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Effect of agrotechnical factors on the activity of urease enzyme in a long term fertlization experiment
43-48Views:126The soil is a natural resource, the fertility preservation is an important part of the sustainable development. We have to monitor the transformation dinamics of the organic nitrogen-containing substances, to get accurate information about the changes of the nitrogen cycle in the soil.
Physical and chemical properties of the soil and the microorganism effect on the organic matter in the soil – in addition to the composition of organic matter. Wide variety of extracellular enzymes are present in this decomposition. These enzymes help in the transformation of the macromolecules to transforming low molecular weight compounds so they will be available during the assimilation.
The urease enzyme, catalyzes the hydrolysis of urea to CO2 and NH3. The urease is widely spread in the nature, it is present in the microorganisms, plants and animals.
We found that the soil moisture content, the rotation and the fertilization affect to the amount of urease in spring. Furthermore, we get significant difference between the irrigated and non irrigated samples in the second period of the year. Based on our results we can state that the activity of urease was higher in spring 2014.
The objective of our study was to present how the different agronomic factors affect on the activity of urease in a long term fertilizationexperiment.
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Monitoring the oxygen level in the Szarvas-Kákafok Deadarm
170-173Views:58The water quality of the Szarvas-Békésszentandrás Dead Körös is generally meso-eutrophic, and meso-saprobic. However, particularly
under higher temperature conditions, the water body may change toward the eutrophic state, even algal blooms could be observed
previously.
The present measurements were conducted during a two week period, twice a day. Three water samples were taken horizontally, from
the surface, bottom and the middle of the water body. The samples were examined in situ. The oxygen content, the temperature, the pH and
the conductivity were measured by potentiometric methods.
Increasing pH was detected in correlation to the temperature, which indicated a rising photosynthetic activity. Also, the O2
concentration showed high variations, especially, when the fresh water supply from the river was stopped, due to a small flood in the river
Körös.
These results indicate the increasing eutrophication processes in the deadarm, and the high load and instability of the ecosystem. -
Effect of fish feeds with high vegetable oil and low fish oil content on the growth performance and innate immune system of common carp (preliminary results)
7-12Views:76Fish meal and fish oil are very important components of fish feeds used by aquaculture. They contain poly-unsaturated fatty acids, which are essential nutrients both for fish and human nutrition. However, sources of fish meal and fish oil are limited, there is a need for new feed components to supply the increasing fish production and the increasing demand for fish feed. The aim of AQUAMAX project, supported by the European Union is to replace the fish meal and fish oil with vegetable oils. As a participant of this project, group of immunology in Research
Institute for Fisheries, Aquaculture and Irrigation (HAKI) examined the effect of three different fish feeds on the growth performance, innate immune response and resistance against Aeromonas hydrophila infection of common carp in an in vivo experiment. Fish feed supplemented with Camelina oil, but still containing fish oil significantly increased growth performance of experimental fish and their resistance against the infection. Fish feed containing linseed oil only did not enhance the growth performance, and it had a negative effect on resistance against infection. Based on the experimental results it can be concluded that fish oil used in fish feeds cannot be replaced effectively with vegetable oils, but can be supplemented with them. -
Parameter optimization of an inductively coupled plasma mass spectrometer for measuring arsenic and selenium
81-85Views:143In the last decades, an increased interest has evolved in arsenic and selenium. The aim is to understand the environmental, agricultural and biological roles of these elements. In the case of arsenic, the major reasons are the relatively high concentration of arsenic in marine biota (mg kg-1) and the arsenic contaminated drinking water bases of some Asian countries, as well as Hungary. The toxicity of higher level selenium content is also known; nevertheless, selenium is essential for several biological functions. Considering its essentialness, in our country, the insufficient selenium intake rate causes a lack of selenium. Measuring the concentrations of these elements provides crucial, but unsatisfactory information, as the speciation, i.e. the form of an element presented in a sample is also required.
