The aim of this study was to evaluate the genetic and environmental variation of yield and food quality characteristics (protein, starch, β-glucan and husk content, test weight and thousand grain weight) of covered and hulless barley genotypes in organic management conditions. Two different field experiments were carried out. In the first experiment, hulless barley genotypes 'Kornelija', 'Irbe', '1165', '1185' and the covered varieties 'Ansis' and 'Maali' were studied in two locations in Latvia and in one location in Estonia during 2014. 'Ansis', ‘Kornelija', '1165' and '1185' were included in the second experiment carried out at Stende during three sequential years (2011-2013). The effect of genotype, environment (location and year) and co-effect of these factors contributed significantly to the variation in yield and grain quality traits of the barley genotypes. As a result of experimental treatments grain yield and quality traits varied by all tested factors. There were considerable differences in impact of studied sources of variation. Grain yield was influenced more by environmental factors than by genotype. Impact of genotype was highest for husk content and test weight. Integral evaluation method was carried out for comparison of barley genotypes to identify the best ones by the lowest deviation from the desired value. The covered barley variety 'Maali' showed good adaptation to different environmental conditions, having good yield, β-glucan content and high thousand grain weight. The line '1165' and variety 'Kornelija' showed best results among hulless barley varieties

Pyrenophora teres (net blotch) and Cochliobolus sativus (spot blotch), the most widely spread diseases in the Northern Baltic region, have high impact on cereal production. The effect of three levels of fertilisation and two fungicide treatments on the severity of barley diseases, grain yield and quality traits (protein content, test weight, thousand kernel weight (TKW), grading) was tested during a period of three years. Weather conditions during the growing season highly determined disease severity, yield and quality. In addition, the infection level of P. teres was more dependent on fungicide treatment (p ≤ 0.001) and barley variety (p ≤ 0.001) while C. sativus infection was influenced more by fertilisation (p ≤ 0.001) and year x fertilisation interaction (p ≤ 0.001). Fungicide treatment had no influence on grain yield and protein content, but slightly improved TKW (p ≤ 0.05), test weight (p ≤ 0.001) and grading (p ≤ 0.001). However, these quality traits were mostly influenced by barley variety (p ≤ 0.001). TKW and test weight were highest at fertilisation level N80P12K43. The effect of year and fertilisation contributed significantly to the grain protein content. Grain yield and protein content were highest at the maximum fertiliser application (N100P15K54).

SUMMARYResearch and development related to the naked oat is now becoming more wide-spread as the opportunity for its different uses is understood also in Latvia. It has been recognized as a more valuable product in the food industry because both the interest of consumers in their health and the promotion of food products are increasing. Naked oat kernels contain high levels of β-glucans and unsaturated fatty acids. The aim of the study was to evaluate the yield and oat grain quality of naked oat breeding lines from Latvian oat breeding program. The following parameters were assessed -grain yield, 1000 grain weight, test weight, crude protein fat and β-glucan. The research assessed the variability of these parameters in organic and conventional farming system (at three different mineral fertilizer rates: N80, N120, N160). The field experiments were carried out at the State Stende Cereal Breeding Institute during three years (2011)(2012)(2013). Results showed that the higher N fertilizer rate positively affects the amount of the crude protein and β-glucan in naked oat grains. The farming system (η 2 =42.9 %) and testing year/meteorological condition of years (η 2 =35.9 %) had a greater impact on naked oat yield. Comparing only N80, N120 and N160 variants in conventional system it was observed that during the three year period the meteorological conditions had the greatest impact on the yield of naked oat (η 2 =86.6 %). Naked oat line 'S-156' gave the highest grain yield in conventional and organic farming systems and formed significantly higher crude protein, fat and β-glucan amounts in the grain.

Cereals, especially barley, are an important source of vitamins, minerals, dietary fibre and various phytochemicals, such as alkylresorcinols (ARs). Cereal ARs are a group of phenolic lipids located in the outer parts of grain, particularly in rye and wheat, but not found in refined flour or in refined products from cereals. This study focuses on the comparison of different extraction procedures applied for the determination of the content of ARs (C15:0 - C23:0) in grain of Latvian barley genotypes. The content of ARs in 1 rye and 16 barley samples grown with different amounts of fertilier was determined by High Performance Liquid Chromatography method with Photodiode Array detection (HPLC-PDA) developed by us. Two different extraction methods were compared: accelerated Soxhlet extraction and 24-hour extraction. Aside from validation of the extraction procedures, validation parameters for the HPLC-PDA based quantitation method were provided. The coefficients of variation for repeatability and intermediate precision were < 9% and < 3%, respectively. The content of ARs determined with the HPLC-PDA method in conjunction with accelerated Soxhlet extraction was up to 1.5 times higher than using 24-hour extraction. AR content varied from 2.11 ± 0.04 to 3.80 ± 0.10 mg·100 g-1 for 24-hour extraction and from 2.66 ± 0.06 to 5.70 ± 0.20 mg·100 g-1 for accelerated Soxhlet extraction, indicating the increased efficiency of this procedure in analysis of ARs.