2021, Vol. 19, No. 4
Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/7135
Sirvi
Sirvi 2021, Vol. 19, No. 4 Kuupäev järgi
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Kirje Digestate application with regard to greenhouse gases and physical soil properties(2021) Šařec, P.; Korba, J.; Novák, V.; Křížová, K.The article deals with the method of application of digestate with regard to the environment, soil properties and utilization of nutrients by plants. The aim is to monitor the dependence of the emission gas leakage and the dose of applied fertilizer. With the current expansion of biogas plants, a large amount of waste product, especially digestate, is being generated. This product is most often used as a liquid organic fertilizer because it contains substances important for plant growth. The disadvantage of this fertilizer is the release of greenhouse gases into the air. The digestate contains mainly ammonia, nitrogen in the residual organic matter and is a fertilizer with rapidly releasing nitrogen. The ammonium nitrogen contained in the digestate is easily subject to air losses. Therefore, a method of application for a certain crop is sought, where the smallest leaks of gases into the air occur. Different amounts of doses for the same route of administration are compared. To measure the amount of emission gases, a wind tunnel was placed on each variant of the application, taking air above the soil surface, which is discharged to the gas analyser. The monitored greenhouse gases are CH4, NH3 and CO2. Furthermore, physical properties of soil were monitored in order to verify the conditions of the experiment. One of the parameters measured was the soil bulk density of the soil by taking intact soil samples. The penetration resistance of the soil was also determined, which indicates the degree of compaction. The use of nutrients was assessed through the condition of the stand on each variant by monitoring vegetation indices using remote sensing of the earth.Kirje The effect of cultivation technology on the plant development of organically grown garlic(2021) Lepse, L.; Zeipiņa, S.; Missa, I.; Osvalde, A.The new technological solutions for the hardneck garlic production were tested to prevent the influence of unfavourable soil and climatic conditions on the rooting, sprouting and wintering ability of hardneck garlic - factors that affect significantly the hardneck garlic production in Latvia. Field studies were carried out at the experimental field of the organic farm, located at the Koknese district, Latvia, during the seasons of 2018/2019 and 2019/2020, on sandy loam soil using hardneck garlic cultivar `Liubasha` and local clones. Two variants of garlic growing were compared - traditional planting in the autumn in the field as control, and planting in the trays as an innovative solution. Results indicated that low temperature treatment (below +7 °C) for the period of at least 50 days initiates cloves primordia development. The using of trays is effective technology to prevent unfavourable agroecological conditions on the field in the case if controlled conditions are available and technically feasible in the farm.Kirje Hybridspecific nutrient interactions and their role in maize yield quality(Estonian University of Life Sciences, 2021) Bojtor, C.; Illés, Á.; Horváth, É.; Nagy, J.; Marton, L.C.Different fertilization levels can be used according to the intensity of the plant production technology. The interactions among all the essential nutrients, the different ways of antagonisms and synergisms can weaken or strengthen the physiological processes of the plants, affecting significantly the efficiency of the production. Complex mineral profile of the vegetative (stalk, leaves) at V2, V4, V8, VT and R6 stages in 4 replications and generative (grain, cob -R6 stage only) plant parts of maize were determined in accredited laboratory with ICP-MS, ICP-OES microwave-assisted multielement analysis for metal components (P, K, mg, Ca, S, Zn, Fe, Cu, Mn, Ni, Mo) and Dumas method for nitrogen. Results showed that the effect of different nitrogen fertilization levels was significant on grain yield, protein, oil and moisture content. Significant differences were measured between the different maize genotypes in grain yield, protein and starch content. In the experiment all essential nutrient concentrations were measured, and the important nutrient ratios of macro- and micronutrients for the physiological development of maize were calculated. These nutrient stoichiometric ratios were evaluated according to their