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Role of Sowing Time in Maize Production (Review)
36-39Views:85Many authors, both in Hungary and abroad, have reported on experiments carried out to determine the role of sowing time in maize, but the results are often contradictory. This is hardly surprising, since the maize plant exhibits enormous genetic variability and the hybrids created through selection and inbreeding may have very specific requirements as to sowing date. The year effect, too, often complicates the efforts of scientists to provide clear guidance to farmers on the optimal sowing date for each hybrid.
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Establishing biotic stress tolerance of maize (Zea mays L.) by measuring hydroxamic acid contents
107-112Views:201Cyclic hydroxamic acids are the most considerable secondary metabolites in grasses and their main task is to protect these species from pathogens and pests. The cyclic hydroxamic acid content and common smut susceptibility were examined in our experiments. 27 maize hybrids were used for experimental plants in a climate room, where the plants were grown on a nutrient solution. An infiltration method was used for the inoculation of the plants. The total quantity of cyclic hydroxamic acids was determined and the ratio of infected plants and the ratio of inhibition was determined, too. Based on our results, on the basis of all hybrids’ data, the total hydroxamic acid content of the infected plants was higher than in the control. On the level of individual hybrids, only 9 of them had higher cyclic hydroxamic acid content in the case of infection. Increase in cyclic hydroxamic content induced by the fungus in this case is a tool for the fungus to suppress other pathogens and pests. Amongst the hybrids’ cyclic hydroxamic acid contents, significant differences were detected in the control and in the infected treatment, too. The so-called “sweetcorn” hybrids showed high level of cyclic hydroxamic acid content. According to the differences amongst hybrids, homogenous groups were created which groups differed in the case of control and infected treatment, because of the difference in increase of cyclic hydroxamic acid content. The examined hybrids showed different levels of infection and different rate of growth inhibition for the effect of inoculation. According to the infection caused damage hybrids were ranked. Infection caused notable damage for hybrids Prelude, Desszert 73, DKC5276 and DK440.
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Violation prooxidative-antioxidant stability at maize shoots at different level of accumulation of cadmium and nickel
89-94Views:74Joint influence of cadmium and nickel was investigated on the feature of their accumulation by the vegetative organs of 10-days' old maize shoots. It was established that most intensively noted metals are taken in by the roots of shoots in the first 7 hours stressing influencing, while in leaves they appear only after a 7-hour long exposition. It was stated that the absorption process of the noted metals by a root system is carried by two-phase character. The indexes of inner-tissue contamination are calculated. Activating by the cadmium and nickel ions of lipid peroxidation as marker of the stressing influencing, and also was shown the proper increase of intensity of functioning of ascorbate peroxidase as the antioxidant enzyme protection of cell.
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The effect of water supply and crop year on the yield potential of sweet maize (Zea mays L. convar. saccharata Koern.) hybrids with different genotypes
203-210Views:189The 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 making 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. -
Ecotoxicological impact of DON toxin on maize (Zea mays L.) germination
35-40Views:198Fusarium graminearum is one of the most significant arable pathogen in Hungary, and various types of trichothecene mycotoxins (mostly DON, deoxynivalenol) are detected most commonly in cereals (Biró et al., 2011). Fusarium infection and mycotoxin production could not be eliminated, and infected maize by Fusarium sp. cannot be exploited as food, seed, or animal feed. However it can be raw material of biogas production. In this research we would like to investigate the content and effect of the toxin in the end product of biogas production on plant germination. The Fusarium sp. can cause mildew and seedling mortality in seed of maize (Zea mays L.), so we examine the effect of this on germination. In preliminary examination Fusarium sp. was not detected in the bioreactor of the Institute after the retention time (30 day), however it can be assumed that during the hydrolysis of the fungus growth and mycotoxin production also increased exponentially. There were no appropriate tools to detect the toxin in the end product of biogas production so modelling of anaerobic hydrolysis was necessary. The effects of hydrolyzed product for germination were also detected.
