecen. The temperature and precipitation data were calculated from data provided by a local meteorological station to work out PAI, while the SPI-3 index values were downloaded from the database of the European Drought Observatory. This allowed to drought assessment in a local and regional scale. Our study was supplemented with SPI-3, soil moisture anomalies, PAI and yields of wheat (Triticum aestivum L.) and maize (Zea mays L.) to evaluating the impact of drought on agriculture.
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Comparing the yield of maize (Zea mays L.) hybrids in organic and conventional agriculture
13-17Views:177The European Green Deal was published by the European Commission in 2019. The main aim of the program is to reach net zero greenhouse gas emissions by 2050, making Europe the first climate-neutral continent in the world. To achieve this, criteria are also set for agriculture: increasing the share of land under organic farming to 25%, reducing the use of fertilisers and pesticides. However, the benefits of organic farming are widely debated. The aim of our study was to compare the yield of maize (Zea mays L.) hybrids bred in Martonvasar in two different cropping environments. The silage yields of 20 different maize hybrids were evaluated in a three replicate small plot experiment in an organic field and an adjacent conventional field. The average green mass yield of the hybrids was 36,58 t ha-1 in the organic field and 43,03 t ha-1 in the conventional. The green mass yield in the organic area was 20% lower than in the conventional area, and the dry matter yield and digestible dry matter yield were about 18% lower. Hybrids of different maturity groups responded differently to organic cultivation. The yields of early hybrids decreased more and late hybrids less in the organic farming compared to the conventional production.
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Spectral analysis of stress symptoms caused by apple powdery mildew (Podosphaera leucotricha
83-88Views:216An orchard can be examined on the basis of spectral data, using methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Calculated on the basis of such hyperspectral data from different index numbers the water supply of foliage conditions can be well characterized.
The research site is an intensive apple orchard, which located in University of Debrecen, Agricultural Sciences Centre, Farm and Regional Research Institute at Pallag. During my experiments the preliminary evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by Podosphaera leucotricha.
Based on the results narrow band greenness indices (NDVI705, mNDVI705, mSR705 and REP) can be used for determination of diseased canopy and for the detection of stress symptoms of Podosphaera leucotricha,. These statements can be utilized in precision plant protection systems, since it can be a basis for such integrated active sensors with LED or laser light source, measuring reflectance at the certain spectral range, which can facilitate real time status assessment of orchards and can control precision fungicide utilization.
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Examination of the conditions of extreme water balance circumstances (water logging, drought) with environmental information technology tools
79-86Views:239The Carpathian Basin is characterized by varying hydrological extremes, both in space and time. Hungary's natural endowments are more favourable than average, especially for agricultural production, with 5,3 million hectares of land we have which is suitable for agricultural production. These extreme water management are often occur in the same year and mostly in the same region, which may become more frequent in the future, especially in the lowland regions. The negative impacts of extreme water management was influenced by the land use changes in recent years, which has modified the runoff processes of the affected regions.
The aim of the study was to research the formation of inland water and drought circumstances in two sample areas the Great Plain (Szolnok-Túri flat and Nyírség) by geoinformatic tools. During the investigation in the first step we determined that areas which are susceptible to inland water and drought, based on the AGROTOPO database. In addition, land-use categories of characteristics of the sample areas are evaluated according to the Corine Land Cover. Furthermore, after defining characteristic of NDVI values between the period of 2003–2013, we evaluated the effect of drought whether can be detected in crop failures in respective areas.
Based on our results, we concluded that the formation of inland water and drought circumstances can be investigated in a large spatial extension by geoinformatic tools and databases.
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Modelling forestation alternatives
35-41Views:240Agroforestry systems are part of the history of the European Union rural landscapes, but the regional increase of size of agricultural parcels had a significant effect on European land use in the 20th century, thereby it has radically reduced the coverage of natural forest. However, this cause conflicts between interest of agricultural and forestry sectors. The agroforestry land uses could be a solution of this conflict management. One real – ecological – problem with the remnant forests and new forest plantation is the partly missing of network function without connecting ecological green corridors, the other problem is verifiability for the agroforestry payment system, monitoring the arable lands and plantations.
