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.
In 2015 eight, in 2016 ten hybrids with different genetic characteristics and growing seasons, with control (without fertilization), N80+PK and N160+PKtreatments, five plant densities (50–90 thousand) with 10 thousand plants difference between the different densities.
The millet is a very special plant with good adaptation that gives the possibility for the late sowing and secondary production. However the effects of late sowing modifies the efficiency of the agrotechnological elements. The exainations – focused on this aspect – was conducted in the DU RINY and DU RIK in small plots in four replications ...in 2014. Among the examined factors (sowing time, nutrient supply, growing area) sowing time had the largest effect. The effectiveness of the agrotechnological elements decreases under unfavourable circumstances caused by the late sowing.
The agrotechnical elements modifies the yields in the examined genotype. Sowing time had the biggest effect on the yields of millet. The genotype „Maxi” had the highest yield in the different treatment variations.
The yield differences were significant between the sowing time and plant density variations, but the nutrient supply had not significant effect (the rate of precipitation was unfavourable in 2014 season).
The experiments were set on lime-coated chernozem soil in 2013 and in 2014, in our study four hybrids were included with different FAO number. We studied the effect of NPK fertilization and row spacing on the yield. The fertilizer doses were based on a 25-year longterm experiment. Compared to control, the N40 +PK treatment has also achieved a s...ignificant yield increase, although some hybrids responsed with yield loss to the increasing fertilizer doses; this effect was observed especially in 2014. The majority of hybrids reached higher yields in both years using the 50 cm row spacing. The water release of hybrids was measured weekly during the maturation, at the same time points. The rainy September slowed ripening and the water release of the hybrids in 2013, so the grain wet content at harvest showed higher values. The moisture contents were increased for some hybrids, in spite of the positive and favorable dynamic of water loss.
Our sowing date experiment took place in the Demonstration Garden of Institution of Plant Sciences, Agricultural Center of University of Debrecen, in 2012–2014. The thesis contains data of test year 2014. Our purpose, besides several other examinations, was to observe how sowing date influences leaf area index and activity of p...hotosynthesis of maize hybrids, and how those factors affect fruiting. In the experiment we monitored the change of the leaf area index and the photosynthesis of hybrids with four different growing seasons.
Based on the results, it can be concluded that most of the examined hybrids reached their smallest leaf area with the third sowing date and with the highest yield results. Hybrid Da Sonka had the largest leaf area (4.10 m2 m-2), and hybrid DKC 4590 produced the highest yield (13.16 t ha-1)
with the third sowing date.
During testing the photosynthetic capacity, the extremely high performance of the youngest plants with the third sowing date is outstanding, which can be explained by the different ripening periods. Examination of the correlation between the photosynthetic capacity and the yield, by linear regression analysis, also proves that photosynthesis has a determinative role in fruiting.
The results obtained confirm that not only the environmental and agricultural factors in the growing season have effect on the yield, but also other factors like the leaf area index and the photosynthesis are determinative parameters, and all those factors together, modifying effects of each other, develop average yields.
dramatically in the last few decades. We are lagging behind Western European countries as regards yields. The ecological conditions are not favourable for potato, but the low yields other causes: the use of non-suitable seed, the low level of irrigation and nutrient supply and out of date machinery. The competitiveness of production is further ...decreased by the great alternation in yields from year to year, unpredictable market conditions, poor consumption habit, and often the lack of quality products.
The experiment was carried out at the experimental site of the University of Debrecen, Farm and Regional Research Institute, at Látókép. In our experiment, we examined the yield and selected quality parameters of 9 medium-early varieties in large parcels. Of the examined varieties, 3 are of Dutch, and 6 are of Hungarian breeding.
The experiment was set up in 2004 and 2005, on 50 m2 parcels on calcareous chernozem soil after winter wheat (2004) and two rowed barley (2005) as a forecrop. The varieties were examined in 4 repetitions in randomized blocks, of which two repetitions were irrigated, and two were non-irrigated. We examined the yields of the varieties, the distribution of tubers according to size and their percentages and changes, and selected parameters of quality and chemical composition due to irrigation. We studied the dry matter content, the starch content, the underwater mass, the amount of reducing sugars, and the colour index of frying of the tubers.
Summary, it can be stated that among the agrotechniques, year effect, variety and irrigation factors have considerable impact on potato yield quality and quantity. However, the impact of irrigation depends on the year effect.
