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2020, Vol. 31, No. 2

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  • Kirje
    Modular-vitality and ideotypical approach in evaluating the efficiency of construction of oilseed radish agrophytocenosises (Raphanus sativus var. oleifera Pers.)
    (Estonian Academic Agricultural Society, 2020) Tsytsiura, Yaroslav H.
    The paper provides the results of a multi-year study of the peculiarities of phytocoenology of oilseed radish agrophytocenosises using various methods of its condition assessment and studying the tactics of plant vitality strategy. A comprehensive assessment was made of the impact of changes in inter-row spacing width, sowing rates and fertilizer on the formation of different plant ideotypes, the variability of their morphological features and general indicators of viability. Three ideotypes of oilseed radish plants in the vertical study of agro-phytocenosises were identified, based on which a detailed analysis of the variability of each group and a statistical assessment of the reliability of its existence was made. The peculiarities of morphological integration of each tier were analyzed and its influence on the formation of the overall field capacity was assessed. Based on the modular and vitality grouping, the efficiency and feasibility of combining different stand density and fertilizer options in the range of 30–90 kg of primary material per 1 hectare were evaluated. Due to the application of regression analysis, the impact of climatic conditions on the formation of different morphological types of plants and the nature of relationships between oilseed radish plants in cenosises of different stand densities with different fertilizer options was assessed. The main perspective directions of further research on the peculiarities of the creation of highly productive and highly adaptive agrophytocenosises of oilseed radish are outlined.
  • Kirje
    Experimental research into impact of kinematic and design parameters of a spiral potato separator on quality of plant residues and soil separation
    (Estonian Academic Agricultural Society, 2020) Ruzhylo, Zinoviy; Bulgakov, Volodymyr; Adamchuk, Valerii; Bondarchuk, Anatoliy; Ihnatiev, Yevhen; Krutyakova, Valentyna; Olt, Jüri; Institute of Technology. Estonian University of Life Sciences
    The experimental investigations carried out in field production conditions have proved that the process of cleaning potato tubers from extraneous material with the use of a spiral separator takes place due to the active conveyance of the heap by the turns of the cantilever mounted cleaning spiral springs. The cleaning spiral springs not only rotate at the set angular velocity, but simultaneously their cantilevered ends perform oscillatory motion, which arises due to the deflection of their longitudinal axes under the action of the weight of the potato heap fed into the work zone of the separator. The results obtained in the process of the field experiment investigations carried out by the authors have provided for obtaining the relations that enable selecting the optimum design and kinematic parameters of the spiral-type potato cleaning devices for the targeted separation rate and, accordingly, estimating their impact on the quality of the performed work process.
  • Kirje
    Influence of fertilizing with modern complex organic-mineral fertilizers to grain yield and quality of winter wheat in the southern steppe of Ukraine
    (Estonian Academic Agricultural Society, 2020) Panfilova, Antonina; Gamayunova, Valentina; Smirnova, Irina
    This article presents the results of using different varieties, variants of nutrition and their impact on the yield and grain quality of winter wheat. Experimental studies were conducted during 2011–2016 on the experimental field of the Mykolayiv National Agrarian University, Ukraine. The technology of growing winter wheat in the experiment, except the studied factors, was generally accepted to the existing zonal recommendations for the southern steppe of Ukraine. The predecessor was peas (Pisum sativum L.) It was determined that the higher grain yield and slightly better quality indicators differed grain of the studied winter wheat varieties with the joint use of pre-sowing application of N30P30 and foliar fertilizing of winter wheat crops twice during the vegetation season by Escort-bio. Thus, for this variant of nutrition, the crude gluten content of winter wheat grain was 24.2 up to 25.1%, the protein content was 12.9 up to 13.2%, and the conditional protein yield of from 1 ha of sowing area was 0.58–0.66 t depending on the studied variety. At the same time, on average, according to the nutrition factor, plants of the 'Zamozhnist' variety in comparison with the 'Kolchuga' variety formed more by 9.3% of the grain, which had the best quality indicators.
