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  • Economic questions of maize production on different soil types
    289-292
    Views:
    264

    The requirements and objective of cultivation are in constant change. For example, different cultivation systems are developed for the purpose of soil protection, the preservation of its moisture content and on soils with various precipitation supply or production site conditions. Traditionally, one of the most important cultivation aims is crop needs. Further cost saving in fertilisation and crop protection can only be achieved by reducing the quality and quantity of production or it cannot be achieved at all. Furthermore, the costs can be significantly reduced by means of the rationalisation of cultivation. Energy and working time demand can also be notably reduced if ploughing is left out from the conventional tillage method. The key requirement of economicalness is to perform the cultivation at the optimal date, moisture level and the lowest possible cost.
    Within production costs, the cost of cultivation is between 3–17%, while they are between 8–36% within machinery costs. It is the vital condition the usability of each technological method to progressively reduce costs. Our evaluation work was carried out with the consideration of the yield data obtained from cooperating farms and the experiment database of the Institute for Land Utilisation, Regional Development and Technology of the Centre for Agricultural and Applied Economic Sciences of the University of Debrecen. Three technological methods (ploughing, heavy cultivator and loosening tillage) were used on several soil types which differ from in terms of cultivability (chernozem, sandy and sandy clay soils) from the economic/economical aspect. We examined the sectoral cost/income relation of maize production as an indicator plant. The maize price during the analytical period was 45 thousand HUF per t. On chernozem soils, the production of maize can be carried out on high income level, while maize production on sandy soils has a huge risk factor. The role of cultivation is the highest on high plasicity soils, since they have a huge energy
    demand and the there is a short amount of time available for each procedure in most cases.

  • Foliar treatments of Sugar beet
    55-59
    Views:
    373

    The yield and quality of the sugar beet are mainly determined by the plant production system, thus we studied the effect of mineral fertilization. Our field trials were carried out in 2005 and 2006 in Hajdúböszörmény, at two sites. We studied the effect of sulphur (Cosavet DF), copper (Kelcare Cu) and two foliar nutrients with high active agents. Treatments were replicated four times.
    We took root and leaf samples at 4 week intervals, starting in August. The quality of root (sucrose, potassium, sodium and alfaamino N content) was determined from filtrated beet broth, by an automatic beet laboratory system, called VENEMA. Leaf samples were measured with ICP-OES.
    We found that the crop and the sugar yield were significantly influenced by the foliar treatments. 

  • Comparative Study on Different Water Bodies and their Sediments
    17-21
    Views:
    236

    Hungary is rich in natural water resources, therefore investigation of these biotopes is an important task. The Szarvas- Kákafok deadarm is the largest horse-shoe lake of the Tiszántúl, its lenght is 28 km. It has an important role in recreation and agricultural utilization. The quality of the deadarm is influenced by the river Körös, but also by communal and agricultural pollution. Our goals were to estimate the intensity of the
    sedimentation processes, and the water- and the sediment quality as well. Also, we examined an artificial wetland system, constructed by the Fish Culture and Irrigation Research Institute, Szarvas.
    The calculated sedimentation was 0.4-0.5 cm year-1, which indicated an intensive eutrophication process. The constructed wetland system was able to decrease the organic load of the intensive fish culture company. On the basis of our TOC measurements, the organic matter content of the effluent water remained whitin the water quality limits.
    The changes of the material cycling could be more intense in the water body, then in the sediment. The oxido-reduction potential of the sediment could indicate the ecological state of the shallow lakes, therefore it could be an easily measurable indicator in the water classification.

