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  • Measurement of the degradation of abandoned turf
    145-149
    Views:
    225

    With the decreasing number of grazing livestock in Hungary, the role of the turf cultivation is also significantly decreasing. The proportion of the under- and non-utilized turf is increasing. In the research conduced at the University of Debrecen, IAREF Research Institute Karcag, we studied four types of turf utilization in three replicates on a salt field with timothy grass. We determined the flora composition of the experimental area, measured the soil moisture and the carbon-dioxide content of the soil.

  • Evaluation of striptillage and conventional tillage in maize production
    37-40
    Views:
    174

    Tillage changes soil properties and the way how the environment affects those properties. Soil properties and environment determine the rate of water movement in liquid and gaseous form into and out of soil. Based on the experimental database of the Institute of Land Utilisation, Regional Development and Technology of the University of Debrecen, Faculty of Agricultural and Food Sciences and Environmental Management and the KITE PLC, various cultivation systems were examined with maize (Zea mays L.) as indicator plant in Jász-Nagykun-Szolnok county. The sample area can be found in the outskirts of Kenderes on a meadow chernozem soil. On the examined plot, strip-tillage, subsoiling and moldboard ploughing were performed, each on 4.5 ha, respectively. The purpose of the present study is to compare these cultivation systems according to the soil- and maize kernel moisture content and to the yield based on the years of 2012 and 2013.

  • The main influencing factors effecting the yield of maize
    137-141
    Views:
    118

    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.

  • Effect of agrotechnical factors on the activity of urease enzyme in a long term fertlization experiment
    43-48
    Views:
    154

    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.

  • The effect of sowing date and plant density on the yield of maize (Zea mays L.) under different weather conditions
    205-208
    Views:
    324

    Maize has high productivity and produces huge vegetative and generative phytomass, but this crop is very sensitive to agroecological (mainly to climatic, partly to pedological conditions) and agrotechnical circumstances. In Hungary, maize is grown on 1.1–1.2 million hectares, the national average yields vary between 4–7 t ha-1 depending on the year and the intensity of production technology. The longterm experiment was set up in 2015–2016 on chernozem soil in the Hajdúság (eastern Hungary). The maize research was set up on chernozem soil at the Látókép MÉK (Faculty of Agricultural and Food Sciences and Environmental Management) research area of the University of Debrecen. We examined the following commonly used hybrids of Hungary: SY ARIOSO (FAO 300), P9074 (FAO 310), P9486 (FAO 360), SY Octavius (FAO 400), GK Kenéz (FAO 410), DKC 4943 (FAO 410). The experiment was set up in three different plant densities. These were 60, 76, 90 thousand plant ha-1. The experiment was set up with three different sowing dates, early, average and late sowing. The yield was measured using a special plot harvester (Sampo Rosenlew 2010), measuring the weight of the harvested plot and also taking a sample from it. As a next step, we calculated the yield (t ha-1) of each plot at 14% of moisture content to compare them to each other. We evaluated the obtained data using Microsoft Excel 2015.

  • The Effect of Soil Coverings on Cellulose Decomposition Activity of Sandy Soil
    15-20
    Views:
    84

    The purpose of our experiments is to discover the effect of different soil cover matter (agroszövet and black polyethylene) on actual (under field circumstances) and potential (under laboratory circumstances) cellulose decomposition activity. In our field research, the Unger-test was used, and in laboratory research, the Petkov-Markova method was applied. In the first year of the experiment (2000) actual cellulose decomposition activity was significantly higher in covered than in the uncovered soil both in spring and autumn. The difference between the two treatments was significant only in spring. In the spring of 2001 black polyethylene showed significantly the lowest, activity, while in autumn the agroszövet (a porous black polyethylene) showed significantly the highest activity. In the autumn of 2001 the soil covered by black polyethylene gave non-significant,and the soil covered by agroszövet gave a significant higher activity value than the control. Averaging the two experimental years (2000-2001), the actual cellulose decomposition activity was significantly higher in covered soils both in spring (with 30-39%) and in autumn (with 34-69%). Moreover, in autumn a significantly higher value was detected under agroszövet than in any other treatment. The difference between the effect of treatments was not significant. In 2000, the potential cellulose decomposition activity was the highest in soil covered by agroszövet in spring, but in autumn higher activity value was detected in every covered soil than in the control. In the spring of 2001, every covered soil showed a lower, but in autumn a higher, potential cellulose decomposition rate than the control. The activity decreased significantly 27 (agroszövet) and 45 (black polyethylene) percent in spring, and increased no- significantly 8 (agroszövet) and 4 (black polyethylene) percent in autumn. During the two experimental years, we observed on average lower potential cellulose decomposition activity (15-60%) in spring and a higher one (14-43%) in autumn. Neither was significant. The dynamic of potential cellulose decomposition activity averaging 2000 and 2001 showed a slight, the actual cellulose decomposition activity an explicit non-significant upward tendency. There was a strong (r=0,189) correlation obtained between the actual and potential cellulose decomposition activity of soil, and a medium-strong (r=0,673) relationship between the soil moisture content and actual cellulose decomposition activity.