scale of influence in the yield formation. It can be concluded that different nitrogen fertilization levels affected significantly the essential nutrient ratios of the vegetative and generative plant parts of three maize hybrids in the growth period. Although different variables of nutrient stoichiometric ratios and yield parameters did not highly correlated, Pearson’s correlations suggest that K:Mg and K:Zn ratio of stalk would be related with grain yield (R = 0.32; 0.34; 0.39 and 0.35; 0.37; 0.30, respectively) marking them as important parameters for novel nutrient stoichiometry research. Analysing the optimal nutrient ratios related to the yield quality and their interaction with the fertilization practices can give certain recommendations to the farmers to implement hybrid- and site-specific nutrient management strategies, reducing the environmental impact of the over-fertilization.Kirje Leaf nutrient status of tomatoes in coconut coir medium – differences in cultivars, impact on yield and quality(2021) Osvalde, A.; Karlsons, A.; Cekstere, G.Coconut coir as an alternative to rockwool is increasingly used as a substrate for soilless hydroponic greenhouse production of tomatoes. However, little is known about the nutrient status of tomatoes in coconut coir, especially under intensive production conditions. The aim of this study was to investigate the nutrient status of different tomato cultivars (orange plum ‘Organza F1’, red cherry ‘Daltary RZ F1’, red large fruit-sized ‘Securitas RZ F1’ and pink large fruit-sized ‘Fujimaru F1’) under industrial greenhouse production, using coconut coir as a substrate to reveal nutrient imbalances, their impact on tomato yield and quality, and cultivar differences. Essential nutrient and leaf SPAD value was detected for the youngest fully developed leaves and the old still vital leaves twice per month from April to August 2020. The total yield, marketable and non-marketable yield was regularly determined. During the crop cycle, the content of most of the nutrients in tomato leaves corresponded to the standard range reported for tomatoes. Only some imbalances were found: all cultivars were characterized by low Zn and high S levels in both young and old leaves. The obtained results identified several differences between the cultivars: cherry tomatoes 'Daltary' had significantly higher N, K, Fe and Zn in leaves compared to other cultivars. The lowest N, Fe and Cu were determined for large fruit-sized ‘Securitas’. Regardless of the nutrient status and microclimate conditions, the marketable yield of ‘Daltary’, ‘Organza’ and ‘Securitas’ was almost 100%, indicating on high suitability of these cultivars for hydroponic cultivation in coconut coir.Kirje Community/shared solar power option: a pathway to sustainable rural electrification in Nigeria(Estonian University of Life Sciences, 2021) Dunmade, I.Nigerian governments at all levels have been making concerted effort to extend electricity supply to the rural areas. Among the several efforts by various governments are formulation of rural electrification policies, creation of agencies for the administration of rural electrification projects, installation of diesel power generators, and development of public-private partnership strategies in solving rural power supply problems. While significant progress has been made, several rural communities are yet to have access to electricity supply. Rugged terrain and limited financial resources are among the constraints to extension off-grid to the rural areas. However, electricity supply, being one of the drivers of economic development and social wellbeing, is a problem that has to be tackled head-on. The current climate change concern and many other environmental issues of our time necessitate finding a sustainable solution to the problem. Consequently the goal of this study was to examine the potentials of community solar power option as a sustainable rural electrification approach in Nigeria. Other goals included identifying potential hick-ups and solutions to lifecycle management of community solar. Moreover, the study was to determine the suitable configuration for efficient and sustainable community solar power management in Nigeria. The study methodology involved intensive literature survey, historical data collection and case studies on rural electrification in Nigeria as well as examples of community solar projects in Nigeria. Preliminary results revealed that community solar power would be a sustainable approach to rural electrification in Nigeria if a number of conditions