Remote sensing methods are currently used to supervise European Union payments. Nowadays, next to use satellite imagery the airborne hyperspectral and LiDAR (Light Detection And Ranging) remote sensing technologies are becoming more widespread use for nature, environmental, forest, agriculture protection, conservation and monitoring and it is an effective tool for monitoring biomass production.
In this Hungarian case study we made a Spatial Decision Support System (SDSS) to create agroforestry site selection model. The aim of model building was to ensure the continuity of ecological green corridors, maintain the appropriate land use of regional endowments. The investigation tool was the more widely used hyperspectral and airborne LiDAR remote sensing technologies which can provide appropriate data acquisition and data processing tools to build a decision support system.
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Evaluation of the blood product characteristics of meat meal and hemoglobin with non-invasive methods in the VISNIR wavelength
49-56Views:264The separate collection of poultry slaughterhouse trimmings and blood is partially solved in Hungary. Only properly prepared animal by-products, protein meals can be utilized as animal feed additive. However, different protein meals are appropriate for feeding different animal species. That is the reason why it is important to avoid accidental cross contamination of the products. Meat and blood meal produced on the same technological line, therefore mixing of the products can happen in various proportions during the shift of production.
Thus the aim of this study is to develop a spectral method which will allow to estimate the ratio of meat and blood protein meal in the final product. During the test the products were mixed in different proportions and were examined by the spectral method. Measurements were conducted with AvaSpec 2048 spectrometer in visible (VIS) and in near infrared (NIR) wavelength range (400–1000 nm) to define the spectral differentiation of the different meal products. Significant difference can be detected in spectral reflectance between the meat and blood product in the VIS-NIR range. The blood product has a characteristic spectral property: in the range of 600 and 735 nm reflectance values are increasing following a sigmoid curve. This property is not observed in the case of meat meal: close to linear rising is detected. Effective protein rate and purity detection could be made by Blood Product Sensitive Mixing Index (BPSMI – R930/R600), and by the calculation of inflection point in 600–735 nm.
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Saccharomyces cerevisiae growth kinetics study dairy byproduct
169-172Views:243By guess, annual volume of milk whey is 185–190 million tons and this volume probably will increase next years. Whey has significant biochemical oxygen demand due to its high organic matter content so whey as sewage is one of the most pollutant by-products in the food industry. Apart from environmental pollution, benefit of several whey constituents for human health is another reason to utilize whey. Corn and potato, as well as the processing of milk in the food industry in large quantities of by-products generated by low cost, substantial quantities of starch and lactic acid, which are due to high biological oxygen demand are considered as hazardous waste. Some of them are destroyed sewage storage tanks, and those products are excellent substrates for the growth of microorganisms could be. The traditional nutrient solution optimization methods are solution and time-consuming and are not able to determine the real optimum because of the interaction of factors involved.
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Effect of compost/water ratio on some main parameter of compost solutions
117-121Views:270Composting is an efficient technology for the utilisation of by-products and waste. It is also suitable for treating raw materials to convert fertilisers that are not recommended for application without pre-processing. Such is the case with poultry manure, which is very important to pre-treat due to its hazardous properties. An increasingly common form of compost is compost tea, which is made by soaking compost in water. In our experiment, we made compost tea from a composted and granulated poultry manure product. Three mixing ratios were used (1/5, 1/10, 1/10) and compost teas were set for three different extraction times (24–48–72 hours). After elimination of the experiment, the pH, EC, and nitrate and ammonium contents of the samples were measured. The aim of this study was to determine whether there is a difference between each mixing ratio and different extraction times. Based on our results, it can be said that the fluctuation of pH values during the experiment was low. Regardless of the mixing ratio and extraction time, the samples were in the slightly acidic range. The electrical conductivity, nitrate and ammonium content follow a similar trend, the values decrease significantly with the increase of the mixing ratio. Similar tendency was observed at the incubation time. The concentrations of both EC and nitrogen forms increase with increasing incubation time, in most cases significantly.
