2022, Vol. 20, No. 1

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/7698

Sirvi

Nüüd näidatakse 1 - 18 18

Utilization of Pachysolen tannophilus and Pichia kudriavzevii for the production of xylitol on undetoxified corn cob hydrolysates
(Estonian University of Life Sciences, 2022) Jolayemi, O.; Oke, M.A.; Rocha-Meneses, Lisandra; Omojasola, P.F.; Estonian University of Life Sciences. Institute of Forestry and Engineering. Chair of Biosystems Engineering
Xylitol is a natural polyol with broad applications in the food and pharmaceutical industries. However, its large-scale production through chemical means is still an expensive and not environmentally friendly process. Therefore, great attention has been paid to low-cost and renewable substrates like corn cobs (CC), which can be utilized to improve the economic outlook of xylitol production. In this study, CC were used as a feedstock for xylitol production, with the help of yeasts and filamentous fungi. The results obtained in this study showed that the amount of xylitol produced from CC hydrolysate was similar to the amount of xylitol obtained on xylose substrate. Overall, yeast produced higher amounts of xylitol than filamentous fungi. Pachysolen tannophilus had the highest xylitol production at pH 5.0, 72 h fermentation time, substrate concentration 15%, and inoculum size 1.5×108 cfu mL-1 , while Pichia kudriavzevii performed better at pH 5.0, with a 72 h fermentation time, substrate concentration of 20%, and inoculum size of 2.5×108 cfu mL-1 . When comparing the combined optimal parameters with and without supplementation, supplementation with 1.5% methanol, has increased the xylitol production of P. tannophilus and P. kudriavzevii by 31% and 18.6%, respectively. These findings demonstrate the robustness of these yeast strains for sustainable and cost-effective xylitol production from CC waste.
Opposite tendency between yield and taste of organic tomato by increasing biochar doses in a slightly humous arenosol
(Estonian University of Life Sciences, 2022) Kocsis, T.; Kotroczó, Z.; Juhos, K.; Ferschl, B.; Rozmann, V.; Brückner, A.; Biró, B.
The tomato is the edible berry of the plant Solanum lycopersicum. Tomato plants are widely grown in temperate climates worldwide and are mostly cultivated as annuals. The objective of this study was to understand the interrelation between fruit quality of tomato, some soil biological parameters, and the addition of increasing biochar (BC) soil amendment doses. BC is an industrial product, made from organic waste by pyrolysis. Its use in the soil is known to improve fertility and several soil functions. Among organic, ecological conditions, a field experiment was performed in a type of slightly humous arenosol soil. Effect of increasing doses of biochar (BC) (0.5-, 1.0-, 2.5-, 5.0, 10 m/m% and control) was studied. Nutrient content and Total Soluble Solid (TSS) of the fruits, the ripeness, and the marketable/non-marketable ratio of yield were assessed. The presence of some cultivable microbial physiological groups (fungi, bacteria) and the soil-dehydrogenase activity (DHA) was estimated. Results represented that the changes of fruit TSS content was not linear with the increasing doses of BC. The increased yield (+53%) had an inverse correlation with the TSS content of the berry's pulps, and the content was lowest at the highest BC dose. Optimum doses of BC were considered, like 1–2.5 m/m%, supported by the nutritive element content (+55% N, +76% P, +83% K) and enhanced microbial activities (+45% DHA). Grouping the parameters by Pearson Correlation Coefficient, the biochar amendment was a driving factor for tomato growth, with certain dose limits in the studied organic agricultural practice.
Nutritious lentil and rice meal for sustainable vegan and pescatarian diet
(Estonian University of Life Sciences, 2022) Lignicka, I.; Graci (Balgalve), A.; Zīdere-Laizāne, A.M.
Urbanization has been accompanied by changes towards diets that have placed increased pressure on the environment and human health. Shifting diet from beef towards lessimpactful proteins is the most important policy goal for dietary sustainability in 2050. Fish can also help to shift to lower emission diets, fish-eaters have nearly the same emissions profile as strict vegetarians. The aim of this study was to develop quick preparation lentil and rice meals that would be suitable for a sustainable vegan and pescatarian diet and to analyse and compare their nutritional values. Sample nutritional values were calculated according to raw material nutritional values. Results show that if most raw materials are plant-based there is no significant difference between vegan and pescatarian quick preparation meal sample nutritional values other than minerals and vitamins. Vegan quick preparation meal sample which contains green lentils has higher iron content comparing to pescatarian quick preparation meal which contains red lentils and freeze-dried salmon powder and has higher vitamin B1, B3 and B6 content.
