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  • Effects of the cropyear and the agronomical factors on agronomical elements of different sweet corn (Zea Mays L. convar. saccharata Koern.) genotypes in long-term experiment
    105-110
    Views:
    241

    In the crop season of 2010 (rainy year), we studied the effect of three agrotechnical factors (sowing time, fertilization, plant density) and four different genotypes on the agronomical characteristics of sweet corn on chernozem soil in the Hajdúság. The experiments were carried out at the Látókép Experimental Farm of the University of Debrecen. In the experiment, two sowing dates (27 April, 26 May), six fertilization levels (control, N30+PK, N60+PK, N90+PK, N120+PK, N150+PK) and four genotypes (Jumbo, Enterprise, Prelude, Box-R) were used at two plant densities (45 thousand plants ha-1, 65 thousand plants ha-1). The amount of precipitation in the season of 2010 was 184 mm higher, while the average temperature was 0.8 oC higher in the studied months than the average of 30 years. Weather was more favourable for sweet maize at the first sowing date, if we consider the yields, however, if we evaluate the agronomical data and yield elements (number of cobs, cob length and diameter, the number of kernel rows, the number of kernels per row) it can be stated that the size of the fertile cobs was greater at the second sowing date due to the lower number of cobs. The largest number of fertile cobs was harvested in the case of the hybrid Enterprise (72367.9 ha-1) in the higher plant density treatment (65 thousand ha-1) at the fertilization level of N120+PK when the first sowing date was applied. The largest cobs were harvested from the hybrid Box-R (cob weight with husks: 516.7 g, number of kernels in one row: 45.7) at the lower plant density (45 thousand plants ha-1) in the second sowing date treatment. Cob diameter and the number of kernel rows were the highest for the hybrid Prelude.

  • Impact of fertilization on production capacity and reaction to fertilization in maize hybrids
    42-46
    Views:
    157

    New varieties and fertilization have significantly increased yields of maize in recent decades. It has to be taken into account however that the interactions and the balanced combination of cropping factors (ecological, biological and agrotechnical) are the main factors which determine yields. Weather conditions were rather unfavourable during the last decade. Extreme weather conditions occurred due to global warming; 6 of 10 years were plagued by drought. Consequently yields increased from 10-20% to 30-50%. In view of varieties the situation is advantageous, maybe the supply of hybrids is too high, nevertheless those hybrids need to be selected which are particularly well adjusted to the ecological conditions. Many technologies can be applied which vary according to intensity, but the balanced combination of cropping factors should be secured on the basis of the hybrid’s intensity. Among agrotechnical factors the compensation of nutrients and technological conditions were inadequate. These days farmers only use nitrogenous fertilizers consequently they significantly decrease the easily available P and K content of the soil which in long term leads to the deterioration of the soil’s productivity. The technological background is therefore important, because sufficient yields can only be expected if agrotechnical operations are carried out in the right time and quality. 

  • The changes of the most important quality parameters of szegedien triticale cultivars in long-term fertilization trials
    21-26
    Views:
    539

    We were monitoring the quality changes of 2 triticale cultivars from Szeged (GK Rege and GK Szemes) in Fülöpszállás, Hungary, in a longterm fertilizer trial in 2012/2013 and 2013/2014. The following fertilizer combinations were used: untreated control, single applied N and single applied PK, 30 and 60 kg ha-1 N or PK, and N and PK together in 30:30, 60:60 ha-1 ratio. We measured the following quality parameters: kernel hardness, crude protein content and farinograph quality number for wholemeal flour.

