Fulltext search in archive

The effect of infection with Prunus necrotic ringspot virus (PNRSV) and Prune dwarf virus (PDV) on vegetative and reproductive growth of sweet cherry trees (Prunus avium L.) was investigated. Infected trees were smaller and the growth reduction was more severe in Lapins than in Sam; when trees were infected in the nursery (early) compared to an infection two years later in the orchard; and when trees were grafted on the dwarfing Inmil rootstock compared to the more vigorous Damil. Tree mortality after establishment in the orchard was not a problem and only one virus infected tree died during the 5-year observation period. Reduced vigour was accompanied by increased blind wood formation. While the infected trees had a higher generative spur density the total number of generative spurs per tree was less than in the virus free controls, thus reducing yield. In addition the germination of pollen from infected trees was reduced. In general PNRSV has little or no significant influence on vegetative or reproductive behaviour, while PDV significantly reduced both characteristics. The combined infection had dramatic effects, especially on the dwarfing Inmil rootstock with the susceptible cv. Lapins. After four years in the orchard 10% of the initially virus free trees were infected by PDV and 48% by PNRSV.

From the economic point of view the issue is comprehensive namely for its long-term character. At present, there is little experience in complexly understood economic calculations concerning the effect of climate change on forest management. Therefore a new methodology had to be proposed to solve the assigned task, i.e. to analyse the results of research on the effect of climate change on forest management. The issue is closely related to changes in production characteristics of commercial species, i.e. site quality and species composition or health conditions and rotation period of each species and stand. In this case it concerns with a higher proportion of deciduous species at the expense of conifers, namely spruce. This issue also includes the question of further afforestation of non-forest agricultural land, that means the question of land delimitation between agriculture and forestry.

A monitoring system for Cameraria ohridella males based on a synthetic sex pheromone was tested in the Czech Republic, Germany, France and Greece. From the obtained data on the insect phenology we concluded that in Central Europe C. ohridella typically has three generations per year. The pheromone monitoring can be used to detect the pest when it appears in uninfested areas and is also suitable to determine population densities.

A rapid, easy to handling and sensitive RNA preparation procedure, RNA release protocol was described here for the detection of Apple stem pitting virus (ASPV) and Apple stem grooving virus (ASGV) by RT-PCR. Comparing total RNA extraction protocol, RNA release protocol give raised similar rate of ASPV and ASGV detection within the field-grown apple cultivars. Among sampling plant tissues, the bud leaf and leaf (during blossom) were showed efficient tissues for the routine detection, regardless the using RNA preparation procedures.

We characterized the genetic diversity of seventy-three C. lindemuthianum isolates collected from 10 different countries by Amplified Fragment Length Polymorphism (AFLP) analysis. The results of this research highlighted the fact that there is huge variation in the genetic diversity between isolates from different countries. The molecular profile of the isolates showed correlation with geographic origin of the isolates.

B. salicis was monitored in willow stands, sampling trees with and without watermark disease. The study focused on Salix alba and S. fragilis. B. salicis - presence was shown not to be restricted to diseased trees. With a B. salicis-specific PCR, B. salicis was frequently detected in the wood of healthy willows. This phenomenon was further studied with PCR-DGGE of endophytic bacterial populations in healthy and diseased willow. B. salicis concentrations were fluctuating during the year, synchronized with tree activity. Water stagnation in the wood as in winter was associated with a high B. salicis concentration, while the sap stream in active trees drained B. salicis from the wood vessels towards the leaves. We concluded that disease risk can not be assessed by testing the presence of B. salicis.

This paper deals with the changes in soil active acidity, mobile aluminium, base saturation, iron and manganese under the influence of quicklime (QL), mixture of soft lithothamnian limestone (SLL) and dolomite (D), and special natural amendments (SNA) based on zeolite tuff. Investigations were carried out on pseudogley of mesoelevations, dystric. The four-year trial was set up according to the Latin rectangle method with 18 trial treatments in four replications. While SNA based on zeolite tuff had little effect on changes of the studied parameters, traditional lime materials (LM), owing also to the fact that they were applied at several times higher rates, had a very positive effect. Soil acidity, iron and manganese were reduced under their influence, mobile aluminium, particularly under their higher rate, was fully blocked or reduced within tolerable limits, and base saturation was raised to a satisfactory level. Effects of SNA depended on the ratio of zeolite tuff and the lime component in them. It could be presupposed that their main efficiency happened in the domain of ion exchange with a positive impact on soil fertility.