The yielding capacity and quality parameters of 11 maize hybrids were studied in 2011 on calcareous chernozem soil in a 25-year long-term fertilization experiment in the control (without fertilization), in the base treatment of N 40 kg ha-1, P2O5 25 kg ha-1, K2O 30 kg ha-1 and in... five treatments which were the multiplied doses of the base treatment. The N fertilizer was applied in the autumn and in the spring, while P and K fertilizers were applied in the autumn.The sowing time was 17–18 April, the time of harvest was 8 October. The 30-year average of precipitation (April–Sept) was 345.1 mm, the amount of precipitation did not differ greatly from that, however, its distribution was very unfavourable.
It was found that the largest yield increment (as compared to the control) was in the treatment N 40 kg ha-1, P2O5 25 kg ha-1, K2O 30 kg ha-1 in the long-term experiment. The largest yields were obtained for the hybrids P9494, PR37N01 and PR35F38 (13.64–13.71 t ha-1). Due to the dry period at the end of the summer – beginning of autumn, the grain moisture content at harvest was favourably low, 12–18% depending on the treatment and the growing season.
The N fertilization significantly increased the protein content of the kernel, but the starch content of the kernel decreased (significantly in several cases) with increasing fertilizer doses and yields as compared with the control.
The highest protein content was measured in hybrids GK Boglár and Szegedi 386. The oil content was above 4% for GK Boglár, but the two hybrids were not among the best yielding hybrids in spite of their good inner content. The starch content was around 75 % without fertilization, it decreased with fertilization.
For the tested hybrids, the fertilizer dose N 120 kg ha-1, P2O5 75 kg ha-1, K2O 90 kg ha-1 can be recommended with respect to efficacy and environmental considerations.
Several factors influence the quantity and stability of maize yield, the most important being the nutrient supply, the hybrid and precipitation. In 2004, during the maize growing season the precipitation was more than the 30 year’s average, with 68.3 mm, but the distribution was unfavorable. The experiment was carried out in Debrecen at the E...xperimental 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 favorable results reached were due to the rainy season. The average yield varied between 7.78-9.67 tha-1. The DK 440, PR37M34, PR38A24, PR39D81 and PR36R10 of the hybrids reacted to higher fertilizer doses with significant growth yields, the yield (more than 11 tha-1) was the highest for N200, P125, K150 fertilizing. The other hybrids, DKC 5211, Mv Vilma and MV Maraton, gave similar results at the N120+PK fertilizer dose and the ensuing doses depressed the yield. Fertilization was more effective thanks to the precipitation. The fourth and fifth dose increased or decreased maize yield depending on the nutrient reaction of the hybrid. The agro-ecological optimum of NPK fertilization was N120, P75, K90 kgha-1.
During the experiment we tested the moisture loss of five hybrids. The rainy crop year’s effect on the seed moisture content at harvest was higher than in previous years. The seed moisture content hybrids at harvest which have shorter crop years (FAO 300) was 18-19%, and hybrids with longer vegetation periods had more than 20% seed moisture content. DK 440 hybrid had the intensive moisture loss of the five hybrids, at the start of the measurement, the seed moisture content was higher than 40%, and it decreased to 18.6% by harvesting.
In Hungary, the growing area of potato area dropped dramatically in the last few decades. Additionally not only are we lagging behind Western European countries as regards yields, but the competitiveness of production is further decreased by the great alternation in yields from year to year, unpredictable market conditions, poor consumption hab...its and, often the lack of quality products.
The experiment was carried out at the experimental site of the University of Debrecen, Farm and Regional Research Institute, at Látókép. In our experiment, we examined the yield and some quality parameters of 9 medium-early varieties in large parcels. Of the examined varieties, 3 are of Dutch, and 6 are of Hungarian breeding.
The experiment was set up in 2003 and 2004, in two years of significantly different precipitation, on 50 m2 parcels on calcareous chernozem soil after winter wheat as a forecrop in both years. The 9 varieties were examined in 4 repetitions in randomized blocks, from which two repetitions were irrigated, and two were non-irrigated.
We examined the yields of the varieties, the distribution of tubers according to size and their percentages, and the changes in specific parameters of quality and inner content due to irrigation. We studied the dry matter content, the starch content, the underwater mass, the amount of reducing sugars, and the colour index of frying of the tubers.
In Summary, it can be stated that among the agrotechniques, year effect, variety and irrigation factors have considerable impact on potato yield quality and quantity. However the effect of irrigation depends on the crop year. In a draughty year, like in 2003, irrigation could increase the yield by 10%, while in a more favourable wet year, the improving effect of irrigation was low.
