Szerző szerinti böngészés "Veres, Edina"

Megjelenítve 1 - 3 (Összesen 3)
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    Gyepek talajának és rizoplánjának összehasonlítása
    (2021-12-31) Kátai, János; Veres, Edina
     The aims of this paper were to determine and compare the most important physical, chemical and microbial characteristics of seven grassland areas near Debrecen.      Physical properties: moisture content (t%), clay and silt contents (Li%), soil plasticity according to Arany (K A ), were measured.   As were the chemical characteristics: pH, salt content (%). lime content (it depends on pH), humus content, organic nitrogen and mineral materials (nitrate nitrogen, ammonium lactate soluble phosphorous and potassium).      The total viable number of bacteria, the amount of cellulose decomposing and nitrifying bacteria and the quantity of microscopic fungi were studied. Additionally, some soil enzyme activities, such as phosphatase and catalase as well as carbon-dioxide production were determined.      The number of microbes and the microbiological activity of the soils were higher in autumn than in summer. The lowest number of bacteria was determined in solonchak-solonetz soil. The phosphatase enzyme activity and the CO 2 production are connected with the higher organic matter content of the soils. The increasing sodification decreased the phosphatase activity and the intensity of CO 2 production. Meadow soil type led to an increase in catalase activity. During the examination zhe rhizoplane of two test plants per grassland was also studied. The umber of microorganisms in the rhizoplane of test plants was usually higher than the values obtained in soil samples.      Within one soil types there were differences between two test plants including the same or different family.      There were no considerable differences among the number of fungi genera isolated from the soil samples and the rhizoplane or among the results obtained in summer and autumn. Independent of the soil types and plant species, Fusarium, Mucor and Penicillium genera were found in large percentages promoted by the rainy summer and autumn season. 
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    A tárolási feltételek hatása a kukorica Fusarium fertőzöttségére és toxin szennyezettségére
    (2002-03-27) Veres, Edina; Borbély, Mária; Győri, Zoltán; Kátai, János
    Corn samples harvested in 1997, 1998 and 1999 from different soil types were stored at different conditions (temperature, moisture content, state of kernels) for six months. The Fusarium contamination was examined by plate dilution method and the amount of mycotoxins (F-2, T-2, HT-2, DON, DAS) were determined applying HPLC method immediately after harvesting and in the third and sixth month of storage. The aim of our study was to find correlation between the ecological factors, storage conditions and the examined parameters mentioned above, as well as to prove them statistically. According to the examinations carried out after harvesting we could state that the soil type had no effect on the parameters. Analysing the effect of the years we found considerable differences. The Fusarium infection of corn samples in 1998, while the toxin contamination in 1999 was the highest. The results of storage experiment show that year (number of microscopic fungi, F-2, T-2, HT-2, DAS and total toxin content) and moisture content of kernels (F-2, T-2, and total toxin content) have a significant effect on the examined parameters. We could prove the effect of temperature on the T-2 content (samples with natural moisture content) and DON content (samples with 14% moisture content). Higher values were found at higher temperature storage. The ratio of damaged kernels influenced the DON concentration in the non- wetted samples and the number of microscopic fungi in the wetted samples.
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    Utility of Winter Wheat According to Visual and Microbiological Fusarium Infection, as Well as Toxin Examination
    (2003-11-26) Veres, Edina; Borbély, Mária
    In 1998 the Fusarium infection was studied visually and microbiologically and also F-2, T-2, HT-2, DAS and DON contamination were measured using 22 winter wheat samples. The correlation between the different parameters of 22 wheat samples were determined by regression analysis. According to our results we can state the following. There is no significant connection between the results of visual, microbiological and toxicological examinations. This means that no certain conclusion can be drawn about the toxin contamination of samples – which is a determining factor of its utility – based on the visual symptoms and the plate dilution method. Our results indicate however – though it is not proven statistically – that those samples in which the Fusarium infection did not exceed the limit of the standard, also had low toxin contamination, therefore they can be used as components of forage. It is a considerable problem, however, that according to the visual qualification, such samples are excluded from the later utilisation, wherein the toxin contamination does not justify such action. Therefore, it is necessary to examine the toxin content of those samples which show high infection by visual symptoms. To reducing the number of expensive toxin examinations it would be advisable to change the currently used 0,5% limit which is indicated in the standard for a higher value of infection, for example to 2%, as recommended by Mesterházy (1998).