    Based on the results, the N fertilization treatment was beneficial to the tested triticale culticars in terms of kernel hardness and protein content as both indicators increased. The efficiency of the treatment was proportional to the N dose rate. On the other hand, the applied PK treatment decreased the kernel hardness and crude protein values. On these two parameters, the PK free, and high N dosage treatment (N60P0K0) had the most positive effect. However, the single applied N dose had no significant effect on farinograph quality numbers of the wholemeal flours, but PK dose had significantly positive impact on the tested cultivars. The N30P30K30 treatment resulted in the highest farinograph quality number, thus the low PK and low N combination was the most efficient treatment. The correlation analysis of the tested quality parameters showed positive correlation (0.9965***) between kernel hardness values and crude protein contents. Nevertheless, we found strong negative correlation between kernel hardness values and the farinograph quality number of the wholemeal flours (-0.9720***), as well as in the case of crude protein contents and farinograph quality number of the wholemeal flours (-0.9796***).

  • The effect of NPK treatments on the Cu and Fe content of winter wheat (Triticum aestivum L.)
    31-34
    Views:
    533

    In this study the effect of N, P and K nutrients on the Cu and Fe content of winter wheat (Triticum aestivum L.) grains was investigated in a long-term fertilization experiment set up in Nagyhörcsök. Samples were also harvested from four experimental stations of the Hungarian national long-term fertilization trials. These are the following: Bicsérd, Iregszemcse, Karcag, and Putnok. Plant samples were collected in 2005 which was very wet. Our results from Nagyhörcsök were compared with the Cu and Fe content of samples which were harvested from control plots of other experimental stations. The Cu and Fe content of grain samples were measured using inductively coupled plasma mass spectrometer (ICP-MS) followed by digestion with HNO3-H2O2 solution. All data were subjected to ANOVA, and when significant differences (P<0.05) were detected, Duncan’s test was performed to allow separation of means.

    The main conclusions are as follows: Cu and Fe content of wheat grains was higher and higher in every NPK treatments. Samples were harvested from the control plots of Iregszemcse and Bicsérd have higher Cu content than the treated samples from Nagyhörcsök.

  • Effect of agrotechnical factors on the activity of urease enzyme in a long term fertlization experiment
    43-48
    Views:
    392

    The soil is a natural resource, the fertility preservation is an important part of the sustainable development. We have to monitor the transformation dinamics of the organic nitrogen-containing substances, to get accurate information about the changes of the nitrogen cycle in the soil.

    Physical and chemical properties of the soil and the microorganism effect on the organic matter in the soil – in addition to the composition of organic matter. Wide variety of extracellular enzymes are present in this decomposition. These enzymes help in the transformation of the macromolecules to transforming low molecular weight compounds so they will be available during the assimilation.

    The urease enzyme, catalyzes the hydrolysis of urea to CO2 and NH3. The urease is widely spread in the nature, it is present in the microorganisms, plants and animals.

    We found that the soil moisture content, the rotation and the fertilization affect to the amount of urease in spring. Furthermore, we get significant difference between the irrigated and non irrigated samples in the second period of the year. Based on our results we can state that the activity of urease was higher in spring 2014.

    The objective of our study was to present how the different agronomic factors affect on the activity of urease in a long term fertilizationexperiment.

  • Study of factors controlling the amount of 0.01 M CaCl2 extractable Norg fraction
    437-449
    Views:
    332
    The use of new methods describing the “readily available” nutrient content of the soil is spreading on a global scale. The 0.01 M CaCl2 extractant is a dilute salt solution in which the easily soluble inorganic (nitrate-N and ammonium-N) and organic N fractions, P, K and micronutrients are also measurable. The 0.01 M CaCl2 has been tested in the University of Debrecen, Institute of Agricultural Chemistry and Soil Sciences since the 90’s. The results of the researches related to organic N fraction, performed in the last decades, and the results of the present study (originating from the long-term experiment of Karcag, 2007–2009) can be concluded as follows:
    The measurement of easily soluble and oxidizable organic nitrogen (Norg), besides inorganic fractions, could improve the nutrient management.
    The amount of the Norg fraction is determined by the soil conditions, therefore it is considered to be a site-specific parameter.
    Management practices and cropyear affect the amount of Norg as well. The present research confirmed that, the effect of fertilization on the amount of Norg can be explained by the changing of the yield (related to total biomass production), while the effect of cropyear is related to the differences in mineralization circumstances and yield as well.
    The measurement of the Norg fraction is increases the accuracy of N-supply, therefore it could prevent the environmentally harmful excess N application as well.
  • Fertilisation Effect on Quantity of 0.01 M CaCl2 Soluble N-Forms in a Long-Term-Small-Plot Experiment
    166-170
    Views:
    200

