National Repository of Grey Literature 43 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Influence of different tillage technology on the occurrence of weed species in cereals
JANUROVÁ, Eliška
The bachelor's thesis deals with the action of herbicides in terms of weed control in winter wheat. This is especially the occurrence of annual dicotyledonous weeds, herbaceous and perennial weed species. Of the selected herbicides, the best efficacy was found for the herbicide Mustang Forte in the conventional farming system and lower efficacy for Biathlon 4D when evaluated in a minimized mode of farming. The greatest herbicidal effect was recorded by Biathlon 4D against chamomile weeds.
Vliv metazachloru a jeho metabolitu metazachloru OA na raná vývojová stádia raka mramorovaného
ZÁVORKA, Milan
Metazachlor is a selective herbicide used for controlling monocotyledonous and dicotyledonous weeds in oilseed rape and other cruciferous plants. It is mainly used as a pre-emergence herbicide. Metazachlor OA is one of the major degradation products of metazachlor. The aim of this study was to evaluate the effect of metazachlor and its major metabolite metazachlor OA on the early live stages of marbled crayfish (Procambarus virginalis). The effect of metazachlor and metazachlor OA was evaluated on the basis of behaviour, growth, biomarker of oxidative stress, antioxidant biomarkers, ontogenetic development and occurrence of morphological anomalies. The toxicity test was performed at five concentrations, two concentrations of metazachlor (3.2 micrograms/l and 22 micrograms/l) and two concentrations of metazachlor OA (3.2 micrograms/l and 22 micrograms/l) and one control (C). The test exposure was 40 days under defined laboratory conditions. The exposure of metazachlor and metazachlor OA at all tested concentrations caused statistically significantly higher mortality, delayed ontogenetic development and slower growth of crayfish. Metazachlor exposure in concentration 22 micrograms/l and metazachlor OA in concentrations 3.2 micrograms/l and 22 micrograms/l caused statistically significant reduction of antioxidant enzymes (SOD, CAT, GR, GST and GSH) levels in whole-body crayfish homogenate. Metazachlor OA showed a more pronounced adverse effect on the early live stages of marbled crayfish than its parent compound, metazachlor. Based on the results of this study we can point out the suitability of crayfish, especially their early live stages for toxicity tests and the possibilities of their use for biomonitoring of aquatic environment herbicides and their metabolites.
Ecotoxicity of herbicidal ionic liquids
Müllerová, Tereza ; Cajthaml, Tomáš (advisor) ; Klusoň, Petr (referee)
Herbicidal ionic liquids (HILs) are organic salts with herbicidal properties. Their anions are usually derived from traditional herbicides, and they are paired with cations of a synthetic or natural origin. Because of their hydrophobic nature and lower volatility, HILs are considered an environmentally friendlier alternative to traditional herbicides, which often persist in the environment, contaminate groundwater and are toxic even to non-targeted organisms. Nevertheless, the scientific research on HILs is mainly focused on their effects on plants. In this thesis, the hormonal activity of selected HILs was tested using human cell lines. In addition, the ecotoxic effect of HILs on soil microorganisms was assessed using the analysis of phospholipid fatty acids (PLFA). To study the ecotoxic effect, two different types of soil were incubated with HILs in a 28-day experiment. The soils were characterized by a different management approach - the soils were treated or untreated with pesticides in the past. The effect of the content of soil organic matter and clay minerals on how HILs interact with soil microorganisms was evaluated. The residual concentrations of HILs were quantified during the soil experiment to assess the effect of the management approach applied in the past on the degradation rate of...
Study on stability of triazine based herbicides in water
Petrlíková, Kateřina ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The first aim of this thesis was to find a suitable analytical method for monitoring of stability of four s-triazine herbicides in water samples. Two columns - stationary phases C18, namely products of Waters and Astec were tested in HPLC system. The composition of ACN/H2O mobile phase was changed in the range from 90/10 to 60/40 (v/v). Baseline separation of prometone, propazine and prometryne was achieved on the Astec C18 column with mobile phase ACN/H2O 70/30 (v/v). This separation system was used for the study of stability. The stability of s-triazines was monitored in the period of six weeks. The samples of atrazine, prometone, propazine and prometryne water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples were measured in samples of water - water from Vltava, acidified water from Vltava, water from water tap and acidified water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples.
Oxidative damage to cellular components after oxidative stress induction by specific herbicides
Kramná, Barbara ; Wilhelmová, Naďa (advisor) ; Ryšlavá, Helena (referee)
Oxidative stress is caused by overproduction and overaccumulation of ROS (reactive oxygen species). This state is responsible for cellular damage during unfavorable environmental conditions such as drought, low temperatures, salinity. In order to directly study oxidative stress at tobacco plants (Nicotiana tabacum cv. Xanthi) I used specific herbicides, MV (methyl viologen) and 3-AT (3- aminotriazole). There were several markers used for monitoring oxidative damage to cellular components: DNA damage detected by a comet assay, lipid peroxidation, carbonylated proteins and modification of activities of antioxidant enzymes CAT (catalase) and APX (ascorbate peroxidase). Fluorescent microscopy documented changes in a redox state of tobacco cells and a specific signal for peroxisomes was observed after treatment with higher concentrations of MV and 3-AT. Application of both herbicides caused significant DNA damage, while they worked in a different concentrations, MV in µM and 3-AT in mM. Another convincing oxidative stress marker for MV was protein carbonylation. The inhibition of antioxidant enzymes CAT and APX was less significant when compared to the effects of 3-AT. Decreasing membrane stability proved to be an universal oxidative stress marker for both herbicides. On the other hand, lipid...
