Fulltext search in archive

The paper is a part of solution of the research plan of the FBE MUAF in Brno, No. GAMSM 431100007, and it is focused on analysis of factors influencing intensity of competition fight among the existing firms in the Czech dairy industry - describing their actual situation and their possible development in the future relating to the expected integration of the Czech Republic into the European Union. All analysed factors are important and significantly intensify competition fight among the existing firms in the industry. The level of concentration is low - 16% of businesses in the industry control 60% of market, but almost 30% of businesses in the industry have only 3% share in the market, growth of the industry is slow - about 5% annually, and barriers of exit from the industry are significant. Situation of the next four factors (level of fixed and storage costs, product differentiation and switching costs, size of capacity augmentation, diversity of competitors) is similar.

Relations between the level of milk yield and the economic results of dairy cows breeding were analysed on the base of operational and economic data received from 135 agricultural enterprises. The analysis was aiming at the optimization of milk production expressed by means of the cost function. By evaluating the above-mentioned relations, there was recorded a tendency of the faster growth of milk yield compared to the costs for market milk for one feeding day of a dairy cow. On the base of the expense function, there was expressed the maximum profit for a litre of market milk, the maximum profit for a dairy cow per year and the interval of profitability of milk production in 2000.

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.

An analysis is made of the root system morphogenesis and architecture in several tens of European mountain ash trees aged up to 60 years at seven different sites. Although the root system variability is considerable, certain dependences can be derived. European mountain ash forms an anchoring root system. Limiting factors of the root system morphogenesis are the groundwater table (roots do not penetrate into soil horizons affected by underground water), prevailing direction of wind (elliptic root system develops in the wind direction), and the slope (in the uphill direction the roots are shorter, exhibit the more or less horizontal growth and reach into deeper soil horizons than roots growing in the downhill direction). An unambiguous correlation was found between the rooting depth of anchor roots and the number and reach of lateral roots (the longer the anchors, the fewer the lateral roots and the smaller their reach). The shorter the anchor roots, the more intensive the branching of not only the anchors themselves but also of superficial roots.

In the period 1996-1999 field trial was performed in Obory near Kwidzyn on heavy textured Fluvisols. The experiment was aimed to determine yield, chemical composition, heat value of wood of six genotypes of willow coppice in relation to cutting frequency and on determining the costs and profitability of willow production on arable land for purposes of energy generation. Yield of wood dry matter in one-year cutting cycle amounted to 14.09 t/ha/year 1 and significantly increased to 16.05 and 21.55 t/ha/year when harvesting was performed in two and three years cycle, respectively. The highest yield was found for Salix viminalis 082 form cut in three years cycle and it amounted to 26.44 t/ha/year 1. Stems of Salix sp. cut every three years showed the lowest water content (46.05%), high heat value 19.56 MJ/kg dry matter and the highest content of cellulose (55.94%), lignins (13.79%) and hemicelluloses (13.96%). High yielding potential of Salix sp. and high content of cellulose and lignin in wood make this crop very prosperous as a feedstock for bioenergy production. The highest profit from the willow plantation was obtained in case of harvest every three years at 578.76 EUR/ha/year.

A translocation from Aegilops ventricosa carrying genes Yr17, Lr37 and Sr38 was verified in cultivars Hussar, Eureka, Torfrida, Renan, Rendezvous, Rapier and Brigadier by the molecular marker SCARSC-Y15. Of the cultivars recently registered in the Czech Republic, only the western European cultivars Corsaire, Apache, Complet and Bill possessed the translocation carrying Yr17, Lr37 and Sr38. Cultivars Corsaire, Apache, Bill and Complet were highly or medium resistant to yellow rust and leaf rust in 1999-2001 field trials at Prague-Ruzyně, although virulence to Yr17 was found in the 2001 virulence survey also in the Czech Republic. Cultivars Corsaire, Apache and Bill displayed an above average resistance to stem rust, whereas Complet was susceptible.

