خيارات البحث
النتائج 1361 - 1370 من 2,106
The effect of double inoculation on the broad beans (Vicia faba L.) yield quality النص الكامل
2015
Dubova, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Senberga, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Legumes (Leguminosae) are one of the most widely grown crops in the world after cereals (Poaceae). They are not only an important source of protein in food and feed, but also a significant component of different agrosystems. The N2 fixation by legumes is of great importance in nutrient management and sustainable economy of nitrogen. Legume productivity largely depends on a successful formation of symbiosis between the plant and soil microorganisms. The most important among those are rhizobia and mycorrhiza fungi. The field experiment was carried out at the Institute of Soil and Plant Sciences, Latvia University of Agriculture in 2014 to evaluate the influence of double inoculation using rhizobium leguminosarum and mycorrhiza fungi preparation on yield formation of broad bean V. faba L. var. major Harz ‘Bartek’. The bean seeds were treated with rhizobia and/or mycorrhiza fungi before sowing. Seeds were treated with rhizobia by soaking in bacteria suspension for 30 minutes directly before sowing. Mycorrhiza fungi preparation was added in soil under seeds before sowing. Plant height, fresh and dry weight and the weight of nodules were measured at the beginning of broad bean flowering (BBCH 60-61). rhizobium leguminosarum response to double inoculation differed between the strains. Rhizobium leguminosarum strain RL407, isolated from Vicia faba, was shown to be the most appropriate strain used for inoculation of broad bean seeds. Bean seed double inoculation increases the protein content significantly comparing to single inoculation using mycorrhiza fungi preparation.
اظهر المزيد [+] اقل [-]The changes in nitrogen content in soil depending on winter wheat (Triticum aestivum L.) fertilizing system النص الكامل
2015
Skudra, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian Rural Advisory and Training Centre, Ozolnieki parish, Ozolnieki Municipality (Latvia) | Ruza, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The objective of this study was to evaluate the main plant nutrient: mineral nitrogen (NH4 + -N and NO3 -N) dynamic in soil under fertilizing for obtaining high grain yields of winter wheat (Triticum aestivum L.) and to determine relationships between nutrient uptake and winter wheat productivity. The field study was carried out at the Research and Study farm ‘Vecauce’ of the Latvia University of Agriculture for two years 2012/2013 and 2013/2014 with winter wheat variety ‘Kranich’. Different nitrogen application rates (0, 85, 153, 150, 175, 180 and 187 kg haE-1) and timing were used for winter wheat. The content of nitrates NO3 -N and ammonium nitrogen NH4 -N was determined in the soil layers 0-0.20 m, 0.20-0.40 m, 0.40-0.60 m. Nitrogen management strategy during the plant growth period based on soil Nmin evaluating can improve N use efficiency and reduce environmental contamination. The maximum of mineral nitrogen content in soil in the vegetation period was observed at the beginning of stem elongation with a tendency to decrease. A significant impact (p is less than 0.05) of nitrogen fertilizer application was noted on the mineral nitrogen content in soil layer 0-0.20 m deep in both trial years. The increasing doses of nitrogen fertilizer raised the amount of mineral N in the soil profile. The significant impact (p is less than 0.001) of nitrogen application and year conditions was observed on grain yield. Close positive correlation significant at 99% probability level was observed between the grain protein content and nitrogen concentration mostly in all soil layers, but it was not found between the grain yield and nitrogen content.
اظهر المزيد [+] اقل [-]Light - emitting diodes (LEDs) for higher nutritional quality of brassicaceae microgreens النص الكامل
2015
Vastakaite, V., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania) | Virsile, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of this study was to investigate the effect of industrially designed light-emitting diode (LED) lamp lighting on the nutritional quality of Brassicaceae microgreens. Red pak choi (Brassica rapa var. chinensis ‘Rubi F1 ’), tatsoi (Brassica rapa var. rosularis) and mustard (Brassica juncea L. ‘Red Lion’) were grown in a greenhouse (20±2/18±2 °C) during winter season, and the solar daily integral (DLI) was ~3.46±1.16 mol mE-2 dE-1. The light spectra of lamp consist of 8 violet (420-430), 16 blue (460-470 nm), 8 orange (610-615 nm), 3 red (620-630 nm), 56 red (660-670 nm), 8 white (contain blue (400-500 nm), green (500-600 nm) and red (600-700 nm)) LEDs. The treatments of ~150 and ~250 µmol m-2 sE-1 LED irradiance levels (LED 150 and LED 250) for 16 h dE-1 in comparison with high pressure sodium (HPS) lamps (~150 µmol mE-2 sE-1) as a control were performed. Photophysiological response to the artificial light varied among Brassicaceae species. Microgreens treated with LED 150 and LED 250 were significantly (P is less than or equal to 0.05) shorter and formed smaller hypocotyls. The photooxidative changes were evoked by both lighting treatments and led to higher phytochemical (phenols, ascorbic acid, flavonols, anthocyanins) and mineral element (Ca, K, Mg, Na, P, Fe, Zn) contents, and the DPPH and ABTS free radicals scavenging activities in all microgreens. Significantly lower content of nitrate was obtained with LED 150 treatment. Finally, LED lamps have the potential to be used as the main light source for growing high nutritional quality microgreens in greenhouses.