In both cases, the most suitable method to determine concentration is inductively coupled plasma mass spectrometry (ICP-MS). Our objective was to optimize the variable parameters of the ICP-MS to attain the lowest (the best) detection limit. For this purpose, we investigated the effect of parameter change on net signal intensity and relative signal intensity. With the optimized parameter settings, the limits of detection for arsenic and selenium were determined, which are 0,032 ng dm-3 for arsenic, and 0,097 ng dm-3 for selenium. -
Study of some physiologic properties of different genotype sweet corn hybrids
105-110Views:96The effect of nutrient-supply (control, N120+PK) and two different genotypes on the physiologic properties of sweet corn has been investigated in the crop-year of 2011 on chernozem soil in the Hajdúság region. The experiments were carried out at the Experimental Station of the University of Debrecen in Debrecen-Látókép. The experiment was sewn in two different sowing times: the 21st April can be considered as an early, while the 19th May as a late sowing time. The two involved hybrids were Jumbo and Enterprise. The applied plant density was 65 000 plants per hectare.
Our aim with this experiment was to study the plant production, just as the main affecting factors of its development and dynamics, like nutrient-supply and genotypes. We aimed to study and analyse the relationships between these factors and plant production. In this study following parameters were measured and calculated: photosynthetic activity, chlorophyll-content (SPAD-value), leaf area index (LAI) and leaf area duration (LAD). Regarding the analysis of photosynthetic activity values no obvious relationship between the measured values and the applied hybrids, just as nutrient-supply has been revealed.
Analysing the SPAD-values it can be stated that the chlorophyll-content of the measured leaves showed an increasing tendency due to the nutrient-supply. The highest values have been measured in the intensive cob development phase of the early sowing time plots.
Regarding the LAI-values we have found significant differences between the fertilizer treatments in both sowing time treatments. In case of the leaf area duration values – that is derived from the LAI values – nutrient-supply has positively affected the duration of the assimilation area. -
Agronomical and economic evaluation of various cultivation systems on meadow soil
103-106Views:103The requirements and objectives of cultivation are in constant change. There are different cultivation aims if the objective is soil protection, the prevention of its moisture content or on areas with different precipitation supply or production site endowments. Based on the experimental database of the Institute for Land Utilisation, Regional Development and Technology of the University of Debrecen, Centre for Agricultural and Applied Economic Sciences and the KITE Plc., the various cultivation systems in Hajdú-Bihar country were examined with maize as indicator plant. The sample area can be found in the outskirts of Biharnagybajom on meadow soil. On the examined plot, spring strip basic cultivation, loosening and autumn ploughing were applied on 15-15-15 ha, respectively. At the time of taking undisturbed soil samples, soil conductivity measurements were also performed with a Penetronik penetrometer. Undisturbed soil samples were taken from each treatment before sowing (on 5th April 2012). The yield obtained in the strip cultivation treatment increased that of the ploughing and the loosening technology. The economic indexes are the most favourable in the strip cultivation.
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The relationship between the nutrient supply and the yield of maize hybrids with different genetic traits on chernozem soil in variant years
27-31Views:187The experiments were set on lime-coated chernozem soil in 2013 and in 2014, in our study four hybrids were included with different FAO number. We studied the effect of NPK fertilization and row spacing on the yield. The fertilizer doses were based on a 25-year longterm experiment. Compared to control, the N40 +PK treatment has also achieved a significant yield increase, although some hybrids responsed with yield loss to the increasing fertilizer doses; this effect was observed especially in 2014. The majority of hybrids reached higher yields in both years using the 50 cm row spacing. The water release of hybrids was measured weekly during the maturation, at the same time points. The rainy September slowed ripening and the water release of the hybrids in 2013, so the grain wet content at harvest showed higher values. The moisture contents were increased for some hybrids, in spite of the positive and favorable dynamic of water loss.