  • Land use, water management
    81-87
    Views:
    263

    Due to the prognosed population increase to 9.2 billion people by 2050, the world’s crop production does not have any other chance than to increase production. This demand is a huge challenge for agriculture. Based on the forecasts, the growth rate of production of the main cereals will decrease as a result of the effect of soil, water, the increasing fuel and fertiliser prices and the impacts of climate change. Methods ensuring sustainability have to be preferred. Precision agriculture is the most effective method of crop production. We have to apply minimum cultivation in order to protect the soil surface, maintain its moisture content and increase its water reception ability. In addition to the localised use of fertiliser, sowing seed, irrigation and pesticides, it is also important to apply them in a targeted way on the basis of plot imaging. The use of the new technology results in significant cost saving and it could also reduce environmental load.

  • Technological development of sustainable maize production
    83-88
    Views:
    160

    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 eight ha field. The size of one plot was 206 m2, this it was a half-industrial 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 per ha.
    In Hajdúszoboszló, in 2016 the amount of rainfall from January to October was 605 mm, which was more than the average of 30 years by 160 mm. The yield of hybrids without fertilization changed between 9.63–11.6 t ha-1 depending on the number of plants.
    The six tested hybrids is 10.65 t ha-1 in the average of the stand density of 60, 70 and 80 thousand plants per hectare without fertilization, while it is 12.24 t ha-1 with N80+PK fertilizer treatment. That increase in the yield is 1.6 t ha-1, it is significant.
    Da Sonka hybrid is sensitive to weather, it is able to produce 6 t ha-1 additional yield in case of favourable condition. However, it has a low stress tolerance. The most stable yields were observed at Kamaria and Pioneer hybrids. The effect of vintage is also an important factor on the yield. In average, the yield of maize was 6.81 t ha-1 in 2015, which was a drought year and 11.86 t ha-1 in 2016 that was a favourable year.

  • Agronomical and economic evaluation of various cultivation systems on meadow soil
    103-106
    Views:
    124

    The requirements and objectives of cultivation are in constant change. There are different cultivation aims if the objective is soil protection, the prevention of its moisture content or on areas with different precipitation supply or production site endowments. Based on the experimental database of the Institute for Land Utilisation, Regional Development and Technology of the University of Debrecen, Centre for Agricultural and Applied Economic Sciences and the KITE Plc., the various cultivation systems in Hajdú-Bihar country were examined with maize as indicator plant. The sample area can be found in the outskirts of Biharnagybajom on meadow soil. On the examined plot, spring strip basic cultivation, loosening and autumn ploughing were applied on 15-15-15 ha, respectively. At the time of taking undisturbed soil samples, soil conductivity measurements were also performed with a Penetronik penetrometer. Undisturbed soil samples were taken from each treatment before sowing (on 5th April 2012). The yield obtained in the strip cultivation treatment increased that of the ploughing and the loosening technology. The economic indexes are the most favourable in the strip cultivation.

