Search

Published After
Published Before

Search Results

  • Change management at clusters: first results of a change management survey among clusters at European level
    81-85
    Views:
    117

    Change is a natural characteristic of organisations at the end of the twentieth century and in the upcoming ages. The dynamism of the environmental effects and the heterogeneity of the environment urge organisations to continuously adapt to these changes. It means that organisations and clusters which are more or less agglomeration of organizations should be open to external influences and those organisations responding faster are more viable. From the professional literature several change management methods and tools are known. However, few sources deal with clusters. A cluster is also a unique organizational structure: its specialty lies in the fact that even large clusters are built up from smaller organisations in an environment where flexibility, rapid economic decisions and high level buoyancy is needed. The question is whether the general change management methods and approaches can be interpreted regarding clusters.

  • Challenges – the impact of climate change on the nutritional management of Hungarian orchards
    323-334
    Views:
    262

    The agricultural sector is increasingly exposed to both environmental and economic risks due to the phenomena of climate change and climate variability. Fruit growth and productivity are adversely affected by nature’s wrath in the form of various abiotic stress factors. Climate change and extreme climatic events are predicted to increase in intensity, frequency, and geographic extent as a consequence of global climate change. It is no doubt that frequency of unexpected climatic events and their growing rate result in an increasing amount of problems for fruit growers globally. Today, climate change impacts are the most serious problems for Hungarian fruit growers as well. It can be stated that the nutrient demand of fruit trees can be supplied only under even worse conditions.

    Therefore, it is so important to know and apply adaptation and mitigation strategies in horticulture to improve fruit quality and yield. In the last ten years, at the Faculty of Agricultural and Food Sciences and Environmental Management at University of Debrecen expanded studies have been made to prove the importance of groundcover management in horticultural applications. In this mini review paper, is presented, how the university's researches contributed to the expansion of knowledge of preservation of soil moisture and what advice we can provide for fruit growers to face the challenges of climate change.

  • Mitigation and adaptation measures in the hungarian rural development programme
    245-250
    Views:
    82

    In the Hungarian Rural Development Programme (RDP) climate change adaptation is addressed through the measures in Axis 1, 2, 3 and 4. Under Axis 1 farmers can receive support for farm modernisation that will help them adapt to climate change. The processing industry will also be able to use the available resources for capital expenditure on buildings and new equipment. Axis 2 and especially the soil and water package within the agrienvironmental
    measure aim to support production methods, which protect soil quality and will help adaptation to climate change. Measures of Axis 3, such as basic services for the economy and rural population, village renewal and development will provide local communities the opportunity to identify actions that can be undertaken to deal with the effects of climate change. On the other hand, the extension of forest resources contributes to climate change mitigation and enhances carbon sequestration. New methods have been elaborated to the sustainable regional water management, irrigation, water regulation, defence against internal water, and soil protection established. Water management contributes to the balance of water quantity on one side, but also to mitigating the climate change on the other.

  • Study on Human Resource Management in Agriculture
    171-181
    Views:
    93

    The human factor has been reassessed with regard to strategic initiatives towards obtaining and preserving competitive advantage. Knowledge, experience and special skills are a specific form of capital, forming part of the organisations’ assets and serving as an organisational strategic resource. Their development and use require major investments, both on the part of the individual and the organisation. In a Europe undergoing integration, the quality of human resources enjoy priority among our really important values and specific features. The opportunities of the near future can be utilised, and agricultural economic organizations can survive and increase their organizational effectiveness, if they possess a basis of human capital which is able to make a shift in perspective and behaviour which is of primary importance from the point of view of incorporating market mechanisms and implementing them in practice. My investigations were focused on the current position of human resource management in a comprehensive manner; further, on the approach of top managers regarding the future. Analysing the business and other indicators of the companies studied, I have set the objective to describe the differences and special features of the human resource management practice of companies, which are different in size, operational form, and from the perspective of success or failure.
    Human resource management is directed to attracting, retaining, motivating and utilising labour. A given work process can be successful or unsuccessful – given the same conditions – depending on who performs it. Therefore, human resource management related tasks require special attention when enterprises are planned, established and operated. On analysing the responsibilities of human resource management, I have found that the functions and responsibilities of human resource have low or medium importance in the operation of economic organisations today. Regarding the future, top managers have expressed higher expectations of human resource management responsibilities in all areas and they consider individual functions to be more important. The establishment and operation of a human resource information system has been presented as the most important need for change. Correlation analyses have proved that the higher the sales revenues of a company, the higher the development of human resources is regarded by its manager, and the same holds for training, career support and a proper establishment and continuous evaluation of job profiles.