  • Kirje
    Bio-fertilizer activity of Trichoderma viride and Pseudomonas fluorescens as growth and yield promoter for maize
    (Estonian Academic Agricultural Society, 2020) Nepali, Bikram; Subedi, Subash; Bhattarai, Sabin; Marahatta, Santhosh; Bhandari, Devashish; Shrestha, Jiban
    The bio-fertilizer potential of Trichoderma viride and Pseudomonas fluorescens on growth and yield performance of open-pollinated maize variety Rampur Composite was studied at the research farm of Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal during the winter season of 2018/19. The experiment was laid out in randomized complete block design with seven treatments (T1: recommended dose of NPK (120:60:40 kg NPK ha–1), T2: T. viride only, T3: P. fluorescens only, T4: T. viride + 50% NPK; T5: P. fluorescens + 50% NPK; T6: T. viride + P. fluorescens + 100 % NPK, T7: control) and replicated thrice. The package of agronomic practices was followed as per national recommendation. The result revealed that T. viride + 50% NPK enhanced most of the growth components like plant height (103%), leaf number (9.77%), stem diameter (73.98%), root length (40.57%), leaf area index (173.28%), leaf biomass (83.36%) and stem biomass (127.72%) of maize compared to the control. Similarly, the higher cob biomass (641 g), yield (5708 kg ha–1) and thousand kernel weight (295 g) were recorded in the plot applied to P. fluorescens + 50% NPK. The use of Trichoderma viride and Pseudomonas fluorescens with a half-dose of recommended fertilizers may increase the vegetative growth and yield of maize and may also help to reduce the rate of chemical fertilizers in maize.
  • Kirje
    Ülevaade nitritite ja nitraatide sisaldustest lihatoodetes Eestis
    (Estonian Academic Agricultural Society, 2020) Jalakas, Sirje; Roasto, Mati; Reinik, Mari; Elias, Terje; Eesti Maaülikool. Veterinaarmeditsiini ja loomakasvatuse instituut. Toiduhügieeni ja rahvatervise õppetool
    This study examined the nitrite and nitrate content in processed meat products in Estonia. The study shows the levels of nitrites and nitrates in meat products and compares the results with data from the previous study periods. All meat products, which needed heat treatment according to the manufacturer's instructions, were heat-treated prior analyses. Among analysed meat products (n=164), the highest nitrite concentration was 93.1 mg kg–1 and it was determined in uncooked meat preparation product. The overall mean nitrite concentration among nitrite contained meat products varied from 9.7–30.3 mg kg–1 depending on the meat product category. The highest mean nitrite concentrations were found in sausages and pates. There were large differences in the nitrite content of the products of different producers, ranging from the detection limit to 93.1 mg kg–1. The largest differences in nitrite contents were observed in the cooked sausages of one manufacturer, in which the nitrite content was from the detection limit up to 61.5 mg kg–1 in the product. The nitrite and nitrate contents of different meat products also varied widely between producers and were different for each product group. By the Regulation (EC 1333/2008) taking into account the maximum levels for nitrites and nitrates allowed to be added to the meat products, there were no exceedances detected. In the comparison of previous and present study periods, it can be summarised that sodium nitrite (NaNO2) levels are lower in cooked sausages, smoked sausages and wieners, and the content of sodium nitrate (NaNO3) in various meat products is considerably decreased.
