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Results 5371 to 5400 of 5716:

Cultivation of Brassica pekinensis under different forms of nitrogen nutrition

L. Ducsay, L. Varga

Hort. Sci. (Prague), 2003, 30(3):112-115 | DOI: 10.17221/3871-HORTSCI

A pot trial was aimed to investigate the effect of different forms of nitrogen fertilizer on the aboveground phytomass yield, vitamin C content and uptake of some macroelements by Brassica pekinensis. The trial was conducted in 2000 and 2001 in pots containing 10 kg of loamy brown soil. Optimized NPK nutrition with the rate of 90.9 kg/ha N increased phytomass yields of Chinese cabbage in all treatments compared to the unfertilized control. The most marked increase (by 55.6%) of yield was obtained when N was applied in the form of (NH4)2 SO4. The yields in the other treatments declined as follows: NH4NO3 > Mg (NO3)2 > KNO3 > DAM-390. Positive effects of full NPK nutrition on vitamin C content were determined. Depending on the forms of N fertilizer, the content of vitamin C in fresh mass of cabbage decreased in the following order: DAM-390 (629.0 mg/kg of fresh mass) >Mg(NO3)2 > KNO3 > NH4NO3 > (NH4)2SO4. Optimization of NPK rates contributed to the increase in N, P, K, Ca, Mg and S uptake by the yield of final product in comparison with unfertilized control. The highest uptake of nutrients was determined in the treatment with N applied in the form of (NH4)2SO4.

Study of biochemical variability of potato cultivars by soluble protein, isoesterase, and isoperoxidase electrophoretic patterns

J. Bárta, V. Čurn, J. Diviš

Plant Soil Environ., 2003, 49(5):230-236 | DOI: 10.17221/4118-PSE

Biochemical variability between thirteen European and five Czech potato (Solanum tuberosum L.) cultivars grown in theCzechRepublic was studied by soluble protein, isoesterase, and isoperoxidase electrophoretic patterns. It was confirmed that cultivar differences in protein polymorphism can be revealed by applied electrophoretic patterns. It was shown that the different character of protein and isozyme profiles required different approaches to their evaluation. For complex patterns such as electrophoretic soluble protein spectra, it is more convenient to use the evaluation of their absorbance profiles and for simpler profiles of isozymes the evaluation based on the presence or absence of a band in a definite position (simple matching) should be used. In spite of the complexity of tetraploid disposition of analysed cultivars, the results suggested higher similarity of profiles between relative cultivars and they also indicated the existence of higher similarity between cultivars from the same breeding firm.

Morphometry analysis and seed germination of Amaranthus cruentus, A. retroflexus and their hybrid (A. × turicensis)

V. Lanta, P. Havránek, V. Ondřej

Plant Soil Environ., 2003, 49(8):364-369 | DOI: 10.17221/4138-PSE

A morphometric study of Amaranthus cruentus, A. retroflexus and their hybrid, A. × turicensis based on 75 plant samples (750 inflorescences), collected throughout the Olomouc-Holice area (Czech Republic), is presented. Using multivariete methods (including cluster analysis and canonical discriminant analysis), the existence of three groupings of plants was proven. The hybrid exhibited intermediate values of the width and length of female tepals, length of awl-shaped bracts, and seed size when compared with parental species. A germination experiment showed that dark seeds of A. × turicensis as well as dark seeds of A. retroflexus germinate scarcely and independently on the day length while light seeds of A. cruentus germinate promptly and markedly better under a short day regime. The chromosome analysis showed that A. retroflexus, A. cruentus, and A. × turicensis have the same chromosome number 34.

Chances and factors of economical farming

J. Homolka

Agric. Econ. - Czech, 2003, 49(5):239-241 | DOI: 10.17221/5398-AGRICECON

The contribution is focused on an analysis of the existing forms of farming in Czech agriculture which are characterised by an economical way of farming on agricultural land. Forms, an extent and economic connection of these farming ways are included. Above all, it deals with the programs of extensive use of land in worse natural conditions, principles of organic agriculture, farming in areas with a special water regime and so on. These ways of farming have to be a part of the state agrarian policy and the connected financial participation of the state in their supporting.

