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  • The effect of supplemental pig milk replacer on carbohydrate metabolism – a review
    67-71
    Views:
    194

    The aim of this review is to examine the effect of milk supplementation on pigs’ carbohydrate metabolism. These parameters regulate the growth of piglets, the nutrient intake and the period of pre-weaning. Due to the increased litter size, the sow milk yield reaches an individual maximum. The individual maximum has not increased proportionally with the number of piglets born alive. The use of liquid milk supplementation may give the opportunity to keep these large litters. The examined hormones are insulin, insulin-like growth factor, growth hormone, growth hormone releasing hormone, ghrelin and leptin. This review seeks to find these hormones’ interactions.

  • Comparision of growth of mature all-female and mixed-sex Common carp (Cyprinus carpio L.) stocks in RAS
    65-68
    Views:
    421

    The common carp (Cyprinus carpio L.) is the most important fish species in Hungary, it is more than 70% of the total Hungarian fish production. The common carp production is important not only just in Hungary but in Middle-East Europe, as well as Southeast Asia. Majority of the production comes from fishpond culture. If the production sector wants to meet the increasing customer demands, there is need to intensify research on the intensive fish production opportunities for example all-female common carp technologies. The all-female technology is one of a genom-manipulation technology. Its production showed better growth rate than mixed-sex population in pond culture. Our experiment combined the recirculation aquaculture system (RAS) and the all-female common carp stocks intensification technologies. The reason for the experiment, is that there are no result about the growth of all-female common carp growth in RAS.

    The experiment used the „Tatai grey scale type” common carp stocks. We propagated two all-female stocks (T2 and T3) and a control group (TK). Due to technological characteristics of RAS, the water quality parameters were the same for all treatments and corresponded to the technological tolerance of common carp.

    The experimental period was from July 10, 2019 – November 20, 2019. Result of growth performance showed that the growth of mixed-sex stock was significantly higher than all-female stocks; (Control=3692.0±590.5g, T2=3438.8±415.4g, T3=3294.1±659.1g). Feed conversation ratio (Control=1.3±0.1 T2=1.5±0.2 T3=1.6±0.5) and SGR% (Control=0.8±0.0 T2=0.7±0.1 T3=0.7±0.1) were similar.

    By the results it can be said the all-female common carp technology has neither advantages nor disadvantages compared to the mixed-sex stock. The all-female technology can be beneficial if the consumers need female common carps. It is worth continuing the experiment and examine how the stocks will perform above 3kg body weight.

  • Examination of the efficacy of different fungicides against Macrophomina phaseolina and Sclerotinia sclerotiorum in laboratory conditions
    21-24
    Views:
    188

    Macrophomina phaseolina and Sclerotinia sclerotiorum are two significant fungal pathogens of sunflower. M. phaseolina causes charcoal rot and ashy stem blight in several important crop species. Sclerotinia sclerotiorum causes white mold disease which can occur as middle stalk rot, head rot and premature plant death. Due to the wide host range of the two pathogens and their survival structures, crop rotation cannot provide sufficient protection against them. In our experiment, we selected two fungicides, Mirage and Prosaro, which are widely used in practice, and we tested their efficacy against the two pathogens. The efficiency of these fungicides was tested at a concentration of 10; 20; 50; 100 and 500 ppm. The Prosaro totally inhibited the mycelial growth of both pathogens at a concentration of 50 ppm, 100 ppm and 500 ppm. The Mirage caused total mycelial growth inhibition in all treatments against both pathogens.

  • Effect of different weaning time on the growth and survival ofCommon carp (Cyprinus carpio L.) larvae
    55-59
    Views:
    280

    Within our experiment, we studied the combined effect of live food application and feed training on the production parameters of carp larvae. In addition, we examined whether there is a difference in the growth rate and survival rate of the specimens of Szeged mirror landrace reared in similar stocking density but with different treatments.

    Specimens of Szeged mirror landrace from induced propagation were placed into 12 pieces of 40-liter aquaria. For the 4 different treatments, (K, A3, A6, A9), live food (Artemia salina) was fed, as well as feed training was applied.

