Fulltext search in archive

Dual inoculation of peat based horticulture substrate with a mixture of four species of arbuscular mycorrhizal fungi and fungal biocontrol agent Trichoderma harzianum showed a significant positive effect on the growth and flowering of cyclamen plants. Inoculation substantially decreased plant mortality caused by spontaneous infection by the fungal pathogen Cryptocline cyclaminis. Plant mortality was also reduced by separate inoculation with arbuscular mycorrhizal fungi. Both separately inoculated agents positively affected the plant growth, although to a lesser extent. Very few significant effects of inoculation were observed on the growth of poinsettia plants cultivated from cuttings. Use of arbuscular mycorrhizal fungi together with the introduction of Trichoderma for inoculation of horticultural substrates is suggested to alleviate the inevitable effects of various stresses during the cultivation of horticultural crops.

The development of soil limiting values of the protection of the quantity and mainly quality of the crop production tends from empiric values towards critical values, based on ecotoxicity. We present an attempt to derive transfer functions by the means of multiple regression analysis. The substitution of trace elements contents in crops in the prediction equations for fodder or food standards or phytotoxicity limits satisfies the present ecotoxicological demands. We preferred polyfactor relations to simple ones. The exceeding of reference values must be verified by the determination of the hazardous transfer in the field. Therefore the reference values are called testing values. They were derived especially for Cd, Pb, As, Cu, Zn, Ni and Mn. For some trace elements, only protective values can be set up (especially for Cr, Hg, but also for Tl, Be, V). They reflect minimum values that guarantee growing crops without any risks. Experimental data (pot trials) were compared with results obtained in field investigations. The resulting critical values were also compared with the values proposed in Germany.

In field experiments conducted on loamy luvic chernozem (170 m altitude, 48°34' N 17°45' E), the effects of undersowing time (5 days after maize was sown and into emerged stand) of lucerne, red clover and sainfoin on silage maize dry matter have been studied. The total dry matter yields were affected by time of undersowing of clover crops. The stands undersown after emergence of maize gave higher yields than former time of undersowing. The late time of undersowing improved conditions for growth of maize and formation of its yield. The number of maize plants had already insignificant effect on yields there. The dry matter weight, height, and number of maize plants and dry matter weight of weeds were main factors of formation of the total yield. The depressive effect of weeds on total yields was applied indirectly particularly through the decrease in the dry matter weight of maize plants. The path analysis in spite of the insignificant effect of clover crops undersown on total yields indicated some differences in the formation of yield. The number of maize plants reached the significant level of effect on yield only at stands with red clover undersown. On the contrary, the negative correlation of weeds dry matter weight with the number of maize plants reached level of significance in stands with lucerne undersown only.

The study was undertaken in Croatia, Czech Republic, Hungary, Poland, Slovakia and Slovenia laying between Baltic and Adriatic seas on 610 402 km². Mycobacterium bovis infection was diagnosed in 70 animals belonging to 17 species other than cattle. The set of wild animals comprised 12 European bison (Bison bonasus), one red deer (Cervus elaphus), five wild boars (Sus scrofa), and one European wild goat (Capra aegagrus) bred in a game park. Further positive animals included two farmed red deer (Cervus elaphus) and one bactrian camel (Camelus ferus) owned by a circus. The infection was also demonstrated in 18 domestic animals belonging to 3 species living on farms where bovine tuberculosis was diagnosed in cattle. This set included 12 domestic pigs (Sus scrofa f. domestica), two domestic sheep (Ovis ammon f. aries), and four dogs (Canis lupus f. familiaris). The set of animals bred in zoological gardens consisted of 30 animals belonging to 9 species as follows: three bison (Bison bison), four tapirs (Tapirus terrestris), one cassowary (Casuarius casuarius - isolate identified by the biological assay in guinea pigs only), eight sitatungas (Tragelaphus spekei), three elands (Taurotragus oryx), one gnu (Connochaetes taurinus), eight reticulated giraffes (Giraffa cameloparadlis reticulata), one puma (Puma concolor), and one Vietnamese pot-bellied pig (Sus bucculentus). Although, considering the population sizes, absolute numbers of the infected individuals are rather low, wild animals or such animals bred in captivity should be regarded as possible reservoirs of the causative agent of bovine tuberculosis. Tests for bovine tuberculosis are therefore necessary before transportation of all wild animals. Any lesion arousing suspicion of tuberculosis found on necropsy of wild animals must be laboratory examined for the presence of mycobacteria.

