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  • Physiological plasticity of main tree species of lowland hornbeamoak forest as a results of forest gap regeneration
    99-103
    Views:
    441

    Specific leaf area (SLA) of English oak (Quercus robur L.) and hornbeam (Carpinus betulus L.) as members of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the inert forest. The artificial opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important ways for plant life and plant production basically influenced by altered light condition resulted in opening process. Efficient photosynthesis is important for plant life, plant production, but species-dependent plasticity of photosynthesis makes one species more tolerant, than others. The specific leaf area is acceptable parameters for characterising plant production, dry matter content and leaf structure. The dry matter content based on known leaf area is higher in oak both sun and shade leaves, than hornbeam. The different place of leaves in the canopy of trees did not influence the values of SLA.

  • Effect of sufficient and deficit irrigation with different salt inputs on the yield of cucumber
    19-25
    Views:
    326

    Soil salinisation is considered one of the major environmental hazards threatening agricultural productivity and can be accentuated by climate change as well as the use of low-quality water in irrigation. This is the case in our study area which is affected by secondary salinisation due to the use of saline irrigation water for horticultural production. Deficit irrigation technique is implemented especially in arid and semiarid regions due to its potential to optimise water productivity while maintaining or increasing crop yield. The main objective of this study was to compare the effect of irrigation with sufficient (SD) and deficit (DD) doses. This research was carried out in Karcag in 2020. Cucumber was grown on a meadow chernozem soil and was irrigated with SD and DD of two irrigation water qualities. Soil moisture was monitored and crop yields were recorded. Despite the differences in quality and quantity of water, the application of less water by DD maintained the same yield as SD. We found a non-significant difference between the average soil moisture contents under the treatments (15.5 v/v% for SD and 13.5 v/v% for DD). Deficit irrigation can be an efficient technique due to its potential for improving water use efficiency, maintaining sufficient soil moisture content favourable for proper crop development and yield.

  • From Lovrin to Szécsény – remembrance to Béla Lipthay (1892-1974)
    21-32
    Views:
    249

    Béla Lipthay lepidopterologist, entomologist, museologist, agriculturist, hussar lieutenant, life-saving Roman Catholic, descendant of the historical family Lipthay de Kisfalud et Lubelle did a long way from his home village Lovrin to Szécsény, the one-time land of his ancestors. His life coincided with the disintegration of the historical Hungary, and the most serious trials of the Hungarian society, culture and spirit. These changes affected him as a member of Hungarian aristocracy many times and in fact wanted to destroy him. The fortune of the ancestors have been swept away by the storms of the wars, confiscated by the beneficiaries of tricky ideas of the new age and decimated by practical swindlers, but the human strength of character, the consciousness, the advantage of education and the with them associated ability, diligence, inventiveness and the sanctuary of faith have remained. All these made him possible to survive, to do his everyday hard creative work, which gained him the affection, the esteem and respect of the people living around him.
    Protecting his remembrance we evoke his many-sided, altruistic efforts for the Hungarian people and Hungary, and we can contribute to the creation of a better and just world.

  • Use of molecular marker methods in the classification of bamboo taxa: A review
    51-59
    Views:
    474

    Bamboo plants are currently attractive to researchers because of their versatile uses. Understanding the bamboos’ genetic level is needed to develop new varieties. Taxonomic identification is the basis for plant development. Bamboos were identified as their taxonomical morphological characters which are dependent on environmental factors. Molecular Marker techniques can be used to perform accurate genotype identification, which can be used for genetic diversity analyses. The RFLP, RAPD, AFLP, SSR, ISSR, iPBS, SCARS, SCoT, SRAP marker systems have been shown to be able to efficiently determine the genetic diversity of bamboo species based on genotyping. This paper summarizes research that aims to analyze the genetic diversity of bamboo species on a molecular basis.