    We also sought to find an answer as to how our feeding and rearing conditions can affect the production parameters of common carp fries and what impact these conditions may have on their survival rates. At the end of the 2-week experiment we determined the individual weight gain of the carp fries, their survival rate and the biomass growth. The purpose of the study is to examine the optimum timing of shifting from live food to feed for carp larvae.

  • Influences of different organic fertilizers on nutrients of humic sandy soil and on the growth of Spinach (Spinacia oleracea L.)
    23-28
    Views:
    292

    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.

  • Nest-site preference of Hooded Crow (Corvus cornix L.) in Debrecen, Hungary
    13-17
    Views:
    117

    In the past decade, the population of the Hooded Crow has shown significant growth in Debrecen, Hungary. The aim of this study was to become acquainted with the nest-site selection behavior of Hooded Crows in urban spaces. While our research revealed that the Hooded Crow is not particular when it comes to selecting among tree species for nesting, we did notice differences regarding nesting height. Hooded Crows living in the city build their nests higher up than those living outside Debrecen’s city limits. We also discovered a slight, insignificant difference between nesting heights and tree species, which is probably due to the different characteristics of the given tree species. As for nesting heights, we found that in typical urban habitats there were no relevant differences. However, when we compared these habitats in pairs, it came to light that nesting heights -when comparing solitary trees - wood segments and tree rows - wooded segments- did show significant differences, which can be explained by the various conditions provided by the habitats mentioned.
    In summary, the following results emerged from our research:
    1. The Hooded Crow prefers approximately the same nesting heights in all kinds of habitats, urban environment and tree species.
    2. The nesting height does not significantly depend on the habitat itself or on the tree species.

  • Water managed properties of apple and pear trees based on lysimeters
    129-132
    Views:
    135

    A significant proportion of the aboveground green and dry weight of the plant is constituted by foliage. The canopy is an important factor of plant growth. On the one hand, the canopy absorbs solar energy, which is necessary for photosynthesis; on the other hand, it accumulates the nutrients absorbed by the roots, and most of the water-loss occurs through the foliage. The determination of the full canopy is not an easy target. In our research, we developed a measurement method to determine the leaf area. With the parameters of the examined tree (leaf length and maximum width) and the data of the ADC AM 100 leaf area scanner, we determined the k-value, with which we can easily and fast evaluate the leaf surface. Furthermore, we defined from the water balance of compensation lysimeters the cumulative transpiration of fruit trees and the efficiency of water use of trees. From the examined trees were made a 3D depiction, which show the shape, branching and the location of trees.

  • Preliminary results of the combined production of duckweed Spirodela polyrhiza and common carp (Cyprinus carpio) in an aquaponic system
    83-89
    Views:
    65

    As 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.

  • Comparison of the technological background of aquaponic systems
    47-52
    Views:
    260

    Aquaponics is the combined culture of fish and plants in recirculating aquaculture systems, an ecologically sustainable horticultural production technique with long traditions.

    The objective of this study is to compare flood-and- drain, and the water crossflow system and examine the differences in the water quality, fish yield and plant growth parameters for Common carp (Cyprinus carpio) and basil (Ocimum basilicum). During the study, water quality parameters of two treatments were compared in temperatures, pH, EC and NON were significantly different (p <0.05). Leaf area of the basil plants grew to an average of 20.37 cm2 (± 9.02 cm2). The plants’ biomass production was significantly different (p< 0.05) in the two systems. The biomass production showed lower yield, 458.22 g (± 214.59 g) in the constant flow system that in the flood- and- drain system 692.9 g (± 175.82 g). Fish Growth parameters were better in constant flow system (FCR 5.48 g/g ± 0.19). However, the specific growth rate (SGR) demonstrated that fish grew faster in flood- and- drain system 1.38 %/day (± 0.29).

  • The impact of climatic factors on the relative chlorophyll content and yield of a maize hybrid in a long-term experiment
    71-77
    Views:
    193

    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).

