...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">Plain and the influence of the hybrid, plant density, crop rotation, nutrient supply, weeds and irrigation on water use efficiency were studied.
The experiment was carried out in Debrecen, at the Experimental Station of the University of Debrecen Centre of Agricultural Sciences, Department of Crop Production and Applied Ecology. We tested 10 various hybrids with their own genetic characteristics for five different fertilizer doses, in addition to the parcels without fertilization. The t...hree factors of production technology jointly determine the successfully of maize production, but in different measure. The yield and the stability of yield of maize can be increased with hybrid-specific technologies.
In 2004-2005 experiment years the favorable results reached were due to the rainy season. There were significant difference between the productivity of maize hybrids. The N 40, P2O5 25, K2O 30 kg/ha treatment caused the highest increase of yield (3-5 t/ha) compared to the control (parcels without fertilization). The reaction of hybrids to the further fertilizer doses was different. The agro-ecological optimum of NPK fertilization was N 120, P 75, K 90 kg of the most hybrids.
During the experiment, we tested the moisture loss of the five hybrids. The seed moisture content at harvest was higher than in previous years due to the rainy seasons. The seed moisture content of harvest of FAO 200-300 hybrids were about 20%. It changed between 21-24% in the case of hybrids with longer vegetation period (FAO 400), the seed moisture content of Mv Vilma (FAO 510) was 24.21-25.04% in the average of fertilizer treatments. There is an important difference between the moisture loss ability of hybrids which changed 0.2-0.6%/day. The moisture loss of hybrids changed depending on the fertilizer treatment; usually, it was more favorable in the optimal fertilizer dose (N120+PK).
In the case of tested hybrids, we measured the highest LAI and photosynthetic activity at the optimal treatment, N 120, P2O5 75, K2O 90 kg/ha in the respect of efficiency and environmental protection, and the yield was high also for this treatment. There are significant difference between the LAI, the photosynthetic activity and the yield of hybrids, and these values could change depending on the treatment of fertilization.
Agricultural management practices – directly or indirectly – influence soil properties.
Fertilization rates and crop rotation can strongly affect soil pH, soil nutrient supply and soil organic matter content due to the changes of microbial processes. The objective of this study was to compare the effects of different fertilization d...oses in monoculture and tri-culture of maize (monoculture: only maize grown since 1983, tri-culture: it is a three-year crop rotation system: pea – winter wheat – maize) on selected soil characteristics. The long-term fertilization experiments were set up in 1983 in Eastern Hungary. These experiments are situated west of Debrecen in Hajdúság loess region, on calcareous chernozem (according to WRB: Chernozems).
The test plant was maize (Zea mays L.). One-one pilot blocks were selected from monoculture and tri-culture of the long-term experiments. The observed soil samples were taken in the 30th year of the experiment, in 2013. The doses of NPK fertilizers increased parallel together, so the effects of N-, P- and K-fertilizers cannot be separated.
With the increasing fertilizer doses, the soil pH has decreased in both crop production systems and, in parallel, the hydrolytic acidity has significantly increased. A close negative correlation was proved between the pHH2O, pHKCl and hydrolytic acidity. An increased nutrient content in soil was recorded in every NPK treatment and the available phosphorus and nitrate content increased in higher proportion than that of potassium. Of the measured parameters of C-and N-cycles, fertilization has mostly had a positive effect on the microbial activity of soils. Besides the effects of fertilizer doses, correlation were looked for between soil microbiological properties. Evaluating the ratios among the measured parameters (organic carbon and microbial biomass carbon, OC/MBC ratio; carbon-dioxide and microbial biomass carbon; CO2/MBC proportion), the fertilization rate seems to be favoured by the increase of amounts of organic compounds
Soil structure may be improved by adding readily decomposable organic matter. The extent of amelioration depends on the chemical build-up and decomposability of the crop residues. Three different kinds of organic matters were investigated: (1) maize stem, (2) wheat straw, and (3) maize stem
& wheat straw. Comparing the aggregate stabiliz
Knowledge of genetic diversity among available parental lines is fundamental for successful hybrid maize breeding. The aims of this study were to estimate (1) genetic similarity (GS) and genetic distance (GD) (based on Jaccard index) in four maize inbreed lines; (2) to classify the lines according to their GD and GS; (3) to determine hybrid per...formance based on GD and heterosis for yield ability in 4x4 full diallel system. We used morphological description and AFLP (amplified fragment length polymorphisms) for estimation genetic polymorphism in four maize inbred lines. We estimated the applicability of genetic similarity in SC and reciproc hybrids for prediction of their performance.