The intensity and quality of Internet usage in the agriculture sector and possibilities of its further development - Information

J. Jarolímek, J. Vaněk

Plant Soil Environ., 2003, 49(11):525-529 | DOI: 10.17221/4188-PSE

The level of the usage of information and communication technologies (ICT) has a direct influence on the development and competitiveness of individuals, firms, production sectors, regions and even the whole continents. The availability of ICT, including the Internet, to agricultural enterprises in theCzechRepublicis already very satisfactory. Due to the structure of agricultural enterprises the penetration of Internet technologies in theCzechRepublicis more intensive than in most EU countries. Therefore an urgent issue is the level of the usage of these technologies that is not an issue related to finances anymore but it is a problem related to the knowledge and habits of users and availability of information and services. The project of the portal for the agriculture sector and countryside AGRIS has a significant impact on the level of the usage of Internet information and services in the agriculture sector.

Economic software - information support of product cost management

A. Látečková, E. Škorecová

Agric. Econ. - Czech, 2003, 49(8):365-368 | DOI: 10.17221/5415-AGRICECON

Adequate product cost economic management is not possible at present without economic software application. Based on the analysis of the current state of enterprise information systems in agriculture, we define basic methods of automatic processing of economic trials and this on the enterprise management level and in-plant level. For product cost management enhancement, we recommend managerial information system application, which introduces extension of enterprise information system and allow real time cost analyse with multidimensional disintegration. We also introduce requirements that economic software suitable for information management needs should ensure.

Precocious beginning of blossoming and tree decline in apricot cultivar Bergeron

Z. Vachún

Hort. Sci. (Prague), 2003, 30(2):59-66 | DOI: 10.17221/3816-HORTSCI

Tree mortality was recorded in a selection orchard of maintenance breeding of cv. Bergeron LE-2 in 1993-2002. The beginning of blossoming was examined in individual trees in the same orchard in 1999-2002. Considering the effect of year, a maximum difference in the average beginning of blossoming was 10 days in the whole set of trees. The beginning of blossoming of individual trees was not identical in the same year. A difference in the onset of phenophase "beginning of blossoming" between early and late blossoming trees was 1-4 days in the particular years. The trees maintained their early or late blossoming for the whole period of evaluation. No tree died in the orchard by 1998. From 1999 to 2002 50% of early blossoming trees died and only 2.38% of late blossoming ones (average of three replications). Two thirds of early blossoming trees died during vegetation, a third died during vegetation rest. No commercially important viroses were proved to be present. It is the reason why viruses could not be a potential cause of the above-mentioned facts. The presence of phytoplasm (ESFY) was confirmed by the method NESTED PCR in one case in a randomly selected early blossoming tree. The test was negative in two randomly selected late blossoming trees from underplanting. The early beginning of blossoming did not influence productivity. Correlations between the beginning of tree blossoming and blossom abundance, or between the beginning of blossoming and productivity, were insignificant (r = 0.12 or r = -0.13). Even though the causative agent of higher mortality in early blossoming trees was not confirmed unambiguously, it is desirable to select the best individuals only from the group of late blossoming ones during maintenance breeding of cv. Bergeron. These individuals should be used as prebasic material in a certification process and as basic material after prescribed repeated testing.

Effect of desiccation on the root system of Norway spruce (Picea abies [L.] Karst.) seedlings and a possibility of using hydrogel STOCKOSORB® for its protection

M. Sarvaš

J. For. Sci., 2003, 49(11):531-536 | DOI: 10.17221/4796-JFS

The aims of this study were: 1. to determine the effect of dexiccation treatment on the physiological quality of Norway spruce (Picea abies [L.] Karst.) seedlings by measurements of electrolyte leakage from the root system; b) to test the use of hydrogl STOCKOSORB® for protection of the root system of spruce seedlings during their transplanting. The results showed that desiccation treatment significantly affected the rate of electrolyte leakage (34% leakage for control seedlings and 53% in contrast with seedlings after 5 hours of desiccation). Likewise, significant differences were found in height and root collar increments after the first vegetation period that decreased with the duration of desiccation treatment. The values of electrolyte leakage also increased with the duration of desiccation treatment for seedlings treated with hydrogel. On the other hand, the rate of electrolyte leakage was lower after 5 hours of stress factor than in untreated seedlings. The height and root collar increments were higher in seedlings treated with hydrogel for all variants. The obtained results showed a possibility of using the measurement of electrolyte leakage from the root system to determine the physiological quality of Norway spruce seedlings. The rate of electrolyte leakage over 40% signals the physiological damage to the root system of spruce seedlings. Next, the results confirmed the need of protection of seedling roots during handling. The seedlings without hydrogel had 35% height and 26% root collar diameter increment after two-hour desiccation stress. On the other hand, the same seedlings with STOCKOSORB had 42% height and 48% root collar increment.