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Study on the cold tolerance of maize (Zea mays L.) inbred lines in Phytotron
41-45Views:109Maize has come a long way from the tropics to the temperate zone. In the beginning, the spreading of maize was prevented by its sensitivity to cold. Improved cold tolerance at germination is one of the most important conditions for early sowing. The advantage of cold tolerant hybrids is that they can be sown earlier, allowing longer growing seasons and higher yields, due to the fact that the most sensitive period in terms of water requirements, flowering, takes place earlier, i.e. before the onset of summer drought and heat.
In Martonvásár, continuous research is carried out to improve the cold tolerance of maize. In the present experiment, the cold tolerance of 30 genetically different maize inbred lines was investigated in a Phytotron climate chamber (PGV-36). The aim of our research is to identify cold tolerant lines that can be used as parental components to produce proper cold tolerant hybrids and/or as sources of starting materials for new cold tolerant inbred lines. After observing and evaluating changes in phenological traits under cold-test, the results of the cold-tolerance traits of interest have been used to highlight several inbred lines that could be good starting materials for further research on genetic selection for cold tolerance.
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Horticulture applicability of 3D laser scanner
75-78Views:228As a result of the technological development, remote sensing instruments and methods have become widespread in all segments of life (from precision agriculture through architecture to medicine). Among the innovative development of remote sensing instruments the 3D laser scanner is overriding importance. The horticulture applicability of terrestrial laser scanning technique is innovation in the precision agriculture, because it could be determine the structure of trees and branches, the canopy extension, which can help to recognize some biophysical parameters. The examination was carried out with Leica ScanStation C10 terrestrial laser scanner in the Study and Regional Research Farm of the University of Debrecen near Pallag. In this article I present the measuring principle, the parameters and horticulture applicability of the terrestrial laser scanner.
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Examination of the effect of pelleted poultry manure products on a sunflower test plant in a laboratory model experiment
83-88Views:247Sunflower (Helianthus annuus L.) is one of the most important oil plants in Hungary, with a sown area of more than 627.000 ha in 2019. Sunflower cultivation is primarily important for use in the oil industry, but its role in feed and beekeeping cannot be neglected either. Sunflower adapts well to different production areas in terms of soil demand, yet, as important fact, it must be grown on soils with poorer conditions with intensive nutrient replenishment. From the agri-environmental point of view, in addition to the use of pelleted poultry manure products, which are also new to the consumer market, is of paramount importance. Their advantages include a wide range of nutrients as well as a soil structure improving effect.
In our research, we investigated the starter effect of pelleted poultry manure products applied at different doses (200 kg ha-1 and 400 kg ha-1) on sandy soil with humus using a sunflower plant. The aim of our research to investigate the effect of using pelleted fertilizer products as starter fertilizers on sunflower plant germination, and investigate the effect of poultry manure products on soils.
Based on our results, it can be stated that the pigment content (chlorophyll and carotenoid content) was positively influenced by the higher dose treatments (400 kg ha-1), thus increasing the photosynthetically active leaf area. Compared to the control, the carotenoid content in the test plants of the treatments increased, and the differences of this treatment proved to be significant (p<0.05). Our experiments supported the beneficial effect of pelleted poultry manure-based products in the soil-plant system.
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Effects of fermented chicken manure products on the N mineralization rate of the soil using the incubation method
199-204Views:199In our study, the effect of fermented and specially added poultry manure products (superabsorbent polymer (SAP), bentonite and Aegis as a mycorrhizal inoculum) were investigated in a short soil incubation experiment – at 60% water capacity level - on sandy soil. Soil samples were collected from two layers of the incubation pots after the second and fourth week to check the status of the tested products and the processes in the soil. The pH and the electric conductivity (EC) of the samples were measured using an electrochemical method, while the ammonium and nitrate content of the samples was determined with a photometric method. Soil pH and EC values slightly were decreased during the experiment. Our results pointed out that the increasing dose of SAP caused lower soil pH. The nitrate content of the soil did not change significantly during the experiment. It was found that the increasing SAP content in the products, due to its cross-linked structural property, protected the nitrate ions from leaching. Our results suggest that applied SAP does not bind the nutrient ions so tightly in its structure that it competes with the plant for uptake.