  • Organic soybean production in Hungary
    45-52
    Views:
    476

    Organic soy production, particularly for feedstuff in organic animal husbandry, is needed in Hungary and the EU regions. Soybean producing crop area in Hungary has increased in the last years, however, the agroecological potential would allow for a larger soybean production area. This study presents the soybean market in Hungary, and the role of soybeans in protein supply in food and feed, summarising the critical elements of organic soybean production from variety selection to marketing. During the field research, the effects of the agronomical environment on yield potential factors were examined. We aimed to determine how different row spacing and tillage systems affect organic soybean yields of different varieties, with particular attention to the dry region, and determine the specific methods and varieties of soybean that favour these areas. We found that the tillage (plough/grubber), the spacing (wide/narrow), and the variety effects were all significant on morphological variables. The most remarkable difference was seen in plant height and the number of pods per plant, while the number of nodes was also highly impacted by tillage treatment and variety. The nutrition variables were significantly different, mainly as an effect of tillage and spacing interaction with significantly different plant responses of varieties.

  • Renewable energy strategy in Hungary
    101-104
    Views:
    273

    The price of energy determinates our daily life. It is very necessary that we make energy strategy such as effective in everyday life, furthermore appoint a predictable development path. In these energy strategies the renewable energy and the energy efficiency is highlighted. This article describes about relevant pledges from recent years and possible improvements.

  • Influence of temperature and variety on seed germination of soybean (Glycine max L. Merr) at different germination times
    5-12
    Views:
    427

    Seed germination is an important stage in crop development that affects plant performance, crop yield, and quality. Many factors influence seed germination, and one of the most important factors is temperature. The closer the temperature is to the optimum, the faster germination will occur. Temperature affects seed germination in various plants and varies depending on the variety. Therefore, the effect of temperature on seed germination is necessary to investigate, also for soybean varieties. Soybean is one of the world's most valuable oil-seed crops. Generally, proper seedling establishment and germination of soybean seeds are crucial processes in the survival and growth cycle of the crop. Thus, a study was done to investigate the influence of temperature and variety on soybean seed germination at different times after sowing. The experiment was carried out at the Institute of Agronomy, Hungarian University of Agriculture and Life Sciences (MATE), Crop Production Laboratory. Seeds of two soybean varieties were subjected to three different temperatures: 15, 25, and 35 °C, and two soybean varieties, Martina and Johanna were tested. There were four germination times based on the days after sowing: Days 3, 5, 7, and 9. This experiment was set up with a completely randomized block design and four replications. According to the findings of this study, the Martina variety showed a better germination rate as well as higher vigor and viability than the Johanna variety in the first 12 days after sowing. At temperatures of 15 °C and 25 °C, both varieties achieved comparable percentages of viability, but they were more vigorous at 25 °C due to better total seedling length. Thus, the information gained from this study will indirectly determine and confirm the proper temperature for the initial growth of the Martina and Johanna varieties.

  • Remembrance of Bognár Sándor (1921-2011)
    16-20
    Views:
    260

    Dr. Sándor Bognár was a distinguished cultivator of the horticultural entomology and a determining personality of the higher education of Hungarian crop protection. Training of the scientific and extension specialists of Hungarian agricultural entomology would have been unimaginable without him. He was researcher of the Plant Protection Institute, innovator of the crop protection training’s essential and organisational standard at the Horticultural College and Faculty, who sacrificed his life’s work for developing the crop protection and for the tracking of the history of Hungarian crop protection. He dealt with the Pimplinae (Ichneuminidae) at the very beginning of his carrier and later with the difficulties of soil dwelling pests (Elateridae) but he dedicated a lot of time to the pests of rice and the pest-assemblages of fruit trees and grape. It is important to mention his activity on the phytophagous mites, thus one can call him as one of the founders of the Hungarian agricultural acarology. One top of his educational work was the wonderful manual „Agricultural Entomology” written with László Huzián in 1974 and 1979. László Szalay-Marzsó said of this book that it was impossible to write a better one. He has been right. In spite of his advanced age he participated systematically in the conferences in Hungary and shared the knowledge gained during his long life, and the morals and patriotism got from his models and developed considerably.