are satisfied. Some of the conditions to be satisfied include devolving the management of a community solar system to a participative committee of stakeholders representatives, and incorporating community capacity building in the plan. Other conditions are government, corporate and municipalities’ collaboration in funding such projects from scratch till after one or two years of operation, and incorporation of monitoring and intervention strategies for continuous power supply and further improvement.Kirje Decision three to predict respiratory rate of piglets submitted to cold conditions(Estonian University of Life Sciences, 2021) Ferraz, P.F.P.; Cadavid, V.G.; Ferraz, G.A.S.; Saraz, J.A.O.; Rossi, G.; Barbari, M.Pigs subjected to thermal conditions outside their comfort zones may show altered physiological and behavioural responses, which may consequently cause productive losses. For these reasons, the aim of this paper is to develop a decision tree for the prediction of respiratory rate (RR, mov min-1 ) of piglets exposed to different thermal situations. The experiment was carried out in an experimental pig farm of the Universidad Nacional de Colombia Campus Medellin, located at the San Pablo Agraria Experimental Station located in the eastern sector of the department of Antioquia, during August 2019. A database containing the raw data for dry bulb temperature - tdb (°C), and relative humidity - RH (%) as input variables, and RR (mov min-1 ) of six piglets were assessed every two hours as output variable for piglets was generated. The experimental database was composed of 78 observed data. The decision trees were developed to conditions of tdb between 19.2 to 29.5 °C and RH between 50.2 to 88.4%. In the experimental period, RR of piglets submitted to tdb higher than 27.1 °C the RR was around 60 mov min-1 , tdb smaller than 27.1 °C the RR varied from 36 to 46 mov min-1 . These low values of physiological responses may indicate that the piglets are not in a comfortable situation, so their development, welfare and production can be affected. The decision tree developed can be useful to provide a quick understanding of the piglet’s welfare condition based on the environmental variables and physiological responses.Kirje Responses of onion growth and yield to different planting dates and land management practices(Estonian University of Life Sciences, 2021) Salari, H.; Antil, R.S.; Saharawat, Y.S.Local varieties of onion (Allium cepa L.) are believed to be well adopted to agroecological conditions of their respective growing region but their lower productivity is a concern to be addressed. The variety ‘Safid e Paisaye’ was selected for this investigation due to its long storability and higher market demand. The present study was carried out at Agriculture Research Farm of Kabul University to study the influence of land management practices and planting dates on growth and yield of onion. Different agronomic traits including number of leaves per plant, leaf length, leaf area per plant, leaf area index, normalized difference vegetation index (NDVI), maturity period, marketable yield and total yield were studied in these trials. The recorded data were statistically analysed with R software. The planting dates had significant influence on growth and yield of onions. At 90 days after sowing, the highest number of leaves per plant (7.18), leaf length (30.07 cm), leaf area per plant (277.43 cm2 ), leaf area index (0.93) and NDVI (0.29) were recorded for the first planting date (10th May). Similarly, the longest maturity period (176.44 days) and highest marketable yield (37.01 t ha-1 ) and total yield (40.08 t ha-1 ) were also observed under the first planting date. Land management practices did not have significant effect on growth and maturity period of onions. However, the marketable yield was influenced by tillage depth and land preparation. The deep tillage and flatbed recorded highest marketable yield of 38.58 t ha-1 and 26.9 t ha-1 , respectively. The results of the study indicate that, early planting was more appropriate to get vigorous and high yielding onions. The deep ploughed flatbeds were appropriate to get higher marketable yield of onions.Kirje Biomass ash as a potential raw material for the production of mineral fertilisers(Estonian University of Life Sciences, 2021) Stankowski, S.; Chajduk, E.; Osińska, B.; Gibczyńska, M.Ash obtained from biomass combustion could be a valuable product for fertilisation of soil or/and plant. It is connected with high reaction and potassium, calcium, magnesium content as