  • Relationships between nutrientsupply, genotype and some physiological properties of winter wheat
    141-145
    Views:
    437

    The chlorophyll content (SPAD), leaf area index (LAI) and leaf area duration (LAD) of three winter wheat varieties have been investigated on a chernozem soil. Three winter wheat varieties (GK Öthalom, Pannonikus and Genius) in three different nutrient-supply levels have been involved in our experiment in the crop-year of 2010/2011. The investigated physiological properties have been set against to the yield results. Upon the results of this comparison it has been stated that there is a close relationship between the investigated physiological properties and yield averages. The SPAD-values showed a growing tendency parallel to the growth of the nutrient-supply levels. The varieties have the highest SPAD-values at the nutri ent-level of N120+PK. Compared to the yield averages we have stated that varieties that have higher SPAD-values have realized higher yields as well. Higher nutrient dosages have increased in the leaf area. In case of all the three varieties the highest LAI-values were measured at the flowering stage (23. 05.) in the treatment whit N120+PK. Varieties with higher leaf area have produced higher yields as well. Parallel to the increasing nutrient-supply levels the value of leaf area duration increased as well. We measured the highest LAD-values in the treatment of N120+PK nutrient-level. By the LAD-values it can be stated that more durable and larger leaf area has been produced in the flowering and ripening phenophases, due to the higher nutrient-dosages. Analysing the relationships between the results it can be stated that there is a strong positive relationship between fertilizer treatments and SPAD-, LAI- and LAD-values. The genotype showed a strong positive correlation to SPAD-values. Yield averages showed strong positive correlation to SPAD-, LAI- and LAD-values as well.

  • Saccharomyces cerevisiae growth kinetics study dairy byproduct
    169-172
    Views:
    509

    By guess, annual volume of milk whey is 185–190 million tons and this volume probably will increase next years. Whey has significant biochemical oxygen demand due to its high organic matter content so whey as sewage is one of the most pollutant by-products in the food industry. Apart from environmental pollution, benefit of several whey constituents for human health is another reason to utilize whey. Corn and potato, as well as the processing of milk in the food industry in large quantities of by-products generated by low cost, substantial quantities of starch and lactic acid, which are due to high biological oxygen demand are considered as hazardous waste. Some of them are destroyed sewage storage tanks, and those products are excellent substrates for the growth of microorganisms could be. The traditional nutrient solution optimization methods are solution and time-consuming and are not able to determine the real optimum because of the interaction of factors involved.

  • Analysis of vitamin E content in pilot dairy products
    49-52
    Views:
    457

    Within the framework of Ányos Jedlik program we started an experiment on feeding anti-oxidants with dairy cows at Körös-Maros Biofarm Kft. The purpose of the experiment was to test whether vitamin E and selenium fed as feed-supplement have an effect on the composition of milk produced. Furthermore we examined the cheese and yoghurt made out of the milk to explore how much vitamin E and selenium is retained in the products after processing. Our goal is to develop such functional dairy product which can be part of the daily diet helping us to remain healthy.

    After analyzing the data we found out that the anti-oxidant fed to the cows resulted in elevated vitamin E and selenium levels in the milk and that these were retained in the cheese and yoghurt in relatively large amount.

  • Monitoring the oxygen level in the Szarvas-Kákafok Deadarm
    170-173
    Views:
    191

    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.

  • Investigation of the decomposition and leaching dynamics of Salix, Populus and mixed leaves in the area of Lake Balaton and Kis-Balaton Wetland
    119-124
    Views:
    365

    In lakes and wetlands, leaf litter input from the coastal vegetation represents a major nutrient load and plays a basic structural and functional role in several ecosystems. In Hungary, at the banks of lakes and wetlands, Salix and Populus trees are the most common species. In an experiment in Lake Balaton and Kis-Balaton Wetland between 16 November 2017 to and 3 June 2018, the decomposition rates and leaching dynamics of Salix, Populus and mixed leaves (50% Salix and 50% Populus) were investigated. Total nitrogen and phosphorus content of biomass samples were measured at the beginning and end of the experiment for the leaching dynamics experiment. We found that litter mass losses (Salix, Populus and mixed leaves) were not significantly different between the two mesh size litterbags and between Lake Balaton and Kis-Balaton Wetland. Different amounts of the total nitrogen and phosphorus leaching from Salix, Populus and mixed leaves were detected. The total nitrogen contents of the plant samples were around 8-18% at the end of the investigated period. Slightly higher values were measured compared to phosphorous (27-29%).