  • Evolution of some components of agroecosystems productivity from Vinga Plain in water stress situations
    174-179
    Views:
    80

    The researches are inscribed on line of substantiation of durable agricultural system, having main objective the prominence of
    quantitative and qualitative modifications made on agro-system level under the effect of no-tillage system for wheat, maize and soybeans.
    The experimental field is placed on a cambium chernozem, with a medium content of clay, dominant in the Prodagro West Arad agrocentre
    and representative for a large surface in the Banat-Crisana Plain.
    The passing to no-till system change the structure of technological elements, through less soil works, so the impact on agro-system is
    different comparing with conventional tillage, first less the intervention pressure on agro-system ant secondly appears new interactions, new
    equilibriums and disequilibriums.
    Considering the evolution of soil humidity, the observations made monthly (by taking soil samples and laboratory determinations) for
    the three cultures showed that in the no-till system, there are more uniform values in the soil profile, and in the variants where the deep work
    of soil was made it could be observed a low increase of the water volume in the soil.

  • The relationship between the nutrient supply and the yield of maize hybrids with different genetic traits on chernozem soil in variant years
    27-31
    Views:
    214

    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 significant 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.

  • Examination of compost maturity using reflectance
    29-34
    Views:
    227

    Composting is one of the most popular recycling processes for organic waste. Composting plays an important role in waste and by-product management and is becoming increasingly important in both sustainable energy management and circular economy. Composting transforms organic matter to produce a safe and stable by-product (compost) that can be applied to arable land in a similar way to fertilizer. Physical, chemical and biological methods can be used to monitor the process and to determine the maturity of the compost, as spectrometric/spectroscopic methods play an important role in the analysis of different environmental samples.

    Our aim was to (1) non-destructively detect the effects of different additive ratios on the spectral properties of the composting process and the spectral data of different compost mixtures, (2) to find the wavelength ranges of the reflectance curve (inflection points) sensitive to compost maturity, (3) to determine the correlation between the inflection points and the chemical and physical parameters measured in compost by conventional methods.

    The mixture of broiler and hen manure and zeolite was composted 62 days in windrow composting. In the composting experiment, the moisture content and temperature (°C) were measured every three days and compost samples were taken and in 10% destillated aquaeous suspension were measured the pH and electrical conductivity (mS cm-1). Compost samples dried to mass stability were spectrally analyzed in the wavelength range 400–1000 nm with AvaSpec 2048 spectrometer.

    Based on the results, the reflectance of mature compost were smaller in the last days of composting than the reflectance values of day 0 samples, thus compost maturity can be detected spectral in the VIS-NIR wavelength range. For the tested compost prisms, the reflectance of each sampling day shows a constant slope, with a significant overlap of the reflectance curves up to 400–700 nm wavelength range, and there was a breakpoint in the 700–750 nm wavelength range which was proved by binary encoding.

  • Examination the effects of different herbicides on the soil microorganisms of a calcareous chernozem
    121-126
    Views:
    92

    Pesticides play a key role in fighting weeds, pests and parasitic fungi. According to surveys, pests reduce the yield of agricultural crops by 35% worldwide. Pests, fungi and weeds account for 14%, 12% and 9% yield loss, respectively (Gáborjányi et al., 1995). Chemicals have contributed to increasing and maintaining the yields of crop production for decades. Today, agricultural production (in spite of many efforts) is unthinkable without the use of pesticides (herbicides, insecticides and fungicides). On the other hand, these chemicals contribute to the pollution of the atmosphere, surface and underground waters, and agricultural soils, especially if they are applied improperly.
    The sustainable agricultural production pays attention to environment-friendly cultivation-technologies; but at the same time it makes an effort to produce good quality and economical products. The examination of the herbicides’ secondary effects, fits into this chain of idas namely, how the herbicides affect – stimulating or inhibiting – the soil microbiological processes, prevention of soil fertility.
    In the course of the experimental work the effect of herbicides on soil biological properties were examined in different maize (Zea mays) cultures. We wanted wished to know that how the herbicides affect the quantity change of soil microorganisms, the life of different physiological groups of bacteria and the activity of microorganisms. A small pot experiment was set up in 2008 with the application of two herbicides - Acenit A 880 EC and Merlin 480 SC – in the breeding house of the Department. The moisture content and nutrient supply were at optimal level in the experiment.
    On the basis of results the following can be stated: 
    1. It can be stated that the two herbicides and all their doses affected negatively the number of total soil bacteria, the
    inhibiting effects were significant. The quantity of microscopical fungi increased by the effect of Merlin 480 SC and decreased in the treatments of Acenit A 880 EC.
    2. The Acenit A 880 EC had stimulating effect on the nitrate mobilization. The CO2-production was stimulated by the basic doses of herbicides; the other treatments did not influence the CO2-production significantly.
    3. The quantity of microbial biomass-carbon –except for only one treatment- decreased significantly by the effect of herbicides. Besides it, the quantity of microbial biomass-nitrogen increased significantly in the treatments of Acenit A 880 EC.
    4. The biomass of test plant decreased in the treatments of herbicides, their quantities were smaller than in the control. In the pots treated by Merlin 480 SC, parallel with the increase of doses decreased the quantity of plant-biomass.