As, Cd, Pb and Zn uptake by Salix spp. clones grown in soils enriched by high loads of these elements

M. Vysloužilová, P. Tlustoš, J. Száková, D. Pavlíková

Plant Soil Environ., 2003, 49(5):191-196 | DOI: 10.17221/4112-PSE

As, Cd, Pb and Zn accumulation in the aboveground biomass of seven clones of Salix spp. and changes in element uptake by plants after element addition to soil were studied in a pot experiment. Unpolluted Chernozem (Suchdol) as a control and soils with addition of As (100 mg/kg), Cd (40 mg/kg) and either Pb (2000 mg/kg) (Suchdol-Pb) or Zn (2000 mg/kg) (Suchdol-Zn) were used for the experiment. Significant differences were found in the accumulation of elements between willow clones and also between different element additions to the soil. Although As and Cd uptake slightly increased in Suchdol-Zn soil compared to Suchdol-Pb soil, the element removal from soil was significantly higher in Suchdol-Pb soil due to a significant reduction of aboveground biomass yield in Suchdol-Zn soil caused by Zn phytotoxicity. The yield reduction decreased the uptake of plant-available elements by biomass, thus higher plant-available portions of As and Cd were found in Suchdol-Zn soil. Element removal from soil was more dependent on element contents in willow tissues in Suchdol-Pb soil than in Suchdol-Zn soil, where willow plants exhibited physiological symptoms of phytotoxicity.

Policy analysis for globalized agriculture

S. Offutt

Agric. Econ. - Czech, 2003, 49(2):67-70 | DOI: 10.17221/5267-AGRICECON

Farms, farmers, farm families, and even farm policies have changed in the United States and Europe over the decades since World War II. Now it is time to bring the methods of farm policy analysis and the scope of data collection up to date. Agricultural economics, by tradition an empirical discipline, can offer important insights into the design, implementation, and effectiveness of policy. To succeed in this century, though, requires an emphasis on understanding micro-economic behavior at the level of the farm household. The paper presents fundamental aspects on methodology for micro-level farm policy analysis and data requirements for application of its intruments.

Changes in the composition of cell wall proteins in barley roots during germination and growth in aluminium presence

L. Tamás, M. Šimonovičová, J. Huttová, I. Mistrík

Plant Soil Environ., 2003, 49(7):327-331 | DOI: 10.17221/4132-PSE

Root growth inhibition and loss of cell viability in barley root cells were induced by Al during germination of barley caryopses on filter paper moistened with 2mM AlCl3. The inhibition of root growth as well as loss of cell viability started on the third day of germination. This time was also needed for induction of Al-induced changes in the composition of cell wall proteins. The accumulation of three salt-extractable polypeptides with relative molecular mass 14, 27, and 29 kDa started 72 h after the beginning of germination of barley caryopses on Al containing filter paper. However, the inhibition of developmentally regulated deposition of three (18, 23 and 28 kDa) salt-extractable CW polypeptides was observed at the same time. The pattern of detergent-extractable CW proteins was not influenced by Al regardless of the duration of Al treatment.

Development of structure and exploitation of agriculture land fund in Latvia

V. Mičurová

Agric. Econ. - Czech, 2003, 49(4):179-183 | DOI: 10.17221/5376-AGRICECON

Agriculture is a sector in Latvia which plays an important role in the country's economy and the same time performs a significant social, environmental and ethno-cultural function. Latvia has favourable conditions for the development of organic agriculture. The aim of land reform is to reorganise legal, social and economic relationships of land property and land use to facilitate the development of infrastructure, land protection and rational land use according to the interests of society. In Latvia, the land reform is practically carried out in three directions - restitution of real estate rights, privatisation of real property and compensation for previous real estate. At the moment, the main and urgent goal concerns strengthening of the results of land reform. It means that all the information on real estates (land and buildings), uses and area of lease obtained during the previous course of land reform must be reflected into the real property cadastre.