    long-term experiments have an opportunity to investigate the effects of fertilization and plant nutrition. The paper reports the results achieved in the 39th years of a long-term-small-plot fertilisation and liming experiment set up on acidic sandy brown forest soil in the Nyírség region. From the 32 treatment, four replications, altogether 128 plot experiments with 10 treatments are summarized. We took samples after harvest of triticale, in August.
    We used a reliable method (segmented continuous flow analysis) to determine different (easily mobilized - 0.01 M CaCl2 soluble) N-forms of soil. The 0.01 M CaCl2 soluble inorganic and total N content and the UV digestable organic-N form of soil were determined by this method.
    The results are summarized below:
    – The mineralized-N (Nmin.) content of soil increased with dose of nitrogen treatment. Liming treatments increase the amount of Nmin.
    – The maximum content of easily mobilize organic-N-fraction was found in the upper (0-20 cm) layer. This fact due to the large amount of crop and roots.
    – Changing of content of 0.01 M CaCl2 soluble total-N-forms due to N doses.
    – The ratios of these N forms are variable. It is very important that the content of organic N fraction is not negligible and this fraction plays a main role in the plant nutrition.

  • Effect of fertilization on the potentially mineralize N forms of soil of long term field experiment was set in an acidic sandy soil
    20-24
    Views:
    466

    The aim of this paper was to provide further information about the nitrogen mineralization processes of soil. A modified incubation technique was applied to establish the amount of easily soluble mineral and organic N forms during the incubation period. An acidic sandy soil was used for incubation, which was sampled from the „Westsik” long-term field experiment. The incubation was carried out on fifteen selected soil samples which were received different treatments since the experiment was set up. 
    From the obtained results, the amount of potentially mineralizable N and the mineralization rate constant were determined. Results of chemical analysis and biological interpretation of results are discussed.

  • Energy crops on less favoured (alkaline) soil
    115-118
    Views:
    258

    The reduction in fossil energy and row material sources induces growing demand for renewable resources. The growing demand for herbal raw materials has land use impacts as well. One way to reduce the conflict between the food and energy crops can be the utilization of less favored areas by growing energy crops. Among the potentially available areas for this purpose the salt affected soils (SAS) occupy a significant territories. SAS with structural B-horizon (meadow solonetz soils) represent the most wide spread group of SAS in Hungary. About half of these soils have been reclaimed and used as arable land and the remaining 50% are used as grassland. Sweet sorghum production for manufacturing of alcohol production was investigated in a long term amelioration and fertilization experiment on a salt affected soil (meadow solonetz). By means of regression analyzes the effect of sodium content of the soil and increasing mineral fertilizer doses were studied. According to the multiple regression analysis only the effect of nitrogen fertilizer was significant. On the solonetz type salt affected soil the effect of water soluble salt content of the soil was not significant, but there was a closer correlation between the ammonium-lactate sodium content and the yield of sweet sorghum. The maximum green mass was 45–50 t ha-1, in the case of low Na content and high level of nitrogen fertilization.

    In order to quantify the potential yield of natural grass vegetation the relationship between the soil forming processes and the grass vegetation
    was investigated. Beyond the different forms of Na-accumulation, the spatial pattern (mosaic-like characteristic) is also an inseparable feature of salt affected soils. The difference in the water regime, caused by the micro-relief is the main cause of variability. The run-on water keeps the deeper parts of the catena position wet longer. The wet situation causes more intensive leaching. In the low-laying parts of salt affected soils species preferring wet situations (mainly Alopecurus pratensis) are in majority. On the higher parts of the micro-relief species tolerating dry situations (mainly Festuca  pseudovina) are dominant. The yearly grass production of low laying areas can be 4–7 t ha-1 but because of prolonged wet  conditions the grass is not grazed and mowing can only be in old state. This old grass is not proper for feeding, but it may be suitable as energy plant. 