  • The effect of NPK fertilization and the number of plants on the yield of maize hybrids with different genetic base in half-industrial experiment
    103-108
    Views:
    221

    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.

  • The effect of grazing of various cattle breeds on botanical composition of low-lying pasture in Hortobágy
    57-63
    Views:
    288

    Coenological surveys were conducted in the Hortobágy National Park (Pap-ere and Zám-puszta) in May 2015 and 2016. During the tests,a total of 40 permanent plots were analyzed on grasslands grazed by extensive cattle (Hungarian Grey) and mixed genotype intensive cattle. The presence of plant species, percentages of total coverage of species and vegetation cover were recorded. Two habitat types were chosen according to their moisture content: wet salt marsh meadow (Bolboschoenetum maritimi) and drier salt meadows (Beckmannion eruciformis).

    We compared the impact of increased number of animals (2016 years) and the low number of animals (2015 years, initial state) and the grazing exclusion on vegetations.
    We tested: (i) what is the impact of grazing on the vegetation, (ii) how do species composition and vegetation charachteristics differ in the two habitat types (iii) and is there a difference in the impact of different cattle breeds (Hungarian gray, intensive beef cattle) grazing on the grasslands species composition? During the investigation we found, (i) that the greatest number of species was recorded in 2015, on the area that received moderate to intensive grazing (14.3 species per m2). Somewhat the number of species was reduced in 2016 due to more intensive grazing. The control group had the lowest number of species (11.7 species per m2). The undergrass and legumes cover significantly increased on intensive grazed lands. (ii) Our results indicate that the effects of different grazing differ in the two studied habitat types. On the drier grasslands greater number of species were found (16.2 species per m2), oppositely to the wet grassland (11.2 species per m2). The cover of the undergrasses was higher in the drier habitat than in the wet. (iii) The extensive beef cattle left a bigger number of species (16 species per m2) than the intensive beef cattle (11.4 species per m2). The grass cover was more intense on areas grazed by intensive cattle. The absolute and potential weeds cover showed a higher value on areas grazed by Hungarian Grey. Our two-year results suggest that grazing by both extensive and intensive cattle breeds can be a proper tool for the conservation management of alkali grasslands.

  • Effect of tillage practices, fertilizer treatments and crop rotation on yield of maize (Zea mays L.) hybrids
    43-48
    Views:
    207

    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.

  • Yield of herbicide tolerant sunflower hybrids due to the different herbicide treatments
    121-125
    Views:
    133

    Sunflower is our most important oil-plant grown on the largest area in Hungary. In Europe sunflower has been grown since the 16th century. In recent years sunflower growing area is between 450-500 thousand hectares. Weed management in sunflower production is getting more and more difficult in case of annual and perennial dicotyledonous weeds, especially in dry springs. Two active ingredients, imazamox and tribenuron-methyl could be a solution for farmers for the control of these weeds in herbicide tolerant sunflower hybrids (Christensen-Reisinger 2000, Hódi-Torma 2004, Nagy et al. 2006). Most of the farmers choose the Clearfield technology and the use of tribenuron-methyl herbicides. In 2009 imazamox- (IMI) and tribenuron-methyl- (SU) tolerant sunflower hybrids were produced on 200 hectares in Hungary, of which 150 hectares was IMI, while 50 hectares was SU-hybrids. Small plot experiments were carried out to investigate the phytotoxicity of herbicides on imazamox (IMI) and tribenuron-methyl (SU) tolerant sunflower hybrids under field conditions. At harvest we measured the moisture content of achenes and average yield.