The paper studies the effect of a single use of a textural fraction of dolomitic limestone (5.1 t per ha) on soil reaction (pH/KCl and pH/H2O) and the content of exchangeable Ca and Mg (in the soil layer of 0-30 cm or in F, H and A horizons) during a 6-year experiment under a mature Norway spruce stand and a 4-year experiment on a clear-felled area. The increase in pH culminated in the 3rd or in the 3rd-6th year of the experiment. Maximum effects were achieved applying the fine fraction of a particle size £ 1 mm. The coarse fraction of a particle size > 1 mm showed virtually negligible effects. The increase in Ca and Mg content culminated in the last 6th year of the experiment. Maximum effects were achieved applying fine fractions again. The effect of the coarse fraction was also virtually negligible. After 6 years, ma-ximum increase in all values under study occurred in the upper narrow F horizon while the increase rapidly dropped downwards.

The article deals with issues of non-market forest services. There is a persistent issue complicating the quantification of adequate subsidy to forest owners - non-existence of market with such forest services. Forest services financing can be made objective by implementation of the following steps: 1. Earmarking of non-market forest services that are becoming market subjects gradually. 2. Earmarking of non-market forest services that create a secondary product of wood production function. 3. Quantification of demand for services. 4. Quantification of costs necessary to cover the demand for those forest services. 5. Quantification of losses caused to forest owners by restricting their economic activities.

The benefits arising from adoption of information and communication technology by farming businesses are explored, and the prospect of a digital divide appearing in the UK agricultural sector is discussed, drawing on results of research at the University of Plymouth. It is proposed that countries in Central and Eastern Europe will be subject to the same phenomenon, and that the potential disadvantage suffered by non-adopters of this technology will be sufficiently severe to justify both policy intervention and further research.

Recent literature and research on social capital has demonstrated the economic importance of social features, such as trust and norms that facilitate cooperation. This article focuses on the role of social capital in the context of the Czech agricultural sector. Obtaining credit, sharing machinery, and proliferating information serves as examples where an awareness and reliance on the social capital of rural communities matter. By forming groups and strengthening existing networks, Czech farmers can improve their productivity, as well as their welfare. The article concludes by warning that the Czech state cannot invest directly in social capital, but should create the necessary legal and economic incentives to encourage the formation of social capital.

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.

An outline of past achievements in plant pathology in the CR and main recent problems of Czech plant pathologists are given. A description of the present state in plant pathology in the CR is preceded by data on the structure of CR, on its agriculture, research and development. The outstanding feature of the Czech agriculture is large-scale production. However, the CR still lags behind the EU in yields per hectare. Compared with the EU member states, the CR devotes less money (less then 0.7% of GDP) to research and development (R&D). The trend of state subsidies to R&D in the agriculture sector in current prices is stagnant. It represents an actual decline in the fixed prices. In the Czech Republic, approximately six hundreds persons are professionally engaged in plant health. It represents 6 professionals per 100 hundreds citizens in the CR. Around 160 persons deal with the research and/or teaching of plant pathology. Public service in the field of plant health (advisory work, extension or outreach activities) is one of the weak links in the system of plant health care in the CR. The reason is the lack of commitment for this field of plant health care activity together with absence of sufficient financial support. Minimum requirements for education should be set on advisors and provider of services in the field of plant health at the EU level. In the CR, there exists still some gap in scientific expertise of nematology and integrated pest management. The Czech Lands are proud of the role of some Bohemian and Moravian scientists who have been prominent in the development of plant pathology and related disciplines. These include: AUGUSTUS CARL JOSEPH CORDA and FRANTIŠEK BUBÁK in mycology, GREGOR JOHANN MENDEL in genetics, FRANTIŠEK KRÁL in bacteriology, BOHUMIL NĚMEC and EDUARD BAUDYŠ in plant pathology.