Influence of advanced oxidative processess on ecotoxicity of pesticides
Goma, Bernadette ; Procházková, Petra (referee) ; Zlámalová Gargošová, Helena (advisor)
The topic of this bachelor thesis is a study of the influence of advanced oxidation processes on the ecotoxicity of pesticides Metazachlor and Chloridazon. Both herbicides are commonly used to protect crops such as oilseed rape, turnips, chard or fodder beet against whole range of undesirable monocotyledonous and dicotyledonous plants. Application is most often on large areas and therefore pose a high risk to the quality of the environment. The possible influence on the representatives of producers and consumers of the aquatic ecosystem was monitored in the work. Solutions of pesticides, which were subjected to selected methods of treatment using advanced oxidation processes, were tested on aquatic organisms, specifically on crustaceans Daphnia magna and aquatic plant Lemna minor. From the results of individual tests, the ecotoxicological values of EC50 and IC50 were calculated and their ecotoxicity and thus the efficiency of oxidation processes in the removal of pollutants from wastewater were compared.
Pesticide glyphosate and possibilities of its determination
Stará, Kristýna ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
This bechelor thesis deals with determination of glyphosate employing capillary isotachophoresis technique. The literature review is devoted to pesticide, their distribution and use, properties and methods for the glyphosate determination, capillary zone isotachophoresis and its use. Experimental part focuses on the application of capillary isotachophoresis for determination of glyphosate, for determination of glyphosate in commercial preparations and testing of glyphosate sorption in soil.
Vliv herbicidu s-metolachloru na raná vývojová stádia raka mramorovaného
MATERNA, Jan
S-metolachlor is a substance belonging to the group of herbicides, widely used in agriculture to protect crops. This substance with the chemical composition C15H22CINO2 and is used as the pre-emergent herbicides to control unwanted weeds. The aim of this work was to evaluate the influence of s-metolachlor on mortality, behavior, growth, ontogenetic development, oxidative stress level and activity of antioxidant enzymes of early developmental stages of marbled crayfish (Procambarus fallax f. virginalis). The effect of s-metolachlor was evaluated on the basis of embryo-larval toxicity test. Early developmental stages of crayfish were exposed to three concentrations of s-metolachlor, 1.1 micrograms/l, 11 micrograms/l and 110 micrograms/l for 45 days. All tested concentrations significant showed higher mortality, delay of ontogenetic development, lower growth and changes in behavior (total movement distance and movement speed). Moreover, significant decrease in catalase, glutathione-s-transferase, superoxide dismutase concentration, and reduced glutathione levels at the two higher test concentrations (11 micrograms/l and 110 micrograms/l) of s-metolachlor were observed. No significant changes in oxidative damage (TBARS levels) were observed in all the tested groups. Based on the results of this study, early developmental stages of marbled crayfish can be recommended as suitable organisms for toxicity test and their use for biomonitoring of the aquatic environment by herbicides.
Metody a možnosti regulace plevelů v jarních obilninách
DVOŘÁK, Jan
The thesis focused on description and characteristics of spring wheat and barley and their life cycles. Thesis deals with the issue of very dangerous weed plants and deals with the possibilities of their regulation by using herbicidal preparations in the growth spring cereals. Weeds are problematic plants that negatively affect the quality of production and also the economy of cultivation. Part of the thesis is the evaluation of a small plot experiment, which was performed in the crop of the spring barley on the land of the company AGRO Dolní Bukovsko in the cadastral area of the village Sedlíkovice in the direction (of Veselí nad Lužnicí) and in the spring wheat on the land of the above mentioned company in the cadastral territory of the municipality of Radonice in year 2017. Results of weed frequency and economic evaluation of the experiment are presented in tables and graphs.
Certified method for evaluation of biological efficacy of controlled atmospheres and fumigation in silos using biotest kits: methodology for workers in DDD, agriculture and food industry
Aulický, Radek ; Stejskal, Václav ; Plachý, Jan
Evaluation of the efficacy of controlled atmosphere or insecticide fumigation treatment of stored commodities is very difficult when these materials are located in silo bins. The main difficulty is to take measurements and samples within the entire commodity (vertical-silo) profile. Until now, there are no standard procedures and tools that would allow the evaluation of efficacy of controlled atmospheres under such situations. These methodical deficiencies are some of the main reasons why t controlled atmosphere methods are not commonly used in practice, although they are – under many conditions - relatively cost-effective disinfection measures. This methodology is the first Czech set of procedures for the proper preparation, application and evaluation of bioassays that can be used for evaluation of the efficacy of controlled atmospheres and fumigation in silo bins cells. The methodology also shows some practical examples and experimental results on how to use bioassay. The certified methodology was prepared with the financial support of the NAZV agency and is the technological an scientific output of the project QJ1310057.
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