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Genetic progress in winter wheat quality and quantity parameters
71-75Views:137Wheat production is significant branch of Hungarian crop production (with about 1 million hectares of sowing area). Weather anomalies resulted by climate change have increased the importance of biological basis in wheat production. Yield quality and quantity parameters of three wheat genotypes sown on chernozem soil type after maize pre-crop were studied in a long-term field experiment. Yield amount of the studied genotypes varied between 2894 and 8074 kg ha-1 in 2017 and between 5795 and 9547 kg ha-1 in 2018 depending on the applied treatments. Based on our results it can be stated that in both studied crop years the highest yield increment was realized by the application of the nutrient supply level of N30+PK. As the result of the application of the optimum mineral fertilizer level – in contrast to the control – resulted in significant yield increment in both crop years. The results of the long-term field experiment prove that water utilization of the studied wheat varieties / hybrids was improved by the application of the optimal nutrient supply. Furthermore, the water utilization of the latest genotypes was more favorable by both the control and the optimum nutrient supply level treatments. Analyzing the quality parameters of winter wheat using the NIR method it has been stated that the quality results of the well-known genotype (GK Öthalom) were better than those of the new genotypes. A negative correlation between winter wheat quality and quantity parameters has also been confirmed. As the result of the mineral fertilizer application protein and gluten content of winter wheat increased to a significant extent.
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A földhasználat alakulása az ezredfordulón - egy felmérés eredményei
58-66Views:82There were no significant changes in land ownership and use in 2000, compared to the period following the compensation process. Land is mainly owned by people who do not want to use their property, so they generally turn to renting it out to others. Although farming on rented land is performed under various conditions, farms try to rent the lands of better quality. In general, examined farms would like to increase their size by tenancy or land purchase. Buying land is a good investment, considering the price increase in the future, but because of the lack of capital, tenancy remains the main form of territory increase.
Farms which rent land are in connection with a lot of owners, the land within their use is frittered away, it is in a lot of parts. Most rental contracts are written, but the ratio of oral contracts is still quite high. To reduce this ratio is one future aim. One more characteristic of the rental contracts is the dominance of a medium length period – which is acceptable for both the owner and user, but the ratio of short time contracts is still high. Land rent, on average for the examined farms, is quite balanced, it is on the level of about 16.000 HUF/hectare.
The land users mainly pay the same land rent to the owners, but in some cases, there are exceptions. Generally, land rent is a fix cost, but sometimes this cost depends on the level of the yield or the change of product price. Land rent, on average, is 16% within the production costs on the examined farms, which try to choose better and larger lands for rent. Sometimes, farmers can pay higher land rent for the unit of better land, but this is not a general tendency. It is mainly true that they pay the same land rent for the unit, regardless of land quality. Land owners can not interfere in the use of their land within the rental period, and also is a main characteristic of contracts that important particulars are not spelled out sufficiently by the partners. It follows that their content has to be improved in the future. -
The significance of ecolabels in tourism
118-124Views:86More than one hundred types of ecolabels have been introduced worldwide since the 1980s. These voluntary certifications may play a prominent role in achieving sustainable tourism as, on the one hand, they may encourage companies to behave responsibly, and on the other, they may contribute to increasing tourists’ awareness in their choice. Considering that there are many small and medium-sized companies working on the tourism market, developing voluntary certification systems is highly encouraged in the member states of the European Union.
At the same time, there are significant differences among the various ecolabels concerning their content, qualitative criteria, and requirements, which makes it difficult for them to gain acceptance on the tourism market. It is worth mentioning that the sets of criteria belonging to the ecolabels usually do not involve indicators related to the social and cultural impacts of tourism.
In my paper I review the main characteristics of voluntary certifications with special emphasis on the players in tourism ecolabels, furthermore I discuss their advantages and some of the arising problems as well. -
Analysis of vitamin E content in pilot dairy products
31-34Views:116Within the framework of Ányos Jedlik program we started an experiment on feeding anti-oxidants with dairy cows at Körös-Maros Biofarm Kft. The purpose of the experiment was to test whether vitamin E and selenium fed as feed-supplement have an effect on the composition of milk produced. Furthermore we examined the cheese and yoghurt made out of the milk to explore how much vitamin E and selenium is retained in the products after processing. Our goal is to develop such functional dairy product which can be part of the daily diet helping us to remain healthy.