Mechanical weed control strategies for grain amaranth (Amaranthus cruentus L.)
(Estonian University of Life Sciences, 2022) Casini, P.; Biancofiore, G.; Palchetti, E.
Currently, no herbicide is registered for grain amaranth in Europe, the United States and South America. Hence, weed control must be addressed with alternative methods. Field trials were conducted in 2018 and 2019 in Central Italy by comparing some mechanical weed control treatments in grain amaranth (Amaranthus cruentus L.). In 2018, the five treatments were: untreated control (T118), cutter hoeing (T218), flat share cuts and one central duck foot tine (T318), flat share cuts and two central duck foot tines (T418), and three duck foot tines (T518). In 2019, the five treatments were: untreated control (T119), three duck foot tines (T219), flex tine harrowing (T319), flex tine harrowing plus finger weeding with red fingers (T419), and finger weeding with red fingers (T520). In 2018, amaranth was a successful competitor against weeds from 40 days after emergence (10 true leaf stage, corresponding to BBCH code 15). The competitive ability was showed by excellent seed yields averaging 1.2 t ha-1 , for all treatments. This feature was also confirmed to some degree in 2019. However, seed yield in 2019 was more strongly influenced by treatment as well as by the lower emergence of plants. All the mechanical methods employed can be effectively used for weed control in grain amaranth. Treatments with the flex tine harrower and finger weeder negatively affected the plant density at harvest, necessitating further optimization. However, combined mechanical strategies proved the most effective, especially in controlling dicot weeds. There is a need to optimize strategies, with mechanical equipment, to anticipate and improve the ground cover of amaranth. These strategies include selecting optimal plant density and the correct distancing between the rows for easier mechanical control.
Implementation of simultaneous performance of two technological operations with different machine-and-tractor units
(Estonian University of Life Sciences, 2022) Bulgakov, V.; Olt, Jüri; Pascuzzi, S.; Nadykto, V.; Kyurchev, V.; Mitkov, V.; Santoro, F.; Estonian University of Life Sciences. Institute of Forestry and Engineering
The gap between two technological operations should be minimal in the production environment. For this, special combined (multi-operational) machine-and-tractor units (MTU) are used. Their agricultural machines have sequentially installed working devices for various technological purposes. In the absence of such MTUs, single-operation units are used. Such units more often have different working widths. For their simultaneous operation in the same field, the first unit (for example, a sowing unit) must have a wider width than the second one (for example, a rolling one). In practice, the opposite case occurs more often when the first unit's working width is less than the second unit's working width. As a result, the first machine-and-tractor unit delays the work of the second one. This article aims to develop the algorithm for the simultaneous operation of two machine-and-tractor units of different field performance. The first of them (a sowing unit) has a working width of 3.6 m, and the second (a rolling one) is 6.1 m. As a result, the following has been established using the example of processing a field of 80 hectares: the second unit should start its work (i.e., rolling the crops) when the first one (sowing) has sown a certain area. According to the formula proposed in the article, the size of this area is 44 hectares. Under natural working conditions, the second unit (rolling) started its work after the first (sowing) unit has sown 44 hectares of the field area. As a result, both units have completed the entire area with a half-hour gap, i.e., practically simultaneously and without delay from each other.
Breeding and genetic improvement of soft winter wheat with the use of spelt wheat
(Estonian University of Life Sciences, 2022) Diordiieva, I.P.; Riabovol, L.O.; Riabovol, Ya.S.; Serzhuk, O.P.; Nakloka, Iu.І.; Nakloka, О.P.; Karychkovska, S.P.