It is well established that race-specific resistance selects for the specifically matching genes effecting virulence in the pathogen. As well, the use of different R-genes in time makes virulence complexity, VC (the number of virulences per pathogen genotype), to increase. Moreover, it becomes obvious here that the wind-dispersed cereal rusts and mildews are obligate nomads and highly mobile. As a consequence of these points and as a result of modelling, VC was expected to increase in the direction of predominant winds, e.g. from west to east across Europe, and it did by approximately one or more virulences per 1000 km. Starting from the barley mildew pathogen, comprehensive evidence is also available from leaf rust on wheat covering some 5000 km from Western Europe into Siberia. The impact of our findings for population genetics across Europe and Asia is supposed to be considerable and worth further elucidating, e.g., within the 6^th EU Framework Programme.

The pure cultures of the fungus Leptosphaeria maculans were isolated from the rapeseed leaves collected in Moravia. Two isolates were collected on the basis of their ability to produce yellow colour. The isolate producing yellow colour was classified as aggressive, while the isolate without the ability to produce yellow colour was not aggressive. The sensitivity to these isolates was verified in 11 rapeseed genotypes. This test was based on the method from the document Crucifer Genetics Cooperative (information document from the Department of Plant Pathology, University of Wisconsin). This method is based on the inoculation of cruciferous leaflets with suspension from the isolate of the pathogen observed. The scale from 0 to 9 was used for evaluation (0 = no darkening around the wound, 9 = accompanied by profuse sporulation in large, more than 5 mm, lesions with diffuse margins). The infection degree of the aggressive isolate ranged in different genotypes from 1.45 to 4.5, the results of the non-aggressive isolate ranged from 1.0 to 1.5. Based on these results the aggressive isolate was used for further tests of the selected breeding lines. The tests involved selected breeding materials, registered varieties, control varieties with different sensitivity to the isolate of Leptosphaeria maculans and control varieties included in state trials. The maximal difference in the sensitivity exhibited by individual genotypes was five degrees.

The effectiveness of fenarimol and difeconazole, DMIs fungicides, and dodine was tested in two experimental orchards and in greenhouse in two seasons. In 2001 monitoring of resistance to dodine was conducted also in some commercial orchards located in main apple production. In both experimental orchards fenarimol gave significantly poorer control of apple scab than difenoconazole when curative treatments were applied. The same results were obtained in greenhouse tests using for inoculation the suspension of conidia of V. inaequalis from these orchards. In many monitored orchards, in each region, a high level of dodine resistant isolates in population of V. inaequalis (even more than 40%) was noted. Only in six from 65 tested orchards there was less than 1% resistant isolates in population of the fungus.

Method ISTA SDS-PAGE was used for separation, detection and evaluation of high molecular weight glutenin subunits (HMW) in the different wheat species. The relation has been studied between the HMW glutenin subunit alleles and the bread-making quality of 25 world wheat cultivars and 21 regional varieties common wheat varieties (Triticum aestivum L.), 17 winter spelt wheat (Triticum spelta L.), 3 durum wheat cultivars (Triticum durum DESF.), 9 cultivars of Triticum turgidum L. and 5 cultivars of Triticum polonicum L. The highest frequency of occurrence of HMW glutenin subunits 2*, 13 + 16 and 5 + 10 were found in world wheat cultivars. In Slovak wheat varieties were analysed subunits 0, 7 + 9 and 5 + 10, 2 + 12. The HMW subunits 0, 7 + 8 with Glu-score 4 were determined in Triticum durum DESF. Three electrophoretical profile groups of different HMW glutenin subunits were found in Triticum turgidum L. and Triticum polonicum L. and six electrophoretical profile groups were determined in Triticum spelta L. The verified correlations between bread-making quality and specific HMW subunits of glutenin can be utilised by wheat breeders using SDS-PAGE of proteins as a screening test for the prediction of bread-making quality of wheat.