Using the Ames bacterial mutagenicity test and an in vivo micronucleus test, we investigated the antigenotoxic effect of ellagic acid on the genotoxicity of three mutagens: amino-methylimidazo-quinoline (IQ), aflatoxin B1 (AFB1), and N-nitroso-N-methylurea (MNU). Ellagic acid is a naturally occurring phenolic compound which is found in a variety of soft fruits and vegetables. The effect of this compound on the immunosuppressive activity of mutagens was followed in vivo by the chemiluminescence test. In the Ames assay, ellagic acid at concentrations of 300 and 30 μg/plate demonstrably inhibits the mutagenic activity of two indirect mutagens: IQ and AFB1. The concentration of 300 μg/plate had the strongest effect on mutagenicity of all concentrations of IQ in strain TA98 of Salmonella typhimurium, whereas in strain TA100 concentration of 30 μg per dish of ellagic acid was more effective than 300 μg per plate. Also in combination with different concentrations of AFB1, ellagic acid proved to be a strong antimutagen. In this case the lower of the two effective concentrations - 30 μg/plate - had a much greater antimutagenic effect on both strains tested than 300 μg/plate. In combination with the direct mutagen MNU, ellagic acid did not show any marked antimutagenic effect at most of the concentrations tested in strain TA100. Only the highest concentrations of ellagic acid reduced the mutagenic effect of MNU weakly and only in combination with two lower concentrations of MNU. In the micronucleus test, three-day oral application of ellagic acid prior to the applicaton of AFB1, IQ, or MNU, respectively, markedly reduced the numbers of micronuclei induced by these three mutagens in polychromatophilic erythrocytes of mice. Chemiluminescence test with mouse granulocytes proved that ellagic acid not only prevents the inhibitory effects of mutagens on free oxygen radicals and hydrogen peroxide production, but that this production is stimulated by ellagic acid in combination with mutagens even to a greater extent than by ellagic acid alone. From these results we can deduce that ellagic acid repairs strong immunosuppressive effects of all mutagens applied.

Isolates of Fusarium oxysporum f.sp. ciceri from chickpea (Cicer arietnum L.) can be characterized as races and wilt and yellowing pathotypes by pathogenicity tests on varieties of differentials chickpea. This study shows that, DNA bands generated by RAPD-PCR can be used to assign Fusarium oxysporum f.sp. ciceri isolates to pathotype and pathogenic race.

Small G-proteins (RAC and RHO) are known to be involved in regulation of superoxide (O₂^*-) production and the assembly of actin fibres. These processes are known to be crucial for accessibility and inaccessibility of barley cells to the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh). Using a candidate RT-PCR approach six Rac-related cDNA-clones were isolated from barley. The transient knock-down of RacB led to a remarkably lower penetration efficiency of Bgh into susceptible barley lines (Mlo/Ror1). Surprisingly the inhibition of RacB expression had no effect in the double mutant line A89 (mlo5/ror1). This led us to the assumption that the RacB-dsRNA effect is dependent on functional ROR1 (such as mlo5-mediated resistance). Vice versa, overexpression of constitutive active RACB-V15 in the susceptible line Pallas resulted in hypersusceptibility to Bgh. Thus, we conclude that RACB is a signal transduction protein functional in the accessibility of epidermal barley cells to Bgh.

The antifungal activity of water extracts of dried leaves of folded blackberry (Rubus plicatus W. et N.), walnut (Juglans regia L.), black currant (Ribes nigrum L.), and aspen (Populus tremula L.) was assessed in the in vitro experiment. The tested fungi were Alternaria alternata, Botrytis cinerea, Rhizoctonia solani, Fusarium culmorum, F. oxysporum and F. solani. It was found that all tested extracts inhibited the development of A. alternaria and F. oxysporum, whereas the strongest inhibiting effect was exhibited by extracts of aspen (A. alternata and F. oxysporum), black current (A. alternata) and folded blackberry (F. oxysporum). The tested extracts had no effect on B. cinerea.

The structure of crop production (areas under crops, crop yields, fertilization) in 15 agricultural farms in potato-production and mountain regions of the Czech Republic was analyzed to evaluate the relations between NPK fertilization level, percentage of perennial forage crops on arable land and grain yields as the basic indicator of crop production output. A multifactor analysis based on simple regression equations indicated direct relations between the two above-mentioned factors and yield. Correlation and regression analyses demonstrated a close correlation between grain yields and percentage of perennial forage crops on arable land especially when lower nutrient rates in fertilizers were used (below 100 kg NPK.ha arable land). This relation was expressed for the whole set of initial data by the equation: Grain yield t.ha^-1 = log² (NPK rate in kg.ha^-1 arable land + X% of perennial forage crops). The coefficient of perennial forage crop effect (X) in the range of 0-1.47 can be explained by soil enrichment with nitrogen, mobilization of other nutrients, improvement of soil structure and reduction in the weed infestation of soil. The effect of perennial forage crops on grain yield increase was quantified (estimated) from the whole set of data using the above equation at X = 0 by the value +0.42 t.ha^-1. The yield increase per 1 kg NPK.ha^-1 of arable land amounts to 0.0501 t.ha^-1, i.e. every 1% of forage crops on arable land increases the grain yield by 0.023 t.ha^-1 within the set. The relation between actual and theoretical yield of the whole set is demonstrated by correlation coefficient (r = 0.9332) if the effect of perennial forage crops is estimated by coefficient X = 0.95, if the effect is estimated by coefficient X = 1.47, the correlation coefficient is even higher (r = 0.9977).