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The impact of climatic factors on the relative chlorophyll content and yield of a maize hybrid in a long-term experiment
71-77Views:227The impact of the climatic factors of crop year on the relative chlorophyll content of maize was examined for three years. The examinations were carried out on the Látókép Experiment Site of the University of Debrecen on calcareous chernozem soil in a small-plot, non-irrigated long-term field experiment with strip plot design. In addition to a non-fertilised (control) treatment, nitrogen (N) fertiliser doses were applied as base and top dressing. The 60 and 120 kg N ha-1 base dressing doses were followed by two top dressing doses at the V6 and V12 phenophases.
Averaged over the different fertiliser treatments, SPAD readings increased in all three years as the growing season progressed. The highes SPAD value increase was observed in the average crop year (2017) at the V12 phenophase (11.8), which further increased at the R1 phenophas, by 3,7. No significant Spad value difference was observed between the average (2017) and the dry year (2018) at the V6 growth phase. However, in the wet crop year (2016), the V690 treatment provided the statistically highest relative chlorophyll content (46.8). At the V12 phenophase, the base dressing dose of 120 kg N ha-1+30 kg N ha-1 (V6150) showed to be successful in two years (2016 and 2018), while in 2017, the base dressing dose of A60 was successful. The impact of crop year on relative chlorophyll content can be clearly shown at the R1 growth stage. In all three years, the significantly highest relative chlorophyll content could be achieved at different nutrient levels: A60 in 2016, V6150 in 2017 and V690.
In a wet year (2016), higher yield could be achieved as a result of the 60 kg N ha-1 base dressing and 30 kg N ha-1 at the V6 growth stage (V690) as top dressing in comparison with 2017 and 2018, when higher fertiliser dose (120 kg N ha-1 base dressing and 30 kg N ha-1top dressing at the V6 growth stage) was needed to achieve a significant yield surplus.
Altogether, averaged over the different treatments, the highest yield (12.48 t ha-1) was observed in the wet year, when the relative chlorophyll content was also the highest (50.6).
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Changes of relative chlorophyll content at maize smut inoculated hybrids
55-58Views:271The leaf chlorophyll content analysis is important for several reasons. The natural or anthropogenic stressors directly effect on the chlorophyll content. Through the measurement of the chlorophyll content it is possible to obtain data concerning the physiological status of the plant, moreover the chlorophyll content is closely related to the nitrogen content, so it is linked to photosynthesis and the photosynthetic activity which determine biomass production.
One of the most common symptoms of plant diseases is the larger and smaller interveinal chlorotic areas. These might be local, or expand to the whole plant. There are multiply reasons of chlorosis such as reduction of chlorophyll content, unfavorable effects on the chlorophyll content,disorders regarding function of chloroplasts or ultimately destruction of the chloroplasts. Although such a chlorotic deviancy can contribute to significant losses in photosynthesis; however the underperformance photosynthesis of the sick plants is a more complex process.
As we unambiguously experienced during our investigations on common smut that the infected maize plants most common accompanying symptom was chlorosis on the leaves, so it is especially important to examine how the infection influenced on the chlorophyll content of different hybrids. -
Computer simulation modeling of Leaf Area Index (LAI) in maize
5-8Views:155This study presents a PHP-based model capable of calculating maize leaf area index. The model calculates LAI from emergence to 75% silking. The basis of calculation is represented by the daily average temperature values. The usability of the model was tested using three years' temperature and LAI data series from the values obtained by the weather station set up at the Látókép Experiment Site of the University of Debrecen, Centre for Agricultural Sciences between 1994 and 1996. During the running of the model, it was observed that temperature affects the intensity of leaf development to a various extent.
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Susceptibility of maize hybrids to corn smut diseas
39-42Views:184Corn smut disease is one of the most common maize diseases. In the previous years the disease lost from its importance, however nowadays it is becoming more and more important and widespread. The protection against it encounters great difficulties, therefore it is important to emphasize prevention and resistance based protection. The aim of the research was to investigate under laboratory circumstances the resistance of Hungary’s most commonly cultivated maize hybrids to corn smut disease. Twelve species were investigated. We distinguished two susceptibility groups within the hybrids based on the investigated parameters. The results are intended to assist the protection against corn smut disease and to make a suggestion for the farmers so that they could apply more environmental friendly and economical production.