  • Growth regulators influence on stability of shoots and ascorbic acid content at cadmium and nickel joint action
    9-12
    Views:
    227

    It is shown that for a maize the most effective protector of cadmium and nickel influence was zeastimulin, for a pea – agrostimulin.A protective function of emistim C for both cultures was insignificant. It is set that zeastimulin is influential in the increased metals absorption of a root system, however substantially (on 15% for a nickel and twice for a cadmium) reduces their translocation to above-ground part of plants. Previous treatment of pea seed by agristimulin also intensified the accumulation of nickel roots on 60% and did not influence on cadmium absorption and toxicants translocation to tissues of assimilatory organs. The protector role of growth regulators to cadmium and nickel joint influence shows up in the increase of ascorbic acid maintenance in the roots cells of both species to 34%, where as in leaves – at a maize resulted in the lowering of vitamin С amount (on 28%), but at a pea – increase on 20%.

  • The effect of sowing date and plant density on the yield of maize (Zea mays L.) under different weather conditions
    205-208
    Views:
    634

    Maize has high productivity and produces huge vegetative and generative phytomass, but this crop is very sensitive to agroecological (mainly to climatic, partly to pedological conditions) and agrotechnical circumstances. In Hungary, maize is grown on 1.1–1.2 million hectares, the national average yields vary between 4–7 t ha-1 depending on the year and the intensity of production technology. The longterm experiment was set up in 2015–2016 on chernozem soil in the Hajdúság (eastern Hungary). The maize research was set up on chernozem soil at the Látókép MÉK (Faculty of Agricultural and Food Sciences and Environmental Management) research area of the University of Debrecen. We examined the following commonly used hybrids of Hungary: SY ARIOSO (FAO 300), P9074 (FAO 310), P9486 (FAO 360), SY Octavius (FAO 400), GK Kenéz (FAO 410), DKC 4943 (FAO 410). The experiment was set up in three different plant densities. These were 60, 76, 90 thousand plant ha-1. The experiment was set up with three different sowing dates, early, average and late sowing. The yield was measured using a special plot harvester (Sampo Rosenlew 2010), measuring the weight of the harvested plot and also taking a sample from it. As a next step, we calculated the yield (t ha-1) of each plot at 14% of moisture content to compare them to each other. We evaluated the obtained data using Microsoft Excel 2015.

  • The importance of chickpea (Cicer arietinum L.) and its cultivation in Hungary: A review
    71-75
    Views:
    256

    Climate change today is no longer a question for the future. Climate change impacts not only human populations but also plant species, which are increasingly exposed to its negative effects. The increasing number of days of drought, the lack of precipitation and its unfavorable distribution are observed each year, which require adaptation. Chickpea (Cicer arietinum L.) is a drought-tolerant species characterized by deep root system that enables it to withstand prolonged periods without precipitation. Additionally, it is a thermophilic crop and tolerates moderate increases in average temperature." There is no great tradition of its cultivation and use in Hungary, but it has been cultivated by the Iregszemcse Research Institute since the 1970s. In addition to the positive aspects of its cultivation, it also has good nutritional values, outperforming in some parameters the beans (Phaseolus vulgaris L.) and peas (Pisum sativum L.) what are popular in Hungary. Its high protein and crude fibre content allows it to be used not only for human consumption but also for animal feed. The aim of this review is to describe the importance of chickpea and to identify the advantages and disadvantages of its cultivation.

  • Genetic progress in winter wheat quality and quantity parameters
    71-75
    Views:
    404

    Wheat production is significant branch of Hungarian crop production (with about 1 million hectares of sowing area). Weather anomalies resulted by climate change have increased the importance of biological basis in wheat production. Yield quality and quantity parameters of three wheat genotypes sown on chernozem soil type after maize pre-crop were studied in a long-term field experiment. Yield amount of the studied genotypes varied between 2894 and 8074 kg ha-1 in 2017 and between 5795 and 9547 kg ha-1 in 2018 depending on the applied treatments. Based on our results it can be stated that in both studied crop years the highest yield increment was realized by the application of the nutrient supply level of N30+PK. As the result of the application of the optimum mineral fertilizer level – in contrast to the control – resulted in significant yield increment in both crop years. The results of the long-term field experiment prove that water utilization of the studied wheat varieties / hybrids was improved by the application of the optimal nutrient supply. Furthermore, the water utilization of the latest genotypes was more favorable by both the control and the optimum nutrient supply level treatments. Analyzing the quality parameters of winter wheat using the NIR method it has been stated that the quality results of the well-known genotype (GK Öthalom) were better than those of the new genotypes. A negative correlation between winter wheat quality and quantity parameters has also been confirmed. As the result of the mineral fertilizer application protein and gluten content of winter wheat increased to a significant extent.