Field trials were conducted at two sites Troubsko near Brno and Prague-Ruzyně in 1996-1999 with three varieties of safflower (Gila, CW-74, Sironaria). Three rates of nitrogen fertilization were used: N0 = no fertilization, N₁ = 40 kg/ha, N₂ = 80 kg/ha. Sowing rates were 50 and 70 germinable seeds per m2. The average values of oil content were highest in seeds of CW-74 variety (27.2%). Gila had on average the lowest oil content (24.5%). Linoleic acid was dominant in all three safflower varieties. Variation in content of linoleic acid in different years was not so high as in oil content. The highest average content of linoleic acid was found in Gila variety (81.2%), the lowest in Sironaria (77.4%). At Ruzyně average seed yield on dry basis was 2.7 t/ha and average straw yield was 7.56 t/ha. At Troubsko seed yield was 2.56 t/ha and straw yield was 3.69 t/ha (by 50% lower than at Ruzyně). The effect of year of growing and site on seed yields and on other parameters was highly significant. N fertilization increased safflower seed yield at Troubsko site only, where the dose of 40 kg/ha N increased the yield by 0.08 t/ha on average of years and the dose of 80 kg/ha N increased the seed yield by 0.2 t/ha in comparison with no nitrogen fertilization treatments. Increased N rates and especially higher plant density resulted in an increase in straw yields. Neither were thousand seed weight nor number of flower heads influenced significantly by different N rates or the above-mentioned differences in plant density.

There are 80% municipalities under one thousand inhabitants in the CzechRepublic. The population trend observed in the region ofSouth Bohemia has proved a long-term and gradated depopulation of such small municipalities. While population has fallen in municipalities under one thousand inhabitants, towns and municipalities with more than one thousand inhabitants show the opposite trend. The possibility of changing this trend seems to lay in the state help for small municipalities parallel with the expected change of the situation after the EU accession because it is very probable, that many young families will be looking for the financially more convenient living in the country.

Due to the transformation of the agricultural subjects realized after 1990, the new ownership relations occurred in the sectors of agriculture and food processing. The entrepreneurs started to build their activities on the base of market economy principles. The farmers started founding of specialized or universal-trading organizations aimed to sale of the agricultural production. The legal forms of the companies were cooperatives or companies incorporated. In practice, the subjects proved the reasonability of their existence not only on the side of agricultural production sale, but also on the side of purchasing inputs necessary for the agricultural production process. One of the best trading organizations is Agropork-družstvo in Brno, which is specialized in purchasing and sale of pigs, cows and recently poultry as well.

The complex solution of farming in worse natural conditions and exploitation of land fund result from the successive transformation of agricultural policy and the preparation of agrarian sector for the accession of Slovakia into the European Union. The character of this policy will have the immediate impact on economy mainly of enterprises farming in less-favoured areas (LFA). In the study, we present the actual data about the allocation of agricultural land and agricultural farms into the LFA using the database of information system on land and the soil quality database which is managed by the Research Institute of Agricultural and Food Economics.

Changes in fruit weight, firmness and soluble solids content during the ripening period of Karešova cv. Including relationships between these characteristics were studied in 1998-2001. These years differed from each other in the amount and distribution of rainfall and in the course of temperatures. The length of ripening period fluctuated from 14 to 21 days. An increase in average fruit weight during the ripening period was 0.1 g per day. The actual increase in fruit weight was in a close correlation with the amount of rainfall in a few previous days. After heavy rainfalls, above 40 mm, fruit weight increased by nearly 1 g within in a few days. In the course of the ripening period fruit firmness decreased from about 2.5 N at the beginning of the period to about 1.5 N at its end. This decrease seems to be mainly the function of time during ripening. However, a low correlation between the amount of rainfall in the previous days and the decrease in firmness was also found. This correlation could be connected with negative regression of fruit firmness on the weight of the fruit. In the more rainy years 1998 and 1999 these decreases in firmness were more significant than in the other two years. Soluble solids content (SSC) increased from about 12% Brix at the beginning of the period to about 16% at its end. There were also found positive correlations between the weight of fruits and SSC. Taking into account contributions of all studied factors and their changes a conclusion was drawn that Karešova cv. should be harvested within one week from the beginning of its ripening period.

