János György Nagy

Dr. János György Nagy

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 December 2015 in Journal of Maps
Verified
Journal Article
Open access
MTMárton Tolnai
Márton Tolnai
JNJános György Nagy
János György Nagy
GBGábor Bakó
Gábor Bakó
Landsat imagery is the most frequently used remotely sensed data in many fields related to the monitoring of the Earth's surface. As Landsat satellites have gathered data since 1972, lots of valuable information has been stored and can be derived from imagery over a long time interval. Of course, due to certain factors such as weather conditions and satellite-related technical issues, data collection cannot be consistent in time and space. Cloud coverage is the most obvious condition that determines the usability of a remotely sensed satellite images. For successful results, a rich data supply is essential. To explore the data supply of a certain study area, the Landsat metadata can be checked which is usually an involved process especially for a long time interval. Therefore, the visualisation of Landsat metadata can result in a faster work flow and successful study area selection. In this paper we present a cloud cover-weighted metadata map for the area of Europe.

25 April 2025 in Agronomy
Verified
Journal Article
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ETErzsébet Tóth
Erzsébet Tóth
ZDZita Dorner
Zita Dorner
JNJános György Nagy
János György Nagy
MZMihály Zalai
Mihály Zalai
This study explores the relationship between abiotic factors, farming practices, and weed growth in winter wheat fields in Eastern Hungary. It examines the order of weed dominance and the influence of soil, environmental, and agricultural variables on weed composition and diversity before herbicide application. The research was conducted across four sub-regions in the Great Hungarian Plain, each with distinct soil, hydrological, and geographical conditions. Between 2018 and 2021, 103 fields were surveyed and weed species cover was recorded using EPPO-based identification and quadrat sampling. Soil properties, environmental conditions, and farming practices were documented through soil analysis, geographical data, and farmer interviews. Statistical analyses were preformed including ANCOVA, redundancy analysis, and Shannon diversity index calculations. The results show that common weed species include Veronica hederifolia, Stellaria media, and Apera spica-venti, with winter annuals dominating. Soil compaction and salinity affected weed diversity, while increased copper and zinc concentrations had minor effects on weed coverage. Farming practices, particularly tillage systems and fertilizer use, had a significant effect on species richness and diversity. Different regional and annual weed distributions were observed, with correlation between certain tillage systems and specific weed species. The results emphasize the need for climate-conscious farming practices, and we recommend prioritising shallow cultivation and deep loosening over ploughing in order to manage weed populations effectively. These insights contribute to sustainable weed management strategies in cereal production.

7 December 2023 in Nature Conservation
Verified
Journal Article
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AHAnett Hanny-Endrédi
Anett Hanny-Endrédi
ÁSÁrmin Sőth
Ármin Sőth
DÉDóra Ércz
Dóra Ércz
DBDeák Balázs
Deák Balázs
Orsolya ValkóOrsolya Valkó
Orsolya Valkó
JNJános György Nagy
János György Nagy
We aimed to investigate the reproduction-related traits of Vicia biennis L., an endangered and poorly known wetland species in its western marginal populations (in Hungary), and discuss the conservational and ecological implications. We measured the mass, viability, and physical dormancy of half-year-old seeds in five in-situ collected seed lots, while potential seed longevity (i.e., seed bank type) was estimated from repeatedly germinating subsamples from four ex-situ collected seed lots for 3–8 years. Plant survival, flowering, and seed production were studied in different light-, irrigation-, and competition conditions in a botanical garden experiment. We found that 1) half-year-old seeds have a high germination capacity (78–100%), 2) and high level of physical dormancy (72–100%) in all examined Hungarian populations, and 3) the seeds can preserve their germination capacity for more than five years, although their viability sharply decreases, probably falling below 10% within ten years, when they are stored at room temperature. The results of the botanical garden experiment suggested that 1) the species is annual, not biennial; 2) it shows strong sensitivity to precipitation and low competitiveness for water; and 3) it can produce hundreds of seeds even in suboptimal (dry or shady) conditions. Although the species was found to be well-adapted to a temporally heterogeneous environment, its future vulnerability can increase depending on the duration of dry seasons. Further investigation of genetic diversity and soil seed bank is needed to estimate the actual vulnerability of the species while strengthening the populations through seed sowing, and additional vegetation control in the habitats is suggested.

