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  • The Evaluation of Grazed Grasslands on the Hortobágy
    50-54
    Views:
    111

    The sward composition of different grasslands on Puszta Hortobágy has been developed according to prevailing abiotic and biotic factors. The abiotic conditions have been more or less constans for long periods of time, and the abiotic factors are determined by ecological conditions (climate, soil, topography). Among biotic factors grazing of herbivores was important in the development of Hortobágy grasslands for centuries (Sipos and Varga, 1993). Result of three-year investigations on the sward composition of grasslands utilised in different ways are presented. Data on ground cover, number of plant species, representation of different plant groups (grasses, sedge and bent-grass, herbs, legumes) and weeds are reported from six different grazed grassland types from Puszta Hortobágy.
    In 1999-2001 a sward composition survey was conducted. Sample areas of 2x2 m2 were marked out in three replicates: on temporarily waterlogged grassland grazed by cattle (A), on dry grassland grazed by cattle (B), on dry grassland grazed by sheep (C), on dry grassland grazed by buffaloes (D), on dry grassland grazed by buffaloes and geese (E), on dry grassland cut for hay in May then grazed by geese (F). On the sample areas sward composition of grasslands was estimated according to Balázs (1949).
    The average ground cover of different grasslands ranged between 60 and 100% (Table 2). The lowest value was found for grasslands C and E, which are grazed by sheep (C) and buffaloes and geese alternately (E). In these grasslands were some open spaces, on the other grasslands completely closed swards covers were observed.
    The species diversity of these natural grasslands are high (Table 2). The grassland F, which were cut for hay in May had the lowest diversity (17-21). The highest number of species was found on grassland A and B (32-51), on other grazed grasslands (C, D, E) had 29-48 species.
    The different plant groups had different representation in the total ground cover (Table 3). The number of herbs was always higher then that of grasses, but the cover of herbs was lower then that of grasses. The legumes and the sedge and bent grasses were present in high abundance in grassland A, but in the other grasslands were not.
    The composition of herbs should be a warning for future utilisation systems on some grasslands of Hortobágy. Some species of herbs, e.g. Achillea millefolium, Artemisia vulgaris, Carduus acanthoides, Cirsium arvense, Cirsium vulgare Eryngium campestre, Galium mollugo, Galium verum, Ononis spinosa, Rumex crispus, Verbascum phlomoideus, Phragmites australis can be invasive on short grasslands.

  • Technological development of sustainable maize production
    83-88
    Views:
    144

    In our research we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize.
    The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly eight ha field. The size of one plot was 206 m2, this it was a half-industrial experiment. We tested six hybrids with different genetic characteristics and growing seasons. I analysed the correlation between the nutrient supply and the yield of maize hybrids with control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. Yield increasing effect of the fertilizer also depended on the number of plants per hectare at a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants per ha.
    In Hajdúszoboszló, in 2016 the amount of rainfall from January to October was 605 mm, which was more than the average of 30 years by 160 mm. The yield of hybrids without fertilization changed between 9.63–11.6 t ha-1 depending on the number of plants.
    The six tested hybrids is 10.65 t ha-1 in the average of the stand density of 60, 70 and 80 thousand plants per hectare without fertilization, while it is 12.24 t ha-1 with N80+PK fertilizer treatment. That increase in the yield is 1.6 t ha-1, it is significant.
    Da Sonka hybrid is sensitive to weather, it is able to produce 6 t ha-1 additional yield in case of favourable condition. However, it has a low stress tolerance. The most stable yields were observed at Kamaria and Pioneer hybrids. The effect of vintage is also an important factor on the yield. In average, the yield of maize was 6.81 t ha-1 in 2015, which was a drought year and 11.86 t ha-1 in 2016 that was a favourable year.