  • Daily soil carbon dioxide flux under different tillage conditions
    141-144
    Views:
    210

    Over the last few years, warming of the atmospheric layer near Earth's surface is increasingly experienced and researchers have also established that concentration of numerous greenhouse gases have risen over the past two centuries value. Change is basically a legitimate process - considering atmospheric concentration as well - but the change experienced during the past centuries could not have become this critical without the contribution of human activity. Due to the nature of the greenhouse effect, the result of a very fragile, complex process is experienced currently on Earth, which can be significantly unbalanced even by a slight change. Carbon dioxide emitted from the soil is involved in the global cycle and has an impact on the greenhouse effect. The rise in soil respiration may result in the further intensification of warming. In the scope of the present study, it was examined how carbon dioxide emissions of the soil evolve over a day. The results have been established based on the comparison of the effects of different parts of the day, tillage methods and irrigation.

  • Change of antioxidant compounds of spices during drying
    77-81
    Views:
    170

    Spices and herbs have been used by humanity for thousands of years, so they are very important plants.

    In this study, the change of dry matter content and antioxidant compounds of eight spices (basil, thyme, rosemary, mint, parsley, lemongrass, chives, coriander) have been examined the raw plants and in plants preserved by three different drying methods (an oven in 50–60°C; drying at room temperature; lyophilisation between -40 and -50°C, under pressure), because we wanted to see the change of the parameters.

    The water content of raw plants was very high, i.e. the dry matter content was very low. By the application of the three drying methods nearly 100% of the water has left the plants, with the exception of the lyophilized basil and rosemary.

    Based on the results related to the original material, lyophilized has proved to be the best treatment for the preservation of antioxidant compounds, however air drying also showed high results for some spices.

     

  • New challenges in soil management
    91-92
    Views:
    227
    Soil management represents two important tasks that are harmonization of the soil protection with demands of the crop to be grown on the given land under prevailing farming condition. Further goals are to preserve and/or develop the soil physical, biological and chemical condition and to avoid the unfavourable changes of the soil biological activity and the soil structure. Classical authors emphasised the importance of creating proper seedbed for plants. In the physical approach, tillage was believed to play an important role in controlling soil processes. Consequently, the period of several centuries dominated by this approach is referred to as the era of crop-oriented tillage (Birkás et al., 2017). The overestimation of the importance of crop requirements resulted in damaging the soils, which inevitably led to turn to the soil-focused tillage. Since the first years of climate change, as the new trends have raised concern, tillage must be turned into a climate-focused effort with the aim of reducing climate-induced stresses through improving soil quality.
    The development of soil management has always been determined by the economical background. At the same time, deteriorating site conditions have contributed to the conception of new tillage trends by forcing producers to find new solutions (e.g. dry farming theory in the past or adaptable tillage theory nowadays). Győrffy (2009) recited the most important keywords were listed in 2001 and that seemed to be important in the future of crop production. These keywords (endeavours) were as follows:
    − Biofarming, organic farming, alternative farming, biodynamic farming, low input sustainable agriculture;
    − Mid-tech farming, sustainable agriculture, soil conservation farming, no till farming, environmentally sound, environmentally friendly, diversity farming;
    − Crop production system, integrated pest management, integrated farming, high-tech farming;
    − Site specific production, site-specific technology, spatial variable technology, satellite farming;
    − Precision farming.
    Győrffy’s prognosis proved to be realistic and the efforts mentioned above have mostly been implemented. New challenges have also appeared in soil management in relation to the last decades. The most important endeavours for the future are:
    1) Preserving climate-induced stresses endangering soils.
    2) Turn to use climate mitigation soil tillage and crop production systems.
    3) Applying soil management methods are adaptable to the different soil moisture content (over dried or wet may be quite common).
    4) Use effectual water conservation tillage.
    5) Use soil condition specific tillage depth and method.
    6) Adapting the water and soil conservation methods in irrigation.
    7) Preserving and improving soil organic matter content by tillage and crop production systems.
    8) Considering that stubble residues are matter for soil protection, humus source and earthworm’ feed.
    9) Site-specific adoption of green manure and cover crops.
    10) Applying site-adopted (precision) fertilization and crop protection. Considering the development in agriculture, new endeavours will occur before long.
  • Climatic water balance in Hamelmalo, Eritrea
    69-76
    Views:
    211

