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Protection of virus free Saaz hop and hybrid varieties of hops against downy mildew in Trsice hop growing region
Vostřel, Josef ; Klapal, Ivo ; Kudrna, Tomáš
Praktické využití této metodiky spočívá v omezení napadení porostů chmele peronosporou chmelovou a snížení ztrát na kvalitě a výnosech chmele ve chmelařské oblasti Tršicko, kde podmínky pro pěstování chmele a tím i výskyt peronospory jsou odlišné oproti Žatecku, které se nachází ve srážkovém stínu Krušných hor a má tudíž aridnější klima. Pro zvýšení efektivnosti ochrany chmele proti peronospoře chmelové je nutné využívat prognózy výskytu a postřikové programy sestavovat podle náchylnosti pěstovaných odrůd. Ekonomika ochrany úzce souvisí s komplexním přístupem, objektivizací potřeby ošetření a minimalizací počtu zásahů. V období let 2005 - 2010 jsme vynechali z původně plánovaných 35 postřiků 8 ošetření chmele u ozdraveného ŽPČ a 6 aplikací u hybridních odrůd, aniž by byla negativně ovlivněna kvalita hlávek.
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Investigation of Complexes of Tebuconazole with Zinc
Jakl, M. ; Norková, Renáta ; Navrátil, Tomáš ; Jaklová Dytrtová, Jana ; Balík, J.
Tebuconazole is one of the most utilized triazole pesticides in agriculture. Its stability is highly affected by complexation with metals. Moreover, it creates more or less stable complexes with essential elements that become unavailable to plants. In the system with overbundant tebuconazole, an inert (very stable) complex with Zn was found. Elimination voltammetry wit linear scan was used for revealing of the electrode processes on the mercury surface. The relatively slow kinetically controlled step in tebuconazole/Zn complex formation indication indicates the great ability of Zn-tebuconazole system to react with more ligans. Therefore, multiligand Zn-tebuconazole complexes with other ligands are expected in the nature.
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Use of bio-food in school canteens: primary schools in České Budějovice
RUSFELOVÁ, Zuzana
School canteens can significantly influence children?s eating habits and can demonstrate them perfectly good principles in food selection. The main objective of this thesis is to analyze the interest of school management and pupils? parents in the introduction of organic food in school canteen menus. The questionnaire survey was targeted at primary school and their school canteens that lie in the statutory city of České Budějovice and its immediate surroundings.
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Effect of application of pesticides on soil biodiversity
VOKOUN, Josef
In the Czech Agriculture sprayers used a variety of manufacturers, which particularly differ construction of the main functional unit, which has a significant impact on pesticide application. Goal of this paper is to compare the mode of application of protective agents sprayer with and without air support and assess the impact of pesticides on the environment (biodiversity,soil) and activity sprayer.
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Effects of triazine based pesticides on fish
MALÝ, Vratislav
Influence of triazine based pesticide (Sencor 70 WG - active substance metribuzine) was assessed via biochemical and hematological blood profile determination of experimental fish. As experimental fish we used common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss ). Before rating the Sencor 70 WG pesticide influence on biochemical and hematological blood profile we accomplished a preliminary test to determine a concentration range and after that a basic acute toxicity test to determine 96hLC50 value. Both fish samples fingerlings were used for performing the tests. After 96hLC50 determination two groups of experimental fish (aged 1-2 years) were under this concentration and one control group without the substance. The test was processed according to the OECD methodology No. 203. Fish dissection was performed after the test. The increased amount of phlegm of water consistency on the body surface was found out. The fish were of dark colour in contrast with the control group. The ventricle was larger and containing transudate. An outstanding vascular profusion of internal organs in the ventricle was found out. Biochemical profile of the rainbow trout (Oncorhynchus mykiss ) experimental group under 96 hour acute operation of pesticide Sencor 70 WG (89,3mg.kg-1) proved significant lowering (p<0,01) of total proteins (TP), triglycerides (TRIG), aspartate aminotransferase (AST), amonnia (NH3), alcaline phosphatase (ALP) and Ca2+ in the blood plasma in contrast with the control group. Hematological profile of the same group proved significant lowering (p<0,05) of the number of erythrocytes (Er), haematocrit (PCV), and significant increase (p<0,05) of erythrocyte haemoglobin (MCH) value in contrast with the control group. Biochemical profile of the common carp (Cyprinus carpio L.) experimental group under 96 hour acute operation of pesticide Sencor 70 WG (250,2 mg.l-1) proved significant lowering (p<0,01) of total proteins (TP), triglycerides (TRIG), lactate dehydrogenase (LDH), Ca2+ and inorganic phosphate (PHOS) and significant increase (p<0,01) of glukose (GLU) and amonnia (NH3) concentration in the blood plasma in contrast with the control group. Hematological profile of the same group proved significant lowering (p<0,01) of the haematocrit (PCV), erytrocyte haemoglobin (MCH), mean erytrocyte volume (MCV) and number of leukocytes (Leuko) in contrast with the control group.
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The Influence of Pesticides on the Infectivity of Entomopathogenic Nematodes
NERMUŤ, Jiří
It is known that entomopathogenic nematodes rarely live in fields where pesticides and fertilizers are used. Because they are organisms with a high potential for biological and integrated pest control the thesis tried to determine the influence of pesticides on the infectivity and mortality of selected nematodes: Steinernema feltiae, S. arenarium and S. kraussei in water solution of some pesticides. The results are that preparations Vydate (a. i. oxamyl) and Sulka (a. i. sulphur) have the highest negative influence on both characteristics. These pesticides cause a mortality of 94.3 - 99.9 % and reduce infectivity by about 50 {--} 75 % (level 3). The following preparations may be identified as having higher potential for infectivity reduction: above all, Starane 250 EC (fluroxypyr), Sumithion super (fenithrothion), and Novozir MN 80 (mancozeb); on the other hand, Treflan 48 EC (trifluralin) significantly increases mortality. Another important observation is a fact that infectivity is significantly influenced only by concentration of pesticides, not by exposure time. During an experiment with enhacement of resistance to oxamyl (Vydate) I falling mortality and increasing infectivity of entomopathogenic nematodes were observed after five rounds.
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Toxicologically important pesticides in the regard of human health
VODVÁŘKA, Stanislav
There are an enormous number of known pesticides exceeding 10 000 substances. For more than 80 years these chemicals have been used to control pests including animals, seeds or parasitic fungi threatening agricultural, garden or forest plants, food or farming product reserves, industrial materials (textiles, leather, timber, etc.), and other animals as well as man. These substances are classified according to the type of use in pest control. The most important and prevalent groups involve insecticides, fungicides and herbicides. The other groups are of minor importance. Due to the high numbers of substances available, this work has been reduced and focuses on insecticides only, particularly on the insecticides showing the highest toxicity level for warm-blooded animals including humans, i.e. the insecticide substances that may be suspect in terms of abuse by terrorists. It has been proved long ago that some of the organophosphorous and carbamate insecticides show the highest toxicity level.
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