  • Impact of nitrogen and sulphur fertilization on the growth and micronutrient content of spring wheat (Triticum aestivum L.)
    211-219
    Views:
    166

    Micronutrients are as important as macronutrients for crops. Each micronutrient has its own function in plant growth. Zinc is important for membrane integrity and phytochrome activities. Copper is an essential micronutrient required for the growth of wheat. Manganese is required for enzyme activation, in electron transport, and in disease resistance. The pot experiment was set up in greenhouse on calcareous chernozem soil Debrecen-Látókép with a spring wheat. In certain development stages (according to BBCH growth scale of wheat), at the beginning of stem elongation (29–30), at the heading (51–59), at the flowering (61–69) stage three average plants were removed from all pots for analysis. Fresh and dry weight of the plant samples were measured. Plant leaves after drying were digested by HNO3-H2O2 methods and manganese, zinc and copper contents of plant were quantified by atomic absorption spectrophotometry. At the flowering stage, when the nutrient uptake of plants is the most intensive, the weight of wheat ranged between 0.94–1.57 g plant-1. In this development stage, the NS2 treatment produced the highest weight of wheat, and compared to this the NS3 treatment decreased that value already. The results show unfavourable effect of NS3 treatment. On the basis of microelement content of wheat and the weight of a plant, nutrient uptake by plant were calculated. At the beginning of growth the starter treatment had positive effect on Cu-uptake compared to the NS1 treatment, where the same dose of fertilizer was stirred into the soil. Wheat is very sensitive to copper deficiency, so copper dissolved by starter treatment could be favourable to the early development of wheat. At flowering stage the Zn-uptake of wheat became the highest and it was between 133.7–234.6 mg plant-1. The Mn-uptake of wheat plant was higher than the Cu- and Zn-uptake of wheat.

    This phenomenon can be explained by the fact that the untreated soil had higher Mn-content, than Cu- and Zn-content. To summarize the results, it can be stated, that the copper uptake of wheat was more affected by the different treatments in the stage of stem elongation, while Mn- and Zn-uptake of wheat were influenced primarily in the stage of heading and flowering.

  • The effect of dissolved oxygen on common carp (Cyprinus carpio) and basil (Ocimum basilicum) in the aquaponics system
    89-96
    Views:
    274

    Aquaponics is an integrated system that combines fish farming (aquaculture) and hydroponic plant production. The objective of this study was to examine how the level of dissolved oxygen with or without an air pump affects water quality, fish output and plant growth parameters for common carp (Cyprinus carpio) and basil (Ocimum basilicum).

    Ebb – and flood aquaponics systems (with automatic syphon) was used. Two treatments were set in this experiment, one of which was the aquaponics system without air pump (unit I), where water of the plant bed was pumped two directions, one falling back to the fish tank oxygenating the water the other was pumped to the hydroponics unit. The other system (unit II) was designed with an air pump.

    In the course of the study, water quality parameters, such as oxygen saturation, dissolved oxygen (DO), electrical conductivity (EC) and nitrite were significantly different (p<0.05). Total basil biomass was higher in unit II. (5367.41 g). The final biomass of common carp were
    2829.45 g ± 79.24 and 2980.6 g ± 64.13 g in unit I and unit II respectively. Weight gain (WG) and specific growth rate (SGR) showed no significant differences (p>0.05) between the treatments. 

  • The Role and Significance of Soil Analyses in Plant Nutrition and Environmental Protection
    3-8
    Views:
    80

