Szerző szerinti böngészés "Nagy, A."
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Tétel Szabadon hozzáférhető A Debreceni Szembank(1995) Módis, László; Szalka, A.; Berta, András; Takács, Lili; Balázs, Krisztina; Nagy, A.Tétel Szabadon hozzáférhető Applicability of 3D laser scanning in precision horticulture(2011-12-04) Tamás, J.; Riczu, P.; Nagy, G.; Nagy, A.; Jancsó, T.; Nyéki, J.; Szabó, Z.Due to the technological development, remote sensing instruments and methods have become widespread in all segments of life (from precision agriculture through architecture to medicine). Among the innovative development of remote sensing instruments the 3D laser scanner is of outstanding importance. Horticultural applicability of terrestrial laser scanning technique is a new innovation in the precision agriculture. The structure of trees and branches, the canopy extension, the fruit yield, which can help to recognize some biophysical parameters, can be determined. The examination was carried out with Leica ScanStation C10 terrestrial laser scanner in the Study and Regional Research Farm of the University of Debrecen near Pallag. In this article the measuring principle, the parameters and horticulture applicability of the terrestrial laser scanner are presented.Tétel Szabadon hozzáférhető Applied spatial analytic tools in orchards with special regard to agro-ecology(2011-03-15) Fórián, T.; Nagy, A.; Tamás, J.; Szabó, Z.; Soltész, M.; Nyéki, J.Our investigation was carried out in several orchards in Hungary. This study reviews applicability of the different spatial analytical techniques in orchard especially models based on surface relief, such as digital elevation model, digital terrain model, slope and aspect maps. In recent time, the generation of digital elevation model has become a popular examination method. However, the elevation models generated from contour lines or elevation points could be applied to evaluate agro- ecological potential of fruit orchards to some extent. The highest deficiency of these models is the fact that these show the altitude of soil surface only and do not demonstrate landmarks on the surface. Consequently, the calculation of the radiation value results data relating to soil surface. The terrain model generated and applied by our team demonstrates fine surface texture and the landmarks in the orchard, so it is suitable for further examination.Tétel Szabadon hozzáférhető Assessment of soil characteristics in orchard(2012-04-25) Nagy, A.; Fórián, T.; Tamás, J.; Szabó, Z.; Nyéki, J.; Soltész, M.The research field was at Siófok, in Hungary, which is situated in the South East side of Lake Balaton. The physical characteristic of the soil is sandy loam and loam and the peach orchard is irrigated. The detailed goals were mapping and analyzing of physical properties of the soil in water management point of view, mapping the acidity and CaCO3content of soil for precision liming, measurement of humus the element content. Sites with different physical characteristics (from sandy loam to loamy clay) could be distinguished. The reason for this is that besides the possible increase of clayminerals, the increasing rate of colloidal humus content contributes to larger soil plasticity. Statistics also proved positive and strong correlation (r=0.822) between the soil plasticity and humus content. In the case of pH, only a small part of the orchard is has to be limed, since most of the orchard has neutral pH, which is advantageous for nuts and stone fruits. It has to be mentioned, that the CaCO3 supply is also appropriate for the stone fruits. Based on the results hyperspectral imagery can be a good solution for detecting calciferous soils, although these measurements are still need validation.Tétel Szabadon hozzáférhető Colour and water content detection of sweet cherry by portable spectrometer(2011-12-04) Nagy, A.; Tamás, J.; Soltész, M.; Nyéki, J.; Szabó, Z.Based on the most recent data, the average amount of sweet cherry produced in Hungary is around 10-12 thousand tons. Therefore fast and effective method is important for sweet cherry fruit quality analyses. The aim of the study was to examine the applicability of reflectance measurements for sweet cherry fruit quality analyses. In our experiment five cherry species (Vera, Cristalina, Germersdorfi, Noir de Mechet, Canada Giant) were examined in order to measure the spectral differences between species. Further more, spectral alteration was examined between different health and maturity status of the fruits in the case of a specified, the Germesdorfi species. The four new indices are appropriate tools for cherry quality analysis. Thus reflectance measurements can also support more precise and automated fruit selections. The methods for the differentiation of species could also be viable at a concerned habitat; however, the climate, habitat and soil conditions strongly affect the yield quality. Concerning the fast determination of water content, WBI could be a reliable method for the assessmentTétel Szabadon hozzáférhető Determination of chlorophyll content in case of peach leaf curl disease (Taphrina deformans) with spectral analysis(2016-07-02) Riczu, P.; Bíró, Gy.; Sulyok, E.; Nagy, A.; Tamás, J.; Szabó, Z.One of the most important conditions