Seven cultivars of common buckwheat were tested in field trials under two levels of nitrogen fertilisation on two experimental sites during 1998-2000. The aim of the experiments was to evaluate the influence of cultivar, nutrition and year on main technological quality parameters (thousand achenes weight, volume weight, proportion of fractions on sieves 4.5 and 4 mm, proportion of husks and yield of groats). The differences were observed between buckwheat cultivars in all observed parameters of technological value. Nitrogen fertilisation before sowing (50 kg.ha^-1) did not influence any parameter. On the contrary, buckwheat technological value was influenced by sequence weather (particularly rainfalls) during flowering and achenes formation periods (July). The influence of year was manifested especially on development of endosperm and husks of achenes. Better growing conditions on experimental site Uhříněves caused lower values of volume weight, lower proportion of pericarp (husks) and considerably higher proportion of fraction over 4.5 mm.

Recently we can mention in the CR a step by step enterprise number increase in the area of production, transport services, services and financial organisations, which practically apply internal departments of controlling or audit into their managerial structures. That is why it is required to dedicate a wider publication space to the information on the role and principles of managerial instruments, which are provided by controlling and Internal Audit for business administration and financial management. The goal is to ensure a higher quality of preparation or response on the still emerging forms of our enterprises co-operation with foreign business subjects and to match step at the level of building and in particularly in effectiveness of business informational systems usage for managerial process (especially for planning and decision making procedures control) in all areas of business functions. Internal controlling instruments application and using results of risks evaluations by internal audit simultaneously contributes to the improvement of level and effectiveness of intra-enterprise monitoring as a modern conception of control usage in business management. Management level increase and increase of management competency are the conditions of ensuring our enterprises competitiveness.

The paper addresses the behaviour of Czech farmers in the frames (structures) created by the agricultural policy in Czechia during the period of the Czech agriculture revitalization. The theoretical background of the paper is formed by the duality of actor and structures. The text considers the ideas embedded in the rules of agricultural policy in investigated period as they are confronted with actual behaviour of the Czech farmers. The main assumption is that the circumstances of agricultural policy should primarily increase the competitiveness of the Czech agriculture. Because this issue is a new one, the qualitative approach to deal with these problems was exploited. In-depth (less standardized) interviews with representatives of six farms were conducted. These farms are typical by various strategies of action. The results focus on information about the level of systematic knowledge of agricultural policy, about the specific reactions to particular areas of this policy (incl. farmers evaluation of particular measures related to Czech integration into EU) and about experiences related to the SAPARD program implementation.

This study deals with the founding and development of agrarian political parties and movements in selected postcommunist states (with the emphasis put on the Czech party system in the early 1990's). The topic is discussed from the point of view of classic political science theories, namely the historical conflict approach of Stein Rokkan and Seymour Martin Lipset, complemented with Derek Urwin's theory regarding emergence of agrarian parties as a means of defense of country against urbanization. The results of research into the urban - rural cleavage and its influence on the genesis of agrarian political parties in selected post-communist countries after 1989 seem to support the above mentioned theories (even though those were originally formulated for a much earlier period when the Western party systems were first coming into existence. These can be applied also to the Czech environment, where several profession-based political parties were established in the early 1990's, some of which were concerned with the defense of peasants' and farmers' interests. The attempts to create profession-based parties in the Czech political system were destined to fail for several reasons. The first was a striking ideological profiling of the bipolar party spectrum, causing general parties to pick up the themes and voters concerned with economic recession, and radicalization of electorate. The second reason lied in the diminishing numbers of potential voters, a result of agriculture modernization and general urbanization of society, which caused that the city-country conflict was reflected in the election results only marginally. The result was similar to other post-Soviet states, with a specific exception of Poland: agrarian parties and movements lost their former influence.

The aim of this study was to develop a protocol for production of polyploid M1-generation plants of Viola × wittrockiana Gams. Two variants of colchicine treatment were compared for their efficiency. Early detection of novel ploidy levels was achieved by screening of stomata size, leaf index value (leaf blade length/width), and other morphological characteristics of the M1-generation. Secondary screening for novel ploidy levels was performed by flow cytometry (FCM). Hexadecaploid, aneuploid, and mixoploid plants were successfully identified by FCM.

The hypothesis, that hypoiodemia of goats causes such a compromise of the immune system, which during subsequent Toxoplasma gondii infections results in clinically more pronounced signs of toxoplasmosis, was verifying in laboratory mouse. Hypoiodemic mice (fed by wheat and supplied by water), normoiodemic mice (fed by wheat and supplied by water containing 1.25 mg KI/l) and the majority of standard mice (fed by commercial grain mixture containing 0.83 mg I/kg) were experimentally infected with T. gondii oocysts or tachyzoites. The susceptibility to acute T. gondii infection was evaluated according to mortality rate. As a criterion of cell-mediated immune function has been chosen the spleen-lymphocyte transformation test (LTT). We observed no difference in LTT between hypoiodemic and normoiodemic mice infected with T. gondii oocysts or tachyzoites and no difference in mortality of both infected groups. Four days after the exposure to 100 tachyzoites of T. gondii (K24 strain), all experimentally infected groups of mice showed statistically significant decrease (P = 0.004) in spleen cells responsiveness to stimulation by all mitogens used - as compared to non-infected standard mice group. Reduced responsiveness of cells was probably caused by T. gondii infection itself - the relation to iodine deficiency has not been found.