  • Kirje
    Precision agriculture in the North of Kazakhstan
    (Estonian Academic Agricultural Society, 2020) Abdullaev, Kendje; Irmulatov, Bakkit; Komarov, Аndrei; Nugis, Edvin
    The precision farming system has been used in the North of Kazakhstan where specialized landfill on an area of 3000 ha was formed. In the fields of the landfill, detailed agrochemical survey (accuracy) of soil samples of the southern carbonate chernozem for grid cells 1 ha and 5 ha of fieldnet treatments with were conducted. Further differentiated fertilization was carried out both with the help of Amazone ZA-M and with the use of the Bourgault sowing complex. Monitoring of the state of the soil, plant development and work performed was carried out both by traditional methods and using modern remote sensing data. After the introduction of precision farming technologies in the North Kazakhstan from 2019 precision farming technologies has been used. As a result of the work carried out only from the introduction of one element of precision farming – differentiated rationing of fertilizer application, an increase in the yield of spring wheat 'Astana' by 9.6–19.2% to the standard economic technology was established. Research results have shown that the share contribution with a high yield of 2000 kg ha–1 was significant for a sampling grid cells 1 ha of fieldnet (40–47%) and less significant for a sampling grid cells 5 ha of fieldnet (15–20%). Hence it follows that the choice of a fieldnet with grid cells 1 ha is more preferable. Due to the use of a differentiated application system the savings from reducing the consumption of mineral fertilizers for the unit of the relay have had 69.26 EUR. Our novel research has shown that for characterizing the state of plants an assessment is given which was performed using test sites 1 and 5 ha grid cells of fieldnet treatments. In this case, we have used the vegetation indices NDVI – Normalized Difference Vegetation Index. At the same time, this index has changed relatively synchronously with the results of the yield of the spring wheat.
  • Kirje
    Nutrient intake, digestibility and nitrogen balance of West African Dwarf goats fed cassava root sievate and cassava leaf meal mixture in their diets
    (Estonian Academic Agricultural Society, 2020) Jiwuba, Peter-Damian Chukwunomso
    Four West African Dwarf (WAD) bucks averaging 7.62 kg and aged 8–10 months were used to determine the intake, body weight changes, digestibility and nitrogen balance of cassava root sievate-cassava leaf meal mixture based diets. The four experimental diets (T1, T2, T3 and T4) were formulated to contain palm kernel cake, brewers' dried grain, molasses, bone meal, limestone, meal, common salt and 0, 20, 40 and 60% cassava root sievate-cassava leaf meal mixture at the rate of 3:1 res-pectively. The diets were assigned individually to the four animals in metabolism cages in a 4×4 Latin square design experiment. Feed intake, body weight gain, dry matter intake (DMI), nutrient digestibility and the nitrogen balance status of each animal were measured. Results on proxi-mate composition revealed that the nutrient requirements of the goats were adequate. The DMI for the supplement, total DMI, total DMI (g kg–1 W0.75), CF intake were highest (P < 0.05) for T4. Average body weight gain (g day–1) and average body weight gain (g kg–1 W0.75) were best (P < 0.05) for T3 and T4. Crude protein digestibility was best (P < 0.05) for T4. Neutral detergent fibre and acid detergent fibre digestibilities were best for T3 and T4. Nitrogen intake (g day–1), nitrogen balance (g day–1) (g W–1 kg0.75), nitrogen retention (%), nitrogen absorbed (g day–1) (g W–1 kg0.75), apparent N digestibility (%) and efficiency of nitrogen utilization were all best (P < 0.05) for and T4. The diet (T4) containing 60% CRSCLM mixture was recommended among the other diets for feeding goats, as it had better performance concerning nutrient intake, body weight gain, nutrient digestibility and utilization.
  • Kirje
    Short communication : Immunohistochemical study of sodium-dependent glucose co-transporters in ostriches kidneys
    (Estonian Academic Agricultural Society, 2020) Hussar, Piret; Dūrītis, Ilmārs; Popovska-Percinic, Florina; Järveots, Tõnu; Institute of Veterinary Medicine and Animal Sciences. Estonian University of Life Sciences
    Out of the two families of glucose transporters identified, the sodium-dependent glucose co-transporters contribute to renal glucose reabsorption. Due to the lack of knowledges of the localization of SGLTs in bird's kidneys, the present study aimed to immunolocalize Na+-glucose co-transporters SGLT1 and SGLT2 in ostrich's kidneys. In the study kidney material derived from five 14 days old female ostriches. Material 0.5–1.0 cm in diameter was fixed in 10% formalin, dehydrated, embedded into paraffin; thereafter slices 7 μm in thickness were cut and deparaffi-nized, followed by immunohistochemical staining with polyclonal primary antibodies Rabbit anti-SGLT1 and Rabbit anti-SGLT2 (Abcam, UK) according to the manufacturers' guidelines (IHC kit, Abcam, UK). Our study revealed the immunohistochemical localization of SGLT1 and SGLT2 in the proximal tubules of the renal cortex. The immunohisto-chemical locations of sodium-dependent glucose transporters resembled those in mammals.