Maize is one of the most important crops worldwide and also in Hungary, it can be utilized for multiple purposes: as a feedingstuff, for human nutrition and for industrial processing. In the last decades, the per ha yield of maize varied greatly in Hungary, between 2004 and 2006, it was 6.82-7.56 t/ha, while in 2007, it was only 3.6 t/ha. Resul...ting from this, the price of maize became 2-2.5 times higher. The high price hinders bioethanol production. The largest per ton amount of bioethanol, 387 l, can be produced from maize.
In addition to its classical utilization as feed and food, the industrial use (especially for bioethanol production) of maize is increasin.
For industrial production, a new production technology is needed. I tested and selected hybrids appropriate for this purpose and set up fertilization and plant density experiments. The experiment were set up on chernozem soil in 2007.
The applied fertilization treatment was N 120, P2O5 80 uniformly, and five different dosages of potassium: K2O 0, K2O 100 (KCl), K2O 100 (Kornkáli), K2O 200 (KCl), K2O 200 (Kornkáli) kg/ha active ingredient. The applied plant densities were 40, 50, 60, 70, 80, 90 thousand plants/ha.
The yield of maize hybrids in the fertilization experiment ranged between 10.53 – 14.62 t/ha. Both regarding the form and dosage, 100 kg/ha Kornkáli proved to be the best potassium treatment. Regarding the inner content parameters, the highest starch content in the average of treatments was obtained for the hybrid PR36K67: 73.57%, and its yield was also the highest, so this hybrid proved to be the most suitable for bioethanol production. The highest protein content was observed for the hybrids KWS 353 (12.13%), which can be favourable for feeding purposes.
Most of the hybrids gave the highest yield at 80 thousand plants/ha plant density, however, hybrids PR36K67 and Mv Tarján achieved the highest yield at 90 thousand plants/ha.
In bioethanol production, the selection of a high-yielding hybrid with high starch content, a slight reduction of N, increase of potassium, the application of the highest plant densities of the optimum interval, harvest at full maturity (when starch content is the highest compared to protein content) are of great importance.
The effect of sowing date on maize development and yield was studied in field experiments. The experiment was set up at the experimental garden of the University of Debrecen Centre of Agricultural Sciences Faculty of Agriculture, Department of Plant Sciences in 2005 and 2006 on calcareous chernozem soil. Six hybrids with different genetic chara...cteristics and vegetation period were tested (Sze 269, DK 440, PR37D25, NK Cisko, Mv Maraton, PR34B97) at three different sowing dates.
2005 was a very wet year. The amount of precipitation in the vegetation period was about 150 mm higher than the average of 30 years. No significant differences were observed in temperature. However, the number of sunny hours was much lower during the summer than as usual. This had an influence on yields.
In 2006, there was no risk of inland water in spite of the large amount of precipitation at the beginning of the year. The amount of water available for plants was satisfactory during the season due to the favorable amount of precipitation. Therefore, plants suffered less from the heat in July. However, hail on 22 July caused significant damage. The number of sunny hours in the summer was high enough. The warm, dry autumn helped the water release of plants.
In 2005, the results of the third sowing date could not be evaluated due to the large number of missing plants. The yield of hybrids ranged between 12-14 t/ha for the first sowing date. For the second sowing date, yields ranged between wider boundaries. The hybrid PR37D25 has a very high yield in the case of the second sowing date, and its seed moisture content was favorably low. The yield of hybrid PR34B97 was the lowest at the later sowing date, the prime reason of this was damage caused by Diabrotica virgifera. The seed moisture content at harvest varied between 16-24% for the first sowing date. In the case of the second sowing date, higher values were measured. Hybrids Sze 269 and NK Cisko had favorable water release characteristics. The maximum value of leaf area index was the best in the case of the first sowing date (5-5.5 m2/m2).
In 2006, yields for the first sowing date ranged between 8-10 t/ha. At the second sowing date, more favorable results were obtained. The reason for this is probably that hail caused a higher damage in hybrids with the early sowing date. Plant stock with later sowing date could recover more successfully. Hybrid PR37D25 had very high yields for the second and third sowing dates. The high-yielding hybrid PR34B97 also had high yield, but this was accompanied by higher seed moisture content. Due to the warm, sunny autumn weather, the hybrids had good water-release dynamics and were harvested with a lower seed moisture content than in the previous year. For the first sowing date, the seed moisture content was around 13-14% except for hybrid PR34B97. For the second and third sowing dates, higher values were observed. Leaf area index was significantly reduced in August for all three hybrids due to the hail in July. For the first two sowing dates, the leaves of hybrid Sze 269 were the first to dry similarly to the previous year.