well as low content of heavy metals. The analysed phyto-ash was obtained from Szczecin Power Plant Poland (12.2018–12.2019). The samples of phyto-ash, in the number of 24, were collected on subsequent dates at two-week intervals to determine the total content of the analysed elements (P, K, Mg, Ca, As, Cd, Ni, Cr, Pb, Hg). The differentiated percentage share of macroelements both in total form as well as available form in ash from wood biomass and Agro-biomass is described as: calcium > potassium > magnesium > phosphorus. Phosphorus is characterised by a very low (10%) and highly variable availability. Ash from biomass is characterised by alkali pH (13.0). Biomass ash can be treated as a mineral fertiliser used for soil deacidification and as a substitute for calcium fertilisers. Biomass ash has a high content of potassium and magnesium, which could qualify this by-product as a source for fertiliser. Mean contents of heavy metals: lead, cadmium, arsenic and mercury in ash do not exceed the limit values for the mineral fertilisers. The variable percentage share of Agro-biomass did not result in significant changes in the amount of available form of macro-elements in ash. The obtained results indicate the pronounced variability, depending on the season in a year, of the content of available macroelements in biomass ash.Kirje DEM modelling of tillage tools in sand and verification of draft forces in the soil box(Estonian University of Life Sciences, 2021) Kuře, J.; Linda, M.; Chotěborský, R.; Černilová, B.; Hromasová, M.Soil resistance is still being important parameter during tillage. By reducing the soil resistance during processing, greater efficiency and cost reduction can be achieved. With the correct design of the shape of the tillage tools, reduction in the force required for tillage can be achieved. New tool designs must be tested in field conditions to determine the effect. Using DEM (Discrete element method) modelling, individual designs can be compared without the need for field tests. However, the accuracy of the model must first be verified on real tests. The paper deals with the creation of a mathematical model of sand, which is used for testing tillage tools in the soil box. The models are focused on tests of various shapes of wings on tillage tools. Draft forces are compared, and the correctness of the model is verified.Kirje Influence of the structural and functional characteristics of the seeding material on the yield structure elements and resistance to leaf diseases of spring soft wheat(Estonian University of Life Sciences, 2021) Kolesnikov, L.E.; Priyatkin, N.S.; Arkhipov, M.V.; Razumova, I.E.; Radishevskiy, D.Yu.; Kolesnikova, Yu.R.The high-quality grain use when sowing is a necessary condition for obtaining a high yield. Along with the standard tests regulated by the ISTA (International Seed Testing Association), there are promising introscopic techniques for the seed material quality controlling - methods of microfocus radiography and gas discharge visualization (electrophotography). The effect of structural and functional characteristics of the seeding material on the wheat productivity and diseases resistance was studied out on the experimental field of the Vavilov All-Russian Institute of Plant Genetic Resources. Ten accessions of soft wheat with the ‘parametric passport’ (including more than thirty optical parameters, including gas discharge images, morpho- and densitometric analysis of X-ray patterns) were used as an experimental seeding material. Unviable wheat seeds, in comparison with healthy ones, were characterized mainly by a smaller area, form coefficient, standard deviation of three-dimensional fractality by isoline, entropy by isoline, higher brightness and standard deviation of the isoline radius of the gas discharge images. Morpho- and densitometric indices of unviable seeds differed in reduced values of the circle factor, roundness, minimum and maximum average brightness, but in greater elongation and optical density of the X-ray patterns projection. The intensity of wheat affection by diseases has varied depending on the structural and functional characteristics of seeds. It was noted, that the brown rust development decreased with an increase in the entropy by isoline, the contour irregularity and the average radius of the isoline.Kirje Evaluation of the combining ability of CMS lines in crosses with samples of grain sorghum and Sudan grass(2021) Kibalnik, O.; Kukoleva, S.; Semin, D.; Efremova, I.; Starchak, V.The versatility of use, species diversity, and high drought