  • Assessment of Environmental Susceptibility/Vulnerability of Soils
    62-74
    Views:
    86

    Soils represent a considerable part of the natural resources of Hungary. Consequently, rational land use and proper soil management – to guarantee normal soil functions – are important elements of sustainable (agricultural) development, having special importance both in the national economy and in environment protection.
    The main soil functions in the biosphere are as follows: conditionally renewable natural resource; reactor, transformer and integrator of the combined influences of other natural resources (solar radiation, atmosphere, surface and subsurface waters, biological resources), place of „sphere-interactions”; medium for biomass production, primary food-source of the biosphere; storage of heat, water and plant nutrients; natural filter and detoxication system, which may prevent the deeper geological formations and the subsurface waters from various pollutants; high capacity buffer medium, which may prevent or moderate the unfavourable consequences of various environmental stresses; significant gene-reservoir, an important element of biodiversity.
    Society utilizes these functions in different ways (rate, method, efficiency) throughout history, depending on the given natural conditions and socio-economic circumstances. In many cases the character of the particular functions was not properly taken into consideration during the utilization of soil resources, and the misguided management resulted in their over-exploitation, decreasing efficiency of one or more soil functions, and – over a certain limit – serious environmental deterioration.
    Soil resources are threatened by the following environmental stresses:
    – soil degradation processes;
    – extreme moisture regime;
    – nutrient stresses (deficiency or toxicity);
    – environmental pollution.
    Environmental stresses caused by natural factors or human activities represent an increasing ecological threat to the biosphere, as well as a socio-economic risk for sustainable development, including rational land use and soil management.
    The stresses are caused by the integrated impacts of various soil properties, which are the results of soil processes (mass and energy regimes, abiotic and biotic transport and transformation and their interactions) under the combined influences of soil forming factors. Consequently, the control of soil processes is a great challenge and the main task of soil science and soil management in sustainable development.
    The efficient control of these processes necessitates the following consecutive steps:
    • registration of facts and consequences (information on land and soil characteristics, land use, cropping pattern, applied agrotechnics, yields, with their spatial and temporal variability);
    • evaluation of potential reasons (definition and quantification of soil processes, analysis of influencing factors and their mechanisms);
    • assessment of the theoretical, real, rational and economic possibilities for the control of soil processes (including their risk-assessment and impact analysis);
    • elaboration of efficient technologies for the „best” control alternatives (best management practice).
    Scientifically based planning and implementation of sustainable land use and rational soil management to ensure desirable soil functions, without any undesirable environmental side-effects, require adequate soil information. In the last years such data were organized into a computer-based GIS soil database in Hungary, giving opportunities for the quantification, analysis, modelling and forecasting of the studied environmental stresses and for the efficient and scientifically based prevention, elimination or reduction of environmental stresses and their unfavourable ecological and economical consequences.
    Special attention was paid to the assessment of various soil degradation processes, as: (1) soil erosion by water or wind; (2) soil acidification; (3) salinization and/or alkalization; (4) physical degradation (structure destruction, compaction); (5) extreme moisture regime: drought sensitivity and waterlogging hazard; (6) biological degradation; (7) unfavourable changes in the plant nutrient regime; (8) decrease of natural buffering capacity, (9) soil (and water) pollution.
    The actions against undesirable environmental stresses and their unfavourable consequences are important elements of sustainable, efficient, economically viable, socially acceptable and environmentally sound crop production and agricultural development. These are joint tasks of the state, decision makers on various levels, the land owners, the land users and – to a certain extent – of each member of the society.