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Effects of fermented and supplemented chicken manure on the nutrient management aspects of an apple orchard
117-123Views:145AIt is a huge challenge for farmers worldwide to successfully increase the organic matter content of their soils and improve their water balance at the same time. Therefore, the main aim of the study is to develop and test organic-based nutrient composite materials that can be successfully used by farmers to increase soil organic matter content, improve water management parameters and implement water-efficient technologies. The study was performed in the orchard of the Institute of Horticultural Science of the University of Debrecen in Hungary (Debrecen-Pallag). The experiment was set up in a ten-year-old apple (Malus domestica ‘Pinova’) orchard. In the trial, fermented poultry manure and superabsorbent polymers (SAP) were used at different doses to study their effects on soil properties and fruit quality. Applied composite materials increased the nitrate and organic nitrogen content of the soil. Treatments did not affect the sugar content of the fruits but significantly and positively affected the individual fruit weight and the titratable acidity of the fruits.
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Early evaluation of use of fermented chicken manure products in practice of apple nutrient management
195-198Views:183According to the Green Deal efforts, the importance and relevance of organic fertilization will increase in the near future. Therefore, the investigation of the effects of different organic fertilizers on soil productivity and nutrient supply is a priority area of agricultural research. Organic fertilizer experiment was conducted in an eight-year-old apple (Malus domestica Borkh.) orchard at Debrecen-Pallag. In the trial Pinova cultivar was used. In this study, two different fermented chicken manure products were added to the soil (in 20 cm depth) to test their effects on soil nutrient status, plant uptake and fruit quality. It was found that the applied treatments slightly increased the pH and nutrient levels in almost all cases, but significant effect was not observed in all treatments compared to the control. Leaf nutrient contents (N, P, K, Ca and Mg) were measured in the experiment. Leaf nutrient status was not affected by the fermented chicken manure treatments. However, used treatments had strong effects on the fruit characteristics and inner parameters, such as fruit diameter and Brix value. Moreover, it was established that the applied organic fertilizers increased the yield significantly.
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Pre-treatment of wastes containing keratin in industrial conditions
59-64Views:159The aim of the research was a development of a featherdegradation technology in industrial circumstances. During the experiments we determined the parameters of the critical environmental and technological limitation factors. Because of the high keratin-content the degradation (and composting) of the feather is difficult. With the developed technology huge mass of feather can be used fast and easily in biogas production and in the adjustment of the optimal element ratio of biomass. The industrial experiments were implemented in a 6m3 heatable double-walled
tank with stirring-shovels and aeration-system. The degradation process was followed with extinction measurements.
According to the experiments that were done the best results were given at the case which was heat-treated at 70°C, was injected with 1% bacteria concentration, and where 1:3 feather:water ratio was set if we consider the effectiveness of degradation and the hydraulical retention time. -
Mitigation of environment impact of mycotoxins produced by Fusarium species
159-164Views:183The Fusarium fungi hazards the grain quality of cereals, therefore significantly affects their utilization as animal feed or consumable product. The Fusarium can decrease the quality of wheat in different ways: decreases the germination capability, causes visible discoloration, mould may appear, reduces the dry material and nutrient content of the grain, causes mycotoxin infection – as a result given by its by-product. Micotoxins produced by Fusarium genus, as the trichotecenes (T-2, HT-2, deoxynivalenol, nivalenol, diacetoxyscirpenol, Fusarenone-X) and the zearalenone (F-2) are the most common in Hungary. Occurrence of fumonisins first discovered in 1988 are must be identified carefully. About 20–30% of the overall worldwide production of cereals is infected with Fusarium and its toxins, which situation is similar in Hungary. This infection causes serious yield-losses in cereal production. In the case of cereal products, which non-utilizable as forage seems, an optimal solution is utilizing as biogas raw material, but it is also important to examine the effect of the infected cereal on the anaerobe digestion process.
