The objectives of the investigation were to determine the transgressive lines of spring barley (Hordeum vulgare L.) for grain quality traits (1000 kernel weight, and content of crude protein, starch and β-glucans) in the six cross combinations between covered and hull-less barley genotypes. The trial was carried out at the State Stende Cereal Breeding Institute during 2007 and 2008. Lines representing either positive or negative transgression were found in each cross combination if compared covered and hull-less lines with their parent varieties. These lines during the two years of investigation exceeded both parents in positive or negative direction by one standard deviation according to any of the four analyzed grain quality traits. Seven positive transgressive lines were observed regarding 1000 kernel weight, and two transgressive genotypes regarding crude protein content within the population of covered barley lines. No line with positive transgression regarding starch and β-glucan content was found within the covered barley population. 27 hull-less lines showed positive transgression regarding any of the four analyzed grain quality traits. The results show that it is possible to increase grain quality of spring barley grain by implementing selection practices.

The objective of this study was to examine the range of variation and correlation relationships of some grain physical traits of different barley types. Field experiments were carried out at the State Stende Cereal Breeding Institute from 2004 to 2006. Grain samples of 52 spring barley (Hordeum vulgare L.) genotypes were analysed for 1000 grain weight, test weight, relative hardness index and hull content. The mean value of 1000 grain weight and test weight for two-row barley was significantly higher than for six-row barley. Test weight for hull-less barley was significantly higher than for covered ones (mean values - 774.6 g lE-1 and 669.8 g lE-1 respectively). The hull content was higher for six-row barley type (10.4%) than for two-row (8.6%) barley. There was no significant difference in relative hardness index between different types of barley. The coefficient of variation for grain hardness ranged from 13.7% for six-row barley to 18.7% for hull-less barley. Among varieties bred in Latvia relative hardness index ranged from 47.1 for two-row variety ‘Sencis’ to 80.4 for only six-row variety ‘Druvis’. Significant (p is less than 0.05) positive correlation was detected between grain hardness index and β-glucans for covered two-row head types of barley (r2-row, covered =0.418 is greater than r25; 0.05=0.396).

The aim of studies was to identify how different morphological and biological characteristics influence spring barley (Hordeum vulgare L.) competitiveness against weeds in various organic and conventional farming locations. Do those traits have an influence on the yield and in which growing conditions the selection of genotypes for organic farming should be done? The plant traits related to competitiveness against weeds at the beginning of the vegetation period are important in breeding for organic agriculture. Ten different varieties were included in trials for three years in two organic and two conventional environments. The included varieties were divided in four groups with respect to time of release and adaptation to growing environments: old extensive varieties and landraces for low input agriculture, medium old varieties with good adaptation to unfavourable conditions, modern varieties for low input, and modern varieties for high input conditions. Results showed that such traits as productive tillering ability, development speed and plant height at the beginning of stem elongation stage provide good soil shading. The most of traits were negatively related to the grain yield. Selection of genotypes for traits which influence spring barley competitiveness against weeds, such as a growth habit in the tillering stage, development speed in tillering stage, plant height at the beginning of stem elongation, length of flag leaf and the width of flag leaf, and the plant height before harvest, may take place in conventional conditions as well as in organic conditions.

Organic farmers need varieties adapted to variable growing conditions, because in organic farms environmental conditions significantly vary in soil nutrient status, weed and disease pressure not only between years, but also among farms within a season. Modern varieties developed under high input agricultural systems do not always perform well under organic growing conditions. Therefore, farmers need such varieties of cereals that can adapt to variable growing conditions and maintain productivity. One of the ways to promote adaptation to environment is growing of variety mixtures. Field trials were conducted during 2014 – 2016 under organic and conventional farming systems in two locations with an aim to estimate the advantages of barley mixtures in respect of yield and its stability. The trial consisted of eight mixtures of barley varieties and breeding lines, components of mixtures in pure stand and three check varieties. The mixtures were combined by using two, three and five components. Three mixtures, each in one out of 11 environments significantly out–yielded, but one mixture had significantly lower yield than the average value of their components. Some mixtures showed a tendency to out–yield the average of components in both farming systems. All mixtures insignificantly out–yielded check varieties in 2015, but in 2016, yield was within the range between varieties with lowest and highest yield. The results of yield stability analysis showed that mixtures could be used as one of the approaches to stabilize yield – only one of eight mixtures had a lower yield than the average over all environments.

