Field trials were carried out on organic farming fields at the Research Institute of Agriculture of the Latvia University of Agriculture (LLU). The influence of harrowing (without harrowing, before emergence, at the stage of tillering, before emergence and at the stage of tillering) depending of pre-crop (red clover, winter rye for grain, bare fallow and green manure) and use of stable manure (60 t haE-1 or without) on the weediness and yield of spring barley 'Sencis' was tested during 2003-2004. In spring barley, 18 species of weeds were established at the stage of earing during 2003-2004. The most widespread of perennial weeds were Elytrigia repens (L.) Nevski and Sonchus arvense L. The dominant annual weeds were Chenopodium album L., Stellaria media L., Capsella bursa-pastoris L., Polygonum spp., and Matricaria inodorum L. The number of annual weeds at the stage of earing differed during the years 50-160 (in 2003) and 33-118 (in 2004) annual weeds per mE-2. The influence of harrowing on the number of annual weeds was different during the testing years. The influence of harrowing on the grain yield was negligible during 2003 and 2004.

The article discusses investigations in a flat rectangular contact area of two elastic solids (brake friction lining and disc) using a theoretical method. The solids are in free as well as in forced movement. The investigations have resulted in correlations describing deformation and stiffness parameters of solid flat joint in different loads: transference of the centre of cross section delta0 the angle of turning phi of one solid in relation to the other (as a result of friction lining deformation), and tension sigmax in any cross section of the contact area. The results of the investigations make it possible to analyze the stiffness of the contact of solids, test the strength of the contact areas, optimize the contact are of solids, and prognosticate even wear out of friction lining.

Systainable energy systems and food security can be obtained in rural areas by usage of renewable energy resources and development of agro-ecotechnologies. Substitution of fossil feedstock for energy and raw materials by biomass is important measure also for greenhouse gas (GHG) emission mitigation. The article presents investigation of reed biomass size reduction processes flattening and cutting. The necessity to reduce the size of common reeds (Phragmites australis) to particles smaller than 3 mm for solid biofuel production is determined by compaction properties of biomass. It was stated that unflattened reed stem cutting energy consumption is 2 times more than flattened stem cutting energy. There are no sufficient differences in the energy consumption values for single flattened reed stalk cutting with different shaped knives. The average difference is approximately 2.4 kJ square m with knife edge angles 90 deg and 20 deg.

The studies were made on the surface water and groundwater sources, the existing and future water production yields of the Riga city. The forecasts about water demand in Riga by year 2010 are estimated as 200 000 m**3 dE-1, with a variation coefficient of 1.13. Total water yield is estimated as 410 000 m**3 dE-1, with a storage coefficient of 2.05, which is considered as sufficient. It is proposed that in future 50% of drinking water for Riga will be abstracted from groundwater and 50% will be produced in the Daugava surface treatment plant.

Latvia has become a fully-fledged Member State of the European Union (EU) and now is a part of the global integration processes. The EU has set a goal to form a knowledge-based society and to become a region with a dynamic economy. For this reason it is necessary to increase scientific research and innovation capacity. The scientific potential is characterized by adequate supply of materials, facilities and equipment. It is a precondition for any kind of productive scientific activity. It must be noted that equipment, along with materials and resources necessary for their maintenance and operation in scientific institutes and by groups of scientists, has not experience any significant improvement since the Soviet period. Since 1990, budgetary funding for science has been sufficient to ensure a mere survival. In 2004, Ministry of Education and Science, together with scientific institutions, drafted the National Programme "Support for Modernization of the Scientific Infrastructure in the State Research Institutions". The funding made available through the EU Structural Funds can be used for purchasing new scientific equipment for the state research institutions.

The aim of the paper is to analyze relationship between international trade and the correlation of the business cycles between Baltic countries and their main trading partners. Two univariate methods are used to extract cyclical components in the time series: exponential smoothing procedure the Hodrick-Prescott filter and unobserved components method. A simple regression model proves the hypothesis that trade intensity has led to business cycle synchronization. The main conclusion is that there exists a strong correlation between the business cycles of the Baltic countries. However, the economic cycle of Baltic countries is different from that of their main trading partners in EU. According to Optimum Currency Area theory, these results cast doubts on the usefulness of adopting the euro in the Baltic countries in the near future. On the other hand, recently the deepening of economic integration has led to make intense trade between the Baltic countries and the EU, which may eventually imply more synchronised cycles in the future.

