A study was conducted to determine efficiency of an organic acids and phytogenic additives on pigs' growth processes and digestive tract microflora. The feed of the control group (C) did not contain the additives. The feed of the organic acid group (A) contained 6 kg of organic acids additive per tonne feed for pigs after weaning, 4 kg per tonne feed for grower pigs, and 3 kg per tonne feed for finished pigs. The feed of the phytogenic additive group (F) contained 0.5% of phytogenic additive per tonne feed for pigs after weaning, and 0.2% per tonne feed for grower and finished pigs. The feed of organic acids plus phytogenic additives group (A+F) contained 6 kg of organic acids additive per tonne feed for pigs after weaning, 4 kg per tonne feed for grower pigs, and 3 kg per tonne feed for finished pigs 0.5% of phytogenic additive per tonne feed for pigs after weaning, and 0.2% per tonne feed for grower and finished pigs. Compared to groups pigs from the group (F) had by 9.7%, group (A+F) - by 8.3 % and from group (A) had by 3.2% higher mass. The bests results of feed conversion were found in the group (A+F) - 2.84 kg, which was by 8.5% less than in the group (C), whereas the group (F) had by 5.1% and group (A) - by 6.7% better results than the control group. The results of Duodenum and Rectum microflora analyses showed that use of organic acid and phytogenic additives reduced mould yeast Staphylococcus sp. colony formed units (CFU gE-1).

Sowing area under oil-seed rape (Brassica napus L.) has grown dramatically only during the last 10 years in Latvia. Lack of knowledge and research on different issues is observed. The aim of our research, started on season 2005/2006 in Research and Study farm Vecauce, was to investigate the influence of split fungicide (1st dose of fungicide Juventus 90 s.c. (Metconasol 90 g LE-1) used as growth regulator in autumn at the 4-6 leaf stage and the 2nd dose at the growth stage 63-64) application. Winter rape development in autumn, winterhardiness, disease incidence, and yield and its structure elements were estimated. Totally 13 cultivars were used in the trial, but several assessments were done for 5 cultivars. Additional objective was to evaluate economic effect of fungicide use. Winter rape biometrical indices were influenced by the fungicide application in autumn period and by used cultivar. Fungicide treatment in autumn increased also the rape winterhardiness. Our research for the first time indicated that Phoma stem canker could become a problem for rape growers in Latvia. Fungicide use (in growth stage 63-64) decreased incidence of this disease a little (on average by 5%). Fungicide treatment according to applied scheme increased the average seed yield (check 5.37 t haE-1, with fungicide 5.80 t haE-1; LSD0:05 = 0:18 t haE-1), but impact on yield structure elements was mainly non-essential. Despite agronomic improvements, economic calculation showed that on average fungicide use in 2006 was not pro table. Research should be continued for specification of conclusions.

Cereals, the yield of which is strongly influenced by a well-selected variety, belong to the most important crops of organic farming, grown on arable land. At first a questionnaire study was executed among organic farmers in 2006 to gain information concerning the choice of variety, structure of growing, and yield of cereals in the Czech Republic. The actual cultivars of wheat are bred to be suitable for intensive farming. Therefore, not all the actual cultivars are suitable for organic farming. The methodology of tests of the suitability of cultivars for organic farming was elaborated and tested in 2006. Particular morphological, biological and agricultural features were evaluated. Selected Austrian cultivars, which were recommended for in organic farming system and breeded strains were tested. It is difficult to achieve sufficient protein content in grain in the organic farming system. The fact that the protein content in landraces of wheat is higher than the protein content in modern breeded varieties was confirmed. These varieties adapted to local conditions very well. Most of the evaluated varieties contain more crude protein in grain than modern varieties and may achieve a very good-quality production, but on a lower yield level the same as varieties of emmer.

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.

The research was done in 2006 with the aim to observe the earliness and sugar content of melons (Cucumis melo L.) in Tukums region of Latvia. Five lines of Latgale's melons ('8', '14', 'S4(3)', '5(2)', and '4(3)') and five varieties ('Noirdes Carmes', 'Ogen', 'Vedrantais', 'Cantaloup de Bellegarde', and 'Jaune Canaris') from South Europe were grown in high plastic tunnels: five plants from each line and variety. The most appropriate melon line for growing in Latvia conditions was selected according to earliness and sugar content. The study showed that Latgale's melons (Latvian origin) are most suitable for growing in high plastic tunnels under Latvia's conditions. Also some of South Europe melon varieties proved to be suitable for growing in Latvia conditions. All Latgale's melon lines were earlier than South Europe varieties. The highest sugar content was observed in Latgale's melon line '8' (113 g kg¡1) and in South Europe varieties 'Jaune Canaris' (110 g kgE-1) and 'Cantaloup de Bellegarde' (96 g kgE-1). The research demonstrated that in Latvia successful cultivation of melons is possible by using high plastic tunnels.

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.

The aim of this research was to compare effects of fertilization with various ratios of N, P and K (N:P:K) on arbuscular mycorrhizal fungi (AMF) infection in roots of Dactylis glomerata in Ca-carbonate (limed) and non-limed meadow plots at the Research Centre of Skriveri, Latvia University of Agriculture. Dactylis glomerata roots were excavated from variously fertilizer plots, a minimum 3 root samples per plot and analysed for two consecutive years. Arbuscular mycorrhizal fungi infection rates were estimated according to accepted scoring tables used for determination of AMF colonization.