  • The effect of and interaction between the biological bases and the agrotechnical factors on maize yield
    83-87
    Views:
    144
    The effect of and interaction between the biological bases and the agrotechnical factors on maize yield In our research, we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize. The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2; therefore, this experiment was half-industrial. We tested six hybrids with different genetic characteristics and growing seasons.
    We analysed the correlation between the nutrient supply and the yield of maize hybrids with a control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. The yield increasing effect of the fertilizer also depended on the number of plants per hectare to a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants ha-1.
    In 2015, the highest yield was produced by hybrid P9241 with N80+PK and 70 thousand plants per hectare. With the N160+PK fertilizer dosage, the same hybrid responded the best, followed by hybrids P9486 and DKC4717. Using the same fertilizer treatment, the 80 thousand plants per hectare population density resulted in decrease in the yield with most of the examined hybrids. In 2016, with the increase in the number of plants per hectare, even with non-fertilised treatment (control treatment), the yield could be increased in the case of each hybrid.
    Averaged over the different hybrids and fertilizer treatments, applying 80 thousand plants ha-1 instead of 60 thousand resulted in 1.0 ha-1 yield increase. In 2017, the number of plants had a slighter effect. With N160+PK treatment, in most cases no significant difference can be observed. The value of LSD5%: plant number: 0.20 t ha-1, hybrid: 0.28 t ha-1, interaction: 0.48 t ha-1. With N160+PK treatment, the hybrids produced yields between 10.07 and 12.45 t ha-1. When examining the three years in the average of the number of plants, with treatment without fertilisation, the average yield of hybrids reached 7.53 t ha-1. With N80+PK treatment, this value was 9.71 t ha-1 and with doubling the fertilizer dosage, this value increased to 10.42 t ha-1. No economic profit was gained as a result of applying double dosage of fertilizer; therefore, the N80+PK dosage can be considered ideal.
  • Correlation between the weather in 2017 and the productivity of maize
    89-93
    Views:
    152
    In our research we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize. The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2; therefore, this experiment was half-industrial. We tested six hybrids with different genetic characteristics and growing seasons. I analysed the correlation between the nutrient supply and the yield of maize hybrids with control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. The yield increasing effect of the fertilizer also depended on the number of plants per hectare to a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants ha-1.
    In Hajdúszoboszló in 2017, up to October, 445.8 mm of rain fell, which is in line with the average values of 30 years, and is only 45.7 mm less than those. In 2017, the effect of increasing the plant number was slighter. Averaged over the observed fertilizer treatments and hybrids, the yield was 9.10 t ha-1 with 60 thousand plants ha-1, 9.11 t ha-1 with 70 thousand plants ha-1 and 9.12 t ha-1 with 80 thousand plants ha-1. Without fertilization, in most cases, increasing the plant number from 60 thousand plants ha-1 to 70-80 thousand plants ha-1 does not increased the yield but decreased it. With N80+PK treatment the yield changed between 8.90 and 11.27 t ha-1. The effect of increasing the plant number was just slightly observable and did not show a clear tendency. The effect of changing the plant number, even with the highest dosage of fertilizers, could not be detected adequately. In contrast with the plant number, the effect of the different fertilizer treatments was expressly traceable. Compared to the control treatment (treatment without fertilization), with N80+PK fertilizer dosage with 60 thousand plants ha-1 the yield increased by 3.36–4.99 t ha-1. The smallest demonstrable proof, i.e. the LSD5% was 0.22 t ha-1, which means that fertilization, in each case, significantly increased the yield. When analysing the effect of fertilization in the average of the hybrids and the different plant numbers, a yield of 5.61 t ha-1 could be detected, which value was 10.12 t ha-1 with N80+PK treatment and 11.61 t ha-1 with N160+PK treatment. Thus, it can be calculated that compared to the treatment without fertilization, the N80+PK treatment increased the yield by 4.51 t ha-1, while compared to the N80+PK treatment, the N160+PK treatment increased the yield by 1.49 t ha-1. In addition to agrotechnical factors, in maize production, the impact of the crop year is specifically of high importance.
    The average yield of hybrids (in the average of the different fertilizer treatments) was 6.81 t ha-1 in 2015, 11.86 t ha-1 in 2016 and 9.11 t ha-1 in 2017. When comparing the yield results against the precipitation data, it is clearly visible that the amount of rain fell in the January– October period is directly proportional to the average yield of maize. The effect of the crop year can be defined in a 5.05 t ha-1 difference in the yield.
  • Effect of divided nitrogen and sulfur fertilization on the quality of winter wheat
    27-31
    Views:
    158

    The ecological characteristics and agro-ecological conditions in Hungary provide opportunities for quality wheat production. For the successful wheat production besides the favorable conditions; the proper use of expertise and appropriate cultivation techniques are not negligible. Successful cultivation affected by many factors. To some extent we can affect, influence and convert the abiotic factors.