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Effect of cultivation factors on the yield and yield security of maize
263-265Views:140Cultivation 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 yield 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. -
Examination of the impact of sowing technology models on the ear, constiuent and yield parameters of the yield formation elements of maize hybrids of different genotypes
17-23Views:118Production year 2012 has been characterised by climatic extremities. The weather of this year can be considered very contradictory in terms of maize production. The droughty conditions of the winter and spring months had a negative effect on both germination and starting vigour. The favourable weather of May-July created ideal conditions for intensive growth and generative processes; however the lack of precipitation in August and September had a damaging effect on the development of yield composing elements and grain saturation processes as well. Under such circumstances, the sowing date models caused significant differences in the yield and quality of the hybrids belonging to different growth periods. The growing period of the maize hybrids has been shortened as a result of the unfavourable climatic conditions.
Based on the trial results, it is verifiable that short growing period hybrids can be securely sown in draughty years even with a later sowing date, however using a later sowing date in the case of longer growth period hybrids may result even in a yield loss of 2–3 t ha-1. In the case of early and average sowing dates, with given yearly conditions the hybrids of the observed FAO 370-390 hybrid group provided the best result (12.40 t ha-1, 10.99 t ha-1), while in the case of the third, late sowing date the yield dominance of the FAO 290-350 hybrid group is the most significant (10.08 t ha-1).
The analysis of the yield composing elements found that the P9578 hybrid has the highest shelling ratio, while its cob is the shortest. The P9494 hybrid has a high yield and the highest thousand grain weight, while the DKC 4983 has the longest cob and its thousand grain weight is above 300 g.
The results confirm the fact that DKC 4590 has the highest yield potential and starch content, while in terms of oil and protein content the Szegedi 386 and NK Octet hybrids are the most important.
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Evaluation of reduced tillage technologies in corn production based on soil and crop analyses
47-54Views:160Despite new cultivation methods, the proportion of conventionally cultivated land is still very high in Hungary.
Although these technologies demand more time, labour and fuel, they are still attractive to users because they require less professional skill and simple machinery. In Hungary, conventional tillage methods usually lead to soil deterioration, soil compaction and a decrease in organic content. These side effects have caused gradually strengthening economic and environmental problems.
The technologies for those plants which are dominant on Hungarian arable lands use (winter wheat, maize, sunflower and barley) need to be improved both in the interest of environmental protection and the reduction of cultivation costs.
The Department of Land Use at Debrecen University is cooperating with KITE Sc. to carry out soil tillage experiments at two pilot locations to prove tillage technologies already used in the USA.
The aim of our examination is to adapt new technological developments and machinery, and to improve them on Hungarian soil for local environmental conditions. With these improved machines, the field growing of plants could be executed by less manipulation and better suited to economic and environmental needs. The most significant task is to investigate and improve the conventional cultivation replacing, new soil-protecting tillage technologies, and to apply no-till and mulch tillage systems.
On the basis of the experiments’ survey data, we established that the looseness and moisture content of the soil using reduced tillage is more favourable than after using conventional technologies. The results of no-till and shallow spring tillage are behind those of winter plough or disk ripper cultivation in corn yield and production elements.
To preserve moisture content in the soil, the ground clearing and sowing while simultaneously performing no-till method presents the most favourable results. The surplus moisture gained using no-till technology is equal to 40 mm precipitation.
Regarding the yield of winter wheat we established that the tillage methods do not affect plant yield. Both disk ripper and conventional disc cultivation showed nearly the same harvest results (5.55 or 5.5 t/ha), where the difference is statistically hardly verifiable from the no-till method. From the individual production of corn and the number of plants planted in unit area, calculated results prove that no significant difference can be detected between the production of winter plough and disk ripper technology. Although the yield achieved with the no-till method is less than with the previously mentioned technologies, the difference is only 9-10%. We received the lowest production at shallow spring tillage.