A method of growth analysis was used to evaluate the yield results in experiments conducted during years 1999-2001 on School co-operative farm in Žabčice. In sequential terms of sampling from two potato varieties with different duration of growing season, the effect of leaf area index (L, LAI), on yield of tubers in soils contaminated by cadmium, arsine and beryllium, was evaluated. From a growers view the phytotoxic influence on development of assimilatory apparatus and yields during the growth of a very-early variety Rosara and a medium-early Korela were evaluated. These varieties were grown under field conditions in soils contaminated by graded levels of cadmium, arsenic and beryllium. The yields of tubers were positively influenced by duration of growing season and increased of leaf area index during three experimental years. On the contrary, graded levels of heavy metals had negative influence on both chosen varieties. The highest phytotoxic influence was recorded of arsine and the lowest of cadmium. Significant influence of arsenic and beryllium on size of leaf area index in the highest applied variants was found. The influence of experimental years on tuber yields was also statistically significant.

The effect of sewage sludge application on three soils of different properties (Chernozems - location Suchdol, Luvisols - location Červený Újezd and Cambisols - location Humpolec) was investigated in pot experiment and the accumulation of Zn in above ground biomass of oat as well as availability of Zn released by 0.01 mol/l CaCl₂ was evaluated. Stabilised sewage sludge was obtained from three wastewater factories in Czech Republic. Sewage sludge has been preincubated with addition of limestone and lime (7% of Ca w/w of sludge dry solid) in aerobic and anaerobic conditions and tested in pot experiment. The highest Zn mobility reduction was found at Humpolec soil. Sludge amended by lime and limestone reduced available Zn content in this soil (at sludge III by 86% after limestone and by 71% after lime application). Considerable reduction of Zn in plant showed in Humpolec soil treated by sludge with lime (by 20% compared with soil treated by nonincubated sludge - control) and limestone (by 30% after anaerobic incubation compared to control). The positive incubation and treatment effect was not confirmed in the other soils. Available Zn in Humpolec soil showed the strongest correlation among all soils with total Zn content in plant (at aerobic treatment R² = 0.66 and at anaerobic R² = 0.83).

For 17 cultivars of winter wheat (Triticum aestivum L.) different vernalization and photoperiod responses were detected. The effect of photoperiod sensitivity was not significantly changed by vernalization; different vernalization responses were probably due to the presence of multiple alleles at Vrn loci. The delay in heading depended on the vernalization deficit exponentially: y = Parameter (1) + (y0 - Parameter (1)) × EXP (Parameter (2) × (x - x0)). The dependence was shown to be general and significant for the given model in all the studied cultivars. Individual regressions characterised responses of cultivars to a deficit of vernalization treatment. Cluster analysis according to the characterisation obtained (full vernalization requirement, minimum vernalization requirement, insufficient vernalization and parameters of the dependence) showed the relationships between cultivars and enabled their grouping by similar profiles of vernalization, and, possibly, of photoperiod response. In individual cultivars, an attempt was made to use the model to predict performance for some agronomic traits.

The task of applied research is not only to acquire new knowledge, through which it contributes to the development of economy, to the consumer protection or to the training of qualified experts. For state-supported veterinary research, this means striving to protect people's health against diseases transmitted from animals, food-born diseases, contamination of feed and foodstuffs by toxic xenobiotics, a reduction in food quality through the use of low-grade raw materials and an adverse effect of environmental pollution. The territory of the state must be protected against the infectious diseases and animals against the negative effects of environment and technologies which often strive irresponsibly for the highest profits without regard for the consequences. The contributions of the Veterinary Research Institute, Brno, and other Czech research facilities to increasing knowledge on cattle health and reproduction are documented by the list of 105 references of papers published in peer reviewed journals since 1992. This article is available on http://www.vri.cz/vetmed.asp and the reprints of cited references can be requested by e-mail to <vri@vri.cz>

Superoxide dismutase (SOD) isoenzymes of the rumen bacterium Streptococcus bovis 4/1 were studied. Native PAGE showed a single band of Mn-SOD, unaffected by 10 mM cyanide or 5 mM hydrogen peroxide under both aerobic and anaerobic growth conditions. When the metals were removed from the growth medium by Chelex 100, the addition of manganese increased enzymatic activity, while addition of iron inhibited SOD activity. Changes in Mn-SOD and glutathione peroxidase (GSHPx) activities evoked by paraquat and increased values of TBARS indicated that these enzymes were not able to sufficiently prevent oxidative stress at given paraquat concentrations.

