Fulltext search in archive



« advanced mode »

 previous    ...   40   41   42   43   44   45   46   47   48   49  50    next 

Results 1441 to 1470 of 1498:

The changes of the agribusiness impact on the competitive environment of agricultural enterprises

V. Bečvářová

Agric. Econ. - Czech, 2002, 48(10):449-455 | DOI: 10.17221/5351-AGRICECON

The market extension generally affects growth performance positively by allowing an expansion of markets, by increasing outside competition as well as by more rapid diffusion of new products, processes and research output between national economies. The positive effects of considerable market on productivity are indubitable. However, two other weighty phenomena of the process are necessary to investigate, effects of regulatory policy and market power exhibits. Agriculture as a sector belongs to those, where the support policies exist for a long time. Nevertheless, the last decades have witnessed considerable changes in this sector among most of developed countries and their agricultural/regulatory policies. It has been perceived, that the agriculture for 21st century cannot be separated from the other components of agri-food sector. The economic importance of the processing and finalization stages (i.e. food industry and food distribution) has increased over time. There are concerned inter-relationships between the market structures development and the crucial factors of the interconnected markets developments in the framework of production verticals of agricultural commodities. Reflecting the steadily more sophisticated supply side behaviour, solution is based upon the demand oriented approach explaining changes of the position of agriculture within the agri-food chain. Conflict of interest between the regulatory/agricultural policy and the market power of input supply and output processing firms and retail notably has increased dramatically. Economic manifestation of the increasing market power on the demand side as well as the impact of market interrelationships and change of policy regulation efficiency within commodity chains are characterised there. The position of agriculture within the agri-food chain has changed and the influence of farmers has decreased. Success of agricultural enterprises in achieving their operational goals is still more influenced by improvements in productivity and by competitiveness of other "links" of the agri-food chain.

Comparison of different PCR-based protocols for detection of Roundup Ready soybean

J. Ovesná, L. Dedičová, J. Horáček, E. Sadilová, L. Kučera, L. Měsková

Czech J. Genet. Plant Breed., 2002, 38(1):55-63 | DOI: 10.17221/6111-CJGPB

Genetically modified organisms have become a part of our environment and food chain. Roundup Ready soybean is at the moment the most frequent one that man can meet. National regulations require careful monitoring and detection of GMOs. We present in this investigation comparison of several protocols and individual steps, which are included in the whole detection procedure. Currently used CTAB based protocol is suitable for DNA isolation from the green plant tissue but also from the flour. Lectin coding sequence specific primers were suitable for soybean DNA detection unlike leu-tRNA gene specific primers. Only one of the tested CaMV sequence specific primer pairs did not amplify unspecific products under condition tested. NOS terminator specific primer pair was found suitable for routine screening. EPSPS gene was detected using two different protocols; the same primers did not identify other Roundup Ready GM crops.

Incidence of temperature-related abiotic diseases in Spanish garlic bulbs

J. Cabrera, F.J. López-Bellido, D. Recio, J.M. Alía, M. Serrano, C. Verdejo

Plant Protect. Sci., 2002, 38(11):696-699 | DOI: 10.17221/10593-PPS

Several alterations of growth physiology and bulb formation in garlic (Allium sativum L.) crops, such as "rough" and "burst" bulbs, have been related by different authors with low temperatures during bulbs storage and crop development. These physiopathies affect both the yield and the quality of garlic crops. Incidence of such diseases in Spanish garlic (variety "purple of Las Pedroñeras") were studied during two consecutive years. Experimental design was factorial taking the bulb storage temperature (5°, 10°, 15° and 20°C) as variable factor. Growth indexes during crop development and final quantity of defective bulbs were evaluated. Experimental results show significant differences between treatments, with the higher incidence of both physiopathies in those bulbs stored at 5°C. The 15°C and 20°C storage temperatures clearly reduce the risk of these abiotic diseases and tend to increase the yield and the final quality of the crop.