    Agricultural production is an important sector for peoples to live, but it is highly affected by climate change. To have a good production we need to understand the climatic parameters which adversely affect production. Hamelmalo, which is located in the semi-arid area of Eritrea, is vulnerable to climate change and this is realised in the total production loss. Nevertheless, there is no concrete reference about the climate of the region due to lack of data for a long time. Changes in precipitation (P), evapotranspiration (ET) and, implicitly, in the climatic water balance (CWB), are imminent effects of climate change. However, changes in the CWB, as a response to changes in P and ET, have not yet been analysed thoroughly enough in many parts of the world, including Eritrea. This study also explores the changes of the CWB in the Hamelmalo region, based on a wide range of climatic data (P, relative air humidity and evaporation pan necessary for computing potential evapotranspiration (PET) with the pan evaporation method) recorded at Hamelmalo from 2015-2019. This analysis shows that the annual cumulative CWB for Hamelmalo is negative in 67% of the years. The dry season without precipitation leads to negative CWB and the change in CWB only starts from the raining or crop season. Based on this recent study, 2015 had the highest PET and lowest P, and this resulted in the lowest CWB in the investigated period. Opposite to this, 2019 had lower PET and highest P, which led to the highest CWB. However, the monthly values of CWB did not correlate with the annual P or ET. On the base of our study, it can be concluded that PET and P were very variable in the investigated years and P was the most influential elements of CWB.

  • Parameter optimization of an inductively coupled plasma mass spectrometer for measuring arsenic and selenium
    81-85
    Views:
    185

    In 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. 

  • The launch on the way to development or the „revival”... (Comparisons of theoretical and practical approaches apropos of the change and crisis management process of smes and mature companies) .
    65-70
    Views:
    82

    Hungarian SMEs, just like those in other EU member states, often cease for various reasons. Among these factors are many, which should not necessarily turn out this way. These factors are studied in numerous countries while the attempt is also made to create the systems of conditions for these enterprises to recover – often through various aids and supports (from public supports to non-governmental initiatives). Among other things they are trying
    to organize those services with the help of which – if there is the slightest hope for survival – those SMEs in trouble or having serious difficulties could avoid going down by recovering from
    their problematic situation and getting improvements.
    These days this issue comes up more and more urgently in Hungary, as well. It has quite a few signs indicating that – among other things – the reports, the enquiries and commissions of the
    National Association of Change and Crisis Managers (VOE), all of which – just like "thermometers" – reflect this tendency well. 
    I have been doing research on this topic since 1993. As an expert I utilize them, and as a VOE member, vice president, then president I process the relevant Hungarian but mainly French
    experience on the subject. I intend to present those few theoretical and practical results and applicable experience I have reached this way in this presentation of mine.

  • The possibilities and framework of conditions of organisational development at a particular administrative body
    63-70
    Views:
    121

    The demand for the recognition, identification and introduction of measures aimed at improving organizational culture and the efficiency of management and leadership plays a crucial role in the life of every organization, including the law enforcement bodies as well. The tasks and responsibilities of the Hungarian Police Force have changed considerably both in terms of quantity and quality since Hungary’s accession into the European Union first, and since the country’s joining the Schengen Zone. We are now facing problems formerly unheard of (e. g. the integration of the police force and the border guard, joining the Schengen Zone, the emergence of new forms of crime). As border control within the Union stopped, organized crime has become more powerful. The changes are by no means over: in order to improve the subjective sense of security of the population and to advance organizational efficiency, a number of changes are being implemented at present. For the internal security of the member states of the Union and for the improvement of the efficiency of police work in the member states, the use of consciously coordinated management methods is indispensable. These efforts are the subject of this essay.