    Today, a particularly topical issue is the question of nutrition and that the species’ genetic code can be validated using the appropriate quantity and quality fertilizer. Beyond determining the fertilizer requirements of the winter wheat it is important to align the nutrient to the plant’s nutrient uptake dynamics and to ensure its shared dispensing. In any case, it is important to note the use of autumnal base-fertilizer as complex fertilizer. Hereafter sharing the fertilizer during the growing season with the recommended adequate nitrogen dose.The first top dressing of winter wheat in early spring (the time of tillering) can be made, the second top dressing at the time of stem elongation, and the third top dressing at the end of the blooming can be justified. Determining the rate of fertilizer application depends on the habitat conditions and the specific nutrient needs of plants. In autumn the 1/3 of the planned amount of basic fertilizer should be dispensed (in case of N). During setting our experiment we used 3 doses (0 kg ha-1 N-1 active ingredient; 90 kg ha-1 N-1 active ingredients and 150 kg ha-1 N-1 active ingredient). Application dates beyond the autumn basic fertilization are the following: in one pass in early spring, divided in early spring and the time of run up, early spring and late flowering. In addition to nitrogen the replacement of sulfur gets a prominent role as a result of decreased atmospheric inputs. The proper sulfur supply mainly affects the quality parameters. It influences positively the wheat flour’s measure of value characteristics (gluten properties, volume of bread, dough rheology.

    In terms of nitrogen doses; the larger amounts (150 kg ha-1 N-1 drug), is the proposed distributed application, while in the case of lower nitrogen (90 kg ha-1 N-1 drug) in a single pass in the early spring can achieve better results. After using sulfur the quality values among the nutritional parameters that can be associated with gluten properties took up higher values than the samples not treated with sulfur.

  • Screening of paprika (Capsicum annuum L.) varieties resistant to NaCl salt stress
    105-110
    Views:
    112

    Salinity stress is one of the environmental factors that negatively affect the growth and production of pepper plants. The 100 seeds' weight was measured. The total fresh weight of five seedlings and the growth rate of one seedling of three paprika varieties were also measured under the influence of NaCl at a salinity level threshold of (3 dS m‑1). The proportion of tissue water content in three pepper cultivars was measured according to a mathematical formula at the end of the experiment. In terms of seed weight, the (Carma) cultivar outperformed other types greatly. Except for the superiority of both (Carma, and Bobita F1) over (Fokusz) variety in total fresh seedlings weight under sodium chloride as abiotic stress, there are no significant differences in the total seedlings' dry weight and the rate of seedling growth. The non-drought-resistant type (Bobita F1) loses water the fastest, at 89.61%, compared to drought-tolerant kinds, which lose water at a slower rate (Carma, and Fokusz). The results demonstrate the (Carma) variety's numerical vigor, particularly in the growth rate. More testing is needed to determine the selection of varieties that are resistant to abiotic and biotic stresses.

  • The effects of drought stress on soybean (Glycine max (L.) Merr.) growth, physiology and quality – Review
    19-24
    Views:
    188

    Abiotic stresses are one of the most limiting factors inhibit plant's growth, leading to a serious production loss. Drought stress is one of the most destructive abiotic stresses and is still increasing year after year resulting in serious yield losses in many regions of the world,
    consequently, affecting world’s food security for the increasing world population. Soybean is an important grain legume. It is one of the five major crops in the world, an essential source of oil, protein, macronutrients and minerals, and it is known as the main source of plant oil and protein. Harvested area of soybean is increasing globally year after year. However, soybean is the highest drought stress sensitive crop, the water deficit influences the physiology, production and seed composition of this crop. We introduce a review for literatures concerning the changes of the above traits of soybean exposed to drought stress, with past explanations for these changes.