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.

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.

The aim of this paper is to summarize the results of the EU Phare ACE research project P97-8158-R, "Micro-economic analysis of farm restructuring in Central and Eastern Europe", that tries to fill the gap of theoretical as well as empirical research into the implications of continuing and evolving farm restructuring in CEECs on the efficiency of the agricultural production sector and the development of rural areas by focusing on the economic decisions and perspectives of farm operators, asset owners and rural households. For this purpose, surveys among family farms and farm enterprises were carried out in 2000 in Albania, the Czech Republic and Slovakia.

This contribution deals with the differentiation of agricultural enterprises, with focus on the declining enterprises as the most troublesome. In 2000, these businesses generated about 47% of the total loss in agriculture. In this respect, the methodological procedure was also used for the purpose of tipping out the highly unprofitable enterprises. The economic and financial analysis is focused on evaluation of the achieved results expressed in basic economic indicators. The analysis refers to the cause of agricultural enterprises decline. The different dynamics of restructuring process of agricultural production confirm the marked difference of results characteristic for declining enterprises with growing year-on-year loss, increasing costs, decrease of own capital, high indebtness and dependence on the foreign sources.

The incidence of Zucchini yellow mosaic virus (ZYMV) was monitored in the south Moravian region of the Czech Republic during 1997-2001. Crops of gherkin, squash, zucchini and cucumbers were found infected with ZYMV, manifested by symptoms of severe stunting and yellowing with deformed leaves and fruits. Twenty to eighty percent of infected plants were recorded. Six isolates of ZYMV from four localities were differentiated on indicator plants; three of them were maintained as being typical for differences in pathogenicity. Overwintered weed species were tested for the presence of the virus. ZYMV was detected by ELISA in one plant of Tripleurospermum maritimum out of 46 tested, and in two plants of Stellaria media out of 29 tested in 2001. Such tests were repeated in 2002, and ZYMV was detected in three plants of T. maritimum out of 45 tested, in three plants of S. media out of 52, and in two plants of Trifolium repens out of 17 tested. The virus was successfully transmitted from T. maritimum, S. media and T. repens to indicator plants of Cucurbita pepo convar. giromontiina. Back-transmission of ZYMV was proved by ELISA, electron microscopy and symptoms. T. maritimum was found to be a new natural host of ZYMV.

The consumption of food contaminated with moulds (microscopic filamentous fungi) and their toxic metabolites results in the development of food-borne mycotoxicosis. The spores of moulds are ubiquitously spread in the environment and can be detected everywhere. In this study, the presence of various moulds was determined in pork and beef used as a raw material, in salami emulsions, as well as in five kinds of fermented raw meat products. Penicillium sp., Acremonium sp., Mucor sp., Cladosporium sp., and Aspergillus sp. were the most frequently isolated genera of moulds. Flavourings added to meat during the production of fermented raw meat products were heavily contaminated with moulds. The widest spectrum and the highest counts of microscopic filamentous fungi were observed in the following spices: milled black pepper, nutmeg, garlic powder and crushed caraway. The level of contamination depended upon the season, being higher in the summer months.

Relationship between initial oospore number of Pythium oligandrum, mode of the mycoparasite application and populationdynamics of Fusarium oxysporum f.sp. dianthi and development of Fusarium wilt of carnation was studied. Mixing ofoospores with peat 10 days before carnation planting resulted in strong inhibition of the pathogen development. Numberof colony forming units of the pathogen decreased at least 3 times. Application of P. oligandrum resulted in suppressionof Fusarium wilt development, especially when the mycoparasite was applied at dose 100 oospore/g of peat.

The development and ultrastructure feature of secondary hyphae of Podosphaera leucotricha were studied using light and electron microscopy. The percentage of development and length of secondary hyphae, differed in compatible and incompatible combinations. In compatible host-parasite combinations, hyphal cells of powdery mildew fungus contained a full complement of fungal organelles. There were differences of hyphal ultrastructure in compatible and incompatible host-parasite combinations, the main one was the appearance of dense material inside the nucleus, in the cytoplasm, and a few mitochondria.