  • Nutrient Uptake of Miscanthus in vitro Cultures
    23-24
    Views:
    251

    The large biomass production and the low necessary input fertilizer make Miscanthus an interesting, potential non-food crop with broad applications, e.g. for fuel and energy, for thatching, fiber production, for the paper and car industries, as well as for ethanol production.
    Axillary buds of Miscanthus x giganteus were placed on a shoot inducing nutrient solution (modified Murashige and Skoog, 1962), basic medium supplemented with 0,3 mg l-1 6-Benzylaminopurin. After 40 days of culturing, the axillary buds produced three times more shoots than could normally be harvested. The nutrient content (N, P, K, Ca, Mg) was measured several times during culturing. The results showed that, after 35 days, nitrogen and phosphate were nearly completely taken up. From that time, shoot growth was not observed.
    After shoot propagation, the plants were transfered into a nutrient solution for root formation (modified Murashige and Skoog, 1962), basic medium supplemented with 0,5 mg l-1 Indole- 3-Butyric acid, and could be potted in soil after about 14 days.

  • A study of the changes in management tasks
    39-44
    Views:
    198

    Determining the scope of management is difficult owing to the terminological uncertainty, which can be experienced often. The terms of management theory are interpreted differently not only by the general public but also by the highly recognised specialists, researchers, and instructors of this special area. The reasons for this can be found in historical preliminaries, the different social environment, attitude and approach. The definitions and the content of the terms have been modified and developed in parallel with the social and economic changes (Berde, 2001). The consequences of the economic changes of the past decade have significantly affected the conditions for the operation of management, the management structures, the ranking and importance of management tasks. The differentiating of corporate sizes, the increase in the number of small and medium-sized enterprises, the simplification of the production structure, the decrease in management levels, the strengthening of proprietary positions, and the continuous changing of the market economic environment are all influences that also affect, determine and continuously modify the management tasks.
    Everyone knows what a manager does. Still, it is not easy to determine what it does all day as his or her work is such a complex activity where the management tasks are present in a complex way, weaved into each other. Nevertheless, the separate management tasks appearing in the management activity can be defined well, can be separated from each other clearly, enabling us to study and analyse each management task separately.
    Based upon the findings of a face-to-face questionnaire survey, this essay aims to present that, according to the managers, to what extent the judgement of management tasks has changed and to what extent the applied management tasks specialise based upon the extent of relation to the company.

  • Food safety of plant origin food
    161-164
    Views:
    467

    Expectation regarding changes related to food production, transportation, distribution and marketing have changed considerably in several regions of the world over the past decades. It is especially true for highly industrialized countries where not only the food security is important but the food safety is essential too. The concentration of production – processing – distribution involves the danger on the one hand products of unsuitable quality from point of view of nutritional physiology and the other hand ones that may contain substances harmful to human health will become widespread among consumers. We investigated the heavy metal, pesticide remains and mycotoxin content of different plant products.

  • Physiological examination on cadmium sensitvity of some maize and sunflower varieties
    169-173
    Views:
    201

    Cadmium is one of the most dangerous heavy metals, which may cause serious problems in certain physiological processes of living organisms even in small amounts. In our work we analysed how cadmium affects some physiological parameters of different maize and sunflower hybrids. The chlorophyll contents and the morphological changes of the root were examined. We received different results in terms of the cadmium tolerance of these two plants.