of high quality fruit production is the early detection of hytopathologycal infections. The most dangerous disease of peach (Prunus persica) is the Taphrina deformans, which causes serious damages mainly in the years where the weather condition is cool and wet. In this study, healthy and naturally diseased leaves by peach leaf curl were investigated in the laboratory of University of Debrecen, CAAES, Institute of Water and Environmental Management. Both of hyperspectral measurement and the values of spectrophotometer shown the chlorophyll content of diseased leaves were lower than the healthy samples. Based on the experiments the water status of investigated leaves established the infected leaves contained more water in their tissues.Tétel Szabadon hozzáférhető Drought stress monitoring by laboratory and satellite spectral methods in an apple orchard(2014-04-22) Nagy, A.; Riczu, P.; Tamás, J.An orchard can be examined on the basis of spectral data, using such methods with which the reflected radiation can be divided into a large number of (several hundreds) small spectral channel (some nm). Based on the spectral characteristics of the canopy, or the different index numbers calculated from hyperspectral data the water supply conditions of foliage can be well characterized. The research site is an intensive apple orchard, which located in Debrecen University, Centre for Agricultural and Applied Economic Sciences, Farm and Regional Research Institute at Pallag. During our experiments the evaluation of spectral, non-invasive measurement method are carried out for detecting stress symptoms caused by drought. Furthermore, MODIS NDVI time series data were analyzed for orchards situated in North-Eastern part of Hungary in drought effected and wet years in order to detect differences. Significant differences in NDVI values were detected after the end of June.Tétel Szabadon hozzáférhető The effect of storage to optical properties in case of two apple fruit varieties(2016-07-02) El Shal, A. M.; Riczu, P.; Nagy, A.; Sulyok, E.; Szabó, Z.; Nyéki, J.The keeping quality of fruits is a very important factor in storage point of view, since it could be elongated the consumption time of fruits. In many cases the storage may be necessary, e.g. in short time it is not able to market due to the rich harvest, or all fruits could sell in markets throughout the year. The keeping quality of various fruit species is greatly different; moreover it could be observed some differences between the varieties as well. In our research, we have investigated the spectral properties of the external surface and fl esh of two ripe apple varieties – Jonagored and Granny Smith – before and after storage (about 3°C and about three weeks). The hyperspectral investigation was carried out with AvaSpec-2048 Fiber Optic Spectrometer. The experimental results represented the differences between healthy and chilling injured apple fruits. Furthermore, some indices were created to given countenance to the spectral differences.Tétel Szabadon hozzáférhető Evaluation of fruit tree transpiration with heat flux sensor(2014-04-22) Riczu, P.; Nagy, A.; Tamás, J.One of the biggest professional challenges of the following years is to develop the water resource management for apple trees. In order to know the water consumption of plants, some traditional and modern methods could useful. In our research the sap flow measurement of the plants were carried out. We have analyzed the transpiration properties of the trees in the investigation period. In order to compare the transpiration of the trees, the leaf areas were scanned and evaluated. Beside these measurements, soil water properties were determined by tensiometers, thus it makes possible to observe the soil-plant-atmosphere system.Tétel Szabadon hozzáférhető Evaluation of fruit tree waterstress condition and transpiration with heat fl ux sensors(2016-07-02) Nagy, A.; Riczu, P.; Tamás, J.; Szabó, Z.; Soltész, M.; Nyéki, J.In this study the transpiration properties and response to heat stress of Granny Smith and Jonagold apple species were measured. The examinations were set at an orchard near to Debrecen. The chosen trees were two years old, without fruits, in 20l container, placed in the mixture of mulch matrix, wood chips and sawdust and grown at the same climatic conditions. One of the most important goals was to determine the leaf area of the trees which is a basic data for transpiration modeling. Leaf area was larger (signifi cance level p<0.05) in the upper part of the canopy to achieve larger photosynthetic surface. Jonagold species with less leaf number (–18% compared to Granny Smith) reached almost the same canopy area, than Granny Smith, due to larger leaf area of Jonagold. Another aim was to measure the transpiration rate of the apple trees. The transpiration measurements were carried out by sap fl ow meter. Only a small transpiration difference can be found between species. During the investigation time there were wet and cool as well as dry and extremely hot periods. In the case of dry and extreme hot periods the transpiration is decreased, which causes decrease in transpiration and enhanced the water stress of trees.Tétel Szabadon hozzáférhető Hyperspectral data in water stress