    Hungary has a rich history of soil analyses and soil mapping. Our main tasks today are the preservation of soil fertility as well as balancing the goals of production and environmental protection. The main requirement of agricultural production is to adapt to ecological and economic conditions.
    In a series of consultative meetings in the past seven years, representatives from Central and Eastern Europe have analyzed nutrient management practices in their respective countries. According to a joint memorandum agreed upon in 2000, in the countries awaiting accession, the quantity of nutrients used per hectare is considerably smaller than the Western-European usage targeted through special subsidies. The current low nutrient usage contradicts the principles of sustainability and that of the efficient use of resources, jeopardizing soil fertility.
    In Hungary, the use of inorganic fertilizers underwent a dynamic development, which manifested itself in an almost tenfold usage growth between 1960 and 1985. This growth slowed down somewhat between 1985 and 1990 and then reduced dramatically after 1990, reaching record lows at the usage levels of the 60s. The nutrient supply has had a negative balance for the last 15 years.
    The increasing and then decreasing usage trends can equally be detected in the domestic yield averages of wheat and corn as well as in the nutrient supply of soils. Yields were the largest when usage levels were the highest, and decreased thereafter. Draughts have also contributed to smaller yields. The dramatic decrease in the use of inorganic fertilizers when adequate organic fertilizers are lacking endangers our soils’ fertility.
    About 50% of soils in Hungary are acidic. Acidity is mostly determined by soil formation, but especially on soils with a low buffering capacity, this acidity may intensify due to inorganic fertilizers. Sustainable agriculture requires the chemical improvement of acidic soils. According to their y1 values, the majority of our acidic soils need to be improved. This chemical soil remediation is required in 15% of the acidic soils, while it’s recommended for another 20% of these soils.
    Results of the analyses conducted in the framework of the soil-monitoring system set up in Hungary in 1992 show that in 95% of the analyzed samples, the toxic element content is below the allowable limit. Cultivated areas are not contaminated; toxicity above the legal level was found only in specific high-risk sampling areas: in the vicinity of industry, due to local overload. The basic principle of sustainable agriculture is to preserve soil fertility without undue strain on the environment. The intensity of the production needs to be considered according to the conditions of the site; i.e.; nutrient management needs to be site-specific. It is recommended to differentiate three types of cultivated land in terms of environmental sensitivity: areas with favorable conditions, endangered areas, and protected areas, and then to adopt nutrient management practices accordingly. To meet all the above-mentioned goals is impossible without systematic soil analysis. Tests conducted by the national monitoring system cannot replace regular field measurements.

  • Managing risk using real options in company’s valuation
    125-132
    Views:
    133

    The valuation of company is very important because provides information about the current value/situation of company, and through this, provide the opportunity of choosing the best company’s growth alternatives. The future strategic decisions are characterized by lack of knowledge, information, so all measures of company’s growth are closely linked with uncertainty and risk. The company’s valuation process is also related with uncertainty and risk. The risk may result both from the assessed assets and the technique used. In literature, we could find three approaches for risk management: capital budgeting based method, methods based on portfolio analysis and real options approach of risk management. Among them, the real options based methods is the most revolutionary approach for risk management. The advantages of the method, consists in the fact, that the process of establishing strategic decisions integrates the possibility of reversibility, delay and rejections, which isn’t it possible at two previous methods. The method also takes into account the total risk of company, so both the company-specific and systematic risk. In this study, I have used one of the best-known real option based method, the Black-Scholes model, for determining the option’s value. Determination of option value is based on the data of enterprise, which was tested Monte Carlo simulation. One of the basic assumptions of the Black-Scholes model is that the value of option is influenced by several factors. The sensitivity of option’s value could be carried out with so-called “Greeks”.. In the study the sensitivity analysis, was carried out with indicators Delta (Δ), Gamma (Γ) and Vega (ν). The real options based risk management determinations were performed in the R-statistics software system, and the used modules are 'fPortofio' and 'mc2d'. By using of real options method, I have calculated the average value of company capital equal with 38.79 million. By using simulation was carried out 1000 runs. The results of this show a relatively low standard deviation, small interquartile range and normal distribution. In the calculation of indicator Delta, could be concluded the value of company moves in 0.831 proportion to the price of options, the standard deviations of index is low, so the real option based method could be used with success in company’s value estimation. The Gamma index shows the enterprise value is sensitive just for large changes. The result of Vega reflects the value of option, so the company’s value volatility, which is small in this case, but this means a volatility of value. In summary, we can conclude that the call options pricing model, well suited for the determination of company’s value.

  • Examining the production parameters of European perch (Perca fluviatilis) juveniles under different lighting conditions
    149-153
    Views:
    160

    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.