After analyzing the data we found out that the anti-oxidant fed to the cows resulted in elevated vitamin E and selenium levels in the milk and that these were retained in the cheese and yoghurt in relatively large amount. -
The role and impact of N-Lock (N-stabilizer) to the utilization of N in the main arable crops
51-55Views:215The nitrogen stabilizer called N-Lock can be used primarily with solid and liquid urea, UAN and other liquid nitrogen, slurry and manure. In corn it can be applied incorporated before sowing or with row-cultivator or applied with postemergent timing in tank-mix. In postemergent timing need precipitation for long effect. In oil seed rape and autumn cereals the N-Lock should be applied with liquid nitrogen in tank mix late winter or early spring (February-March). The dose rate is 2.5 l/ha. N-Lock increases the yield of maize, winter oil seed rape, winter wheat and winter barley 5-20 %. The yield increasing can be given the thousand grain weight. In case of high doses of nitrogen it can be observed higher yield. The quality parameter also improved, especially the oil content of winter oil seed rape and protein and gluten contents of winter wheat. The use of N-Lock increases the nitrogen retention of soil and reduces nitrate leaching towards the groundwater and the greenhouse effect gas emissions into the atmosphere. The degradation of the applied nitrogen is slowing down and the plant can uptake more nitrogen in long period. The effect of N-Lock the nitrogen is located in the upper soil layer of 0-30 cm and increasing the ammonium nitrogen form. The product can be mixed with herbicide products in main arable crops.
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The effect of NPK fertilization and the number of plants on the yield of maize hybrids with different genetic base in half-industrial experiment
103-108Views:178In our research we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize.
The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2, this it was a halfindustrial experiment. We tested six hybrids with different genetic characteristics and growing seasons. I analysed the correlation between the nutrient supply and the yield of maize hybrids with control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. Yield increasing effect of the fertilizer also depended on the number of plants per hectare at a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants/ha.
In Hajdúszoboszló, in 2015 the amount of rainfall from January to October was 340.3 mm, which was less than the average of 30 years by 105.5 mm. This year was not only draughty but it was also extremely hot, as the average temperature was higher by 1.7 °C than the average of 30 years. In the critical months of the growing season the distribution of precipitation was unfavourable for maize: in June the amount of rainfall was less by 31mm and in July by 42 mm than the average of many years.
Unfavourable effects of the weather of year 2015 were reflected also by our experimental data. The yield of hybrids without fertilization changed between 5.28–7.13 t ha-1 depending on the number of plants.
It can be associated also with the unfavourable crop year that the yield of the six tested hybrids is 6.33 t ha-1 in the average of the stand density of 60, 70 and 80 thousand plants per hectare without fertilization, while it is 7.14 t ha-1 with N80+PK fertilizer treatment. That increase in the yield is only 0.81 t ha-1, but it is significant. Due to the especially draughty weather the yield increasing effect of fertilizers was moderate. In the average of the hybrids and the number of plants, increasing the N80+PK treatment to N160+PK, the yield did not increase but decreased, which is explicable by the water scarcity in the period of flowering, fertilization and grain filling.
The agroecological optimum of fertilization was N 80, P2O5 60 and K2O 70 kg ha-1. Due to the intense water scarcity, increased fertilization caused decrease in the yield. As for the number of plants, 70 000 plants ha-1 proved to be the optimum, and the further increase of the number of plants caused decrease in the yield.