Three primer combinations were used to obtain AFLP markers, producing 207 bands, 70 of whit were polimorphic. The dendogram based on genetic similarities (GS) and genetic distance (GD) and morphological description separated four inbred lines into well-defined groups. Morphological description just with AFLP analysis showed reliable results. In view of genetic distance, the UDL 1 line and their linear and reciprocal crosses showed significant heterosis effect, which was confirmed by heterosis calculation based on grain yield.
Maize is a worldwide dominant plant. According to nowadays plant production principles it is important to investigate and optimize the site-specific nutrient-supply and other production factors, such as hybrid and irrigation, in the case of this plant as well.
At the Research Institute of the University of Debrecen, Center of Agricultural Sc
We have chosen three maize hybrids – that have been bread in Martonvásár – for our investigations. The effect of macronutrients is investigated in this experiment on five levels. The half of the experimental area can be irrigated during the vegetation period – whenever it is needed – by linear irrigation equipment, but on the other half only the water amount originating from the precipitation can be used by plants.
In the year 2008 the hybrid affected the grain moisture content at P=0.1% level, while nutrient-supply had an effect at P=10% significance level. We haven’t revealed either any effect of irrigation or of interrelationship between production factors. It can be stated that there are differences between the hybrids on each nutrient-supply and on both irrigation levels. The grain moisture content increased parallel to the longer vegetation
The starch content of maize is mostly affected by the hybrid,
so on P=0.1% significance level. Regarding our results, it can be
stated, that the starch content shows a decreasing tendency
parallel to the longer vegetation periods.
The paper is based on the researches carried out in the long term trial placed on the preluvosoil from Oradea in 1976, for establishing
the soil water balance. In the irrigated variant the soil moisture was determined 10 to 10 days for maintaining the soil water reserve on
irrigation depth (0 – 50 cm for wheat and bean, 0 – 75cm for m
cm for alfalfa 2nd year) between easily available water content and field capacity. Thus, an average irrigation rate of 2560 m³/ha was used
in the 9 experimental crops. The average of the annual rainfall for the 1976 – 2008 period was of 625.0 mm. The technologies used were
correlated with the needes of the crops, such as melioration crop rotation, chemical fertilizers in accordance with the chemical export on the
yield, manure (40 t/ha) was used in potato and sugarbeet. After 33 years of the irrigation use the soil structure degree (38.62%) did not
decrease when compared to the unirrigated maize – wheat crop rotation (37.01%). Bulk density, total porosity, penetration resistance and
hydraulic conductivity have worse values than the ones in the unirrigated variant. The humus content is very close to the humus content
determined in 1976, the phosphorus and the potassium content increased very much in comparison with the initial content (117 ppm vs 22.0
ppm); (180.0 ppm vs 102 ppm). The use of the adequate fertilization system and of the irrigation water with a good qaulity did not determine
a decrease of the pH value of the soil. The irrigation determined the improve of the microclimate conditions, the increase of the plant water
consumption, yield gains very significant statistically and higher protein content of the maize grains.