    A police force is an partially open system, the work of which is influenced by a number of external processes and factors. The organizational culture of a police force is determined by its traditions on the one hand, and by the demands to develop its functions as an authority and a service provider on the other. It is undeniable that any conscious effort in shaping and developing the organizational culture of the police requires special competences and commitment from the leaders of the organization. Furthermore, it is also necessary to modernize the management tasks. It applies to all the levels of leadership, from the head of a patrol to the supreme commander of the police force.

    The organizational scheme of the police force is that of a functional, linear system. Such an organization is characterized by a relatively high degree of inflexibility, a slow and cumbersome reaction to external changes. All these may adversely influence organizational efficiency. It therefore appears to be necessary to examine the present structure of police, and survey the possibilities of modernization. Modernization does not necessarily mean a change in the structure; it may be restricted to changes in organizational culture, the creation of an atmosphere favourable for reforms, and the coordination of diversified structures. In this paper I wish to demonstrate some of the possibilities of improving organizational culture and organization development, based upon the findings of a specific survey.

  • Influences of different organic fertilizers on nutrients of humic sandy soil and on the growth of Spinach (Spinacia oleracea L.)
    23-28
    Views:
    384

    A greenhouse pot experiment was conducted to compare the effects of manure with different origin (horse, cattle), various bedding materials (straw, sawdust) and diverse doses (30 t ha-1, 60 t ha-1) and the impact of food waste compost on the plant growth and the available plant nutrient content of soil. The study was conducted on humic sandy soil and consisted of 9 treatments in a randomized complete block design with four replications. Spinach (Spinacia oleracea L.) was grown as the test crop. The treatments were: 1. unfertilized control; 2. horse manure with straw (30 t ha-1); 3. horse manure with sawdust (30 t ha-1); 4. cattle manure (30 t ha-1); 5 food waste compost (30 t ha-1); 6. horse manure with straw (60 t ha-1); 7. horse manure with sawdust (60 t ha-1); 8. cattle manure (60 t ha-1); 9. food waste compost (60 t ha-1). Plant growth was monitored for 4 weeks. Shoot and root weights per pot were measured, total biomass weight per pot were counted.

    On the basis of the results it can be concluded, that among treatments the application of horse manure with straw enhanced spinach growth most significantly compared to other treatments and to the non-treated control, resulted the highest weights of leaves and roots of spinach. At the same time even small dose (30 t ha-1) of this fertilizer caused increased plant available nitrogen and phosphorus of soil and the higher dosage further increased these values. The horse manure with sawdust applied in lower dose did not alter the leaves and roots weights, but higher portion (60 t ha-1) caused significantly decreased plant biomass. The results proved that the bedding material may significantly alter the composition of manure and may change the plant nutrition effect of organic fertilizer. Cattle manure and food waste compost in both applied doses enhanced plant growth. Both fertilizers increased the plant available nitrogen forms and phosphorus content of soil, but cattle manure caused higher increase.

  • The time, than the resource of the managerial activity
    19-24
    Views:
    79

    The role of the time factor in management is increasing. Change directs attention to the time factor from the point of view of the organisation, and management does the same from that of
    the person. I examined the time management practice of managers of organisations related to agribusiness, and the reaction time characterising the adaption ability of the organisations through a questionnaire survey. I analysed the collected data with scientifically established statistical methods.
    During studying resources I analysed the time factor from two aspects. On the one hand, I wanted to know what role time has in managers’ opinions in increasing company efficiency and
    performance. On the other hand, I asked them how much they consider this resource to be expandable. 

  • A new model for predicting carbon storage dynamics and emissions related to the waste management of wood products: introduction of the HWP-RIAL model
    75-81
    Views:
    154

    The ability of wood products to store carbon allows for their significant contribution to the climate mitigation efforts and the emission reduction commitments set by the EU. In order to optimise the carbon storage capacity of wood products, it is important to take climate mitigation aspects into consideration as much as possible during their production, use and waste management. The aim of this study was to quantify the effects of product development, recycling, and waste management technologies on carbon storage and emissions. In the frame of the ForestLab project, a new model and decision support tool was developed, which is able to predict the duration of carbon storage of wood products and the evolution of emissions from them. The developed HWP-RIAL model (Harvested Wood Product Recycling, Incineration And Landfill model) uses the methodology of the Intergovernmental Panel on Climate Change (IPCC) to calculate emissions, which is also used in the National Greenhouse Gas Inventory report. It combines the IPCC waste model with equations describing the carbon storage and emissions of wood products, and the model is also supplemented with a self-developed recycling and waste routing module. This paper provides insight into the operation of the model by following the life cycle of 200,000 m3 particle board.