Year had a strong effect on the results in both years.
In Hungary, the growing area of potato area reduced dramatically in the last few decades, additionally we are lagging behind the Western European countries as regards yields and the competitiveness of production is further decreased by the great alternation in yields from year to year, the unpredictable market conditions, bad consumption habits... and many times unfortunately the lack of quality products.
The ecological and climatic conditions of Hungary are not everywhere suitable for potato, in the area of Debrecen the amount of rainfall was lower, and the monthly average temperature was higher than the requirement of potato in its growing season in 2002 and 2003.
The experiment was carried out at the experimental site of the University of Debrecen, Farm and Regional Research Institute, at Látókép. In our experiment we examined the yield and some quality parameters of 8 and 9 medium-early varieties in large parcels in 2002 and 2003 respectively. Out of the examined varieties 3 are of Dutch, and 6 are of Hungarian breeding.
The experiment was set up on 49.5 m2 parcels on calcareous chernozem soil after winter wheat as a forecrop in both years. The 9 varieties were examined in 4 repetitions in randomized blocks, out of which two repetitions were irrigated, and two were non-irrigated.
We examined the yields of the varieties, the distribution of tubers according to size and their percentages, and the changes in specific parameters of quality and inner content due to irrigation. We studied the dry matter content, the starch content, the under-water mass, the amount of reducing sugars, the colour index of frying and the element contents of tubers.
Summing up, it can be stated that among the agrotechnical year effect, variety and irrigation factors have considerable impact on potato yield quality and quantity. On the basis of our results, it can be stated that in potato production variety should be chosen in accordance with the aim of production and technology should be adapted to that specific variety.
Maize is one of Hungary’s major cereals. In the 1970s and 1980s, we were in the frontline regarding yields and genetic advancement. However, yield fluctuation in maize has increased to 50-60% from 10-20% since the 1980s, which was partly caused by the increase in weather extremes due to climate change and by agrotechnical shortcomings.
The... experiments were carried out on typical meadow soil in four repetitions in the period of 2007-2008. In the sowing time experiment, sowing was performed on 10 April, 25 April, 15 May under a uniform fertilization of N120, P2O580 K2O 110 kg/ha. In the fertilization experiment, the yielding capacity of 10 hybrids with different genetic characteristics was studied in a control (non-fertilized) treatment and basic treatment of N40 P2O5 25, K2O 30 kg ha-1 active ingredient and a treatment with fivefold dosages of the basic treatment. In the plant density experiment, the relationship between plant density and yield was analysed at plant densities of 45, 60 and 75 thousand plants per ha. We found a tight correlation between sowing time and yield and grain moisture content at harvest. We found that grain moisture can be reduced by 5-10% by applying an earlier sowing time.
The agroecological optimum fertilizer dosage was N 40-120, P2O5 25-75, K2O 30-90 kg ha-1 active ingredient at a plant density of 60-90 thousand plants ha-1 depending on the hybrid and the year.
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...e examined five hybrids, in 1998 six hybrids, and in 1999 three hybrids, with three sowing times. Sowing times were early (10. Apr. and 08. Apr.), optimal (25. Apr. and 28. Apr.) and late (15. May and 17. May).
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.
For industrial (bioethanol) production of maize, a new production technology is needed. I tested and selected hybrids appropriate for this purpose and set up fertilization and plant density experiments. The experiment were set up on chernozem soil in 2008.
In bioethanol production, the selection of a high-yielding hybrid with high starch con...tent, a slight reduction of N, increase of potassium, the application of the highest plant densities of the optimum interval, harvest at full maturity (when starch content is the highest compared to protein content) are of great importance.
Besides its effect on potato yield, water also has a significant impact on yield quality. Excess water (too much precipitation, over-irrigation) and the lack of water (lack of precipitation or irrigation) both trigger stress in the plant and can significantly worsen the quality of the yield (seed potato) and deteriorate the health of the plant ...and the seed potato. Excess precipitaton or irrigation water leaches nitrate-nitrogen under the rhizosphere, consequently, the amount of available nitrogen decreases leading to the deficiency of N in potato. If water cover (the maximally saturated state of soil) exceeds 8-12 hours, it can cause root destruction (because of the lack of oxygen), which leads to the wilting and later to the death of the plant. Abundance of water caused by excess precipitation or irrigation is a major problem primarily on sandy loam, loam and clay loam soils with bad structure and water management qualities, but also on any soils, which are over-irrigated or irrigated at an improper time. Symptoms of the lack of water are detectable mostly when the available water content of the soil (disponible water) decreases under 60-65%.