...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">We have conducted our research at the Látókép Research Farm of the University of Debrecen RISF Centre for Agricultural and Applied Economic Sciences during the cropyears of 2007, 2008 and 2009, on chernozem soil. In the case of crop rotation three models were set (mono-,bi- [wheat, maize] and triculture [pea, wheat, maize]). The five nutrient levels applied during the treatments were as follows: control [untreated], N60P45K45, N120P90K90, N180P135K135, N240P180K180. The conclusion of our results was the following: the crop rotation, the nutrient supply and the amount of precipitation all influenced the quantity of maize yield. As an effect of the increasing nutrient doses yield increase was experienced compared with the control treatments. In the average of the years the highest increase in yield excess/1 kg of NPK fertilizer was measured in the case of the monoculture (13 kg ha-1). As a consequence of is soil extorting effect the monoculture responded more intensively to the nutrient supplementation than the biculture or the triculture in the studied cropyears. In addition, we have observed that the three-year average yield amount per 1 mm precipitation was significantly influenced by the nutrient reserve of the soil. In the monoculture during the control treatment this value was 25 kg mm-1, the value measured in the case of the biculture turned out to be more favourable (42 kg mm-1).
Maize production plays a major role in the agriculture of Hungary. Maize yields were very variable in Hungary in the last few decades. Unpredictable purchase prices, periodical overproduction, the increasing occurrence of weather extremities, the uncertain profit producing ability, the soil degradation processes (physical, chemical and biologic...al degradation) and the high expenses are risk factors for producers. Due soil tillage, there is an opportunity to reduce these risks. Based on the experimental database of the Institute of Land Utilisation, Regional Development and Technology of the University of Debrecen, Centre for Agricultural and the KITE Plc., various cultivation systems were examined with maize (Zea mays L.) as indicator plant in Jász-Nagykun-Szolnok country in 2012 and 2013. The sample area can be found in the outskirts of Kenderes on a meadow chernozem soil. On the examined plot, strip-tillage, subsoiling and moldboard ploughing were performed, each on 4.5 ha, respectively.
In general, our findings show, that strip-tillage and subsoiling can be alternative tillage systems beside moldboard ploughing on meadow chernozem soils in Hungary.
Common smut disease of maize is one of the most frequent diseases of crop. In the last decades the importance of disease has decreased in feeding maize production, however its importance increasing again nowadays, especially at sweet maize hybrids. The aims of this work was to find hybrids possess of resistance, and to evaluate which ones are m...ore or less susceptible under field artificial inoculation circumstances. Among feeding maizes the less susceptible hybrid was ‘P9578’, and the most susceptible ’NK Columbia’ hybrid, and differences in cob infection between them was significant (8.8%). At sweet corn hybrids the less susceptible was ’Prelude’, while the most susceptible was ’Jumbo’ with very high significant 74.6% differences.
...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">As in other parts of the world, the frequency of weather extremes has increased greatly in Hungary in recent years. This means that maize production is faced with greater risks from all aspects: nutrient replacement, irrigation, plant protection. This is especially true of fusarium diseases. In a continental climate, the pathogens causing the most serious problems are species belonging to the Fusarium genus. They infect the ears, which – besides reducing the yield – poses considerable risk to both human and animal health due to the mycotoxins produced by them. Depending on which Fusarium species are dominant at a given location, changes can be expected in the level of infection and in the quality deterioration caused by the mycotoxins they produce. Fusarium spp. not only damages the maize ears but when pathogen attacks the stalk, the plant dies earlier, reducing grain filling and resulting in small, light ears. In addition, the stalks break or lodge, resulting in further yield losses from ears that cannot be harvested. The degree of infection is fundamentally determined by the resistance traits of the maize hybrids, but also a great role in that region Fusarium species composition as well.
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 yield and crop safety of maize are influenced by numerous ecological, biological and agrotechnical factors. It is of special importance to study one of the agrotechnical elements, the plant density of maize hybrids, which is influenced by the growing area conditions and the selected hybrid.
