Another important aspect of an effective market is the quality of the goods that are sold. Standards to ensure the quality of goods are thus significant determinants of the effectiveness and productivity of markets. For the purpose of promoting competitive markets as well as protecting consumers from dangerous and unsafe products that may be found in the markets, the state can take a leading role in setting and enforcing quality standards.

Within the frame of the Nordic/Baltic public-private partnership ’PPP for pre-breeding in perennial ryegrass’ various activities were performed, including assessment of L. perenne (Lp) genotypes under agro-ecological conditions of Latvia. This article summarizes the data obtained in two harvest years for 19 intermediate tetraploid (4x) Lp genotypes. In order to compare the results obtained in ryegrass with performance of grass interspecies hybrids (Fl), which become especially relevant in the recent years, two varieties, developed in Latvia – Lolium × boucheanum Kunth. ‘Saikava’ and × Festulolium ‘Vizule’ were included in the experiment. Various scores were performed, including evaluation of regrowth, intensity of culm development, sward cover, crown rust (Puccinia coronata) susceptibility, etc. The dry matter yield (DMY) and fodder quality were also determined. It can be concluded that the genotypes showed relatively good results in the first two harvest years. Wintering conditions were favourable. Despite the intensified drought and heat in the 1st ley year, relatively high DMY, which ranged from 9.30 to 12.15 t haE−1, for Lp were harvested in three cuts. In the 2nd ley year, under more favourable humidity conditions, Lp in four cuts provided similar DMY, which ranged from 8.81 to 11.50 t haE−1. If we compare the average DMY of Lp and Fl genotypes, it can be concluded that in the first two harvest years no significant differences were found, the average DMY was 10.30 and 10.64 t haE−1, respectively. No significant differences were found between Lp and Fl in terms of forage quality.

Pyrenophora tritici-repentis is a major wheat pathogen in all wheat (Triticum spp.) growing areas worldwide. Up to date, eight P. tritici-repentis races have been described based on chlorosis, necrosis, or both symptoms caused on race differential wheat genotypes: ‘Glenlea’, 6B662, 6B365, and ‘Salamouni’. Symptom development on differential genotypes depends on the interaction of the pathogen’s necrotrophic effectors named Ptr ToxA, Ptr ToxB, and Ptr ToxC with host susceptibility genes. Ptr ToxA is encoded by the single copy gene ToxA and induces necrosis on sensitive wheat cultivars. Ptr ToxB causes chlorosis and is encoded by the multicopy gene ToxB. The Ptr ToxC is the non-proteinaceous, polar, low molecular mass molecule that also induces chlorosis, but up to date, the gene encoding this toxin is unknown. Races producing Ptr ToxA are predominant in the global Ptr population. There are several reports about new putative races of P. tritici-repentis that do not conform to the current race system, so further research is required. This study aims to collect and systematise available information about the virulence and races of P. tritici-repentis.

Latvia University of Life Sciences and Technologies and Organizing Committee of Annual 26th International Scientific Conference on Research for Rural Development 2020 tried to continues a tradition of bringing together researchers, academic and professionals in Jelgava, from 13 to 15 May, 2020 from all over the world. But, unfortunately, this year the rules were set by the coronavirus disease (COVID-19) pandemic. We did start new tradition from 2020, account from 1st until the 26th conference and totally are 35 volumes. The interdisciplinary papers contributed the most recent scientific knowledge in agricultural sciences, forestry and wood processing, food sciences, veterinary medicine, economics, rural and environmental engineering, water management; information and communication technologies and education. These Proceedings will furnish the scientists of the world with an excellent reference volume. We trust also that this will be an impetus to stimulate further study and research in all these areas.

The four independent reviewers estimated each paper and recommended 81 articles for publishing at the proceedings consisted of 2 volumes, which started life as presentations at the Annual 23rd International Scientific Conference “Research for Rural Development 2017” held at the Latvia University of Agriculture, in Jelgava, on 17 to 19 May 2017. In the retrospect of four months later, we can count the Conference as a great success. The theme – Research for Rural Development - attracted participation more than 155 researchers with very different backgrounds. There were 124 presentations from different universities of Poland, Kazakhstan, France, Czech Republic, Lithuania, Estonia, India, Russia and Latvia. Thank you for your participation! We are sure that you have learned from the presentations and discussions during the conference and you can use the outcomes in the future. The cross disciplinary proceedings of the Annual 23rd International Scientific Conference “Research for Rural Development 2017” (two volumes since 2010) are intended for academics, students and professionals. The subjects covered by those issues are crop production, animal breeding, agricultural engineering, agrarian and regional economics, food sciences, veterinary medicine, forestry, wood processing, water management, environmental engineering, landscape architecture, information and communication technologies. The papers are grouped according to the sessions in which they have been presented.