The effect of perennial forage crop on grain yields in submontane regions

J. Šroller, J. Pulkrábek, D. Novák, O. Faměra

Plant Soil Environ., 2002, 48(4):154-158 | DOI: 10.17221/4214-PSE

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).

Multivariate statistical methods as a tool of financial analysis of farm businesses

J. Novák, H. Sůvová, J. Vondráček

Agric. Econ. - Czech, 2002, 48(1):9-12 | DOI: 10.17221/5281-AGRICECON

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.

Introduction

J. Novák, H. Sůvová

Agric. Econ. - Czech, 2002, 48(9):381-382 | DOI: 10.17221/5340-AGRICECON

Natural regeneration at different microclimatic sites in Zatec regionOriginal Paper

I. Kupka

J. For. Sci., 2002, 48(10):441-450 | DOI: 10.17221/11913-JFS

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.

Countryside, tourism development and national heritage revitalisation

T. Hájek

Agric. Econ. - Czech, 2002, 48(6):259-262 | DOI: 10.17221/5314-AGRICECON

The society has deepened its reflection on the future of the Czech countryside - not only in connection with the multi-functional agriculture but mainly with regard to the actor of service. It seems that this reflection went relatively far especially in the tourism industry where an understanding of a need for complex legislation defining the tourism industry as a long-term interest of the whole society (especially in connection with regional development) was reached. Since in the Czech countryside, national heritage monuments constitute both the key attraction and the axis of the inhabitant structure, tertiarization of the countryside cannot take place without strengthening of the revival strategies with regard to the national heritage monuments. However, among the heritage protectors themselves, no reflection in this sense has yet taken place.

Terrain properties of selected forest sites in the Jizerské hory Mts., Czech RepublicOriginal Paper

M. Modrý, V. Simanov

J. For. Sci., 2002, 48(7):310-319 | DOI: 10.17221/11890-JFS

Differentiation of forest technologies according to ecosystem properties is a necessary step to achieve sustainable forestry. A forest typological system is considered to be the basic unit of ecosystem differentiation in the Czech Republic. Terrain characteristics, potential water erosion and applicable harvest technology were examined for 44 forest sites in a landscape segment of the Jizerské hory Mts. Forest site was found homogeneous in terms of terrain and technological properties. Edaphic category and groups of forest types as higher classification units and management sets as units of alternative classification showed lower homogeneity insufficient for operational planning.

Transcript imaging and candidate gene strategy for the characterisation of Prunus/PPV interactionsOriginal Paper

V. Decroocq, V. Schurdi-Levraud, D. Wawrzyńczak, J.P. Eyquard, M. Lansac

Plant Protect. Sci., 2002, 38(10):S112-S116 | DOI: 10.17221/10332-PPS

Plum pox virus (PPV), the causing agent of the sharka disease, belongs to the genus Potyvirus that contains the largest number of virus species infecting plants. The virus genome has been extensively characterised and sequenced. However, few data are available on its interactions with the host plant, Prunus. In this study, we are focusing on the cloning and characterisation of any candidate genes involved in the expression of the resistance/susceptibility trait and any polymorphic genes putatively involved in the trait variation. In order to clone candidate genes, two main approaches are currently developed: the homology cloning of genes presumed to affect the resistance/susceptibility trait and the differential screening of cDNA pools corresponding to infected and non-infected plant material. The second approach is based on the transcript imaging of the host plant response to PPV infection. Previously, it has been shown that infection by a potyvirus is associated with specific changes in host gene expression, mainly down-regulation, while the expression of some genes remained unchanged. Thereby, in the differential display approach combined to further characterisation of candidate gene expression, we aim to monitor host gene expression in response to the virus and to describe a highly regulated interaction between the Prunus host plant and the infecting Plum pox virus.