  • Integrated nutrient supply and varietal difference influence grain yield and yield related physio-morphological traits of durum wheat (Triticum turgidum L.) varieties under drought condition
    111-121
    Views:
    107

    The ever-growing world population entails an improvement in durum wheat grain yield to ensure an adequate food supply, which often gets impaired by several biotic and abiotic factors. Integrated nutrient management, such as nitrogen rate × foliar zinc × sulphur fertilization combined with durum wheat varieties were investigated in order to examine the dynamics of yield and yield related physio-morphological traits under drought conditions. The four durum wheat varieties, three-level of nutrient supply (i.e. control, sulphur, and zinc), and two nitrogen regimes (i.e. zero and 60 kg ha−1) were arranged in split-split plot design with three replications. Zinc and sulphur were applied as foliar fertilisation during the flag leaf stage, both at a rate of 3 and 4 liters ha-1, respectively. Results showed existence of genetic variability for grain yield, plant height, NDVI, SPAD and spike density. Foliar based application of zinc and sulphur at the latter stage improved the plant height. Nitrogen fertilized varieties with lower spike numbers showed to better yield formation. Co-fertilization of nitrogen and zinc improved grain yield of responsive varieties like Duragold by about 21.3%. Spikes per m2 were statistically insignificant for grain yield improvement. It could be inferred that the observed positive effect of sulphur, nitrogen and zinc application on physio-morphology and yield formation substantiates the need to include these essential nutrients in the cultivation system of durum wheat.

  • Challenges – the impact of climate change on the nutritional management of Hungarian orchards
    323-334
    Views:
    212

    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.

  • The effect of NPK fertilization and the number of plants on the yield of maize hybrids with different genetic base in half-industrial experiment
    103-108
    Views:
    178

    In our research we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize.

    The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2, this it was a halfindustrial experiment. We tested six hybrids with different genetic characteristics and growing seasons. I analysed the correlation between the nutrient supply and the yield of maize hybrids with control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. Yield increasing effect of the fertilizer also depended on the number of plants per hectare at a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants/ha.

    In Hajdúszoboszló, in 2015 the amount of rainfall from January to October was 340.3 mm, which was less than the average of 30 years by 105.5 mm. This year was not only draughty but it was also extremely hot, as the average temperature was higher by 1.7 °C than the average of 30 years. In the critical months of the growing season the distribution of precipitation was unfavourable for maize: in June the amount of rainfall was less by 31mm and in July by 42 mm than the average of many years.

    Unfavourable effects of the weather of year 2015 were reflected also by our experimental data. The yield of hybrids without fertilization changed between 5.28–7.13 t ha-1 depending on the number of plants.

    It can be associated also with the unfavourable crop year that the yield of the six tested hybrids is 6.33 t ha-1 in the average of the stand density of 60, 70 and 80 thousand plants per hectare without fertilization, while it is 7.14 t ha-1 with N80+PK fertilizer treatment. That increase in the yield is only 0.81 t ha-1, but it is significant. Due to the especially draughty weather the yield increasing effect of fertilizers was moderate. In the average of the hybrids and the number of plants, increasing the N80+PK treatment to N160+PK, the yield did not increase but decreased, which is explicable by the water scarcity in the period of flowering, fertilization and grain filling.

    The agroecological optimum of fertilization was N 80, P2O5 60 and K2O 70 kg ha-1. Due to the intense water scarcity, increased fertilization caused decrease in the yield. As for the number of plants, 70 000 plants ha-1 proved to be the optimum, and the further increase of the number of plants caused decrease in the yield.