  • Kirje
    Analytical study of soil strain rate with a ploughshare for uncovering slit
    (Estonian Academic Agricultural Society, 2020) Solona, Olena; Kovbasa, Volodymyr; Kupchuk, Ihor
    The article is devoted to solving one of the most important tasks of substantiating rational design and technological parameters of the working body for the installation of elements of subsurface irrigation. To reduce the frictional resistance during pulling of intra-soil irrigation communications, it becomes necessary to form a cavity inside the soil. The energy efficiency of such a process is determined by the traction resistance and directly depends on the normal and shear stresses of the soil as a result of its relative deformation during interaction with a special working body – the share of a mole plough. The geometric shape and kinematic parameters of the share, together with the mechanical characteristics of the soil, have the greatest influence on the nature of the relative deformation. Therefore, the purpose of the article is to determine the functional dependences of the components of the soil deformation rates on the geometric and kinematic parameters of the working body surface. These equations are necessary to determine the stress components in the soil, which make it possible to determine the compaction of the soil on the walls of the formed cavity (molehill), as well as the components of the forces of resistance to the movement of the working body.
  • Kirje
    Eesti erosioonist häiritud muldade orgaanilise süsiniku- ja lämmastikusisaldus
    (Estonian Academic Agricultural Society, 2020) Kõlli, Raimo; Kauer, Karin; Tõnutare, Tõnu; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. Mullateaduse õppetool
    The work is dedicated to the characterization of erosion-affected soils' (EAS) humus status (HS) in pedo-ecological conditions of South-Eastern Estonia. For understanding HS of EAS their organic carbon (OC) and total nitrogen (NT) sequestration capacities and the ratio C:N was studied by separate soil layers. The average data about soil OC and NT contents (g kg–1) and superficial densities (Mg ha–1) are given by arable soil species. The analysis of reflecting EAS HS on four research areas (Valgjärve, Otepää, Haanja and Mooste) was carried out on the basis of four different origin databases. The analysis of OC content is done by Tjurin and NT by Kjeldahl. In soil associations of erosion-affected areas' the following groups of soils were distinguished: eroded (E), deluvial (D), neutral (N) and non-eroded (En) soils. The HC thicknesses of research area Valgjärve E soils are in limits 18–23 cm, D soils 30–65 cm and of En soils 22–27 cm. The medians of same soils OC concentrations are accordingly 9.4, 11.2 and 10.9 g kg–1 and ratios C:N accordingly 9.8, 9.4 and 10.2. The OC stocks given in the limits of quartiles are in E soils 24–36, D soils 51–143 and En soils 32–49 Mg ha–1. Therefore on eroded areas the perpetual continuums of soil properties' (among these HS) changes may be followed and it is very complicated to separate soil contours on 1:10 000 soil maps. In this work the transitional areas between E and D soils are characterized via N soils. On erosion-affected areas the E and D soils form different soil associations with auto- and hydromorphic normally developed non-eroded soils, where very commonly as well the fluvial (abnormal) soils are presented. The relatively high pedodiversity caused by the areas high geodiversity, is the requisite to the high biodiversity. In erosion-affected regions is extremely important to maintain agricultural activity, as with this is ensured the persistence of naturally beautiful landscapes. The soil cover with EAS acts as accumulator of formed on the same area soil OC.