Modern varieties developed under conventional plant breeding programs do not always perform well under organic and low-input growing conditions. Therefore, organic farmers need varieties adapted to variable environmental conditions. This means emphasis on traits such as nutrient uptake and use efficiency, good weed suppression ability and disease resistance and can be achieved via extended genetic diversity within the varieties: variety mixtures and populations of self-pollinating crops. The aim of the present study was to review published scientific literature about importance and research results on this topic. Scientific articles about the necessity of such studies and results of investigations performed in different countries have been studied. The main results show that variety mixtures have advantages in terms of disease control and yield stabilization and performance of mixtures may be affected by various factors – choice of components and its number, interactions between plants of components, manner of the mixing and growing technology. Depending on parental material, populations contain greater genetic diversity than variety mixtures. There are trends observed in the studies that yield of populations increased over generations and they are more stable than modern varieties, but there is no evidence that they would be significantly more productive. This research direction has recently become topical and is not sufficiently widely covered in the world agricultural science. The obtained results are inconsistent.

The objective of the study was to detect the difference of the conformation scores between dams and daughters in Latvian Warmblood horse breed. For this purpose the correlations and regression coefficient between conformation traits of broodmares and the same traits of their daughters were estimated. Data of Latvian Warmblood horse breed broodmares were analyzed. The horse breeding organisations’ evaluating data from 1995 till 2015 were analyzed. The data included conformation valuation of Latvian Warmblood horse breed dams (n = 423) and their daughters (n = 596) of different ages. An average in ten-point scale in the group of dams was 7.71 ± 0.04 for top line scoring, 7.33 ± 0.05 for forelimbs and 7.35 ± 0.05 points for hind limbs. An average of valuation points of their daughters was 7.51 ± 0.03 for top line scoring, 7.21 ± 0.04 for forelimbs and 7.21 ± 0.04 for hind limbs. A significant difference between valuations of dams and their daughters (p0.05) was found for all three conformation traits. Positive and low correlation was calculated between groups of dams and daughters for all three conformation traits. The results show that the relationship between conformation traits of dams and daughters was weak. Further studies are needed in order to estimate influence of broodmare quality to daughters, analyzing the latest data of progeny.

The article analyses the data obtained while evaluating red deer calves on the red deer breeding farm ‘Dumpji’ during the herd’s annual prophylactic check-up in December and April of the years 2013 and 2014. Farm is a private enterprise owned by a company located in Northern Latvia. The study comprises data for calves born in 2013 (n = 36) that were born from the same hinds, but from different stags in consecutive years. It was discovered that the calves’ liveweight gain in 24 hours significantly decreases during wintering period. After the wintering smaller body mass was observed in calves of both sexes born in 2014; however, the body mass of bull calves born in both years of reference considerably exceeded that of the hind calves. In the group of hind calves born in both years of the study period the liveweight loss was observed during the wintering. Nevertheless, at the age of 1.5 years the lowest liveweight among hind calves was 82.4 kg (year 2013), and the highest 129.6 kg (year 2014). In the group of spikers, during the winter period liveweight loss was not observed. Analysis of the results revealed a close positive correlation between the liveweight in December and the liveweight in the spring among spikers and heifers alike. The conducted analysis of influencing factors attests to the fact that the liveweight at the age of six months has material impact on the animals’ liveweight both in the spring and at the age of 1.5 years.

The aim of this review was to summarize available bibliography on the possible applications of high pressure processing in dairy industry, the effect of this non-thermal treatment on bacterial microflora and milk constituents. Traditional thermal treatments applied to milk processing lower nutritional quality because many nutrients are heat labile. To overcome this problem, several non-thermal processing technologies including high hydrostatic pressure (HHP) processing have been developed. Pressures between 400 and 600 MPa inactivate microorganisms including food-borne pathogens; however, high pressure (HP) injured bacteria in milk during storage can recover. All enzymes are inactivated only at pressures of 800 MPa. During HHP the casein micelle size decreases, whey proteins are denaturated, the level of free fatty acids increases. These characteristics indicate that for better understanding and application of HPP in dairy industry research should be done to offer the numerous practical applications to produce microbially safe, minimally processed dairy products with improved performances, and to develop novel dairy products of high nutritional and sensory quality and increased shelf life.