We have investigated the effects of three...different plant numbers (50 thousand plants ha-1, 70 thousand plants ha-1 and 90 thousand plants ha-1) on the yield of 12 maize hybrids of different genotypes in Hajdúság, on calcareous chernozem soil, in the Látókép Research Farm of the University of Debrecen, Centre for Agricultural Sciences, in 2013. The experiment was set in four replications, besides commonly applied agrotechnical actions. In the experiment, 1 hybrid of very early (Sarolta), 9 of early (P 9578, DKC 4014, DKC 4025, P 9175, NK Lucius, Reseda, P 37N01, DKC 4490, P 9494) and 2 of medium (Kenéz, SY Afinity) maturation were used.
With the increase of the plant number, the number of individuals per unit area increases. According to our experimental results, we have concluded that with the increase of the plant number, the yield increased in the average of the hybrids. In the average of the hybrids, in the case of 50 thousand plants ha-1, the yield was 13 130 kg ha-1, in the case of 70 thousand plants ha-1, it was 13 824 kg ha-1, while in the case of 90 thousand plants ha-1, the yield became 13 877 kg ha-1.
In addition to plant density increase, it is necessary to determine the optimal plant number that is the most favourable for the certain hybrid under the given conditions. To fulfil this aim, we have determined the optimal plant number corresponding to the maximum yield of the given hybrid, within the given plant number range. The optimal and applied plant numbers differ, since the optimal one could only be applied under ideal conditions. Since the agrotechnical actions cannot always be carried out in appropriate quality and one has to adapt to the weather conditions, thus we have determined a plant number range in the case of each hybrid. The hybrids were classified into categories of producible in narrow and broad plant number range.
...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">The comparative trial has been set up in the Demonstration Garden of the Institute of Crop Sciences of the University of Debrecen, Centre for Agricultural and Applied Economic Studies, Faculty of Agricultural and Food Sciences and Environmental Management in 2012, with 24 hybrids with different genetic characteristics and growing periods. The soil of the trial is lime-coated chernozem, with a humus layer of 50–70 cm.
The nutrient supply of plants is becoming more important in plant protection since the appropriate condition of plants can be ensured by optimal and satisfactory nutrient supply to avoid nutritional deficiency diseases. Due to the extreme weather conditions, plants are forced to face several stress factors, which lea...ds to deterioration of the plant health. The increasing occurrence of droughts poses threat to nutrient uptake through the roots since all the nutrients can be accessible to the plants only if they are in dissolved form in the soil – which is not possible in the absence of water. Therefore, the importance of foliar fertilizer is becoming a more and more significant part of the nutrient supply, because with the help of this technology the development of any nutrient deficiency can be prevented.
In this experiment, we focused on the efficiency of two different foliar fertilizers on maize. Foliar fertilizers were applied two times, once in the stage with 8 leaves and tasseling phenophase of the maize. To verify the efficiency of the foliar fertilizers, the chlorophyll content of untreated and treated plant’s leaves was measured after each application. Moreover, the length and diameter of maize cobs, thousand kernel weight, protein, oil and starch content were also measured, and the results were compared to the untreated (control) ones. According to the results, in all aspects significant differences were observed and due to the laboratory analysis of leaves, in the case of magnesium and zinc supply the foliar fertilizers were able to prevent the development of nutrient deficiency.
The maize research was set up on chernozem soil at Látókép research area of the Centre for Agricultural Sciences University of Debrecen. We examined the following hybrids SY ARIOSO (FAO 300), P9486 (FAO360), DKC 4943 (FAO 410). The experience was set u pin three different plant density. These were 60, 76 and 90 thousand plant ha-1.... The experience was set up in three different sawing date, early, average and late. The germination and growing dynamic measurements was measured in three hybrid, three sawing date, three plant density in four replication. well observed at the first sawing date (April 5) the soil was too cold therefore the germination was begins very slowly to be slowly increased. The second sowing time was the average (April 21) there the germination launch as soon as possible more rapid growth in the amount of heat. We experienced the most intense germination was in the case of the emergence late sowing date (May 5). Looking at the growth dynamics for the first two sawing date was side by side and almost equal to the maximum value. This is explained by the adaptive capacity of the maize to compensate for the sawing difference. For the third time, despite the delayed sawing the maize began to grow more dynamically than in previous sawing times due to the results of the initial good conditions it growth faster than halted in the second half of the season because of the high temperatures and lack of precipitation.
