Oregano (Origanum vulgare L.) is one of the most popular spice and medicinal plants of untraditional horticulture in Latvia. Wild populations of this plant are too few. That is why it is necessary to cultivate oregano for keeping the biodiversity of Latvian nature. It is important to use local oregano genetic resources in agrocenosis as well as to get as rich and qualitative yield as possible. The aim of this research was to explore the parameters of oregano inflorescence in Latvia and to recommend the most productive clones for cultivation. In summer 2011, a total of 45 oregano clones from an ex situ collection of spice and medicinal plants of the Laboratory of Cultivated Plants and Apilogy (Jelgava, Strazdu Street 1) were analysed. Such inflorescence parameters as length and width were explored. The average length of inflorescence of all clones was 17.99 cm, and the average width was 5.74 cm. The results showed that the clone No 26 had the largest width of inflorescence (9.6 cm), but the clone No. 2 had the largest length of inflorescence (31.1 cm). Using oregano Draft Descriptor List, the inflorescence was characterized as short, medium or long. The variability between clones was significant (p is less than 0.05), but between samples of each clone - non-significant (p is greater than 0.05). It is recommended to grow oregano clones No. 2, 5 and 26 in agrocenosis as the most productive.

Advances in milk production and the expansion of dairy herds have increased the need for improved manure management and whole farm nutrient balance. It is well known in dairy management that the balanced feeding and holding technology is an important level by which milk production and milk composition can be modified. The objective of this study was to evaluate urea content and urea yield in different farms with different holding technologies. Four farms represent three cow breeds (Holstein Black and White, Latvian Brown, and cross breed XP). Individual cow milk samples (n=2740) were collected monthly from September 2009 to November 2010. Milk samples were analyzed for total protein, casein, fat, lactose, and urea content with instrumental infrared spectroscopy method. The average milk yield per cows in farms was significantly different (from 27.9 to 17.0 kg per control day). The urea content in cow milk was between 20.3 to 46.6 mg dLE-1. The average urea content in farms A, B and D was up to standard (from 15.0 to 30.0 mg dLE-1). In the farm C, average urea content ranged between 17.4 and 79.9 mg dLE-1, which indicated problems in feeding or management in the farm. It was established that milk urea content and yield significantly (p is less than 0.05) varied in farms with different dairy cow holding and feeding technologies. Urea content can be used to evaluate feed protein utilization in farms and predict environmental pollution.

The aim of air pollution monitoring is a regular and continuous collection of information on air pollution to prevent hazards influencing ecosystem and its components, including humans. Nowadays, the main technology used for this purpose is electronic sensors. As they are designed for specific measurements, a lot of important factors cannot be evaluated – various pollutants diffusion or cumulative effect, exposure, dose, and bioaccumulation. As an alternative solution – bioindication – pollution level determination from its effect on certain indicator species can be used. So far potential usage of bioindication as current air pollution monitoring network’s equivalent solution has not been studied. Therefore, the aim of the research was to assess a variety of bioindication methods for air pollution determination and their applications in air pollution monitoring. During the research, commonly used bioindication methods based on their popularity in scientific literature in 2012 were selected, as well as they were assessed using theoretical analysis method in order to determine their strong and weak points in air pollution monitoring. Research results demonstrate that current bioindication methods are not suitable for monitoring purposes. Therefore, bioindication can be combined with citizen science approach. To incorporate citizen science approach in bioindication based air pollution monitoring, development of special, for this purpose designed bioindication methodology is needed.

Blueberry cultivation is becoming more and more popular in Latvia, and several commercial plantations have been established recently. Highbush blueberries (Vaccinium corymbosum L.) are perennial and can grow without replanting for 50 years; therefore a choice of soil and its preparation have a great role. This article summarizes results of research carried out in commercial blueberry plantation established in 2004 on loamy Haplic Cambisol. Soil properties, especially reaction and organic matter content, initially were not suitable for blueberry cultivation, therefore deep tillage and application of soil conditioner (acid sphagnum peat) were done before planting and similar peat mulch was applied every second year. Berry yield of 4 blueberry cultivars, soil properties and the nitrogen, phosphorous and potassium content in growing plant leaves were determined. The obtained results showed that sphagnum peat is an effective material for lowering of soil pH in plant root layer (0 – 40 cm). Data about plant nutrient content in topsoil and subsoil as well as in growing plant leaves will help to develop criteria for soil fertility assessment and diagnosis of plant nutrition.