اظهر المزيد [+] اقل [-]The effect of growing systems on the quality of carrots النص الكامل
2015
Bender, I., Estonian Crop Research Inst., Jogeva, Jogeva parish (Estonia) | Moor, U., Estonian Univ. of Life Sciences, Tartu (Estonia) | Luik, A., Estonian Univ. of Life Sciences, Tartu (Estonia)
The aim of the research was to evaluate how the quality of carrots is affected by organic and conventional production systems. The experiment was carried out at the Estonian Crop Research Institute in 2009. Conventional treatment received the following amount of nutrients via mineral fertilizers: N 115, P 40 and K 152 kg haE-1. For plant protection, the following pesticides were used: Fenix, Fastac 50, Agil and Signum. In organic cultivation system compost and humic acid solution Humistar were used for fertilization and polypropylene non-woven fabric Agryl P-17 for plant protection. Marketable yield of organic carrots was 8% lower compared to the conventional carrots. Conventional carrots contained pesticide residues and had significantly higher nitrate concentration than organic carrots. The contents of total sugars, phosphorus, potassium, calcium and magnesium did not differ significantly between carrots from different cultivation systems. At harvest, dry matter (DM) content of organically grown carrots was significantly higher, whereas vitamin C and ß-carotene content was significantly lower in organically grown carrots. However, after 5-months of storage, the organic carrots had significantly higher total soluble solids (TSS) and β-carotene content compared to the conventional ones indicating that organically grown carrots were less susceptible to storage conditions.
اظهر المزيد [+] اقل [-]Diversity of lactic acid bacteria in raw milk النص الكامل
2015
Bluma, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ciprovica, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
In this study we described the diversity of lactic acid bacteria and their representatives in raw and thermally treated milk, focusing on their potential in cheese production influencing cheese quality. The aim of the present study was to analyse the concentrations and representatives of lactic acid bacteria in raw milk and to detect the changes of lactic acid bacteria microflora during thermal treatment of cheese milk at a dairy processing plant. The analysis carried out in the study showed a seasonal variation in the microbial composition and quantity of raw milk. The most frequently isolated lactic acid bacteria: lactococci, lactobacilli, leuconostoc were found at low level in raw milk (mean 9.27×103 CFU mLE-1) and the most frequently identified species were Lactococcus lactis, Lactobacillus brevis and Lactobacillus fermentum. The microflora of raw and pasteurised milk is similar to the analysed lactic acid bacteria representatives in the samples. Interestingly, we found the same species in raw milk and pasteurised milk, for example, Lactobacillus brevis and Lactobacillus fermentum were detected in the same samples in raw milk and pasteurised milk. Our study showed that lactic acid bacteria concentration was quite low in pasteurised milk (0-76 CFU mLE-1), but they grow rapidly in cheese during ripening; therefore the definition of limits of the non–starter lactic acid bacteria colony forming units in milk should be reasonable for selection of appropriate raw milk quality for cheesemaking.
اظهر المزيد [+] اقل [-]Probiotic and prebiotic influence on haematological values of goat kids النص الكامل
2015
Otzule, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ilgaza, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Blood haematology is one of the indicators that shows if a goat (Capra hircus) kid gets a sufficient quantity of liquid, has a good supply of oxygen in the body, as well as an indication of inflammatory processes. Our aim of this research was to find out how feed additives (probiotics (Enterococcus faecium), prebiotics (Jerusalem artichoke (Helianthus tuberosus L.)) and symbiotics (Enterococcus faecium+ Jerusalem artichoke)) influence on haematological parameters of kids. Research was performed in Latvia in 2014. The blood samples were analyzed for leucocytes (WBC), erythrocyte number (RBC), haemoglobin (HGB) concentration, packed cell volume (HCT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentrations (MCHC). Since the blood indicators have not significantly changed in all examination times, we analyzed the results of the age of 4, 8 and 12 weeks. HCT downward trend in blood sample MRG + PRO, MRG + PRE and MRG + SIM group of kids was observed from the fourth week up to the eighth week and then it gradually increased. The results showed that the HCT, HGB, RBC, MCHC and WBC number was comparable (p is greater than 0.05) between groups. Our results prove that the use of Jerusalem artichoke powder as an additive to food not only improves digestion and metabolism of ruminant, but also helps to maintain constant haematological values. In the control group and the kids who received probiotics, prebiotics or symbiotics - significant differences are evident in all haematological parameters (p is less than 0.05) at the age of 12 weeks.