Approaches to the rural development problems in the European Union and in some of the Central and Eastern European countries

M. Vosejpková

Agric. Econ. - Czech, 2002, 48(4):171-174 | DOI: 10.17221/5299-AGRICECON

Utilisation of regional policy helps to reduce disparities among regions. The approaches to solving these problems in the European Union differ from the approaches practised in Central and Eastern European countries. The development of rural areas in the European Union is realised through the principles of regional policy and its instruments, i.e. Structural Funds, in co-operation with the Common Agricultural Policy. The applied assistance from the Structural Funds is aimed at the objectively defined areas. The situation of countries with many socio-economic problems is reflected in the weak demographic structures of these regions. Solutions of the problematic situation can be found in implementation of the approach supporting the development of multi-functional agriculture and a broader social and territorial context of economic development in all adopted tools of rural development. The way of supporting diversification of the competitive rural economic structure based on encouraging new activities leads also through integrated programmes. Regional policy realisation in the CEECs depends on the institutional framework created in the dependence of the habits applied by the past political regime of the relevant country. The basic issue for the sustainable development of rural areas can be seen in diversification of agricultural activities, creation of small firms and development of tourism together with sustaining the countryside specifics.

The significance of commodity exchanges for trade in agricultural products in the Czech Republic, and prospects of their future development

O. Rejnuš

Agric. Econ. - Czech, 2002, 48(10):467-472 | DOI: 10.17221/5354-AGRICECON

The paper deals with the functioning of commodity exchanges in the Czech Republic, and is particularly concerned with exchanges trading in agricultural production commodities. The introductory part of the paper is oriented towards the theory and general structure of commodity exchanges; the other parts subsequently deal (in more detail) with the most problematic areas of their operation in the Czech Republic up to the present time. Within this part of the paper, the method of analytical evaluation is used for examining, above all, the existing legal regulation, the structure and function of these exchanges. Subsequently, using the method of comparative analysis, selected key aspects of their operation are compared with the theoretical requirements of their functioning as well as with the everyday functioning of this kind of exchange in economically developed countries. Findings gathered this way are subsequently utilized in the concluding part of the paper, the subject matter of which is a prediction about the possible variants of the future development of Czech agricultural commodity exchanges, with regard to the assumed admission of the Czech Republic to the European Union.

Assessment of Frost Tolerance of Wheat Doubled Haploids by Gliadin Electrophoresis

I.T. Prášil, P. Prášilová, A. Šašek, J. Černý

Czech J. Genet. Plant Breed., 2002, 38(3):104-108 | DOI: 10.17221/6243-CJGPB

The relationship between gliadin alleles, known to mark frost tolerance, and actual frost tolerance was investigated in 52 doubled haploids (DH) from the cross Florida× Vlada. Frost tolerance was expressed as percentage of plant winter survival in pots placed at different heights above the ground. Gliadin allelic blocks (GLI) were determined by starch electrophoresis. From the six GLI, known as frost tolerance markers, the GLI 1B1, GLI 1D5 or GLI 6D2 was present in 27, 27 or 31 DH, respectively. A weak, but significant correlation of r = 0.29 was found in the DH between their survival and frost tolerance prediction values based on the presence of the gliadin frost tolerance markers. The average survival of DH with gliadin frost tolerance marker GLI 1B1 or GLI 6D2, but not with GLI 1D5, was significantly higher than the survival of DH without this block. The DH without any gliadin frost tolerance marker had the lowest survival. Some gliadin genes thus can be used as frost tolerance markers for preliminary selection of frost tolerant lines and for the study of physiological and genetic constitution of frost tolerance in common wheat.

Critical values of trace elements in soils from the viewpoint of the transfer pathway soil - plant

E. Podlešáková, J. Němeček, R. Vácha

Plant Soil Environ., 2002, 48(5):193-202 | DOI: 10.17221/4224-PSE

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.

Institutional problems of pig meat sector in the Czech Republic

M. Pourová, M. Pour

Agric. Econ. - Czech, 2002, 48(1):29-35 | DOI: 10.17221/5285-AGRICECON

The paper deals with the institutional problems in the pig meat sector in the Czech Republic. The information was obtained in the frame of Project PHARE-ACE P97-8098-R "Institutional Economics in the Agri-Food Business: How can Structural Policy Help to Integrate EU?" The research was performed in year 2000 by means of a questionnaire method and a method of interviews with managers of individual entities in the food chain of pig meat sector. Problems of the execution of property rights in supplier-customer relations in the Czech pig meat sector are the following (institutional view): poor enforceability of property rights, sale for cash, refraining from long-term contracts, decrease of trust between business partners and trust in legal institutions, increase of transaction costs, lack of business ethics etc.