The objective of the present study was to investigate the microbiological content of cows’ milk in Latvia’s organic farms with a purpose to detect potential microbiological threats in milk. Samples were collected in December 2011 at 12 biological dairy farms of Latvia. Raw milk samples (N=155) obtained from cow composite milk were studied. The total mesophilic aerobic and facultative anaerobic microorganisms (MAFAM), the presence of coliforms and coagulase-positive staphylococci, count of yeasts and moulds were analysed using standard methods. Of the sampled cows 50% had a low somatic cell count (SCC) (LESS THAN 200,000 cells mLE-1), 23% - high, but 27% had a very high SCC (greater than 500,000 cells mLE-1). The mean value of MAFAM in the samples with low, high and very high SCC was 4.7, 5.0 and 5.0 log10 colony forming units (cfu) mLE-1, respectively. The yeasts were present in 57% of milk samples with the mean concentration of 3.1 log10 cfu mLE-1. Moulds were found in 27% of all milk samples; their mean concentration was 4.4 log10 cfu mLE-1. Identified mould strains belonged to genera Absidia, Aspergillus, Geotrichum, Mucor and Penicillium. In cases of subclinical mastitis and latent mammary infection the most distributed mastitis pathogens were Staphylococcus aureus, Micrococcus kristinae, Bacillus cereus and coagulase negative staphylococci.

The collection of 82 collection numbers of the plant Symphyotrichum Nees genus has been accumulated in the period of 1923 - 2018 at Vytautas Magnus University Botanical Garden. The collection consists of Symphyotrichum cordifolium, S. dumosum, S. ericoides, S. laeve, S. lanceolatum, S. lateriflorum, S. novae-angliae, S. novi-belgii, S. oblongifolium, S. pilosum, S. × salignum, S. tradescantii, S. turbinellum, S. urophyllum, and their infraspecific taxa and cultones. The major part of the collection consists of S. novi-belgii (32 collection numbers) and S. novae-angliae (19 collection numbers) infraspecific taxa and cultones. 57 collection numbers were acquired by sproutings from other botanical gardens, private collections, nurseries, the origin of 21 collection numbers is unknown, 4 collection numbers were acquired by seed exchange with other botanical gardens. Phenological observations and biometric measurements of plants were performed according to methodological manual "Methodology of phenological observations, biometric measurements and assortment formation of ornamental herbaceous plants" prepared by J. Vaidelys in 2005. When assessing the phytopathological status of plants, powdery mildew (Erysiphe cichoracearum) was determined as the main disease affecting the plants. S. dumosum and S. novi-belgii interspecific taxa and cultones were the most susceptible to the disease. Plants grown in the same location for more than 3 years were more susceptible to the disease. The aim of the study was to review the Symphyotrichum collection and to evaluate the susceptibility of different groups of cultivars to powdery mildew.

The broadbean seed beetle (Bruchus rufimanus) is a significant pest of faba bean (Vicia faba) both in Latvia and in many other parts of the world. The objective of this study was to check the susceptibility of the faba bean variety ‘Merkurʼ to the broadbean seed beetle in Latvia, comparing it with other popular varieties: ‘Boxerʼ and ‘Lauraʼ. The trials were conducted in 2021 and 2022 at the Research and Study Farm ‘Peterlaukiʼ in Jelgava County and at a commercial farm in Cēsis County. The larval infestation rate of seeds of different varieties, the survival rate of individuals (larvae, pupae, imagines) in the seeds, as well as the percentage of seeds damaged by the pest in the yield were compared. It was observed that ‘Merkurʼ seeds were significantly less infested than ‘Boxerʼ and ‘Lauraʼ seeds. However, the survival rate of larvae in the seeds of ‘Merkurʼ was similar to that in ‘Lauraʼ seeds and higher than in ‘Boxerʼ seeds. The highest proportion of seeds damaged by the pest was found in the ‘Merkurʼ and ‘Boxerʼ yields, varying between 5–75% between years and trial locations. Therefore, it was concluded that the variety ‘Merkurʼ, evaluated from a practical point of view, does not differ from the other two varieties. Without taking additional plant protection measures, the percentage of seeds damaged by the broadbean seed beetle can significantly exceed the maximum limit (3%) specified in the buyersʼ quality criteria.

In Uzbekistan, the main food product is bread, which is produced in various forms from local and imported wheat. Most of it is not studied by microelement analysis. The objective of this study is to quantify trace elements in locally produced wheat from various cultivated regions of Uzbekistan. Four different varieties of wheat are cultivated in Sirdarya, Tashkent region, Kashkadarya and Fergana were selected for analysis. Next, a comparative analysis of the elemental composition like iron, zinc, potassium, calcium etc., in the selected samples were studied. To carry out the above aims, an innovative research method was chosen, which is called improved instrumental neutron activation analysis. This method differs from others in its high accuracy in determining trace elements and its multi-element nature. Using this method, we can understand how insufficient nutrients are in baked goods made from wheat grain grown in Uzbekistan. Based on the results of the study, it can be recommended to enrich the soil with fertilizers high in iron and zinc. As a result, in turn, will have a positive effect on the health of the population, since today there is a shortage of the above listed elements. It was also revealed that the concentration of potassium and calcium in wheat cultivated in Uzbekistan is in a high state than other elements. Using the chosen method, two toxic elements were determined and according to the analysis for toxic elements, all four samples are recommended for consumption, as they do not exceed the permissible level for food safety.