  • Establishing regional cultivating districts on the basis of the Kreybig practical soil mapping system
    20-25
    Views:
    463

    With the help of this report evaluating the current situation of the region, characteristics of the development in agricultural production and regional differences can be clarified. By mapping out the regional soil, land use and climatic conditions and organizing these into a geographical information system, one can easily determine which plants are the most ideal to cultivate in that particular region. Moreover, it is a useful tool that enables us to
    establish the most favorable land use structure suited to ecological demands and also helps to determine the methods of soil protection.
    During our work, we chose administrative units in Szabolcs-Szatmár-Bereg County, based on the latest aspects of regional cultivation.
    Our pilot areas are: the small regions of Nyíregyháza, Nyírbátor, Nagykálló, Mátészalka and Csenger.
    Using the database, we separated and uncovered the soil conditions of the pilot areas: the chemical and physical properties of the soil layer which is exploited by the roots of the plants, the humus content, the nutrient supply, the thickness of the cultivated layer and the water management conditions.
    We separated the districts of regional cultivation, where the basic elements of the traditional Kreybig color systems were applied (light yellow, dark yellow, light brown, dark green, blue, pink, red, gray, greenish brown, reddish purple, light purple, dark purple, light green).
    By using the data collected from the pilot areas, we compiled a map database, which is suitable to illustrate the plant cultivating characteristics of the region. We made recommendations to determine the most favorable plants to cultivate in the specific region with the given meteorological and soil conditions, as well as for the shifting of crops.
    Our recommendations were also illustrated in a map with a resolution of 1:25000. 

  • The Effect of Changes in Forest Area on the Transcarpathian Tisza River Basin
    181-185
    Views:
    186

    Forests are unique global factors which ensure life for almost every living being on Earth. They play a major role in controlling water flows, preventing erosion and controlling the oxygen content of Earth’s atmosphere. By the end of the XXth century, it was realized that forests help to nature maintain and are vital parts of our natural environment. By the time societies realized this fact, economic and environmental effects had amplified which endanger forests. Due to their good water control and water protection abilities, and their function in climate control, mountain forests can provide a suitable environment for themselves, for their successful growth.
    Forests play a major role in soil protection, especially in mountain areas where they prevent soil erosion. By converting surface waters into subsurface waters, forests help with the accumulation of subsurface waters, which are the sources of springs, rivers and streams. In the summer, they protect the soil from drying out by creating a special microclimate. They positively affect the climate of surrounding territories.

  • The effects of curing technology on the rheological and organoleptic features of meat products
    139-142
    Views:
    191

    Meat products are important staple foodstuffs owing to their high protein, vitamin and mineral content. Meat plants do not only use traditional production technologies but also develop methods that preserve the nutritional value of meat or improve the texture and organoleptic features of meat products. These features play an important role in the consumer society. Consumers first meet the external features of meat and this experience influences their decisions. Our analyses compared a traditional and a new curing procedure. Besides organoleptic inspections, we analysed texture with a CT3 type Texture Analyser to obtain quantified information on the condition of meat samples in the various curing phases. We used our results to compare traditional and new curing procedures.

  • The Role of Cultivation Systems in Quality Sugar Beet Production
    134-138
    Views:
    609

    Producing sugar beet, as it is a demanding field crop, has contributed to the raising standard of plant production. It has an outstanding place among the plants that are cultivated in the intensive plant production system. Rentability of sugar manufacture is determined by the stability of yield and the quality (saccharose content) of sugar beet. In this way, the fundamental interest both of the producers and the processing industry is high yield and quality, year by year. The yield and the quality of the sugar beet are mainly determined by the plant production system, so we studied the effect of fertilization, irrigation and plant protection.

  • The examination of relation between the C/N ratio and the biogas yields in the Regional Biogas Plant of Nyírbátor
    63-68
    Views:
    278

    The Regional Biogas Plant of Nyírbátor was built by the Bátortrade Ltd. The biogas plant contains 6 mezophil and 6 thermophil fermentation tanks, because the biogas production is based on mixed compositions. The regional plant is a multifunctional system. It produces agricultural products and biogas with high methane content. The utilization of biogas is also accomplished here; gas-engines transform it to electricity and
    heat-energy. The product electricity is used by the local plants, the surplus is sold. 
    The aim of the research is the examination of the quality and quantity of the input materials that put into the mixers and follow the seasonal, periodical and optional changes of the input materials. The analyzation of the quality and quantity data can give an answer to the optional changes of biogas production because the input materials determine the composition of the examined recipe. The C/N ratio was between 11-13, the maximal value of the biogas yield was observed by 12.35 C/N ratio.

