The demand for healthy and reasonably cheap food is growing and governments are expanding policies to preserve soil fertility and nature. In addition, climatic conditions are changing. Arable lands are decreasing. Due to all of these changes food growers are looking for new growing technologies. A monographic method to tackle these problems has been used in this article. Intercropping is one of growing systems how to reduce negative climatic aspects and meet other demands. Intercrop is convenient for growers who grow plants in rows, and a companion plant can be sown or planted between rows. In this case farmers can get two yields from one plot. Thus, growers do not need two plots for growing different plants. The intercrop diminishes spreading of pests and diseases, suppresses weed growth, and reduces need for pesticides. Legume (Leguminosae) intercrop gives extra nitrogen to companion plants. Those are aspects that we know intercrop can give, but we do not know how significant the influence is, what kind of influence on nature intercrops give in long term, what kind of influence they have on incomes, yield and its quality. This article shows that there are many intercropping systems to reduce some negative aspects and increase beneficial ones. Intercropping can reduce some pests and diseases, but promote other problems. Intercropping suppresses weeds. For some systems it gives bigger yield, for some smaller, but in total it gives bigger protein yield. There are still many unanswered questions and completely unexplained points.

European pear scab (Venturia pyrina Aderh.) is common and economically important disease in commercial orchards in most of the pear (Pyrus communis L.) growing areas worldwide. Studies on pear scab pathogen V. pyrina diversity in general and among different geographical regions are scars at an early stage. In the limited number of studies reported so far, some attempts have been made to characterize and define races or biotypes of V. pyrina and new biotypes co-adapteted to specific cultivars have been recorded recently. Despite the long history, worldwide distribution and increasing economic significance of the European pear scab, the research on control methods, and pathogen biology and disease epidemiology that could aid to develop more effective and also alternative to fungicide application control methods are still limited. Mechanisms of European pear resistance to scab remains uncertain and currently only one major resistance gene Rvp1 has been identified and characterised. Although the disease is important in many European countries, breeding programs of pear scab-resistant varieties are still under development. In this paper we provide an overview on V. pyrina, its significance and distribution, control methods and current scientific progress in understanding of the pathogen and the disease. Overview of literature on V. pyrina characterization, ecology, biology and diseases epidemiology from Latvia and other countries has been used for the study.

The number of grape (Vitis sp.) cultivars is increasing every year, the focus point of recent grapevine studies are heading to producing high quality fruits for producing quality wine. A field trial with cultivar ‘Zilga’ was established in 2007 at the Estonian University of Life Sciences and in 2010 in a greenhouse. ‘Zilga’ is one of the well adopted cultivars in Estonia, which has been used mostly for producing wine and grown in open field conditions. The aim of the present experiment was to find out the yield maturity parameters of cultivar ‘Zilga’ for red wine in Estonian conditions. Data was collected from the year 2011 to 2013. The bunch weight and °Brix were determined from fresh materials, but all the other biochemical parameters were determined from frozen (-20 °C) grapes. The recommended content (20 °Brix) of soluble solids was not obtained in open field conditions, but reached to 24.1 °Brix in greenhouse conditions in 2013. Titratable acids content was higher than recommended values, ranging from 1.4 to 1.6 mg 100 gE-1 in open field and showing the lowest content (1.2 mg 100 gE-1) in greenhouse conditions. Maturity index values ranged from 117 to 224, and the optimum was reached in two years from three. The highest total phenolics content, 293 mg 100 gE-1 was obtained in 2011, while anthocyanin content was significantly increased in 2013.

The characteristics of the new potato cyst nematode (Globodera rostochiensis, pathotype RO1) resistant, medium ripening potato variety ‘Teele’ (‘Cinja’ ´ ‘Paola’) developed at the Estonian Crop Research Institute (ECRI) is discussed in this paper. The variety ‘Teele’ was included in Estonian and European Variety List in 2013.The variety ‘Teele’ passed the preliminary, dynamic and final trials in 2008 - 2012 at the ECRI, where it was compared with standard varieties ‘Maret’ (early), ‘Piret’ (medium) and ‘Anti’ (late). The official trials in Estonia and the technical examination (DUS test) in Czech Republic were carried out in 2011 – 2012. Potato cyst nematode (Ro1) and wart (Synchytrium endobioticum (Schilbersky) pathotype 1 (D 1)) resistance of the new variety were determined in Poland in the Plant Breeding and Acclimatization Institute. Tuber yield and tuber weight of the variety ‘Teele’ were equal to ‘Maret’ and ‘Anti’ but higher than ‘Piret’. The number of tubers per plant was equal in all standard varieties. Tuber yield and yield of marketable tubers of dynamic trials present the medium ripening of the variety ‘Teele’. The potato variety ‘Teele’ had good quality characteristics (shallow eyes, regular shape) and good culinary traits of table potato variety. It had a relatively good resistance to late blight (Phytophthora infestans) (field resistance), overcoming standard varieties ‘Maret’ and ‘Piret’.

In breeding of Latvian Warmblood breed carriage type horses Equus caballus one of major breeding objectives is producing of typical purebred animals with minimal influence of modern warmblood breeds. The aim of the study was to analyze the quality of Latvian Warmblood horse breed carriage and sport type mares included in the register of Latvian Horse Breeding Association broodmares and differences between types in valuation and quality of progeny. The data included 135 records from Latvian Warmblood horse breed mares having valuation both of conformation and performance. The data from 79 sport type and 56 carriage type broodmares were collected. The majority of mares in population (31.9%) had proportion 0 – 24.9% of Latvian warmblood purebred ancestors. The proportion of Latvian Warmblood purebred ancestors in the group of carriage type mares was high – 72.2%, while sport type mares – only 23.4%, a difference between groups was significant (p is less than 0.01). Sport type mares showed significantly (p is less than 0.05) better results in conformation and performance quality whereas carriage type broodmares had significantly higher count of daughters registered in Stud book. Comparison of breed types showed that groups did not differ significantly by height of withers and quality of progeny. Lower quality of conformation and performance of carriage type had to be explained by pedigree data as the main criteria for acceptance, also with older age of broodmares. For future the main goal has to be censorious licensing of best carriage type stallions and using young broodmares with higher quality of gaits and conformation for breeding purpose.