The evaluation of economic situation and comparison of Czech and French agricultural enterprises

F. Simon, J. Novák

Agric. Econ. - Czech, 2002, 48(9):389-394 | DOI: 10.17221/5342-AGRICECON

The comparison of Czech and French agriculture results shows a higher intensity, productivity and profitability of French agriculture. There are just small differences in the effectiveness of the production. The Czech agricultural enterprises have been in economic distress for several years and only a low portion of them is able to modernize and increase reproduction. There is also highlighted the importance of the EU Common Agricultural Policy for the development and stabilization of French agriculture.

Production weight and its variability in 24 apricot genotypes over six years

Z. Vachůn

Hort. Sci. (Prague), 2002, 29(3):105-113 | DOI: 10.17221/4472-HORTSCI

Productivity and its stability were evaluated in a set of 24 apricot genotypes of the world collection and some promising new selections in 1994-1999. The productivity of most genotypes was higher than that of control variety Velkopavlovická LE-6/2. Genotypes with higher productivity in the years favorable for apricot productivity gave higher yields also in the years unfavorable for productivity. It was proved by a significantly close highly significant correlation (r = 0.64++). It is a reason for the necessary regulation of fruit set in highest-yielding varieties in the years favorable for apricot productivity when overproduction and undesirable reduction in the fruit size occur. The variability of yields in kg per tree, expressed by coefficients of variation over a six-year period, was high in the years of observation. The variability of yields was significantly lower in the years favorable for apricot productivity. To express yield variability the coefficient of variation and index of fluctuation can be used. Their similar conclusiveness was proved by the significant positive closeness of correlation between the values determined by both calculations (r = 0.51+). The varieties Vynoslivyj and Volšebnyj showed the highest and most stable productivity. From the producer's and breeder's aspects, of these two the Vynoslivyj variety is one of the most remarkable genotypes of the evaluated set due to its fruit quality and late ripening.

Soil conditions of black walnut (Juglans nigra L.) stands in the alluvium of the Svratka and Jihlava riversOriginal Paper

M. Hřib, J. Kulhavý, M. Sáňka, J. Lesná

J. For. Sci., 2002, 48(11):486-498 | DOI: 10.17221/11917-JFS

Physical, chemical and microbiological properties of soils were studied in black walnut (Juglans nigra L.) stands and compared with those in stands of natural species composition, in mixed stands of black walnut with linden and in pure oak stands. The objectives were to consider a possibility of black walnut planting at floodplain sites in the alluvial area of Southern Moravia. The first results did not show any worsening of soil properties and soil production potential. A positive amelioration effect of soil- improving species was proved in black walnut stands.

Ways of increasing resistance to viruses into the single plant and in populations

I.T. Balashova-Lakhmatova, N.N. Balashova, V.F. Pivovarov

Plant Protect. Sci., 2002, 38(11):545-551 | DOI: 10.17221/10551-PPS

Viruses as phytopathogenes have been discovered at 1892, and 638 plant's viruses have been identified at 1989. Some of its may be epidemic and to cause significant yield losses of cultivated crops. Increasing resistance of the single plant and populations is the necessary condition for the control of viruses spread and damage. Our proposals for the increasing resistance to viruses: For the single plant the soft correction of plant's metabolism with pretreatment of the natural bioantioxidants and immunizators - steroid glycosides. It results in lowering of virus infectivity, degree of plant's affection and increasing of the yield on 11-41% in fact (in ToMV-tomato pathosystem). For the plant's population- increasing to the necessary proportion the lot of tolerant and resistant forms into the plant's assortment; - selection of resistant and tolerant forms from populations have been selected earlier as resistant to other pathogens and obtaining of the basic material collection with complex resistance; - hybridization programs and developing of tolerant and resistant hybrids; - use molecular markers of resistance for the limitation of virus infection backgrounds in the breeding programs.