The herbicide tolerance levels of 49 Martonvásár inbred parents were examined in Martonvásár in a herbicide susceptibility trial in 2016. The normal dosage recommended in the permit documentations and double dosage were used for the 12 small-plot herbicide treatments performed in two repetitions. Spraying of early post-emergent herbicides w...as carried out in the 1–2-leaf stage, while post-emergent treatments were applied in the 7–8-leaf stage of maize. The extent of phytotoxicity was scored for the early post-emergent herbicides two and four weeks after treatments and for the post-emergent herbicides two weeks after treatments, respectively. Some of the herbicides examined are not approved in seed production; however it is important to know the reaction of maize parent genotypes for every type of herbicides. The active agent topramezone was withdrawn from the market in 2015, but it was included in the trials as its usage was allowed until stocks run out in 2016. The herbicide agents were examined as follows: mesotrione + S-metolachlor + terbutylazine; isoxaflutol + tiencarbazon methyl + cyprosulfamide; isoxaflutol + cyprosulfamide; mesotrione + terbuthylazine; tembotrione + isoxidifen-ethyl; mesotrione + nicosulfuron; prosulfu ron; nicosulfuron +prosulfuron + dicamba; bentazone + dicamba; nicosulfuron; topramezone; foramsulfuron + isoxadifen-ethyl.
Among early post-emergent herbicides, isoxaflutol + cyprosulfamide caused the less phytotoxic damage in the genotypes. The large amount of precipitation during the spring facilitated the infiltration of the active ingredient S-metolachlor, used regularly and successfully also in seed production, into the root zone, resulting in phytotoxic symptoms on susceptible inbred lines at the time of the first inspection. These genotypes recovered by the end of the vegetation period. The spring weather was cooler than usual, retarding the development of maize and thus led to the slower fermentation of herbicide active ingredients, accordingly, all of the post-emergent herbicides caused visible phytotoxic symptoms on some of genotypes. The most severe damages were generally caused by the double dosage of nicosulfuron + prosulfuron + dicamba, nicosulfuron, and foramsulfuron + isoxadifen-ethyl.
Investigations were made in Martonvásár on the herbicide tolerance of 22 inbred maize lines and 3 parental single crosses when treated with one herbicide applied after sowing, prior to emergence, and with seven applied post-emergence in the 6-8-leaf stage. Visible damage was scored 14 days after the treatment.
An analysis of the phytotoxic
The P uptakes of 11 different catch crops on four soils were estimated and compared with changes of double lactate soluble Phosphorus (P(DL)) in soil within a vessel trial. Additionally a model trial with quartz sand was carried out for investigations of the influence of P supply on root parameters. The differences of P uptake in dependence of...the proofed variants were significant. Under a sufficient P supply Buckwheat, Maize and Oil radish had the highest P uptake on sandy soils, on loamy soil also Buckwheat and Maize but Serradella too. Under P deficiency the withdrawals of Phosphorus for Buckwheat, Maize and Oil radish were found to be the highest. In contrast to the sandy soils for the loamy soils no significant relation between the P uptake by plants and changes in the P-DL amount in soil could be found. For all variants the P uptake by plants were higher than the reduction of the P-DL amount in soil. The rate of P-DL content on the total P content in soil reduced while the two trial years only in sandy but not in loamy soils. The P uptake, the root length and the root/shoot relationship depends significantly on the cultivated crop and the added P compound. The added water soluble KH2PO4 caused a higher P uptake but a lower root/shoot-relationship than the water insoluble P compounds.
