Search
Search Results
-
Comparison of the physiological responses of an oil-pumpkin cultivar and hybrid under different nitrogen supply conditions
65-69Views:420Cucurbita pepo var. styriaca is known as a medicinal crop among other cucurbits. The benefits of cucurbits fruits are very important in terms of human health, purification of blood, removal of constipation, digestion and supplying energy. The mutant styrian oil-pumpkin (Cucurbita pepo L. convar. Pepo var. styriaca Greb.) exposes a complete lack of lignification of the seed testa. For this reason, this kind of naked pumpkin seed is more consumable as snack than other seeds. The vegetative growth of plants is crucial for fruit production. Nitrogen is the most imperative element for the proper vegetative growth and development of plants which significantly increases and enhances yield and its quality by playing a vital role in the biochemical and physiological functions of plants.
Field studies were conducted to study the effect of nitrogen nutrition on certain physiological parameters and their differences between the styrian oil pumpkin hybrid and cultivar (Gleisdorfi Classic cultivar and GL Rustical hybrid). The small block experiment was carried out based on a factorial experiment with a completely randomised block design and four replications in the Research Institute of Nyíregyháza during the summer period of 2017 and 2018. Three different concentrations of nitrogen fertiliser was applied at sowing. Photosynthetic pigments (chlorophyll-a, -b and carotenoids) were analysed as one of the basic factor of efficient photosynthesis. The yields of two genotypes were also measured in all treatments as seed-weight. The contents of photosynthetic pigments were higher in the oil-pumpkin hybrid, mainly the carotenoids in 2018. The vegetation period of 2018 was drier than in 2017, the hybrid oil-pupmkin was more efficient in stress tolerance than the cultivar with higher carotenoids pool. The obtained yield was more pronounced in the oil-pumpkin hybrid than the cultivar in all examined years. The hybrid GL Rustical was more sensitive to nitrogen treatment than the cultivar Gleisdorfi Classic.
-
Changes in the Macro-, Mezo-, and Microelement Contents of Maize Hybrids in Relation to the Level of Nutrient Supply
126-130Views:145n my research, I measured the effect of NPK fertilisation on the macro- meso- and microelements content of maize hybrids in 2001. The experiment was set in the demonstration garden of the Department of Crop Production and Applied Ecology in the Agricultural Centre, at the University in Debrecen. The soil of the experiment is calcerous chernozem soil. Five fertilisation steps were applied. Besides the control the smallest rate was 40 kg N; 25 kg P2O5; 30 kg K2O of active ingredients. The largest rate was five times more than the smallest one: 200 kg N; 125 kg P2O5; 150 kg K2O, which is equal to 475 kg mixed active ingredients. The NPK treatment significantly influenced the macrolement content in several cases. The N content was the lowest in the control treatment. Compared to this the fertiliser treatments significantly increased the N content of hybrids. However the highest amounts of potassium and phosphorus could be measured in the control and the lowest amounts could be measured at the N 200+PK kg/ha treatment.
The Ca content of hybrids was the highest in the N 120+PK kg/ha treatment, while their Mg and Zn content was the highest in the control treatment. The lowest amounts were weighed in the N 200+PK kg/ha treatments, that in several cases resulted in statistically proved decreasement compared to the control or the lower fertilizer doses. Considering the two mesoelements and Zn the most favourable results were obtained in the case of the Norma SC and DK 366 SC hybrids.
Summing up what has been said moderate amounts of fertiliser doses (N 40-120+PK kg/ha) had a favourable influence on the micro- and macroelement content of hybrids. -
Grain Moisture of Maize Hybrids in Different Maturity Groups at Various Harvesting Dates
24-25Views:185The experiments were designed to determine the extent to which late harvesting helped to achieve low grain moisture content. The grain moisture contents of 24 hybrids from each of four different maturity groups were recorded during the last decade of September and the first decade of November over a period of three years (1999-2001).
The data indicated that late harvesting led to a substantially smaller difference between the hybrids. While in late September the difference between the grain moisture content of the earliest (FAO 200) and latest (FAO 500) hybrids was 8.9%, this value dropped to 1.5% over the average of three years when measurements were made in early November. With the exception of the earliest group, the grain moisture content in all the maturity groups declined during October. The later the hybrid, the greater the decline.