اظهر المزيد [+] اقل [-]Corticosteroid-induced hepatopathy in dogs النص الكامل
2015
Kondratjeva, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Birgele, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
Corticosteroid therapy is often used on dogs (Canis lupus familiaris) to treat different kinds of diseases. One of the most common complications of corticosteroid use is steroid hepatopathy, a specific pathology only in dogs. The objective of this study was to determine whether and how significant the liver functional changes after one administration of different kinds of corticosteroids in standard dosages are. The study took place in private veterinary clinics in Riga, Latvia, during 2013 - 2014, with the permission of dogs’ owners. Twenty animals, which received corticosteroids due to present diagnosis, were divided into four groups. To reach the aim such corticosteroids as dexamethasone sodium phosphate, prednisolone acetate, methylprednisolone acetate and hydrocortisone aceponate were used in standard dosage one time to these dogs, respectively. Then, such blood serum enzymes as alaninaminotransferase (ALAT) and alkaline phosphatase (AP) were determined 24, 48 and 96 hours after the use of corticosteroids. It was discovered that the only one administration of dexamethasone sodium phosphate and methylprednisolone acetate in standard dosage can significantly increase (p is less than 0.05) ALAT and AP mean values in dogs. The corticosteroid prednisolone acetate was used once in standard dosage and hydrocortisone aceponate spray was used once and did not statistically significantly (p is greater than 0.05) change the values of alaninaminotransferase (ALAT) and alkaline phosphatase (AP) in dogs’ blood serum during this study.
اظهر المزيد [+] اقل [-]Morphological changes in artificially reared one year old sea trout (Salmo trutta L.) during spring النص الكامل
2015
Rutkovska, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Medne, R., Institute of Food Safety, Animal Health and Environment BIOR, Riga (Latvia)
Morphological parameters and their changes common for artificially reared one year old sea trout were examined from January to May the year 2013 to determine whether these parameters indicated the smoltification in one year old sea trout and whether these fish achieved smolts stage. Fish were reared in flow-through and recirculation systems in hatcheries based on three different rivers (Brasla, Daugava, Venta basin). Sea trout were examined in the Latvia University of Agriculture, Faculty of Veterinary Medicine, Institute of Food and Environmental Hygiene and in the Institute of Food Safety, Animal Health and Environment BIOR, Laboratory of Aquaculture and Fish Pathology. To appreciate fish growth stage condition index, hepatosomatic index, spleen index was calculated and silvering level was evaluated. The fish condition index decreased in all hatcheries and flow-through and recirculation rearing systems from January to April and increased in May. Spleen index was the most stable parameter and did not change a lot showing that fish did not have migratory stress in April and May. Silvering level increased from January to April but suddenly the increase became slower in May without reaching the top level. These results made us to consider that one year old sea trout parrs released in May 2013 probably did not become smolts before release and they had to stay in river for one additional year until reaching pronounced smolt stage.
اظهر المزيد [+] اقل [-]Land consolidation in Slovakia, where it hangs? النص الكامل
2015
Bazík, J., Slovak Univ. of Agriculture in Nitra (Slovak Republic) | Muchova, Z., Slovak Univ. of Agriculture in Nitra (Slovak Republic)
Land consolidations in Slovakia are regarded as an instrument for solution of ownership fragmentation in accordance to rural development. In the introduction of this paper, we describe problems in Slovakia associated with the ownership fragmentation. Country, rural areas were significantly influenced by the period of collectivization. The benefits of land consolidation project are shown in a case study area for Kanianka cadastre. We compare ownership relations before and after the land consolidation. Statistical values as number of resolved ownerships by LC, number of plots and average size of plots are shown. New infrastructure, water management and ecological elements are discussed. In conclusion, we give the reason why activities related to land consolidation in Slovakia stagnates despite positive response.
اظهر المزيد [+] اقل [-]Temperature protection methods of induction motor النص الكامل
2015
Gedzurs, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
In conditions where induction motors are frequently started, overloaded and used in high inertia applications with long starting times, supplied from frequency converter, a temperature protection system are more reliable to protect induction motor stator winding against thermal overloads. There are different types of temperature protections - thermostat, PTC thermistor, resistance temperature detector (RTD) and thermocouples, so it is important to know the properties of each type to choose an adequate protection system. Analyses of temperature sensor properties and their advantages and disadvantages show, that PTC thermistor is a cost-effective temperature protection solution, but for medium and high voltage induction motor protection RTD are commonly used. A virtual model has been represented to simulate the temperature sensor thermal time constant under different thermal conductivity and thickness of winding magnet wire insulation.
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