The results document changes in the herb vegetation of a South-Moravian floodplain forest in the period of 1978-1997. It is shown that hydrological measures strongly changed the floodplain forest in the area of the Dyje river near Lednice na Moravě. The herb vegetation in the area of the confluence of the Morava and the Dyje rivers was conserved nearly unchanged after artificial floods.

Natural regeneration is an important part of close-to-nature forestry. However, natural regeneration also has either natural or technological limits. Among the most important natural limits are a low sum of precipitation and site type. The study concentrates on Žatec region where the long term average sum of precipitation is only 440-450 mm per year. Dry periods during the vegetation time are quite frequent. The study was conducted on clear cut area, stand edge, shelterwood area and stand interior. The results showed the highest population densities in a shelterwood system, the lowest in the stand interior. On the other hand, the dry seedling biomass is lower for seedlings from shelterwood area than from clear cut area.

ocids are commonly found to be a persistent pest in structures of grain stores. Grain residues are potential pest reservoirs that serve as sources of grain re-infestation. Weight losses caused by psocids on broken wheat kernels were measured. Average weight loss of grain samples was 9.7% after 3 months of Liposcelis bostrychophila infestation. The weight losses were positively correlated with progeny production.

The molecular basis of organ specificity in plant diseases is little characterised. Downy mildew of Arabidopsis caused by the oomycete Peronospora parasitica is characteristically a leaf disease. Resistant host genotypes recognise the pathogen in a gene-for-gene dependent manner and respond with the production of H₂O₂ and the execution of a genetically programmed hypersensitive cell death (HR). We inoculated the roots of Arabidopsis genotypes Col-0, Ws-0 and Wei-0 with the NOCO and WELA races of the pathogen and compared the responses with those observed in infected leaves. Combinations of incompatible genotypes of host and pathogen showed the expected responses of an oxidative burst and the HR in leaves but, surprisingly, roots showed no signs of active defence and appeared completely susceptible to all the P. parasitica isolates tested. RT-PCR showed that the R genes RPP1 and RPP13, which mediate resistance in leaves to P. parasitica isolates NOCO and WELA, respectively, were expressed in leaves as well as in roots. Similarly, NDR1 and EDS1, two components of RPP1-mediated gene signalling pathways, are also expressed in both tissues. Thus, we show for the first time that expression of R genes and at least some of the known downstream components of the signalling cascade are not sufficient for the induction of avirulence gene-mediated defence mechanisms.

In the framework of the study of the mode of action of biocontrol agents (BCAs) it is important to know if BCAs areantibiotic-producers. Epicoccum nigrum 282 and Candida sake CPA-1 are BCAs effective against post-harvest pathogensof stone and pome fruits. The antibiotics produced by these BCAs and the relationship to biocontrol were studied.Production of antibiotics by E. nigrum in in vitro cultures began at 5 days of incubation being maximal at different timesdepending on media used. However, no antibiotic was detected when E. nigrum was grown in a solid state-fermentationsystem or in peaches. In the case of C. sake, no antibiotic was detected either in vitro, in liquid fermentation culturesof the yeast, or in apples.

Surveillance on cyst nematodes in Slovenia started already in 1963. We have found Globodera rostochiensis for the first time in 1971 and for the second time in 1975 (two cysts). In 1999 cysts of yellow potato cyst nematode were found again. A small hot spot was detected along the Slovene Austrian border. Cysts of Globodera rostochiensis were extracted from samples taken in 1.6 hectare field. In 2001 we surveyed 194 fields with the surface of 468.29 ha. We discovered another hot spot of Globodera rostochiensis in the Central Slovenia. Cysts of Globodera achilleae are seldom discovered in Slovenia. During the period between 1980 and 2000 we extracted altogether 206 cysts. In 2001 we found three fields where we extracted at first seven cysts. With more detailed survey we extracted another 30 cysts. In a few soil samples taken from the imported potatoes from Italy we have intercepted cysts of Globodera pallida. For that reason shipments were returned. In a similar way in 2002 shipments from Croatia were returned because of G. rostochiensis presence. Specimens of Globodera rostochiensis and G. achilleae species found in Slovenia were morphometricaly handeled.