Evaluations have shown a 1.1 t/ha (13%) difference in the yield of maize, between winter tillage and the disk ripper method, in this case the traditional method resulted in higher yield. In winter tillage, the yield of maize was 1.9-2.1 t/ha (23-25%) higher than in the case of direct sowing and cultivator treatments. No significant difference could be noted between the yields of direct sowing and cultivator treatments.
Our research so far has proved the industrial application of reduced tillage methods in crop cultivation technologies. -
Comparison of Variability among Irradiated and Control Inbred Maize Lines via Morphological Descriptions and Some Quantitative Features
70-73Views:73Knowledge of genetic diversity in breeding material is fundamental for hybrid selection programs and for germplasm preservation as well. Research has been done with nine irradiated (fast neutron) and four non-treated inbred lines. The aims of this study were (1) to investigate the degree of genetic variability detected with morphological description (based on CPVO TP/2/2) in these materials, (2) to compare the genetic changes among irradiated and non-irradiated maize inbred lines (based on some quantitative features). The irradiation did not change any of the characteristics clearly in positive or negative way, which can be related to the fact that the effect of induced mutation on genetic structure cannot be controlled. From the irradiated lines we have managed to select plants with earlier ripening times and better phenotypes. We could distinguish 3 main groups by the morphological features; these results match our expectations based on pedigree data. Markers distinguishable on the phenotypic level (e.g. antocyanin colouration, length of tassels) were significant in all lines.
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Comparative analysis of soil analysing datas on different sempling-plots
85-90Views:78Hibrid maize is cultivated on larger plots, therefore the sown areas of hibrid maize are heterogeneous from a pedology aspect. Heterogenity causes problems during tasseling, chemical plant protection and harvest. The heterogenity of sown areas can be compensated by fertilization which is based on soil analysis. We carried out research into change of the soil on four soil types from 1987 to 2005.
There were no significant changes in pH, hydroiodic acidity, CaCO3-content, humus-content on meadow chernozem soil. We detected equalization of salin content in the examined soil layers. There were no significant changes in the measured values on chernozem meadow soil and solonetz meadow soil in 2005. We discoverd equalization of saline content on chernozem meadow soil, but the changes were not as obvious as the changes on meadow chernozem soil. We found salinization in the 30-60 cm soil layer on type meadow soil that may be due to water movement. -
Comparison of RAPD and AFLP Analysis in Some Maize (Zea mays L.) Lines and Hybrids
3-7Views:104The use of molecular markers to enhance plant breeding efforts is being widely studied. DNA-based fingerprinting technologies (RAPD and AFLP) have proven useful in genetic similarity studies. We estimated different maize (Zea mays L.) inbred lines and hybrids originated from mutant ones based on their genetic differences.
We carried out RAPD analysis with different primers and the 707 (CCCAACACCC) and 792 (CAACCCACAC) primers with 50% similarities provided quite good DNA fragments. By applying the DNA based-AFLP technique, we had very dense DNA fingerprinting. We differentiated 15-32 polymorphic bands, the highest number of bands were found in P-T/H-CA (32). AFLP seems to be the more efficient method of comparing genetic similarities/differences among different genotypes. -
Germination and sugar content alteration in maize grain caused by Fusarium contamination
42-44Views:73Healthy and Fusarium affected ears were collected in Fészerlak, Somogy County at the end of vegetation cycle of maize (25-30 August). Each pattern contains 25-25 ears. We compared the samples on the basis of visual image of Fusarium affection. The ears were shelled and two 0,5 kg samples were formed: healthy and Fusarium contaminated. After surface sterilisation the uniform sized seeds were soaked in sterile distilled water for 24 hours and there were germinated for 7 days. The α-amylase activity was measured with Phadebas- α-amylase test. Seeds were extracted one by one three times under reflux using 10 cm3 boiling water for 15 minutes. During our investigation germinating activity was detected to measure glucose, fructose, sucrose content and α-amylase activity. In the first seven days of germination the highest values were detected in control seeds followed by the affected seeds. Our results clearly show that stress conditions applied altered not only the saccharide content but decreased their germinating activity as well in the case of maize grain.