  • Rye plant parameters in the Westsik crop rotation experiment
    39-45
    Views:
    246

    Our research work was carried out in the Westsik crop rotation field experiment in 2018. The main research purpose was to analyse the effect of the different organic and chemical fertilizers on parameters of rye. Our results revealed some differences between the different fertilization methods. One spike weight, grain weight of one spike, rye plant height, rye plant weight per m2 and 1000 seed weight in crop rotations VII, XV and VIII were different from the data of all crop rotations. This finding can be explained by the fact that crop rotations VII and XV were non-fertilized, only 23.3 t ha-1 straw manure (VII) or green lupine manure was applied as a second crop (XV). In addition, crop rotation VIII consists of four parts where we apply chemical fertilization with green lupine manure as a main and second crop. There is a positive close correlation between rye plant height and other studied characters (rye plant weight per m2, spike length, weight of one spike, grain weight per spike, spike weight per m2, grain weight per m2 and 1000 seed weight).

  • The imact of crop rotation and fertilisation on the SPAD values of winter wheat on chernozem soil in a long-term experiment
    123-126
    Views:
    263

    We have carried out our outdoor field experiments at the Látókép Experimental Farm of the CAS of the University of Debrecen in the cropyear of 2012/2013 on chernozem soil in a long-term experiment. We have studied the effects of two different preceding crops (sweet corn, sunflower) on the development of the SPAD values of wheat varieties of different genotypes in the cases of control, N60+PK and N120+PK fertilizer treatments. According to our research results, we have concluded that the preceding crop, the fertilizer application and the variety selection influenced the SPAD values. According to our data, we have measured higher SPAD values after sweet corn preceding crop, the standard deviations were in a smaller range in the case of the studied varieties. After sunflower preceding crop, smaller averages were experienced with wider standard deviation range. In the case of favourable preceding crop, the differences between the varieties are more pronounced than in the case of unfavourable preceding crop. The maximal SPAD values were measured in milky ripening in the case of N120+PK fertilizer treatment.

  • Effects of soil cultivation and environmental changes on maize yield
    97-100
    Views:
    306

    We evaluated the relationships among soil cultivation and other agrotechnical factors (fertilization, number of plants and hybrid) within the framework of a multifactorial long-term experiment set at the Látókép Experimental Site of the Centre for Agricultural Sciences of the University of Debrecen in mid-heavy chalcareous chernozem soil based on a long-term experiment conducted for a 5-year period (2002–2006).

    Based on the evaluation of soil cultivation by the average of treatments, it may be assessed that spring ploughing (8.204 t ha-1) provides more favourable conditions to the stand compared to spring shallow cultivation; however, this did not result in a significant difference. Spring ploughing considerably increased the yield of hybrid FAO 300 in dry years, whereas it considerably increased the yield of hybrid FAO 400 in favourable crop years. A stand of 70 thousand stems/ha provided the higher yield result in both soil cultivation types. It was sufficient to use a fertilizer dose of 120 kg N ha-1 for economical production.

  • Evaluation some important microbiological parameters of the carbon cycle in chernozem soils profiles
    33-39
    Views:
    410

    Some chemical and microbiological properties of the carbon cycle were investigated in three chernozem soil profiles. The soil profiles originated from a long term fertilization experiment (potato) of the University of Debrecen, Látókép, Kryvyi Rig Botanic Garden (grassland) and a large-scale farm (sunflower) of Ukraine. The results of the organic C-content, total number of bacteria, microscopical fungi, cellulose decomposing bacteria, CO2-production, microbial biomass carbon and saccharase and dehydrogenase activities were compared and evaluated with the help of correlation analyses. Close correlation was found between the organic carbon content and the number of microscopical fungi,, saccharase and dehydrogenase enzymes’ activities, as well as close correlation was found between the dehydrogenase activity and microbial biomass-C and saccharase activity.