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Leaf and root evaluation of bioactive compounds of different beetroot varieties
135-139Views:195The importance of beetroot lies in the numerous health benefits, attributed to its wide-ranging array of minerals, vitamins and bioactive compounds which play a key role in the human diet. Generally, beetroot is consumed for its root, however, its leaves also contain a good amount of bioactive compounds. The experiment was carried out with four beetroot varieties in order to compare the amount of bioactive compounds in the root and the leaf. The analyzed data were total dry matter content, total polyphenol, flavonoid and vitamin C.Results have shown that roots contain the highest amount of bioactive compounds. Nevertheless, leaves can be also considered a significant source. Therefore, consumption of the young leaves is highly recommended due to their availability after thinning or at maturity stage (60 days after the germination). Of the examined varieties, ‘Libero’ demonstrated the highest total polyphenol, flavonoid and vitamin C values, although it was found to be statistically insignificant. -
Genetic Diversity of Hair Colour in Horses
40-45Views:76The main aim of this study was to analyze sources of variability for coat colour expressed as a quantitative trait as well as to determine non genetic factors influencing horse colour variation and shades. Traditional Hungarian horse breeds such as Lipizzan (grey), Gidran (chestnut), Shagya Arabian and Arabian Pure Bred (grey) and Nonius (bay and black) horses were involved in the current study. We report results using direct measurements of horse coat colour using objective colorimetric dimensions and a spectrophotometer for determining hair melanin. Correlation analysis indicated that the single biological component that correlated best with the total melanin content of horse hair is the L* value (r=-0.858, p<0.0001). Subjective colour classes and coat colour variables L* and a* were obviously related, with R2 values of 0.88 and 0.46 respectively, with a lower R2 for b* of 0.22 (all p<0.001).
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The noise monitoring system of Debrecen International Airport and requirement of appointing noise protection zones, regarding to the growing air traffic
191-194Views:107The Debrecen International Airport has been undergoing a significant transformation regarding to the growth of traffic and its composition. Considering the dwelling zone location of the airport we cannot avoid the possible noise pollution that it may cause, since its permanency, and growth of intensity, could be the reason of durable health deficiency. The airports’ noise pollution zones are determined, and classified by domestic, and international regulations, the measured data of the noise monitoring system, and the content of the air traffic regarding to the type of planes. Summoning all of these we recommend the D zone qualification of the airport, and the traffic daylight restriction referring to the S5 type of planes. We also advise to build up a more sophisticated and wider extended noise monitoring system.
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Contributions to the 2014 and 2015 flight pattern and damages of Carpomyia schineri Loew.
96-99Views:126The fly Carpomyia schineri Loew is a pest of the berries of the feral Rosa canina group but is can also be found in the berries of grown rose cultivars. The larva damages the flesh of the berry, several larvae can develop inside a single berry. It can decrease the quantity and ascorbic acid content of the tea and jam, which are important human ascorbic acid sources during winter. At the same time in trapping experiments the adult can be confounded with adults of the walnut husk fly (Rhagoletis completa Cresson). In collections of berries at several sites in Hungary damage levels ranged from 0.88% to 65.08 %. Based on these damage levels we had the impression that the yellow sticky traps CSALOMON® PALz or PALs baited with the synthetic Rhagoletis lure caught moderate numbers of adults and were not satisfactory for detection, consequently improving trapping methods is necessary in the future.
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Usage of different remote sensing data in land use and vegetation monitoring
7-12Views:114The use of remote sensing in forest management and agriculture is becoming more prominent. The rapid development of technology allowed the emergence of database suitable for precision application in addition to the previously used low-resolution and low data content images. The high resolution, hyperspectral images are not only suitable for separating the different land use categories and vegetation types but also for examining the soil characteristics and biophysical features of plants (Blackburn and Steel, 1999; Condit, 1970). We processed a multispectral satellite image (Landsat 7 ETM+) and a hypespectral areal image (DAIS 7915) about a farm on the plains and evaluated the different image classification methods. During our examinations, we examined the geometrical and radiometrical characteristics of images first, then assigning the training areas, we determined the spectral characteristics of land use categories. We performed a multispectral analysis for checking land use, where we compared controlled and uncontrolled classification systems to check their reliability. We used areal and spectral reductions to make the classifications more accurate and to reduce the length of calculations.
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Evaluation of sweet sorghum and sudangrass varieties by the viewpoint of bioethanol production
57-61Views:122Bioenergy and biofuels are very important in today’s energy policy. These kinds of energy resources have several advantages against fossil fuels. Environmental protection is a cardinal point of widespreading these technologies but the economic considerations are important as well. In order to improve the rate of the renewable energy in the energy consumption, the European Union settled down a program which determines a minimum ratio of renewable energy in the energy consumption for each member country of the EU. To fulfil the requirements bioenergy and biofuels should be produced. This production procedure needs adequate stocks which are commonly agricultural products.