resistance have ensured the demand for sorghum among agricultural crops in the world. Currently, the most promising direction of breeding is the creation of F1 sorghum hybrids, which is based on the identification and selection of parental forms with high combining ability. In this paper, the combining ability analysis crosses of two hybridization schemes: grain×grain sorghum and grain sorghum×Sudan grass was carried out using topcross method. Gene action governing inheritance of a particular trait can be measured in terms of general and specific combining ability estimates, where general combining ability effects are mostly indicative of additive gene action (ms (GCA)/ms (SCA)>1)and specific combining ability effects - non-additive (ms (GCA)/ms (SCA)<1). Genes with an additive effect participate in the genetic control of breeding-valuable traits, which is proven byms(GCA)/ms (SCA) ratios changing within1.10-28.01 range. It is advisable to involve CMS-lines A3 Feterita 14, A2 KVV 114 and A2 O-1237 to create high-yielding hybrids of grain sorghum; highly productive sorghum-sudangrasshybridss - lines L-106, L-143 and Anastasiya, Kinelskaya 100, Elegiya variety samples; with a high share of grain in the total biomass – Allegoriya, Krasnodarskaya 75 and Zonalskaya 6 variety samples. CMS lines are distinguished by high and average CA values both in crosses with samples of grain sorghum and Sudan grass: by weight of 1,000 grains - A2 O-1237; by seed yield and weight of 1,000 grains - A2 KVV 114.Kirje The effect of bean flour addition on the rheological properties and baking quality of a triticale flour blends(Estonian University of Life Sciences, 2021) Maradudin, M.; Simakova, I.; Fedonnikov, A.The aim of this research work was to study and compare the main parameters of the rheological state of the dough made from triticale flour (a variety of George selection by the FSBIS Agricultural Research Institute of the South-East), dough made from flour of white and red bean seeds, as well as parameters of dough from flour of composite mixtures based on them. The rheological properties of the dough were determined using a Mixolab device according to the GOST ISO 17718-2015 method. The mixing ability of the blends was additionally tested by the SDS sedimentation method. It was found that the moment of force, which characterizes the gelatinization process, correlates well with the SDS sedimentation index. To a lesser extent, this indicator correlates with the values of the moments of force characterizing the process of ‘starch retrogradation’ and the energy intensity of the dough formation process. The water absorption capacity of flour highly correlates with the moment of force during the liquefaction phase and with the moments of force characterizing the minimum and maximum consistency of the dough during the ‘starch retrogradation’ phase. The correlation between the SDS sedimentation rate and water absorption capacity was found to be rather low. The rheological parameters were also significantly influenced by the type of beans. Taking into account the results of studies of the rheological state of the dough, test baking of bread with various mass fractions of components was carried out. The results obtained confirmed the improving effect of bean flour.Kirje Effect of replacement of coated barley grain with hulless barley in diet on growth, carcass and meat quality traits of fattening pigs(2021) Degola, L.; Jansons, I.; Šterna, V.A amount of experimental pigs were 40 crossbred pigs (Yorkshire × Landrace). The initial body weight of pigs were average 27.0 kg. The goal of research was to assess the effect of replacement of coated barley grain with hulless barley in diet on pig growth, carcass and pork quality indices. Experimental groups of pigs on the holding were conducted according to age and sex. For trial group of pigs, a compound feed with hulless barley (38.9–45.4%) was prepared, for the control with coated barley (39.3–43.3%). The feed recipes made according the pigs age. The other feed ingredients were not changed and were wheat, soybean meal and oil, premivit, and from 20 till 70 kg liveweight also fish meal. Diets were formulated with the same of metabolizable energy and crude protein content. During the study the live weight of pigs was monitored and the feed consumption was counted. At the end of the study all pigs slaughtered, determined carcasses traits and took samples of loin muscle for chemical analyses. The results showed that pig fattening indices (daily liveweight gain were in control pig group 0.686 ± 0.183 and trial 0.716 ± 0.174) did not differ significantly between groups (P > 0.05), although its were slightly lower in the control group pigs by 4.37%. Feed consumption for live weight gain in both groups ranged from 3.14 to 3.25 kg. Carcasses scores showed significant differences in lean meat and chops (P < 0.05). There were also differences in the backfat thickness. The thickness of backfat was 2.62 mm less in the control pig group, which indicates that when feeding coated barley to fattening pigs, the carcasses have a higher proportion of lean meat (62.1 ± 0.7%). Pigs were slaughtered reaching a live weight of 110 to 114 kg. The meat yield 71.7% and moisture level (70.2–75.2%), as well as protein (22.3–22.9%) indicators showed that fattening pigs are sold at the optimal age. In conclusion, results from this study suggest that feeding hulless barley to fattening pigs results in higher live weight gain. Carcass indicators showed a significantly higher proportion of lean meat and weight of chops when pigs eating coated barley. Chemical composition of pork in groups without significant differences.Kirje Enhanced assimilation rate due to seaweed biostimulant improves growth and yield of rice bean (Vigna umbellata)(2021) Pascual, P.R.L.; Carabio, D.E.; Abello, N.F.H.; Remedios, E.A.; Pascual, V.U.Rice beans are traditionally planted as intercrop to corn or as the main crop during dry season when corn production is difficult. The use of biostimulants is widely studied to ameliorate the adverse effects of biotic and abiotic stresses. Three possible fermented biostimulants: seaweed, bamboo shoot, and Japanese snail were compared to a commercial organic liquid fertilizer (10 mL L -1 ) based on morphological, photosynthetic, and yield responses. Fermented seaweed-treated rice bean registered the greatest average vapor pressure deficit (VPD) at 4.33 KPa on the first month and is comparable to the highest average VPD of 4.39 KPa registered by plants applied with fermented Japanese snail on the second month. This interestingly, did not result in difference of transpiration rate (µmol H2O m-2 s -1 ). Such could be attributed to the plants reduced stomatal aperture when applied with fermented seaweed at 406.80 µmol CO2 mol stomatal conductance and 38.59 Pa total conductance on the second month. Despite this, the average carbon dioxide assimilation rate of rice beans still increased in both the first (15.26 µmol CO2 m-2 s -1 ) and second (16.51 µmol CO2 m-2 s -1 ) month. This increased assimilation rate of fermented seaweed-treated rice beans resulted to about 12 cm increase in height at 128.53 cm (R 2 = 0.894), 0.02 g pod-1 (R 2 = 0.978) heavier and 0.90 seeds pod-1 (R 2 = 0.978) more when compared to those applied with the commercial liquid organic fertilizer. Thus, by limiting stomatal conductance, despite the differences in VPD, transpiration rate was not affected while significantly increasing assimilation rate to improve production of rice beans, thereby taking full advantage of available seaweed by-products.Kirje Assessment of essential oil yield in three mint species in the climatic conditions of Central Russia(2021) Shelepova, O.V.; Olekhnovich, L.S.; Konovalova, L.N.; Khusnetdinova, T.I.; Gulevich, A.A.; Baranova, E.N.The aim of the study was to study the harvest time for the essential oil yield and its qualitative composition in three species of mint Mentha piperita L. (Peppermint), M. spicata L. (Spearmint) and M. arvensis var. piperascens Malinv. ex. Holmes (Sakhalinmint). In 2018, the research was performed with plants of second year of vegetation in the Laboratory of Plant Physiology and Immunity of the NV Tsitsin Main Botanical Garden of the RAS. As a result, it was found that the optimal harvest period for Sakhalinmint and Peppermint should be recommended in a phase of mass flowering: the yield of fresh raw materials was 509–479 g m-2 , air-dry raw materials - 110–107 g m-2 ; the content of essential oil in the aboveground part (a mixture of leaves and inflorescences) of plants - 3.24–4.01%; the proportion of the main component of essential oil (menthol) - 57.3–50.2%. In Spearmint, the optimum time for harvesting is the phase of budding. The content of the main component of essential oil (carvon) was maximum - 67.9%, and the yield of essential oil was 2.6%, while the yield was 381 g m-2 of fresh raw materials (81.9 g m-2 of air-dry raw materials) at harvesting in this ontogenesis stage. Analysis of the secretory apparatus parameters on a surface of some green tissues in three mint species showed that the maximum density of secretory glands on both sides of the leaf is characteristic of peppermint, which provides a higher yield of essential oil in this type of mint. The study allowed determining the optimal harvesting time for highly productive mint species when they are grown in the conditions of Central Russia. The raw materials of these mint species can be used for the production of essential oils and are of interest for pharmacology and the perfume and cosmetics industry.Kirje Predicting farm performance: do indicators of farm economic viability and efficiency signify of probability of bankruptcy?