The changes taking place in economics, its internationalisation, development of information and progress of science and technique determine the necessity to raise the country's economic competitiveness, as the result of it the level of life will rise. It is relevant for Latvia to be aware of its advantages and potential competitiveness in order to carry out appropriate macroeconomic policy and favour the introduction of appropriate macroeconomic as well as social policy. The main advantage for providing more rapid development is the fact that Latvia is a small country, able to adopt flexibly, the demand of economic environment where it is easier to achieve a compromise with society. As well as the fact that it is characteristic for the population of Latvia to have a constant tendency towards better life. The way in which Latvia will be able to use its comparative advantages in context of EU market will determine the progress of the national economy including agriculture. At the moment, several problems, which are to be solved, have already appeared in agriculture. The more rapid introduction of technologies of information communication (ICT) in agriculture could be one of the ways to solve the problem. It would provide the development for both economic and social spheres motivating exchange of information, expanding of the market, increasing of production quality, improving work organisation in enterprises, and providing more possibilities for education. To carry out the questioning of students of the Latvia University of Agriculture in the course of study in order to find out the level of ICT application among students, as well as to obtain information about ICT application in the process of education.

Accumulation of skatole levels in porcine fat tissue is a major reason for boar taint, an objectionable odour in meat from entire male pigs. In contrast to males, female pigs do not accumulate skatole in increased amounts. Hepatic metabolism is critical for the regulation of skatole. Cytochromes P4502E1 (CYP2E1) and P4502A6 (CYP2A6) are key enzymes involved in skatole metabolism. The objectives of this study were to evaluate the effects of gender and hCG stimulation on the activities of CYP2A6. Liver samples were taken at slaughter and analyzed for skatole concentrations, and for activities of CYP2E1 and CYP2A6. It was found that female pigs expressed higher CYP2E1 activity whereas activity of CYP2A6 did not differ between sexes. Skatole levels in the liver were higher in male pigs than in female pigs. Neither skatole levels nor enzyme activities were affected by hCG stimulation. It was concluded that the incidence of boar taint may depend on both the amount of skatole reaching the liver, and the activities of enzymes involved in skatole metabolism.

Natural defence mechanisms of the mammary gland tissues play a vital role in protecting the gland from infections. The progress of mammary infection depends on the ability of bacterial pathogens to adapt to milk and udder tissues, and on the various virulence factors they activate, as well as on the cow's response. The levels of immunoglobulins (lg) and lactoferrin (Lf) concentration in the milk from dairy cows with and without subclinical mastitis were determined. In this investigation it was stated that 82.5% of samples were negative, but 17.5% of samples were positive for pathogens. Cows had subclinical mastitis caused by Coagulase negative staphylococci observed in 48.60%, Streptococcus uberis - 32.10%, Staphylococcus aureus - 18.90% of cases in milk samples. There were no significant differences between all classes of immunoglobulins concentration in the milk without pathogens and with pathogens. The lactoferrin concentration was significantly increased for 40.33% in the milk with pathogens.

Due to large diversity of site conditions suitable for Scots pine growth in Latvia, it is important to evaluate their influence on growth and survival of particular Scots pine families. To do so, open pollinated progenies from phenotypically selected plus trees of 35 at the age of 32 years have been evaluated in 2 forest types (Cladinosa-callunosa and Hylocomyosa). Investigation revealed that forest type and family influence had a great significance to height, diameter at breast height, and diameter of thickest branch up to 2 meters' height (alpha is less than 0.001), but clone influence had lower significance (alpha=0.008). Proportion of influence to height growth caused by tree family was 70% at the age of 6 years and 17% at the age of 32 years. Proportion of influence on survival caused by tree family was 57% and 44% respectively. The corresponding influence of forest type was 12% and 28% to height, 15% and 39% to survival. Diameter at breast height at the age of 32 years was equally influenced by forest type and family (~11%). Equal breeding effect - but not with the same families - can be reached both in fertile and poor soils. In group (20%) selection this effect was ~8% for height, 11% for diameter, and 30% for survival; in individual selection ~10% for height, and ~17% for diameter.