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Development of a New Maize (Zea mays L.) Breeding Program
25-30Views:108Genetic manipulation may not replace any conventional method in crop breeding programs, but it can be an important adjunct to them. Plant regeneration via tissue culture is becoming increasingly more common in monocots such as corn (Zea mays L.). In vitro culturability and regeneration ability of corn decreased as homozigosity increased, which suggested that these two attributes were controlled primarily by dominant gene action. Pollen (gametophytic) selection for resistance to aflatoxin in corn can greatly facilitate recurrent selection and screening of germplasm for resistance at a much less cost and shorter time than field testing. Integration of in vivo and in vitro techniques in maize breeding program has been developed to obtain desirable agronomic attributes, speed up the breeding process and enhance the genes responsible for them. The efficiency of anther and tissue cultures in most cereals such as maize and wheat have reached the stage where it can be used in breeding programs to some extent and many new cultivars produced by genetic manipulation have now reached the market.
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The role of Debrecen maize hybrids in competitive production
19-21Views:70I examined the effects of plant density and fertilisation on the yield of the maize hybrid Debreceni 377 SC, developed by the Agrárgazdaság Ltd., using the 3 year data sequence of a long term experiment set up at the Látókép experimental station of DU Center for Agricultural Sciences in years with average precipitation supply.
Based on the evaluation of my research results, I found that the application of higher plant densities was more favourable in years with average or higher than average precipitation supply. During the examination of fertilisation effects, it was verified that surplus yield was realised in most cases where smaller fertilisation dosage, 120 kg per hectare active substance was applied. -
Examination of the impact of ecological and agrotechnical factors in a maize fertilisation experiment
13-17Views:120The year 2013 was rather extreme breeding year because of the uneven distribution of precipitaion and the summer heat. The experiment was set on with eight different genetic characteristics maize hybrids in 2013. In our study were included different kind of breeding season hybrids. We studied the effect of NKP fertilization and row spacing on the yield. The fertilizer doses are based on 25-year long-term experiment. Compared to control, the N40+PK treatment has also achieved a significant yield increase, although some hybrid of increasing fertilizer doses yield response to loss. The majority of hybrids reached higher yields using the 50 cm row spacing. The water release of hybrids was measured between 21th August and 17th September weekly, at the same time points. The rainy September slowed ripening hybrids and water release, so the grain wet content at harvest showed higher values.
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Field Tests on the Herbicide Tolerance of Various Maize Genotypes
21-23Views:80Investigations 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 effects led to the conclusion that a single dose of the tested herbicides did not cause any damage to the genotypes investigated, with the exception of one inbred line, which was extremely sensitive to herbicides of the sulphonyl carbamide type and moderately sensitive to both rates of dicamba. In many cases, a double dose of the herbicides caused mild or moderate symptoms on the maize lines. -
Role of some agrotechnical elements in the precision crop technology of cereals
241-244Views:129The crop models and precision technology have an important role in the development of winter wheat and maize agrotechnics, which crops have determinative role in Hungarian crop production. The effects of agrotechnical elements (crop rotation, fertilization, irrigation, crop protection, plant density) were studied in our longterm experiments on chernozem soil. Our scientific results proved that the high yields, and good yield stability were obtained in the input-intensive crop models. Maize had lower ecological adaptive capacity than winter wheat. The optimatization of agrotechnical elements reduces the harmful climatic effects so we can increase the yield and yield stability of cereals agro-ecosystems. The yields of wheat varied between 2 and 7 t ha-1 in extensive and 8 and 10 t ha-1 in intensive crop models and the yields of maize ranged between 2 and 11 t ha-1 and 10 and 15 t ha-1, respectively.
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Untersuchungen zur Phosphataufnahme von Zwischenfrüchten bei unterschiedlicher P-Versorgung des Bodens (Investigation of P Uptake of Catch Crops under Different P Supply)
7-14Views:195The 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.
