Evaluation of Lucerne Cultivars for Dry Matter and Seed Production in Latvia

Lucerne is highly productivity and has a high quality. Nevertheless, lucerne growing in Latvia is limited, because of a large area of acid soils (pHKCl\u3c5.8) as well as low and unstable seed yields (Berzins, 2002). In recent years lucerne has taken a more important place in forage production in Latvia, because it is a fast growing crop and in good years gives 3-4 harvests per season. It is important to determine which cultivars of lucerne are more productive and give good seed yields every year in Latvia (Luksa, 2002)

The Productive Longevity Of Perennial Grasses Swards Depending On The Npk Fertilizer Rates

The longevity and producing capacity of perennial grasses swards was studied on mineral soils at the LUA Research Institute of Agriculture in long-term experiment during 1974-2010. There were applied lime and mineral fertilizers with different NPK doses (0-400 kg ha-1) protractedly many years. In such way there formed soils with various content of P, K, organic matter content and pHKCl level as well. Research results showed that liming of soils and using of mineral fertilizer changed not only productivity of grass mixtures but also botanical composition. Mineral fertilizer N200P100K300 provided the highest yield of dry matter – 7.32 - 12.0 t ha-1 and optimal botanical composition of a sward during many years. On unlimed soils (pHKCL less then 4.0 in 1997) dry matter yields of grass sward was substantially lower and there was observed disappearance of seeded valuable grasses out of the sward and increase of herbs and non-seeded grasses –Festuca rubra L., Agrostis tenuis Sibth., Taraxacum officinale Wigg. and others. Liming of soils increased dry matter yield in treatments with high doses of N (300-400) fertilizer

Seed Yield of Herbaceous Crops under Agroforestry System

Agroforestry is a perspective way of biomass production which combines simultaneous growing of woody plants with agricultural crops on the same area for different purposes (Reisner et al., 2007). Agroforestry like multifunctional agriculture has the objective of promoting economically, socially, and environmentally sustainable rural development (Leakey, 2012). It is more sustainable than the monocultures of forestry or agriculture separately. Agroforestry can be an appropriate technology in the areas with fragile ecosystems and subsistence farming. The main advantage of this technology is improved efficiency of resource utilization and smaller competition of plants for nutrients (Bardule et al., 2013). Agroforestry has the ability to provide short-term economic benefits while the farmer is waiting for traditional long-term forestry products. In the system of agroforestry perennial herbaceous plants can be successfully cultivated along with fast-growing trees for different purposes. There is an opportunity to place various herbaceous crops species for seed production, including crosspollinated crops in the cultivation of which it is important to comply with spatial isolation. Perennial grasses and legumes have been widely used as fodder crops for centuries and there has been an increasing interest in the use of them as energy crops because they have many economic and ecological advantages. Both woody and herbaceous crops need fertiliser for increasing productivity and it is a good opportunity to use various by-products for this purpose in the agroforestry system. The investigation was performed on the seed production of herbaceous plants cultivars grown in columns alternated with aspen rows and fertilized with residual materials - wood ash and wastewater sludge that contain chemical elements with considerable fertilizing value

The Results of Breeding Perennial Grasses: The Evaluation of Developed \u3cem\u3eDactylis glomerata\u3c/em\u3e Hybrids

Perennial grasses are high yielding, pest resistant and less demanding in terms of soil (Peeters, 2008), they are the most important source of roughage. Each species has certain valuable features that make it unique among others and which are desirable to be highlighted for ensuring high productivity, good forage quality, plasticity, strength of various stress conditions, as well as winter hardiness, which is particularly important characteristic of northern latitudes. It is the main task of breeders, as far as possible to combine all the aforesaid properties into one breed. In order to create such a universal variety the breeders of perennial grasses carry out hybridisation outside the borders of one species. At present the work with Festulolium hybrids is important in order to combine the modesty, hardiness and perennity of fescue with high forage quality characteristic of ryegrass in one variety. At the Latvia University of Agriculture Research Institute of Agriculture (LLU RIA) in Skriveri the breeding work of perennial grasses has been performed for a long time and during the period of 35 years several varieties of species widely used in forage production have been created, including Phleum pratense, Lolium perenne, Festuca pratensis, and Festulolium hybrids

Effect of Lignosilicon on the Content and Antioxidant Activity of the Polyphenols of Buckwheat Fagopyrum esculentum Moench

Lignin preparations, introduced into soil jointly with buckwheat Fagopyrum esculentum Moench, variety 'Aiva' (cultivated throughout Latvia) seeds during the sowing in quantities of 20 kg ha-1 and 40 kg ha-1, exerted a favourable effect on the ned in alcohol extracts from the biomass of different morphological parts of buckwheat, were represented mainly by rutin. The content of rutin in the ethanol extracts from the biomass of flowers with bract reached the maximum values in the phase of accomplishing blooming - beginning of fruit formation to be 2.74% in terms of dry mass (exceeding the rutin content development of plants and the synthesis of flavonoids in flowers with bract. Flavonoids, determin the control by 65%) in the variant with 40 kg ha-1 of Lignosilicon. Lignin preparations favoured the increase in the radical scavenging capacity of the alcohol extracts of the biomass of flowers with bract of buckwheat, as well as grain and hulls. The increment of the buckwheat grain crop, in comparison with the control on the background of 40 kg ha-1 of lignin, was 12%, and that on the background of 20 kg ha-1 and 40 kg/ha of Lignosilicon 10% and 15%, respectively