This change in the grain moisture content during October exhibited a considerable year effect. When the weather in October was warm, with little rain, the decrease was greater, while in cool, wet years the grain moisture content declined to a lesser extent, or in some cases even increased. -
The Role of Cultivation Systems in Quality Sugar Beet Production
134-138Views:371Producing 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 response of sunflower hybrids to different plant densities on a chernozem soil
123-128Views:452In our experiment the reaction of six sunflower hybrids of different genotypes (NK Oktava, ES Biba, ES Diagora, ES Ballistic, EGH 8925, PR 64 H 42) towards plant density has been investigated by different fungicide treatments in the crop-year of 2011 on a chernozem soil.
In the crop-year of 2011 sunflower populations were infected by a significant Diaporthe helianthi disease. The extent of this infection was significantly enhanced by the increment of plant density. However, regarding the average of the hybrids and plant densities the two times executed fungicide treatment has decreased the infection rate by 22%. The most susceptible hybrid was the ES Biba. Contrarily, the hybrid ECH8925 proved to be the most resistant hybrid towards this
disease according to our results. According to the results of the Pearson’s correlation analysis it has been revealed that stalk breakage and Diaporthe infection stand in a very close (r=0.782**) and middle close (r=0.523**) correlation resp. with plant density. The relationship between fungucude treatments and stalk breakage, just as Diaporthe infection showed to be middle and close respectively. Our results demonstrate the role of stalk and plate diseases (among them Diaporthe) in causing stalk breakage, for we have found a close positive correlation between stalk breakage and Diaporthe infection (r=0.624**) in our analysis.
From the aspect of yield amount the optimal plant density varied between 45 000 and 55 000 plants per hectare. Fungucude treatments enabled not only the use of higher plants densities, but they had a yield increasing effect as well. In the crop-year of 2011 the highest yield (4 559 kg ha-1) on a chernozem soil has been measured in case of the hybrid ECH8925. -
Anthropogenic effects on the fish fauna of River Hernád
21-27Views:265The fish fauna of the River Hernád was examined in 24 sampling sites in summer of 2014. As a result of the survey 31 species were detected of which eight are protected and three are highly protected by law in Hungary. The presence of the adventive tubenose goby (Proterorhinus semilunaris) in the estuary of the Hernád was observed for the first time by us. The most frequently detected species (with 100% frequency of occurrence, FO) were the chub (Squaliuscephalus), the bitterling (Rhodeusamarus) and the bleak (Alburnusalburnus), in addition the bleak was also the most dominant fish of the river. The hydraulic works have detrimental effect on the number of species and specimens and on the diversity of the fish fauna as well. The natural sections of the River Hernád have the most diverse fish assemblages.
-
Investigation of soils of stubbles of winter wheat and winter peas in conventional and reduced tillage systems
95-99Views:314The effect of reduced and conventional tillage on soil compaction, soil moisture status and carbon-dioxide emission of the soil was studied on a meadow chernozem soil with high clay content in the soil cultivation experiment started in 1997 at Karcag Research Institute. Our investigations were done on stubbles after the harvest of winter wheat and winter peas after the very droughty vegetation period of 2014/2015.
We established that the soil in both tillage systems was dry and compacted and the CO2-emission was very low. The positive effects of reduced tillage could be figured out only in the soil layer of 40–60 cm in the given weather conditions of that period.
-
The use of Common duckweed (Lemna minor) as a biological filter in the rearing of hybrid African catfish (Clarias gariepinus x Heterobranchus longifilis)
107-112Views:488The African catfish (Clarias gariepinus x Heterobranchus longifilis) is one of the most important fish species in Hungarian aquaculture. The larvae and juveniles are reared at high feeding rates, which can reach up to 10% of the biomass. Intensive feeding results in large amounts of effluent water, directly proportional to the intensity of fish production. The aim of this experiment was to investigate the potential of Common duckweed (Lemna minor) as a biological filter and its nutrient removal capacity during intensive fry rearing of the hybrid African catfish. In a recent study, two experimental recirculation systems, identical in water volume and design, were set up, in one of which duckweed was grown under aquaponic conditions, where the concentrations of nitrogen and phosphorus forms were monitored and the production parameters of the fish were determined. The results obtained from the experiment showed that the use of duckweed as a biological filter improves the water quality of the recirculation system. A significant amount of plant biomass was produced, which mainly reduced the nitrate and orthophosphate concentrations in the system water. As a consequence, the survival of hybrid catfish was improved, which also affected biomass growth, but had no effect on other parameters.