To-and-fro migration of rural population

L. Kříž

Agric. Econ. - Czech, 2003, 49(7):329-333 | DOI: 10.17221/5406-AGRICECON

Integrated projects of rural microregions: Experiences in the Central Bohemia region

V. Mlejnecká, L. Kříž

Agric. Econ. - Czech, 2003, 49(12):557-563 | DOI: 10.17221/5448-AGRICECON

The article brings the empiric reflection and results-based analysis of the "Programme of Rural Revival" realization in the territory of the Central Bohemia Region (NUTS II/III) in the time of regional self-governing organization in the Czech Republic. The primary interest of the authors was focused on the participation of microregions in the Programme activities, resp. on the item and object spectrum. The scope of the grant title 7 of the " Programme of Rural Revival" is assigned specifically for microregions. The successful request-analysis indicates varying spheres of activity and themes that microregions prefer in their demands for the Programme subsidy. It is, among others, observed through the interest for preparation of projects in the LEADER+ programme intention because the grant title 7 is also available for the LEADER+ preparation purposes. The preferences of microregions reflected in the requests indicate a further trend of territory-development supported activities. Unsuccessful requests analysis points towards broad relations of the Programme realization at the institutional-legislative level. Further evaluation concerned the fundamental Programme aims and their fulfilment presents the failure of agricultural undertaking in the grant requests. As the paper concludes, the authors suggest partial recommendations, in their opinion, for improving the "Programme of Rural Revival" application in the Central Bohemia Region.

Biological and chemical amelioration effects on the localities degraded by bulldozer site preparation in the Ore Mts. - Czech Republic

V.V. Podrázský, J. Remeš, I. Ulbrichová

J. For. Sci., 2003, 49(4):141-147 | DOI: 10.17221/4689-JFS

Biological and chemical (fertilising, liming) amelioration are among the principal tools used to restore degraded sites. These techniques were also used on the Ore Mts. plateau on plots prepared by bulldozing. We evaluated the impact of these amelioration techniques by measuring tree species primary production and humus form restoration. Begun in 1983-1985, this project studied growth reaction of forest stands by measuring height and diameter increment, for the following species (blue spruce Picea pungens Engelm., European larch Larix decidua Mill., lodgepole pine Pinus contorta Dougl., Eastern white pine Pinus strobus L., alder Alnus incana Moench., European beech Fagus sylvatica L.) during the period 1994-2000. The growth potential by species decreases in the following order: larch, alder, lodgepole pine, white pine, blue spruce. Beech was almost exterminated by red deer browsing and the harsh climate; pines suffered heavily from browsing and bark stripping. Holorganic horizons were measured and basic soil chemical and mechanical characteristics were determined - pH, soil adsorption complex characteristics (using Kappen's methodology), content of the humus and total nitrogen, exchangeable acidity and plant available macronutrients, granulometric composition of mineral soil horizons. Our results confirmed the relatively long-lasting effects of soil amendments, as well as the amelioration effects of alder, and the relatively inhibiting effects of larch and blue spruce.

Analysis of cambial activity and formation of wood in Quercus robur L. under conditions of a floodplain forest

P. Horáček, J. Šlezingerová, L. Gandelová

J. For. Sci., 2003, 49(9):412-418 | DOI: 10.17221/4714-JFS

The analyses of the activity of cambium and the study of the increment of wood during one growing season of pedunculate oak (Quercus robur L.) under conditions of a floodplain forest is provided. The following parameters were studied: the beginning and end of the cambial activity, differentiation of wood fibres (libriform) and vessels and analysis of the total increment of wood during vegetation in dominant (D), co-dominant (CD) and subdominant (SD) trees in relation to ecological factors of the environment. The course of wood formation corresponds to typical growth curves which are modified by factors of the environment (mean daily temperature, precipitation, soil water supply). The rate of growth is limited by factors of the environment and under the lack of some of them it is reduced resulting in the decrease in the total production of cells. Oak is a species sensitively responding to the period of drought which is particularly manifested in wood increment in subdominant trees. Sufficient supplies of water during spring months accelerate the formation of early wood including differentiation of spring vessels as corroborated by the results. The total formation of wood is dependent not only on the characteristics of the respective growing season but particularly on the social position of trees in the stand.