In the process of carrying out studies as a result of hybridization of soft wheat with spelt wheat, a number of new forms that differ in morphobiological and economically valuable features were obtained. The aim of the research was to expand the genetic diversity of soft wheat by hybridization with spelt wheat, analysis of the heterotic effect in hybrids in order to systematize the samples and obtain valuable original forms for the breeding process of creating high-yielding varieties. As a result of research the breeding technology of creating high-yielding forms of soft winter wheat by cross-species hybridization of Triticum aestivum L. × Triticum spelta L. has been improved. It has been determined that the plant height and ear length in hybrids are inherited by type of intermediate inheritance or negative dominance, the number of grains in the ear - by type of intermediate inheritance or positive dominance; ear grain weight - by type of superdominance or positive dominance. In F2 hybrids there is a dihybrid cleavage into forms with speltoid, squarehead and typical ear with a quantitative predominance of speltoid plants, which indicates the control of the ‘ear shape’ indication by two non-allelic genes. The ear shape of the soft wheat original varieties in relation to speltoid varieties turned out to be a recessive trait, but at the same time it was dominant to a squarehead form. Regardless of the genotypes of soft wheat included in the combination of crossbreeding with spelt wheat, red color ear indication was determined by a monogenic type of inheritance. Varieties of soft winter wheat Artaplot, Umanska Tsarivna and Freya have been created, which are included in the State Registry of Plant Varieties Suitable for Distribution in Ukraine and recommended for cultivation in Polissia.
The potential and limitations for applications of oat proteins in the food industry
(Estonian University of Life Sciences, 2022) Ibrahim, M.; Aav, Alice; Jõudu, Ivi; Estonian University of Life sciences. Institute of Veterinary Medicine and Animal Sciences. Chair of Food Science and Technology; Estonian University of Life sciences. Institute of Veterinary Medicine and Animal Sciences. ERA-Chair for Food (By-) Products Valorisation Technologies (VALORTECH)
Oat proteins have gained high attractive popularity in the market as future protein alternatives in various food products. The extracted oat protein fractions are characterised by a relatively high protein content and a unique amino acid profile compared to other cereal grains. From another aspect, the oat protein is separated unintentionally during the production of oat flours, oat drinks, and oat flakes which encourages the incorporation of oat proteins in the food industry to valorise the food wastes. Therefore, commercial oat proteins possess poor technofunctionality and water solubility in the usual environmental conditions for most food products; therefore, modification of oat proteins functionalities is highly recommended. Several modification methods, including chemical, physical and enzymatic, have been proposed to improve the techno-functionality of native oat proteins and their biological activities. This review highlights the nutritional value of the oat protein fractions, their techno-functional properties and their food industrial challenging limitations. Additionally, it summarises several prospective methods effective for boosting the functionality of oat protein fractions and broadening their application in a range of food industries (bakery, dairy, meat, and their alternative products) with an overview of their impact on humans, animals, and environmental health.
Evolution of productive and biodiversity features in lucerne fields of different ages
(Estonian University of Life Sciences, 2022) Argenti, G.; Parrini, S.; Staglianò, N.; Bozzi, R.
Medicago sativa is a legume forage crop characterized by high production of forage, with a notable nutritive value, but in mountain areas duration of the crop could be remarkably affected by severe environmental conditions. To assess the vegetation evolution of lucerne crops in relation to crop age, data from fields of lucerne of different ages were collected. The aim is the evaluation of lucerne productive performances, evolution of forage quality and assessment of recovery by autochthonous species that naturally recolonize the studied areas in relation to age of the cropped species. With increasing years, lucerne population was significantly decreased and replaced by different functional types of plants, such as perennial graminoids and short-lived forbs. Biodiversity increased significantly along time, and evolution of similarity indices demonstrated an evolution of vegetation toward that represented by reference grassland of the area. Productive characteristics of forage, in terms of aboveground biomass and quality, were negatively affected by age. Results permitted to assess the evolution of different features of lucerne for a mountain environment and to hypothesize the appropriate management for this resource, that could contemplate also the evolution towards the reconstitution of the reference habitat for the studied area.
An investigation of the amount of grain loss – using plant density and reel index of two popular brands of combine harvesters
(Estonian University of Life Sciences, 2022) Al-Slevani, S.S.A.; Hilal, Y.Y.; Rafiq, M.H.