  • 15N-Tracertechnik in der Pflanzenbauforschung
    3-9
    Views:
    159

    Issues of nitrogen are still of particular importance in crop sciences. 15N-tracer are used to identify the N dynamics in soils and the N transfer between soil and plant. This tool is also helpful in clarifying fertilization problems.
    This article points out the special requirements for the application of stable 15N-isotops in agri-chemical research. Designs and results of selected laboratory experiments, examples of one-year field experiments, and a 15N long-term trial are represented in detail. The given literature refers to detailed results of diverse 15N publications in the system soil – fertilizer – (animal) – crop.

  • Effect of tillage practices, fertilizer treatments and crop rotation on yield of maize (Zea mays L.) hybrids
    43-48
    Views:
    501

    This research was conducted at the University of Debrecen Látókép Research Station and is part of an ongoing long-term polyfactorial experiment. The impact of three tillage systems (Mouldboard plowing-MT, Strip tillage-ST, Ripper tillage-RT) and two levels of fertilizer treatments (N80 kg ha-1, N160 kg ha-1) along with a control (N0 kg ha-1) on the yield of maize hybrids (Armagnac- FAO 490 & Loupiac-FAO 380) cultivated in rotation with winter wheat was evaluated during a two-year period (2017–2018).

    Amongst the three tillage treatments evaluated, ripper tillage (RT) had the highest average yield (10.14 t ha-1) followed by mouldboard tillage (MT) and strip tillage (ST) with 9.84 and 9.21 t ha-1 respectively. Yield difference between RT and MT was not significant (P>0.05), as compared to ST (P<0.05). Soil moisture content varied significantly with tillage practices and was highest in ST, followed by RT and MT (ST>RT>MT). Yield of RT was 7–9% higher than MT in monoculture plots, while MT reign superior in biculture plots (monoculture: RT>MT>ST; biculture: MT>RT>ST).

    A positive interaction between tillage and fertilization was observed, with higher yield variation (CV=40.70) in the non-fertilized (N0) plots, compared to those which received the N80 (CV=19.50) and N160 kg ha-1 (CV=11.59) treatments.

    Incremental yield gain from increase fertilizer dosages was significantly higher in monoculture, compared to biculture. There was no significant difference in yield between N160 and N80 in the biculture plots (12.29 vs 12.02 t ha-1). However, in monoculture plots, N160 yield was 23% higher than the N80 kg ha-1 (N160=11.74 vs N80=9.56 t ha-1).

    Mean yield of maize in rotation with winter wheat was 28% (2.47 tons) higher than monoculture maize. The greatest benefit of crop rotation was observed in the control plots (N0) with an incremental yield gain of 4.39 tons ha-1 over monculture maize (9.92 vs 5.43 t ha-1).

    Yield increased with higher fertilizer dosages in irrigated plots. Fertilizer application greatly increased the yield of maize and accounted for 48.9% of yield variances. The highest yield (11.92 t ha-1) was obtained with N160 kg ha-1 treatment, followed by N80 kg ha-1 (10.38 t ha-1) and N0 kg ha-1 (6.89 t ha-1) respectively.

    Overall mean yield difference between the two hybrids was not statistically significant, however, yield of FAO 380 was 3.9% higher (9.06 vs. 8.72 t ha-1) than FAO 490 in monoculture plots, while in biculture plots, FAO 490 was 4.1% higher than FAO 380.

    Average yield in 2018 was 13.6% (1.24 t ha-1) higher than 2017 for the same set of agrotechnical inputs, thus, highlighting the significant effect of cropyear.

    Armagnac (FAO 490) cultivated in rotation with winter wheat, under ripper tillage and N80 kg ha-1 is the best combination of treatments for optimum yield.