  • Investigation of host-specificity of phytopathogenic fungi isolated from woody plants
    155-160
    Views:
    168

    Host-specificity is an important characteristic of fungal pathogens. Changing climate could create more appropriate environmental conditions for phytopathogens, thus formerly host-specify fungi could be able to colonize new hosts. Noxious plant pathogen fungi, which can infect several plant species are well-known worldwide. These genera may expand their range of hosts because of the appearance in new geographic areas due to climate change. This new exposure can result in serious problems in agriculture because of the lack of immunity. The susceptibility of apple tree was studied through testing pathogenicity in vitro with species isolated from walnut twigs and nuts, and identified by ITS sequences. Three of four tested species, Botryosphaeria dothidea, Diaporthe eres and Diplodia seriata colonized and necrotized the infected apple branches, while Juglanconis juglandina was not able to infect the twigs. Members of Botryosphaeriaceae were the most virulent, causing the largest lesions in the fastest way. This experiment draws attention to the threat of new host-pathogen connections, which can arise because of the favourable weather conditions and can spread between neighbouring cultures. 

  • Impact of tillage systems on maize emergence
    129-136
    Views:
    81

    In Europe, there has been a significant change in the way tillage is approached in recent years. This change is due to a growing awareness among farmers, politicians and society as a whole that soil is not a renewable resource in itself. From an agricultural point of view, the greatest impact on soil condition can be achieved through the use of the applied tillage systems.  My research takes this approach as a basis when examining the different tillage systems and their impact on the environment. In this context, conventional and a variety of no-tillage systems are examined in this paper. As a next step, it is examined how the environmental conditions created by the different tillage systems influence the emergence of maize hybrids. The analyses are carried out in a multi-factorial, long-term tillage field experiment. The same batch of the same hybrid seed was sown in several crop years, and the effects of environmental conditions on the emergence process were examined. Environmental effects and emergence-related uptake were measured in the examined plots. Measurements of environmental effects included air temperature, precipitation, soil temperature measured at seeding depth, as well as % cover of stem residue on the surface in the treated plots. The first emergence time measurements of the sown crop in the plots of each treatment were compared and relationships between these factors were investigated.

  • Investigation of the impacts of the by-product of sewage treatment on some characteristics of maize in the early growth stage
    77-82
    Views:
    75

    The use of sewage sludge on arable land has been widespread for many years. This by-product, treated as waste, can provide valuable nutrients to the soil, but the applied amount of sewage sludge to arable land is limited. The possibility of application of sewage sludge is essentially determined by the composition of the sludge. The goal of the experiment was to demonstrate that the physiological, morphological, and biochemical parameters of maize (Zea mays L. cv. Armagnac) linearly change with increasing concentrations of sewage sludge (25%, 50%, and 75% as m/m%). The experiment was set up in a glasshouse. The following parameters were investigated: plant height, relative chlorophyll content, photosynthetic pigments (chlorophyll-a, chlorophyll-b, carotenoids), and leaf proline and malondialdehyde (MDA) content, and PS II quantum efficiency in the 3-leaf stages of the plants. Sewage sludge applied in lower doses had a beneficial effect on the initial growth of maize. The relative chlorophyll content was significantly higher in all treatments compared to the control. There was no significant difference in the maximum quantum efficiency of PS II reaction centers among the treatments. In this experiment, different concentrations of sewage sludge treatments had different impacts on the MDA and proline content of maize leaves. The proline content was significantly higher in all treatments, while the MDA content did not change significantly compared to the control.