Arabidopsis thaliana accessions were inoculated with incompatible isolates of downy mildews, following pre-inoculation with compatible Albugo candida. Three isolates of Hyaloperonospora parasitica subsp. A. thaliana, an isolate of H. parasitica subsp. Brassica oleracea and one Bremia lactucae (lettuce) isolate were included. All downy mildews sporulated on A. thaliana, suggesting A. candida suppresses broad-spectrum downy mildew resistance. The white rust resistance gene, RAC5, is being investigated. The resistance phenotype associated with RAC5 seems not to involve a hypersensitive response. RAC5 has been mapped telomeric of nga106 on chromosome 5, in a region lacking NB-LRR genes, the most common structural class of resistance genes known in A. thaliana.

Effect of temperature on growth and antagonistic ability of Trichoderma spp. isolated from local strawberry culture and commercial product, against Rhizoctonia solani, strawberry pathogen, was studied in vitro. Trials were carried out twice, at 10, 25 and 30°C. Inhibitor effect was evaluated by radial growth measures of established duals on PDA's dishes, using Royse and Ries formula, to evaluate the percentage inhibition of radial growth. Design of dishes was a randomized complete block, considering 10 replicates. Data were analyzed statistically by two-way analysis of variance. The objective has been to determine the most competitive Trichoderma strain and the best temperature that produce the inhibiting effect on the pathogen growth. Local strain has the best behavior at 10 and 25°C.

Both spring and winter barley were sown after a forecrop of winter rape. Three registered model varieties of six row and two row winter barley reached in the period 1999-2001 significantly higher yield than three model varieties of spring barley. Two row spring and winter varieties produced significantly higher thousand grain weight (TGW) than six row winter barley. The resistance to diseases and lodging (correlation coefficient with resistance to powdery mildew represent 0.68**, rust 0.72*, lodging 0.61**) was the most important factor determining the yield. Resistance to rust has influenced sieving on 2.5 mm, correlation coefficient reached value 0.88**. No significant differences were determined in any malting quality parameter when varieties of two row winter barley variety (Tiffany), and spring barley varieties (Akcent and Tolar) were compared. Variety Tolar reached higher parameters for friability and a beta glucan content. Between years, significant differences were found in following parameters: protein content and apparent degree of attenuation. Due to reduction of area sown with spring barley and reduced yield potential, two row winter barley varieties with comparable malting parameters are recommended to be cultivated as the reserve crop for malting barley industry demands.

The paper is focused on the evaluation of the possibilities of analysing the relations between economic and financial indicators of farm businesses by the application of multivariate statistical methods. It also indicates the possibilities of the construction of a general economic indicator of business effectiveness.

The foreign agri-food trade has showed an unsuitable development for the Slovak Republic during the 1999-2001s. The negative balance for the competitive commodities is increasing. These are the commodities for the production of which the SR has suitable natural conditions. The contribution deals with the selected competitive commodities in the kilogram prices. The study shows the decreasing tendency of kilogram prices in import and the increasing tendency in export. Higher export price is the consequence of the higher value added and thus also higher revenues.

The study deals with the comparison of financial situation of farms in the Czech Republic. Three groups of farms are compared - co-operatives, business companies and individual farmers. The data were analysed within the years 1994 and 2000. The analysis of financial situation was done by the means of indexes describing liquidity, activity and profitability as well as some other additional indicators such as labour productivity and costs levels etc.

The studies aimed at monitoring development of phagocytic and bactericidal activity in carps in the course of their ontogenetic development. The studies were performed using the techniques described by Mantur et al. (1986a, b), adapted to fish. Results were expressed in thrombocyte phagocytic index (Ipt), percentage of phagocyting thrombocytes (%tp), percentage of ingested bacteria (%bp) and in the index of intracellular killing by thrombocytes (Ibt). Number of thrombocytes was also examined using the technique of Dessi. Results of testing thrombocyte capacity to ingest the standard Staphylococcus aureus 209P strain showed that Ipt and %tp increased gradually in carps between the age of 3 and 17 months. In older carps, 19 to 29 months of age, as well as in spawners the growth in activity paralelled the ontogenetic development within Ipt values while %tp values remained at a similar level. Phagocytic activity of thrombocytes expressed in Ipt was reflected also by %bp values, which was particularly evident in fish aging 23 months to 5 years. In the case of Ibt, values of the index were not related in any way to stage of ontogeny or sex of the fish. Number of thrombocytes in carps aged 3 months to 5 years was increasing in parallel to their ontogenetic development.

The optimization study was carried out in the part of the Jeseníky Mts. region in order to find the optimum variant of a forest road route. The ROADENG system was used for determining the Jezerná forest road design with use of projection above the digital elevation model of terrain. Particular variants of the forest road route were calculated and analyzed on the basis of environmental approach. The final report recommended one of the variants for the final elaboration of project documentation and for construction.