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Dynamic changes in reducing sugars in the process of starch hydrolyses
2001
Brence, E. (Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Food Technology. Dept. of Chemistry)
The content of reducing sugars can be 30% higher if modified amylase is added to scald. Investigations were carried out with the rye-flour and fine flour scald. Photometrical method was used as a standard method for the determination of reducing sugars. Enzymes were inactvated using the advanced method. Results show, that the amount of reducing sugars is 1.8% lower in rye-flour and 2.1% lower in fine flour compare to the results obtained using the standard method.
Afficher plus [+] Moins [-]Impact of polyploidization on the crude protein yield of tetraploid red clover varieties
2001
Tamm, S. | Bender, A. (Jogeva Plant Breeding Inst. (Estonia)) | Rausberg, P.
In plot trials, seeded in a pure stand without a cover crop, tetraploid red clover varieties bred at Jogeva - 'Varte' (early) and 'Ilte' (late), outyielded the diploid standard varieties in crude protein yield at optimal harvest schedule by 30.8% as an average of two production years (the yields 2255 and 1724 kg ha*[-1), respectively) and 14.9% (the yields 2073 and 1804 kg ha*[-1), respectively), by 26.3% as an average of three production years (the yields 2254 and 1785 kg ha*[-1), respectively) and 28.4% (the yields 2173 and 1693 kg ha*[-1), respectively). Considering the crude protein content of dry matter and crude protein yield, a three-cut harvesting regime should be applied in early tetraploid red clover varieties to attain the best result. Then the first cut should be taken at the budding stage, the second at early bloom of regrowth and the third cut prior to the commencement of night frosts. The late tetraploid red clover varieties should be harvested twice-the first cut at the budding stage and the second cut prior to the first night frosts. The larger crude protein yield of tetraploid varieties was caused mainly by their higher dry matter yield; it was affected to a lesser extent by the crude protein content of dry matter. Yet, the tetraploid varieties exceeded in majority of harvest times the diploid varieties in dry matter's crude protein content but the excess was mainly insignificant.
Afficher plus [+] Moins [-]Evaluation of the content of micro-organisms and somatic cells in the cow's milk
2001
Konosonoka, I.H. (Latvia Univ. of Agriculture, Sigulda (Latvia). Research Centre "Sigra")
Milk quality analyses were carried out at the Department of Veterinary Medicine of the LUA Research Centre "Sigra". The total amount of investigated samples was 140, of which 81.4% proved to be appropriate for extra and first class milk, but 18.6% were unqualitative. The total number of microorganisms ranged from 8000 to 20,000,000, but the number of somatic cells from 1000 to 4,068,000 in 1 ml of milk. Coagulase - positive Staphylococcus aureus were isolated in 8 cases or 5.7%. Coagulase - negative Staphylococcus were isolated in 31 cases or 22.1%. Using the BBL Crystal Indentification System for Gram-Positive microorganisms, four species of microorganisms Staphylococcus aureus, Staphylococcus intermedius, Micrococcus sedentarius and Micrococcus luteus were identified which are building various colonies on Baird-Parker Agar.
Afficher plus [+] Moins [-]Economical motivation of birch forest plantation
2001
Zudrags, M. (Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Forestry. Dept. of Silviculture)
More than 17,5% of Latvian agricultural land is abondoned, therefore effective use of this land is a significant issue in national economics. One of the alternatives of how to use abandoned agricultural land is its afforestation by birch. The present research is based on the Scandinavian experience. Calculations have been made on the necessary investments and management costs. The recovery and possible impact on price changes in raw birch materials are analysed as well.
Afficher plus [+] Moins [-][Problems of the hulless barley seed and grain quality]
2001
Legzdina, L. (Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Dept. of Plant Production)
Problems in hulless barley growing are caused by a low germination ability and emergence. Grain quality for feed and food are influenced by threshability and infection with fungal diseases. The aim of experiments was to investigate the possible hulless barley seed and grain quality problems under Latvia's conditions. Germination, emergence, test weight, 1000 grain weight and threshability of 77 hulless barley genotypes of diverse origin were determined and compared to hulled control varieties. Correlation between hulless barley germination, grain germ damage and grain infection with Fusarium, Helmintosporium and Penicillum was analyzed. The seed material structure (content of grains with damaged germ, broken grains and grains with undetached hulls) of 5 hulless barley genotypes was determined.
Afficher plus [+] Moins [-][Forecasting possibilities of potato late blight in Latvia]
2001
Bimsteine, G. (Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture. Dept. of Plant Biology and Protection)
Weather conditions in Latvia are very favourable for the development of potato late blight caused by Phytophthora infestans (Mont) de Bary. The control of potato late blight can be performed using different approaches: standardised technology, prognoses of the first infection and prognoses of the progress of disease development. The negative prognosis model Negfry is based on the last two mentioned above. For the control of potato late blight in Latvia mainly has been used - standardised technology. The first field treatment was made during the row closing or according to prognoses. Regular treatments were made each 8-14 days. The use of NegFry model started in Latvia in 1998. Local varieties and weather data have been used for the trial. For the control of potato late blight in field trials standartised fungicide application was compared with the NegFry model and the untreated variant. The major task of the use of the model is possibility to reduce the number of fungicide treatments. The NegFry model helps to realise an integrated plant protection system, which decreases fungicide application and increases economical efficiency.
Afficher plus [+] Moins [-][Investigation methods of the perception of urban landscape]
2001
Lomakins, A. (Latvia Univ. of Agriculture, Jelgava (Latvia). Dept. of Architecture and Building)
By using city of Jelgava and its separate districts as an example, the article investigates the practical applicability of some theoretic investigations related to the life in cities.
Afficher plus [+] Moins [-][Analysis of export and import of the most important building materials (1995-1999)]
2001
Gusta, S. (Riga Technical Univ. (Latvia). Production and Entrepreneurship Inst.)
The article deals with the current situation in production of building materials and foreign trade in Latvia. Export and import of building materials are one of the most important factors influencing the production of building materials. The report analyses import and export development trends within two sections of the harmonized system: wood and articles of wood; the articles of stone, plaster, glassware and ceramics.
Afficher plus [+] Moins [-]Comparison of energy and protein content in different grasses during the vegetation
2001
Beca, M. (Latvia Univ. of Agriculture, Sigulda (Latvia). Research Centre "Sigra")
The quality of forage grass mostly depends on the harvesting time. In early vegetation stages, grasses have a high protein and energy content and high dry matter digestibility. The data on the protein content and energy value of different grasses gives a possibility to choose the best conservation method. Changes in the chemical composition of perennial grasses during the vegetation were investigated at the Laboratory of Biochemistry of the LUA Research Centre "Sigra". The dynamics of the content of amino acids was evaluated.
Afficher plus [+] Moins [-]The role of science and education at the millenium in Latvia and Europe
2001
Lescevica, M. (Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Economics. Dept. of Economics)
During the last decade economy of Latvia has experienced a decrease, crises and also depression. Further development process of Latvia could lead to a rapid economical boom. The application of scientific researches into the development of nationaly economy of Latvia is one of the important aspects. Though the globalisation and commercalisation of scientific researches must be taken into account as well. Science development is opening wide range of possibilitities for research perfection. Most of the Latvian, Lithuanian and Slovakian entrepreneurs are 30-40 years old, who suddenly appeared in the circumstances of conventionally free economy in their twenties.
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