(Estonian University of Life Sciences, 2021) Savickienė, J.; Miceikienė, A.Following the analysis of the indicators characterising the economic viability, efficiency and bankruptcy probability of farms proposed by researchers and employed in practice, the relationships between the indicators and their capacity to predict the prospects of farm activities as well to assess whether or not the indicators are indicative of the same patterns of farm activity, several different researchers' approaches have been identified. Certain researchers have been claiming that all of the indicators provide the same farm performance prospects, while others consider economic viability and efficiency to provide long-term farm performance prospects, while bankruptcy probability-negative profitability in the short term. The methods of convergent and discriminant validation employed allowed for analysis of the risk of potential overlap between the index of economic viability of a family farm and farm economic efficiency coefficient with the already available bankruptcy probability prediction models. For this purpose, categorical regression analysis was employed. This enabled the authors to determine that the index of economic viability of a family farm and coefficient of farm economic efficiency did not repeat the already available and used bankruptcy probability prediction models. Summarizing the results, it could be claimed that the index of economic viability of a family farm and coefficient of farm economic efficiency are not suitable as an alternative for assessment of the bankruptcy probability.Kirje Evaluation of morphological traits, genetic diversity and major resistance genes in barley subpopulations cultivated under organic and conventional farming systems(2021) Šķipars, V.; Ruņģis, D.; Ločmele, I.; Seile, S.; Mežaka, I.; Legzdiņa, L.Most crop varieties currently grown in organic conditions have been bred for conventional farming, and are not adapted to increased environmental variability under organic farming conditions and unpredictable environmental fluctuations due to climate change. This can be mitigated by the use of heterogeneous material, increasing genetic diversity and enabling adaptation to local conditions. The objective of this study was to determine the effects of several generations of cultivation in parallel under organic and conventional farming systems on the genetic diversity, morphological traits and frequency of major disease resistance genes as indicators of adaptation to the farming system in heterogeneous spring barley populations with differing levels of diversity. Populations in differing generations originating from crosses between two, three, 10 and 15 parental genotypes were cultivated in organic and conventional farming systems for three, four or 10 generations, thus forming subpopulations in each environment. These subpopulations were genotyped, and tested for morphological traits in both farming systems. A significant effect of cultivation environment on tillering capacity (p < 0.05) was found for all tested populations and in several cases for plant height, ear length and grain number per spike, indicating some adaptation trends. In the short term, genetic diversity parameters were not decreased in the later generation populations in comparison to the initial populations with the exception of observed heterozygosity, as expected for a self-pollinating species. No clear differences in genetic diversity parameters between populations cultivated under either organic or conventional condition for several generations were identified.Kirje Sowing time effect on yield and quality of field beans in a changing meteorological situation in the Baltic region(2021) Plūduma-Pauniņa, I.; Gaile, Z.; Bimšteine, G.As field beans (Vicia faba L.) need a lot of moisture to germinate, growers believe that they should be sown as early as possible in the spring. Field trial was carried out at the LLU RSF “Pēterlauki”, from 2018 to 2020. Following factors were researched: A) sowing time (early, medium and late), B) variety (‘Laura’, ‘Boxer’, ‘Isabell’), C) sowing rate (30, 40, 50 germinable seeds m-2 ), D) fungicide application (without and with application of fungicide at the GS 61-65). Meteorological conditions during the study had the greatest impact on the results as they were contrasting. Adverse meteorological conditions for field bean growing were observed in 2018 and in spring and early summer of 2019. The best year for bean yield formation was 2020, when temperature and precipitation was moderate. The highest average three year been yield was obtained sowing beans at the medium sowing time, however, equivalent yield was obtained sowing beans also in early sowing time. Fungicide application increased average three year yield significantly (p = 0.007) and independently of the sowing time. Influence of variety and sowing rate on average three year yield was insignificant, and it was not proved that any variety or sowing rate could be more suitable in a specific sowing time. Average three-year values of crude protein content, thousand seed weight and volume weight were affected by sowing time significantly (p < 0.001). Trial year, variety and fungicide application also affected all quality parameters significantly (p < 0.05), but the effect of sowing rate was insignificant (p > 0.05).Kirje Some features of cultivating different Chamaenerion angustifolium (L.) Scop. forms in vitro(Estonian University of Life Sciences, 2021) Egorova, D.A.; Molkanova, O.I.; Gorbunov, Yu.N.; Gulevich, A.A.; Baranova, E.N.Chamaenerion angustifolium (L.) Scop. characterized by a wide range of economically useful properties. White-flowered form of Ch. angustifolium (L.) Scop. Is extremely rare in nature. At the same time, it is promising as a source of biologically active substances and as a highly decorative plant. The optimal way to reproduce this form is clonal micropropagation. Methods for obtaining Ch. angustifolium in vitro were developed, as well as the optimal selection timing of starting material for micropropagation was determined. In addition, the effect of a mineral composition of nutrient medium and plant growth regulators on the regeneration of microshoots was studied. The highest values of morphometric parameters were achieved on MS medium (Murashige & Skoog, 1962) supplemented with 0.5 mg L-1 BAP. The multiplication factor of the lilac–flowered form was 8.4 ± 0.2, of the white-flowered form - 9.2 ± 0.6. Comparative analysis of morphometric parameters during cultivation of Ch. angustifolium showed no significant difference between the lilac-flowered and white-flowered forms. The effect of antioxidants on the growth and development of regenerants has been shown. The most optimal nutrient medium for clonal micropropagation of the lilac-flowered form was MS medium (Murashige & Skoog, 1962) containing 0.5 mg L-1 of BAP, 50 mg L-1 of ascorbic acid and 50 mg L-1 of citric acids and for micropropagation of the white–flowered form it was the medium, containing 100 mg L-1 PVP.Kirje Influence of mineral fertilizers on yielding capacity and quality of soft spring wheat grain(2021) Radchenko, M.V.; Trotsenko, V.I.; Hlupak, Z.I.; Zakharchenko, E.A.; Osmachko, O.M.; Moisiienko, V.V.; Panchуshуn, V.Z.; Stotska, S.V.The aim of the study is optimization of nutrition system for soft spring wheat plants through the use of mineral fertilizers in order to obtain high quality grain with simultaneous yield increase. Different doses of mineral fertilizers were tested in the study. The object of study was a variety of soft spring wheat ‘Uliublena’. The structure of the crop was determined by the method of selecting sheaf samples from each accounting area. The leaf surface area was determined by calculation method. According to the results of research, yield capacity of soft spring wheat on average ranged from 2.43 to 4.51 t ha-1 . The highest index of gluten amount was obtained in the variant with fertilizers dose N64P64K64 - 28.19%, which is higher than in the variants with fertilizer doses N16P16K16 and N32P32K32 by 6.11 and 0.15%. The highest increase in the yield of soft spring wheat grain (2.08 t ha-1 ) was obtained with application of N64P64K64, slightly lower yield increase was obtained with application of N32P32K32 - 1.64 t ha-1 , and N16P16K16 - 0.99 t ha-1 comparing with the control. With fertilizer dose of N64P64K64 soft spring wheat provided the maximum yield - 4.51 t ha-1 , gluten content - 28.19% and protein content - 14.21%.