  • Kirje
    Effect of water deficit and foliar application of amino acids on growth and yield of eggplant irrigated by two drip systems under greenhouse conditions
    (Estonian Academic Agricultural Society, 2020) Bader, Basim Raheem; Abood, Mohammed Ali; Aldulaimy, Saad Enad Harfoush; Al-Mehmdya, Shuker Mahmood Hassan; Hamdi, Ghassan Jaafar
    Water deficit in semiarid areas limits eggplant (Solanum melongena L.) production and growth indicators. Suitable drip irrigation system and foliar application of amino acids may help overcome water deficit. In this work, the effects of drip irrigation system [Grand flow regulators (GR) and T-Tape], water deficit (50, 75, 100% based on field capacity) and foliar application of amino acids at 0, 100 and 200 mg L–1 on water relation of leaf's, yield and field water use efficiency (WUEf) of eggplant were studied. The experiments were arranged in a split-split plot design within a completely randomized distribution each repeated three times. GR irrigation system treatment produced the highest relative water content (RWC), most yield (TY), WUEf and the lowest of water saturation deficit (WSD) which were 74.71%, 6.50%, 5.97 t ha–1, 2.11 kg m–3 and 23.09%, respectively. The lowest water uptake capacity (WUC) and relative membrane permeability (RMP) was obtained in T-Tape irrigation system treatment (0.43% and 59.45%, respectively). The 100% irrigation level revealed higher RWC (79.32%), WSD (7.38%), most TY (6.93 t ha–1), the least of WSD (18.00%), WUC (0.28%) and RMP (39.40%). The maximum of WUEf (2.37 kg m–3) was obtained from 50% irrigation level. The foliar application of 200 mg L–1 Amino acids rate resulted in significantly maximum RWC (81.50%), WRC (7.19%), TY (6.75 t ha–1) and WUEf (2.51 kg m–3) and least WSD (15.88%), WUC (0.33%), RMP (52.02%). GR drip irrigation system is best for water use efficiency; 200 mg L–1 Amino acids produced the best response for most studied traits.
  • Kirje
    Short communication: Changes of compatible solutes content in Triticum aestivum and Triticum dicoccum seedlings in response to drought stress
    (Estonian Academic Agricultural Society, 2020) Smirnov, Oleksandr; Zinchenko, Andrii; Karpets, Leila-Аnastasiia; Kovalenko, Mariia; Taran, Nataliya
    The influence of drought stress modelling by polyethene glycol (PEG) on water status, total soluble protein, proline and carbo-hydrates content in the roots and leaves tissues of three drought resistance wheat genotypes – Triticum aestivum L. (Podolianka, Favorytka) and Triticum dicoccum Schrank. (Holikovska) have been studied. Tested varieties of bread wheat and emmer wheat presented the resilience-aniso-hydric strategy for water balance regulation retaining a high level of relative water content, great variability in organic solutes with osmo-protective properties (total soluble protein, total carbohydrates and free proline) accumulation and retaining the level of low molecular weight proteins in response to drought with noticeable distinctions amid the varieties. However, drought stress increased the efficiency of accumu-lation of osmoprotectants either protein or carbohydrate nature in all three tested varieties of wheat seedlings.
  • Kirje
    Growth and yield responses of potato (Solanum tuberosum L.) to biochar
    (Estonian Academic Agricultural Society, 2020) Upadhyay, Kalika Prasad; Dhami, Narayan Bahadur; Sharma, Prem Nidhi; Neupane, Janaki Datta; Shrestha, Jiban
    The response of five types of biochar (Lantana camara, Ipomoea carnea, rice husk, sawdust, no biochar) on growth and yield attributes of potato was evaluated. The experiment was laid out in randomized complete block design with six replications in rainfed areas of two different environments (Jiri in 2018 and Pawati in 2019) of Nepal. The popular early maturing potato variety 'Desiree' was used in the experiment. The spacing was maintained 60 cm between rows and 25 cm between plants in the plot size of 7.2 m2. Seed tubers were planted in the 1st week of February and harvested in the 4th week of May. Recommended fertilizers (100:60:60 kg ha–1 NPK + 20 t ha–1 farmyard manure) and biochars at 2 t ha–1 were applied to the soil. Seed tubers were completely covered with an equal amount of biochar before covering with the soil. The results revealed that the total yield and marketable yield of potato varied with biochars types. The potato tuber yield was found higher and red ants infestation was lower in plots applied with biochars as compared to control plots (without biochars). The use of biochars derived from Lantana camera produced the highest number of tubers (6.1 tubers plant–1), the greatest weight of tubers (286.1 g plant–1) and the least damage of red ants on tubers (4.7%) followed by sawdust (6.0 tubers plant–1, 263.6 g tuber weight plant–1 and 7.8% damaged tubers by red ants). The findings provide new information on the understanding of biochar effect on increased marketable yield of potato in rainfed lands by reducing damage from red ants.