  • Relationship between the change of soil moisture content of different soil layers and maize yield
    19-25
    Views:
    186

    The development of chernozem soil water management and its relationship with maize yields was studied in a 30-years long-term field experiment with different crop-rotation systems (mono-, bi- and triculture), in three crop years with different natural precipitation: a drought (2007), a wet (2008) and a dry (2009 one. The relevant soil layer was divided to three sub-layers: (0–60 cm, 61–120 cm, 121–200 cm) in which the development of soil moisture content was investigated during the whole vegetation. From the results it can be stated that change of the water stock of the upper soil layer (0–60 cm) was the most intensive. Both the direct effect of natural precipitation and irrigation could be observed in the most obvious way in it. Yield result of maize and the highest water supply deficit values in the vegetation were compared in our work too. According to the results it was revealed that among the three studied crop rotation systems it was the monoculture, the success of production of which depends the most of water supply. The most favourable crop rotation system was the triculture from both the aspect of the yield of produced crops and the favourable soil properties too.

  • Heat stress of cattle from embryonic phase until culling
    11-22
    Views:
    325

    Heat stress becomes a serious problem in the livestock sector as it affects cows' performance negatively. The objective of this paper review is to investigate the effects of heat stress during the different phases of the life cycle of cows; embryos, calves, heifers, and cows. Heat stress during early maternal gestation affects the ability of embryos to develop increasing the risk of abortion and early embryonic death. Heat stress during late maternal gestation affects the performance of calves and heifers later in their life, as it reduces growth performance, conducts physiological changes, impaired immunity, changes the behavior, and reduces the length and intensity of the estrus in heifers with decreasing in milk production in the first lactation. On the level of cows, milk quality and production, meat quality, and the final body weight decrease under hot temperatures. Heat stress decreases the conception rate, alters follicle growth, and estrous symptoms. Hormones secretion and physiological changes because of the heat stress conduct to impair the immunity system, and in oxidative stress and death in some cases. Same as for calves and heifers a change in the behavior of cows was detected in order to decrease their temperature.

  • The marigold (Calendula officinalis L.) drug essential oil agents change under different fertilization settings in small plot trial
    57-60
    Views:
    182

    During our research we investigated the marigold's (Calendula officinalis L.) nutrient requirements with different fertilization setting in small-plot trial. We measured SPME (Solid phase microextraction) and GC-MS (gas chromatograph-mass spectrometer) we examined the effects of the different fertilization settings for the herb's main active ingredients of essential oil's percentage.

    Based on the results, it was concluded, the essential oil agents' percentage breakdowns significantly depending on the cropping technologies. Besides that it is possible, based on Pearson's correlation test the marigold essential oil agents relationship can also be a major factor.

  • The impact of climatic factors on the relative chlorophyll content and yield of a maize hybrid in a long-term experiment
    71-77
    Views:
    234

    The impact of the climatic factors of crop year on the relative chlorophyll content of maize was examined for three years. The examinations were carried out on the Látókép Experiment Site of the University of Debrecen on calcareous chernozem soil in a small-plot, non-irrigated long-term field experiment with strip plot design. In addition to a non-fertilised (control) treatment, nitrogen (N) fertiliser doses were applied as base and top dressing. The 60 and 120 kg N ha-1 base dressing doses were followed by two top dressing doses at the V6 and V12 phenophases.

    Averaged over the different fertiliser treatments, SPAD readings increased in all three years as the growing season progressed. The highes SPAD value increase was observed in the average crop year (2017) at the V12 phenophase (11.8), which further increased at the R1 phenophas, by 3,7. No significant Spad value difference was observed between the average (2017) and the dry year (2018) at the V6 growth phase. However, in the wet crop year (2016), the V690 treatment provided the statistically highest relative chlorophyll content (46.8). At the V12 phenophase, the base dressing dose of 120 kg N ha-1+30 kg N ha-1 (V6150) showed to be successful in two years (2016 and 2018), while in 2017, the base dressing dose of A60 was successful. The impact of crop year on relative chlorophyll content can be clearly shown at the R1 growth stage. In all three years, the significantly highest relative chlorophyll content could be achieved at different nutrient levels: A60 in 2016, V6150 in 2017 and V690.

    In a wet year (2016), higher yield could be achieved as a result of the 60 kg N ha-1 base dressing and 30 kg N ha-1 at the V6 growth stage (V690) as top dressing in comparison with 2017 and 2018, when higher fertiliser dose (120 kg N ha-1 base dressing and 30 kg N ha-1top dressing at the V6 growth stage) was needed to achieve a significant yield surplus.

    Altogether, averaged over the different treatments, the highest yield (12.48 t ha-1) was observed in the wet year, when the relative chlorophyll content was also the highest (50.6).