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Risk effects of the spread route of mycotoxins
90-95Views:161In Hungary the mycotoxin is a great problem, because there are many natural toxins in wheat and maize. These cereals can be found on
considerable proportion of the country’s sowing area, and they are deterministic food for the population. The direct human and animal
utilization of the contaminated cereals mean a serious risk in the food chain. In Hungary’s climate the soil is contaminated with pathogen
moulds, particularly Fusarium species, which increase by respective temperature and moisture content in cereals. The Fusarium can
decrease the quality of the wheat in different ways: decrease the germination capability and cause visible discoloration and appearance of
mould, reduces the dry material and nutrient content of the grain. From the toxins produced by the Fusarium genus, the trichotecene (T-2,
HT-2, deoxinivalenol, nivalenol, diacetoxyscxirpenol, Fusarenon-X) and the estrogenic zearalenon (F-2) are the most common in Hungary.
The fumonisins (FB1, FB2, FB3) first identified in 1988, relatively newly discovered, are also important. Major proportion of mycotoxins in a
healthy organization is metabolized by the enzyme system of liver and intestinal bacteria. The toxicity is reduced or even leaves off.
However, more toxic and biologically active compounds can be formed. For the reduction of mycotoxin-contamination several possibilities
are available in the case of storage, processing and feeding. -
Utilization of the field experiment results of University of Debrecen in the development of maize-based bio-ethanol production
55-57Views:157Maize is currently the single raw material of bio-ethanol production in Hungary. The aim of our examinations is the observation of yield and
nutritional characteristics of commercial maize hybrids in Hungary from the aspect of efficient bio-ethanol production. We set up a
randomized block field trial. We determined the starch content and starch yield (t ha-1) of the 51 maize hybrids involved in the field trial.
In laboratory conditions, we examined the amylose and amylopectin ratio and the amount of resistant starch of the selected 20 maize hybrids.
According to our results, there is a significant difference between the starch yield the amylose component of the starch content and resistant starch of the examined maize hybrids. Our studies reveal that maize as a raw material must be selected based on the cultivation objectives. If the objective is bio-ethanol production, detailed knowledge of starch content is necessary. There is a significant difference among commercial maize hybrids in Hungary in terms of characteristics determining the producible amount of bio-ethanol. -
Spatial Relationships Between pH and Vegetation Pattern in an Area Contaminated with Heavy Metals
140-143Views:102It is not possible to gain information on the risk factor representing the bioavailability and the mobility of the contaminants only on the basis of their total concentrations. Especially, in case of heavy metals, which can be charaterised with very different chemical forms and their mobil and mobilizable parts are determined by complex balances highly sensitive to the changing environmental conditions. Considering mine tailings, however, the toxic elements are basically in ore forms having low adsorption capacity, thus the heavy metal ion concentration in solution is governed mainly by the pH conditions. In Gyöngyösoroszi, the spatial distribution of the total heavy metal concentrations as well as that of pH values determining the bioavailable part of the toxic elements were estimated and by mapping the vegetation pattern, relationship was analysed among the total Zn, Cu, Pb and As concentrations, the pH and the species present. Results show that the presence of the certain plant species is highly determined by the pH on the mine tailing material, the highest vegetation density was found where the bioavailability of the toxic elements were considered the smallest as a result of the neutral pH. As a result, high diversity could be found even in places where the total zinc, copper, lead and arsenic concentrations were extreme. In addition, plant species could be identified, which are tolerant to toxic elements and present even if the pH is low and the bioavailable part of the heavy metals is relatively high.
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Examination of resistance against Aeromonas hydrophila infection on genetically different common carp variants (preliminary results)
7-11Views:95Septicemia disease caused by the bacterium Aeromonas hydrophila is a major problem for fish farmers around the world. In our experiment resistance to the disease was investigated on carp variants with diferent genetical backgrounds. 96 different genetic variants(„families”) were created by crossing various individuals of 4 carp strains (2 wild and 2 cultured ones). Families were reared until reaching the size of 10 gramms and 100 fish of each families were marked with an individual electronic identifier. Marked fish were divided into 5 groups. Fish from one group were infected with A. hydrophila and mortality were registered during 2 weeks. Based on mortality data, the most resistant and most susceptible families will be selected using population genetics methods.