The effect of production factors on maize yield was examined in the Látókép Experiment Site of the Centre of Agricultural and Applied Economic Sciences of the University of Debrecen on calcareous chernozem soil between 2001 and 2003. The impact of environmental factors (precipitation, temperature, number of sunny hours), cultivation methods...(autumn ploughing, spring shallow cultivation) and fertilisation (non-fertilised, 120 kg N + 90 kg P2O5 + 106 kg K2O, and 240 kg N + 180 kg P2O5 + 212 kg K2O) on maize yield was examined. During the three years, autumin ploughing significantly increased yield by 2.91 t ha-1 in comparison with spring shallow cultivation. The yield increasing effect of fertilisation was observed in each year, although its extent depended on the given crop year and the applied cultivation method. The higher fertiliser dose (240 kg N ha-1) did not cause significantly higher yield in either year. After the evaluation of the observed correlations, it can be established that the yield increasing
effect of fertilisation was higher in the case of autumn ploughing in comparison with spring shallow cultivation. The environmental factors (especially the extent of precipitation) significantly affected the maize yield.
Maize yield amount development is determined by the given crop year and the genotype of the applied hybrid, but beside these also by the applied agrotechnical factors, in particular by sowing technology. The development of yield amount and yield producing factors of five maize hybrids of different genotypes has been studied in a small-plot fiel...d experiment by the application of different row spacings and plant density variants. The production of the individual plants shows decreasing tendency parallel to the increasing plant density, however, this decrement is compensated by the higher number of plants per unit production area. Individual plant production is determined by the development of yield producing factors, such as the length and the diameter of cobs, just as by the thousand seed weight – that were studied in the present research work as well.
In the present research work the decreasing row spacing resulted in a yield increment of 0.67 t ha-1 (4.53%) in 2013, while in contrast in 2014 yield was decreased by 1.75 t ha-1 (14.87%). The high amount of precipitation in March was determinant in 2013: it filled up the soil water stock and balanced the negative effect of the inadequate amount and distribution of precipitation during the vegetation period for the yield. Lower extent of yield increment (0.6 t ha-1) was registered in 2014 in case of the row spacing of 76 cm than in the previous year. In case of a row spacing of 45 cm the difference between the two crop years was 3.1 t ha-1. The highest impact on the yield production factors was found in all treatment combinations in case of the applied hybrid among the three studied treatment factors. In the crop year of 2014 the effect of plant density on cob diameter and thousand seed weight could be revealed as well. In case of the cob diameter significant difference was found between the plant densities of 70 000 and 90 000 plants ha-1, just as between the populations with densities of 50 000 and 90 000 plants ha-1. In case of the thousand seed weight significant differences could be found by the application of plant densities of 70 000 and 90 000 plants ha-1. The highest values of the studied yield producing factors were measured in case of the plant densities of 50 000 and 70 000 plants ha-1; increasing the plant density to 90 000 plants ha-1 resulted in rather decreasing values.
The effect of NPK-fertilization on the dynamics of nutrient uptake of maize (Zea mays L., cv. Clarica) was examined on chernozem soil under irrigated and non-irrigated conditions in a field experiment.
The following results were made:
• the element concentrations in the plant decreased over time,
• there is no difference between th
• the N doses not only significantly increase the nitrogen content in maize, but also have a noticable effect on Ca and Mg concentrations,
• because of the acidifying effect of N-fertilizers, increasing the amount of N-fertilizer increased the Mn, Zn, Cu content of the plants,
• the P doses have a significant effect on the maize P and N content and the Zn concentration of the plant via P-Zn antagonism in the soil,
• as the high K doses treatments alter the ion ratios in the soil, the Ca, Mg content of the plant decreased.
The successfulness of crop production is significantly affected by not only the the average yields that provide cost effectiveness, but also the success of striving for yield safety, therefore, varieties and hybrids tolerant to environmental stress factors are worth being included into the sowing structure. Our aim was to further the decision m...aking of producers in prepaering the right sowing structure by the evaluation of sweet maize hybrids’ tolerance to excess rainfall.