detection(2014-09-07) Riczu, P.; Nagy, A.; Tamás, J.Remote sensing methods are applied widespread to investigate large land fields. Within these methods the status of certain vegetation can be determined based on the reflectance spectra of the chlorophyll, in order to support agriculture, forestry and the evaluation of soil pollution. The main aims of our study were to determine and validate the reflectance spectra of fruit tree species, in order to facilitate the identification and evaluation of stressed fruit trees in orchards.Tétel Szabadon hozzáférhető Integration of terrestrial laser scanning and spectral canopy scanner in horticulture applications(2012-04-25) Tamás, J.; Riczu, P.; Nagy, A.; Nyéki, J.; Gonda, I.; Szabó, Z.One of the most difficult challenge in the everyday practice to describe the canopy growing of fruit trees in an orchard. The photosynthetic activity is the basic of the primer production of plants. The measurement of leaf area and determination of the photosynthetic activity could be occurred with some elaborated methods between experimental conditions. In this article we present such an integrated methodology, which is ideal to determine the geometric and spectral characteristic of fruit trees between field conditions.We have carried out laser scanning technology to investigate the geometric-topological characteristics and parallel the active infra-red sensor to collect spectral data about an apple orchard. The surveys were worked out in an intensive apple orchard with drip irrigation system, protected by hail net in Study and Regional Research Farm of the University of Debrecen near Pallag. This study shows the filtering and interpretation methods of created data. The produced high accuracy data can be directly used in the precision horticulture. It could serve as a guiding data to implementation a future “virtual horticulture”. Higher spatial and temporal resolution could help for a better recognition of water balance of orchards.Tétel Szabadon hozzáférhető Irrigation management of a peach orchard(2012-04-25) Nagy, A.; Riczu, P.; Tamás, J.; Szabó, Z.; Nyéki, J.; Soltész, M.The research field was at Siófok, in Hungary, which is situated in the South East side of Lake Balaton. The physical characteristic of the soil is sandy loam and loam and the peach orchard is irrigated. Mainly Sweet Lady (early ripening), Red Heaven (medium ripening) and Weinberger (early ripening) species were installed. In order to achieve the optimal developement level of trees and maximal yield amount and fruit diameter (Sweet Lady 60–75 mm, Red Heaven 60–70 mm, Veinberger 50–60 mm) continous water and nutrient supply is required. The irrigation modeling was set by CROPWAT 8.0 based on the climatic, crop and soil data inputs of the last 10 years. Based on the results, large amount of water is needed for optimal growth of fruit trees, particularly in the summer months, in case of active ground cover (+) and bare soil (–) as well. The irrigation requirement of a tree was found maximum 4 l/hour in certain cases. This irrigation intensity can be achieved – calculated with 12-hour operating time – by using continuous water NAAN Tif drip tube with 2 l/h flux on 3 atm pressure with 16 mm pipe diameter. If lower irrigation intensity is required irrigation can be controlled by the decreased the operation time.Tétel Szabadon hozzáférhető Irrigation modeling in a pear orchard(2010-05-10) Nagy, A.; J., Tamás; T., Fórián; J., Nyéki; M., Soltész; Z., SzabóThe pear has large water requirement, therefore the planting of high density and grass covered pear orchards are needed irrigation conditions in Hungary. Drip irrigation spread in the orchards is due to the 90–95% of water use efficiency. One of the key role of irrigation is the proper determination of evapotranspiration and crop coefficients. As there is a considerable lack of information for different crops or fruits the Penman-Monteith method is used for the estimation of evapotranspiration, using CROPWAT 8.0. The research field was the genetic collection of pear at Újfehértó, in Hungary, which is situated in Nyírség meso-region. Our aim was to establish drip irrigation at this site. Based on the results of CROPWAT irrigation model the mean amount of the total gross irrigation is between 230–270 mm, within 3 irrigation interval regarding climatic and rainfall data of the last 10 years. In 2009, due to heavy drought, the total gross irrigation was 355,4mm/year on sandy soil calculating with 45% total available water depletion in 5 irrigation interval. The sizing of the irrigation system was set to the maximum 0.55 l/s/ha, which is 6.3 l/tree/h. 6.3 l/tree/h can be carried out with a drip emitter having 16 mm wing lines diameter, 4 l/h water flow at 3 atm pressure.Tétel Szabadon hozzáférhető Monitoring of water regime in an apple orchard(2011-03-15) Nagy, A.; Fórián, T.; Tamás, J.; Nyéki, J.; Szabó, Z.; Soltész, M.Our investigation was carried out at an micro-irrigated intensive apple orchard in Debrecen-Pallag in 2010. The aims of the study were to monitor the effect of a compacted layer on soil water regime by tensiometers and supporting the water management of the orchard. The results suggest that the physical characteristic of the examined soil is sandy soil with low capillarity and total