  • Heavy Metals in Agricultural Soils
    85-89
    Views:
    69

    The soil constitutes the basis of the food chain. To keep soil conditions in a good trim is very important, it’s part of the sustainable development and of producing food supply harmless to health.
    In some cases, soil productivity is the only important part, qualitative requirements or economical characteristics can improve it. The soil is threatened by two danger factors: the soil degradation and the soil pollution. The accumulation of different harmful and/or toxic substances in the soil is well known. Heavy metals constitute a part of it. Metals in the soil and in the soil-solution are balanced. This balance depends on the type of the metal, on the pH, on the cation-band capacity of the soil, on the redox relations and the concentration of cations in the soil.
    To be able to handle the metal contamination of the soil, it is important to estimate the form, the possible extension and the concentration of metals.
    Of course, the different types of soils have different physical-chemical, biological and buffer capacity, they can moderate or reinforce the harmful effects of heavy metals. To draw general conclusion of the dispersion and quantitative relations on the metals originated from different contamination sources is hard, because in some emissive sources contamination is limited in small areas but on a high level, some others usually expand on larger areas, and as a result of equal dispersion, the contamination’s level is lower.
    Heavy metals – unlike alkali ions – strongly bond to organic materials, or infiltrate in a kelát form. Their outstanding characteristic is the tendency to create metal-complex forms. Kelats take part in the uptaking and transportation of heavy metals. Heavy metals exert their effects mostly as enzyme-activators.
    The metals cannot degrade in an organic way, they accumulate in living organisms, and they can form toxic compounds through biochemical reactions.
    Lot of the heavy metals accumulate on the boundaries of the abiotic systems (air/soil, water/sediment), when physical or chemical parameters change, and this influences their remobilization.
    Human activity plays a great part in heavy metal mobilization, results in the human origin of most biochemical process of metals.
    To understand the toxic influence of accumulated metals of high concentration, their transportation from soils to plants or their damage in human health, must clearly defined and investigated.
    For effective protection against soil pollution, the types and levels of harmful pollution to soil must identified, regarding legal, technical and soil-science aspects, preferable in a single way. Difficulties in this area mean that toxicity depends on loading, uptake, soil characteristics and living organisms (species, age, condition etc.), furthermore, local and economic conditions considerably differ.

  • Impact of environmental changes resulting from different sowing dates on maize yield
    99-104
    Views:
    132

    Three Debrecen maize hybrids of different genotypes (Debreceni 285, Debreceni 377 and Debreceni 382) were examined on chernozem soil in a field experiment. During the two years of the experiment (2009–2010), we wanted to get to know how the examined hybrids reach to different sowing dates and what impact early, optimal and late sowing has on yield.

    In 2009, balanced soil and air temperature resulted in steady emergence. However, the low temperature in early April and the cooling down in mid-May 2010 caused a delayed emergence.

    The grain moisture content at harvesting and the high yield showed a strong crop year effect. In 2010, yield was much lower (1.664 t ha-1) and grain moisture was significantly higher (34%)than in 2009.

    In 2009, early sowing resulted in yield decrease (P<0.05), but it also significantly reduced grain moisture at harvesting (P<0.05). Although late sowing slightly increased yield (not significantly), but grain moisture at harvesting increased by 9.2%. In 2010, optimal sowing date was shown to be the best alternative from the aspect of yield, but there was no significant difference in comparison with early and late sowing. Grain moisture at harvesting greatly increased (13.3%).

    The Debreceni 382 maize hybrid reacted to sowing dates flexibly, neither early, nor late sowing affected its yield significantly and the grain moisture at harvesting showed 12% increase in the case of the late sowing date. In 2009, maize hybrids Debreceni 285 and Debreceni 377 reached their highest yield in the case of the sowing date which was shown to be optimal (23rd April), while the different sowing dates had no effect on yield in 2010.