The necessity to increase genetic diversity in agriculture has been widely discussed during the last decades. Heterogeneous populations are one of the ways to increase genetic diversity in varieties of self-pollinating cereals. The aim of this research was to compare grain yield, its stability, foliar diseases severity and competitiveness against the weeds of spring barley (Hordeum vulgare) populations and homogenous varieties. Field trials consisting of three types of populations (simple, complex and composite cross populations – CCP) containing different levels of diversity and three check varieties were carried out during 2015−2018 under organic and conventional farming systems. No one of the populations had a significantly higher average yield than any of the check varieties. CCP1 showed a tendency to be more productive under organic growing conditions and can be characterized as widely adaptable to various growing conditions with a significantly higher yield as the average overall environments. One of the complex populations showed adaptability to favourable growing conditions and yield insignificantly higher than overall average. Other studied populations can be characterized with wide adaptability and various yield levels. For most of the populations under organic and conventional conditions, a significantly lower net blotch (caused by Pyrenophora teres) severity was observed in comparison with the most susceptible variety; infection with powdery mildew (caused by Blumeria graminis) lower than for check varieties was observed under organic growing conditions, whereas such trend was not observed under conventional conditions. All populations had a significantly lower crop ground cover and slightly lower competiveness against weeds than the variety with the best competitiveness

The aim of the study was to compare weed species diversity in organic and conventional farms in Poland. The study was carried out between 2012 and 2014 on production fields located in Lublin province, one of the easternmost regions of Poland. The results showed that diversity and abundance of weeds in spring cereals were generally higher in organic farming system than in conventional one. No significant differences between systems were found in 2013, because local flooding of fields in spring made impossible the execution of agricultural weed management treatment for some farmers. Both above-ground and soil seed bank weed communities were the mainstay of valuable weed species, which is confirmed by the presence of the species threatened with extinction, for example, summer pheasant’s-eye (Adonis aestivalis), poorman’s blue weatherglass (Anagallis foemina) and others in both tested farming systems. Dwarf everlast (Helichrysum arenarium) was the only found species that is subject to partial protection by Polish law. Both organic farms, run under CAP policy and support, and conventional extensive farms of the province of Lublin were the mainstay of biodiversity. Future rural development and CAP should be adapted and implemented regionally. Traditional extensive farms could contribute to the biodiversity and valuable plant species conservation.

Effects of nitrogen fertilizers and weather conditions on spring barley (Hordeum vulgare L.) yield and grain quality were investigated at the Rumokai Experimental Station of the Lithuanian Institute of Agriculture in the period of 1998-2000 and 2003-2004. The soil of the experimental site was Hapli Epihypogleyic Luvisol. Analyses were made with fertilisers rates of 0 and 90 kg haE-1. The data of analyses indicated a positive and reliable correlation between the yield of spring barley and the amount of precipitation in May (rate of correlation was 0.70**) and a negative and reliable correlation with the amount of precipitation in June and July (rates of correlation were -0.80** and -0.29* respectively). A reliable though weak correlation was found between the application of nitrogen fertilisers and the yield of grains. The amount of precipitation in April and the spring barley leaf diseases had a considerable negative effect on 1000 grain weight and grain size. Strong correlation was identified between the amount of precipitation in May and June and the protein content in grain. Nitrogen fertilisers promoted protein accumulation in grain.

The objective of the study was to examine the range of variation in chemical composition of different barley types. Field experiments were carried out at the State Stende Cereal Breeding Institute from 2004 to 2006. Grain samples of 52spring barley (Hordeum vulgare L.) genotypes, including two-row, six-row, covered and hull-less genotypes were analysed for starch, crude protein, crude fat, crude fibre, crude ash and phosphorus. On the average, the six-row barley genotypes had a significantly larger content of crude protein (152.0 g kgE-1), crude fibre (53.5 g kgE-1), crude ash (24.4 g kgE-1) and phosphorus (4.7 g kgE-1) but less starch (590.4 g kgE-1) than the two-row barley genotypes (626 g kgE-1). The hull-less barley grain contained significantly more crude protein (149.4 g kgE-1), crude fat (25.4 g kgE-1) and phosphorus (4.7 g kgE-1) than covered ones. The largest coefficient of variation was found for crude protein of covered barley (15.0%), for crude fibre of hull-less barley (13.8%) and for phosphorus of six-row barley (18.0%) genotypes. Consequently, energetic value was slightly higher in the hull-less barley with waxy type of endosperm, because of the higher fat (27.1-28.3 g kgE-1) and starch content (622.3-680.7 g kgE-1) and less crude fibre (17.3-17.4 g kgE-1) and crude ash (18.9-21.2 g kgE-1) content.

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.

In 2003 and 2004, field experiments with spring wheat (Triticum aestivum L.) were carried out at the Lithuanian Institute of Agriculture in Dotnuva, Lithuania. The aim of the study was to evaluate the effect of nitrogen and sulphur fertilizers on tiller formation and grain yield of spring wheat (variety 'Munk'). N and S fertilizers were applied at 3 rates: N (0, 60 and 120 kg haE-1) and S (0, 15 and 30 kgE-1 ha). Both years, N fertilization had a significant effect on tiller formation. At harvest, the total number of tillers was approximately 0.5 tillers higher in the plots with the application of N120. The growing season in 2003 was comparatively dryer, and a significant increase in grain yield was found - up to 60 kg haE-1 of N. Due to higher rainfall in 2004, grain yield was much higher and the highest effect was found with the maximum N supply - 120 kg haE-1. One thousand grain weight was influenced by the year, while fertilizers did not have any significant effect. The impact of S fertilization on the number of tillers and final grain yield was insignificant; nevertheless S fertilization increased the concentration of S in the aboveground plant mass.