A critical appraisal of non conventional resistance to plant virusesReview

G.P. Martelli

Plant Protect. Sci., 2002, 38(10):S15-S20 | DOI: 10.17221/10311-PPS

Among natural resistance mechanisms to plant pathogens, cultivar resistance has been extensively used in plant breeding to introduce what can be defined as "conventional" resistance to a number of them, including viruses. The necessity of overcoming the constraints of genetic incompatibility, so as to widen the range of possibile use of genetic control of infectious agents, has propitiated the utilization of biotechnological procedures, whereby "non conventional" or transgenic resistance was developed. Transgenic resistance to plant viruses encompasses the identification, cloning and tranferring into the recipient host of single viral genes, which gives rise to what is known as "pathogen-derived resistance" (PDR). Of the hypothesized mechanisms underlying expression of PDR, post-transcriptional gene silencing has been most extensively investigated in recent years. Despite of the success that virus-resistant cropping of transgenic plants begins to enjoy, in Europe there is still a widespread sentiment against agricultural biotechnologies and the use of genetically modified plants in particular. Yet, experimental evidence is accumulating that, in the case of PDR, the feared risks associated with genetic trasformation are minimal, if not negligible

Nutrition economics - important source of information

J. Hrubý

Agric. Econ. - Czech, 2002, 48(4):183-188 | DOI: 10.17221/5301-AGRICECON

Intellectual capital and talents in agribusiness organisation development

M. Horalíková, P. Berglová

Agric. Econ. - Czech, 2002, 48(11):505-510 | DOI: 10.17221/5361-AGRICECON

Human resources are a key factor in the development and competitiveness of organisations. The concept of organisation's intellectual capital enables a complex and systematic look at the decisive organisation sources (including human resources). Talents - people with management skills and the so-called project talents play an important role within the frame of human resources. Talents - bearers of special endowments and abilities - are a decisive factor in the growth of the organisation. Partial probes carried out in agribusiness organisations have confirmed the significance of both theoretical concepts. At the same time, they have revealed that organisations utilise various kinds of talents the differentiation of which requires a more profound examination and analysis in order to assess, in a competent way, the contents and forms of education of young professionals, as well as the contents and forms of lifelong education in the field of agribusiness.

Stephen H. Howell - Molecular Genetics of Plant Development

K. Pánková

Czech J. Genet. Plant Breed., 2002, 38(3):135-136 | DOI: 10.17221/6250-CJGPB

Occurrence and harmful effects of Gymnosporangium sabinae (Dicks.) Winter in Slovak Republc

Gabriela Juhásová, Ján Praslička

Plant Protect. Sci., 2002, 38(3):89-93 | DOI: 10.17221/4856-PPS

The fungus Gymnosporangium sabinae (Dicks.) Winter was found only at three locations during the years 1965 to 1990 in Slovakia, they were the Arboretum at Mlyňany, Topoľčianky and Gbely (JUHÁSOVÁ 1973, 1975, 1998). We noticed a more frequent occurrence of this fungus during recent years. The life cycle, range of woody host plants and degree of damage on pear leaves at selected locations inSlovakia are described.

Molecular and genetic studies of the basis of virulence/avirulence in Meloidogyne chitwoodi

V.C. Blok, J. Wishart, D. Mugniéry, M. Bossis, P. Castagnone-Sereno, C. Neveu, G. Smant, C. Zijlstra, F.C. Zoon, M.S. Phillips

Plant Protect. Sci., 2002, 38(11):714-716 | DOI: 10.17221/10597-PPS

Within the EU project DREAM there is a programme of work investigating the molecular basis of virulence and avirulence in Meloidogyne chitwoodi and which involves partners from the Netherlands, France and Scotland. In Wageningen AFLPs are being used to examine genetic diversity between populations of M. chitwoodi. Partners in Wageningen and INRA are using M. javanica and M. incognita as model systems to isolate genes producing secreted proteins that could be implicated in the host pathogen interaction. They will search for homologous sequences in M. chitwoodi. At Rennes two-dimensional electrophoresis (2DE) studies are being conducted. The PCR based suppressive subtractive hybridisation (SSH), has been used at PRI and SCRI to compare avirulent and virulent nematodes and infected plant material (resistant and susceptible) at different times after infection.