In three investigated stands the highest increment (8.8 m3/ha per year, i.e. 1.5% of the actual stand volume, measured at the end of the control period) was reached by Jawornik I stand in the initial period of the growing up stage, and Tworylczyk stand in the advanced growing up stage (7.4 m3/ha per year, i.e. 1.2% of the actual stand volume). Jawornik II stand, in the optimum stage, the aging phase, had the lowest increment (3.9 m3/ha per year, i.e. 0.7% of the actual stand volume). The process of a natural volume loss was the most intensive in Tworylczyk stand (7.6 m3/ha per year), a little less intensive in Jawornik II stand (7.1 m3/ha per year), and the least intensive in Jawornik I stand (5.8 m3/ ha per year). The analysis of tree loss, recruitment, and increment, and the relations between these processes, can form the basis for a conclusion that stable stands developed in the Carpathian primeval beech forests in the years 1988-1998. Such steady processes can be used for the development of a stable, multifunctional model of the forest managed by the selection system, or the Swiss irregular shelterwood system in the Carpathian beech stands of a similar structure.

The laboratory incubation with glucose treatment was carried out in order to estimate the possible effects of increased microbial activity on heavy metal availability. The soils from vicinity of a lead smelter operating for more than 200 years were used for the experiment. The DTPA-extractable heavy metal contents increased after glucose addition and mostly reached the highest values the second day of the incubation. The comparative study, where the chloroform fumigation was used prior to the incubation in order to decrease the microbial activities, showed especially from second day of incubation significantly lower DTPA-extractable metal contents compared to non-fumigated treatments. The interactions among the maximum possible availability of DTPA-extractable heavy metal fractions and native soil microbial characteristics were studied in differently contaminated arable and grassland soils. Irrespective of different heavy metal contents in soils, significant correlations were found among the maximum percentage increase of DTPA-extractable Pb and Cd and the ratio Bc/TOC and metabolic quotient (qCO₂) which may be a result of the important role of organic matter and microbial characteristics in soils on the heavy metal availability.

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.

Arabidopsis is universally resistant as a species to many crop pathogens, including examples from other crucifers suchas Albugo candida and Hyaloperonospora parasitica from Brassica oleracea. This species level trait could potentiallyprovide a source of durable disease resistance in crops if examples can be found which are amenable to molecular geneticcharacterization. Our research has developed from the observation that null mutation in Arabidopsis of a defense regulatorygene EDS1 (enhanced disease susceptibility) is susceptible to isolates of A. candida and H. parasitica from brassica.EDS1 is required by a major structural class of R-genes to confer resistance in Arabidopsis. We have therefore focusedon identifying R-genes in Arabidopsis that are responsible for conferring resistance to brassica pathogens.

Peach latent mosaic viroid (PLMVd) is widespread in peach all over the world. It has never been reported from the Czech Republic. That is why we adapted specific and sensitive method for its detection, PCR, to be able to prove its possible occurrence and for certification purposes. Primers PLMVdR, PLMVdF1 and PLMVdF2 were designed on the basis of published RNA sequences. Products of amplification are 208 and 114 bp long for PLMVdF1 and PLMVdF2, respectively. Four PLMVd isolates from Dr Di Serio (CNR Bari) were used as standards. Potato spindle tuber viroid and Hop latent viroid infected plant material and also healthy material were used to check detection specifity. Both RNA extraction from plant material and PCR were optimalized so that this method of PLMVd detection can also be used for certification purposes.