  • Supplementary botanical examinations for modelling the grass production of the great pasture of Hajdúbagos
    17-21
    Views:
    201

    Our botanical survey at the great pasture of Hajdúbagos is a part of a broad research that aims to predict the production of the grass at the given area. As the mentioned pasture is a nature conservation area, the usage of artificial fertilizers or other classic grassland management methods in its handling are prohibited. Thus grazing is an important tool for the management of this area, however the not suitably regulated grazing order and the poorly calculated carrying capacity cause serious problems at some parts of the pasture. The prediction of the grass yield is essential to
    avoid both over- and both under-grazing and for determining the optimal number of the grazing animal stock and the grazing method, thus the most suitable management strategy.
    The potential grass yield is easily calculable with a computer model that will be established as a basis for determining the grass production. For the sake of getting an accurate view of the plant associations of the pasture, we created examination quadrates and determined all plant species found in the quadrates. After plant determination, we compiled a coenological table in which we marked besides the scientific name and families, the life forms of each species that refer to the structure, morphology and thus the adaptability of plants to their environment. We determined the
    TWR, so the thermoclimate, water and soil reaction values, the nature conservation values, as well as the covering values of each plant species (DB), and the total coverage of the examination quadrates (B%).
    According to the covering values, grasses proved to be characteristic plants at the examined pasture, thus we need to consider them influential in calculating the animal carrying capacity and with the rest of the information, we need to supply the model.
    The life forms and TWR indicators, all together with the nature conservation values provide further important data to the development of the management suggestion of the protected pasture. By examining these values to different parts of the area, we could get an exact view on the measure of the degradation effects. This promotes the determination of grazing methods and the forming of the boundaries of certain pasture sections, to avoid  those harmful anthropogenic effects that seriously endanger this extensive sandy pasture. 

  • Environmental inspection agro tech – guarantee sustainable development agricultural systems
    41-42
    Views:
    236

    Shown the expediency of the environmental expertise technologies of growing crops in terms of impact on soil fertility, crop phytosanitary status, quality, chemicals migration, biological soil activity, crop productivity, which ensure avoidance of adverse impact on the environment and human health.

  • The supply of Liget-Thermal Spa and Experience Bath, according the opinion of the guests
    199-205
    Views:
    194

    During the last decades health, body and soul control became important issues. In the modern world this values are closely connected to the term of success, because we can be successful in every aspect of life: work, and personal life, if we can maintain our health, and fitness in a long run. From that comes that modern people are willing to spend money and time to take an active part in sporty but relaxing activities in a healthy environment in order to keep their fitness or just feel themselves well.
    In my study I will show the main motivating factors and demand elements of wellness and healthtourism, according the opinions of the visitors of Liget - Thermal Spa and Experience Bath. I will introduce different services that are suitable for satisfying this demand, furthermore we can get an insight by the results of questionnaire survey, how the motivating factors and the demand changes in case of different age groups.

  • Development of the reproductive tract of immature gilts
    165-166
    Views:
    173