Fast prediction of quality parameters in whole seeds of oilseed rape (Brassica napus L.)

V. Míka, P. Tillmann, R. Koprna, P. Nerušil, V. Kučera

Plant Soil Environ., 2003, 49(4):141-145 | DOI: 10.17221/4104-PSE

A calibration equation for NIRSystems 6500 instrument was derived at VSTE Jevíčko using the measurement of broad collection of Czech samples of winter rape, allowing sufficiently accurate prediction of content of dry matter (DM), crude protein (XP), crude fat (XL), glucosinolates (GSL), oleic and linoleic acids in an extremely short time. The prediction accuracy was verified on a validation file (n = 60). The coefficients of determinance (R2) were 0.83 for XP, 0.71 for XL, and 0.84 for GSL. The prediction accuracy according to the VSTE equation was compared to the prediction accuracy according to the VDLUFA calibration equation (Kassel, FRG) used in EU near infrared spectroscopy network. It was stated that the former was not distinctly worse. Non-destructive NIR-analysis of the whole seed also allows sowing selected seeds in the year of harvest and thus accelerates the breeding cycle.

Comparison of the value added development in the agricultural and food sectors and the efficiency of its creation

M. Ševčíková

Agric. Econ. - Czech, 2003, 49(1):22-29 | DOI: 10.17221/5260-AGRICECON

The article summarises the results of the analysis of value added (VA) in agriculture and food industry and the share of intermediate consumption in the value added. The results show that during 1993-2000, the Slovak agricultural sector (farming, hunting, forestry and fisheries), where farming is clearly dominant, together with the construction sector, reported the most significant decline in their relative contribution to the overall value added created in the national economy, whereas the contribution of market services increased. The moderate increase (1998, 1999) in the contribution of the food sector to the total value added in the national economy, as well as to industrial production (2000), has been brought to a halt and, eventually, began deflating. The tendency of declining participation of the agricultural sector in value added was also typical for the EU member states and for the CEFTA countries. Agriculture remains dominant in terms of its contribution to value added in the agri-food sector (54.5% in the year 2000). In the category of land-farming holdings, the share of intermediate consumption in value added increased (both in co-operatives and business companies, whether loss-making or profitable). The farmers in mountainous areas spent per 1 SKK of value added 0.65-1.42 SKK more of intermediate consumption than farmers in the maize production area and 0.54-1.32 SKK more than farmers in the sugar-beet production area. In the production of foodstuffs, beverages and tobacco processing, which is more demanding in terms of consumed inputs than agricultural production (the same is true for developed economies), the ratio between intermediate consumption and value added differed depending on the branch concerned. Agriculture was one of the most demanding sectors in terms of fixed asset investments necessary to generate value added. The initial decline was brought to stop in 1998 and the relative share of fixed assets (FA) in value added (VA) started to increase, particularly in the year 2000, mainly under the influence of increased support to farmers' capital investments. Although the creation of value added in agricultural co-operatives initially demanded more investments in fixed assets than it was the case in farming business companies, the difference narrowed over the time. The group of loss-making entities reported the FA/VA ratios twice as high as the group of profitable entities, which sends a signal to the former to revise the structure of their production and to improve management practices. Similarly as in the case of intermediate consumption, also the FA/VA ratio increased as the production conditions deteriorated. The ratios in the production of foodstuffs and beverages (without tobacco processing) were significantly lower than those in the farming sector. In 1999, the lowest FA/VA ratio occurred in the production of durable bakery products and the highest in the production of fruit and vegetable juices.

Slovak agriculture heading for the EU membership

G. Blaas

Agric. Econ. - Czech, 2003, 49(3):120-127 | DOI: 10.17221/5275-AGRICECON

The paper analyses the economic and policy gap between the agriculture in Slovakia and the EU member states from the perspective of the future accession of this country to the Union. As it concludes, the deterioration of terms of trade during the transition period creates also problems for the accession negotiations, because this fact seems to legitimate the equitable implementation of the CAP in all member countries after the East-enlargement of the Union. The paper is arguing, on the basis of income simulation, that that the Commission proposal on reduced direct payments for the newly admitted countries would, in case of Slovakia, generate an improvement of the sectoral income only if they are topped by rural development measures.