From 2000 to 2001 the population dynamics of Psammotettix alienus Dahlb. were recorded using a sweep-net or a biocoenometer. The investigations were carried out in Zscherben near Halle (Middle German Dry Region). The imagines of the first generation of P. alienus could be observed for the first time at the beginning of May (2000) and at the end of May (2001), respectively. According to our results, in this area three generations of P. alienus are developed. In both years of our observations the barley-strain of Wheat dwarf virus (WDV) occurred. The main important infections appeared in autumn. Furthermore, during the whole period of our investigations the percentage of viruliferous individuals which were caught was recorded by means of a biological test. In June this percentage achieved 84.0% (2000) and 76.7% (2001), respectively. In the course of summer months of both years the percentage of viruliferous P. alienus decreased. In autumn of the year 2000 an increasing portion followed once again. However, in the year 2001 a continual reduction from > 70% in June to < 5% in late autumn could be observed.

As tobacco black shank epidemics caused by Phytophthora nicotianae occurred in central Italy in the late 1990s, fungal antagonists of the pathogen were searched in the rhizosphere of tobacco plants. Isolates of Aspergillus sydowii, Fusarium chlamydosporum, Gliocladium roseum, Penicillium brevicompactum, P. chrysogenum, Scopulariopsis candida and Trichoderma harzianum were recovered. Antagonism of these isolates toward P. nicotianae was evaluated in vitro: even if no hyphal interactions were observed in dual cultures, aberration in mycelial growth and morphology of sporangia occurred in most cases. Unlike those of T. harzianum, concentrated culture filtrates of A. sydowii, F. chlamydosporum, G. roseum, P. brevicompactum, P. chrysogenum, inhibited growth of all P. nicotianae isolates tested, while culture filtrates of S. candida caused aberrant mycelial growth.

The main goal of this work was to calibrate and evaluate the CERES-Barley and CERES-Wheat crop models. The experimental fields used for the model evaluation are situated in three different production regions (maize, sugar beet and potato main growing regions, respectively) with altitudes of 179, 204 and 560 meters above the sea level. Grain yield and date of anthesis together with maturity dates served as reference for the model evaluation. Two evaluation approaches were tested in this study. The first one uses historical data series and it is based on long-term field experiments with capability to reflect interannual weather variability. The second approach uses results of one-year multiple treatment experiment. The model evaluation is then based on a set of treatments differing e.g. in sowing date or an amount of used nitrogen fertilizer. Grain yields simulated by both models are acceptable when compared with experimental results: the coefficient of determination for historical series varied from 0.69 to 0.86 for evaluation of CERES-Barley at the three examined sites and reached values of 0.60 and 0.86 for the CERES-Wheat model at two experimental sites. The lower coefficient of determination of the wheat model was recorded at the locality with the highest altitude and coldest winter conditions. There, also the worst reliability of simulated phenological development was noted. At the second locality where the CERES-Wheat model was tested and at all three localities where CERES-Barley was applied, the simulated duration of vegetation period and anthesis dates were relatively accurate and yielded strong statistical correlation. The one-year multiple treatment experiment proved to be useful to determine the models sensitivity to differences in crop management. The combination of both approaches seems to be the best solution for evaluation of similar crop models if the detail long term experimental data are not available.

A model experiment was conducted to compare hand extraction (elutriation) under running water and elutriation using the device Analysette 3, the two methods for estimation of weed seedbank in the soil. Technical parameters have been assessed for efficient operating of the device. We studied the time required for elutriation of soil samples and the time for collecting, counting and identifying the separated seeds. No significant difference in the effect of the used elutriation method on results of qualitative and quantitative estimation of weed seedbank densities has been found at any of the three locations differing in soil texture (silty loam, loam and clay loam soil). The time necessary for elutriation of soil samples was highly significantly shorter if the device was used, by 35.5 to 42.9% depending on soil texture vs. hand elutriation. The shortest time was assessed for silty loam soil. By contrast, the time needed for selecting, counting and identifying seeds was shortest for clay loam soil. This time was 46 and 92% longer for loam and silty loam soil, respectively. These differences were statistically highly significant. Comparing the seedbank in the soil, a significantly lower number of weed seeds as well as species was found on silty loam soil vs. the two locations with heavier soils. Amaranthus retroflexus was a dominating species at all locations, and on silty loam soil also Chenopodium album. Of a total number of 32 weed species detected in our experiment, 28 were annual and only four perennial (Cirsium arvense, Elytrigia repens, Rumex obtusifolius and Sonchus arvensis).