    Mechanisms of regulation of litter size in pigs are complex and depend on many factors, including genetic regulation and also physiological and anatomical development of the reproductive tract in gilts. Improvement of growth rate in present breed pigs raises the question as to whether, with the development of the reproductive tract, sexual maturity would also be attained.
    The aim of the study was to assess the morphometric traits of reproductive tracts taken from gilts slaughtered at 100 kg body weight, i. e., just when they may become actively sexual mature.
    This study was concluded on 80 prepubertal gilts of the Polish Landrace (PL) breed tested at the Pig Program Testing Station. The animals were kept in individual pens with control feeding and standard management. They were slaughtered after attaining 100 kg body weight. Immediately after slaughter, the reproductive tract was removed and carefully assessed. The morphometric estimation of the reproductive tract involved the
    measurement of uterus weight with ligament, vagina-cervix length, uterine horns and oviducts length, ovaries weight, height and width. Uterus volume capacity was also determined, based on volumetric method of Kwaśnicki’s (1951) with own modification.
    All pigs were divided into three groups in respect to age at slaughter: A – below 160 days (n=38), B – from 160 to 180 days (n=28) and C – above 180 days of age (n=14). The results were elaborated statistically computing the arithmetic means (x) for every traits and standard deviations (s). One-way analysis of variance ANOVA was performed. The significance of differences between age groups was estimated using Duncan’s test.
    Calculations were performed with STATISTICA 8PL Software.
    Obtained results are presented in the tables below. The most pronounced differences in the development of the reproductive tract are dependent on the age of gilts concerning only the uterus weight (P≤0.01) and uterus vagina-cervix length (P≤0.05). Gilts at age 160-180 days attained the full stage of reproductive tract development. Differences between the compared age groups of gilts dealing with the other morphometric traits
    and ovary characteristics were statistically not significant.

  • A review on fish in vitro digestion studies
    55-63
    Views:
    158

     (1) Background: In vitro experiments in fish have been developed to search for dietary substitutes of fish meal in aquafeeds by measuring the digestibility of various feedstuffs by simply simulating the conditions of the stomach or portions of the digestive tract. In vitro digestion studies involving mainly commercial fish species have been conducted to determine the digestibility of conventional and alternative ingredients in fish diets using diverse digestion models. However, there remains a significant knowledge gap, particularly regarding the enzyme functionality, digestion mechanisms in many fish species, and the factors influencing enzymatic activity. This review article is focused on the importance of the use of different enzyme sources in the in vitro digestion model to predict protein hydrolysis.;(2) Methods: For this review, a comprehensive analysis of articles was conducted to gain insights into diverse enzyme interactions and feed evaluation assessments, from the nutritional science and biotechnology sector.; (3) Results: A total of 36 peer-review papers, which include original, and review articles were selected.; (4) Conclusions: In vitro digestion studies offer a valuable tool for evaluating the digestibility of conventional and alternative feed ingredients, helping to identify sustainable dietary substitutes for fish meal while reducing dependence on live animal trials.

  • Dilemma of interpreting the Tisza space in regional dimensions
    169-171
    Views:
    226

    This study deals with the evaluation of an especially important area, since the Tisza river is the basis of the spatial organisation of the Great Plain, the main spatial structural axis of Eastern Hungary and also its ecologic corridor of continental significance. The Tisza is a river which connects five countries to each other and it has an enormous catchment area. Its longest section can be found in Hungary. Two million people live directly in the spatial environment of the river. The safety and favourable quality of life of these people have to be provided. This is a great challenge from the aspect of regional development, economic, technological improvement, the acceleration of innovation processes, as well as the establishment of natural and environmental harmony.

  • Examination for Susceptibility of CAE
    33-36
    Views:
    435

    Caprine Arthritis Encephalitis (CAE) is a group of diseases in goats caused by a retrovirus, namely the Caprine Arthritis Encephalitis Virus. CAEV belongs to the lentivirus group within the retrovirus family. The CAEV is intimately associated with white blood cells, therfore any body secretions which contain white blood cells are a potential source of virus to other goats in the flock. Once goats are infected with CAEV, it remains infected for life and has to be eliminated.
    Since not all goats infected with CAEV progress to disease, very important to test goats for infection using a serology test (ELISA, AGID, IDT). These serological tests demonstrate the presence of antibodies to CAEV in goat serum or detect the virus genome in the white blood cells. However, Swiss results (Dolf and Ruff, 1994) pointed out individual and species differencies in predisposition for this disease. This result was considered as a starting point to our examination. Microsatellite analysis was used in order to find whether there was any association between genotype and serological results, and to look for a marker associated with this disease. To date, altogether 135 goats have been examined. Unfortunately, a significant association between serological results and genotype was not found using the Chi2 test

  • The economic structure and the tertiary ecucation of the function of transformation Hungary 19th and 20th century of in economic integration periods
    115-122
    Views:
    225

    Knowledge-intensive businesses sectoral nature of the operation and the specific attributes of the innovation life cycle processes, different needs and different needs induce. These features can also differentiate time that their activities when and what type of resources they require. The availability of capacity in terms of a network co-benefits for those businesses that are creating the possibility that such resources are available to ensure the realization of goals that are not individually owned. These factors and the availability of local availability is also motivated by the small and medium enterprises willingness to cooperate.