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Molybdenum - accumulation dynamics of cereals on calcareous chernozem soil
81-85Views:134This work is about the molybdenum-accumulation of cereals analyzing soil and plant samples from a field experiment set in
Nagyhörcsök by Kádár et al. in 1991.
In this long-term field experiment different levels of soil contamination conditions are simulated. Soil and plant samples were collected
from the experiment station to study the behaviour of molybdenum.
In this report results of maize, winter wheat, winter barley and soil analysis are presented. The conclusions are as follows:
– Analysing soil samples from 1991 we have found that roughly half of the molybdenum dose applied is in the form of NH4-acetate+EDTA soluble
– Comparing element content of grain and leaf samples we have experienced that molybdenum accumulation is more considerable in the vegetative plant parts
– Winter wheat accumulated less molybdenum then maize in its vegetative parts. Comparing molybdenum content of winter wheat to winter barley we found that the concentration of the element in wheat was lower by half than in the winter barley. It seemed that molybdenum accumulated to the least degree in winter wheat. -
The management and economical aspects of GPS based machine-control and tractor-implement sincronisation
161-167Views:204Precision farming has an array of technological equipment, elements and complete systems which are in themselves suitable to create conditions for efficient farming, to reduce environmental load and to provide farmers with optimal return on their investment.
On the leading edge of my research is to introduce the economic benefits of precision logistic optimization with satellite navigation in wheat and maize harvesting. My hypothesis, claiming that a well-organized system can increase the number of working days by 4 days per harvesting season in maize, and 2 days in wheat crop. If the farmer makes contract works for harvesting it means for him 2 or 4 days extra work by using the precision farming technologies with satellite communication system. Overall, as pertains to wheat and maize harvest seasons, yearly revenues can be increased by 7 760 000 HUF. I would like to introduce that the precision technologies increase combine costs by merely 5.4% which can be return in the first year of using.
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Examination of drought stress of two genotype maize hybrids with different fertilization
53-57Views:125In the growing season of 2019, we analysed stress resulting from climatic factors on maize hybrids of different genotypes, with the aim of gaining a better understanding of the physiological responses of each hybrid, which might support the elaboration of a cost-effective irrigation plan.
Our experiments were carried out at the Látókép Experimental Station of the University of Debrecen on calcareous chernozem soil in a small-plot long-term field trial with strip plot design. In the scope of the experiment, N-fertilizer doses were applied as basic fertilizer and top-dressing in addition to the non-fertilized (control) treatment. The 60 and 120 kg N/ha doses applied as basic fertilizers in the spring were followed by top-dressing in the V6 phenophase with a +30 kg N/ha dose. Measurements were carried out with the involvement of the Renfor early (FAO 320) and Fornad (FAO 420) late maturity hybrids-
The stomata of the plants became more and more closed with the progression of the phenological phases; their stomatal conductance decreased. However, the hybrids responded differently to environmental stress. In the case of the Renfor hybrid, the highest conductance (669 mmol/m2-s) was recorded in the V12 phenophase with the 150 kg N/ha treatment. The stomata were more open due to the high turgor pressure, allowing plants to evaporate properly. The plant was in its worst physiological condition on 2nd July, at the time of the appearance of the last leaf in the case of the 120 kg N dose (224 mmol/m2-s). The value measured in the V12 phenophase has already shown that the stomata were closing due to the self-regulating system of the plant. It would have been necessary to dispense irrigation water following the measurement. This confirms the finding that water stress can be prevented by measuring stomatal conductance.
In the case of the Fornad hybrid, stomatal conductance was the highest on 12th June (630 mmol/m2-s) in the 90 kg N/ha treatment and it was the lowest (183 mmol/m2-s) in VT (emergence of the last leaf) phenophase in the 60 kg N/ha treatment. In this case, the appropriate time for applying irrigation water would have been early July, when the conditions for the plants were still adequate. Subsequently, the stomata began to close due to a reduction of the water resources available to them.
There was a significant correlation between soil moisture and stomatal conductance, as well as between temperature and stomatal conductance.