  • Evaluation of water balance in apple and pear trees
    193-198
    Views:
    102

    A significant proportion of the aboveground green and dry weight of the plant constitutes the foliage. The canopy is an important factor
    of plant growth. On one hand the canopy absorbs the solar energy, which is necessary for the photosynthesis, on the other hand accumulates
    the absorbed nutrients by the roots, and the most of the water-loss happens through the foliages. The determination of the full canopy is not
    an easy target. In our research we developed a measurement method to determine the leaf area. With the parameters of the examined tree
    (leaf length and maximum width) and the data of ADC AM 100 leaf area scanner we determined the k-value, with which we can easily and
    fast evaluate the leaf surface. Furthermore we defined from the water balance of compensation lysimeters the cumulative transpiration of
    fruit trees and the efficiency of water use of trees.

  • Evaluation of chickpea (Cicer arietinum L.) in response to salinity stress
    105-110
    Views:
    201

    Soil salinity is a severe and expanding soil degradation problem that affects 80 million ha of arable lands globally. Chickpea (Cicer arietinum L.) is very sensitive to saline conditions; the most susceptible genotypes may die in just 25 mM NaCl in hydroponics. Approximately 8–10% yield loss in chickpea production is estimated due to salinity stress. However, it is still not established why chickpea is so susceptible to salt affection. Salinity (NaCl) impedes germination of seeds, though chickpea varieties considerably differ from one another in this respect. Some chickpea genotypes are more tolerant in the stage of germination, tolerating even 320 mM NaCl. The reasons of this variation are unrevealed; there is a shortage of knowledge about the germination abilities of chickpea genotypes in saline conditions. Nevertheless, the effect of salt stress on vegetative growth can be analysed in hydroponics, in pot or field conditions, regardless the experimental environment, the ranking of genotypes regarding salt resistance is coherent. Chickpea genotypes can be different in their ability to retain water, maybe under salt affection; the more salt tolerant lines can maintain higher water content in the shoots, while the more sensitive ones cannot. The identification of salt tolerant chickpea landraces based on developing genetic variability is a suitable strategy to combat against salinity problems arising in arid and semi-arid areas.

  • Investigation of the impacts of the by-product of sewage treatment on some characteristics of maize in the early growth stage
    77-82
    Views:
    38

    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.

  • Improvement of black locust (Robinia pseudoacacia L.) growing under marginal site conditions in Hungary: case studies
    129-133
    Views:
    317

    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.

  • Does the feeding frequency influence the growth performance of European perch juveniles (Perca fluviatilis) during intensive rearing?
    123-128
    Views:
    120

    The European perch (Perca fluviatilis) is a predatory fish species. Its aquaculture production is increasing worldwide. Feeding and the frequency of feeding are important elements of intensive fish rearing. The aim of our experiment was to examine the optimal distribution of the amount of feed, at the same feed rations. The experiment lasted 42 days. Three treatments were applied in 4–4 replications. The first treatment was feeding twice per day (T2), the second treatment was feeding three times a day (T3), and the third group was fed four times a day (T4). 10 European perch juveniles were stocked per tank, with an individual mean body weight of 3.93 ± 0.06 g at the start of the experiment. The survival rate (S%) was above 90% for all treatments. The T2 treatments produced the most favourable harvest weight (13.96 ± 0.14 g) and specific growth rate (SGR = 3.08 ± 0.01% day-1), but no significant differences were observed between groups. In terms of feed conversion ratio, the best result was obtained by (T3) (FCR =1.06 ± 0.18 g g-1), but no significant difference was found for this indicator neither. The results of the trial indicate that the feeding frequency does not influence the production parameters.

  • Heat stress of cattle from embryonic phase until culling
    11-22
    Views:
    246

    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.

  • Effect of Moringa leaf extract and set size on the bulb weight, diameter and yield of onions (Allium cepa L.)
    127-131
    Views:
    229