    Regional supply of resources necessary for the operation of the business of insurance, universities play a key role. The functions of universities in innovation as a business service can be understood as an activity that mediate high added value to other organizations and companies. Questions arise as to the innovative nature of the business industry and sector weights would differentiate whether the R&D&Iintensive areas of expertise.

  • The examination of human resources in the Hódmezővásárhely micro-region on the basis of human resource hierarchy
    91-110
    Views:
    184

    In this paper, I deal with the examination of the situation and change of human resources through the human resource hierarchy. My research covers the Hódmezővásárhely micro-region, which includes four settlements, two towns (Hódmezővásárhely as the centre of the area and Mindszent) and two villages (Mártély and Székkutas). Based on population density the micro-region is qualified as a rural territory, which is underpinned by the micro-region’s market town and homestead like character.
    I took the human resource system of Cloke and Park (1985) published in their book of Rural Resource Management as a basis of my examination and I pursued my research in consideration of Fehér’s (2005) researches related to rural economy. The system of human resources provided a hierarchical and logical framework for my examination. In the course of the research I made analyses along the three levels of human resources concerning the micro-region and its settlements.
    During the examination of the human resources of the Hódmezővásárhely micro-region I pointed out some negative changes and situations which unfavourably influence the socio-economic processes of the territory and its settlements. All this reveal that the human resources are not only factors of the economy of the micro-region as a rural economy but at the same time they are areas to be developed. The living standard (welfare) of the people living in the area and their quality of life (well-being) depend on the development and level of the different dimensions of the human resources largely. For that very reason there is a need for coordinated development of the human resources and the related fields with respect to the cause-effect relations.
    My research contributes to the better cognition of rural resources of the Hódmezővásárhely micro-region, without this a rational improvement and sustainable development of the micro-region and its settlements based on inner resources cannot be imagined.

  • Utilization of live feeds in fish larviculture: A review
    103-116
    Views:
    642

    This review examines the significance of live feeds in commercial aquaculture industry for production of fish and shrimp larvae, along with various challenges and prospects. Live feeds are an essential food source in larviculture, especially for marine fish, which depend on them for nutrition during the initial days of exogenous feeding. They are palatable, highly digestible, and their movement stimulates natural hunting and foraging instincts, promoting better development, lowering captivity stress, and increasing survival rates. Artemia is the most commonly used live feed in larviculture; however, it has low levels of omega-3 HUFA. Copepods are the most nutritionally rich live feed, containing high levels of DHA and EPA. Despite these benefits, they are less frequently used in larviculture due to technical challenges associated with large-scale cultivation at high densities. The use of live feed is labour-intensive and costly. The feeding period for fish larvae can be shortened using a co-feeding strategy. Microalgae rich in DHA have been utilized to enrich live feeds. Further research is needed to determine the most effective approach to significantly reduce the weaning time of fish larvae from live feed. This will lead to gradual and eventual complete replacement of life feed in the near future.

  • Connection Between Leadership and Communication
    248-255
    Views:
    132

    Discussing communicationis not an easy job as it is about one of the most important symptomps of life, which plays an important role in all social humanic processes. Ways and devices of communication, communicational system of society developed – while in constant connection – with daily activity, social relations, bodies and structure of society.
    Communication takes a prominent part in all forms of management. By the help of this article I would like to demonstrate what importance communication has according to literarure and what relationship can be experienced between communication and management. Is D’Aprix statement reliable saying “communication is management or more properly drafted management is communication”?!