We performed our examinations in an extremely wet year (2010) on chernozem soil on three sweet maize hybrids (GSS 8529, GSS 1477, Overland) in 12 replications. Comparing the yields of 2010 with those that can be expected under optimal rainfall conditions, we showed that the examined hybrids react to the amount of rainfall higher than their needs with yield depression. The excess rainfall tolerance of the examined hybrids is different in the case of each hybrid.
In this paper, we analysed the results of maize sowing time experiments conducted by the Department of Crop Sciences and Applied Ecology of the University of Debrecen Agricultural Sciences Centre, during the period from 1997-1999. We made the experiments at the experimental garden of DE ATC, on a chernozem soil with lime deposits.
In 1997, w
We examined the following standards: yield, seed moisture content at harvest, thousand kernel mass, duration of flowering, emergence time and profitability.
In 1977, the emergence times, in order of sowing, were: 24, 12 and 9 days. Yields of the sowing times were the following, in mean, for the five hybrids: in the early sowing time (10. Apr.) 11,81 t/ha, in the optimal sowing time (25. Apr.) 11,67 t/ha, and in the late sowing time (15. May) 12,9 t/ha. The seed moisture content of the five hybrids at harvest was 8% less in early sowing time, than in the late sowing time. The thousand kernel mass was the biggest in late sowing time, but we could not prove any significant connection attributable to the effect of sowing time. We examined
profitability, too. Of the five hybrids, four attained the greatest profit with the early sowing time in 1997.
In 1998, the emergence times, in the order of sowing, were: 21, 10 and 11 days. Yields of the sowing times were the following, in mean, for the six hybrids: 08. Apr. 10,34 t/ha, 25. Apr. 11,02 t/ha, 15. May 11,52 t/ha. There were no significant differences between yields in 1998. The seed moisture content of the six hybrids at harvest was 7% less for the early sowing time, than for the late sowing time. In 1998, the profits were greatest for the
early and traditional sowing times.
In 1999, the numbers of days from sowing to emergence were 18, 9 and 9 days, in the order of sowing times. Yields of the sowing times were the following, in mean, for the three hybrids: 13,25 t/ha, 12,51 t/ha and 12,34 t/ha, in the order of sowing times. The seed moisture content of maizes at harvest was 6% less with an early sowing time in the mean of all hybrids. In 1999, hybrid maizes gave big profits with early sowing times.
Summing up the results of the three years, we can conclude that we get a significant yield increase and reduced seed moisture content at harvest if we apply the early sowing time, which can considerably increase the efficiency of maize cultivation.
In order to enchance the yield stability of maize, the effect of plant density on yields was studied on a typical meadow soil in Hajdúböszörmény between 2002-2004. In the plant density experiment, we used the method of Béla Győrffy. The plant densities applied therefore 20 to 100 thousand plants/ha by ten thousand scale. The application o...f fertilizer rates for the maize hibrids in every year were N: 110 P: 90 K: 120 kg/ha. We used a manual soiling-gun in the experiment. In every year we used plant protection techniques against monocotyledonous and dicotyledonous weeds. The harvest was done by hand. The facts were read by variancie analysis and linear regression analysis. The moisture and the temperatures were extreme in 2002, 2003, 2004. We have to mention defficiery of moisture in 2003 which is shown that the hot days number increased. After evaluating our findings we can conclude that most hybrids showed a significant correlation between increased plant density and the volume of yields. On the basis of the experiments we divided the hybrids into four groups: the first group included the hybrids suitable for increased plant density with a wide range of optimal density values; the second group included hybrids, which did not require high plant density, were capable of good individual performance and tended to grow several ears; the third group included flexible corn types, which grew longer ears in favourable years, thus yielded more; and the fourth group included the hybrids, which were sensitive to increased plant density and which showed a narrow range of optimal density values. Finally, plant density determines the yield; we have to consider optimal plant density intervals as well as optimal plant density, and we also have to place a high emphasis on the use of hybrid-specific technologies.