     Studying the use of natural extracts or biostimulants in improving vegetable plants is the current needs as an alternative way to the use of chemical products. This experiment was carried out to evaluate the effect of Moringa oleifera leaf extract (MLE) as a natural growth regulator on bulb diameter, weight and yield of onions ‘Texas Early White’ cultivar. Therefore, three concentrations (control, 2%, 4% and 6%) of MLE and three different onion set sizes [small (3±1 g/set), medium (6±1 g/set), and large (10±1 g/set)] were prepared in a randomized complete block design with three replications and plant spacing 20×15 cm. MLE was applied as a foliar spray directly onto the plants with the amount of 25 ml/plant every two weeks from sprouting to maturity. The achieved results indicate that the interaction of foliar spray with moringa leaf extract 4% and large set size of 10±1 g/set gave the highest value of the total yield 4802.7 g m-2, while the lowest yield 1531 g m-2 was recorded in the interaction of control and the smallest set size of 3±1 g/set. Also, a significant difference was recorded in bulb diameter separately. Thus, the largest bulb diameter 68.90 mm was obtained from the planting of the largest set size 10±1 g/set with 4% of MLE while the smallest bulb diameter 38.40 mm was recorded from the smallest set size 3 ±1 g/set with control treatment. Similarly, a significant effect was recorded in both set size and MLE separately. The highest bulb diameter 58.71 mm was achieved in the planting of the largest sets 10±1 g/set, while the lowest diameter was 42.12 mm in the planting of the smallest set size 3 ±1 g/set. Similar results were recorded for the bulb weight and total yield. The concentration of 4% MLE produced the highest bulb weight 99.74 g/bulb and yield 3324.5 g m-2, while the lowest bulb weight and yield was obtained in the control treatment 55.61 g/bulb, and 1869.3 g m-2. Consequently, the results indicate the positive effect of Moringa leaf extract which can be applied as a natural substance in the form of foliar spray at critical growth stages to improve the growth and yield of dry onions.

  • 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:
    67

    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.

  • Establishing biotic stress tolerance of maize (Zea mays L.) by measuring hydroxamic acid contents
    107-112
    Views:
    182

     

    Cyclic hydroxamic acids are the most considerable secondary metabolites in grasses and their main task is to protect these species from pathogens and pests. The cyclic hydroxamic acid content and common smut susceptibility were examined in our experiments. 27 maize hybrids were used for experimental plants in a climate room, where the plants were grown on a nutrient solution. An infiltration method was used for the inoculation of the plants. The total quantity of cyclic hydroxamic acids was determined and the ratio of infected plants and the ratio of inhibition was determined, too. Based on our results, on the basis of all hybrids’ data, the total hydroxamic acid content of the infected plants was higher than in the control. On the level of individual hybrids, only 9 of them had higher cyclic hydroxamic acid content in the case of infection. Increase in cyclic hydroxamic content induced by the fungus in this case is a tool for the fungus to suppress other pathogens and pests. Amongst the hybrids’ cyclic hydroxamic acid contents, significant differences were detected in the control and in the infected treatment, too. The so-called “sweetcorn” hybrids showed high level of cyclic hydroxamic acid content. According to the differences amongst hybrids, homogenous groups were created which groups differed in the case of control and infected treatment, because of the difference in increase of cyclic hydroxamic acid content. The examined hybrids showed different levels of infection and different rate of growth inhibition for the effect of inoculation. According to the infection caused damage hybrids were ranked. Infection caused notable damage for hybrids Prelude, Desszert 73, DKC5276 and DK440.

  • Promising Leuce poplar clones in sandy ridges between the rivers Danube and Tisza in Hungary: a case study
    111-113
    Views:
    214

    An intensive integrated research and development work has been carried out on the improvement of Leuce poplars including primarily the native white poplar (Populus alba L.) and its natural hybrid grey poplar (Populus × canescens). More than 70 percent of the Leuce poplar stands can be found on calcareous sandy sites in the Danube–Tisza region, so they play a significant role in the poplar management of this part of the country. The most important task ahead of Hungarian poplar growers is to improve the quality of poplar stands and plantations based on selecting new clones and cultivars. The growth and yield of four promising Leuce poplar clones was evaluated on a marginal site in central Hungary. The clones ‘H 425-4’ (Populus alba L. × Populus alba L.), and ‘H 758’ (Populus alba L. Mosonmagyaróvár 124) seem to be suitable for wood production, while the ‘H 427-3’ (Populus alba L. × Populus alba L. cv. Bolleana) and ‘H 422-9’ (Populus alba L. × Populus grandidentata (Michx)) clones (with decorative stem form) could be better used for tree lines and ornamental plantations.