In the present year, there was a lack of precipitation on the Great Plain, which can be compensated by proper irrigation. Unfortunately, this problem is further intensified by the high temperature, which results in faster ripening and accompanied with fluctuating soil moisture content, in the formation of secondary tubers.
The yield safety of maize has not been satisfactory in Hungary for decades. Yield is influenced by the combination of several factors.
In recent years, the frequency of dry years increased and fertilization decreased. These factors call for a rational determination of the plant density.
I studied the relationship between plant density and... yield in 2003-2004 and 2007 on meadow soil.
In 2003, the weather was dry. In the vegetation period, the amount of precipitation was 78.5 mm lower and the temperature was 0.97 °C higher than the average of 30 years, the number of hot days was 47-60 (days with a temperature higher than 30 °C). However, we obtained favourable results under experimental conditions in 2003 after wheat as a forecrop using the fertilizer Kemira Power.
The weather in 2004 was favourable. In the vegetation period, the amount of precipitation was 93.2 mm higher than the average of 30 years. Although, the distribution of the precipitation could have been more favourable. The yield of the hybrids ranged between 8.87-10.42 t/ha. Among the studied seven hybrids, the early hybrids gave the highest yield at the highest plant density of 90 thousand plants/ha (PR38Y09, PR38A67, PR37D25, PR37M34). However, FAO 400-500 hybrids gave favourable results also at the low plant density of 45 thousand plants/ha (8-9 t/ha). At this plant density, the aeration of the plant stock was better and the hybrids were prone to bringing several cobs. Yield stagnated with increasing plant density (60 thousand plants/ha), then at 75-90 thousand plants per ha, the yield started to increase again.
In 2004 the yield of hybrids was considerably higher than in the previous year. In contrast to yields of 8.87-10.42 t/ha in 2003, yields in 2004 were around 9-12 t/ha.
The yield of the hybrid XO 902 P is above 12 t/ha already at a plant density of 45 thousand plants/ha. It gives maximum yield at the plant density of 90 thousand plants/ha.
The hybrid PR38P92 showed a good response to changing plant density, but its yield was only 9 t/ha at the low plant density value.
In a favourable year, the yield of the hybrids PR38B85, PR37W05, PR37D25, PR37K85 at a plant density of 45 thousand plants/ha 11 t/ha, while at the higher plant density of 90 thousand plants/ha, it ranges around 13-15 t/ha.
Hybrids PR36K20, PR35Y54, PR34H31 have a good individual yield and they are prone to bringing several cobs in favourable years at a low plant density. Their maximum yield at the plant density of 90 thousand plants/ha is almost 16 t/ha.
In 2007, the weather was similar to that of the extremely dry year of 2003. The amount of precipitation in the vegetation period was 41.9 mm lower than the average of 30 years and its distribution was not favourable either.
In the optimum NPK fertilizer treatment at an optimum plant density, the yield of hybrids ranged between 9.32-10.73 t/ha. The highest yields of 10.22-10.73 t/ha were measured for hybrids PR38A79 (FAO 300) and PR35F73 at a relatively low plant density of 60 thousand plants/ha.
In the average of the hybrids, the optimum NPK dosage was N 131, P2O5 82, K2O 93 kg/ha active ingredient.
Sowing time is an important crop technology element of maize. We studied the effect of this factor on the growth and production of maize in an experiment carried out near Hajdúböszörmény, in 2003 and 2004, and near Debrecen, in 2005.
The soils of the experiments were humic gley soil and chernozem. Weather in both years differed greatly. ...2003 was drought. Neither the distribution, nor the quantity of the precipitation were suitable in the growing season for maize. This fact basically determined the results.
In 2004 and in 2005, there were favorable and rainy seasons. The distribution and quantity of precipitation were suitable between April and September. The average temperature was also suitable for maize.
In 2003, we tested seven hybrids at four sowing times. Hybrids with a shorter vegetation period gave the highest yield at the later sowing time, while the hybrids with a longer vegetation period gave them at the earlier sowing time. The yield of PR34B97, PR36N70, PR36M53 hybrids were the best at every sowing times. The moisture loss of hybrids in the late maturity group was faster in the maturity season, but the seed moisture content was higher than the hybrids with early sowing time. The seed moisture content was very low due to the droughty year. In two hybrid cases, this value was higher than 20% only at the fourth sowing time.