Internal and external entropy are indicators of evaluation of the success of the firm management. The evaluation of the file of the chosen agricultural firms shows, that the level of internal and external entropy is not too high for the future dynamics and development. Competitiveness of the evaluated firms can be influenced especially by problematic level of their interior social situation (it means social subsystem measured with the help of the internal entropy) that is connected with a not very efficient management of the human resources.

Even ten years after the revolution in 1989, Slovak agriculture is characterized by the predominant position of cooperatives. There were shifts towards other types of agricultural entrepreneurship, and some of these trends we documented in our article, based on the data gained by surveying agricultural enterprises. We drew a conclusion that cooperatives are more labor demanding. This also means that they still preserve a social role as a main employer in rural areas. Our paper also differentiates between Southern and Northern (less favorable for agriculture) regions, represented by the Nitra and Žilina region, respectively. We examined soil quality, labor intensity, wages, and finally main crops yields in these two regions.

The author deals with the influence of cost taxes on the development of agriculture, mainly those taxes, which have an important impact from the point of view of forming an entrepreneurial environment in agriculture. Among the cost taxes, the impact of land tax, building tax, road tax and income tax is most important. The analysis also deals with the contribution to the insurance funds related to employees. This contribution can also be considered as a taxation. The article also gives a prediction of the expected development of the consequences of the accepted tax law changes.

Forty two peach-nectarine (Prunus persica [L.] Batsch.) varieties (i.e Spring Time, Precocissima Morettini, Southhaven, Halehaven, Blazing Gold, Cardinal, Gialla Precoce Morettini, Dixired, Fertilia Morettini, Golden Jubilee, Coronet, Red Haven, Red Globe, Cotonia Massima, Morettini 5/14, Peach of Station, Alexander, Early Elberta, Elberta of Middle Season, Beauty of Georgia, J.H. Hale, Late Elberta, Gold Drest, Morettini No. 1, Jerseyland, Desert Gold, Red Cup, Spring Crest, Loring, June Gold, Merril Gem Free, Early Red, Red Skin, Merril Fortyminer, Roubidoux, Fantasia, Sunhaven, Flavour Top, Merril Franciscan, Blake, Fairtime, Fayette) were studied for 12-18 years in three experimental orchards of Peripheral Agricultural Research Station of Rhodes (PARSR). Their degree of adaptation to the soil and climatic conditions of PARSR was evaluated in terms of yield per tree, time of bloom, time of fruit ripening, fruit quality etc. These results have been compared with related experimental data recorded at the Pomology Institute (PI) at Naoussa. The results indicate that: many peach-nectarine varieties with quite high chilling requirements (Loring, Blake) gave satisfactory yield in PARSR, where the mean average of temperatures below 7°C over one decade was found to be 147 hours (range 52-226). Some peach-nectarine varieties in experimental orchards of PARSR ripened more than ten days earlier (Desert Gold, Early Red, Peach of Station, Loring, Merril Gem Free), of others at about the same time (Coronet, Cotonia Massima, Red Skin, Fertilia Morettini, Red Globe) and at others on a later date (Merril Fortyminer, Early Elberta, J.H. Hale, Cardinal, Southhaven) than they would ripen in northern Greece (PI). Similar differences were also found for the time of blooming.