  • Improvement of black locust (Robinia pseudoacacia L.) growing under marginal site conditions in Hungary: case studies
    129-133
    Views:
    362

    In Hungary, black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species growing mostly under unfavourable ecological conditions for forest management. Due to climate change effects, its importance is increasing in many other countries, too. As a result of a selection programme, new black locust clones were tested in clone trials. Juvenile growth of 12 micropropagated black locust clones in two plots series established at different dates were evaluated in central Hungary under marginal site conditions. At age of 7 the clone R. p. ‘Bácska’ (‘KH 56A2/5’), at age of 10 the clones R.p. ‘Homoki’ (‘MB17D3/4’) and ‘PV201E2/4’ appeared to be especially promising for mass production. Based on the data obtained from the performed trials, it can also be concluded that tissue culture can be considered as a suitable tool for propagating superior individuals and offers new prospects for the rapid cloning of selected genotypes used for plantation forestry.

  • The effect of washing for the shelf-life parameters of spinach (Spinacia oleracea L.)
    131-135
    Views:
    123

    Spinach is a very popular green leafy vegetable because of its versatile usage and beneficial for the health. However, spinach may contain several pathogen bacteria: Escherichia coli, Klebsiella spp., Salmonella spp., Enterobacter spp., Citrobacter spp., Shigella spp. and Listeria monocytogenes, which can cause several serious health problems. This study investigates the effects of washing with citric acid for the shelf-life parameters of spinach in comparison to the effect of washing with water and control. Washing of spinach with 0.5% citric acid solution decreased the elasticity of the spinach leaves, as well as the chlorophyll content. On the other hand, the total plate count, as well as the yeast and mold count could be decreased with this treatment, but difference was not detectable at the forth storage day. The fecal indicator E. coli did not change, indicating washing was not effective in this case. Further optimisation of treatment and storage conditions may decrease microbial risk of fresh spinach consumption without decreasing its sensory quality.

  • Monitoring the oxygen level in the Szarvas-Kákafok Deadarm
    170-173
    Views:
    86

    The 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.

  • Examination of drought stress of two genotype maize hybrids with different fertilization
    53-57
    Views:
    129

    In the growing season of 2019, we analysed stress resulting from climatic factors on maize hybrids of different genotypes, with the aim of gaining a better understanding of the physiological responses of each hybrid, which might support the elaboration of a cost-effective irrigation plan.

    Our experiments were carried out at the Látókép Experimental Station of the University of Debrecen on calcareous chernozem soil in a small-plot long-term field trial with strip plot design. In the scope of the experiment, N-fertilizer doses were applied as basic fertilizer and top-dressing in addition to the non-fertilized (control) treatment. The 60 and 120 kg N/ha doses applied as basic fertilizers in the spring were followed by top-dressing in the V6 phenophase with a +30 kg N/ha dose. Measurements were carried out with the involvement of the Renfor early (FAO 320) and Fornad (FAO 420) late maturity hybrids-

    The stomata of the plants became more and more closed with the progression of the phenological phases; their stomatal conductance decreased. However, the hybrids responded differently to environmental stress. In the case of the Renfor hybrid, the highest conductance (669 mmol/m2-s) was recorded in the V12 phenophase with the 150 kg N/ha treatment. The stomata were more open due to the high turgor pressure, allowing plants to evaporate properly. The plant was in its worst physiological condition on 2nd July, at the time of the appearance of the last leaf in the case of the 120 kg N dose (224 mmol/m2-s). The value measured in the V12 phenophase has already shown that the stomata were closing due to the self-regulating system of the plant. It would have been necessary to dispense irrigation water following the measurement. This confirms the finding that water stress can be prevented by measuring stomatal conductance.

    In the case of the Fornad hybrid, stomatal conductance was the highest on 12th June (630 mmol/m2-s) in the 90 kg N/ha treatment and it was the lowest (183 mmol/m2-s) in VT (emergence of the last leaf) phenophase in the 60 kg N/ha treatment. In this case, the appropriate time for applying irrigation water would have been early July, when the conditions for the plants were still adequate. Subsequently, the stomata began to close due to a reduction of the water resources available to them.

    There was a significant correlation between soil moisture and stomatal conductance, as well as between temperature and stomatal conductance.