  • Remembrance to László Huzián (1923-1996)
    5-11
    Views:
    270

    László Huzián was a determining personality of the higher education of Hungarian crop protection more precisely that of the agricultural entomology. Training of the scientific and extension specialists of Hungarian agricultural entomology from 1960 till 1983 would have been unimaginable without him. He was the builder of the agricultural entomology school established by Gusztáv Adolf Manninger, the developer of the training’s essential and organisational standard, who sacrificed his life’s work for developing the crop protection. He found, characterized many pests (E.g. Scrobipalpa ocellatella, Lixus scabricollis, Tanymecus palliatus, Mesagroicus obscurus) new for the Hungarian fauna and worked out a control technology against them. It is important to mention his activity in creating the forecasting of the big field crop animal pests mainly that of the sugar beet pests. One top of his educational work was the wonderful manual „Agricultural Entomology” written with Sándor Bognár in 1979. László Szalay-Marzsó said of this book that it was impossible to write a better one. He has been right. The magnificent crop protection library and the unique richness and accuracy of the animal demonstration material (slides, pictures, preparates, showcases, etc.) established at the Gödöllő University of Agriculture can be thanked to his extraordinary systematizing mentality and tireless efforts.

  • Structural and concepcional changes related to the University of debrecen and its sport organizations between the period 2000–2013
    133-139
    Views:
    339

    The strategic and conceptional approach to sport has brought substantial changes in the sporting life of University of Debrecen during the period between 2005–2013. The restructualisation process aiming at the development of university sport as well as the measures related to creating a more transparent financing system demonstrates elements of improvement in comparison to the period prior to the Bologna process. The Sport Concept of the university operates the different areas of sport within a transparent, planed and complex structural framework in accordance with the principles outlined in both the National Sports Strategy (2007) and the legal regulations specified by the Sports Law and its modification (2004, 2011). The conceptional changes of sport at the University of Debrecen followed the main objectives and guidelines of the European Commission that lays a great emphasis on issues such as the integration of athletes into higher education allowing maintenance of parallel educational and athletic carriers for athletes.

  • Landscape tools to support the educational use of school grounds
    63-72
    Views:
    196

    Recent years have seen an increasing emphasis on child-friendly concepts in landscape architecture and urban planning, as well as a growing emphasis on school grounds and environmental education, both in terms of pedagogy and landscape design. School grounds provide places for active engagement with the environment, for experiencing what is taught in class, and, are therefore of particular importance for education and for building children's connection with nature. The aim of this research is to develop a set of landscape architecture tools that can be used to promote child-friendly and education-centered design of school grounds. The research collects and organises the different school ground features, drawing on literature research, and the analysis of the Framework Curriculum. The toolkit presented in this paper lists and evaluates each feature according to its function, its relevance to school subjects and the specific knowledge or skills it can help to acquire, its space requirements and feasibility. To conclude, school grounds offer opportunities for teaching almost any subject and can therefore be linked to educational activities in multiple ways. The results of this research are to be developed into design guidelines in order to be used by designers and teachers alike, to help develop school grounds contributing to the well-being and environmental awareness of new generations.

  • Soil – Environment – Sustainability
    331-337
    Views:
    350

    The future and life quality of human society depends primarily on the success of the sustainable use of natural resources: the geological strata–soil–water–biota–near surface atmosphere continuum. Soil is the most significant conditionally renewable natural resource in our Earth’s system, with three unique properties: multifunctionality; fertility/ productivity; resilience. In the case of rational land use and precise soil management soil does not disappear, and its desirable „quality” does not decrease considerably, irreversibly and unavoidably. Its renewal, however, requires continuous care and permanent activities.
    Consequently, the prevention, elimination or moderation of soil degradation processes and extreme hydrological situations (the two main factors limiting desirable soil multifunctionality) with rational land use and soil management are the key factors and priority tasks of sustainable development on each level and in each phase of the decisionmaking process.