26 July 2025 in Agronomy
Verified
Journal Article
Open access
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MZMihály Zalai
Mihály Zalai
ETErzsébet Tóth
Erzsébet Tóth
JNJános György Nagy
János György Nagy
ZDZita Dorner
Zita Dorner
The primary aim of this study was to explore the influence of abiotic factors on weed development in maize fields, with the goal of informing more effective weed management practices. We focused on identifying key environmental, edaphic, and agricultural variables that contribute to weed infestations, particularly before the application of spring herbicide treatments. Field investigations were conducted from 2018 to 2021 across selected maize-growing regions in Hungary. Over the four-year period, a total of 51 weed species were recorded, with Echinochloa crus-galli, Chenopodium album, Portulaca oleracea, and Hibiscus trionum emerging as the most prevalent taxa. Collectively, these four species accounted for more than half (52%) of the total weed cover. Altogether, the 20 most dominant species contributed 95% of the overall weed coverage. The analysis revealed that weed cover, species richness, and weed diversity were significantly affected by soil properties, nutrient levels, geographic location, and tillage systems. The results confirm that the composition of weed species was influenced by several environmental and management-related factors, including soil parameters, geographical location, annual precipitation, tillage method, and fertilizer application. Environmental factors collectively explained a slightly higher proportion of the variance (13.37%) than farming factors (12.66%) at a 90% significance level. Seasonal dynamics and crop rotation history also played a notable role in species distribution. Nutrient inputs, particularly nitrogen, phosphorus, and potassium, influenced both species diversity and floristic composition. Deep tillage practices favored the proliferation of perennial species, whereas shallow cultivation tended to promote annual weeds. Overall, the composition of weed vegetation proved to be a valuable indicator of site-specific soil conditions and agricultural practices. These findings underscore the need to tailor weed management strategies to local environmental and soil contexts for sustainable crop production.

17 March 2026 in Heritage
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MMMelinda Nagyné Molnár
Melinda Nagyné Molnár
ENEnikő Nemes
Enikő Nemes
TCTimea Csizmadia
Timea Csizmadia
JNJános György Nagy
János György Nagy
Romania joined the UNESCO Convention in 1990. The fortified church of Biertan was inscribed on the World Heritage List in 1993, followed by six additional Transylvanian fortified church villages in 1999. An interesting feature of this heritage landscape is that settlements with different demographic and development trajectories share the same World Heritage designation. In our research, we collected demographic and tourism data from these seven municipalities. Subsequently, a standard questionnaire was sent to municipal decision-makers (mayors) in 2023 to map tourism development in their municipalities. The communication activities of the municipalities were analysed using a content analysis method, which was observation-based and based only on online content. In our experience, there is no common strategy to turn this heritage into a tourist attraction; each of the seven municipalities has faced this challenge separately. The main result of the research was to explore how heritage tourism works in municipalities with different demographic, linguistic-cultural heritage and with different levels of management.

26 February 2026 in Plants
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Journal Article
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JNJános György Nagy
János György Nagy
AMAnna Morzsányi
Anna Morzsányi
AMAdrián Molnár
Adrián Molnár
ISIstván Somogyi
István Somogyi
MMMelinda Molnár
Melinda Molnár
LGLilla Diána Gilián
Lilla Diána Gilián
Orchid pollination is traditionally considered to rely on intact pollinarium transfer by animal vectors. Species lacking a functional viscidium are generally classified as obligately autogamous. In this study, we investigated the reproductive biology of Epipactis bugacensis, a taxon long regarded as strictly self-pollinating. Floral visitor activity was assessed through repeated field observations, and pollinator dependence was tested using a pollinator-exclusion (net-covering) experiment at two Hungarian populations, combined with measurements of fruit set, capsule volume, seed number, and seed density. We documented a previously unreported pollen-transfer mechanism in E. bugacensis, whereby halictid bees fragment pollinia and transfer these fragments in their scopa to neighboring flowers enabling geitonogamous deposition and suggesting the potential for xenogamous pollen transfer. Other visitor taxa showed no evidence of effective pollen transport. Mesh coverage increased fruit set, capsule volume, and seed number, while seed density remained unchanged. Reproductive output declined from basal to apical positions along flowering shoots, revealing strong internal resource-allocation constraints. Overall, E. bugacensis is predominantly self-pollinating but not strictly obligate autogamous, and its reproductive success is governed primarily by microhabitat quality rather than pollinator availability.