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Possibilities of use of selected entomopathogenic fungi in biological control of agricultural pest species
KONOPICKÁ, Jana
Ph.D. thesis is focused on the entomopathogenic fungi that can be used in biological control. Ph.D. thesis consists of two main parts: 1) a detailed background research, and 2) five subchapters of the experimental part and results, which contain original publications describing results of my own studies. The first study focused on the isolation and identification of new strains of entomopathogenic fungi from soil samples collected in garlic and onion fields in the Czech Republic and Israel. Furthermore, the efficacy of selected fungal strains against the bulb mite Rhizoglyphus robini was tested. A total of 5 genera of entomopathogenic fungi (Metarhizium sp., Beauveria sp., Isaria sp., Lecanicilium sp. and Purpureocillium sp.) were identified among the soil isolates from both countries. The most frequent was the genus Metarhizium sp. especially in sampling sites of the Czech Republic. The highest efficacy against Rhizoglyphus robini mites was found in Metarhizium anisopliae strains isolated from soil samples collected in the Czech Republic and in Metarhizium indigoticum strain from Israel. Mortality after 4 days of the bioassay was almost 100%. The second study investigated the efficacy of the entomopathogenic fungus Isaria fumosorosea CCM 8367 against box tree moth (Cydalima perspectalis). Fungal infection was mostly observed in pupae. However, mortality did not exceed 60%, indicating a very low susceptibility of box tree moth to Isaria fumosorosea CCM 8367. In the third subchapter, various strains of entomopathogenic fungus Beauveria bassiana were tested against the Colorado potato beetle, a serious pest of potato. First, laboratory experiments were performed and the most virulent strain BBA 08 against this pest was selected and used subsequently in further experiments. The strain efficacy against L. decemlineata adults was evaluated in pot experiments and under field conditions. The fungus was applied alone and in combination with entomopathogenic nematodes. In all experiments, the fungus reduced the number of Colorado potato beetle adults by about 30% compared to the control. The fourth study described enrichment of soil substrate with entomopathogenic fungus Isaria fumosorosea CCM 8367 for increasing its suppressivity. The results showed that the fungus successfully colonized the soil substrate and remained in it for more than 6 months at 20 °C, although the average concentration decreased slightly from 5.89×104 to 2.76×104 spores per milliliter of substrate during the experiment. The last study described dissemination of Isaria fumosorosea CCM 8367 spores by nematodes of Steinernema feltiae and Heterorhabditis bacteriophora. The results of our study revealed for the first time that the spread of conidia and blastospores of Isaria fumosorosea in soil environment is significantly enhanced by the presence of entomopathogenic nematodes.
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Možnosti využití online senzorových systémů pro variabilní aplikaci dusíkatých hnojiv
Škrabal, Jakub
This bachelor thesis describes the possibility of using spectral measurement of nitrogen fertilizers in variable application especially on winter wheat. The theoretical part describes the fashion and the principle of spectral measurement and the essence of nitrogen in field´s crop nutrition. This part also lists sensors available in the market. In a practical part of the thesis there is a description of operational experiment in which the Isaria sensor from Fritzmeier company was tested. This sensor has been tested for two years on winter wheat. In a argumentative part of the thesis there is a comparison of the results from this two experimental years and the evaluation of each variant of the sensors setting. The focus was specially on the following indicators: quantity of applied nitrogen, the utilisation´s efficiency of nitrogen on production unit and the content of nitrogen´s substance in grain and yield. Moreover there are mentioned the economic effects of the difference in uniform and variable dosage of the nitrogen fertilizers.
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Vyhodnocení variabilní aplikace hnojiv senzorovým systémem Isaria
Škrabal, Jakub
This diploma thesis concerns the evaluation of a four-year sensor testing of the Fritzmeier ISARIA system. In a literature review is described nitrogen variable fertili-sation, the diagnostics of nutritious plant condition. The sensor system ISARIA is also described including vegetative index and individual modes settings. In a practical part is described four years testing of the Fritzmeier ISARIA system in a company Salix Morava a. s. in Zdounky region. In results there are listed parameters like yield, the quantity of applicated nitrogen, the effectivity of nitrogen application the quality of production and revenues. The results shows significant economic and environmental effects resulting from variable nitrogen application. The results are also statistically evaluated for enabling to be a part of a conclusion. It can be seen form the results, that a significant, impact for an economic contribution of a variable nitrogen application is affected by a field, year, cultivar, but also by settings of a sensor system.
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