The effect of plant population densities on growth, yield and yield components of two spring rapeseed cultivars

H. Ozer

Plant Soil Environ., 2003, 49(9):422-426 | DOI: 10.17221/4151-PSE

Rapeseed (Brassica napus L.) is an important alternate oilseed crop in eastern Anatolia, Turkey. No information on plant density for rapeseed is available in this region. Therefore a study was initiated to investigate the effects of spacings between rows and spacings within rows on the yield and agronomic characteristics of two genotypes of spring rapeseed (Tower and Lirawell) in Erzurum, eastern Anatolia, during 1994 and 1995. The effects of spacings between or within rows on the yield and yield components of Tower and Lirawell, two cultivars of Brassica napus L., were studied for 2 years inErzurum,Turkey. Rows were spaced at 15, 30 and45 cm. Spacings within rows were 5, 10 and15 cm. The results of this study suggested that seed yield was significantly affected by spacings between rows but not by spacings within rows, and that rape yields were higher at the narrow (15 cm) row spacing compared to the middle (30 cm) and wider (45 cm) spacings.

The effect of feeding technologies on the economics of fattening pigs

M. Šprysl, R. Stupka

Agric. Econ. - Czech, 2003, 49(6):284-289 | DOI: 10.17221/5388-AGRICECON

The aim of the experiment in test station was to evaluate productive performance with respect to feeding-technologies through the test for LWs × (LW×L) genotype in pigs. The productive performance as growth capacity, feeding intake and quantitative traits of slaughter value was examined for 144 hybrid pigs divided in two identical groups, where the 1st group was fed ad-libitum and the 2nd one semi-ad-libitum. On the base of profit formula, the ad-libitum system of feeding in pigs is better in all economic features.

Economic evaluation of cattle management in the system of organic farming

I. Živělová, J. Jánský, P. Novák

Agric. Econ. - Czech, 2003, 49(10):469-475 | DOI: 10.17221/5434-AGRICECON

This paper introduces partial results of the research project QC 1140 aimed at the efficiency of enterprises operating in the system of organic farming, especially considering the use of grassland linked with cattle management. Economic evaluation of cattle management in the system of organic farming is compared with conventional enterprises. Economic evaluation applies to dairy cattle and beef cattle. Proposals of the measures will be formed with respect to the results of analysys, which should contribute to the support of organic enterprises and to better satisfaction of the increasing demand for organic food.

Economic analysis of forest joint-stock companies in the Czech Republic in 1992-2000

V. Kupčák

J. For. Sci., 2003, 49(1):27-36 | DOI: 10.17221/4675-JFS

The basic principle of the economic reform of state forests of the CzechRepublic after 1990 was to separate ma­nagement in forests from the implementation of production activities. A state enterprise Forests of the Czech Republic with its headquarters in Hradec Králové was charged to manage state forests. From the former 7 enterprises of state forests 78 joint-stock companies have been established that carry out silvicultural and logging activities in state forests and in forests of other owners under the conditions of competition environment and on the basis of contracts. The paper deals with the exact evaluation of partial and present results of the development of forestry economic reform, aimed at the study of the behaviour of transformed and privatised forest joint-stock companies.

Effect of fertilisation on Norway spruce needles

V.V. Podrázský, S. Vacek, I. Ulbrichová

J. For. Sci., 2003, 49(7):321-326 | DOI: 10.17221/4706-JFS

Yellowing of Norway spruce is a relatively common problem in many regions of the Czech Republic. At some places, it is also connected with forest decline. This unfavourable phenomenon is initiated by several ecological as well as anthropogenic processes. One of the most important is the imbalance of forest stand nutrition. Particular reasons lead to nutrient deficiency, especially deficiency of magnesium. Solution to this undesirable trend is a profound ecological analysis and cause-oriented treatments. Besides decreasing air pollution impacts, fertilisation with deficient nutrients represents a successful treatment in the forest stand management in affected areas. In the area of interest, application of relatively small amounts of appropriate fertiliser (SILVAMIX Mg) led to considerable improvement in the defoliation dynamics and yellowing progress since the first year after application.