-
Economics of site specific crop density in precision sunflower (Helianthus annuus L.) production
91-96Views:371In this research, the crop density of sunflower was examined, which, thanks to the tools available for precision crop production and knowledge of the market environment of sunflower production, best fits the heterogeneous areas of the given production zones and meets the economic requirements. These components together directly influence the effectiveness of sunflower production. In the year of 2021 and 2022, we carried out a site-specific crop density sunflower experiment in two fields with the same soil type, by sowing significantly different amounts of seeds within the given zones. We have established that the sunflower, although a plant with excellent adaptability, reacts sensitively to the place of production and the effect of the year, in zones with heterogeneous productivity, and shows a reaction to sowing with a variable number of seeds per zone, even when examined based on economic aspects.
-
Previous data on the relationship between the intensity of pruning and the degree of damage in integrated and organic applegrowing systems
47-52Views:223In Hungary, fruit growers are increasingly interested in environmentally friendly growing methods, such as organic and integrated systems. Vital is the establishment of a strengthened system of cultivar-pruning-plant protection in production technology. Consequently, our aim was to examine the susceptibility of apple cultivars to diseases and pests and the effect of pruning technique on diseases and pests in organic and integrated growing systems.
Two pathogens (Venturia inaequalis, Podosphaera leucotricha) and two pests (Leucoptera malifoliella, Pannonychus ulmi) were observed in organic and integrated systems under „strong” and „weak” pruning techniques. Our results on six cultivars showed that the pathogens and pests infested the trees more in the organic system, as compared to that of integrated production. The pruning technique affected mainly the susceptible
cultivars to diseases and pests. The „weak” pruning technique caused a higher level of diseases and pests infestations than the „strong” pruning technique, especially in the organic growing system. The likely reason is that the shoots grow fast and powerfully under “strong” pruning technique. This supports better preservation of the trees supported by susceptibility of plant tissues to diseases and pests. -
The Effect of Sowing Time and Nutrient Supply on the Yield Stability of Maize
75-80Views:297Sowing time, nutrient supply and plant number play crucial roles in the yield stability of maize. The productivity of various hybrids, each with its own genetic characteristics, was tested for three different sowing times and five different fertilizer doses. The highest yields were achieved at the third sowing time (17. V.), which is unusual, because the second half of the summer was rainy and was favourable for late sowing. The seed moisture content at harvest was higher than the optimal 14-15% at the third sowing time, the hybrids, which have intensive bleeding dynamics, couldn’t reach the lower seed moisture content at harvest of the early sowing. In that case we have to decision whether the plus yield of the third sowing time cover the drying costs.
Some hybrids produced the highest yields by N 120, P2O5 75, K2O 90 kg/ha active agent but the higher fertilizer doses depress the yield. The other part of the hybrids were able to produce high yield by bigger fertilizer doses. On the whole the agro-ecological optimum of the NPK fertilization was N 120-160, P 25-100, K 90-120 kg/ha active agent, but the N 80, P2O5 50, K2O 60 kg/ha fertilizer doses was the most effective. -
Optimization of inductively coupled plasma mass spectrometer parameter’s to measuring arsenic and selenium
59-64Views:629In the last decades an increased interest has been evolved about arsenic and selenium. The aim is to understand the environmental, agricultural and biological role of the these elements. In case of arsenic the mayor reasons are the relatively high concentration of arsenic in marine biota (mg kg-1) and the arsenic contaminated drinking waterbases of some Asian countries besides Hungary. The toxicity of higher level selenium content is also known, nevertheless selenium is essential for some biological functions. Considering its esssentiality, in our country the insufficient selenium intake rate couse lack of selenium. Measuring the concentrations of these elements are cruital but not satisfactory information, but the speciation, that is the form of an element presented in a sample is also required.
In both cases the most suitable method to determine concentration is the inductively coupled plasma mass spectrimetry. My objective was to optimase the changeable parameters of the ICP-MS for reaching the lowest (the best) detection limit. For this porpuse I have investigated the effect of parameter change on nett signal intensity and relative signal intensity. With the optimased parameter settings the limit of detection for arsenic and selenium were determined, which are 0,032 ng cm-3 for arsenic, and 0,097 ng cm-3 for
selenium. -
The effect of short term storage on different winter wheat varieties rheological properties
83-86Views:513The aim of storage after harvest is to protect the quality of wheat, because after-ripening occurs in the first 5–6 weeks. During this time it very important to make the optimal storage conditions.
We have carried out storage experiment with wheat samples from Látókép Research Farm of the University of Debrecen. We analyzed the rheological parameters of Lupus and GK Csillag varieties from the crop year 2011/2012. The experiment period was between July and August 2012 (24. 07. 2012., 31. 07. 2012., 21. 08. 2012.).We determined the rheological parameters (water absorption, dough stability time and valorigraph quality number) of Lupus and GK Csillag during short term storage. Our results showed that after-ripening increased the baking quality of Lupus and GK Csillag during storage.