One of the promising stocks is sorghum. This plant fits for bioethanol production due to its juice content being rich in sugar. In this study six sweet sorghum hybrids, two sudangrass hybrids and a sudangrass variety have been evaluated to determine their theorical ethanol production capacity.
On the score of the results of the year 2009 it can be set that sudangrasses have a lower theorical ethanol capacity than sweet sorghums have. In the case of sweet sorghums 1860.29–2615.47 l ha-1 ethanol yields had been calculated, while the sudangrasses had only 622.96–801.03 l ha-1. After that throughout three years (2011–2013) the sweet sorghum hybrids have been evaluated in order to determine the fluctuations of the ethanol production capacity caused by the impact of the years. As a result 2425.44–4043.6 l ha-1 theorical ethanol capacities have been calculated, which means that sweet sorghums can be an adequate stock to produce bioethanol. -
Evaluation some important microbiological parameters of the carbon cycle in chernozem soils profiles
33-39Views:154Some chemical and microbiological properties of the carbon cycle were investigated in three chernozem soil profiles. The soil profiles originated from a long term fertilization experiment (potato) of the University of Debrecen, Látókép, Kryvyi Rig Botanic Garden (grassland) and a large-scale farm (sunflower) of Ukraine. The results of the organic C-content, total number of bacteria, microscopical fungi, cellulose decomposing bacteria, CO2-production, microbial biomass carbon and saccharase and dehydrogenase activities were compared and evaluated with the help of correlation analyses. Close correlation was found between the organic carbon content and the number of microscopical fungi,, saccharase and dehydrogenase enzymes’ activities, as well as close correlation was found between the dehydrogenase activity and microbial biomass-C and saccharase activity.
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Essential oil extraction from herbs and their use in the food industry
59-74Views:347Essential oil extraction of wild caraway and thyme was performed using a classical (HD) and microwave hydro-distillation (MWHD) and a laboratory supercritical fluid extraction (SFE) with a carbon dioxide as solvent. Our experiments demonstrated that the extraction yield of the essential oil performed in same conditions was influenced by the location of growth area; the maximum extraction yield of 10 ml 100 g-1 caraway was obtained from dried seeds collected from Csíkmadaras. This quantity far exceeded the yield of the Újtusnád samples. In the case of wild caraway (Carum carvi L.), the extraction method influenced thecomposition of the essential oil (carvone/limonene ratio), the highest limonene content being achieved by classical hydro-distillation. In the case of thyme, this effect was not detected, the thymol/carvacrol ratio was independent from the given extraction method. The obtained thyme essential oil possesses high antimicrobial activity demonstrated by agar diffusion test. The thyme extract provides a good protection against microorganisms collected on the surface of fresh vegetables following bacterial stains: Citrobacter portucalensis, Pseudomonas hunanensis, Pseudomonas baetica, Pseudomonas parafulva, Bacillus mojavensis and Enterobacter cloacae. Protective effect was also detected on the vegetable surface of by chitosan-based edible film coating during a 6-day-long storage period at a temperature of 4 °C. The caraway essential oil used as soft cheese seasoning with a direct, dilution-free method, proved to be unsuitable because the uneven distribution and confer a strong, unpleasant taste to the product in comparison with the ground wild caraway seed-dressed cheese.
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The effects of curing technology on the rheological and organoleptic features of meat products
139-142Views:80Meat products are important staple foodstuffs owing to their high protein, vitamin and mineral content. Meat plants do not only use traditional production technologies but also develop methods that preserve the nutritional value of meat or improve the texture and organoleptic features of meat products. These features play an important role in the consumer society. Consumers first meet the external features of meat and this experience influences their decisions. Our analyses compared a traditional and a new curing procedure. Besides organoleptic inspections, we analysed texture with a CT3 type Texture Analyser to obtain quantified information on the condition of meat samples in the various curing phases. We used our results to compare traditional and new curing procedures.