  • Comparative study of a winter wheat variety and hybrid sown after different pre-crops on chernozem soil
    63-69
    Views:
    494

    Wheat production is a determining branch within Hungarian crop production (produced on nearly one million hectares). Weather anomalies caused by climatic change confirmed the importance of the biological background (variety, hybrid) in wheat production. The adapting ability and reaction of different wheat genotypes towards nutrient supply were studied in a long-term field experiment on chernozem soil type in the case of different pre-crops (sunflower and maize). According to the experimental results of the vegetation of 2017/2018, the yield of the variety Ingenio sown after the sunflower as previous crop ranged between 4168 and 8734 kg ha-1, while in the case of maize as previous crop, this value ranged between 2084 and 7782kg ha-1, depending on the applied nutrient supply level. The studied genotypes produced rather significant yield surplus as a response to the application of mineral fertilization (4.6–5.1 t ha-1 after sunflower and 5.7–6.3 t ha-1 after maize). Optimal mineral fertilizer dosage was determined by both the genotype and the pre-crop. N-optimum values of wheat genotypes was determined using regression analysis. In the case of the variety Ingenio sown after sunflower, the optimum range was N144-150+PK, while after maize, it was
    N123-150+PK, respectively. For the hybrid Hyland, these optimum ranges were N114-120+PK, just as N150-153+PK, resp. The application of optimal mineral fertilizer dosages improved water utilization of the studied wheat genotypes to a significant extent. WUE values of the control, unfertilized treatments ranged between 4.1–8.3 kg mm-1, while in optimal fertilizer treatment, it ranged between 15.5 and 17.4 kg mm-1.

  • Evaluate the nutritional reaction at winter wheat after different forecrops
    77-80
    Views:
    234

    Our field researches took place on the Látókép test farm of Agricultural Science Centre of University of Debrecen, Centre for Agricultural and Applied Economic Sciences, in long-term experiment, on calcareous chernozem soil, in growing season of 2014/2015. In our experiment we examined the fertilizer reaction and the yield of different winter wheat genotypes (GK Öthalom, GK Csillag, Mv Csárdás, Mv Toldi) with grain maize and sweetcorn forecrops. According to our results, the sweetcorn forecrop strongly affected the yield. In the average of the fertilizer treatments and the varieties, after sweetcorn forecrop 6.9 t ha-1, after grain maize forecrop 5.4 t ha-1 average yield was gained. According to our data, the fertilizer reactions of the varieties were significantly different.

  • The irrigation influence under the soil, microclimate and plants in maize from Crişurilor Plain
    180-186
    Views:
    278

    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 maize, sunflower, soybean, sugarbeet, potato and alfalfa 1st year and 0 – 100
    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.

  • The effect of different fertilizer treatments on the sulphur and protein content of wheat
    73-76
    Views:
    493

    In this study the effect of N,P and K nutrients on the S and protein content of wheat grains was investigated in a long-term fertilization experiment set up in Nagyhörcsök. The calcareous chernozem soil having the following characteristics: pH (KCl): 7.3, CaCO3: 4.27%, humus: 3.45%, Al-soluble P2O5 and K2O: 60–80 and 180–200, KCl- Mg: 150–180, KCl+EDTA-soluble Mn-, Cu- and Zn-content: 80–150, 2–3 and 1–2 mg kg-1. The experiment had a split-split-plot design with 40 treatments in 4 replications. Plant samples were collected from 2002 and 2004. 2002 was a drought year while 2004 was very wet.
    The main conclusions are as follows:
    – The sulphur and protein content were than the control higher in every NPK treatments.
    – The sulphur and protein content of the wheat grains were higher in 2004 that had a lot of rain than in 2002 that had drouht.

  • Examination of drought stress of two genotype maize hybrids with different fertilization
    53-57
    Views:
    337

    In 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.

  • Examination of the impact of ecological and agrotechnical factors in a maize fertilisation experiment
    13-17
    Views:
    225

    The 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.