The effect of nitrogen fertilization, sowing rates and site on yields and yield components of selected varieties of safflower (Carthamus tinctorius L.)

Z. Strašil, Z. Vorlíček

Plant Soil Environ., 2002, 48(7):307-311 | DOI: 10.17221/4368-PSE

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.

Differentiation and reasons of decline of agricultural enterprises in Slovakia

Z. Chrastinová

Agric. Econ. - Czech, 2002, 48(9):407-411 | DOI: 10.17221/5345-AGRICECON

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.

Specific productivity of selected apricot genorypes

Z. Vachůn

Hort. Sci. (Prague), 2002, 29(4):125-132 | DOI: 10.17221/4475-HORTSCI

Specific productivity and some correlations between growth and productivity were evaluated in a set of 24 apricot (Prunus armeniaca L.) genotypes in 1994-1999. Even though the planting stock came from the same nursery, was of even age and on the same rootstock, the tree size of genotypes varied from planting to a permanent site. Differences in the tree size of genotypes slightly diminished over the six-year period, likely under the influence of uniform pruning used for all trees. Nevertheless, tree size evaluated from the area of stem cross-section can be considered as a genotype disposition. It is proved by a positive, highly significant correlation (r = 0.84++) between the rank genotypes according to the area of stem cross-section in the fourth and eleventh year after planting. Confidence intervals also confirmed significance of differences in specific productivity. In total, specific productivity of twelve genotypes was significantly higher than in the control cultivar Velkopavlovická. A negative, significant moderate correlation (r = -0.40+) was calculated between tree size and specific productivity expressed as yield weight per unit area of stem cross-section. Weakly growing genotypes had higher specific productivity. The highest specific productivity was recorded in cultivars Vynoslivyj and Priusadebnyj and in LE-1321 and LE-390 hybrids. Of them, the most interesting for producers and fruit quality was Vynoslivyj with average fruit weight 47 g and harvest ripeness 11 days after Velkopavlovická.

In vitro evaluation of fungal antagonists of Phytophthora nicotianae

R. Nicoletti, F. Raimo, E. Cozzolino

Plant Protect. Sci., 2002, 38(11):634-637 | DOI: 10.17221/10577-PPS

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.

Crop response to the application of special natural amendments based on zeolite tuff

A. Butorac, T. Filipan, F. Bašić, J. Butorac, M. Mesić, I. Kisić

Plant Soil Environ., 2002, 48(3):118-124 | DOI: 10.17221/4210-PSE

The conception of these investigations is based on the premise that a way should be found to eliminate, or at least mitigate, the harmful effect of excessive soil acidity without resorting to the massive and costly measures of liming. The main issue addressed in this study is how to increase crop yield by increasing nutrient availability rather than how to neutralize the soil. This as well as our earlier investigations, conducted on pseudogley of mesoelevations, indicate that this can be achieved by the application of special natural amendments (SNA) based on zeolite tuff, under the name Agrarvital (AV), in which clinoptilolite prevails while the remaining part is a mixture of soft lithothamnian limestone and dolomite (SLL+D). These amendments enhance ion exchange in the soil and their activation at a considerably lower pH than it is the case after liming. Fertilizing value of Agrarvital (AV) and lime materials (LM) was evaluated according to the yields achieved and some yield components of the crops grown. The results point to the good fertilizing effect of AV upon yields of winter wheat, maize, soybean and winter barley, equal to or better than the effect of conventional LM applied at several times higher rates.

 previous    ...   40   41   42   43   44   45   46   47   48   49  50    next