-
Effect of anthocyanin-rich Hungarian tart cherry extract on blood antioxidant status in C57BL/6J mice
335-341Views:374In this study male C57BL/6J (B6) mice were used to determine the possible effects of our Hungarian tart cherry extract in a chronic obesity mouse model on antioxidant capacity.
The control group received standard mouse chow, the high fat control group was switched to high fat diet and tap water supplemented with 5% sucrose. The high fat+anthocyanin group received the high fat and sucrose diet, but dissolved in the drinking water they received anthocyanin-rich tart cherry extract. After six weeks, the antioxidant capacity and SOD activity were measured. Antioxidant capacity was decreased with a significant elevation of SOD activity. The tart cherry extract made a significant enhancement in antioxidant capacity and SOD activity. Our results show that chronic anthocyanin intake has a potential to enhance redox status associated with obesity.
-
Preparatory study for carbon sequestration modelling of agroforestry systems in Hungary: The assessment of the yield class distribution of windbreaks
73-78Views:187The escalating carbon dioxide emissions leading to global climate change are acknowledged as a paramount environmental challenge in the twenty-first century. The significance of land use systems in stabilising carbon dioxide levels and enhancing carbon sink potential has gained noteworthy attention from both the scientific and political communities. The Intergovernmental Panel on Climate Change emphasises that agroforestry systems present vital prospects for synergising climate change adaptation and mitigation efforts, offering substantial technical mitigation potential. Windbreaks are well-known agroforestry systems in Hungary and form an important part of agricultural landscapes. The improved agroforestry subsidy system in our country makes it relevant to model the carbon sequestration potential of windbreaks. In the framework of the ForestLab project we plan to develop a carbon sequestration model specific for Hungarian agroforestry systems. In this study, as a preparatory step of the model development, we assessed the yield class distribution of Hungarian windbreaks by tree species group and identified variables that had significant effect on yield class based on the data of the National Forestry Database. Our results show that among the examined effects the most important predictor of the yield class of windbreaks was the tree species group, followed by the thickness of the productive soil layer and the hydrology of the site.
-
Effects of ingredients and processing conditions on the quality frozen dough bread made from diferent wheat flour
115-120Views:142A laboratory scale no-time frozen dough procedure that approximates Romanian commercial practice has been
developed and used to study the effects of ingredients and processing conditions on the bread quality of a straight
grade wheat flour during prolonged storage (2 days to 26 weeks). All treatments (baking absorption level, mixing
energy input, mixer type, fermentation and intermediate proof times, removal of oxidant and/or dough
strengthening conditioners and partial freeze-thaw cycles) had significant effects (P<0.05) upon bread quality (loaf
volume and/or bread score). In general, these effects were more pronounced with extended frozen storage time.
High baking absorption, undermixing, bulk fermentation (> 1 h) and removal of oxidant and/or surfactants had
the most dramatic effects. Addition of a very strong flour at 30% to strengthen the wheat flour had no significant
effect (P>0.05) upon bread quality under optimum conditions. -
Examination of Possibilities for Increasing Sugar Content
202-206Views:99The result of sugar beet production is highly effected by the quality and the yield. Those agricultural techniques are very important which can be applied at low cost to improve these parameters. Such an opportunity is to increase sugar yield by foliar fertilization with nutrients and by treatment with bioactive fungicides.
In my small block trial I examined the effect of the magnesium and strobilurin active ingredients in different combinations and at different application times on the quality and the yield of sugar beet.
I found that there was a signifficant increase in sugar content on that blocks which were treated with a bioactive ingredient combined with magnesium in the middle of July and on those which were sprayed with bioactive ingredient in August. -
Complex assessment of inland water fish stocks
74-80Views:241In the domestic fish production, natural waters have yielded for several years about 7-8 thousand tons. This, from the point of view of outputs, considering the almost 130 thousand hectares of natural water, is rather low, it means approximately 55-60 kg/ha mixed fish.Although the various natural waters can differ significantly on the basis of yields, yet on the majority of the territories, the results were low. In the case of our extensive still waters and rivers, the reason can undoubtedly be found in the combined effect of the lack of the possibility of reproduction of the fish stock and the over-fishing. Fishery built on planning supposes the best possible knowledge in the given circum stances of the parameters of the water area and its fishstock. Lacking this knowledge, it is not possible to establish the optimal use fulness of the resources, what is more, the management can make faulty decisions – as a result of a lack of information -, which can risk the success of later activities.