In 2004, we examined the yield and seed moisture contents of nine hybrids. In the favorable crop year, the yield of every hybrid was the highest at the second and third sowing times. Yields of PR34H31 and PR38B85 hybrids were significant. The seed moisture content at harvest was higher than the previous year, due to the rainy season. In the case of hybrids sown later, this value was higher by 30%. However, we noticed that this value was lower at the earlier sowing time, than at the later.
In 2005, we applied three sowing times. Unfortunately, the results of the third sowing time could not be analyzed, due to the low plant density. The yield of the six hybrids varied from 12 to 14 t/ha at the first sowing time. At the second sowing time, the yields fluctuated and each hybrid had the lowest yield, except the PR37D25 hybrid. At the latest sowing time, the yield of the PR34B97 hybrid was the lowest. However, this low yield was due to damage from the Western corn rootworm (Diabrotica virgifera) imago. The moisture content at harvest of the hybrids varied from 16 to 24% at the first sowing time. Yields at the second sowing time were higher. The low yield of the PR34B97 hybrid coupled with a higher seed moisture content. In addition, the maximum value of the LAI was more favourable at the first sowing time, and ranged between 5-5.5 m2/m2.
The crop year had a more dynamic effect on maize than the sowing time. First of all, the quantity and distribution of precipitation played an important role in respect to yield safety.
Sowing 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, b...ecause 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.
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.
Cultivation factors have a significant effect on the yield and yield security of maize. Ensuring a suitable green crop is important. Tricultural crop rotation (pea–wheat–maize) in the average of 25 years provided a 2 t ha-1 higher yield compared to monocultural cultivation. A harmonious NPK nutriment supply determines yield and y...ield security, which can be especially realized by means of the application of precision cultivation technologies. Under average circumstances N 80 kg ha-1, P2O5 50 kg ha-1, K20 60 kg ha-1 active ingredient is the agro-ecological dosage of artificial fertilizer.
Plant density is a factor that determines yield. Optimal plant density – beside the genetic characteristics of the hybrid – is mostly influenced by the level of water and nutriment supply.
The crop technology of maize has two important elements, sowing time and plant density. In 2003 and 2004 we studied the effect of these two factors on the growth and production of maize in an experiment carried out near Hajdúböszörmény.
The soil of the experimental plots was meadow soil.
Weather in both years was differed greatly. 200...3 was drought. Neither the distribution nor the quantity of the precipitation were suitable in the growing season for maize. This fact basically determined the results.
In 2004, we could talk about a favorable and rainy season. The distribution and quantity of precipitation was suitable between April and September. The average temperature was also suitable for maize.
Results of the sowing time experiment:
In 2003, we tested seven hybrids at four sowing times. Hybrids in the early maturity group gave the highest yield at the later sowing time, while the hybrids of the long maturity group gave it at the earlier planting time. The yield of PR34B97, PR36N70, PR36M53 hybrids was the best at every planting time. The moisture loss of hybrids in the late maturity group was faster in the maturity season, but the seed moisture content was higher than the hybrids with early sowing time. The seed moisture content was very low due to the droughty year. In two hybrid cases, this value was higher than 20% only at the fourth sowing time.
In 2004, we examined the yield and seed moisture content of nine hybrids. In the favorable crop year, the yield of every hybrid was the highest at the second and third sowing time. Yields of PR34H31 and PR38B85 hybrids were significant. The seed moisture content at harvest was higher than the previous year due to the rainy season. In the case of hybrids sown later, this value was higher by 30%. However, we noticed that this value was lower at the earlier sowing time than at the later.
The crop year had a more dynamic effect on maize than the sowing time. First of all, the quantity and distribution of precipitation played an important role in respect to yield safety.
Results of the plant density experiment:
We tested the reaction of hybrids at four plant densities (45,000, 60,000, 75,000 and 90,000 stock/ha) every two years. In 2003, the tested seven hybrids reached the highest yield at the 90,000 stock/ha in the face of a droughty year. The effect of forecrop and favorable nutrients caused these results. In the rainy 2004 year, the yield grew linear with the growing plant density. The yield of the best hybrids were 14-15 t/ha at the 90,000 stock/ha.
Such a high plant density (90,000 stock/ha) couldn’t adaptable in farm conditions in rainy season. It is practical to determine the interval of plant density besides the optimum plant density of hybrids which gave correct yield. The farmers have to use the low value of this interval due to the frequent of the droughty years.