available water content. The soil water tensions were varied between pF 0 and 2.5 due to the extreme precipitation circumstances in 2010. Tensiometers in 40 cm depth resulted fast (few hours) and significant respond to precipitation than in the 70 cm soil layer. Based on daily measurements, the soils possess a daily fluctuation of soil moisture, however the changes become more moderate in deeper layers. In accordance with all of the results, the amount of drainable water regime was about 20.6 V/V% at 40 cm depth and 18.6 V/V% at 70 cm mainly. The harmful surplus water can be infiltrated by loosening of the compacted soil layer in 50–70 cm depth or led off by vertical drainage.Tétel Szabadon hozzáférhető Pilot study for irrigation modelling of a pear plantation(2010-05-10) Tamás, J.; Fórián, T.; Nagy, A.; Nyéki, J.; Soltész, M.; Szabó, Z.Our investigation was carried out in the area of Fruit growing Research and Consultant non-profit company, at Újfehértó. The pear requires large water quantity, but this pear plantation hasn’t irrigation system not yet. This study reviews the drainage conditions of the area based on digital elevation model, and examined the canopy cover of pear trees by evaluating of the hyperspectral image. Our aims were to determine the exact watershed based irrigation modelling and determining of the canopy% of the pear orchard to facilitate a precision irrigation decision support system.Tétel Szabadon hozzáférhető Precision geoinformatical system of the pear gene-collection orchard(2012-04-25) Tamás, J.; Nagy, A.; Fórián, T.; Nyéki, J.; Szabó, T.; Szabó, Z.The principle task of the sustainable development is the preservation of the genetic variety, which is similar challenge in the horticulture regarding the sublimation of fruit species. The breeders of the traditional fruit strains give stock to the sustenance diversity of the agro-environment on the species and landscape level. In 2009, hyperspectral images have been taken by AISA Dual sensors from the pear gene pool in Újfehértó, Hungary. The hyperspectral data cube (in the wavelength range of 400-2500 nm, with 1.5 m ground resolution) ensured possibility to make the spectral library of pear species. In the course of the simultaneously field work the spatial position and individual extent of all pear trees was defined to set up a detailed GIS data base. The water stress sensitivity of single species and the descriptive spectral curves were determined with common evaluation of the spectral and spatial data. Based on the unique methodology processing and the hyperspectral data base suitable strains can be chosen for agro-environment and let take adaptive stocks regarding climate change into the genetic grafting work. Furthermore we could determine and map the sparsely species in the region with the help of the hyperspectral data.Tétel Szabadon hozzáférhető Preliminary data on attractiveness of phenylacetaldehyde-based lures on economically important plant bug pests (Hemiptera: Miridae)(2021-07-21) Szalárdi, T.; Nagy, A.; Oláh, F.; Tóth, M.; Koczor, S.Several plant bug species (Miridae) are important pests of crops and vegetables, thus monitoring them is of essential importance for effective pest control. During the current, preliminary study synthetic plant volatile combinations were tested in field conditions in Hungary in alfalfa fields. Beside semiochemical baited traps, sweep-netting was also performed. In the experiments three plant bug species were found in higher numbers: Adelphocoris lineolatus , Lygus rugulipennis and L. pratensis . As a novel, interesting finding L. pratensis was attracted to phenylacetaldehyde baited traps. For all species, both males and females were trapped in all combinations. Sweep-netting and semiochemical baited traps showed different efficacy in case of the three species, as sweep-netting catches were highly biased for A. lineolatus , which indicates the higher efficacy of this method as compared to the tested semiochemical-baited traps. On the other hand, semiochemical baited showed better performance for L. rugulipennis and L. pratensis . For these species none of the tested combinations performed better than phenylacetaldehyde baited traps. The potential implication of results in view of monitoring are discussed.Tétel Szabadon hozzáférhető Vineyards characteristic by using GIS and refl ectance measurements on the Nagy-Eged hill in Hungary(2016-07-02) Fórián, T.; Nagy, A.; Riczu, P.; Mézes, L.; Tamás, J.Our investigation was carried out in vineyards on Nagy-Eged hill in Hungary. Grapevine growing plays an important role in Eger Vine Regions. In the grapevine cultivation it becomes necessary to know the requirements of vineyards along the best geographical situation using available cultivation and examination technology to achieve better and quality produce. This study reviews applicability of the different spatial analyst techniques in vineyard especially models based on surface relief and the new technology of hyperspectral analysis. The spectral alteration was examined between different health status and leaves infected by Eriophyes vitis to defi ne spectral characteristics. Thus reflectance measurements could also support to evaluate airborne hyperspectral images with the help of the spectral library.