It is known that many factors have an impact on the success of the fishery, as well as some information in connection with the water area and the fish stock are necessary, the knowledge of which make it possible to manage the fishery in a planned way. One part of the information is available, while the other part is incomplete or not deep enough. The necessary data are dissimilar depending on their nature, can be obtained from different places, by different methods.
As the first step for executing the field surveys and processing data, I developed a complex model, which contains in a unified system the steps of estimating the fishstock. I made the sampling on the basis of this. Part of the model is a fish faunistic survey, as well as a morphological survey of the water area. The information gained from these are important for making more accurate the system of devices of the samplings for stock estimation (duration, number of net-rows) and for assigning its place (places representing the best way the physical characteristics of the given water area). The major stages of stock-survey: A) faunistic survey, B) physical survey of the bed, and C) sampling with the help of gill-nets. This is followed by the evaluation by the computer module.
The results of the research create a methodological and technical background for the fish faunistic and population biologic surveys still performed in different ways in our country, and by applying these methods together, all basic information about natural waters which help decision-making concerning fisheries can be obtaine deffectively. -
The effect of different compost rates on the yield of ryegrass (Lolium perenne L.)
95-98Views:247Protection of natural resources and sustainable natural resources management are essential for the long-term survival of humanity. This makes necessary nowadays the development of environmentally conscious living and spread of that in the future. The amount of organic waste materials, produced during human activities, could be decreased by composting instead of dispose them in landfills. Applying appropriate treatment technology and additives, the compost could be used as fertilizer for horticultural crops and it could increase the easily available nutrient content of soils. Compost utilization prevents nutrient deficiencies and by using the optimal rate, we could reach significant yield increases.
-
Effects of a traditional agricultural sector’s decline in less favoured areas
109-114Views:195Due to the effects of economic and political transformations, privatization and accession to the EU, Hungarian agriculture has gone through significant changes in the last two decades. As a result of continuous changes in the economic and regulatory environment, producers have to plan and maintain cultivation and adapt to the changing market needs within continuously changing circumstances. These effects have resulted in a significant decline or in some cases, certain sectors have disappeared. These exercise a negative social and economic effect on all over the country, causing irreversible damages on those regions where agriculture is the only source of living. This paper discusses the effects of breakdown or disappearance of a traditional agricultural sector, namely the tobacco sector.
-
The effect of different fat content fish feed on the production parameters and meat quality of the hybrid striped bass
33-37Views:444The interspecific ’hybrid striped bass’ is the result of cross breeding. Their offspring have got good chances of growth and tolerate extreme water temperatures and the content of dissolute oxygen more than their parents. Furthermore, they are more resistant to diseases. Therefore, the hybrid is perfectly suitable for intensive fishery production.
Our experiment lasted for seven weeks. We analysed the indices of growth and production of the hybrid as the consequence of nurturing them with two feeds of high nutritive value during this period. We examined the content of fat and of fatty acids in the flesh of these fish. There were no considerable differences in terms of weight gain, feed conversion ratio and uneven growth between the two groups, while survival was less likely among the the fish which had consumed more fat. We demonstrated, examining the flesh of the individuals which had consumed feed containing lower fat content, that it was fattier and contained more dry matter than those that had been fed of higher fat content. Besides, the content of omega-3 and omega-6 fatty acids was higher in the fish that had consumed less lipids.
-
The examination of the marigold’s (Calendula officinalis L.) nutrient requirement in small-plot trial
61-66Views:269During our research we investigated the marigold's (Calendula officinalis L.) nutrient requirements with different fertilization treatments in small-plot trial. We measured the harvested marigold's drug's raw and dry weight on a weekly basis from July 6th until August 17th. We were using SPME (Solid phase microextraction) and GC-MS (gas chromatograph-mass spectrometer) to examined the effects of the different fertilization settings for the herb's main active ingredients of essential oil's percentage.
It was concluded, based on the results, the N30P40K60 fertilization setting is ideal in terms of the quantity of the marigold drug. Both the raw and the dry weights' measurements of the case, this fertilization setting have the most important effect on the herb's yield. The analysis of variance didn't show significant differences between the plots with different fertilization settings. We discovered relationship between the drying loss and the increasing quantities of nutrients. We think it may be possible the Alpha-thujon's and Alpha-cadinol's production and the drying loss's data are connected, which appear to confirm the N15P20K30 treatment's data.