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Preliminary results of the combined production of duckweed Spirodela polyrhiza and common carp (Cyprinus carpio) in an aquaponic system
83-89Views:66As a result of population growth, increasin amount of food is needed, and agriculture is under an increasing burden to meet these needs. Traditional agriculture is often attacked due to its environmental impact. We must find alternative, environmentally friendly ways to produce more food. Aquaponics is a closed system in which we can produce both fish and plants at the same time. Duckweed species are small, aquatic, floating plants belonging to angiosperms. It can potentially be an alternative protein source, due to its high protein content, good amino acid supply, and rapid growth. Under suitable conditions, it doubles its weight in 2–4 days, and can reach a yield of 30 t ha-1 year-1in dry matter. It forms a carpet on top of the water and can be found in slow-moving or still waters. Since they are resistant to a wide range of nutrient concentrations, they are also suitable for cleaning wastewater (such as eutrophicated lakes, sewage reservoirs, liquid manure storage). Fish feed is the primary nutrient source for aquaponic systems, which usually contains fishmeal. If duckweed can be used as an alternative for fishmeal in the feed, it could improve the sustainability of the aquaponic and aquaculture systems. In this study, the aim was to develop an optimal harvesting protocol for duckweed Spirodela polyrhiza under aquaponic conditions. In a four weeks experiments, four harvesting protocols were set up, a control where only biomass measurements were made, a 25% group where 25% of the biomass at the time of measurement was harvested, and a 50% and a 75% group where at the time of measurement 50% and 75% of the biomass was harvested. Three replicates were used per treatment. We weighed the biomass every week and removed the amount corresponding to the group. Based on the preliminary results, it can be said that more biomass was obtained in the groups with the 25% harvesting protocol and the control group.
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Determining elements of variety-specific maize production technology
157-161Views:62Our aim was to work out such new maize fertilizer methods and models which can reduce the harmful effects of fertilization, can
maintain the soil fertility and can moderate the yield fluctuation (nowadays 50-60 %).
The soil of our experimental projects was meadow soil. The soil could be characterized by high clay content and pour phosphorus and
medium potassium contents. In the last decade, out of ten years six years were dry and hot in our region. So the importance of crop-rotation
is increasing and we have to strive for using the appropriate crop rotation.
The yields of maize in monoculture crop rotation decreased by 1-3 t ha-1 in each dry year during the experiment (1983, 1990, 1992,
1993, 1994, 1995, 1998, 2000, 2003, and 2007). The most favourable forecrop of maize was wheat, medium was the biculture crop rotation
and the worst crop rotation was the monoculture.
There is a strong correlation between the sowing time and the yield of maize hybrids, but this interactive effect can be modified by the
amount and distribution of precipitation in the vegetation period. At the early sowing time, the grain moistures were 5-12 % lower compared
to the late sowing time and 4-5 % lower compared to the optimum sowing treatment.
There are great differences among the plant density of different maize hybrids. There are hybrids sensitive to higher plant density and
there are hybrids with wide and narrow optimum plant densities.
The agro-ecological optimum fertilizer dosage of hybrids with a longer season (FAO 400-500) was N 30-40 kg ha-1 higher in favourable
years as compared to early hybrids.
We can summarize our results by saying that we have to use hybrid-specific technologies in maize production. In the future, we have to
increase the level of inputs and have to apply the best appropriate hybrids and with respect to the agroecologial conditions, we can better
utilize the genetic yield potential. -
Influence of Foliar Treatments on the yield and quality of Sugar Beet
119-123Views:80The yield and quality of the sugar beet are mainly determined by the plant production system, thus we studied the effect of mineral fertilization. Our field trials were carried out in 2005 in Hajdúböszörmény, at two sites. We studied the effect of sulphur (Cosavet DF), copper (Kelcare Cu) and two foliar nutrients with high active agents. Treatments were replicated four times.
We took root samples at 4 week intervals, starting in August. The quality of root (sucrose, potassium, sodium and alfa-amino N content) was determined from filtrated beet broth, by an automatic beet laboratory system, called VENEMA.
We found that the crop and the sugar yield were significantly influenced by the foliar treatments