Large wheat fields are cultivated in Iraq every year, especially in the Bazalan region. Although the grain production rate is high in Bazalan, the grain harvest loss is significant. Investigating wheat crop losses in different harvesting units is crucial to making decisions and improving working conditions. The current research was carried out to study the effect of the two popular brands of combine harvesters (New Holland TC56 and John Deere 1450 CWS) based on a relationship between the amount of loss from combine harvesters, reel indexes, and plant density. Three reel indexes (1, 1.5, and 2) and two plant densities (high-density and low-density sites) were considered. A randomised complete block split-plot design with three replications was carried out. The results showed positive superiority of the New Holland TC56 in the percentage of header losses, threshing losses, separation and cleaning losses, total harvest loss, and total loss with the highest performance efficiency of 97.725%; however, the harvester performance efficiency of the John Deere 1450 CWS remained within the acceptable loss limits. Finally, the best results were achieved with a 1.5-reel index level interacting with a high-density site; these results were statistically more significant than the differences between the New Holland TC56 and the John Deere 1450 CWS.
The impact of crop management regime on oil content and fatty acid composition in hulless and covered spring barley
(Estonian University of Life Sciences, 2022) Legzdiņa, L.; Ivdre, E.; Piliksere, D.; Vaivode, A.; Mieriņa, I.; Jure, M.
Lipids are a minor nutritional component of barley (Hordeum vulgare L.) grain and have not been as widely explored as the major components. The aim of this study was to investigate the effect of genotype and environment, including conventional farming system with three crop management regimes, differing in agrochemical input, and organic farming system, on oil content and fatty acid composition in grain of two covered and four hulless spring barley genotypes during two growing seasons. Genotype significantly affected oil content and it was on average 4.26% and ranged in individual barley samples from 2.87 to 5.53%. We found linoleic, oleic, palmitic, α-linolenic, stearic and capric fatty acids in average proportions of 55.6; 21.3; 18.6; 3.7; 0.6 and 0.4%, respectively. Higher average oil content and proportion of α-linolenic acid was found in covered barley. Crop management regime did not significantly affect oil content but had some effect on the proportion of linoleic, α-linolenic, oleic and stearic acid. Decrease of chemical inputs was in favour of oil content and proportion of α-linolenic, oleic and stearic acids but did not promote linoleic acid. Waxy hulless barley line with high oil content and a very high proportion of linoleic acid was identified.
Morphophysiological peculiarities of productivity formation in columnar apple varieties
(Estonian University of Life Sciences, 2022) Havryliuk, O.; Kondratenko, T.; Mazur, B.; Kutovenko, V.; Mazurenko, B.; Voitsekhivska, O.; Dmytrenko, Y.
Differentiation of generative buds is one of the most important biological processes of plant transition from vegetative to generative state. This process is key to the problem of creating regular fruit-bearing and early-fruiting plantations. The article provides information on the organogenesis of buds in plants of columnar apple varieties in the Forest-Steppe of Ukraine, which allows establishing the features of this process in complex fruit formations of different ages, and the levels of their productivity and longevity. Research to study the organogenesis of different-age fruit formations of columnar apple varieties was conducted in the northern part of the Forest-Steppe of Ukraine during 2016–2020. The efficiency of realization the plants biological potential of all studied columnar apple varieties at III–IV and V–IX stages of organogenesis was high: the largest number of buds from their total number differentiated into generative on trees varieties ‘Sparta’, ‘President’, ‘Bilosnizhka’, ‘Valuta’ and ‘Tantsivnytsia’ (37–51%), the smallest in ‘Favoryt’ and ‘Bolero’. The biggest number of flowers per one potentially generative bud was formed by plants of ‘Tantsivnytsia’ and ‘Bilosnizhka’ varieties. The lowest level of ovarian loss during the X stage of organogenesis was observed on plants of ‘Valuta’, ‘President’, and ‘Tantsivnytsia’ varieties (41–49%), and the highest - in ‘Favoryt’ variety (up to 83%). More effective realization of potential productivity at the XI stage of organogenesis occurred in plants of ‘President’, ‘Valuta’ and ‘Tantsivnytsia’ varieties; their trees on one potentially generative bud formed - 0.27–0.38 fruits. The coefficient of determination indicates that the influence of meteorological conditions of the year on the passage of III–IV stages of organogenesis is 46%; V–IX stages - 42%; Stage X - 17%; Stage XI - 24%.