-
Evaluation of decreasing moisture content of different maize genotypes
147-151Views:545An experiment was conducted to evaluate the decrease in grain moisture content in three maize hybrids in Debrecen in 2017. Armagnac, Sushi and Loupiac were the examined hybrids in this study. The culture medium and temperature conditions were applied uniformly for all three hybrids. According to the results obtained from the ratio of moisture content of seeds per day, the Armagnac variety in the intensive drying down phase loses more time and moisture content, so it can be concluded that the produced dry matter is more than in the case of other varieties. Armagnac requires more time to achieve yield, while the Sushi and Loupiac hybrids produce less harvest. Regarding the slope of the regression line, the rate of loss of moisture in the grain has been negatively correlated with the amount of “b” in the three examined hybrids. In regression analysis, the coefficient of explanation showed that the effect of day in the Armagnac was 97% in the Loupiac, 95% and in the Sushi 90% of the total dynamic value of moisture motion.
-
Measuring of nitrogen leaching using ceramic suction cups at different locations
10-17Views:173Ceramic suction cups were used for the measurement of N-concentration in soil solutions under different soil and climate conditions in both field experiments of Rostock University and Agricultural University of Debrecen (Hungary). Depending on the soil utilisation the change in the N concentration of the soil solution can be proved on both sites.
The experimental field of Rostock University can be characterised by its high groundwater table. The nitrogen concentration of soil solutions in the different soil layers were determined by the trend downward of water. In the dactylis (Dactilis glomerata) experiment, the quadruple treatments involved the following: with and without N-fertiliser, with and without harvesting, respectively. In the lower soil layers, the least rising N concentrations were established in case of the treatment without N-fertiliser combined with harvesting. The nitrogen leaching calculated from the infiltrated water quantity and the nitrate N concentration increased in the following order: without N-fertiliser, with harvesting < without N-fertiliser, without harvesting < with N-fertiliser, with harvesting << with N-fertiliser, without harvesting.
The field experiment site of Debrecen can be characterised by a low groundwater table. The effect of N-fertilisation on the nitrate-N concentration of soil solution in the soil layers can be stated unanimously. Permanent nitrate-N leaching cannot be established due to the water upward movement under semiarid climate conditions. Intermittently transfer of nitrate-N between the soil layers is probable in cases of remarkable precipitation. -
Examination of the Effect of Cropyear on the Yield Potential and Yield Stability of Winter Wheat Varieties
62-67Views:293Variety selection is one of the most important, determinative elements of sustainable winter wheat production. Yield potential, and yield stability are the most important elements in the variety selection of winter wheat, but baking quality parameters play an important role, too.
Several winter wheat varieties were tested for yield and yield stability on chernozem soil in the Hajdúság (in the eastern part of Hungary), in the 2001-2002-2003-2004 cropyears. The management factors were the same for all cropyears. 15 varieties in early the maturity group, 14 varieties in the middle maturity group and 4 varieties in the late maturity group were tested in the above mentioned cropyears. The climatic conditions were average in 2001, dry in 2002, extremely dry in 2003, and very favourable in 2004.
We obtained 5298-6183 kgha-1 yield from early maturity varieties, 5683-6495 kgha-1 from middle, 5694-6031 kgha-1 from late ones in the average of four years. The cropyears had strong influence on the yields, even on chernozem soil, and were characterized by excellent water – and nutrient – husbandry. Averaging of cropyears and genotypes, we obtained 6984 kgha-1 in 2001 (average cropyear), 5452 kgha-1 in 2002 (dry cropyear), 3120 kgha-1 in 2003 (extremely dry cropyear) and 8400 kgha-1 in 2004 (optimum cropyear), respectively. The yield differences between the minimum and maximum yields were 885 kgha-1 in early varieties, 812 kgha-1 in middle and 337 kgha-1 in late maturity varieties, respectively. The varieties characterized by high yield potential and the varieties characterized by good yield stability were different, so in variety selection we have to take both genetic traits into consideration. There were positive, significant correlations among the yields of winter wheat varieties (early, middle, late), the temperature of spring months. (March-April), and the rainfall of spring months (March-April) (R2=0,703**-0,768** and R2=0,681**-0,749**, respectively). We found a high negative correlation between the temperature of early summer months (May-June) and the yields of wheat varieties (R2= -0,856**- -0,918**).
According to the results of our experiment, it is very important to harmonize yield potential and yield stability in the variety selection of winter wheat.