  • The effect of copper fungicides on the rate of photosynthesis and the transpiration of hop plants
    117-123
    Views:
    203

    The paper evaluates the effect of copper fungicide spraying on the rate of photosynthesis and transpiration of hops, the influence of spraying on the elemental copper content in the leaves and cones hop variety Agnus. Photosynthetic rate was measured by LC pro+ (infrared analyzer) in the Hop Research Institute Saaz in the field in some periods of 2008, 2009 and 2010. Dry cones and leaf samples (taken before and after application of copper fungicides) were analyzed in an accredited laboratory for elemental copper.

  • Study of factors controlling the amount of 0.01 M CaCl2 extractable Norg fraction
    437-449
    Views:
    332
    The use of new methods describing the “readily available” nutrient content of the soil is spreading on a global scale. The 0.01 M CaCl2 extractant is a dilute salt solution in which the easily soluble inorganic (nitrate-N and ammonium-N) and organic N fractions, P, K and micronutrients are also measurable. The 0.01 M CaCl2 has been tested in the University of Debrecen, Institute of Agricultural Chemistry and Soil Sciences since the 90’s. The results of the researches related to organic N fraction, performed in the last decades, and the results of the present study (originating from the long-term experiment of Karcag, 2007–2009) can be concluded as follows:
    The measurement of easily soluble and oxidizable organic nitrogen (Norg), besides inorganic fractions, could improve the nutrient management.
    The amount of the Norg fraction is determined by the soil conditions, therefore it is considered to be a site-specific parameter.
    Management practices and cropyear affect the amount of Norg as well. The present research confirmed that, the effect of fertilization on the amount of Norg can be explained by the changing of the yield (related to total biomass production), while the effect of cropyear is related to the differences in mineralization circumstances and yield as well.
    The measurement of the Norg fraction is increases the accuracy of N-supply, therefore it could prevent the environmentally harmful excess N application as well.
  • Preliminary results of the combined production of duckweed Spirodela polyrhiza and common carp (Cyprinus carpio) in an aquaponic system
    83-89
    Views:
    423

    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.

  • Determining elements of variety-specific maize production technology
    157-161
    Views:
    302

    Our aim was to work out such new maize fertilizer methods and models which can reduce the harmful effects of fertilization, can
    maintain the soil fertility and can moderate the yield fluctuation (nowadays 50-60 %).
    The soil of our experimental projects was meadow soil. The soil could be characterized by high clay content and pour phosphorus and
    medium potassium contents. In the last decade, out of ten years six years were dry and hot in our region. So the importance of crop-rotation
    is increasing and we have to strive for using the appropriate crop rotation.
    The yields of maize in monoculture crop rotation decreased by 1-3 t ha-1 in each dry year during the experiment (1983, 1990, 1992,
    1993, 1994, 1995, 1998, 2000, 2003, and 2007). The most favourable forecrop of maize was wheat, medium was the biculture crop rotation
    and the worst crop rotation was the monoculture.
    There is a strong correlation between the sowing time and the yield of maize hybrids, but this interactive effect can be modified by the
    amount and distribution of precipitation in the vegetation period. At the early sowing time, the grain moistures were 5-12 % lower compared
    to the late sowing time and 4-5 % lower compared to the optimum sowing treatment.
    There are great differences among the plant density of different maize hybrids. There are hybrids sensitive to higher plant density and
    there are hybrids with wide and narrow optimum plant densities.
    The agro-ecological optimum fertilizer dosage of hybrids with a longer season (FAO 400-500) was N 30-40 kg ha-1 higher in favourable
    years as compared to early hybrids.
    We can summarize our results by saying that we have to use hybrid-specific technologies in maize production. In the future, we have to
    increase the level of inputs and have to apply the best appropriate hybrids and with respect to the agroecologial conditions, we can better
    utilize the genetic yield potential.