Effects of some agronomic practices on the quality of starch content of maize grains
(Estonian University of Life Sciences, 2022) Fejér, P.; Széles, A.; Horváth, É.; Rátonyi, T.; Ragán, P.
The use of maize, both as main and by-product, is extremely versatile and diverse. The highest amount of carbohydrate within maize is found in the form of starch (C6H10O5)x. In terms of industrial starch, maize is the most important raw material. Fodder maize is primarily an energy source due to its high starch content, and its protein and oil content are less important. It was found that starch and protein content, which are negatively correlated with each other, are significantly affected by fertilizer doses. The experiment is located in the Hajdúság Loess Plateau, its soil is loess-based deep humus layered calcareous chernozem. The following treatments were applied in the scope of the polyfactorial experiment: Tillage: T1 = winter ploughing, T2 = strip tillage, T3 = ripping. Crop years: 2017, 2018 and 2019. Fertilization treatments: N 0 kg ha-1 P2O5 0 kg ha-1 K2O 0 kg ha-1 (control); N 80kg ha-1 P2O5 60 kg ha-1 K2O 90 kg ha-1 and N 160 kg ha-1 P2O5 60 kg ha-1 K2O 90 kg ha-1. Analysis of the nutritional component was carried out by means of a Foss Infratec TM 1241 Grain Analyser. In terms of fertilization treatments, the highest (64.42%) maize starch content was measured for the control treatment, while the lowest starch content was recorded in the case of the 160 kg N ha-1 treatment (62.62%). The analysis of the crop year effect showed that 2018 was the most favourable year for the maize starch content of the examined samples (65.76%). Of the studied years, the lowest starch content was measured in 2017 (61.78%).
Research into properties of blue melilot and fenugreek cultivated using different sowing times
(Estonian University of Life Sciences, 2022) Fedosiy, I.; Bobos, І.; Zavadska, O.; Komar, O.; Tonkha, O.; Furdyha, M.; Polishchuk, S.; Arak, Margus; Olt, Jüri; Estonian University of Life Sciences. Institute of Forestry and Engineering
The paper presents the results of the research into the properties of blue melilot (Melilotus caeruleus (L.) Desr.) and fenugreek (Trigonella foenum graecum L.) with regard to the set of their economy-and-biology and biochemical indices in relation to the dates of their sowing. It has been established that the two species under consideration feature wide ranges of index variability depending on the sowing term and the weather conditions. The earliest ripening terms have been recorded for species in case of summer sowing dates (decade I of June), when short growing season lengths of 36–37 days were observed. At the same time, in terms of heavy plant herbage yield obtained from species in the green conveyor system, the early spring (decades II–III of April) and late spring (decade I of May) sowing terms are more suitable providing a herbage yield of 5.7–6.9 t ha–1 in case of blue melilot and 7.3–9.3 t ha–1 for fenugreek, with a solids content of 12.4–28.4%, total sugars of 2.5–5.0% and vitamin C - 38.0–51.8 mg (100 g)-1 . For the purpose of obtaining the spice named ‘Greek hay’ (foenum Graecum), a better choice is to cultivate fenugreek with early spring (decades II–III of April) and late spring (decade I of May) sowing times, as in this case a greater vegetation mass develops, resulting in a plant dry weight yield of 1.3–1.4 t ha–1. An increase in the total precipitation by 1 mm has contributed to the variation of the herbage yield within the range of 15.0 to 77.3 kg ha–1, dry matter yield - 0.693 to 25.9 kg ha–1. High seed yield has been noted in case of sowing the species in early spring (decades II–III of April), where the seed yield of blue melilot was equal to 0.4 t ha-1, fenugreek - 2.0 t ha-1 , their 1,000 seeds having a weight of 0.71 and 9.7 g, respectively.
Possibilities of cucumber powdery mildew detection by visible and near-infrared spectroscopy
(Estonian University of Life Sciences, 2022) Alsiņa, I.; Bimšteine, G.; Dubova, L.; Kaņeps, J.; Kviesis, K.; Bankina, B.; Dūma, M.; Avotiņš, A.