  • Kirje
    Sublethal effect of glyphosate [N-(phosphonomethyl)glycine] on growth performance and biochemical activities in some organs of Clarias gariepinus (Burchell, 1822) fingerlings
    (Estonian Academic Agricultural Society, 2020) Akinbadewa, Adedamola Oladapo; Adewole, Henry Adefisayo; Olaleye, Victor Folorunso; Ogundepo, Gbenga Emmanuel
    The effect of the sublethal concentration of glyphosate [N-(phosphonomethyl)glycine] on growth and some biochemical indices in the organs of African catfish (Clarias gariepinus, Burchell 1822) fingerlings in a static bioassay setup was studied to provide information on the sublethal toxicity effect of glyphosate on C. gariepinus fingerlings. Two hundred and seventy (270) fingerlings of C. gariepinus (10.02 ± 0.20g) randomly stocked at 30 fish per tank in triplicate were exposed to varying concentration (0, 2.75 ppm and 5.00 ppm) of glyphosate for 70 days. The results of the study showed that the determined growth parameters decrease with increase glyphosate concentration (except specific growth rate). The highest mortality rate was recorded in the treatment with the highest phosphate concentration (5.50 ppm). The enzymatic analyses of the fish tissue revealed that Na+/K+-ATPase activity which ranged from 0.20 to 19.29 μM Pi min–1 mg–1 protein in all the fish tissues increase with increase glyphosate concentration in the fish muscle and liver, and decreases with increase in glyphosate concentration in the gills. However, the muscle and liver malate DH activities decreased with increase in glyphosate concentration while the lactate DH activity increases with increase intoxicant concentration in the muscle (with the highest treatment having a threefold increase). Generally, the enzymatic activities of fish tissues followed the order: Malate DH >Na+/K+-ATPase>Lactate DH. The study concluded that the glyphosate concentration negatively impacted the growth and survival of C. gariepinus and also had a pronounced effect on the enzymatic activities of the studied organs.
  • Kirje
    A theoretical and experimental study of combined agricultural gantry unit with a mineral fertiliser spreader
    (Estonian Academic Agricultural Society, 2020) Bulgakov, Volodymyr; Adamchuk, Valerii; Kuvachov, Volodymyr; Shymko, Lyubov; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
    Operations to apply mineral fertilisers to the soil are an important part of practically every form of agricultural technology. The current global trend of transitioning to bridge and gantry-type agricultural systems leaves the unanswered relevant question of the effectiveness of the technological process of applying mineral fertilisers to the soil. This is relevant because, in gantry agriculture, a section of the arable soil is separated as an engineering area. This is why the main difference in gantry agriculture from traditional methods of the bulk spreading of fertiliser onto a field is that, with gantry systems, the amount of fertiliser that lands within the engineering zone are limited. This significantly affects the manufacturing costs involved in the entire area of agricultural technology and, as a result, the production costs of the end product. This study aimed to research the patterns that are apparent in affecting the parameters involved in the use of gantry-type equipment when applying fertiliser with the parameters and operational modes of a specially-developed electric spreader of mineral fertilisers. The physical object of the study was the agricultural gantry equipment that had been developed by the authors. This equipment, which is used for spreading fertiliser, was in the form of a tractor-mounted, suspended, single-disc spreader which was known as JarMet, and which had especially been modified to run from an electrical supply. The study indicated that the biggest influence on the speed of rotation of the centrifugal disc in the mineral fertiliser spreader stems from its height above the ground, the distance of track of the agricultural gantry itself, and the aerodynamic coefficient of the fertiliser. It was determined that, for the agricultural gantry with a distance of tracks of 3.5 m, a sufficient angular speed of the single-disc centrifugal tool is 15.5 rad·s−1, with a power demand for driving this at 0.35 kW·h. When using agricultural gantries of this type with an extended track width of up to 6 m, the necessary angular speed of the centrifugal tool for spreading fertiliser increases exponentially, to 318.2 rad·s−1, with the power demand for driving it increasing to the third power.