REED CANARY GRASS (PHALARIS ARUNDINACEA L.) IN NATURAL BIOCENOSIS OF LATVIA, RESEARCH EXPERIMENTS AND PRODUCTION FIELDS

Abstract In recent years, perennial grasses have not been considered only as a forage crop but focus has shifted to their usage as an energy crop. Special interest has been caused by reed canary grass, which is widely spread in natural biocenosis. The scientific expeditions have been organized and all regions of Latvia have been explored to gather material and information about biodiversity of perennial species of wild grasses. Several natural populations of reed canary grass (Phalaris arundinacea L.) were collected under different soil and climate conditions. The accessions were of different quality in many respects depending on collection site. Samples taken from the marshy meadows on lakeshore of the Lake Lubana were coming into flowers unevenly over a longer period of time and formed a little number of culms, whereas samples collected on the banks of the River Daugava were earlier and formed considerably more culms and were coming into flowers evenly over a shorter period of time. Breeding on reed canary grass in Latvia has not been done previously. Attention to the wild populations of RCG usually has been focused on their feeding value. Though, these populations have a good potential for selection of a new varieties intended for varied purposes. The field trials with ten wild accessions of RCG were established, and winter hardiness, growth intensity and various phenological observations were evaluated. After a comprehensive evaluation of the wild populations by important economic and morphologic characteristics, some valuable samples were found. The population 'Brigena' proved such valuable characteristics as good winter hardiness, high dry matter yields, and intensive development of productive culms. In recent years, consumption of reed canary grass as energy feedstock has increased rapidly in Latvia. It is grown by farmers in all regions and the total planted area has exceeded 800 ha. Mostly are grown varieties 'Marathon' (USA) and 'Bamse' (Sweden). DM yields obtained by farmers in Latvia on average are 6 -9 t ha -1 . Further research has to be continued

Carbon and nitrogen uptake in above- and below-ground biomass of cereal crops in the integrated farming system

Received: February 1st, 2023 ; Accepted: April 8th, 2023 ; Published: April 24th, 2023 ; Correspondence: [email protected] significant reduction in greenhouse gas (GHG) emissions, as well as technologies that ensure removal of CO2 from the atmosphere, are necessary to achieve the set goals for the transition to carbon neutrality. During the crop growth cycle, a significant amount of biomass is produced, and carbon (C) and nitrogen (N) are captured both by the harvested crop removed from the field and by residues left on the field. The trials were conducted to find out patterns between crop and residues while trying to figure out the amount of captured C and N. In this study data of the most widely grown cereal crops in Latvia are summarized. The data are representative, obtained in different agroclimatic conditions, they vary both by species and variety, by year and fertilizers applied. The mean amount of biomass from cereal crops left on the field was 1,070.9 g m-2 DM, besides, 906.7 g m-2 of that was made up of above-ground (AG) residues and 164.2 g m-2 of below-ground (BG) residues. On average, 471.8 g m-2 C and 14.3 g m-2 N were captured, including: 411.2 g m-2 C and 12.9 g m-2 N by AG residues; 60.7 g m-2 C and 1.4 g m-2 N by BG residues. Regularities between grain yield and residues were found, however, they were not very strong. The dataset should be enlarged to reduce uncertainty. As the data calculated from crop have a greater uncertainty, the GHG inventory should be calculated according to the average AG and BG biomass, which provide more accurate data

Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

SCREENING ASSAYS TO FIND OUT LATE LATENT SYPHILIS CASES - WHICH IS THE BEST ONE?

The serological methods for diagnosis of syphilis are classified into non-specific (non-treponemal) such as Rapid Plasma Reagin (RPR), and specific (treponemal) such as Treponema pallidum hemagglutination test (TPHA) and Enzyme-linked immunosorbent assay IgG, IgM (ELISA IgG, IgM) tests. The aim of this retrospective study was to estimate and compare the sensitivity and specificity of RPR, TPHA and Syphilis ELISA IgG, IgM. The study was conducted on 18 799 clinically healthy persons who had visited the Outpatient clinic of Ministry of the Interior Clinical Centre, Latvia during 2 years period from August 2006 to November 2007. Patients were screened to find out possible late latent syphilis cases by using RPR, TPHA and ELISA IgG, IgM assays. The results showed the highest sensitivity indices of ELISA IgG, IgM and TPHA methods, and the lowest for the RPR test. Highest specificity indices were observed by using ELISA IgG, IgM method followed by TPHA method with lower values and RPR method showing the lowest specificity. To conclude, ELISA IgG, IgM and TPHA methods should be used for screening late latent syphilis cases and ELISA IgG, IgM for diagnosis confirmation. RPR is not recommended for screening purposes