Antibiotic resistance of Staphylococcus is increasing worldwide. New antibiotics are used in big amounts in the meat production more and more. As a zoonosis, Staphylococcus aureus (S. aureus) is found in various species of animals and people, especially in those, who are working on commercial swine farms and slaughterhouses. The aim of the study was to find out the occurrence of S. aureus in different age groups of pigs on commercial swine farms in Latvia. Microbiological samples (n=702) including nasal, rectal, milk and air samples were collected during October 2013 from three closed farms of different sizes and several age groups of pigs and investigated with microbiological standard methods. S. aureus was found in all swine farms. The occurrence of S. aureus in Latvian pig farms was 41% and the highest occurrence of S. aureus was among 3-3.5 month old piglets. S. aureus was 1.8 times more frequently found in nasal than in rectal samples, and only in 28.38% of pigs S. aureus was in both - nasal and rectal samples. S. aureus was found also in sow milk in 13% of samples and in 3 samples of air (n=23).

The changes of areas of eight tree species in Lithuania during the past century were analysed. Aiming to apply the different approaches in forest studies, the Exponential smoothing method for forecasting the changes of the tree areas for the 25 years was used. The data dating from 1922 was analyzed as a time series. The descending trend was identified for Scots pine (Pinus sylvestris L.) and European ash (Fraxinus excelsior L.) and increasing trend – for Norway spruce (Picea abies (L.) H. Karst.), common oak (Quercus robur L.), birch species (Betula pubescens Ehrh. and Betula pendula Roth), black alder (Alnus glutinosa (L.) Gaertn.), European aspen (Populus tremula L.) and grey alder (Alnus incana (L.) Moench). The Exponential Trend with Multiplicative Seasonality (ET-MS) model was fitted for almost all investigated tree species with exception of European ash. For the latter species, the Damped Trend with Multiplicative Seasonality (DT-MS) model was chosen. Mean absolute percentage error of the model in all cases did not exceed 2%.

In Latvia, Picea abies and Pinus sylvestris as the commercially most valuable species make more than half of all woodlands. It has been found that about 23% of spruce stands are infected by root rot, caused predominantly by fungal pathogen Heterobasidion annosum s.l. To restrict the spread of root rot in coniferous forests of Latvia, the Joint Stock Company ''Latvijas valsts meži'' collaborated with Latvian State Forest Research Institute ''Silava'' in 2006 and launched a project for testing the Rotstop biological preparation, containing a suspension of Phlebiopsis gigantea spores. This project had a general task to accomplish Rotstop using technology approbation in Latvia and develop control system. Starting with the year 2008, preparation was used for stump treatment during thinning operations. When analysing the field data, a conclusion made in other studies was confirmed - P. gigantea colonizes pinewood more intensively even in case of improper stump treatment. It implies that the quality of stump treatment is decisive when using Rotstop for rot control in spruce stands.

Ecological farming is relevant to protected areas. The aim of the study is to perform an analysis of farms applying organic farming measures as well as the analysis of the change of their areas in Aukštadvaris and Krekenava regional parks (RP). The object of the investigation - the farms of Aukštadvaris and Krekenava regional parks. The study is carried out to determine how many farms, forming the regional parks‘ territory, are managed according to the principles of organic farming. The change of the above- mentioned farming area for 2009-2011 is analyzed as well. Paluknys and Naujamiestis subdistricts, not incorporated into the territory of regional parks, were chosen for the comparison analysis. The analysis of the 2009 – 2011 period showed that the declared areas in Krekenava RP have decreased, and the area of farms applying organic measures has increased by 81.69 hectares (nearly 2.5 times). The number of organic farms increased by 1.5 times in Aukštadvaris RP over the period of 2009-2011, and the area has increased by 187.36 ha. The percentage calculations revealed that in 2011 the area of farms applying organic farming measures in Aukštadvaris RP made up 18.89 per cent of the total area declared, the number of farms - 6.61 per cent. The area of farms applying organic farming measures in Krekenava RP was only 1.71 per cent, measures were applied only by 1.89 per cent of all the declared.

The majority of natural Lithuanian rivers were regulated during intensive land reclamation period. Straightening of rivers caused unfavourable conditions for biodiversity. Four tributaries of the Merkys River in the South Lithuania were selected to explore changes in biodiversity patterns and determine the relationships between flow energy distribution in beds and ecological status of selected rivers. The research has shown that variation of cross sections area was usually 1.2 to 2.3 times higher in natural beds as compared to regulated ones. The range of rivers flow energy, estimated by Froude number, values were characterized as higher in natural (0.0 to 0.35) streams than in regulated (0.0 to 0.20) ones. This is the reason why the biggest number of macroinvertebrate taxa during the research period was recorded in natural riverbeds and the lowest - in the fields of the regulated segments. The assessing the abundance of fish revealed that total fish density in natural river sections was four times higher than in regulated ones. The research has approved the importance of naturalness for biodiversity and rehabilitation of regulated rivers in Lithuania.