Research of sugar-beet tubers mechanical properties

J. Skalický

Res. Agr. Eng., 2003, 49(3):80-84 | DOI: 10.17221/4956-RAE

Approach to the problems of sugar-beet tubers surface damage dependence on harvesting technology. Investigation of sugar-beet tubers damage when falling on wood and iron surfaces and in the next case tuber damage caused by their fall on the tuber heap. Research of damage rate dependence on the fall height. Evaluation of damage rate was carried by the I.I.R.B. method (method used by all sugar-beet growing countries of Western Europe). The results refer that no considerable differences in damage rate after the fall on the wood or iron bottoms have been ascertained. The height of 1.5 m can be considered in all cases as the limit value of the tubers fall, when share of heavily damaged tubers reached acceptable values of 10-15%, but that the share increases significantly at higher falling height. The lifting bodies construction requires also a knowledge of dependence between root depth and force for tuber release from soil in relation to the tuber weight. Medium force needed for tubers lifting ranges from 17 to 27 kp, maximum value 50 kp was found out for tubers of weight above 3 kg.

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).

Adaptation of Blumeria graminis f.sp. hordei to barley resistance genes in the Czech Republic in 1971-2000

A. Dreiseitl

Plant Soil Environ., 2003, 49(6):241-248 | DOI: 10.17221/4120-PSE

Results of scoring the resistance of 35 selected spring barley varieties to powdery mildew, exhibiting high powdery mildew severity, in 307 variety trials of the Central Institute for Supervising and Testing in Agriculture were analysed. The varieties can be divided into two groups: the varieties that could not induce any changes in the pathogen population (the varieties with no effective resistance gene and varieties carrying gene mlo) and the varieties possessing major resistance genes [a total of 12 Ml-genes: a1, a3, a6, a7, a9, a12, a13, at, k1, La, g and (Kr)] to which the pathogen population adapted in 1971-2000. The time slope of decreasing resistance of varieties is described. The importance of individual evolutionary forces (mutations, migration, direct selection, indirect selection and recombinations) for the erosion of efficiency of respective major resistance genes and the effects of pathogen adaptation on population complexity and diversity are discussed.

Economic efficiency of agricultural enterprises in the system of organic farming

J. Jánský, I. Živělová, P. Novák

Agric. Econ. - Czech, 2003, 49(5):242-246 | DOI: 10.17221/5399-AGRICECON

The aim of this presentation is to introduce partial results of this research project aimed to the efficiency of businesses working with the organic systems. The proposal of mesures will be formed with the respect of results of analysis to support organic businesses, to increase organic land area corresponding with the progress in the EU and therefore to help to satisfy increasing demand for organic food, last but not least also to prove, that organic agriculture is truly functioning part of multifunctional agriculture.

Potassium dynamics in the soil and yield formation in a long-term field experiment

H.W. Scherer, H.E. Goldbach, J. Clemens

Plant Soil Environ., 2003, 49(12):531-535 | DOI: 10.17221/4189-PSE

The influence of an interrupted K fertilisation on different K fractions of the soil, yield formation and K uptake by different crops was investigated in a long-term field experiment on Luvisol derived from loess. Irrespective of the previous K fertilisation, the interruption of K fertilisation resulted in a sharp decline of CAL extractable K. K concentration in the saturation extract as well as HCl extractable K were reduced while K fixation capacity increased within 10 years after omitting K. Omitting K fertilisation decreased yields of sugar beet and potatoes while cereals were not affected, although K uptake of all crops reacted to the differentiated K supply to a different extent.

The state and development of financial structure in agricultural co-operatives

Ž. Hacherová, R. Hulík, I. Pribilovičová

Agric. Econ. - Czech, 2003, 49(8):369-374 | DOI: 10.17221/5416-AGRICECON

The main idea of the paper is to evaluate the state and development of financial structure of selected agricultural co-operatives in accounting periods from 1994 till 2001. Assets financial stability constitutes an ability of an enterprise to create and balance an accurate relation between assets and their financial sources. The results of the research work document a positive tendency in financial structure in favour of equity capital (Table 1). On the other hand, there have been problems with borrowed capital mainly with the liabilities from business relation. An increasing level of earnings can be assessed positively as well as the participation of new loans in the financial basis of enterprises (Table 3).

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