  • Identification of the Slovak traditional cheese “Parenica” microflora
    227-239
    Views:
    426

    Numerous studies have demonstrated the higher accuracy, faster time-to-results and lower costs provided by MALDI Biotyper systems compared to classical methods. In this study, the culturable population of total count of bacteria, enterococci, coliforms bacteria, lactic acid bacteria (LAB) and microscopic fungi and yeasts from cow’s dairy products was identified using the MALDI-TOF MS Biotyper. Altogether, 50 samples of the Slovak cheese “Parenica” were examined. Total numbers of bacteria were cultured on Plate count agar at 37 °C for 24–48 h, aerobically; enterococci were cultured on Enterococcus selective agar at 37 °C for 24–48 h, aerobically; coliforms bacteria were cultured on Violet Red Bile lactose agar at 37 °C for 24–48 h, aerobically. The LAB were cultured on MRS (Main Rogosa agar), MSE and APT agar at 30 °C in microaerophilic conditions. The microscopic fungi and yeasts were cultured on Malt extract agar at 25 °C for 5 days, aerobically. Isolated strains (total 669) were subjected to identification by the MALDI-TOF MS. Among total count the identified bacteria mostly were Acinetobacter baumannii, Bacillus cereus, Micrococcus luteus and Staphylococcus warneri. Escherichia coli and Enterobacter cloacae were the most abundant coliform bacteria representatives identified. Coliform bacteria included Citrobacter, Hafnia and Klebsiella. Altogether three genera belonged to the LAB – Lactobacillus, Lactococcus and Leuconostoc were identified with Lactococcus lactis, Lactobacillus plantarum, Lactobacillus coryniformis, L. fructivorans and Leuconostoc mesenteroides were considered as the dominated LAB species in dairy products. Among yeasts, Kluyveromyces lactis, Candida zeylanoides and Yarrowia lipolytica were among the most isolated.

  • Examining the production parameters of European perch (Perca fluviatilis) juveniles under different lighting conditions
    149-153
    Views:
    437

    European perch (Perca fluviatilis) is a native predatory fish in Hungary, and a promising new species of fresh water aquaculture nowadays. The European perch can be characterized by a high stress sensitivity during the intensive rearing, thus the optimization of environmental conditions has significant importance in the early life stages of fish. The aim of our study was to determine whether the light intensity and darkening of the water by humic acid affect the survival and growth performance of European perch juveniles. The experiment lasted for 28 days. Rectangular aquariums were arranged in 3 lines, the test environment consisted of 24 units. The experiment was set up with 10–10 fish per aquarium, total of 240 individuals. The average wet body weight of the fish at the start of the experiment was 1.69 grams. During the experiment, 6 treatments in 4 replicates were set up. In the first row, we set up 305.6±66.0 LUX (L), in the second row 118.0±24.4 LUX (C), and in the third row (D) 17.0±8.6 LUX illumination was set up. In each row the water of four aquariums were darkened by the addition of humic acid (H) (L, LH, C, CH, D, and DH). At the end of the experiment high survival rate was observed in all treatments. Examining the survival rate, the best results were found in the strongly illuminated treatments (L; LH- SR%=100±0.00). The observed mortality was caused by cannibalism. Regarding the individual body weight, the best results were shown by the treatments where the aquariums were illuminated with lower light intensity (C: 4.66±0.33 grams) and the aquarium water was darkened by humic acid (CH: 4.93±0.15 grams). The results of the C and CH groups were significantly better compared to the other treatments, however, they did not differ statistically from each other. The darkening of the water had a positive effect on the individual body weight of fish reared under full light (L: 3.73±0.28 grams; LH: 4.33±0.28 grams), whereas in the case of fish reared in the lowest illumination, the addition of humic acid did not affect the results (D: 3.78±0.15 grams; DH: 3.80±0.26 grams). In case of SGR (C: 3.64%/day and CH: 3.74%/day) and FCR (C: 0.84 g/g and CH: 0.78g/g) the best results were obtained by the C and CH treatments, also.