Udder secretion samples from mastitic and healthy udders were examined at the Department of Veterinary Medicine of the LUA Research Centre "Sigra". In total, 117 samples from 117 cows were investigated. Somatic cell count was recorded for cows with clinical and subclinical infections, and uninfected cows. The mean somatic cell counts for cows with clinical and subclinical mastitis were 1 825 250+-417 697 cells ml*[-1) and 967 866+-75 796 cells ml*[-1), respectively. For healthy cows the mean somatic cell count was 87 666+-15 384 cells ml*[-1). Gram-positive microorganisms from the genera Micrococcus, Staphylococcus, Streptococcus, and Corynebacterium, and gram-negative microorganisms from the genera Enterobacter, Klebsiella, Salmonella, Escheria and Pseudomonas were isolated from samples from mastitic quarters.

The forest certification becomes actual within the forest sector as a trade restriction when customers have started to require products from certified sources. There are several international documents that are regulating the use of international market restrictions. However some misunderstandings and problems with interpretation of free market and forest certification regarding certified product market still exist.

During the period 1995-1998, in the western part of Lithuania, the organic and intensive (conventional) cropping systems were compared on small autonomous drainage plots in limed Bathihypogleyi-Albic Luvisols (LVa-gld-w) and Dystri-Endohypogleyic Cambisols (CMg-n-w-dy) as well as non-acid Endocalcari-Endohypogleyic Cambisols (CMa-n-w-can) soils. This paper presents the summarised results of field crop productivity and the factors determining drainage water runoff as well as the migration and balance of elements in the organic and intensive cropping systems.

One of the most serious diseases of the potato crop worldwide is late blight caused by Phytophthora infestans (Mont.) de Bary. Most growers control the disease by applying fungicides at regular intervals of 8-10 days from the time of row closing until the end of the growing season. The NEGFRY model is used for timing the chemical control of potato late blight. The NEGFRY model is based on two existing models, the "negative prognosis", for forecasting the risk of primary attacks, and a model for timing subsequent fungicide applications during the season. The main objective of NEGFRY is to get high yield and quality with minimum use of fungicides. Present work underlies the experiments that were arranged in 2000 and 2001 at the Jogeva Plant Breeding Institute. Two potato varieties with different resistance to late blight were taken to the experiment in both years: susceptible 'Adora' and modarately resistant 'Anti' in the year 2000 and susceptible 'Berber' and 'Anti' in 2001. NEGFRY gave highest economical effect among six tested treatment regimes.

Evaluation of virulences of Blumeria graminis f.sp. hordei was started in Latvia in 1981, first in the Baltic States. Until 1994 the observations were carried out only in the central part of Latvia - Salaspils. As the climatic factors and the used barley varieties in various parts of Latvia are different, in 1995 we started regular observations of the particularities of the genetic structure of the pathogen population also in Daugavpils. The aim of this investigation was to detect particularities of the genetic structure of the pathogen population in different parts of Latvia in 1996-2000.

The author of this publication offers to analyse and appraise development problems of a pupil's personality in pedagogical environment. This ensures respect for the holistic principle in scientific investigation. Pupil's qualities of personality, its structure and advance, dynamics of development, in the author's opinion, are necessary to be investigated not only in different separate spheres of their activity and manifestation, but in a unity determined by the holistic principle in pedagogy. The development of a personality takes place through interaction with the environment. The aim of the publication is to present a characteristic of interaction between a pupil's personality and rural school as a pedagogical environment in the context of topicality, contradictions, tendencies and problems in today's education.

Agriculture more than any other branch of production is influenced by various natural, anthropogenic and economic risk factors on which the profitability of production and preservation of the environment in rural areas depend. The prerequisite of prevention or alleviation of risks is their all-round knowledge and consideration. In order to understand the nature of risks, they will be dealt with in the present study on the example of the cultivation of the most common cereal in Estonia - barley. The difference in barley yields, resulting from the pedoclimatic coditions of Estonia, may be 2-4-fold in different regions and in different years. At the same time, differences in the profitability of barley cultivation, depending on economic factors and on the specificity of production, may be up to 6-fold.

The goal of this study was to investigate the use of body reserves, energy balance and fertility parameters at the beginning of lactation in first-parity cows bred in Estonia.