Cucumbers are one of the most demanded and widely grown greenhouse vegetables. Important factors that influence quality and quantity of yield are diseases. Powdery mildew (caused by Podosphaera xanthii and/or Golovinomyces cichoracearum), is one of the most harmful cucumber diseases. Early detection of mildew via non-destructive methods can optimize schemes of fungicide application. The study aimed to find regularities in the reflected light spectra, indices described in the literature, and severity of mildew. Plants were grown in the polycarbonate greenhouse under artificial lighting in a 16 h photoperiod with PAR at the tips of plants 200 ± 30 µmol m-2 s-1. Leaf reflection spectra were obtained using spectroradiometer RS-3500 (Ltd. Spectral Evolution). Spectral range 350–2,500 nm, bandwidth 1 nm. The severity of cucumber mildew was evaluated using 10 point scale (0- no symptoms, … 9 - the plant is dead). The vegetation indices found in the literature have been calculated. The obtained results show that the calculated indices have different sensitivities. The strongest correlation between the degree of cucumbers infection with powdery mildew and the light reflectance spectrum was found in the green range of visible light around 550 nm. Disease-Water Stress Index-2 (DSWI-2), Structure Intensive Pigment Index (SIPI), and Normalized Difference Vegetation Index (NDVI) are the most suitable indices for determining powdery mildew in cucumbers. New indices for detection of powdery mildew have been created. None of the studied indices allows determining the powdery mildew at the early stages of disease development when powdery mildew severity is below 10%.
Bonding performance of wood of fast-growing tree species eucalyptus (Eucalyptus grandis) and radiata pine (Pinus radiata D.Don) with polyvinyl acetate and emulsion polymer isocyanate adhesives
(Estonian University of Life Sciences, 2022) Iejavs, J.; Šķēle, K.; Grants, E.; Uzuls, A.
Fast-growing imported plantation tree species have become an available wood resource for Europe’s wood industry in the last decades. This sustainable alternative may reduce the gap between the increasing demand for and decreasing supply of the local tree species. The aim of the study was to evaluate the performance of eucalyptus (Eucalyptus grandis) and radiata pine (Pinus radiata D.Don) wood in face-bonding with polyvinyl acetate (PVAc) and emulsion polymer isocyanate (EPI) adhesive for the production of non-structural semi-finished glued laminated timber members for window manufacturing. Test specimen preparation and testing were performed according to European standards. Tensile shear strength and wood failure percentages were determined as bonding performance indicators for 3 adhesives and 3 selected bonding parameters (pressure, pressing time and adhesive spread) in 27 variations after boiling the specimens in water. According to the results, the bonding variables influence the glue-line tensile shear strength and wood failure percentages. Bonding pressure and pressing time were evaluated as the most significant factors influencing shear strength of bonded joints. For all bonding variations the average level of shear strength from 3.45 to 5.23 MPa were reached for PVAc adhesive and from 3.78 to 9.65 MPa for EPI adhesives. Both EPI adhesives provide higher performance compared to PVAc adhesive. In the case of bonding fast-growing tree species, the highest shear strength values were achieved using the lowest pressure of 0.8 MPa, adhesive spread from 150 to 180 g m-2 and longest pressing time of 40 min. Based on the general evaluation of the results, it can be stated that the wood of eucalyptus and radiata pine bonded with both EPI adhesives presents great potential for non-structural semi-finished glued laminated timber member production, especially for the use in humid conditions.