  • Kirje
    Application of the differential scanning calorimetry method in the study of the tomato fruits drying process
    (Estonian Academic Agricultural Society, 2020) Kuznietsova, Inha; Bandura, Valentyna; Paziuk, Vаdym; Tokarchuk, Oleksii; Kupchuk, Ihor
    Structural changes in the process of heating fresh fruit, sundried fruits and powder obtained from the dried tomato fruits were studied by differential scanning calorimetry method application. The kinetics of the shredded fruits in the dryer proves the prospects for using convective drying, which is performed for 295 minutes. The kinetic coefficients of drying and critical moisture content in the crushed fruits of tomato were determined. The kinetic coefficients were determined by the graphicalanalytical method: a = 0.839, ln(α) = 1.3 and α (1 s–1 ) = 0.262. It was determined that the critical maximum moisture content for drying the shredded fruits of tomatoes is 1.503% mm–1 , after what the process of combustion of vegetable tissue begins. The application of the differential scanning calorimetry (DSC) method allowed the fuller study of the mechanism of drying the fruits of tomato in different condition: fresh, sundried and dried. It was determined that the greatest amount of energy is consumed to remove free moisture (1,993 J g–1 ) from the fresh tomatoes. At the same time, when being cooled, crystallization in plant tissue occurs with the release of energy in the amount of 0.03922 J g –1 . When drying the previously sun-dried tomatoes the process of moisture removal and the partial decomposition of the compounds that are unstable to temperature is completed. At the same time, at the 129.61 °C temperature in the powder obtained from the fruits of tomatoes, melting of carbohydrates and other compounds occurred. Thus, this confirms the need to observe the normalized value of the mass fraction of moisture in the powders in the process of their packaging, storage and use. The basic technological system of production of powder from dried fruits of tomatoes is offered.
  • Kirje
    Aromatic plant Melissa officinalis extracts selectivity in various biomass crop and legume species
    (Estonian Academic Agricultural Society, 2020) Kanatas, Panagiotis; Gazoulis, Ioannis; Kakabouki, Ioanna; Papastylianou, Panayiota
    Allelopathic effects of various plants can be exploited for use against weeds; however, the selectivity in different crops is also important. In the current study, the effects of lemon balm (Melissa officinalis) allelochemicals on seed germination and seedling emergence of three biomass crops and three legume species were evaluated. Seed germination of rapeseed was reduced by 19, 30, 56, and 80% in the concentrations of 1, 2, 5 and 10%, respectively, as compared to the control group, whereas sweet sorghum seeds showed a more intermediate response and sunflower germination was affected only by the highest concentration. Seed germination of common bean was by 25, 34 and 60% lower at 1, 2 and 5% extract concentrations, respectively, in comparison to the control whereas up to 85% reduction of seed germination was recorded in 10% concentration. Peanut seed germination percentage ranged between 72 and 47% of control in 5 and 10% concentrations, respectively, while soybean germination was least affected from M. officinalis leaf extracts since it was reduced by only 25 and 41% in 5 and 10% concentrations, respectively, as compared to the control. Seedling emergence of rapeseed was reduced by 14, 25, 46, and 79% in the concentrations of 1, 2, 5 and 10%, respectively, as compared to the control whereas lemon balm extracts showed increased selectivity on the sunflower. Soybean emergence was reduced by only 27 and 46% in 5 and 10% concentrations, respectively, in comparison to the control whereas common bean’s seedling emergence was reduced up to 35% even in 2% concentration. Allelopathic response index values confirmed that sunflower and rapeseed were the least and most sensitive biomass crops to lemon balm allelochemicals, respectively, whereas sweet sorghum showed an intermediate response. Increased was the selectivity of the aqueous leaf extracts on soybean, whereas seed germination and seedling emergence of peanut were more affected and common bean was the most sensitive crop. Further research is needed to investigate the selectivity of M. officinalis and other aromatic plants’ allelochemicals on various crops and under different soil and climatic conditions to optimize their efficacy as tools of more eco-friendly weed management strategies.