Phosphate solubilization potential of indigenous rhizosphere fungi and their biofertilizer formulations
(Estonian University of Life Sciences, 2022) Balogun, D.A.; Oke, M.A.; Rocha-Meneses, L.; Fawole, O.B.; Omojasola, P.F.; Estonian University of Life Sciences. Institute of Technology
The harmful effects of chemical fertilizers on soil, plants, and eco-systems have stimulated the growth of the global biofertilizer market. However, biofertilizer use remains limited in developing countries due to inadequate research and poor technology. The use of readily available materials for biofertilizer production can be a good starting point. This study aimed to investigate phosphate-solubilizing potentials of soil fungi and the shelf-life of their biofertilizer formulations using sawdust and charcoal as carriers. Soil samples from the rhizosphere were cultured on Pikovskaya (PVK) agar, and the best phosphate solubilizers (Aspergillus niger, Aspergillus fumigatus and A. flavus) were screened for their phosphatesolubilization potentials on solid medium. Results obtained showed that A. niger had the highest solubilization index of 1.72, followed by A. fumigatus, and A. flavus with a solubilization index of 1.01 and 0.95, respectively. Optimization studies showed that after 5 days of incubation, A. niger, A. flavus and A. fumigatus solubilized 149, 112 and 126 mg L-1 of phosphate, respectively. These values increased to 549 mg L-1 on day 11 for A. niger, 379 mg L-1 on day 9 for A. flavus and 430 mg L-1 on day 9 for A. fumigatus. Furthermore, A. fumigatus and A. flavus proved to be better inoculants than A. niger as they maintained higher CFU g-1 counts throughout the experiment. Also, sawdust supported higher counts of the three inoculants than charcoal and was thus the best carrier. The findings demonstrated that these aspergilli can be harnessed for improving soil fertility and plant development.
Potential of multivariate analyses of X-ray fluorescence spectra for characterisation of the microchemical composition of plant materials
(Estonian University of Life Sciences, 2022) Brangule, A.; Bērtiņš, M.; Vīksna, A.; Bandere, D.
This work describes a method for the rapid element analysis of plant material using ED-XRF in conjunction with chemometrics. An effective analysis method is developed by measuring certified reference materials (CRM) of plant materials (algae, cabbage, lichen) covering major chemical elements with ED-XRF, to overcome the matrix effect. All samples have been measured additionally by ICP-MS. The ICP-MS analysis was used for missing information on the concentration of some elements in certificated standards. In addition, ICP-MS with CRM has been used to determine sample related element sensitivity for microelements for ED-XRF analyses. The ED-XRF spectral patterns were used for multivariate principal component analyses by SIMCA strategy instead of each element concentration calculation. The model allows quickly analyse samples for similarity and differentiate them based on a little difference in spectral pattern, which corresponds to a minor difference in element concentration pattern. Samples with specific chemical composition could be easily spotted for in-depth analysis. The proposed strategy for plant material sample chemical composition screening allows the quick method to improve laboratory work efficiency, reduce unnecessary analysis and rapid method for control reliability of results of more complex chemical methods, such as ICP-MS.
The impact of ventilation type on the heat load of dairy cows
(Estonian University of Life Sciences, 2022) Hauliková, A.; Lendelová, J.; Mihina, Š.; Kuchar, P.
Heat load in cattle causes deterioration of health and reduced production of milk. Therefore, it is necessary to protect cows by appropriate passive and active means and monitor the air quality in barns. Based on several indicators of environmental quality, is possible to make a more comprehensive assessment of the microclimate and more precise conclusions. This study, was monitoring the values of air temperature, relative humidity, and air velocity in two barns with the same volume and layout with floor dimensions of 26.6 m × 62.1 m. In barn 1, roof ridge of which had underwent only partial reconstruction, there were installed fourteen basket fans with a total fan performance Q(1)fans = 218,400 m3 h -1 . In barn 2, there were twelve panel fans with a total fan performance Q(2)fans = 289,320 m3 h -1 . The resulting THI, HLI and ETIC values were compared in relation to each other and in relation to the recommended values. Despite the operating ventilation technology and enlargement of wall openings, the above-limit values of climatic characteristics were observed in both barns during tropical days. There were no differences between the barns (p ˃ 0.05), in barn 1: THI(1) = 83.10 ± 0.51; HLI(1) = 85.62 ± 1.42; ETIC(1) = 27.24 ± 0.31, and in barn 2: THI(2) = 83.12 ± 0.34; HLI(2) = 85.77 ± 1.50; ETIC(2) = 27.29 ± 0.28, however, there were found significant differences in values of temperature indices obtained in the detailed measurements at points arranged perpendicularly, as well as parallelly, to the direction of air velocity in the animal zone (p < 0.05).

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